JP5276688B2 - Synchronous machine controller - Google Patents

Description

  The present invention relates to a control device for a synchronous machine provided with power conversion means for rotationally driving the synchronous machine.

  A synchronous machine such as a permanent magnet synchronous motor having a permanent magnet in the rotor or a reluctance motor that generates torque using the magnetic saliency of the rotor is controlled by a synchronous machine control device having power conversion means such as an inverter. Conventionally, it has been widely performed to control the armature current vector in a fixed phase direction with respect to the rotor. For example, in a conventional permanent magnet synchronous machine, the armature current vector is controlled in a direction orthogonal to the permanent magnet magnetic flux axis of the rotor, and the absolute value of the armature current vector is controlled in proportion to the desired torque.

  In the reluctance motor, the absolute value of the armature current vector and the generated torque are not proportional, and it is known that high-accuracy torque control is difficult with the conventional control method. Further, when the rotational speed of the permanent magnet synchronous motor increases, the armature voltage increases due to the induced voltage due to the permanent magnet magnetic flux, and this induced voltage exceeds the voltage that can be output by the power conversion means such as an inverter. In order to prevent this, a weak flux control is performed in which a negative armature current vector called a weak current is generated in the permanent magnet magnetic flux axis direction to reduce the armature linkage magnetic flux. However, since the armature voltage changes if the generated torque is different even if the weakening current is the same, it is difficult for the conventional control method to control the armature voltage to a desired value with respect to the varying torque.

  As an example of such a synchronous machine control device, a torque current calculator that calculates a torque current command that is a torque component of an armature current command from a torque command and a magnetic flux command, the armature current is a current limit value of the power converter. A torque current limit generator that generates a magnetizing current command that is a magnetization component of the armature current command and a torque current command maximum value that can be generated based on the current limit value so as not to exceed, based on the torque current command maximum value A torque current command generator comprising three components of a limiter for limiting the torque current command, a magnetic flux command generator for calculating a magnetic flux command based on the torque current command from the torque current command generator, A magnetic flux calculator for calculating the armature linkage flux based on the armature current or the armature current and the armature voltage of the machine, and the flux command and the armature linkage flux match There is provided a flux controller for inputting the torque current command generator creating a sea urchin magnetizing current command. This considers the limit of the output current of the power converter by calculating the torque current command while referring to the magnetic flux command and the magnetization current command, and calculates the magnetic flux command while referring to the torque current command. Therefore, it is possible to generate a suitable magnetic flux command reflecting the variation of the torque current command due to the output current limitation. (For example, Patent Document 1)

  As another example of a similar control device, estimation by applying a position sensorless control method for controlling a synchronous machine without using a rotor position from a synchronous machine position detector (rotation angle sensor) or without using a position detector. A speed calculator for calculating the rotational speed based on the rotor position, a magnetic flux estimator for calculating the magnetic flux absolute value and the magnetic flux phase from the rotational speed from the speed calculator and the voltage command to the inverter, and the current of the synchronous machine A coordinate converter that calculates a torque current feedback value from the detected current value from the detection means (current sensor) and the magnetic flux phase; a current command calculator that calculates a torque current command from the torque command and the magnetic flux absolute value; and a torque current Some include a current controller that controls the output voltage of the inverter so that the feedback value matches the torque current command. This is because accurate torque control is achieved by directly controlling the torque current, and the current value can be monitored by using the motor current as the control target, while making full use of the power converter's capabilities. Accurate torque control is possible. (For example, Patent Document 2)

As another example of a similar control device, current detection means for detecting the current of the synchronous machine, and rotating biaxial coordinates (hereinafter referred to as dq axes) for rotating the current obtained from the current detection means at an angular frequency Obtained from the current controller, the coordinate converter for converting the coordinates to the current above, the current controller for outputting the voltage command on the dq axis so that the current on the dq axis follows the current command on the dq axis, and a coordinate converter that converts the voltage command on the dq axis into a three-phase voltage command, an angular frequency, an estimated current of the synchronous motor, an estimated rotor magnetic flux based on the current on the dq axis and the voltage command on the dq axis, Some include an adaptive observer (adaptive observation means) that calculates an estimated rotational speed and an inverter that applies a voltage to the synchronous machine based on a voltage command.
This makes it possible to drive the synchronous machine without using a position detector. (For example, Patent Documents 3 and 4)

