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The problems of manual control of a manipulator using motion controllers with a logical output signal are considered. Controllers of various designs and logic of action are considered. Various control modes and principles are highlighted that allow the simultaneous operation of several drives using the example of a mechanism with four degrees of freedom and a remote center of rotation. Recommendations are given for choosing control methods and laws when developing spatial manipulators. [ABSTRACT FROM AUTHOR]

This paper proposes a novel hybrid technique for enhancing power quality (PQ) in distributed generation (DG) systems by deploying a unified power quality conditioner (UPQC). Here, the proposed hybrid method is the joint execution of white shark optimizer (WSO) and recalling-enhanced recurrent neural network (RERNN), called the WSO-RERNN technique. The primary objective of this novel approach is to effectively mitigate voltage sag and reduce voltage harmonics under varying load conditions. It is important to investigate the voltage sag, swell and harmonic distortion of the system to obtain an enhanced PQ of the energy supply. Therefore, this paper shows the brief impact of PQ in DG utilizing the proposed unified PQ conditioner controller. The WSO-RERNN control technique enhances the performance of the UPQC controller by providing the optimal control signal. By then, the efficiency of the proposed approach is done in MATLAB, and the performance is compared with those of existing optimization techniques, including Ant Lion Optimizer (ALO), Grey wolf optimization (GWO) and Salp swarm algorithm (SSA) methods. [ABSTRACT FROM AUTHOR]

The tracking control of a non-linear fractional-order system (FOS) is highly tedious since cumulative approximation errors are encountered during the control process. Hence, to cope with that problem, several controllers have been adopted previously, such as backstepping controllers, sliding mode controllers, dynamic surface controllers, etc. These controllers have successfully reduced the approximation errors in the integer order non-linear system. However, the performance of those effective controllers in fractional-order non-linear systems is evaluated in this paper. The controllers such as the backstepping controller, sliding mode controller, dynamic surface controller and fuzzy dynamic surface controller are examined on FOS to verify the stability of control systems. As a result, the backstepping controller has performed better than other controllers in the case of actuator errors but still has the problem of the increased number of derivative terms and greater complexity in repeated calculations. The tracking error of the backstepping controller has been reduced to 0.0358 with 1.58 s of response time. [ABSTRACT FROM AUTHOR]

Abstract HVE-400 ion implanter is special ion implantation equipment for semiconductor materials boron and phosphorus doping. The ion source and extraction deflection system are at high voltage platform, while the corresponding control system is at ground voltage position. The control signals and measurement signals of various parameters at the high-voltage end need to be transmitted between ground voltage and high voltage through optical fibers to isolate high voltage. Upgrading is carried out due to the aging of the optical fiber transmission control and monitoring system, which cannot work stably. The transformation replaces the original distributed single-point control method with an advanced distributed centralized control method, and integrates all control and monitoring functions into an industrial control computer for digital operation and display. In the computer software, two kinds of automatic calculation of ion mass number are designed. After upgrading, the implanter high-voltage platform control and monitoring system features digitalization, centralized control, high reliability, strong anti-interference, fast communication speed, and easy operation.

HVE-400 ion implanter is special ion implantation equipment for semiconductor materials boron and phosphorus doping. The ion source and extraction deflection system are at high voltage platform, while the corresponding control system is at ground voltage position. The control signals and measurement signals of various parameters at the high-voltage end need to be transmitted between ground voltage and high voltage through optical fibers to isolate high voltage. Upgrading is carried out due to the aging of the optical fiber transmission control and monitoring system, which cannot work stably. The transformation replaces the original distributed single-point control method with an advanced distributed centralized control method, and integrates all control and monitoring functions into an industrial control computer for digital operation and display. In the computer software, two kinds of automatic calculation of ion mass number are designed. After upgrading, the implanter high-voltage platform control and monitoring system features digitalization, centralized control, high reliability, strong anti-interference, fast communication speed, and easy operation. [ABSTRACT FROM AUTHOR]

