METHODS AND APPARATUSES FOR CONTROLLING OUTPUT VOLTAGES OF INVERTERS DRIVING OF ELECTRIC MOTORS

摘要

A method of controlling an output voltage of an inverter driving an electric motor may include removing harmonic components of an output current, which is output to the electric motor, by using a low pass filter and obtaining a fundamental component of the output current; calculating a current total harmonic distortion by using the fundamental component of the output current; comparing the current THD with a reference current THD; determining a pulse width modulation method to be changed from a first modulation method for reducing the harmonic components of the output current to a second modulation method for reducing a switching frequency of the inverter if the current THD is less than the reference current THD, the PWM method modulating a pulse width of a control pulse signal for controlling the output voltage of the inverter; and/or generating the control pulse signal based on the determined PWM method.

主权项

1. A method of controlling an output voltage of an inverter driving an electric motor, the method comprising:
removing harmonic components of an output current, which is output to the electric motor, by using a low pass filter (LPF) and obtaining a fundamental component of the output current; calculating a current total harmonic distortion (THD) by using the fundamental component of the output current; comparing the current THD with a reference current THD; determining a pulse width modulation (PWM) method to be changed from a first modulation method for reducing the harmonic components of the output current to a second modulation method for reducing a switching frequency of the inverter if the current THD is less than the reference current THD, the PWM method modulating a pulse width of a control pulse signal for controlling the output voltage of the inverter; and generating the control pulse signal based on the determined PWM method.