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In this paper, fast acting dc-link voltage-based energy management schemes are proposed for a hybrid energy storage system fed by solar photovoltaic (PV) energy. Using the proposed control schemes, quick fluctuations of load are supplied by the supercapacitors and the average load demand is controlled by the batteries. Fast dc-link voltage, effective energy management, and reduced current stress on battery are the main features achieved from the proposed control schemes. The effectiveness of the proposed control schemes are compared with the unified cascaded control. Small-signal control gains are formulated to design the voltage and current loops of the proposed energy management schemes. Detailed stability analysis is also presented to find the boundary values of compensator gains. In addition, a high-gain PV converter is proposed for extraction of maximum power from the solar panels. High voltage gain, reduced reverse recovery of diodes, and less duty cycle operation are the key features obtained from the proposed high-gain converter. The validity of the proposed energy management schemes with high-gain converter is verified by the detailed simulation and experimental studies. [ABSTRACT FROM AUTHOR]

This paper proposes a new algorithm to generate reference voltage for a distribution static compensator (DSTATCOM) operating in voltage-control mode. The proposed scheme exhibits several advantages compared to traditional voltage-controlled DSTATCOM where the reference voltage is arbitrarily taken as 1.0 p.u. The proposed scheme ensures that unity power factor (UPF) is achieved at the load terminal during nominal operation, which is not possible in the traditional method. Also, the compensator injects lower currents and, therefore, reduces losses in the feeder and voltage-source inverter. Further, a saving in the rating of DSTATCOM is achieved which increases its capacity to mitigate voltage sag. Nearly UPF is maintained, while regulating voltage at the load terminal, during load change. The state-space model of DSTATCOM is incorporated with the deadbeat predictive controller for fast load voltage regulation during voltage disturbances. With these features, this scheme allows DSTATCOM to tackle power-quality issues by providing power factor correction, harmonic elimination, load balancing, and voltage regulation based on the load requirement. Simulation and experimental results are presented to demonstrate the efficacy of the proposed algorithm. [ABSTRACT FROM AUTHOR]

This letter presents a dynamic hysteresis current control algorithm for a three-phase four-leg voltage-source inverter (VSI) topology. In order to improve the performance and life of the power switches of VSI, we require an optimized control technique that reduces its switching frequency. Proposed hysteresis current control method is a generalized control method that minimizes switching operations to compensate nonlinear load under both balanced and unbalanced supply voltages. It is shown that this control scheme is able to reduce the switching frequency by more than 50% compared to conventional hysteresis current control method and retain the quality of load compensation. The effectiveness of the proposed control scheme is illustrated through simulations using Power Systems Computer-Aided Design (PSCAD) 4.2.1. [ABSTRACT FROM AUTHOR]

Abstract-In this paper, an optimization-based control algorithm for the compensation of steady-state load under distorted supply voltages is presented. For balanced and sinusoidal supply voltages, load compensation using shunt active filter produces perfect harmonic cancellation (PHC) and unity power factor (UPF) source currents. However, when the supply voltages are distorted, compensation for PHC will not provide UPF, as the harmonics in the supply voltages are not utilized for delivering the average power. In the same way, to achieve UPF source currents, the compensated source currents should have the same harmonics, unbalance, shape, and be in phase with the respective supply voltages, thereby violating the perfect harmonic cancellation objective. Hence, there should be an optimal operation between these two important compensation characteristics. The optimization-based control algorithm presented in this paper gives the best power factor while satisfying the constraints such as total harmonic distortion limits and average power balance of source currents. It is also flexible to adopt different compensation characteristics based upon the supply voltage conditions. MATLAB and its optimization toolbox are used for simulation studies and solving the nonlinear optimization problem, respectively. The algorithm is validated by using a prototype of digital signal processor (TMS320F2812PGFA)-based shunt active power filter. Detailed experimental results are presented. [ABSTRACT FROM AUTHOR]