System and method for testing temperature rise and efficiency under rated power of high-power photovoltaic inverter

The invention relates to a system and a method for testing temperature rise and efficiency under the rated power of a high-power photovoltaic inverter. The system comprises the high-power photovoltaic inverter, an external test circuit and a control host, wherein the test circuit is connected between a power grid and the inverter; and the control host is respectively connected with a common direct current (DC) bus, current sensors, temperature sensors and output ends of the inverter and acquires and calculates corresponding data. The test method comprises the following steps that: a signal acquisition module, an arithmetical operation module, a drive output module and a man-machine interface module are arranged in the control host, the arithmetical operation module operates the acquired information to generate six paths of pulse signals, power units of the inverter are controlled by the drive output module, and a calculation result is obtained. The system is simple in circuit, the method is stable, and test energy consumption is low.