Space vector-based current controlled pwm inverter for motor drives

A controller for commanding a plurality of output circuits each having an upper side switch and a lower side switch connected in series for supplying a current to a motor from a connection point between said upper side switch and said lower side switch of each output circuit, comprising:

• a current detection resistor connected in series with said plurality of output circuits in common for detecting a current supplied to said plurality of output circuits;
• a position detection circuit for outputting position signals corresponding to a position of a rotor of said motor;
• a current command generation circuit for generating target current command signals based on said position signals and a predetermined phase angle in which a phase angle of said target current command signal is determined by said predetermined phase angle;
• and
• a space vector modulation based logic control circuit for commanding a plurality of output circuits that are set in a plurality of switches states for control of said motor, wherein said space vector modulation based logic control circuit commands said switches to generate patterns of said switch states according to said target current command signal, said position signals, and a feedback current signal generated at said current detection resistor so that each of a plurality of periods obtained by dividing a time period corresponding to said patterns of said switch states includes a first period in which a voltage vector as a function of said target current command signal, said position signals, and said feedback current signal is to determine said switch states of said plurality of output circuits and a second period in which said voltage vector as a function of said target current command signal, and said feedback current signal is to determine said switch states of said plurality of output circuits.

A method for controlling an electric motor with an inverter that has a plurality of switches which can be commanded to a plurality of switch states, and a current detection resistor connected in series with said inverter, comprising the steps of:

• detecting a current supplied to said plurality of switches;
• outputting position signals corresponding to a position of a rotor of said motor;
• generating target current command signals based on said position signals and a predetermined phase angle in which a phase angle of said target current command signal is determined by said predetermined phase angle;
• and
• commanding a plurality of switches that are set in a plurality of switches states for control of said electric motor, wherein said space vector modulation based logic control circuit commands said switches to generate patterns of said switch states according to said target current command signal, said position signals, and a feedback current signal generated at said current detection resistor so that each of a plurality of periods obtained by dividing a time period corresponding to said patterns of said switch states includes a first period in which a voltage vector as a function of said target current command signal, said position signals, and said feedback current signal is to determine said switch states of said plurality of output circuits and a second period in which said voltage vector as a function of said target current command signal, and said feedback current signal is to determine said switch states of said plurality of output circuits.