The topology of single-stage DC-AC power frequency transformer is used in this system, the main circuit is half-bridge inverter circuit driven by integrated circuit IR 2110. ARM core microcontroller LPC2148 is the core of the control circuit, and the DC-AC inverter is controlled by the SPWM wave which is generated by software. Through the frequency and phase being monitored by the feedback signal, and A/D sampling being employed by the under-voltage and over-current signal, frequency and phase tracking and under-voltage and over-current protection are controlled by the system, and a novel measurement of frequency and phase was presented. By testing, the conversion efficiency of this system is high and the distortion of output sine-wave is small, the same frequency and phase control can be achieved, as well as the function of under-voltage and over-current protection.