Abstract This paper deals with the mitigation of sub‐synchronous resonance (SSR) in doubly‐fed induction generator (DFIG)‐based wind farms using a sub‐synchronous resonance damping controller (SSRDC). The performance of the SSRDC depends on its input control signal and the location of its output control signals. Hence, this paper presents an algorithm to select the best location for applying the SSRDC. The DFIG parameters are used as the inputs of this algorithm. Also, the participation factors analysis is employed as this algorithm's main core. The output of this algorithm determines that the control signal of SSRDC can be applied either in the grid‐side converter (GSC) and/or in the rotor‐side converter (RSC). The best input location in the GSC is the DC‐link voltage and the best input location in the RSC is the q‐component of the rotor voltage. The accuracy of this algorithm was evaluated by investigating the effect of various input signal locations on the SSR using the eigenvalue analysis. This analysis indicated that the dc‐link voltage and the q‐components of the rotor voltage are the most effective signals on the sub‐synchronous oscillatory modes. Moreover, this paper introduces a new SSRDC using these two signals. The performance of this controller is validated through the eigenvalue analysis and a time domain simulation.

This paper deals with the mitigation of sub‐synchronous resonance (SSR) in doubly‐fed induction generator (DFIG)‐based wind farms using a sub‐synchronous resonance damping controller (SSRDC). The performance of the SSRDC depends on its input control signal and the location of its output control signals. Hence, this paper presents an algorithm to select the best location for applying the SSRDC. The DFIG parameters are used as the inputs of this algorithm. Also, the participation factors analysis is employed as this algorithm's main core. The output of this algorithm determines that the control signal of SSRDC can be applied either in the grid‐side converter (GSC) and/or in the rotor‐side converter (RSC). The best input location in the GSC is the DC‐link voltage and the best input location in the RSC is the q‐component of the rotor voltage. The accuracy of this algorithm was evaluated by investigating the effect of various input signal locations on the SSR using the eigenvalue analysis. This analysis indicated that the dc‐link voltage and the q‐components of the rotor voltage are the most effective signals on the sub‐synchronous oscillatory modes. Moreover, this paper introduces a new SSRDC using these two signals. The performance of this controller is validated through the eigenvalue analysis and a time domain simulation. [ABSTRACT FROM AUTHOR]

Issues related to using an automated control system for the operation of thermocompression equipment are discussed. The automated system under consideration is designed to control metal flow during the formation of geometrically complex products under the conditions of isothermal and superplastic forging. The identified problems include noncompliance with the temperature and rate parameters of the forging process, the inertia of the system, the complexity of reconfiguring the system when manufacturing parts from different materials or when switching to the use of other equipment. To overcome the inertia of the system, it is proposed to use, on the one hand, digital extrapolation algorithms based on an experimental recording of the motion of operating elements under the influence of electric current, depending on its strength and duration of exposure, and, on the other, pulse–width modulation to control the current supply to the heating elements. Changes were introduced to modernize the hardware of the automated control system of a thermocompression unit and the TermoControl 3.1 Alpha software package. As a result, the updated version TermoControl 3.7 Alpha was created to ensure a higher accuracy in maintaining the temperature and rate parameters of the forging process. The deviation from the specified heating parameters (error) did not exceed 2–4°C; the error of the deformation rate comprised about 0.1·10–3 mm/s. An extensive database of heating, holding, and cooling modes was compiled, based on the results of predicting the operation of various thermocompression equipment types and models. The use of the developed automated control system allows the deviations from the specified modes of heating and deformation to range within the limits of statistical error. [ABSTRACT FROM AUTHOR]