Japanese Patent No. 4531751 (FIG. 1 and its description) Japanese Unexamined Patent Publication No. 2007-143351 (FIGS. 1 and 6 and explanation thereof) International Publication No. WO2002 / 091558 (FIGS. 1 and 6 and explanation thereof) International Publication No. WO2010 / 109528 (FIGS. 5 and 8 and explanation thereof)

  In Patent Documents 1 and 2, in order to perform proportional-integral control (PI control) based on an error between a desired current command and the detected current of the synchronous machine, the synchronous machine current follows the desired current command. It is assumed that current feedback control is performed by a current controller such as obtaining a voltage command. Although current feedback control is suitable for causing the current of the synchronous machine to follow a desired current command, the power of an inverter or the like is used with respect to the electrical angular frequency (rotational speed) of the synchronous machine as in high-speed driving. When the switching frequency of the switching element of the power conversion means for one cycle of AC voltage applied to each phase of the synchronous machine decreases, such as when the ratio of the carrier frequency of the conversion means is small, the current of the synchronous machine follows the desired current command. Therefore, it is difficult to update the voltage command necessary for this. Therefore, when performing current feedback control, there is a possibility that the current control response may be reduced or the current of the synchronous machine may be disturbed. In addition, in the case of Patent Document 1, when current feedback control is disabled, the magnetic flux control does not perform a desired operation, and it is difficult to follow the magnetic flux command in which the armature linkage magnetic flux of the synchronous machine is suitably calculated. Therefore, there is a possibility that a desired torque cannot be output.

  In Patent Documents 3 and 4, a current controller is configured on the dq axis, and the d axis is used when driving a reluctance motor using reluctance torque or driving a synchronous machine at high speed. When a control method that positively uses a current in the direction (hereinafter referred to as a d-axis current) is applied, there is a problem that the magnitude of the armature current and the generated torque are not proportional and the controllability deteriorates. It is desirable that the current control system or the voltage command generation system be configured so that torque and magnetic flux can be independently operated as in Patent Document 2.

The present invention has been made in view of the above circumstances, and aims to achieve this.
The present invention has been made in order to solve such a problem. In an operation condition in which current feedback control can be performed, a current control system that can operate torque and magnetic flux independently is configured, and The magnetic flux is controlled so as to follow a suitable magnetic flux command corresponding to the current, and the current ratio such that the ratio of the carrier frequency of the power conversion means to the electrical angular frequency (rotational speed) of the synchronous machine is small, such as during high-speed driving. An object of the present invention is to provide a synchronous machine control device capable of improving torque command generation and followability to a torque command even under operating conditions in which feedback control is difficult.

A synchronous machine control device according to the present invention includes a torque current command generator that calculates a torque current command that is a torque component of a current command from a torque command and an armature linkage flux of the synchronous machine, and a rotational speed of the synchronous machine. A first voltage command generator that generates a first voltage command from the armature flux linkage and the torque current command ; a magnetization current command that is a magnetization component of the current command; the torque current command; and the synchronous machine the results of the output current and performs feedback control based on, is composed of a second voltage command generator for generating a second voltage command, said second effective output voltage command generator disable is switched And a voltage command generator that outputs a voltage command by adding together the output of the first voltage command generator, and a power that applies a voltage to the synchronous machine based on a voltage command that is an output of the voltage command generator Conversion means A magnetic flux command generator that calculates a magnetic flux command based on the torque current command and the rotational speed of the synchronous machine, and an estimated armature flux linkage of the synchronous machine based on the output current of the synchronous machine and the voltage command And a magnetic flux calculator for estimating the rotation speed and a current detection means for detecting an output current of the synchronous machine, wherein the magnetic flux command generation is performed according to an operating condition of the synchronous machine. The armature interlinkage magnetic flux is output by switching the magnetic flux command output from the controller and the estimated armature interlinkage magnetic flux output from the magnetic flux calculator, and the output of the second voltage command generator is effective. A magnetic flux setting device for outputting a signal for switching invalidity; and a magnetizing current command generator for generating the magnetizing current command based on a difference between the magnetic flux command and the estimated armature linkage flux. What to do That.

