A large capacity PCS applied to PMSG (permanent magnet synchronous generator) of wind turbine has been developed. This PCS is characterized by snubber-less circuit, as a result, it is accomplished miniaturize and high reliability. To obtain not only a maintenance-free but also robustness for dc over voltage at the over speed of the wind turbine, the film capacitor which possesses a high energy density is adopted for a dc-circuit. Three kinds of tests were carried out. First, the IGBT shut-off test was examined under the worst condition for this PCS. This test result showed that the IGBT surge voltage was less than an allowable limit. Second, the method of the run-back test was established, as the load which is actually same condition is given for the PCS. The PCS was operated stably during heat run test. Third, the characteristic test for the reactive power was carried out with run back test bench, and this test verified the reactive power of grid was able to control with tracking reference from the system controller. As a result of these tests, the PCS achieved satisfactory performance for the PMSG of the wind turbine.
