Software-controlled electronic circuit for switching power to a three-phase motor

摘要

The method of controlling a rotating three-phase motor involves generating in synchronism with the rotation of the motor a variable duty cycle pulse-width modulated signal for each of the switching circuit components used to supply current to the motor coils. The generated variable duty cycle pulse-width modulated signals control the switching circuit components to selectively place pairs of motor coils in current conducting states and to develop an associated varying voltage for each of the phases. This varying voltage is monitored to identify the one phase that is at a voltage in between the voltages of the other two phases. Then for the identified one phase, the variable duty cycle pulse-width modulated signal is specially generated so that when the switching circuit components of the other two phases are concurrently switched on, the switching circuit component of the identified one phase is not switched on.

主权项

1. A method of controlling a rotating three-phase motor of the type having three interconnected motor coils, each corresponding to one of three phases and each supplied with current through at least one of a plurality of switching circuit components, comprising:
generating in synchronism with the rotation of the motor a variable duty cycle pulse-width modulated signal for each of the switching circuit components; using the generated variable duty cycle pulse-width modulated signals to control switching circuit components to selectively place pairs of motor coils in current conducting states and to develop an associated varying voltage for each of the phases; monitoring duty cycle of each of the three phases to identify one phase that is at a voltage in between the voltages of the other two phases; and for the identified one phase, generating said variable duty cycle pulse-width modulated signal so that when the switching circuit components of the other two phases are concurrently switched on, the switching circuit component of the identified one phase is not switched on.