This article proposes a hybrid approach for power flow management and power quality (PQ) improvement in smart grid (SG) system. The proposed methodology is designed into two phases, power flow management is the first stage and power quality improvement is the second stage of the system. The key purpose of the proposed method is "to regulate that power flow depends on variation of source and load side parameters deliver the highest PQ." The initial phase of power flow management is executed by using Improved Binary Sailfish Optimizer (IBSFO) approach. The control signal is recognized by the IBSFO approach against active and reactive power variation. The second phase of power quality enhancement is implemented by K2ORBFNN, which is the combination of Kho‐Kho optimization (KKO) and Radial Basis Function Neural Network (RBFNN). The gain parameter of the proportional integral (PI) controller is tuned based on load current, DC link, and voltage sources using K2ORBFNN approach. The prediction of optimal control signal minimizes the error which is obtained by RBFNN approach. The proposed method is utilized to attain compensating non‐linear load current harmonics, compensating reactive load power requirement, compensating unbalanced load current with neutral current. Finally, the performance of proposed system is executed in the MATLAB platform and performance is compared with existing techniques. The efficiency under the trails of 100, 200, 500, and 1000 attains 99.1673%, 99.4567%, 99.8402%, and 99.9879%. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Specific loci of the dACC responded to cues paired with fear and cognitive effort. • When combined, two different aversive cues produced additive activity in the dACC. • The dACC switched its effective connectivity depending on aversive contexts. Some studies have argued that the dorsal anterior cingulate cortex (dACC) is generally activated in response to aversive information, including pain, negative affect, and cognitive conflict. Other studies have claimed that the dACC has subdivisions, and each division has a specific function. By manipulating emotionally and cognitively aversive cues, the present study determined whether the dACC is generally responsive to aversiveness or it has subdivisions for specific forms of aversiveness. Conjunction functional magnetic resonance imaging (fMRI) analysis showed that emotionally and cognitively aversive cues activated the same portion of the dACC. When these cues were contiguously presented, the region demonstrated additive activity, further supporting the overlapping representation of the two different forms of aversiveness in the dACC. Additional effective connectivity analysis showed that the dACC was co-activated with different brain regions depending on the cue type, characterizing its behavioral control mechanism. Complementary multivariate analyses showed that the reaction time was negatively correlated with the activity of the dACC and that the activity of the dACC under the emotional cue was predicted by the individual state anxiety score but not under the cognitive cue. We also found that the superior part of the dACC was uniquely activated in response to cognitively aversive cues, partially supporting the functional segregation account. Collectively, our results provide evidence that the specific locus of the dACC is generally responsive to distinctive motivational information, whereas the other loci may have segregated functions. Discussion includes recent neurocomputational theories that seem to satisfactorily account for the present results. [ABSTRACT FROM AUTHOR]

ObjectivesAn active control T-foil can effectively improve the longitudinal anti-rolling motion of the ship, but there is still no conclusion on what control strategy has the best anti-rolling effect. So the paper has studied and analyzed the active control strategies of the T-foil.Methods The paper uses the slender body theory to calculate the longitudinal motion of Wigley III in regular waves of different wavelengths. Then, the damping effect of the ship with the passive and active T-foil is calculated and analyzed under the same speed and wave conditions. Results The results show that the passive control T-foil has a good anti-rolling effect in the resonance region, however, the anti-rolling effect in the long and short wave region is relatively limited. The control with a pitch velocity signal is very effective in reducing the pitch motion and the acceleration of bow motion, but it increases the heave motion in the longwave area. The anti-rolling effect of bow motion velocity signal on-pitch motion and acceleration of bow motion is 10%-20% higher than that of a pitch velocity signal, and there is no reduction effect on heave motion.Conclusions For the active control strategies of T-foil, the bow motion velocity signal can achieve a better anti-rolling effect by comprehensively considering both pitch and heave motions.

This research analyzes the asymmetric control strategies in multilevel inverters, including asymmetric techniques in space vector modulation of power converters. Modulation parameters such as reference voltage vector (Vref), switching time, and duty cycle are derived in the three-dimensional spatial vector geometry formulation. Asymmetric space vector pulse width modulation (SVPWM) is unique in specifying modulation parameters, has unequal tetrahedron patterns, accompanied by application examples for the upper and lower sector pairs of a tetrahedron. The combination of the switch in the form of an inclined cylinder produces twelve pairs of asymmetric tetrahedrons where the voltage vector positions are in the other twenty-four tetrahedrons. The calculation shows processing dead-time in switching, which is used for current compensation in three-phase power converters. [ABSTRACT FROM AUTHOR]

We have studied and obtained logic gates through three-core nonlinear directional couplers and dual-core nonlinear directional couplers operating in continuous wave mode in which the laser signal has the same wavelength. In symmetrical three-core nonlinear directional couplers with its identical cores in a planar arrangement was studied using a control pulse applied to the first core. In dual core the structure was the asymmetric two core switching process was held in symmetrical triangular fiber couplers and three-core nonlinear directional couplers using the coupled mode of the nonlinear Schrodinger equation. The logic gates, AND, OR and NXOR were generated from the triangular three-core nonlinear directional couplers, while planar three-core nonlinear directional couplers produced logic gates AND, NAND, OR and XOR. For this two basic modes were considered. The first triangular structure with three symmetrical core were considered from an equilateral triangle and used a control signal applied to the first core. In the second model the symmetric cross structure with three cores in a parallel equidistant arrangement. We have obtained optical logic gates in a fiber coupler doped with erbium, leaded the resonant non linearity to change the refractive index which helped to reduce the device switching energy threshold. [ABSTRACT FROM AUTHOR]

In the work problems related to control of precision piezoelectric actuator devices, piezo actuators in particular, are discussed. Multichannel system of control of piezo actuators is presented. Possibility of using the said control system to control the shape of the space-based large transformed antenna is discussed.

