Search

The safety of converters is key to the stable operation of AC/DC hybrid power grids after AC faults. Thyristor valve current is a direct manifestation of the converter observability, but there are no measuring elements inside the converter, so the thyristor valve current can be reflected only indirectly through external electrical quantities. This paper proposes a virtual measurement scheme based on the temporal features of the converter terminal current. First, under the action of the trigger pulse, the polarity characteristics of the AC current and temporal features between the valves are utilized to predictively estimate the valve state. Then, when the bypass paths form, the conduction state of valve is constructed based on the relationship between AC and DC current. Last, when the valve is to be shut-off in the bypass path, the blocking state of the valve is corrected based on the unidirectional conductance characteristics of the valve. According to the above analysis, combined with the topological current equation of the converter, the valve current can be calculated in the whole process. Through the simulation of the different valve states and different bypass paths and analysis of the field record data, the validity of the scheme proposed is verified.

To explore the design of a bidirectional isolated converter for usage with battery energy storage systems, the study aims to analyses this investigation. The change resulted in a reduced workload, which is an obvious advantage. We instead think that there will be no effect on the load-carrying capacity due to the increase in production. This research provides an alternating-direct-current renewable energy supply system. Solar, wind, power storage, and a load are included. This is an in-depth discussion of a power conversion converter's control system. Using an energy storage device in addition to the controller is feasible (ESSs). This research resulted in adaptive PI control, which is known for lowering link voltage and faster responses. Using this control system, you can cut down on both transient and static issues and also have a better shot at minimizing defects. MATLAB/Simulink is an application which does simulations. To evaluate the efficacy of an envisioned system, one simulates the systems and compares the results. The results show that the hybrid power supply model proposed may have a substantial effect on the energy supply to the isolated load and can be utilized to build a unique plan for a green data center.

This paper proposes a cooperative optimal power split (COPS) method for a group of intelligent electric vehicles with battery/supercapacitor hybrid energy storage systems (HESSs). To achieve good performance, the proposed COPS method is made up of the upper and lower layers: the upper layer aims at obtaining the optimal power demand sequence and sending it to the lower layer; the lower layer attempts to optimize the power split for HESS. Firstly, to ensure the performance of the proposed method in practice, the resistance of the battery and supercapacitor packs as well as the DC/DC converter efficiency are not assumed to be constants, but modeled well in the paper. Secondly, to achieve the optimal power demand sequence, an upper power demand sequence optimization problem is formulated based on distributed model predictive control (DMPC), in which energy demand is incorporated into the cost function. Thirdly, after receiving the optimal power demand sequence, a hybrid power split optimization strategy is presented to obtain the optimal power split, in which the lower HESS power split optimization problem is formulated based on DMPC to decrease battery aging process and energy consumption. Finally, an improved particle swarm optimization algorithm with multiple dynamic populations is used to solve the formulated upper and lower optimization problems. Simulation results demonstrate that, compared with the benchmark, the proposed COPS method can significantly extend battery lifespan and slightly decrease energy consumption.

This paper investigates the transient stability of power systems co-dominated by different types of grid-forming (GFM) devices. Synchronous generators (SGs and VSGs) and droop-controlled inverters are typical GFM devices in modern power systems. SGs/VSGs are able to provide inertia while droop-controlled inverters are generally inertialess. The transient stability of power systems dominated by homogeneous GFM devices has been extensively studied. Regarding the hybrid system jointly dominated by heterogeneous GFM devices, the transient stability is rarely reported. This paper aims to fill this gap. It is found that the synchronization behavior of the hybrid system can be described by a second-order motion equation, resembling the swing equation of SGs. Moreover, two significant differences from conventional power systems are discovered. The first is that the droop control dramatically enhances the damping effect, greatly affecting the transient stability region. The second is that the frequency state variable exhibits a jump at the moment of fault disturbances, thus impacting the post-fault initial-state location and stability assessment. The underlying mechanism behind the two new characteristics is clarified and the impact on the transient stability performance is analyzed and verified. The findings provide new insights into transient stability of power systems hosting heterogeneous devices.

Aiming at the problem of large harmonic distortion of grid-connected current in high-power grid-connected power generation system under weak sunlight, multiple hybrid power parallel inverters (MHPPIs) composed of some identical high-power inverters and one low-power inverter in parallel are proposed. According to the irradiance change of sunlight, the low power inverter operates alone or cooperates with the switching process between the high-power inverters to ensure the low grid-connected current harmonics. Where, any inverters operate in four common working processes, such as soft start-up, steady-state operation, abrupt change of current and soft stop. Due to the short running time of the dynamic process, most of the existing researches focus on the circulating current suppression under the steady-state condition. However, in engineering practice, the dynamic circulating current in the switching process between inverters is more likely to cause the over-current protection and other safe and stable operation problems of parallel inverters. Therefore, a dynamic circulating current suppression (DCCS) method with dynamic impedance matching for parallel inverters is proposed in this paper. The working process of the MHPPIs is equivalent to that of two inverters.

