A Novel Control DC-DC-AC Buck Converter for Single Phase Capacitor-Start-Run Induction Motor Drives

A novel control DC-DC-AC buck converter for single phase capacitor-start-run induction motor drives is presented in this paper. The objective is to minimize harmonic distortion in inverter output voltage supply to a Single Phase Induction Motor (SPIM). Here, the output of a variable duty cycle buck DCDC converter is fed to an H-bridge inverter to generate a very close sinusoidal output voltage. Few power semiconductor switches are utilized to produce inverter output voltage with reduced harmonic distortion comparable with results achieved in multilevel inverters. The SPIM was analysed in the stationary d-q reference frame while the buck converter was operated in the Continuous Conduction Mode (CCM) to ensure that the output voltage vary exactly as the duty cycle. The simulation results show good starting transient characteristics for the SPIM and also stable operation under intermittent loading of 4 N-m. The average inverter output voltage of 157.4 V was achieved with Total Harmonic Distortion (THD) as low as 6.32 %. This configuration is simple, cheap, and has reduced control complexity

A new four quadrant field orientation-controlled three-phase induction motor drive based on hysteresis current comparison

A new four quadrant Field Orientation-Controlled (FOC) three-phase induction motor drive based on Hysteresis Current Comparison (HCC) has been developed. The direct relationship between current and torque in the Direct-Quadrature ($dq$) reference frames has been exploited to develop an HCC scheme that offers accurate tracking of current and torque based on the pulse width modulation technique. The parameters of the inner HCC and the outer Proportional-Integral (PI) speed controllers have been optimised to obtain effective current and torque tracking. The complete closed loop system being speed-controlled, four quadrant operation has been obtained using step speed input while the suitability of the developed model has been tested under full load stress during steady state. The results obtained satisfy the four quadrant operation requirements of advanced drives where controlled starts and stops are essential in both forward and reverse directions. This is evident in the effectiveness of current and torque tracking and ease of speed transition from motoring to regeneration and vice versa. The developed model finds applications in advanced industrial drives as an energy-efficient and cost-effective alternative to eliminate the effects of supply voltage drops and mechanical load variations