Abstract:

For the low-voltage,high-current DC power supply aging test requiring discharge load,a feed-type DC electronic load is developed.The pre-stage DC-DC converter uses the H-bridge Boost circuit as the main circuit topology to implement discharge load characteristics and achieve boost and maintain the stability of output terminal voltage.The post-stage DC-AC converter adopts TMS320F2812 as the main control chip and current-loop as control strategy and applies grid voltage feed-forward control,so that this system can approach unity power factor to feed energy back to the grid under a set power,and the total harmonic distortion of the grid-connected current does not exceed 5%,which meets the requirements for grid-connection.

Key words: electronic load, H-bridge Boost circuit, current loop control, voltage feed-forward control, unit power factor