This paper proposes a framework for the stability analysis and control testing of marine hybrid power systems with DC power architecture. The dynamics of such active systems are increasingly influenced by interactive modes such as the highly dynamic loads and varying load sharing scenarios, electro-mechanical modes, and integration of energy storage systems (ESS). Hence, a dynamic model of the entire system is developed including the power electronics and ESS, electro-mechanical systems, different controllers–low level and high level– and propulsion loads. The proposed analytical model is used to establish not only the small-signal stability analysis but also time-domain simulations. Then, a set of dynamic analyses and tests has been performed to identify the stability challenges that a vessel may be exposed to during a real operation. The suggestions for improving the system performance are given as the control modification at different levels. To emulate the real operation, a ship operational profile is used for the tests. Finally, the proposed dynamic model is verified with the experimental results conducted in a full-scale hybrid power systems laboratory. The results show that the system dynamics can be affected significantly by the interaction of the high-level and low-level control of the converters, which is usually neglected in conventional models.

In this article, a high-efficiency broadband millimeter-wave (mm-Wave) integrated power amplifier (PA) with a low-loss slotline-based power combing technique is proposed. The proposed slotline-based power combiner consists of grounded coplanar waveguide (GCPW)-to-slotline transitions and folded slots to simultaneously achieve power combining and impedance matching. This technique provides a broadband parallel-series combining method to enhance the output power of PAs at mm-Wave frequencies while maintaining the compact area and high efficiency. As a proof of concept, a compact four-to-one hybrid power combiner is implemented in a 130-nm SiGe BiCMOS back-end-of-line (BEOL) process, which leads to a small die area of 126 μm x 240 μm and a low measured insertion loss of 0.5 dB. The 3-dB bandwidth is over 80 GHz covering the whole G-band (140-220 GHz). Based on this structure, a high-efficiency mm-Wave PA has been fabricated in the 130-nm SiGe BiCMOS technology. The three-stage PA achieves a peak power gain of 30.7 dB, 3-dB small-signal gain bandwidth of 40 GHz from 142 to 182 GHz, a measured maximum saturated output power of 18.1 dBm, and a peak power-added efficiency (PAE) of 12.4% at 161 GHz. The extremely compact power combining methodology leads to a small core area of 488 μm x 214 μm and an output power per unit die area of 662 mW/mm².

This paper bestows 3-phase grid interfaced solar-wind hybrid renewable energy system (RES), feeding three-phase loads. The proposed system includes solar photovoltaic, permanent magnet based synchronous generator (PMSG), DC-DC converter, maximum power point tracker (MPPT) based on incremental conductance, three phases IGBT based voltage source converter (VSC), with a third order generalized integrator (TOGI) control technique. This control technique bestows multifunctional capabilities as harmonic mitigations, load balancing, and reactive power compensation. A fundamental component of load current is extracted by TOGI based controller, and further it is utilized to provide switching pulses to VSC for power quality enrichment. The fuzzy logic-based controller is used for loss computation of VSC as well as for maintaining DC link voltage. Moreover, fuzzy logic provides better dynamic performance compared to conventional PI controller. The results are presented in many aspects for linear and nonlinear loads such as, intermittent nature of solar and wind as well as disturbances in the system. A comparative analysis between proposed TOGI based controller and conventional control algorithm has been presented. Test results are performed by using MATLAB/ Simulink environment and demonstrate, AC-grid current is maintained within the IEEE-519 standard.

This paper contributes to the feasibility of a wind turbine/battery system with a hybrid power optimization controller. The proposed method is based on a mathematical optimization approach and allows to achieve an efficient operation of the maximum power point tracking (MPPT) algorithms to obtain an optimal performance level of the wind system and a minimal stress on the battery storage. The different powers have been controlled by a power management control (PMC) method. The objectives of the PMC based are, in first part to satisfy the load power demand and in second part to maintain the state of charge of the battery bank to prevent blackout and to extend the batteries life. A measurement of wind speeds was made during a whole day using a data acquisition system at the laboratory. Also, the different wind turbine parameters were identified at the same Laboratory. All these parameters have been used in simulation models in order to obtain the most realistic mathematical models that are close to the experiment. Real time simulation is performed using RT LAB simulator and the obtained results were matching those obtained in numerical simulation using Matlab/Simulink. The obtained results under two different wind speed profile, with the different comparisons are presented to show the feasibility and the improvement of the proposed study in terms of power, efficiency, time response and effect on battery state of charge under two different wind speeds profile.

