In modern induction motor drives an increase of transistors' switching frequency and a decrease of switching times are the sources of some serious problems. The high dv/dt and the common mode voltage generated by the inverter PWM control results in the appearances of bearing currents, shaft voltages, motor terminal overvoltages, the decrease of motor efficiency, and electromagnetic interference. The aspects of common mode (CM) voltage and current in voltage source inverters and ac motors are illustrated in the chapter. The generation of CM voltages is a result of PWM operation of the inverter and is further explained. A CM motor equivalent circuit is analyzed and emphasis is placed on the bearing currents (their types and briefed description are listed). Some aspects of CM current limitation, especially the CM choke, are presented. A simple motor CM model is presented and the method for motor CM parameters determination is included. A significant part of the chapter is dedicated to the active methods for CM currents limitation based on PWM modifications.
Authors
Additional information
- DOI
- Digital Object Identifier link open in new tab 10.1002/9781118755525.ch21
- Category
- Publikacja monograficzna
- Type
- rozdział, artykuł w książce - dziele zbiorowym /podręczniku o zasięgu krajowym
- Language
- angielski
- Publication year
- 2014
