| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a PWM control voltage type inverter which operates with high efficiency and expands an operating range. <P>SOLUTION: A PWM control portion 2 proceeds to a step S3 when the sum of τa, τb and τc calculated by a pulse width operation part 2a is discriminated to exceed a carrier period T at a step S2. Then, the control portion proceeds to a step S4 when the sum of τa and τb is discriminated to exceed the carrier period T at the step S3, when the sum of τa and τb is discriminated not to exceed the carrier period T, the control portion proceeds to a step S5, and τc=T-τa-τb is set. When τb is discriminated to exceed τa at the step S4, τa=T-τb, τc=0 are set at a step S6. On the other hand, if τb is discriminated not to exceed τa at the step S4, τb=T-τa, τc=0 are set at a step S7. A PWM portion outputs a control signal to an inverter so that the inverter outputs a voltage pattern in which a pulse width is expressed as three voltage vectors of τa, tb and τc, respectively. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
