Implementation of programmed modulated carrier HCC based on analytical solution for uniform switching of voltage source inverters

An analytical basis is established in this paper for a programmed function of known amplitude to be added to the feedback path of a hysteresis current controller (HCC) in a static power inverter. Improper amplitude and slope of the carrier waveform in a modulated carrier HCC frequently encounter the problem of sudden high frequency switching. Though intuitive approaches exists to tackle the problem practically, proper analytical basis has not been established so far. This paper deals with solving the problem analytically, so that implementation of such scheme for an inverter operation can be done systematically and accurately. A theoretical model of programmed ramp comparison HCC (PRCHCC) is developed in this paper that defines a carrier waveform based on inverter supply voltage, load parameters and reference current waveform. The parameters of the carrier waveform of PRCHCC can be deterministically predicted for uniform switching frequency operation. Simulation and experimental results highlights the potential of the proposed model for uniform switching at all operating conditions.