This paper presents a method and results, which studies influencesofthefuelflowmodeonthepressureoscillationinthevolumesofthe accumulator fuel system. The fuel is supplied through nozzle holes into a constant volume chamber, which is installed a drain orifice for fuel discharge into the low- pressure line. Results show that the increase in the base pressure value of the fuel accumulator leads to the rise in the slope of the leading edge of the differential characteristics and the maximum dQ/dt value changes closer to the beginning moment of the fuel injection process. At the same time, the controlpressurevalueisasignificantparameterthatgreatlyinfluencestheshapeoftheinjectioncharacteristic. In addition, when using the drain orifices with different diameters, received values and differential characteristics vary during the fuel supply process. The differential characteristics of the study are the basis for implementing fuel injection control solutions. [ABSTRACT FROM AUTHOR]

Aiming at the problem that the current image caption approaches can only describe the image with a black box architecture, which is difficult to control from the outside. This paper creatively transformed the problem of image caption into the problem of seq2 seq, and achieved the effect of controllable generation of image caption. It designed an entity set or entity sequence composed of image regions as the control signal, under the guidance of the block sentry with entity block switching and the adaptive attention mechanism with visual sentry, regularly input the control signal into the double-layer long short term memory (LSTM), it guided the model to generate the corresponding image caption in a controllable way. In addition, baseline used cross-entropy loss to train and early stop the model, and introduced the idea of reinforcement learning to solve the problem that the optimization target in training was inconsistent with the index in evaluating the algorithm effect, so as to further optimize the model effect. The experimental results show that: on MSCOCO and Flickr30k datasets, the proposed algorithm achieves great results in generating controllable image caption, caption quality and diversity. [ABSTRACT FROM AUTHOR]

Introduction. Nowadays, communication systems are mostly digital. One of the tasks of automatic gain control in digital receivers is to maintain analog signals at the appropriately fixed level, which prevents saturation of the analogto-digital converter. Most numerical algorithms are based on floating point arithmetic, and digital automatic gain control is usually implemented using fixed-point arithmetic devices such as programmable logic chips and signal processors. As consequence of fixed-point arithmetic and hardware constraints usage, the out-put significant bits should be truncated correctly. Although many studies mention digital automatic gain control, its characteristics are not considered in detail in terms of the finite capacity of calculators.Objective. The purpose of the study is to analyze dynamic characteristics of digital automatic gain control implemented on a computer for operations on numbers with fixed-point.Materials and methods. Within the frames of the study in Matlab software was developed a mathematical model of digital automatic gain control. The model was implemented on a programmable logic chip.Results. The paper shows the difference in characteristics and features of the digital automatic gain control during operations on fixed-point numbers. The study provides the assessment of the effect of fixed-point signals on the stability of the digital automatic gain control and includes the analysis of causes of spurious oscillations of the control signal.Conclusion. The study proposes the algorithm for compensation of the control signal oscillations by means of correction of the reference level of the digital automatic gain control. Further is required to verify the proposed algorithm on real signals. The results of the study are relevant in development of digital receivers for communication systems of various purposes.

Despite the importance of the biodegradability of lignocellulose biomass, few studies have evaluated the lignocellulose biomass digestion kinetics and modeling of the process. Anaerobic digestion (AD) is a mature energy production technique in which lignocellulose biomass is converted into biogas. However, using different organic waste fractions in AD plants is challenging. In this study, lignocellulose biomass (corn stover hydrochar) obtained from hydrothermal carbonization at a temperature, residential time, and biomass/water ratio of 215 °C, 45 min, and 0.115, respectively, was added to the bioreactor as a substrate inoculated with food waste and cow dung to generate biogas. A state–space AD model containing one algebraic equation and two differential equations was constructed. All the parameters used in the model were dependent on the AD process conditions. An adaptive identifier system was developed to automatically estimate parameter values from input and output data. This made it possible to operate the system under different conditions. Daily cumulative biogas production was predicted using the model, and goodness-of-fit analysis indicated that the predicted biogas production values had accuracies of >90% during both model construction and validation. Future work will focus on the application of modeling predictive control into an AD system that would comprise both models and parameters estimation.