With the rapid development of EV in the transportation system, its increasing influence on the power system has attracted more and more attention in recent years. Under such a background, a virtual EV energy network (VEEN) in traffic level coupled with the correspond-ing power grid is formed in this paper, considering the energy carried by EVs in a specified area as a virtual node. To further identify the vulnera-ble components in the coupled energy network, a hybrid approach based on a complex network (CN) is presented. A hybrid power transfer distri-bution factor (HPTDF) is proposed for the coupled energy network con-sidering the variation of VEENs over time. Then, the line betweenness and the modified time-varying coupling net-ability are designed to eval-uate the vulnerability of the coupled network. Furthermore, to demon-strate the applicability of the proposed models, three case studies are per-formed on the 39-bus IEEE power network coupled with a 19-node VEEN. The simulation result verifies the effectiveness of the method in terms of identifying the critical lines in a coupled energy network, and a vulnerability assessment progress by designing a slow-fast dynamic cas-cade failure simulator in this paper verifies that a VEEN layer coupling defense strategy can decrease the vulnerability of a power grid layer un-der random attacks.

The fuel cell power generation systems are using in most of the present hybrid Electric Vehicle (EV) technology. The output characteristics of fuel cell arenonlinear. Also, the fuel operating point fluctuate continuously based on its operating temperature condition. In order to track and stabilize the operating point fuel cell, an Artificial Neuro Fuzzy Inference System-Genetic Algorithm Optimization (ANFIS-GAO) method is used. The merits of this proposed Maximum Power Point Tracking Technique (MPPT) are high extraction power capacity, high reliability, less oscillations, and fast tracking speed. The fuel cell is having a drawback of high output current and its less output voltage generation capability. To overcome this issue, in this work, an interleaved dc-dc converter circuit is used to enhance the fuel cell energy. The advantages of the proposed dc-dc converter are low voltage stress across the switches, less input current ripples, faster response, reduced electromagnetic emission, and high reliability. The proposed hybrid power point tracking technique performance is evaluated against with the Variable Step-Perturb & Observe (VS-P&O) algorithm. The MATLAB/Simulink environment is used for the performance analysis of proposed system.

Reliable and sustainable energy supply is essential for the development of remote rural areas, especially in the context of stringent carbon emission reduction target. This study aims to demonstrate the techno-economic feasibility of a stand-alone hybrid renewable energy system (HRES) to satisfy the electric and hydrogen load for remote rural communities, where a case study of a village in West China is presented. By performing simulation and optimization, the most cost-competitive system configuration is identified, the net present cost (NPC), cost of energy (COE) and cost of hydrogen (COH) of which are $1.26 M, $0.162/kWh and $12.5/kg, respectively. Compared with grid extension, the proposed system is more economical with a breakeven grid extension distance (BGED) of 16.15 km, and less carbon footprint with CO2 emission avoidance of around 375.44 ton/year. In addition, sensitivity analysis on annual average hydrogen load growth and system capacity shortfall friction have been performed. The results indicated that the implementation of a hybrid power system can be a reliable and economic viable solution for remote rural electrification and decarbonizing local transport sector, whilst social and environmental benefits are also achieved.

Thanks to its fast self-synchronization capability, the virtual oscillator control (VOC) has become an emerging control technique for grid-connected inverters, especially in single-phase applications. Nevertheless, the nonlinearity of VOC inverters impacts its dynamic behavior, and there is a trade-off between the system stability and accurate power regulation in VOC-based microgrids. This paper studies the dynamic stability of VOC inverters for guiding the parameter design. Then, based on the analysis result, an improved VOC strategy with hybrid power regulation structure is proposed for improving both the system stability and power regulation of VOC-based microgrids. First, a dynamic phasor (DP) model of single-phase VOC-based microgrids with multiple control loops is developed. Second, a stability region analysis of VOC parameters is performed, the proper mode setting and robust parameter design of VOC inverters are provided. Third, the improved VOC strategy is presented, achieving accurate power sharing, fast voltage recovery and adequate stability margin. The proposed parameter design and improved VOC strategy are validated by simulation and hardware-in the-loop experiment.

This paper presents a hybrid power supply system for robot actuators that has multiple voltage buses and hybrid energy storage including a supercapacitor. The proposed system utilizes a multi-tasking control scheme to reduce the component count. To improve the system response of mobile robots, a supercapacitor is employed in the proposed architecture along with a battery. The proposed circuit offers two higher voltage buses than the main battery voltage in order to employ higher voltage actuators with a lower current for a higher power density. To manage the DC buses and the supercapacitor’s bidirectional power flow, three switching devices are used in the proposed structure, reducing a switching device and an inductor. A control structure using a mixed switching strategy has been developed to regulate the higher-voltage buses and the supercapacitor’s power flow simultaneously. The proposed control and circuit structure are validated by hardware experiments.

This work presents a 48-1V dc-dc converter with an on-chip switch and gallium nitride (GaN) hybrid power conversion. By series connecting a 12-level Dickson switched-capacitor with a two-phase switched-inductor circuit, the capacitors take over most of the 48-V voltage stresses. The circuit, thus, reduces to an equivalent 4-1V converter, making the on-chip 5-V transistor applicable for a 48-V high-voltage design. Due to the easy integration of on-chip switches and superior switch figures of merit over other 48-1V counterparts, this proposed design is able to achieve the highest switching frequency, the lowest external switch count, and the improved power density compared with other prior-state-of-the-arts. The prototype was fabricated using a 0.18-μm BCD process with an evaluation board volume of 17 mm x 15 mm x 2.6 mm. The converter achieves a maximum 8-A loading capacity with the input range from 36 to 60 V and the output from 0.5 to 1 V. The measured peak power efficiency is 90.2%, and the power density is 998 A/in³ considering the power stage volume.

