JP2007306756A - Controller for wound field synchronous machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller of a wound field synchronous machine, capable of keeping the current control response of windings uniform, corresponding to changes in the operating state. <P>SOLUTION: A parameter setter stores the reference control parameters of a stator and a field current control system that assumes operating state of the synchronous machine; inputs and calculates current command values to the stator and field winding from an external control system; and then multiplies the result with a reference parameter for outputting it to a stator winding current and the field current control system. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device for a winding field synchronous machine that generates a field magnetic field by a field winding of a rotor, and particularly enables stable current control in response to changes in operating conditions. This relates to the control device.

  In the control of a rotating machine such as a winding field type synchronous machine, so-called current feedback control is performed in which the current flowing through each winding is controlled to a desired value, and the voltage applied to the winding is detected and applied. Done. For this control, a PI controller that performs proportional-integral control of the current control system is generally used. The control parameter to be set in this controller is a physical characteristic value (resistance, inductance) of the winding to be controlled. And the required control responsiveness. However, in an actual rotating machine, these physical characteristic values vary depending on operating conditions, and therefore the same control response cannot be maintained with the control parameters of the controller kept constant. On the other hand, for a permanent magnet motor, for example, a method has been proposed in which the control parameters of the current control device are made variable according to operating conditions (output voltage, output frequency, motor temperature, etc.) (for example, Patent Document 1).

JP 2001-275382 A (13th to 16th paragraphs, FIG. 1)

However, since the control device disclosed in Patent Document 1 is intended for a permanent magnet motor having a winding only on the stator, it has a field winding on the rotor side, and the stator current and the field current. However, there is a problem that the same method cannot be applied to the wound field type synchronous machine whose operating state changes due to the interaction of.
The present invention has been made to solve the above-described problems, and in a winding field synchronous machine, the current control responsiveness of each winding can be kept the same even if the operating state changes. An object of the present invention is to realize a control device for a winding field type synchronous machine.

A control device for a winding field type synchronous machine according to the present invention comprises a multiphase inverter connected to a stator winding, and a single-phase amplifier connected to a field winding, d-axis current of the stator winding, q-axis Stator current control system that drives the multi-phase inverter by controlling the current, field current control system that drives the single-phase amplifier by controlling the current of the field winding, and stator and field current control system The parameter setting unit is used to set the control parameters of the synchronous machine. The parameter setting unit stores the reference control parameters of the stator and field current control system assuming the operating state of the synchronous machine, and is fixed from the host control system. Calculation is performed by inputting current command values to the d-axis, q-axis, and field winding of the child winding, and each of the reference control parameters for storing the calculation results is multiplied to obtain a stator current control system and a field winding. Output to the magnetic current control system It is.

  The winding field synchronous machine control device according to the present invention is provided with a stator and a parameter setting unit for setting control parameters of the field current control system, and the parameter setting unit assumes an operating state of the synchronous machine. The reference control parameters of the stator and the field current control system are stored, and the current command values to the d-axis, q-axis and field winding of the stator winding from the upper control system are input to the calculation, Each reference control parameter that stores the calculation result is multiplied and output to the stator current control system and the field current control system, respectively. Therefore, even if the operating state of the synchronous machine changes, the current control response of each winding Therefore, there is an effect that the control can be kept the same and stable control becomes possible.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 shows a control apparatus 100 for a winding field type synchronous machine according to the first embodiment.
A three-phase inverter 2 is connected to the stator winding of the synchronous machine 1, and a single-phase amplifier 3 is connected to the field winding. The current of each winding is a stator current sensor 4 (three phases are shown together) and It is detected by the field current sensor 5. A stator current command and a field current command necessary for causing the synchronous machine 1 to perform a desired operation are supplied from a host control system (not shown). The stator current command is a rotor d-axis, that is, a field magnet. It is divided into a d-axis current component in the same direction as the magnetic flux generated by the winding and a q-axis current component orthogonal to the d-axis, which are given as a d-axis current command and a q-axis current command, respectively. The rotor phase (rotor d-axis phase) is detected by a rotor angle sensor 6. The stator current detected by the stator current sensor 4 is converted into a d-axis current and a q-axis current by the first coordinate converter 7. The first adder 8 subtracts the d-axis current detected and converted by the stator current sensor 4 from the d-axis current command, and the obtained error is input to the d-axis current controller 9 for control calculation. Is called. Similarly, the second adder 10 subtracts the q-axis current similarly converted from the q-axis current command, and the obtained error is input to the q-axis current controller 11 to perform control calculation. The d-axis voltage command output from the d-axis current controller 9 and the q-axis voltage command output from the q-axis current controller 11 are input to the coordinate converter 12 and converted into a three-phase voltage command. The three-phase inverter 2 is driven and a desired voltage is applied to the stator winding of the synchronous machine 1. Here, the three-phase inverter 2, the stator current sensor 4, the first coordinate converter 7, the d-axis current controller 9, the q-axis current controller 11, and the first and second adders 8 and 10 are fixed. A child current control system is configured.

