设计一个AC/DC/AC变频器设计，具体参数如下：三相交流输入380V/50Hz，三相输出交流电压500V/400Hz,THD<5 ,负载为一般的阻感负载，功率5000W。-Design of a AC/DC/AC converter design, the specific parameters are as follows: Three-phase AC input 380V/50Hz, three-phase output AC voltage 500V/400Hz, THD < 5 , as a general resistive load inductive load, power 5000W.