Mitigation of supply voltage disturbances with a load voltage-controlled inverter

The three-phase four-wire Voltage Controlled Voltage Source Inverter (VC-VSI) is proposed as a multi-function voltage compensator for supply voltage disturbances to improve the load voltage quality. The VC-VSI is positioned in series between the disturbed source and sensitive loads. The VC-VSI works to immediately control the load voltage instead of its output voltage. The control process takes place in the dq0 reference frame supported by a PI controller, since it is easy to build reference signals in the DC quantity. The VCVSI successfully creates a three-phase compensation voltage instantaneously so that the load voltage is sinusoidal, balanced and constant at the nominal value. The VC-VSI has been modeled and simulated in PSIM simulation program to verify the proposed concept. The test results showed that the VC-VSI performed well as the voltage disturbance compensator, by retaining insignificant mismatch of � 0.5% and low THD of the load voltage of 1.02%.