Patent ID: 6751105
Filing Date: 2004-06-15
Classification: H02M

Abstract:
A PWM pulse control method of a three-phase two-level inverter, said PWM pulse control method comprising steps of:defining the state of a phase of a load as a first state when an output terminal of said phase is connected to a positive bus that leads from the positive electrode side of a dc power supply; defining the state of said phase as a second state when said output terminal is connected to a negative bus that leads from the negative electrode side of said dc power supply; defining an output voltage vector in which the output states of all phases are said first state as an Op-vector; defining an output voltage vector in which the output states of all phases are said second state as an On-vector; defining an output voltage vector in which the output state of one of the phases is said first state and the output states of the other two phases are said second state as an a-vector;defining an output voltage vector in which the output state of one of the phases is said second state and the output states of the other two phases are said first state as a b-vector; for a first interval in which said Op-vector and said b-vector are successively output within a cycle of a PWM carrier signal, dividing the output time of each vector in said first interval by a first set value, which is a positive integer, to find divided times of each vector;alternately outputting said Op-vector and said b-vector, each time for exactly the time interval of said divided times, each vector being output the number of times that has been established as said first set value; for a second interval in which said On-vector and said a-vector are successively output within said cycle, dividing the output time of each vector in said second interval by a second set value, which is a positive integer, to find divided times of each vector; alternately outputting said On-vector and said a-vector, each time for exactly the time interval of said divided times, each vector being output the number of times that has been established as said second set value; andgenerating PWM pulses based on the divided times of each output vector.