A high reliable inverter with photovoltaic systems improves the efficiency and longevity of the entire system. Recent research emphasises on developing new fault‐tolerant multilevel inverter (FTMLI) topologies. However, these topologies are not able to maintain rated voltage and power with a minimum switch count under switch fault conditions. This study proposes a new multilevel inverter with a reduced device count, which can handle both single switch fault and multi‐switch fault by preserving its rated voltage and power. Sine‐carrier‐based level‐shifted pulse‐width modulation is used to generate control signals. The carriers are reconfigured based on the type and location of the fault. The loss contribution of each switch is calculated in all modes of operation by considering variations in junction temperature using a Powersim (PSIM) thermal model tool. This study helps to choose an appropriate heat sink for the switches. The reliability density function is calculated using a Markov chain model. A comparative study is presented to assess the notable benefits of the proposed topology over other existing similar topologies. The experimental results from the laboratory prototype are provided to verify the efficacy and practicality of the proposed FTMLI configuration. [ABSTRACT FROM AUTHOR]

The control of self‐driving cars has received growing attention recently. Although existing research shows promising results in the vehicle control using video from a monocular dash camera, there has been very limited work on directly learning vehicle control from motion‐based cues. Such cues are powerful features for visual representations, as they encode the per‐pixel movement between two consecutive images, allowing a system to effectively map the features into the control signal. The authors propose a new framework that exploits the use of a motion‐based feature known as optical flow extracted from the dash camera and demonstrates that such a feature is effective in significantly improving the accuracy of the control signals. The proposed framework involves two main components. The flow predictor, as a self‐supervised deep network, models the underlying scene structure from consecutive frames and generates the optical flow. The controller, as a supervised multi‐task deep network, predicts both steer angle and speed. The authors demonstrate that the proposed framework using the optical flow features can effectively predict control signals from a dash camera video. Using the Cityscapes data set, the authors validate that the system prediction has errors as low as 0.0130 rad/s on steer angle and 0.0615 m/s on speed, outperforming existing research. [ABSTRACT FROM AUTHOR]

Objective: The main objective of the proposed control scheme is the elimination of harmonics present in the output with minimum injection. Methods: The proposed hybrid control scheme is the fusion of both the Cuttlefish Algorithm (CFA) and Artificial Feeding Birds (AFB). Results: The proposed method is implemented in Matlab Simulink working platform. The results are carried out with different case studies and the performances of proposed technique are compared with various existing techniques. In this dissertation, the obtained harmonic current ratio factor (HCRF) for the proposed technique is 7.3432%. Conclusions: The results are carried out with different case studies and the performances of proposed technique are compared with various existing techniques. From the result outcomes, it is proved that the proposed technique stands to be remarkable with high accuracy, high response, and minimum total harmonic distortion (THD) for source and load current. It responds excellently under all the load conditions. [ABSTRACT FROM AUTHOR]

In this study, an adaptive fractional‐order non‐singular fast terminal sliding mode (FO‐NFTSM) scheme based on time delay estimation (TDE) is proposed for the control of robotic manipulators. A new FO‐NFTSM surface with a continuous TSM‐type switch item is designed to ensure good performance, such as fast finite‐time convergence, high precision and being non‐singular. The chattering problem is solved by introducing a saturation function into the control signal. The TDE element is used to estimate the robot's unknown dynamic parameters and external disturbances. The Lyapunov stability theory is used to prove the finite‐time stability of the control system. The proposed control algorithm is applied to a two‐link robotic manipulator and the comparative results verify the effectiveness and superiority of the proposed control approach in comparison with existing control methods. [ABSTRACT FROM AUTHOR]

This study describes an iterative learning approach to the active control of machinery noise with high autocorrelation properties. In contrast to typical active noise control solutions, which work by adapting the transfer function of the controller, in the iterative learning control one adapts the control signal itself. Special care was taken to develop a generic solution that can handle different sorts of secondary path models including very long and non‐minimum phase finite impulse response filters. To achieve that, the authors used spectral factorisation and exploit the fact that, for non‐minimum phase systems, a stable inverse can be constructed if the causality constraint is relaxed and later restored by taking advantage of the periodicity of the attenuated signal. The resulting controller can be efficiently implemented on a sample‐to‐sample calculation basis. The behaviour and the performance of the proposed scheme are studied using computer simulations and real‐world experiments on noises from an electric transformer and functional magnetic resonance imaging device. The proposed solution was also compared to normalised feedforward filtered‐X least mean squares algorithm and performed much better in terms of attenuation, convergence, and robustness. [ABSTRACT FROM AUTHOR]