  On the other hand, the third adder 13 subtracts the field current detected by the field current sensor 5 from the field current command, and the obtained error is input to the field current controller 14 for control calculation. The obtained field voltage command is input to the single-phase amplifier 3, and a desired voltage is applied to the field winding of the synchronous machine 1. Here, the single-phase amplifier 3, the field current sensor 5, the third adder 13, and the field current controller 14 constitute a field current control system.

  At this time, in the d-axis current controller 9, the d-axis voltage command Vdref is obtained by the following equation (1) from the d-axis current error Δid. Here, s is a Laplace operator.

  Similarly, in the q-axis current controller 11, the q-axis voltage command Vqref is obtained by the following equation (2) from the q-axis current error Δiq.

  In the field current controller 14, the field voltage command Vfref is obtained by the following equation (3) from the field current error Δif.

  The d-axis proportional gain Kpd, the d-axis integral time constant Tid, the q-axis proportional gain Kpq, the q-axis integral time constant Tiq, the field proportional gain Kpf, and the field integral time, which are control parameters used for the above control calculation. The constant Tif is given by the parameter setting unit 15. The parameter setter 15 stores combinations of control parameters that can obtain desired current control responses in a state of operation with a combination of a d-axis current command, a q-axis current command, and a field current command. Appropriate control parameters can be output by inputting commands.

Next, details of the operation of the parameter setting unit 15 will be described.
If the windings driven by the stator current control system and the field current control system are represented by an equivalent circuit in which a resistor R and an inductance L are connected in series, the transfer function Gco when the voltage is input and the current is output is It is represented by the following formula (4).

  The open loop transfer function Gcc of the current control system when each controller is connected in series as shown in FIG. 1 to the controlled object represented by Expression (4) is represented by the following Expression (5). . At this time, Kp is a proportional gain, and Ti is an integration time constant.

From equation (5), Ti = L / R may be used in order to make the characteristic a simple integral characteristic. Further, since the tolerance frequency ωcc at that time is a value in which the right side becomes 1 when S = ωcc in equation (5), it can be seen that Kp = ωcc · L.
As shown above, the proportional gain of the stator and field current control system can be calculated from the desired current control response ≒ tolerance frequency and inductance, and the integral time constant is divided into the winding resistance and inductance. Can be calculated.
However, in an actual motor, the inductance and resistance of each winding change depending on the operating state, and particularly in a winding field type synchronous machine, the inductance change due to magnetic saturation is large. It is known that the inductance of each winding changes in accordance with the current value of each winding, and there is an interference in inductance change between the d-axis, q-axis, and field windings.
As can be seen from the above description, when the proportional gain of the current control system is constant, the current control response changes when the inductance changes. In order to eliminate this, an inductance change is estimated from each winding current, and the proportional gain of the current control is changed in proportion to the inductance change.