A synchronous machine control device according to the present invention includes a torque current command generator that calculates a torque current command that is a torque component of a current command from a torque command and an armature linkage magnetic flux of the synchronous machine, and a rotation of the synchronous machine A first voltage command generator that generates a first voltage command from the speed, the armature flux linkage, and the torque current command ; a magnetization current command that is a magnetization component of the current command; the torque current command; performs feedback control based on the output current of the synchronous machine, is composed of a second voltage command generator for generating a second voltage command, valid or invalid switching of the output of the second voltage command generator 32 A voltage command generator that outputs a voltage command by adding the obtained result and the output of the first voltage command generator, and a voltage is applied to the synchronous machine based on the voltage command that is the output of the voltage command generator. Applied electricity Conversion means, a magnetic flux command generator for calculating a magnetic flux command based on the torque current command and the rotational speed of the synchronous machine, and an estimated armature of the synchronous machine based on the output current of the synchronous machine and the voltage command Based on the magnetic flux calculator for estimating the flux linkage, the current detection means for detecting the output current of the synchronous machine, the position detector for detecting the rotor position of the synchronous machine, and the rotor position of the synchronous machine A synchronous machine control device comprising a speed calculator for calculating the rotational speed of the synchronous machine, wherein the magnetic flux command and the magnetic flux calculator output from the magnetic flux command generator according to operating conditions of the synchronous machine Switching the estimated armature flux linkage output from the armature flux linkage, and outputting a signal for switching the output of the second voltage command generator valid and invalid, and Magnetic flux command and the above And it is characterized in that it comprises a magnetizing current command generator for generating a magnetizing current command based on the difference between the constant-armature flux linkage.

  According to the present invention, a control system capable of independently operating the torque and magnetic flux of the synchronous machine regardless of the presence or absence of a position detector that detects the rotor position of the synchronous machine is configured. Under operating conditions in which current feedback control is possible, magnetic flux feedback control is performed so as to follow a suitable magnetic flux command according to the operation purpose, and an error with the actual armature linkage flux is small and a stable value can be obtained from the estimated value. A torque command and a voltage command are generated based on the magnetic flux command value. Also, under the operating conditions where current feedback control is difficult, magnetic flux feedback control cannot be performed by the magnetizing current command generator, so the command is based on the estimated armature linkage flux close to the actual armature linkage flux. Is generated. By adopting such a configuration, the controllability is excellent, and a remarkable effect that is not possible in the past, such as enabling output of a torque following a desired torque command, is achieved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Embodiment 1 of this invention, and is a block diagram which shows an example of the synchronous machine control system containing the synchronous machine 1 and a synchronous machine control apparatus. It is the figure which showed the definition of phase (rho), and the relationship between phase (rho) and torque. It is a vector diagram of a synchronous machine (mainly a permanent magnet synchronous machine). It is a figure which shows Embodiment 1 of this invention, and is a block diagram which shows an example of the voltage command generator 3. FIG. It is a figure which shows Embodiment 1 of this invention, and is a block diagram which shows an example of the magnetic flux calculating unit 6. FIG. It is a figure which shows Embodiment 1 of this invention, and is a block diagram which shows an example of the magnetic flux setting device 8. FIG. It is a figure which shows Embodiment 2 of this invention, and is a block diagram which shows the other example of the synchronous machine control system containing the synchronous machine 1 and a synchronous machine control apparatus. It is a figure which shows Embodiment 2 of this invention, and is a figure which shows an example of a structure of the magnetic flux calculating unit 6a. It is a figure which shows Embodiment 2 of this invention, and is a figure which shows an example of a structure of the magnetic flux calculator 6b different from the magnetic flux calculator 6a. It is a figure which shows Embodiment 2 of this invention, and is a block diagram which shows the example of the synchronous machine control system including the synchronous machine 1 and synchronous machine control apparatus at the time of not using the current detection means 7 (it cannot use). It is a figure which shows Embodiment 2 of this invention, and is a figure which shows an example of a structure of the magnetic flux setting device 8a different from the magnetic flux setting device 8. FIG.

Embodiment 1 FIG.
FIG. 1 shows a synchronous machine control system including a synchronous machine 1 and a synchronous machine control device according to Embodiment 1 of the present invention.
Hereinafter, the configuration of the synchronous machine control device for driving the synchronous machine 1 and the function of the components in the first embodiment of the present invention will be described.

  First, the power conversion means 4 including the inverter is connected to the armature winding of the synchronous machine 1, and the power conversion means 4 applies a voltage to the synchronous machine 1 based on a voltage command obtained by the following configuration. The synchronous machine 1 is driven. As a result, an output current is generated in the armature winding of the synchronous machine 1.

  The current in the armature winding, which is the output current of the synchronous machine 1, is detected by current detection means 7 including a current sensor. In addition, when the synchronous machine 1 is a three-phase rotating machine, the current detecting means 7 is configured to detect all phases of the three-phase output current of the synchronous machine 1 or one phase (for example, w phase). The output current iw of the two phases may be obtained from the relationship of iw = −iu−iv using the detected output currents iu and iv of the two phases, and the output current of the two phases may be detected.