In this paper, we consider a simultaneous wireless information and hybrid power transfer system for cellular green networks. The small cells (SCs) use hybrid power of on-grid power and green energy harvested from environments, whilst the user equipments (UEs) are enabled by a power-splitting receiver. A quality-of-service (QoS) constrained problem is designed to maximize energy efficiency (EE) considering joint strategies of hybrid power allocation, resource block assignment, and power splitting ratio adjustment. We propose a joint wireless charging and hybrid power based resource allocation (J-WHA) algorithm by transforming the non-concave EE problem into a solvable one based on proved concavity property and Karush-Kuhn-Tucker (KKT) conditions. Moreover, a separated wireless charging and hybrid power based resource allocation (S-WHA) algorithm is proposed to obtain sub-optimal solutions with lower computational complexity. Simulation results demonstrate the convergence of both proposed algorithms in relation to transmission power utilization, wireless charging amount, and system EE. It is shown that the proposed J-WHA and S-WHA algorithms outperform existing schemes in terms of EE performance.

The source of electricity supply in isolated areas is commonly from diesel or other fossil fuel-based generation systems. However, the increasing cost and harmful emissions of these fuels have led researchers to seek alternative solutions in providing electricity. Hence, harnessing renewable resources can be a favourable solution in lowering the dependency on fossil fuels. The Strait of Malacca is blessed with tidal current energy, a research was conducted to design a hybrid renewable energy system (HRES) that consists of tidal current and solar energy as its sources along with backup power such as generators to support the electrical demand of a lighthouse. A simulation method is used to determine and compare the optimal configuration of the HRES with the diesel generator-based system. An evaluation of all possible scenarios of standalone systems was carried out by considering the amount of fuel consumption and pollutant emittance, capacity shortage, excess electricity production, unmet energy and renewable fraction parameters of each system scenario. From the findings, the hybrid energy system of Scenario A that consists of tidal turbines, PVs, generator, battery, and converter produces better results where the diesel fuel consumption can be reduced up to 84% in comparison with the standalone generator-based system.

Considering the current challenges posed by energy structural transformation on remote islands, the technical and economic assessment of a hybrid renewable power system were performed considering the Huraa Island of Maldives as a case study. This work models and discusses possible hybrid power system configuration modes based on varying combinations of diesel power, solar photovoltaic (PV) power, wind power, and battery storage. For each mode, the effects of the installed capacity on renewable penetration (RP) and levelized cost of electricity (LCOE) were analyzed. Furthermore, the configuration modes were compared, and optimal operation schemes were developed by considering RP, LCOE, and CO2 emissions. The results suggest that the use of a high-rated PV power is optimal owing to its high RP and low LCOE. However, when wind power is available, a wind power rating of 1000 kW is an optimal solution, followed by a 500-kW rating; when battery storage is used, a battery capacity of 4000 kWh is ideal. Moreover, it is unnecessary to combine battery storage with these power schemes when an RP

Advanced nonconventional renewable and alternative green energy technologies which are used for generation of electrical power have shown real promise and received renewed interest in recent years due to an increasing concern of environmental issues of greenhouse gas emissions, air pollution, and the limitations and conservation of natural energy resources. Solar-photovoltaic (PV) systems directly convert renewable solar energy into green electrical energy. However, their power production and efficiencies tend to decrease when operating at relatively higher temperatures. Therefore, reducing the temperature of PV modules using efficient cooling methods would improve their performances. Thermoelectric power generation (TEG) technology could be used to convert a portion of the waste-heat energy dissipated from PV systems, thus cooling them, and at the same time generates extra power. Hence, hybrid photovoltaic-thermoelectric power generation (HPV-TEG) systems integrate TEG modules with a PV module to form a more efficient power generation system. The main objective of this paper is to investigate the viability and performance characteristics of a hybrid HPV-TEG through detailed lab-simulated tests. Experimental results and in thermal images showed that the HPV-TEG system was able to generate more DC power than the solo PV system while operating at higher irradiance intensities and lower TEG’s inlet coolant temperature. At the irradiance of 615W/m2, the power generation from the hybrid HPV-TEG system increased by 4.1% compared to the solo PV system. The results also indicated that when the irradiance was increased to 750W/m2, the power generated from the hybrid system increased to approximately 8.6% higher than the power generated from the solo PV system at the same irradiance. The integration of the concentrators in the hybrid PV system increased the maximum power point by 23.3% compared to the hybrid PV system without concentrators.

