Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
153 words
A method of controlling a three phase inverter circuit which provides improved transition from space vector PWM operation to six step operation, said method comprising the steps of: calculating the space vector PWM times t1, t2 and t0 for space vector PWM operation, t1 and t2 corresponding to non-zero space vectors associated with a commanded space vector and t0 corresponding to a zero space vector, the sum of t1, t2 and t0 equaling a total pulse width modulation control period, TPWM; comparing t0 to 0; setting transition space vector PWM times t1', t2' and t0' for calculated t0 values less than 0 to preserve the non-zero space vector which is closer to the commanded space vector, truncate the non-zero space vector which is farther from the commanded space vector and eliminate the zero space vector; and operating the inverter circuit in accordance with the transition space vector PWM times t1', t2' and t0'.
Claim 2
Independent Claim
153 words
A method of controlling a three phase inverter circuit which provides improved transition from space vector PWM operation to six step operation, said method comprising the steps of: calculating the space vector PWM times t1, t2 and t0 for space vector PWM operation, t1 and t2 corresponding to non-zero space vectors associated with a commanded space vector and t0 corresponding to a zero space vector, the sum of t1, t2 and t0 equaling a total pulse width modulation control period, TPWM; comparing t0 to 0; setting transition space vector PWM times t1', t2' and t0' for calculated t0 values less than 0 to preserve the non-zero space vector which is closer to the commanded space vector, truncate the non-zero space vector which is farther from the commanded space vector and eliminate the zero space vector; and operating the inverter circuit in accordance with the transition space vector PWM times t1', t2' and t0'.
Claim 3
Dependent Claim
108 words
A method of controlling a three phase inverter circuit as claimed in claim 1 further comprising the step of comparing the space vector PWM time t1 to the space vector PWM time t2 for calculated t0 values less than 0 and wherein the step of setting transition space vector PWM times t1', t2' and t0' for calculated t0 values less than 0 comprises setting t0' to 0 and the following steps if t2 is less than t1: setting the transition space vector PWM time t1' equal to the smaller of the two times t1 and TPWM; and setting the transition space vector PWM time t2' equal to TPWM-t1'.
Claim 4
Dependent Claim
77 words
A method of controlling a three phase inverter circuit as claimed in claim 2 wherein the step of setting transition space vector PWM times t1', t2' and t0' for calculated t0 values less than 0 further comprises the following steps if t2 is greater than or equal to t1: setting the transition space vector PWM time t2' equal to the smaller of t2 or TPWM; and setting the transition space vector PWM time t1' equal to TPWM-t2'.
Claim 5
Dependent Claim
141 words
A method of controlling a three phase inverter circuit as claimed in claim 1 further comprising the step of comparing the space vector PWM time t1 to the space vector PWM time t2 for calculated t0 values less than 0 and wherein the step of setting transition space vector PWM times t1', t2' and t0' for calculated t0 values less than 0 comprises setting t0' to 0 and the following steps if t2 is less than t1: setting the transition space vector PWM time t2' to the algebraic sum of t2 and t0; comparing t2' to 0; setting the transition space vector PWM time t2' to 0 and the transition space vector t1' to TPWM if t2' is less than 0; and setting the transition space vector PWM time t1' to t1 if t2' is greater than or equal to 0.
Claim 6
Dependent Claim
111 words
A method of controlling a three phase inverter circuit as claimed in claim 4 wherein the step of setting transition space vector PWM times t2' and t0' for calculated to values less than 0 further comprises the following steps if t2 is greater than or equal to t1: setting the transition space vector PWM time t1' to the algebraic sum of t1 and t0; comparing t1' to 0; setting the transition space vector PWM time t1' to 0 and the transition space vector t2' to TPWM if t1' is less than 0; and setting the transition vector PWM time t2' to t2 if t1' is greater than or equal to 0.