This study addresses the handover management issue for Device-to-Device communication in fifth-generation (5G) networks. The Third Generation Partnership Project (3GPP) drafted a standard for proximity services (ProSe), also named device-to-device (D2D) communication, which is a promising technology in offering higher throughput and lower latency services to end users. Handover is an essential issue in wireless mobile networks due to the mobility of user equipment (UE). Specifically, we need to transfer an ongoing connection from an old E-UTRAN Node B (eNB) to a new one, so that the UE can retain its connectivity. In the data plane, both parties of a D2D pair can communicate directly with each other without the involvement of the base station. However, in the control plane, devices must be connected to the eNB for tasks such as power control and resource allocation. In the current standard of handover scheme, the number of unnecessary handovers would be increased by the effect of shadowing fading on two devices. More important, the handover mechanism for D2D pairs is not standardized yet. LTE-A only considers the handover procedure of a single user. Therefore, when a D2D pair moves across cell boundaries, the control channels of the two UEs may connect to different base stations and result in increased latency due to the exchange of D2D related control messages. Hence, we propose a handover management scheme for D2D communication to let both parties of a D2D pair handover to the same destination eNB at the same time. By doing so, the number of unnecessary handovers, as well as the handover latency, can be reduced. In the proposed method, we predict the destination eNB of D2D users based on their movements and the received signal characteristics. Subsequently, we make a handover decision for each D2D pair by jointly factoring in the signal quality and connection stability. Expected improvement can be attained, as revealed in the simulation. Unnecessary handover can be avoided. Consequently, both UEs of a D2D pair reside in the same cell and, therefore, result in increased throughput and decreased delay. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai University / Shanghai Daxue Xuebao is the property of Journal of Shanghai University (Natural Sciences) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A method for calculating the frequency sweep law of a vibration source is proposed and substantiated, which yields a flat spectrum of the correlogram of the target wave, regardless of natural amplitude–frequency distortions introduced by the medium and source. Such a spectrum serves as the main prerequisite for achieving maximum resolution of closely spaced wave pulses in the resulting seismogram. The methodology includes test sounding of a typical seismic geological object with any linear sweep signal in the desired frequency range, separation and spectral analysis of the vibrogram of the target wave, splitting of the resulting spectrum into many narrow frequency intervals, and calculating for each of the intervals its own partial linear sweep. Construction of a continuous sequence of these partial sweeps is the final operation in synthesizing an adaptive nonlinear (piecewise linear) sweep signal. In this study, the necessary conditions are found and formulated that ensure correctness of the coupling procedure for partial sweeps. [ABSTRACT FROM AUTHOR]

Decentralised droop‐like control method is the most favourable control system for power converter‐based microgrids (MGs). In conventional V–Q droop loops, reactive power sharing is used as a means of voltage regulation to prevent currents from circulating among distributed generation units. However, since the voltage is not a global variable, reactive power sharing is not implemented precisely, and thus converters may be exposed to overcurrent conditions and the stability of the MGs is put at risk. Besides, the droop‐like reactive power sharing causes voltage deviations and power quality issues. This study proposes a novel control method which is able to implement accurate reactive power sharing and voltage regulation to its nominal band in a networked MG. Both the control targets are achieved, fast and simultaneously, by only one control signal. So the requirement of a secondary controller for voltage restoration is obviated. A novel power flow‐based method is proposed to estimate the voltage at the MG main bus, which is adopted as a common variable, thus making the proposed method decentralised. The presented method is fast, effective and applicable to networked MGs with arbitrary topology. Simulation results prove the effectiveness and superiority of the proposed method over existing methods. [ABSTRACT FROM AUTHOR]