In this research work, a novel approach is proposed by introducing numerous scaling factors in the original equilibrium optimization technique which can be named as modified equilibrium optimization (MEO) algorithm and is utilized for the load frequency control (LFC) of two-area hybrid distributed power system. The introduced MEO meta-heuristic algorithm is compared with a standard EO algorithm and other meta-heuristic algorithms for different standard benchmark test functions. Furthermore, the genuine utilization of the MEO algorithm is tried by designing a multi-stage PID (MS-PID) controller for frequency regulation of the power system with distributed energy sources including renewable sources. The supremacy of the reinforced MEO methodology-based MS-PID controller for enhanced frequency regulation is presented and its outcomes are compared with the EO-tuned PID and MS-PID. From the performance comparison, it is recognized that the MEO-based MS-PID controller is more efficacious.

In recent years, due to the strengthening of our country’s comprehensive strength, the rapid development of science and technology and artificial intelligence has also attracted people’s attention. Artificial intelligence is a highly applicable subject, which has very good applications in power systems. In the experiment, the open circuit voltage method and the ampere-hour integration method are used to estimate the SOC of the lithium battery and the particle swarm energy management algorithm is used to allocate the output power of the fuel cell and the lithium battery. The particle swarm algorithm module calls the dual source hybrid power system module through the sim function to convert the actual value input in the system into a fuzzy quantity suitable for fuzzy control. The energy management strategy based on particle swarm optimization and fuzzy control was tested based on working conditions under the comprehensive test bench. Finally, the matching of the hybrid system is analyzed from the structure, component parameters, control strategy, and driving cycle of the vehicle. The experimental data show that the total fuel consumption of the three sets of experiments is averaged to get a fuel consumption rate of 26.3 m3/100 km for the hybrid city bus under the optimized energy management strategy. The results show that the real-time energy management strategy based on particle swarm algorithm can significantly improve the real-time performance of traditional instantaneous energy management strategies while reducing fuel consumption.

This work primarily focuses on electrical characteristics of a hybrid power system (HPS) incorporating renewable energy generation (REG) (HPSREG). The major components of HPSREG are the resources coordinated with multi-unit of photovoltaic cells, multi-unit of wind turbine generators, a diesel engine generator (DEG), energy storage system (ESS) with diverse nature and an electric vehicle (EV). The performance characteristics of HPSREG are determined by constant generation of power from the various sources as well as varying load perturbations. As the variation in load demand will introduce fluctuation in frequency and power with constant generation. In few of overcome the frequency and power deviation under both the above-mentioned generation and load demand conditions, proper control technique is required. In order to control the deviation in frequency and power, an integration in the environment of fractional order (FO) calculus for proportional–integral–derivative (PID) controller and fuzzy controller, termed with FO-Fuzzy PID controller tuned with quasi-opposition based harmonic search (QOHS) algorithm has been proposed. The results acquired with the proposed FO-Fuzzy-PID controller are then analyzed along with FO-PID and PID controller route for quantify effectiveness for the same under the considered cases to determine the effectiveness of the algorithm undertaken. Sensitivity investigation is also conducted in order to show the strength of the technique under study of differences in HPSREG parameters of magnitude.

Power system operations are unavoidably influenced by forecast uncertainties. The forecast uncertainty's effect on operations was quantified in individual systems, however, was seldom investigated in a hybrid system. This study aims to quantify the effect of forecast uncertainties on the hybrid hydro–photovoltaic system operation. First, the operation model is built considering streamflow and photovoltaic forecast uncertainties with long- and short-time scales. Second, total release uncertainty is determined from the sum of squares for releases under different forecast scenarios. Finally, a variance partitioning method is used to divide the total release uncertainty into the uncertainties induced by individual forecast errors. Longyangxia hybrid hydro–photovoltaic power plant from China was selected as a case study. Results provide following insights: (1) long-term inflow forecast uncertainty accounts for 98.89% of the contribution to the long-term release uncertainty, while photovoltaic uncertainty accounts for 1.11%; (2) long-term inflow forecast uncertainty still dominates the short-term release uncertainty, with the contribution of 62.06%; and (3) the total release uncertainty decreases in long-term hybrid operation compared with the reservoir operation, indicating the complementary relationship between long-term hydropower and photovoltaic power. These implications highlight the importance of improving forecast accuracies for varied energy sources at different time scales.

This paper proposes a capacitive bridge-type superconducting fault current limiter (CB-SFCL) to address the most concerning issue with the grid connected hybrid power system by improving the transient performance. The hybrid system incorporates a doubly fed induction generator (DFIG) based wind farm, a solar photovoltaic (PV) system and a synchronous generator (SG) based power system. The CB-SFCL incorporates a high temperature superconductor (HTS) along with a power capacitor to provide adequate reactive power support before and after the fault. The capacitor is kept inactive during normal operation by a control circuit to ensure seamless operation. During fault, the capacitor gets connected in series with the HTS and suppress the fault current. The performance of the CB-SFCL is investigated by proper graphical and mathematical analyses and conclusions are obtained by comparing them with that of the conventional bridge-type superconducting fault current limiter (BSFCL) and the capacitive bridge-type fault current limiter (CBFCL). The analyses support the theoretical superiority of the CB-SFCL over the BSFCL and the CBFCL by a satisfying margin.