  In order to estimate the inductance from each winding current, it is conceivable to measure the inductance for a combination of several winding currents in advance and formulate this. Specifically, the inductance L is considered as the following equation (6) as a function of the d-axis current id, the q-axis current iq, and the field current if. In the equation (6), the inductance is expressed by a quadratic linear combination of each current, and kd1, kd2, kq1, kq2, kf1, and kf2 are coefficients of each term. L0 corresponds to the inductance when each current is 0, and this value is hereinafter referred to as a reference inductance.

By applying the relationship between each current and inductance measured in advance to Equation (6) and determining each coefficient so that the error is minimized by the least square method or the like, Equation (6) can be obtained for an actual synchronous machine. I can do it. In the above description, a quadratic linear combination is used in the equation, but other equations may be used depending on the characteristics of the inductance change.
For convenience of explanation, the value both sides divided by the reference inductance L0 was of the formula (6) and the inductance coefficient k _L, to be expressed by the following equation (7).

  FIG. 2 shows the detailed processing contents of the parameter setting unit 15. The d-axis, q-axis, and field current commands are input to the d-axis inductance coefficient generator 16, the q-axis inductance coefficient generator 17, and the field inductance coefficient generator 18. Each of the inductance coefficient generators 16, 17, 18 performs calculation corresponding to the equation (7) for each of the d-axis, q-axis, and field inductances, and outputs the inductance coefficient in the current operating state of the synchronous machine 1. . Multipliers 19, 21, and 23 multiply the d-axis, q-axis, and field reference gains by the inductance coefficient, respectively, and calculate d-axis, q-axis, and field current proportional gains. Here, the reference gain is obtained by the following equation (8) using the reference inductance L0. ωcc is the desired current control response.

  The multipliers 20, 22, and 24 multiply the d-axis, q-axis, and field reference time constants by the inductance coefficient, respectively, and calculate the d-axis, q-axis, and field current integration time constants. Here, the reference time constant is obtained by Expression (9) using the reference inductance L0 and the resistance R.

The current control proportional gain and the current control integral time constant obtained for each of the d-axis, q-axis, and field are obtained from the parameter setter 15 as control parameters for the d-axis, q-axis, and field, respectively. Output to the field current control system.
In the above description, the inductance coefficient generators 16, 17, 18 have been described by modeling the inductance characteristics using mathematical formulas. However, as a method for storing and calculating the inductance characteristics in the form of data such as a table regardless of the mathematical formulas. It goes without saying that it is also good. Even in the case of mathematical formulas, calculation methods other than the configuration of the parameter setting unit 15 shown in FIG. 2 are possible, but it is clear that the effects are the same.

In the above description, the control parameters of all the current control systems for the d-axis, q-axis, and field are adjusted according to the operating conditions. However, the parameters are adjusted only for some control systems that require a response. Obviously, it may be performed, and the necessary effect can be obtained.
Further, in the above description, the effect of the resistance change is not dealt with, but the resistance change is estimated by detecting the temperature of the synchronous machine 1, and the reference time constant of Equation (9) is calculated based on the estimated resistance value. By doing so, it becomes possible to correct the change in the integration time constant due to the resistance change.
In the above description, the command value of each current is input to the inductance coefficient generator. However, it goes without saying that the same effect can be obtained by using the detected value of each current instead.
As described above, according to the first embodiment of the present invention, the current control responsiveness of each winding can be kept the same even when the operating state changes, and there is an effect that stable control becomes possible.

Embodiment 2. FIG.
Next, the second embodiment will be described with reference to FIGS. Generally, in a wound field type synchronous machine, the d-axis and the field axis are in the same electrical angle phase direction, so they are very strongly coupled, and the effects of the d-axis current and field current on magnetic saturation are almost equivalent. It may be good to see. FIG. 3 shows a vector diagram (during power factor 1 operation) on the d and q axes of the wound field type synchronous machine. The d-axis current and the field current flow so as to cancel each other in opposite directions. On the other hand, the q-axis current flows in a direction orthogonal thereto.
From the above characteristics, when modeling the change in inductance, it is also effective to perform modeling using the sum of these, without considering the d-axis current and the field current as independent factors. Specifically, the inductance L is considered as the following formula (10) instead of the formula (6). When such modeling is performed, the number of variables is reduced, so that the number of measurement data necessary for creating the model is reduced, the modeling work is facilitated, and the amount of calculation in the parameter setting unit 15 is reduced. Decrease. In the equation (10), the field current needs to be converted to equivalent to the stator, and is converted by multiplying the turn ratio n.

