Search

The paper presents the design and implementation of decentralized control for a PV–wind–battery hybrid off-grid system with limited power electronics devices and sensors. To perform well without using any maximum power point tracking (MPPT) technique from the wind turbine (WT) based on a permanent-magnet brushless DC generator (PMBLDCG) and solar panels (PVs) and balance the power in the system, a cascade control structure strategy based on a linear active disturbance rejection controller (LADRC) is developed for the two-switch DC-DC buck-boost converter. Moreover, to ensure an uninterruptible power supply to the connected loads with a constant voltage and frequency, a cascade d-q control structure based on LADRC is developed for the interfacing single-phase inverter. Furthermore, the modeling and controller parameters design are presented. The performance under all operation conditions of the hybrid off-grid configuration and its decentralized control is validated by simulation using MATLAB/Simulink and in real-time using a small-scale hardware prototype

Aerial robotics encompasses intricate kinematics and dynamics that govern the flight of quad-rotor systems. Among the various methods employed for flight control using microcontrollers like the ESP32 developed by ESPRESSIF; the proportional integral derivative (PID) controller stands out as a widely adopted approach. The ESP32 microcontroller offers a superior interface, delivering enhanced performance and response time, particularly in dynamic environments. This article delves into the implementation and viability of the ESP32 platform for communication with MATLAB/Simulink, as well as real-time data acquisition to control the attitude of quadcopter withe chassis F450. The PID controller was designed to specifically work with the ESP32 platform and rigorously tested on an actual quadcopter during flight operations. lastly, a comprehensive analysis of the data gained and empirical results from the physical model demonstrates that the proposed framework is effective.

The high penetration of renewable energy sources in modern distribution networks poses challenges for grid voltage regulation. In this study, a multi-agent distributed voltage control strategy based on the proximal Jacobian alternating direction method of multipliers (PJ-ADMM) is proposed for distribution power systems with a high penetration of photovoltaic (PV) resources coordinated with battery energy storage systems (BESS). In this context, the active and reactive power outputs of the PV are locally optimized through smart inverters to improve the grid voltage with minimum power loss. Uncertainties associated with solar energy generation and load demands are considered in the defined scenarios. This study consists of two phases. In the first phase, the voltage control problem is formulated as an optimization problem to regulate the voltages within an acceptable limit with fast convergence. In the second phase, a coordinated voltage control strategy for smart PV inverters and BESS is proposed to allocate the power capacity of the battery energy storage systems and the active power loss reduction. Finally, the proposed method is tested on modified IEEE 13-bus, 33-bus and 141-bus distribution systems using MATLAB/Simulink and MATPOWER. A comparison of the results of the voltage profiles with and without the control algorithm demonstrated the efficacy, robustness, and scalability of the distributed scheme for voltage improvement and optimal utilization of PV power under different scenarios.

Wind turbine emulators (WTE) have become a necessity for testing, developing, and improving design and control strategies in the renewable energy domain. The aim of this paper is to realize an experimental standalone wind energy conversion system emulator (WECSE) with improved torque and current control strategy using a nonlinear PI controller. The prototype was developed with a sep- arately excited DC motor to simulate the wind turbine by providing the required speed and torque for power generation using a directly driven wound-rotor synchronous generator and a power conversion system controlled by a mod- ified drift-free Perturb and Observe (P&O) Maximum Power Point Tracking algorithm (MPPT). The DC motor torque is controlled by an nonlinear PI con- troller regulator for an estimated current reference through a chopper driven by a dSPACE control board where the MATLAB/Simulink platform is used for wind turbine simulation. The proposed method was validated by experimental tests for different wind speeds and was compared with the conventional method. The experimental results have demonstrated that the control, emulation, and MPPT performances of the proposed method are significantly better.

The diagnosis of wind energy conversion systems (WECS) turns out to be necessary because of their relatively high cost of operation and maintenance. Wind turbines are hard-to-access structures, and they are often located in remote areas. Therefore, a remote diagnosis (e-diagnosis) is required. This paper proposes an alternative approach for the e-diagnosis of a WECS based on the discrete wavelet transform (DWT) and frequency analysis of the aero generator stator currents. To validate this approach, real-time hardware in the loop (HIL) is used to simulate in real-time the mathematical model of the induction generator on the OPAL-RT OP5600 platform to generate the stator currents and the rotor speed. The DWT is applied to the current signal, to generate the DWT signal, which has a huge number of points that are not supported for direct transmission by the Arduino Mega RobotDyn because of its limited sample time. The absolute values of the DWT peak points (MDWT) are sent as point’s packages form to the diagnosis station via the ESP8266 integrated Wi-Fi board of the Arduino Mega RobotDyn to monitor the SCIG states and determine the number of broken bars.

An electric vehicle uses multiple energy-storage systems to power the traction motor. Dual-source inverters (DSIs) are used for single-stage power conversion by skipping the dc/dc boost converter stage; therefore, eliminating the passive magnetic storing element which improves the overall efficiency of the drive; moreover, multiple energy-storage systems improve the power density of the system. This article discusses the fine control of a traction motor from zero speed to rated speed supplied through a dual-source inverter. Field-oriented control with space vector modulation technique is applied to achieve closed-loop control. Two dc sources are used, one having a higher-voltage battery and one a lower-voltage battery. The higher-voltage battery is the main battery which supplies power to the traction motor, whereas the lower-voltage battery supplies power to supplementary loads of the EV. This article presents improved dynamic behaviour of an induction-motor-driven EV fed from a dual-source inverter using modified closed-loop field-oriented control with space vector modulation. The improvement includes reduced control complexity due to space vector modulation and achieving the option of EV operation in an emergent situation using the same converter and control system. The simulated performance of the presented system is obtained in MATLAB/Simulink. A step-down experimental prototype is used for verification of effective control of the induction motor as the EV is under constant torque variable speed operation with real-time parameters such as power, power factor, current harmonics, and voltage/current stresses across the switch using two batteries individually.