This study presents a Laguerre‐based stochastic economic predictive functional control (L‐SEPFC) method for real‐time power dispatch of balance responsible parties (BRPs). In this regard, at the control layer, an L‐SEPFC method operates on the energy time scale and optimises the expected economic performance of the BRP. Calculated set points in this layer are average power injection of controllable generators, as well as known disturbance of prediction wind generation. The novel L‐SEPFC scheme is able to cope with the wind uncertainty occurring in the real‐time operation of BRPs. Furthermore, the proposed algorithm is able to take into account the technical constraints of generators and transmission line constraints of the power network. Due to the parameterisation of the future control signal based on the Laguerre function, the proposed method is faster than the nominal predictive algorithms. Simulations on an IEEE 118‐bus test system with proposed method shows improvements inability to track reference production, economic performance, imbalance energy and computational burden with respect to nominal predictive controllers. [ABSTRACT FROM AUTHOR]

This study presents the quadratic boost converter (QBC) as a power electronic interface between the fuel cell (FC) stack and the DC bus of the FC vehicle (FCV). QBC provides the high voltage gain to interface the low voltage, high current and non‐linear FC stack to higher voltage DC bus of the proposed architecture. The output voltage of FC is variable and is a function of cell chemistry, load variations and atmospheric conditions. Therefore, a genetic algorithm assisted fixed frequency sliding mode controller (SMC) based two‐loop control strategy is proposed and developed in this study. The accuracy of the control signal generated by the SMC depends on the accuracy of reference current generation. Therefore, genetic algorithm tuned proportional–integral controller is proposed to generate the ripple‐free reference current generation which follows the load‐side or source‐side variations. Further, a control algorithm is integrated with SMC which uses the design constants such that the chattering amplitude is suppressed and generates the control signal with fixed frequency. Consequently, the dynamic performance of the proposed controller is compared in terms of the tracking error, control effort and sliding surface error. The extensive studies are carried out under different dynamic conditions to analyse the robustness of the proposed controller for QBC‐based FCV. [ABSTRACT FROM AUTHOR]

A modified lattice hydrodynamic model is proposed, in which the impact of strong wind and the optimal estimation of flux difference integral are simultaneously analyzed. Based on the control theory, the stability condition is acquired through linear analysis. The modified Korteweg-de Vries (mKdV) equation is derived via nonlinear analysis, in order to express a description of the evolution of density waves. Then, numerical simulation is conducted. From the simulation results, strong wind can largely influence the traffic flow stability. The stronger the wind becomes, the more stable the traffic flow is, to some extent. Similarly, the optimal estimation of flux difference integral also contributes to stabilizing traffic flow. The simulation results show no difference compared with the theoretical findings. In conclusion, the new model is able to make the traffic flow more stable.

Internet of Things (IoT) technologies have been broadly applied in smart grid for monitoring physical or environmental conditions. Especially, state estimation is an important IoT-based application in smart grid, which is used in system monitoring to get the best estimate of the power grid state through an analysis of the meter measurements and power system topologies. However, false data injection attack (FDIA) is a severe threat to state estimation, which is known for the difficulty of detection. In this paper, we propose an efficient detection scheme against FDIA. First, two parameters that reflect the physical property of smart grid are investigated. One parameter is the control signal from the controller to the static Var compensator (CSSVC). A large CSSVC indicates there exists the intense voltage fluctuation. The other parameter is the quantitative node voltage stability index (NVSI). A larger NVSI indicates a higher vulnerability level. Second, according to the values of the CSSVC and NVSI, an optimized clustering algorithm is proposed to distribute the potential vulnerable nodes into several classes. Finally, based on these classes, a detection method is proposed for the real-time detection of the FDIA. The simulation results show that the proposed scheme can detect the FDIA effectively.

In order to smooth the system frequency disturbances caused by wind power fluctuation, this study proposes a novel load frequency control (LFC) strategy based on model predictive control (MPC) to regulate the system frequency. The proposed strategy mainly aims to improve the system frequency responses by considering the dynamics of wind turbine (WT) and forecasting the output power of WT. First, the frequency response model (FRM) of system including the power system LFC and WT is established. Second, through discretisation of the FRM, a predictive model of system is obtained. Then, system state and response in the next predictive period are forecasted by the predictive model. After obtaining the prediction information, the control signal of system is optimised for improving system frequency response. On this basis, a novel MPC‐based LFC strategy is proposed based on the predictive model and the optimisation of control sequence. With the information of wind speed, this control strategy is able to forecast the system states and responses easily and adjust the control signal according to wind power fluctuation. Finally, numerical simulations are demonstrated to visualise the effectiveness and feasibility of the proposed MPC‐based LFC strategy and its advantages over existing methods. [ABSTRACT FROM AUTHOR]

