Multiple-loop Control Technology of Inverters

In order to enhance the steady state precision and dynamic responsibility of the inverter, this paper pre-sents a multiple-loop control technology of inverters. The scheme incorporates a current loop with an instantaneous voltage loop. Besides, a repetitive control outer loop is added. Since both output voltage decoupling mechanism and load distur-bance compensation have been used, the current loop and instantaneous voltage loop controller is designed through dead-beat theory, so that the inverter can achieve very fast dynamic response. Simultaneously, the repetitive control outer loop improved the steady state performance. Experimental results show the output THD (total harmonic distortion) of inverter with multi-loop control is only 1.54%, whereas it is 4.84% without multi-loop control. The scheme is proved on a PWM inverter whose control system is based on DSP TMS320F240.