  The magnetic flux calculator 6 determines the rotational speed ω of the synchronous machine 1 based on the output currents iu, iv, iw of the synchronous machine 1 detected by the current detection means 7 and the three-phase voltage commands Vu *, Vv *, Vw *. The rotor position θ, (estimated) armature flux linkage absolute value | Φ |, and (estimated) armature flux linkage phase ∠Φ are estimated. The detailed configuration of the magnetic flux calculator 6 will be described later.

  In the following description, the (estimated) armature flux linkage absolute value | Φ | and the (estimated) armature flux linkage phase ∠Φ are collectively referred to as “estimated armature flux linkage”.

  In the present invention, the armature current is controlled on the two axes of the direction of the armature flux linkage Φ (γ axis) and the orthogonal direction (δ axis) in the same manner as in Patent Documents 1 and 2. For this reason, the output currents iu, iv, iw of the synchronous machine 1 are converted into currents iγ, iδ on the γδ axis in the coordinate converter 10b. (The calculation formula in the coordinate converter will be described later.) The γ-axis current iγ obtained by the conversion is a magnetization current that is a magnetization component of the synchronous machine 1, and the δ-axis current iδ is a torque current that contributes to the torque generation of the synchronous machine 1. Each corresponds.

  The voltage command generator 3 includes voltage commands vγ *, γδ on the γδ axis so that currents iγ, iδ on the γδ axis coincide with desired current commands iγ *, iδ * input from outside the voltage command generator 3. Outputs vδ *. In Patent Documents 1 and 2, it is assumed that a current controller is applied to the voltage command generator 3 and current feedback control is performed. Although current feedback control is suitable for causing the output current of the synchronous machine 1 to follow a desired current command, power conversion is performed with respect to the electrical angular frequency (rotational speed) of the synchronous machine as in high-speed driving. When the number of times of switching of the switching element of the power conversion means with respect to one cycle of AC voltage applied to each phase of the synchronous machine is reduced, such as when the ratio of the carrier frequency of the means 4 is small, the current of the synchronous machine 1 is set to a desired current command. It becomes difficult to update the voltage command necessary for the tracking. Therefore, there are not a few operating conditions that make it difficult to cause the output current of the synchronous machine 1 to follow a desired current command.

  In the present invention, in order to deal with such an operating condition that makes current feedback control difficult, the voltage command generator 3 disables the current feedback control under the operating condition in which current feedback control is difficult, and the first voltage command Only voltage is generated and voltage feedforward control is performed.

  The detailed configuration of the voltage command generator 3 and the switching between valid / invalid of current feedback control will be described later. The voltage commands vγ * and vδ * on the γδ axis output from the voltage command generator 3 are converted into the three-phase voltage commands Vu *, Vv * and Vw * by the coordinate converter 10a, and then sent to the power conversion means 4. The power conversion means 4 outputs the three-phase voltages Vu, Vv, Vw to the synchronous machine 1 based on the three-phase voltage commands Vu *, Vv *, Vw *.

  On the other hand, the torque current command generator 2 determines the γ-axis current (magnetization current) command iγ * and the armature linkage magnetic flux Φs (Φs) of the synchronous machine 1 from the torque command τ * given from the outside of the synchronous machine control device. The δ-axis current (torque current) command iδ * is calculated with reference to the details later.

  The magnetic flux command generator 5 calculates the magnetic flux command Φ * from the δ-axis current command iδ * while referring to the rotational speed ω obtained by the magnetic flux calculator 6.

  The adder 51a calculates the magnetic flux error ΔΦ by subtracting the (estimated) armature flux linkage absolute value | Φ | output from the magnetic flux calculator 6 from the magnetic flux command Φ *, and the magnetizing current command generator 9 In order to adjust the magnetic flux error ΔΦ to zero, a γ-axis current command iγ * is generated based on the magnetic flux error ΔΦ.

  Details of the torque current command generator 2, the magnetic flux command generator 5, the magnetization current command generator 9, and the magnetic flux calculator 6 will be described in the following order.

The torque current command generator 2 generates the δ-axis current command iδ * based on the following concept. If the control is performed so that the armature flux linkage and the γ-axis coincide with each other, the relationship of the formula (1) exists between the torque τ generated by the synchronous machine 1 and the δ-axis current iδ.

