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This paper presents Distribution Static Compensator (DSTATCOM) for compensation of unbalanced nonlinear load with dq 0 current controller (using proportional integrator and harmonic compensation regulators) and Sinusoidal Pulse Width Modulation (SPWM) switching. The dq 0 current controller is implemented in Synchronous Reference Frame (SRF) rotating at fundamental frequency and consists of Harmonic Compensation (HC) regulator (realized by sum of Sinusoidal Signal Integrators (SSI)) in parallel to Proportional Integrator (PI) regulator. The SSI provides high gain to specified tuned harmonic frequency and helps in improving filter current tracking performance for harmonic load current compensation. Each SSI in fundamental rotating dq 0 reference frame can simultaneously compensate for two load current harmonics and thereby reducing the computational effort compared to SSI in stationary reference frame. Neutral current compensation, which is required for compensating unbalance in load, is carried out through 0-axis controller. SPWM switching strategy results in switching of inverter switches at constant frequency. This will simplify the design of inverter output filter (L/LC), reduces stress on switches and switching noise. Simulation studies of DSTATCOM load compensation using dq 0 current controller with interface L and LC filters is carried out in Matlab/Simulink and the corresponding results are presented. Experimental studies are carried out on three phase DSTATCOM prototype using dSPACE 1104 with Matlab Real Time Interface (RTI). [ABSTRACT FROM AUTHOR]

Various load compensation schemes proposed in literature assume that voltage source at point of common coupling (PCC) is stiff. In practice, however, the load is remote from a distribution substation and is supplied by a feeder. In the presence of feeder impedance, the PWM inverter switchings distort both the PCC voltage and the source currents. In this paper load compensation with such a non-stiff source is considered. A switching control of the voltage source inverter (VSI) based on state feedback is used for load compensation with non-stiff source. The design of the state feedback controller requires careful considerations in choosing a gain matrix and in the generation of reference quantities. These aspects are considered in this paper. Detailed simulation and experimental results are given to support the control design. [Copyright &y& Elsevier]

Abstract: This paper proposes the effective utilization of unified power quality conditioner (UPQC) for interconnecting the PV modules to the grid using power angle control (PAC) method. A shunt active power filter (APF) is used to evacuate the power from the photovoltaic module in addition to compensating the current harmonics, load unbalance and reactive power. To accomplish this the series APF in the UPQC is used for supplying a part or whole reactive power required by the load in addition to compensating the sag, swell, supply voltage unbalance and distortions. This is made possible by controlling the phase angle and magnitude of series injected voltage called power angle control method. The reactive power and voltage compensation technique introduces a phase shift between the load terminal voltage and source voltage. The transient due to sudden phase shift is minimized using step by step introduction of series compensation voltage. The proposed method effectively utilizes the shunt APF and series APF in the UPQC for interconnecting the PV module to the grid. The simulation results from MATLAB/SIMULINK are discussed to validate the developed method. [Copyright &y& Elsevier]