Control system for a rotary machine

摘要

An estimation section calculates estimated currents corresponding to switching modes, which are provisionally set by a mode setting section. A mode determination section determines one of modes, which has a smallest difference between the estimated currents and command currents, to be a final switching mode. A drive section drives an inverter in the switching mode determined by the determination section. The estimation section uses transient-state inductances as coefficients of time differentiation of currents in voltage equations used for estimation of the estimated currents. These are different from steady-state inductances, which are coefficients of multiplication of currents and electric angular velocity.

主权项

1. A control system for a rotary machine comprising:
a power conversion circuit, which includes switching devices and controls a control amount including at least one of current, torque and flux linkage of the rotary machine by turning on and off the switching devices, the switching devices turning on and off connection of voltage supply sections, which supply respective voltages different one another, and terminals of the rotary machine; an estimation section, which sets provisionally switching modes indicating an on/off condition of each of the switching devices and estimates the control amount with respect to each of the switching modes; a determination section, which determines a switching mode based on an estimation result of the estimation section, the determined switching mode being used to actually drive the power conversion circuit; and a drive section for driving the power conversion circuit in correspondence to the determined switching mode, wherein the estimation section estimates the control amount or a change amount based on inductance information of the rotary machine, the change amount corresponding to the switching mode provisionally set for a parameter for calculating the control amount, and wherein the inductance indicated by the inductance information has a value, which is different from a ratio between the current flowing in the rotary machine and the flux linkage; wherein the estimation section includes:
an average voltage calculation section for calculating an average value of an output voltage of the power conversion circuit;an instantaneous voltage calculation section for calculating an instantaneous voltage as a difference of the output voltage of the power conversion circuit corresponding to the provisionally set switching mode relative to the average value calculated by the average voltage calculation section: anda change amount estimation section for estimating the change amount based on the instantaneous voltage and the inductance in formation.