Therefore, the torque current command generator 2 first calculates the δ-axis current command iδ * of the equation (2) by the equation in which the torque τ of the equation (1) is replaced with the torque command τ *.

However, the current that can be passed through the synchronous machine 1 is often limited to the current limit value imax that depends on the specifications of the power conversion means 4 and the δ-axis current based on the current limit value imax and the γ-axis current command iγ *. The command iδ * may be limited. When this restriction is applied, the upper limit value iδ * max of the δ-axis current command iδ * is expressed by equation (3).

  The magnetic flux command generator 5 outputs a suitable magnetic flux command Φ * with respect to the input δ-axis current command iδ *. The concept will be described below with reference to FIGS.

  A permanent magnet synchronous machine having a permanent magnet in the rotor, a reluctance motor that generates torque using the magnetic saliency of the rotor, and a field winding having a field winding having a constant field flux In the linear synchronous machine, when the phase ρ from the (rotor) d-axis of the current vector i having a constant absolute value is changed as shown in FIG. 2, the torque becomes maximum as shown in FIG. There exists a phase. In general, when the synchronous machine 1 has field means such as permanent magnets or field windings in the rotor, the N-pole direction of the magnetic flux generated by the field means is d-axis, and the axis perpendicular to this is q The following explanation follows this.

  As an example, in the case of a motor having a reverse saliency with a q-axis inductance larger than the d-axis, such as a permanent magnet synchronous machine, as shown in FIG. 3, the torque at a certain angle where the phase ρ of the current vector is larger than 90 °. Is maximized. If there is no magnetic saturation of the iron core, this suitable current phase ρ is constant regardless of the magnitude of the armature current. However, in the actual machine, since the inductance changes due to magnetic saturation, the preferred current phase ρ is reluctance. Due to the torque, it varies depending on the magnitude of the armature current. When the armature current is small, magnetic saturation does not occur, and when the phase ρ is larger than 90 ° (for example, about 110 °), the torque increases under the condition that the current vector i is a constant absolute value. When the armature current is increased and the condition of the current vector absolute value is changed, magnetic saturation occurs mainly in the q-axis direction in which the current flows, and the difference between the q-axis inductance Lq and the d-axis inductance Ld becomes smaller. For this reason, there is a case where the torque becomes larger when the phase ρ is made smaller (for example, about 100 °).

  Here, the relationship between the armature current and the magnetic flux in this preferable current phase state will be considered.

  FIG. 3 shows a vector diagram of a synchronous machine (mainly a permanent magnet synchronous machine). The armature linkage magnetic flux Φs is a combination of an armature reaction magnetic flux Φa generated by a current vector i and a field (permanent magnet) magnetic flux Φm. If the direction perpendicular to the armature flux linkage Φs is the δ-axis, the δ-axis direction component of the current vector i is the δ-axis current iδ.

  Therefore, if the current vector i comprising the armature current absolute value and the preferred current phase ρ determined from the absolute value is determined, the absolute values of the δ-axis current iδ and the armature linkage magnetic flux Φs are uniquely determined. This shows that a one-to-one relationship is established between the δ-axis current iδ and the armature flux linkage absolute value | Φs | under the maximum torque condition. In the determination of the armature flux linkage absolute value | Φs | shown so far, the voltage limit value limited by the specifications of the power conversion means 4 is not considered.

  The magnetic flux command generator 5 obtains the relationship between the δ-axis current iδ and the armature flux linkage absolute value | Φs | based on the above concept, and stores these relationships in the form of mathematical formulas and table data. According to the inputted δ-axis current command iδ *, a suitable magnetic flux command (intermediate value) Φ ** which is a suitable absolute value of the armature linkage flux is output. In the above description, the δ-axis current command iδ * and the magnetic flux command (intermediate value) Φ ** are related so that the generated torque is maximized, but the desired performance depends on the operation purpose and the performance target. When the maximum δ-axis current command iδ * and the magnetic flux command (intermediate value) Φ ** are related, an operation characteristic corresponding to the purpose can be obtained. For example, when the relationship between the δ-axis current command iδ * and the magnetic flux command (intermediate value) Φ ** that maximizes the efficiency is performed, the rotational speed ω of the synchronous machine 1 is set to take into account the influence of iron loss. Referring to FIG. 6, the characteristics can be further improved by adjusting the magnetic flux command (intermediate value) Φ ** when the rotational speed ω increases.

