Sliding mode control of static shunt compensator

This paper deals with the implementation of sliding mode control (SMC) strategy for a four-leg voltage supply converter (VSC) based distribution static synchronous compensator (DSTATCOM) for power quality improvement in a three phase four-wire power distribution network. The main advantages of using the SMC in a DSTATCOM is the DC link voltage profile during the transient conditions is improved to less than 2% that of nominal DC link voltage and its second advantage is that the reference currents are estimated without sensing the load currents, which reduces current sensors. The DSTATCOM is modeled using Simulink and SimPowerSystem (SPS) toolboxes of MATLAB. The SMC algorithm is successfully tested and implemented on the laboratory developed prototype and it is satisfactorily verified for mitigation of power quality problems such as harmonics elimination, reactive power compensation, neutral current compensation and load balancing under nonlinear/linear loads.