Title :
Over-voltages computation algorithm for motors fed from long cable PWM drives
Author :
Amarir, Saïd ; Al-Haddad, Kamal
Author_Institution :
Canada Res. chair in Electr. Energy conversion & power Electron., Ecole de Technol. Super., Montreal, QC
Abstract :
This work presents a computation technique to analyze the high frequency over-voltage problem in long cable PWM drives. Differential mode (DM) analysis for voltage and its resulting current along the cable is first developed in the frequency domain. The cable length, its electrical characteristics (R,L,G,C), the motor impedance, the inverter impedance as well as voltage rise and fall times are all considered. Then, by applying the boundary conditions at the cable ends and assuming the cable without losses, delay equations, describing the voltage at the inverter side as well as the voltage at the motor side, are developed in time domain. From these equations, an appropriate algorithm has been deduced to model the voltage at the motor terminals. This paper includes computation results, carried out using Matlab software, and important experimental outcomes on an industrial 5 kVA ASD prototype.
Keywords :
PWM invertors; cables (electric); electric motors; overvoltage; differential mode analysis; electrical characteristics; inverter impedance; long cable PWM drives; motor impedance; over-voltages computation algorithm; pulse width modulation; Boundary conditions; Delay effects; Delta modulation; Electric variables; Equations; Frequency domain analysis; Impedance; Pulse width modulation; Pulse width modulation inverters; Voltage; Cables; electromagnetic interference (EMI); electromagnetic transient propagation; insulated gate bipolar transistors; over-voltage; pulse width modulation; variable speed drives;
Conference_Titel :
Electrotechnical Conference, 2008. MELECON 2008. The 14th IEEE Mediterranean
Conference_Location :
Ajaccio
Print_ISBN :
978-1-4244-1632-5
Electronic_ISBN :
978-1-4244-1633-2
DOI :
10.1109/MELCON.2008.4618493