This paper presents the performance evaluation of a proposed single-phase bidirectional active neutral-point-clamped (ANPC) five-level converter (5LC) for active filtering in grid-to-vehicle (G2V), vehicle-to-grid (V2G) and vehicle-to-home (V2H) applications. In the system, the 5LC is series-connected with an electric vehicle battery charger based on a dual active half-bridge DC-DC converter (DAHBC). A cascaded strategy with a proportional-resonant compensator controls the 5LC whereas the DAHBC is controlled by a single phase-shift technique. A performance comparison is carried out for the proposed topology versus three NPC/ANPC 5L converters found in literature with similar topologies. The simulation results obtained in MATLAB-SimPowerSystems along with the experimental results obtained from a laboratory prototype validate the following: a) the first two literature topologies have the highest efficiencies, but they are incapable of balancing the voltage of the split-capacitors what increases the total harmonic distortion of both the grid current in the G2V/V2G modes and the 5LC output voltage in the V2H mode while producing a sluggish transient response, b) the 3rd literature topology like the proposed one properly balance the capacitors voltage and achieve a faster dynamics, but at the expense of an efficiency reduction, and c) unlike the former topology that continuously applies a natural but wasting unfedback voltage balancing strategy, the proposed one that includes a closed-loop control allows achieving an ANPC 5LC with a superior performance featured by a higher efficiency, a reduced switches stress, a flatter power losses distribution and a better power quality improving under the three modes of operation.

In this paper, a composite control strategy for improved off-grid configuration based on photovoltaic (PV array), a wind turbine (WT), and a diesel engine (DE) generator to achieve high performance while supplying nonlinear loads is investigated. To operate the WT efficiently under variable speed conditions and to obtain accurate and fast convergence to the maximum global operating point without a speed sensor, an iterative interpolation method is integrated with the perturbation and observation (P&O) technique. To ensure the balance of power in the system and to achieve the maximum power from the PV array without using any maximum power point tracking (MPPT) method, and ensuring stable operation during the disturbance, a double-loop control strategy for a two-switches buck-boost converter is developed. Furthermore, to protect the synchronous generator of the diesel generator (DG) from the 5th and 7th order-harmonics created by the connected nonlinear loads and to solve the issue of the filter resonance, the interfacing three-phase inverter is controlled using an improved synchronous-reference frame algorithm (SRF) with virtual impedance active damping. The presented work demonstrates effective and efficient control along with improved performance and cost-effective option as compared to the similar works reported in the literature. The performance of the presented off-grid configuration and its developed composite control strategy are tested using MATLAB/Simulink and validated through small-scale hardware prototyping.

Presentación realizada en el marco del Proyecto: Seminario Internacional sobre Energías Renovables, ENERPY 2019, cuyo objetivo general era compartir con la comunidad científica, académica y la sociedad en general los últimos avances en el área de la ingeniería aplicada a las energías renovables y eficiencia energética.

A hybrid system combines two or more energy sources as an integrated unit to generate electricity. The nature of the sources associated varies between renewable and/or non-renewable energies. Such systems are becoming popular as stand-alone power systems to provide electricity, especially in off grid remote areas where diesel generators act as primary energy source. Wind–diesel systems are among the preferred solutions for new installations, as well as the upgrade of existing ones. However, efforts to address technical challenges towards energy transformation for sustainable development are multiple. The use of energy storage systems is a solution to reduce energy costs and environmental impacts. Indeed, efficient and distributed storage not only allows the electricity grid greater flexibility in the face of demand variations and greater robustness thanks to the decentralization of energy sources, it also offers a solution to increase the use of intermittent renewables in the energy mix. Among different technologies for electrical energy storage, compressed air energy storage is proven to achieve high wind energy penetration and optimal operation of diesel generators. This paper presents a computer model for performance evaluation of a wind–diesel hybrid system with compressed air energy storage. The model has been validated by comparing the results of a wind–diesel case study against those obtained using HOMER software (National Renewable Energy Laboratory, Golden, CO, United States). Different operation modes of the hybrid system are then explored. The impact of hybridization on time and frequency of operation for each power source, fuel consumption and energy dissipation has been determined. Recommendations are made on the choice of key parameters for system optimization.

Remote and isolated communities in Canada experience gaps in access to stable energy sources and must rely on diesel generators for heat and electricity. However, the cost and environmental impact resulting from the use of fossil fuels, especially in local energy production, heating, industrial processes and transportation are compelling reasons to support the development and deployment of renewable energy hybrid systems. This paper presents a computer model for economic analysis and risk assessment of a wind–diesel hybrid system with compressed air energy storage. The proposed model is developed from the point of view of the project investor and it includes technical, financial, risk and environmental analysis. Robustness is evaluated through sensitivity analysis. The model has been validated by comparing the results of a wind–diesel case study against those obtained using HOMER (National Renewable Energy Laboratory, Golden, CO, United States) and RETScreen (Natural Resources Canada, Government of Canada, Canada) software. The impact on economic performance of adding energy storage system in a wind–diesel hybrid system has been discussed. The obtained results demonstrate the feasibility of such hybrid system as a suitable power generator in terms of high net present value and internal rate of return, low cost of energy, as well as low risk assessment. In addition, the environmental impact is positive since less fuel is used.