Design of sampling signal conditioning circuits for DSP-controlled grid-connecting photovoltaic inverter

This paper discusses several sampling signal conditioning circuits for grid-connecting photovoltaic inverter. In this inverter design, the main circuit is isolated with the control parts for safety and anti-interference, therefore all the voltages and currents are sampled by relative sensors. In consideration of the process speed of DSP and the switching period of the inverter, almost all the signal pre-conditionings are handled by the hardware before they are into the DSP. The operation amplifiers and comparators implement all sampling signal conditionings. The test results verify these conditioning methods of the sampling signals are valid and satisfy the DSP control requirements.