An indirect matrix converter for CCHP microturbines in data center power systems

Data centers (DCs) are considered critical loads that require premium power from utilities to ensure reliability at all times. Microturbine (MT) generation systems are becoming important in DCs, not only as distributed generation (DG) for supplying electricity, but also for providing cooling and heating functions, which is known as combined cooling, heat and power (CCHP) or tri-generation. This paper considers the use of an indirect matrix converter (IMC) as the power electronic interface (PEI) to connect a permanent magnet synchronous generator (PMSG) with the power grid in a DC. First, the paper analyzes the semiconductor losses for the IMC and the conventional back-to-back converter (BBC) as a function of the switching frequency in order to determine the favorable operating conditions for the IMC. It then presents a new control strategy that does not require measuring the grid voltages to inject the commanded power into the grid at unity power factor. Simulation results of a 15-kVA, 480-Vrms IMC-based MT generation system show the effectiveness of the proposed control technique for this particular application.