The International Marine Organization (IMO) regulations forcing shipbuilders to use electric ships to reducing pollution emitted from ship engines. Renewable energy resources are the perfect solution to solve this issue. The ship’s hybrid energy power system consists of several non-homogeneous energy resources diesel generator, renewable energy source or more, energy-storing system, and may hydrogen source as fuel cells. The EMS manages and controls the balance between the different types of sources and loads demand to ensure system stability and dependability. In this paper, energy management strategy (EMS) for fuel cell and battery hybrid systems is an essential property of controlling power flow between sources. A crucial ingredient of an intelligent control strategy is to manage the flow of a hybrid system corresponding to the changing of the load demand and battery state of charge (SoC) using the ANFIS/Simulink toolbox implements a case study architecture. This paper proposes a hybrid energy source for use in a naval ship’s silent mode of operation while looking for submarines with a low acoustic signature based on adaptive neuro-fuzzy procedures. The main objective of this analysis is to investigate the efficiency of the proposed system preserving compared with practical results obtained from previous work. These studies provide valuable understandings into hybrid power systems’ flow of EMS on the marine field.

In this paper, an improved optimization algorithm is proposed to overcome the original Rao algorithm limitations (i.e., different characteristics in exploration and exploitation) and enhance the performance of the original Rao algorithm. In the improved algorithm, the self-adaptive multi-population and Levy flight methods are utilized in the original Rao algorithm. The improved algorithm is called I_Rao_3. The improved algorithm’s efficiency is confirmed by comparing it to the original Rao algorithm utilizing various standard benchmark test functions. Moreover, the proposed I_Rao_3 algorithm is utilized to improve the frequency response in a hybrid renewable power grid by fine-tuning the proportional-integral-derivative (PID) controller parameters. The targeted system used for this study is a hybrid power grid, which encompasses conventional generating stations (i.e., thermal power plants), renewable power stations (i.e., PV and wind power stations) for the analysis of the load frequency control (LFC) issue. Unlike other previously published works, this study considers the impact of DC links in parallel to AC links to interconnect the two-hybrid renewable power system area. In addition, the nonlinearities effects (i.e., generation rate constraint and a governor dead band) are applied to each area in order to achieve a more realistic study. The superiority of the proposed PID controller-based I_Rao_3 algorithm is endorsed by comparing its performance with many other optimization algorithms.

The paper offers a method for developing a universal system of automated design of an optimal structure of autonomous distributed hybrid energy complexes (ADHEC) and the means for regulation of the energy balance therein, i.e. control of the power flows circulating in the mentioned system. ADHEC will not only help unload the existing power system, but can also be used to produce “green” hydrogen. In general, the design of the optimal structure of ADHEC includes the following stages (subtasks): data research and creation of a statistical database of electric loads of consumers, the wind speed in the region under consideration, the hydroelectric potential of mountain and lowland rivers, and the solar energy, as well as the research and development of a database of converters of wind and water energy into electrical energy. The paper focused on the task of designing the optimal structure of the distributed hybrid generation system that will ensure the desired level of power generation at a minimal cost and with necessary functional reliability.

This manuscript presents a hybrid method for smart energy management (EM) in grid connected microgrid (MG) system. The grid connected micro grid system consists of photovoltaic (PV), wind turbine (...

The paper analyzes the existing design schemes of hybrid power machines with a coolant moving in the jacket space due to the vacuum at the suction and introduces a new design of a single-stage single-cylinder piston hybrid power machine with two suction valves, in which the forced movement of the coolant in the forward direction is provided due to the vacuum at the suction, and in the reverse direction due to the pressure drop of the compressed gas. The analysis of the reverse expansion process allowed us to determine the value of the reduced dead space, which directly affects the volumetric feed rate of the reciprocating compressor and the feed rate in general. The parametric analysis made it possible to determine the influence of the main design and operating parameters on the value of the reduced dead space and accordingly on the volumetric feed rate. The results obtained can be useful in the design and research of reciprocating hybrid power machines with the forced movement of the coolant.

This paper proposes an energy management strategy for a fuel cell (FC) hybrid power system based on dynamic programming and state machine strategy, which takes into account the durability of the FC and the hydrogen consumption of the system. The strategy first uses the principle of dynamic programming to solve the optimal power distribution between the FC and supercapacitor (SC), and then uses the optimization results of dynamic programming to update the threshold values in each state of the finite state machine to realize real-time management of the output power of the FC and SC. An FC/SC hybrid tramway simulation platform is established based on RT-LAB real-time simulator. The compared results verify that the proposed EMS can improve the durability of the FC, increase its working time in the high-efficiency range, effectively reduce the hydrogen consumption, and keep the state of charge in an ideal range.

