Optimisation of switching losses and harmonic performance using Model Predictive Control of a Cascaded H-bridge multi-level StatCom

This paper further develops a Model Predictive Control (MPC) scheme which is able to exploit the large number of redundant switching states available in a multi-level H-bridge StatCom (H-StatCom). The new sections of the scheme provide optimised methods to trade off the harmonic performance with converter switching losses and capacitor voltage ripple. Varying the pulse placement within the modulation scheme and modifying the heuristic model of the voltage balancing characteristics allows the MPC scheme to achieve superior performance to that of the industry standard phase shifted modulation technique. Simulation and experimental results are presented that confirm the correct operation of the control and modulation strategies.