Alka Adya

Power Quality Enhancement with DSTATCOM for Small Isolated Alternator feeding Distribution System

This paper focuses on power quality improvement with DSTATCOM on a small, isolated 42.5 kVA alternator feeding a three-phase, three-wire distribution system. Some power quality aspects like power-factor correction, voltage regulation and load balancing of linear load are discussed and implemented using DSTATCOM. DSTATCOM is realized using a three leg IGBT based PWM-VSI bridge having a DC bus capacitor. A hysteresis rule based carrier-less PWM current controller is used to derive gating pulses for the IGBT switches. The models are developed and simulated in MATLAB using Simulink and Power System Blockset (PSB) toolboxes. It is observed that DSTATCOM is effective in compensating reactive power and improving the power quality of the distribution system

Modeling, Design and Analysis of Different Controllers for DSTATCOM

This paper deals with different control strategies for DSTATCOM (distribution static compensator) for power quality improvement for a three-phase, three-wire distribution system. A three-leg voltage source inverter (VSI) configuration with a dc bus capacitor is employed as DSTATCOM. The hysteresis as well as PWM current controllers are designed, analyzed and compared for PI controller and sliding mode controller. The capability of the DSTATCOM is demonstrated through results obtained using MATLAB and Simulink based developed model of the DSTATCOM system. The performance of the DSTATCOM acting as a shunt compensator is found satisfactory under varied load perturbations.

Application of DSTATCOM for Mitigation of Voltage Sag for Motor Loads in Isolated Distribution Systems

This paper deals with one of the potential applications of distribution static compensator (DSTATCOM) to industrial systems for mitigation of voltage dip problem. The dip in voltage is generally encountered during the starting of an induction motor. Isolated distribution systems are comparatively not as stiff as grid systems; so large starting currents and objectionable voltage drop during starting of an induction motor could be critical for the entire system. DSTATCOM is one effective solution for isolated power systems facing such power quality problems. The model of DSTATCOM connected in shunt configuration to such an isolated system (3phase, 42.5 kVA alternator) feeding dynamic motor loads is developed using Simulink and PSB of MATLAB software. Simulated results demonstrate that DSTATCOM can be a considered as a viable solution for solving such voltage dip problems

Analysis, simulation and control of DSTATCOM in three-phase, four-wire isolated distribution systems

This paper deals with the performance of distribution static synchronous compensator (DSTATCOM) connected to an alternator of 42.5 kVA rating feeding four-wire linear loads. Simulation of DSTATCOM connected such weak system is carried out using standard MATLAB environment and power system toolbox. Results are simulated for linear resistive-inductive lagging power-factor loads for power factor correction, voltage regulation and load balancing for improving the power quality of the system isolated from the power grid

DSTATCOM for power quality improvement in a four-wire electric distribution system

This paper deals with the simulation of a Distribution Static Compensator (DSTATCOM) for power quality improvement in a four-wire electric distribution system. A three-phase Insulated Gate Bipolar Transistor (IGBT)-based Current-Controlled Voltage Source Inverter (CC-VSI) with a DC bus capacitor is used as a DSTATCOM. The DSTATCOM improves the supply power factor, eliminates harmonics, provides load balancing and improves the load terminal voltage at the Point of Common Coupling (PCC). The DC bus voltage of the DSTATCOM and three-phase voltages at PCC are used as feedback signals for PI controllers. The control algorithm of the DSTATCOM provides three-phase reference supply currents. A carrierless hysteresis current controller is employed over the reference and sensed supply currents to generate gating pulses for the IGBTs of DSTATCOM. Simulation is carried out in the MATLAB environment using Simulink and Power System (PSB) toolboxes. Results are presented and discussed, which demonstrate power quality improvement capability of DSTATCOM system.

MATLAB-based modelling of Distribution STATCOM applied to isolated power system

This paper presents the modelling of Distribution Static Compensator (D-STATCOM) used in isolated power systems. The model of D-STATCOM is developed using Power System Block-set (PSB) and Simulink toolboxes of standard MATLAB software. Two proportional integral PI controllers are used to control DC bus voltage and AC bus voltage regulation at the point of common coupling. Results are presented for D-STATCOM used in an isolated distribution system fed from an alternator. It is observed from results that D-STATCOM is able to improve power factor, provide voltage regulation, balance the loads and reduce harmonics.

Modelling of DSTATCOM for distribution system

This paper deals with the simulation of distribution static synchronous compensator (DSTATCOM) for improving power quality of a distribution system feeding linear as well as non-linear loads. Nowadays, there are an increasing number of non-linear loads which inject harmonics into the system. A three-phase insulated gate bipolar transistor- (IGBT-)based current controlled voltage source inverter with a DC bus capacitor known as a DSTATCOM is used for power factor correction, harmonic compensation and for providing required reactive power to the load. A model of DSTATCOM connected to a power distribution system feeding linear and non-linear loads (diode bridge rectifier with R and R-C) is developed for predicting the behaviour of system under transient conditions. Simulation is carried out in standard MATLAB environment using Simulink and power system blockset toolboxes. Control algorithm is made flexible so that it can correct supply power factor, eliminate harmonics and provide load balancing. The control algorithm utilises one closed loop PI controller for regulating the DC link voltage of DSTATCOM and second PI controller for regulating the AC voltage at point of common coupling. Results are presented for a variety of linear and non-linear balanced as well as unbalanced loads, which demonstrate power factor correction, voltage regulation, harmonic elimination and load balancing capabilities of DSTATCOM.

Design, analysis and control of compensators for distribution power systems

This paper deals with the analysis, design and control of Distribution Static Compensator (DSTATCOM) for power quality improvement in an AC distribution system. Various design criteria are considered for the design of DSTATCOM for a variety of possible functions such as voltage regulation, power factor correction and load balancing. Conventional AC power capacitors are considered in conjunction with DSTATCOM for reducing the rating of DSTATCOM. The design of DSTATCOM is carried out and the ratings of its DC bus capacitor, AC filter inductor, current and voltage ratings of solid-state devices are determined along with AC capacitors to reduce the rating of DSTATCOM.