Effects of using DC-side average current-mode control on a three-phase converter with an input filter and distorted supply

The use of DC-side current sensing and proportional plus integral average current-mode control is aiialysed and shown to have several bencficial effects when applied to a three-phase, stepdown, AC-DC, unity-power-factor converter. Conventionally, a large DC-side inductor was uscd with the considered converter, in order to reduce the propagation of harmonic currcnts due to nonsinusoidal supply voltages that result in the input currents being non-sinusoidal. A single DC-sidc currcnt sensor, when used with an EPROM sinusoidal look-up tablc PWM modulation method, is shown to have a number of benefits including; reduction or thc harmonic currents when a finite-value DC-side inductor is used, hence giving near-sinusoidal input currcnts and damping of tlie DC-side LC filler. Two other benefits arc mentioned. The current-control loop is dcsigncd and the often ignored effect of the input filter on system stability is discussed. Two SIMULIN Kʹ" simulation models arc developed and compared with each other.