Distributed generation interface using indirect matrix converter in boost mode with controllable grid side reactive power

Abstract

Indirect matrix converter (IMC) using two stages configuration is topologically more flexible than 3×3 direct matrix converter (DMC). For grid integration of ac type distributed generators, the ac/ac converters need voltage boost function, which can't be achieved by traditional IMC due to its limited input-to-output voltage transfer gain 0.866. Alternatively, reverse power flow operation of IMC can be implemented to meet voltage boost requirement for distributed generation interface. Intuitively, only the generator side power needs to be controlled, since the power will be spontaneously transferred to the grid side due to the lack of energy storage in IMC. However, open-loop operation of grid side (current source side) converter will lead to uncontrollable grid side reactive power. This paper proposes control schemes of IMC with controllable grid side reactive power by means of controlling both the generator and grid side currents coordinately with properly designed control loop. Simulation results are provided to validate the effectiveness of the control schemes for the proposed matrix converter.