  Accordingly, the corresponding reference inductance L0 is expressed by Expression (11).

FIG. 4 shows the configuration of the parameter setting unit 15 corresponding to the above inductance change model. The d-axis current command and the field current command from the host control system (not shown) are added by the fourth adder 25, and the result and the q-axis current command are generated by the d-axis inductance coefficient generator 16 and the q-axis inductance coefficient generation. And the field inductance coefficient generator 18. Each of the inductance coefficient generators 16, 17, and 18 performs calculation corresponding to Equation (11) for each of the d-axis, q-axis, and field inductances, and outputs the inductance coefficient in the current operating state of the synchronous machine 1. . The subsequent operation is the same as in FIG.
In the case of the second embodiment, the inductance characteristic may be stored and calculated in the form of data such as a table regardless of the mathematical expression. In particular, when a table is used, data is greatly reduced as compared with the first embodiment.
As in the first embodiment, the parameter may be adjusted only with a part of the current control system that requires a response, and it is clear that the necessary effect can be obtained.
As described above, according to the second embodiment of the present invention, there is an effect that it is possible to realize an inductance modeling for keeping the current control responsiveness of each winding the same with less data and an operation amount.

  Embodiments 1 and 2 of the present invention can be used for a control device for a winding field type synchronous machine.

It is a block diagram which shows the control apparatus of the winding field type synchronous machine of Embodiment 1 of this invention. It is a figure which shows the detail of the process by the parameter setting device of the control apparatus of Embodiment 1 of this invention. It is a figure which shows the vector on d and q axis | shafts of the winding field type | mold synchronous machine of Embodiment 2 of this invention. It is a figure which shows the detail of the process by the parameter setting device of the control apparatus of Embodiment 2 of this invention.

Explanation of symbols

1 Synchronous machine, 2 Three-phase inverter, 3 Single-phase amplifier,
15, 15a Parameter setter, 16 d-axis inductance coefficient generator,
17 q-axis inductance coefficient generator, 18 field inductance coefficient generator,
100 Control device.

Claims (3)

A control device for a winding field type synchronous machine having a multi-phase inverter connected to a stator winding and a single-phase amplifier connected to a field winding,
A stator current control system that controls the d-axis current and q-axis current of the stator winding to drive the multiphase inverter, and a current control of the field winding to drive the single-phase amplifier. A field current control system; and a parameter setter for setting control parameters of the stator and field current control system. The parameter setter includes the stator and field assuming the operating state of the synchronous machine. In addition to storing reference control parameters for the current control system, calculation is performed by inputting current command values to the d-axis, q-axis and field winding of the stator winding from the host control system, and the calculation result is A control apparatus for a wound field type synchronous machine, wherein the stored reference control parameters are respectively multiplied and output to the stator current control system and the field current control system, respectively. The parameter setter is provided with d-axis, q-axis, and field inductance coefficient generators, and the stored reference control parameter is a d-axis, q-axis, and field reference inductance, 2. The winding according to claim 1, wherein in the calculation, a current command value from the host control system is input to each of the inductance coefficient generators to obtain d-axis, q-axis, and field inductance coefficients. Control device for wire field synchronous machine. The parameter setter is provided with an adder. The adder adds the d-axis and field current command value of the host control system, and the addition result is the d-axis, q-axis and field. The q-axis current command value is input to the q-axis inductance coefficient generator, and the calculation is performed by each of the inductance coefficient generators for the d-axis, the q-axis, and the field. The coil field synchronous machine control device according to claim 2, wherein an inductance coefficient of the winding field synchronous machine is obtained.

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