Hysteresis Current Regulator Research Articles

Generator Operation of Switched Reluctance Machine Drives for Electric Vehicles

This contribution deals with the stringent control requirements of switched reluctance generators for electric vehicle (EV) applications. In EV applications, switched reluctance machines have to operate in generating mode over a wide torque-speed range, i.e. in the current controlled chopping mode at low speed as well as in the voltage controlled single-pulse operation at high speed. In addition, the d.c.-bus voltage varies with the load as a function of the energy source. This voltage variation requires continuous variable adaptation when a wide speed range is required. Furthermore, a novel control strategy to implement a three-level hysteresis current regulator for generating mode is presented. This technique improves drive efficiency up to 8% over a wide operating area. In addition, the problem of uncontrollable overcurrents due to excessive back-EMF voltage during generating mode is discussed. Therefore, the variables, which are necessary to control the switched reluctance drive, and the resulting efficiency characteristics are presented.

Integrated active rectifier and power quality compensator with reduced current measurement

This paper describes a three-phase integrated active rectifier and shunt power quality compensator (IPQC). The measurement of only three currents is required, and the control algorithm can be implemented using a low-cost controller. The IPQC improves the harmonic content of the supply current, displacement power factor, supply current balance, and can serve as a four-quadrant active rectifier for motor drives and other DC-link loads. The operation of the IPQC is experimentally verified using a conventional three-phase insulated gate bipolar transistor voltage-source inverter. A low-cost fixed-point DSP-based controller with fixed-band hysteresis current regulation is used for the implementation of the control algorithms.