Proton exchange membrane fuel cell (PEMFC)/battery hybrid electric vehicle is considered as promising transportation due to its eco-friendly characteristics. This article investigates a fuzzy logic (FL)-based adaptive backstepping sliding-mode control (BSMC) approach to generate stable charging current and voltage for battery charging applications on a non-plug-in PEMFC vehicle. An adaptive BSMC is proposed to address nonlinearities and disturbances caused by dc/dc buck converter, PEMFC, and equivalent load variations of batteries. Moreover, an FL-based approximation is utilized to estimate the time-varying equivalent load of batteries through the adaptive laws obtained by the defined Lyapunov function and can offer assistance estimating the state of charge (SOC) of batteries. Simulation comparisons between a proportional–integral (PI) control and the proposed FL-based adaptive BSMC were executed subsequently under certain conditions to validate the efficacy. Finally, experiments on the PEMFC/battery hybrid power system scaling prototype via NI (PCI-6229)-LabVIEW platform were implemented to test the charging performance of the proposed approach. The comparative results indicated that the FL-based adaptive BSMC method could regulate charging current and voltage against disturbance and uncertainty and estimate the equivalent load of batteries accurately.

This paper presents a comparative study of two promising real-time energy management strategies for fuel cell electric vehicle applications: adaptive equivalent consumption minimization strategy (A-ECMS), and stochastic dynamic programming (SDP). An off-line algorithm –classic dynamic programming - provides reference results. On-line and off-line strategies are tested both in simulation and using a dedicated test bench completely consistent with an electric scooter powertrain. The hybrid power source combines a fuel cell, a supercapacitor pack and two related power converters. The system model is carefully calibrated using experimental data. This allows meaningful identification of parameters of the various strategies. The model data is determined using a motorcycle certification driving cycle. The robustness of each strategy is then analyzed using a large number of random driving cycles. Experimental and simulation results show that a specific SDP approach, based on Markov chain modeling, has the best overall performance in real-world driving conditions. It achieves the minimum average hydrogen consumption while respecting the state-sustaining constraint. Conversely, the A-ECMS results lack robustness and show poor performance indexes when facing unknown real world power demand profile. In conclusion, the present results indicate SDP is an interesting approach for future hybrid source energy allocation.

A novel two-cylinder single-stage piston hybrid power machine with liquid movement effectuated by vacuum on the suction side is described. The presented results of an experimental study on the cooling efficiency of the cylinder-piston group and the effect of compressor cooling on the feed rate show that the temperature of the valve plate decreases by 10–12 K, while that of the cylinder walls decreases by 7–8 K. Based on the analysis of the working processes of a reciprocating compressor, the effect of cooling on the feed rate was found to be ambiguous, leading both to its possible increase and reduction; this was confirmed as a result of experimental studies.

The manuscript addresses a robust three-dimensional fuzzy-PID controller (Fuzzy-3D PID) to control frequency of a diverse energy source integrated hybrid power system under various loadings. In ord...

The proposition in this paper is the use of the whale optimization algorithm (WOA) for optimizing the novel Fuzzy-PID plus PID hybrid controller as used for frequency regulation in a hybrid power system (HPS) comprising a microgrid structure—a cluster of resources—reheat thermal power system, and STPS—the solar thermal power system. The proposed use of WOA technique for frequency regulation in HPS could be termed as a novel proposition at a time when not many articles have been reported in the literature around the use of WOA for the said purpose in such like systems. The relative supremacy of WOA over other recently proposed evolutionary optimization algorithms viz. multi-verse optimizer, grey wolf optimizer, grasshopper optimization algorithm, and differential evolution algorithm is proven via comparative analysis of the load frequency performance of the HPS with Fuzzy-PID plus PID hybrid controller, optimized using all of these algorithms, as the control strategy in the system. Besides, the paper also implements the conventional PI, PID and Fuzzy-PID controllers, optimized using WOA, with an objective of assessing the effectiveness of Fuzzy-PID plus PID hybrid controller as against these controllers. The study also assesses the robustness of the proposed control scheme against parametric variations in the range of ± 10%. The proposed WOA optimized Fuzzy-PID plus PID hybrid controller exhibits the best performance compared to other controllers which proves the efficacy of WOA in load frequency control studies.

The Nigerian power problem resulted to incessant and erratic supply of electricity and this has destroyed many industrial processes in the country. It has reduced productivity and has increased unemployment rate in the country to over 50million (this figure is over 70% of Nigerian youths). This has led many of the youths in the country to crime. It has led to the deaths of many innocent people in the country. As of 2016, the electricity energy consumption in the world from the world fact book revealed that the average power per capita (watts per person) in the United States is 1,377 Watts. In Canada, it is 1704 Watts per person and in South Africa; it is 445 Watts per person and in Australia, average power per capita (watts per person) is as high as 1,112 Watts. Whereas, the average electricity consumed in watts per person in Nigeria is just 14 Watts. Unfortunately, this has put the country in a rank of 189 out of 219 countries estimated. In this research work, a Hybrid Electric Power System (HEPS) which comprises Hydro Electric Power Plant (HEPP) and Diesel Generator (DG) was modelled and a control algorithm was established to improve the performance of the system. Hybrid power system mathematical and Simulink models were developed. The output power of the developed Simulink model was be optimized using optimum power point optimization techniques and control algorithms. Simulink models of the two components of the Hybrid Electric Power System were produced using MATLAB/Simulink software. The develop Simulink models was interconnected and final model was developed. The results obtained revealed that the problems associated with conventional methods of power generation was overcomed by the development of this renewable and non-renewable energy resources Hybrid Electric Power System (HEPS) models.

