Abstract：Under the power grid dispatch mode of "source follows load"，different AC power supply modes are

required in the market. To meet market demand，an uninterruptible power supply（UPS）system compatible with

various AC power supply modes was designed. The modes of the system were selected by switching devices.

According to the selected mode，different methods of driving control were carried out，and thus the compatibility of various AC power supply modes was realized. To improve the reliability of uninterruptible power supply，a faulttolerant mechanism with compatible modes was also proposed. Finally，an experiment was conducted on a 40 kV·A/36 kW prototype. Experimental results demonstrate that the system can be compatible with various AC power

supply modes，by which the correctness of the design was verified.

      Key words：AC mode compatibility；standard detection；uninterrupted power supply（UPS）