Patent ID: 9013137
Filing Date: 2015-04-21
Classification: B60L,H02P,Y02T

Abstract:
1. A system for a salient-pole multi-phase rotary machine, the system driving, based on a PWM signal for each phase of the salient-pole multi-phase rotary machine, an inverter equipped with a first switching element, a first diode connected in antiparallel to the first switching element, a second switching element, and a second diode connected in antiparallel to the second switching element, so that the inverter connects a terminal of the salient-pole multi-phase rotary machine selectively to one of a positive terminal and a negative terminal of a direct voltage power supply via the respective first and second switching elements to thereby control a controlled variable of the rotary machine, the first and second switching elements being turned on or off with a dead time during which both the first and second switching elements are off, the system comprising: a superimposing element configured to superimpose a high-frequency voltage signal on an output voltage of the inverter, the high-frequency voltage signal having a frequency higher than an electrical angular frequency of the rotary machine, the high-frequency voltage signal being correlated with a measured value of a high-frequency current signal flowing in the rotary machine; a calculating element configured to calculate a rotational angle of the rotary machine based on the measured high-frequency the current signal flowing in the rotary machine; a dead-time compensating element configured to perform a compensation task that shifts a start edge and an end edge of an on-command duration of the PWM signal for each of the first and second switching elements by a preset same time to compensate for a first error; the first error being generated between the high-frequency voltage signal actually superimposed on the output voltage of the inverter and the command value for the high-frequency voltage signal due to change of the PWM signal by the dead time; and a current manipulating element configured to manipulate a command current for controlling the controlled variable of the rotary machine to prevent the calculating element from calculating the rotational angle of the rotary machine based on the measured high-frequency current signal flowing in the rotary machine, the measured high-frequency current signal including a second error, the second error being generated based on difference in lyase between the PWM signal for one phase current that crosses through zero level and the PWM signal for another phase current, the second error being generated between the high-frequency voltage signal actually superimposed on the output voltage of the inverter and the command value for the high-frequency voltage signal even after the compensation task is performed by the dead-time compensating element.