Control apparatus for AC rotary machine and method for measuring electrical constant of AC rotary machine using the control apparatus

1. A control apparatus for an AC rotary machine, wherein the AC rotary machine is driven on a basis of current commands on rotating two-axis coordinates which rotate at an angular frequency of the AC rotary machine, the control apparatus comprising:

current detection means for detecting currents of the AC rotary machine;

coordinate transformation means for transforming current detection values from said current detection means, into current detection values on the rotating two-axis coordinates;

first voltage command calculation means for calculating first voltage commands on the rotating two-axis coordinates, from relational formulas among the current commands on the rotating two-axis coordinates, the angular frequency and a plurality of electrical constants of the AC rotary machine;

second voltage command calculation means for calculating second voltage commands on the rotating two-axis coordinates, on a basis of difference currents between the current commands on the rotating two-axis coordinates and the current detection values on the rotating two-axis coordinates, so that the difference currents may converge into zero;

third voltage command calculation means for calculating third voltage commands on the rotating two-axis coordinates, by adding the first voltage commands on the rotating two-axis coordinates and the second voltage commands on the rotating two-axis coordinates;

voltage application means for applying voltages to the AC rotary machine on a basis of the third voltage commands on the rotating two-axis coordinates,

wherein said first voltage command calculation means sets at least one of the plurality of electrical constants with a constant set value inputted from outside; and

constant measurement means for calculating the constant set value on a basis of the second voltage commands from said second voltage command calculation means.

2. The control apparatus for an AC rotary machine as defined in claim 1 , wherein said constant measurement means calculates the constant set value on the basis of the second voltage commands from said second voltage command calculation means, the current commands and the angular frequency.

3. The control apparatus for an AC rotary machine as defined in claim 1 , wherein

the AC rotary machine is a synchronous machine, and

said constant measurement means calculates an armature resistance set value as the constant set value, on a basis of a component of the second voltage command.

4. The control apparatus for an AC rotary machine as defined in claim 1 , wherein

the AC rotary machine is a synchronous machine, and

said constant measurement means calculates an armature inductance set value as the constant set value, on a basis of a component of the second voltage command.

5. The control apparatus for an AC rotary machine as defined in claim 2 , wherein

the AC rotary machine is a synchronous machine, and

said constant measurement means calculates an armature resistance set value as the constant set value, on a basis of a component of the second voltage command and a component of the current command.

6. The control apparatus for an AC rotary machine as defined in claim 2 , wherein

the AC rotary machine is a synchronous machine, and

said constant measurement means calculates an armature inductance set value as the constant set value, on a basis of a component of the second voltage command, a component of the current command, and the angular frequency.

7. The control apparatus for an AC rotary machine as defined in claim 1 , wherein

the AC rotary machine is a synchronous machine having a saliency, and

said constant measurement means calculates a component set value of an armature inductance as the constant set value, on a basis of a component of the second voltage command.

8. The control apparatus for an AC rotary machine as defined in claim 1 , wherein

said constant measurement means calculates a component set value of an armature inductance as the constant set value, on a basis of a component of the second voltage command.

9. The control apparatus for an AC rotary machine as defined in claim 2 , wherein

the AC rotary machine is a synchronous machine having a saliency, and

said constant measurement means calculates a component set value of an armature inductance as the constant set value, on a basis of a component of the second voltage command, a component of the current command, and the angular frequency.

10. The control apparatus for an AC rotary machine as defined in claim 2 , wherein

said constant measurement means calculates a component set value of an armature inductance as the constant set value, on a basis of a component of the second voltage command, a component of the current command, and the angular frequency.

11. The control apparatus for an AC rotary machine as defined in claim 1 , wherein

the AC rotary machine is a synchronous machine, and

said constant measurement means calculates a phase difference between an axis of the rotating two-axis coordinates and a rotor magnetic flux of the AC rotary machine, on a basis of a component of the second voltage command, and further calculates an angular frequency set value of the AC rotary machine as the constant set value, on a basis of the phase difference and a rotational position detection value of the AC rotary machine.

12. The control apparatus for an AC rotary machine as defined in claim 1 , wherein

the AC rotary machine is a synchronous machine, and

said constant measurement means calculates a magnetic flux amplitude set value of the AC rotary machine as the constant set value, on a basis of a component of the second voltage command.