In this paper, two bandpass–bandpass diplexers, based on L-, T- and rectangular-shaped resonators are designed and analyzed, which are used to design a novel hybrid power amplifier (HPA) in 5G applications. By using the designed diplexers, the presented hybrid power amplifier structure can operate at two desired frequencies in two desired classes of operation. The equivalent circuits and transfer functions are extracted to study the behavior of the filters responses.Query However, the proposed analysis can be used to locate transmission zeros at desired frequencies, which can ease the design procedures of the diplexers at any desired frequency. The proposed HPA and diplexers are designed at 1.5 GHz and 2.1 GHz operating frequencies. To verify the results, one of the proposed diplexers is fabricated, in which the obtained measured results are in good agreement with the simulated results. The insertion losses for the fabricated diplexer are less than 0.7 dB and the isolation value is achieved better than 27 dB in the operating frequencies. The overall sizes of the proposed diplexers are about (0.165λg × 0.198λg) and (0.75λg × 0.07λg). The results of the designed HPA show that the proposed HPA has desirable specifications. The drain efficiency (DE) and power added efficiency (PAE) of the proposed HPA are 60% and 53% at 1.5 GHz operating frequency while, the DE and PAE are 65% and 51.5% at 2.1 GHz respectively.

Purpose The purpose of this paper is to analyze the performance of the gas turbine cycle integrated with solid oxide fuel cell technology. In the present work, intermediate temperature solid oxide fuel cell has been considered, as it is economical, can attain an activation temperature in a quick time, and also have a longer life compared to a high-temperature solid oxide fuel cell, which helps in the commercialization and can generate two ways of electricity as a hybrid configuration. Design/methodology/approach The conceptualized cycle has been analyzed with the help of computer code developed in MATLAB with the help of governing equations. In this work, the focus is on the performance investigation of a Gas turbine intermediate temperature solid oxide fuel cell hybrid cycle. The work also analyzes the performance behavior of the proposed cycle with various design and operating parameters. Findings It is found that the power generation efficiency of the IT-SOFC-GT hybrid system reaches up to 60% (LHV) for specific design and operating conditions. The cycle calculations of an IT-SOFC-GT hybrid system and its conceptual design have been presented in this work. Originality/value The unique feature of this work is that IT-SOFC has been adopted for integration instead of HT-SOFC, and this work also provides the performance behavior of the hybrid system with varying design and operating parameters, which is the novelty of this work. This work has significant scientific merit, as the cost involved for the commercialization of IT-SOFC is comparatively lower than HT-SOFC and provides a good option to energy manufacturers for generating clean energy at a low cost.

The high-penetration of distributed generation technologies in the form of MicroGrids (MGs), in recent years, has increased the risk of frequency instability since their energy is supplied by renewable energy resources (RESs) with uncertain nature. Under such circumstances, providing an MG model with an efficient load frequency control (LFC) has a fundamental role in restoring the stability of the unstructured power system. In this study, a hybrid power system with the application of the Tidal Power Unit (TPU) and Vehicle-to-Grid (V2G) is effectively planed as an isolated MG. A new fractional gradient descent (FGD) based on a single-input interval type-2 fuzzy logic controller (SIT2-FLC) is suggested as the main LFC controller, where the footprint of uncertainty (FOU) coefficient of the SIT2-FLC is specifically adjusted to enhance the LFC performance. Additionally, a deep deterministic policy gradient (DDPG) with the actor-critic framework is considered to generate the supplementary control action, which is useful for the frequency stabilization by adapting to the randomness of load disturbances and RESs. Lastly, a model-in-the-loop (MiL) simulation is conducted to appraise the feasibility and applicability of the suggested design method from a systemic perspective.

The concept of the hybrid power system in electric vehicles means that there are many sources in this electric vehicle. The electric vehicle of two-wheel drives motors doesn't exploit the two front wheel; this kind of electric vehicle prompted us to propose using the front wheels in electric vehicle energy management, which creates another energy source. The hybrid vehicle can associate more than one source to each other to secure a long time working. The two rear wheels are generally controlled by classical controllers as the DTC-SVM controller that is one of many methods to control a motor's speed. It Based on three classical controllers. We want to replace the PI speed controller with an intelligent controller and show the possibility of integrating it in this kind of control. In this paper, we exploit the electric vehicle's Kinetic energy in energy management by combining the permanent magnet synchronous generator in the vehicle's front wheels, and integrating the ANFIS controller with back motors. The generator's power represents about 19% of the total electric vehicle power. The ANFIS management strategy gave the best results 96.6 as efficiency and the smallest consumption of Air/fuel compared with the others methods about 55.75–199 (Ipm).