A hybrid switching VSC based converter for reactive power compensation in utility grid

In high power applications such as static synchronous compensator (STATCOM) used for reactive power compensation, it is essential to reduce semiconductor losses and associated cost to a minimum value while maintaining desired key attributes. This paper presents a new hybrid switching STATCOM that addresses the semiconductor device losses while ensuring the usual STATCOM operating criterion. Design and control of the hybrid STATCOM are presented followed by real-time simulation results to validate the proposal. Losses are calculated and the results are compared with a conventional two-level voltage source converter (VSC) based STATCOM to quantify the benefits of the proposed hybrid STATCOM. It is demonstrated that the proposed hybrid STATCOM achieves close to 10% lower semiconductor losses compared with a conventional two-level STATCOM.