13. The control apparatus for an AC rotary machine as defined in claim 1 , wherein

the AC rotary machine is an induction machine,

said first voltage command calculation means calculates a slip angular frequency of the AC rotary machine, on a basis of the current commands on the rotating two-axis coordinates and the electrical constant, and the control apparatus further comprises:

an adder which calculates an angular frequency of the AC rotary machine from the slip angular frequency and an angular frequency detection value of the AC rotary machine is disposed.

14. The control apparatus for an AC rotary machine as defined in claim 13 , wherein said constant measurement means calculates any of an armature inductance set value, a rotor inductance set value and a mutual inductance set value as the constant set value, on a basis of a sum between a first axial component and a second axial component of the second voltage commands.

15. The control apparatus for an AC rotary machine as defined in claim 13 , wherein said constant measurement means calculates a rotor resistance set value as the constant set value, on a basis of a difference between a first axial component and a second axial component of the second voltage commands.

16. The control apparatus for an AC rotary machine as defined in claim 13 , wherein said constant measurement means calculates the constant set value on a basis of the second voltage commands from said second voltage command calculation means, the current commands, and the angular frequency.

17. The control apparatus for an AC rotary machine as defined in claim 1 , wherein said constant measurement means calculates the constant set value, only in a case where the angular frequency falls within a range of a predetermined value or more, and the constant measurement means stops the calculation of the constant set value within a range in which the angular frequency is less than the predetermined value.

18. The control apparatus for an AC rotary machine as defined in claim 1 , further comprising:

magnetic flux adjustment means for calculating a first axial component of the current command on a basis of the third voltage commands and the angular frequency so that, letting ω BASE denote a maximum angular frequency at which a voltage saturation does not occur, and V BASE denote a maximum voltage amplitude which said voltage application means can output,

(Angular frequency of the AC rotary machine)/ω BASE =(Amplitude of the third voltage commands)/V BASE is satisfied.

19. A method for measuring an electrical constant of an AC rotary machine executed by a control apparatus for the AC rotary machine, wherein the AC rotary machine is driven on a basis of current commands on rotating two-axis coordinates which rotate at an angular frequency of the AC rotary machine, said method comprising:

detecting, at the control apparatus, currents of the AC rotary machine;

transforming, at the control apparatus, the currents of the AC rotary machine into current detection values on the rotating two-axis coordinates;

calculating, at the control apparatus, first voltage commands on the rotating two-axis coordinates, from relational formulas among the current commands on the rotating two-axis coordinates, the angular frequency and a plurality of electrical constants of the AC rotary machine;

calculating, at the control apparatus, the second voltage commands on the rotating two-axis coordinates, on a basis of difference currents between the current commands on the rotating two-axis coordinates and the current detection values on the rotating two-axis coordinates, so that the difference currents converges into zero;

calculating, at the control apparatus, third voltage commands on the rotating two-axis coordinates, by adding the first voltage commands on the rotating two-axis coordinates and the second voltage commands on the rotating two-axis coordinates;

applying, at the control apparatus, voltages to the AC rotary machine on a basis of the third voltage commands on the rotating two-axis coordinates;

setting, at the control apparatus, at least one of the plurality of electrical constants with a constant set value inputted from outside; and

calculating, at the control apparatus, the constant set value on a basis of the second voltage commands.

20. A control apparatus for an AC rotary machine, wherein the AC rotary machine is driven on a basis of current commands on rotating two-axis coordinates which rotate at an angular frequency of the AC rotary machine, the control apparatus comprising:

a current detection unit that detects currents of the AC rotary machine;

a coordinate transformation unit that transforms current detection values from said current detection unit, into current detection values on the rotating two-axis coordinates;

a first voltage command calculation unit that calculates first voltage commands on the rotating two-axis coordinates, from relational formulas among the current commands on the rotating two-axis coordinates, the angular frequency and a plurality of electrical constants of the AC rotary machine;

a second voltage command calculation unit that calculates second voltage commands on the rotating two-axis coordinates, on a basis of difference currents between the current commands on the rotating two-axis coordinates and the current detection values on the rotating two-axis coordinates, so that the difference currents may converge into zero;

a third voltage command calculation unit that calculates third voltage commands on the rotating two-axis coordinates, by adding the first voltage commands on the rotating two-axis coordinates and the second voltage commands on the rotating two-axis coordinates;

a voltage application unit that applies voltages to the AC rotary machine on a basis of the third voltage commands on the rotating two-axis coordinates,

wherein said first voltage command calculation unit sets at least one of the plurality of electrical constants with a constant set value inputted from outside; and

a constant measurement unit that calculates the constant set value on a basis of the second voltage commands from said second voltage command calculation unit.