说明：  三相DC-AC逆变器的谐波注入SPWM调制技术 性能指标：直流输入350~640V，三相交流输出线电压220V AC，输出功率5kVA，功率因数0.8，输出频率50Hz。
(Harmonic Injection SPWM Modulation Technology for Three-phase DC-AC Inverter Performance indicators: DC input 350 ~ 640V, three-phase AC output line voltage 220V AC, output power 5KA, power factor 0.8, output frequency 50Hz.)