Grid Emulator-based Testing of Power Factor Correction Circuit

Power factor correction (PFC) circuits are employed as the front-end converters that convert AC power to DC power. These PFC circuits are connected to the ac grid that is prone to voltage sag, swell and distorted voltages. The PFC circuit behavior under these conditions has to be studied before connecting it to the actual ac grid. To emulate these conditions, power electronic converters based grid emulators are becoming popular because of their advantages in the testing and validation stage of hardware. Conventionally, grid emulators are realized with a back-to-back connected converter with a common dc-link, The output voltage of the DC-AC converter is controlled using closed-loop control to track the required output voltage reference. However, literature presents solutions for emulating grid using open-loop operation without an output LC filter for a three-phase grid-connected AC-DC converter. This idea of emulating grid voltage is extended to test a single-phase totem-pole power factor correction (TPPFC) circuit in this paper. The grid emulator hardware is tested with the TPPFC circuit as the converter under test, and performance of TPPFC is evaluated under conditions such as voltage sag, swell and distorted grid voltages.