The rapidly increasing penetration of renewable energies has introduced severe challenges to power system frequency controls due to the highly intermittent and uncertain power output of renewable energies. This study proposes a proactive frequency control method to control traditional synchronous generators in advance in anticipation of sudden power fluctuation. Therefore, the frequency deviations can be well mitigated by such early‐acted control signal. In order to obtain this new control reference, an ensemble‐forecasting model based on the extreme learning machine algorithm is designed to predict ultra‐short‐term power fluctuations, which serves as an extra signal for automatic generation control. The proposed method was verified on an equivalent model of the Singapore power system with various types of generations and loads. The simulation results clearly demonstrate the accuracy of the forecasting model and the advantages of the proposed control method. The proposed method can also reduce the frequency charging/discharging of energy storage systems, which can effectively extend their lifetime. [ABSTRACT FROM AUTHOR]

One of the major issues in the operation of an islanded microgrid is the frequency deviations caused by the variation of power production coming from non‐dispatchable renewable energy sources. Using an appropriate control system may allow the system to deal with the frequency deviation and allow the system frequency to be restored to its rated value. A wide‐area system frequency controller sends a control signal to each of the dispatchable generating sources to enforce the frequency control by using communication channels. However, the communication channels are susceptible to the time delays, which affect the performance of the frequency control system and potentially the system security. Also, the system parameters are uncertain due to the error in the modelling, variation in network topology, generations, loads etc. This study proposes a robust proportional and integral (PI) system frequency controller based on Kharitonov theorem (KT) considering the time delay of the communication system and the system parametric uncertainties. Simulation results demonstrate that the KT‐based controller model has enhanced robustness compared to the conventional approaches of controller design. [ABSTRACT FROM AUTHOR]

An extended lattice hydrodynamic model is presented by considering the historical relative flux in integral form and flux change rate. The flux change rate can be regarded as the control signal. Control method is applied to the linear stability analysis and the stability condition of the model is obtained. In addition, energy consumption is also explored. To prove the theoretical findings, numerical simulations are carried out in this paper. Simulation results show that the historical relative flux can worsen the traffic flow stability and increase the energy consumption. The control signal plays a significant role in stabilizing the traffic flow and leading to a lower energy consumption. The simulation results are found consistent with the theoretical results. • An extended lattice hydrodynamic model considering the relative flux and delayed-feedback control is proposed. • Applying the control theory, the new model's linear stability is obtained. • The energy consumption for this new model are studied. [ABSTRACT FROM AUTHOR]

This study addresses the handover management issue for Device-to-Device communication in fifth-generation (5G) networks. The Third Generation Partnership Project (3GPP) drafted a standard for proximity services (ProSe), also named device-to-device (D2D) communication, which is a promising technology in offering higher throughput and lower latency services to end users. Handover is an essential issue in wireless mobile networks due to the mobility of user equipment (UE). Specifically, we need to transfer an ongoing connection from an old E-UTRAN Node B (eNB) to a new one, so that the UE can retain its connectivity. In the data plane, both parties of a D2D pair can communicate directly with each other without the involvement of the base station. However, in the control plane, devices must be connected to the eNB for tasks such as power control and resource allocation. In the current standard of handover scheme, the number of unnecessary handovers would be increased by the effect of shadowing fading on two devices. More important, the handover mechanism for D2D pairs is not standardized yet. LTE-A only considers the handover procedure of a single user. Therefore, when a D2D pair moves across cell boundaries, the control channels of the two UEs may connect to different base stations and result in increased latency due to the exchange of D2D related control messages. Hence, we propose a handover management scheme for D2D communication to let both parties of a D2D pair handover to the same destination eNB at the same time. By doing so, the number of unnecessary handovers, as well as the handover latency, can be reduced. In the proposed method, we predict the destination eNB of D2D users based on their movements and the received signal characteristics. Subsequently, we make a handover decision for each D2D pair by jointly factoring in the signal quality and connection stability. Expected improvement can be attained, as revealed in the simulation. Unnecessary handover can be avoided. Consequently, both UEs of a D2D pair reside in the same cell and, therefore, result in increased throughput and decreased delay.