Abstract: Abstract:In order to test low voltage ridethrough(LVRT) function of high power photovoltaic converter, designing work of high power grid simulator is in need. Based on TI Company′s floatingpoint DSC processor—TMS320F28335, researchers structured a dual threephase bridge inverter system, i.e. integrating controllable rectifier and converter system into of dual threephase bridge system, for the purpose of creating grid simulator. Sampling voltage and set voltage were performed on double dq decomposition, thus segregating positive and negative sequence voltage, to realize asymmetric voltage drop. Meanwhile, a 100Hz notch filter was adopted in the decomposition process.Connected with photovoltaic converter, a power loop was formed; the system completed LVRT performance test successfully with only a little power consumption.

Key words: Keywords:dq transform, low voltage ridethrough(LVRT), gird simulator, photovoltaic inverter