  However, since the magnetic flux command (intermediate value) Φ ** does not consider the voltage limit value limited by the specifications of the power conversion means 4, the synchronous machine 1 is based on the voltage that can be output by the power conversion means 4. The magnetic flux command maximum value corresponding to the rotational speed ω of Φ * max is calculated, and the magnetic flux command (intermediate value) Φ ** is limited to the magnetic flux command maximum value Φ * max. Output.

When the δ-axis current command iδ * is limited based on the current limit value imax and the γ-axis current command iγ * as described above, calculation is circulated between the torque current command generator 2 and the magnetic flux command generator 5. Become. That is, torque command τ * → (torque current command generator 2) → torque current command iδ * → (flux command generator 5) → flux command Φ * → (torque current command generator 9) → torque current command iδ *. In order to determine the torque current command iδ * and the magnetic flux command Φ * for the input torque command τ *, the calculation of the torque current command generator 2 and the magnetic flux command generator 5 is repeated to converge. This makes it difficult to perform arithmetic processing.

  As a countermeasure, when the processing is performed by a microcomputer at a predetermined calculation cycle in an actual device, for example, the previous calculation result (one calculation cycle before) is used as the magnetic flux command Φ * used by the torque current command generator 2. The magnetic flux command generator 5 calculates the current magnetic flux command Φ * based on the δ-axis current command iδ * calculated using the command value, or the magnetic flux command generator 5 filters the value of the magnetic flux command Φ * with an appropriate filter. There is a method for improving the stability of the arithmetic processing by outputting through the network, and it may be applied to an actual apparatus.

  Next, the magnetizing current command generator 9 will be described.

（４）式において、sはラプラス演算子であり、1/sは１回の時間積分を意味する。また、Kfは積分ゲインである。 The magnetizing current command generator 9 generates the γ-axis current command iγ * based on the magnetic flux error ΔΦ in order to adjust the magnetic flux error ΔΦ to 0 as described above. Since the γ-axis current iγ is a magnetization current that is a magnetization component of the synchronous machine 1, the armature flux linkage can be manipulated by the γ-axis current. Specifically, the increase / decrease amount of the magnetizing current and the increase / decrease amount of the armature linkage flux are proportional to each other with the γ-axis inductance Lγ as a proportional coefficient, and a controller for adjusting the magnetic flux error ΔΦ to be 0 An integrator that does not have a direct term is suitable, and a γ-axis current command iγ * is generated by using an integral control calculation such as the equation (4).

In the equation (4), s is a Laplace operator, and 1 / s means one time integration. Kf is an integral gain.

  However, as described above, it is difficult to suppress the magnetic flux error ΔΦ with the current (feedback) control system of the γ-axis current iγ under the operating condition in which the current feedback control is difficult, and the integration of the equation (4) is performed with the magnetic flux error ΔΦ = 0. The computation may be stopped. Alternatively, the γ-axis current command iγ * may be set to zero.

  Next, the voltage command generator 3 will be described.

  FIG. 4 is a configuration diagram of the voltage command generator 3. In the voltage command generator 3 of the present invention, as described above, the current feedback control is invalidated under the operating condition in which the current feedback control is difficult, so that the current feedback control is disabled so as to be able to cope with the operating condition in which the current control is difficult. Only the voltage command is generated and the voltage feedforward control is performed.

In the first voltage command generator 31, (5) based on the current commands iγ *, iδ * on the γδ axis, the rotational speed ω (electrical angular frequency conversion) of the synchronous machine 1, and the armature linkage flux Φs. The first voltage command (voltage feedforward control term) vγ1, vδ1 is generated by the equation.

Kpγは電流制御γ軸比例ゲイン、Kiγは電流制御γ軸積分ゲイン、Kpδは電流制御δ軸比例ゲイン、Kiδは電流制御δ軸積分ゲインである。前記の通り、電流制御が困難となる運転条件では、（６）式の電流フィードバック制御を無効とし、vγ2＝vδ2＝０とする。 In the second voltage command generator 32, based on the deviation between the current commands iγ *, iδ * on the γδ axis and the currents iγ, iδ on the γδ axis (output of the synchronous machine 1) calculated by the adder / subtractor 51c. Proportional integral control (PI control) of equation (6) is performed by the PI controller 33, and second voltage commands (current feedback control terms) vγ2 and vδ2 (on the γδ axis) are generated.

Kpγ is a current control γ-axis proportional gain, Kiγ is a current control γ-axis integral gain, Kpδ is a current control δ-axis proportional gain, and Kiδ is a current control δ-axis integral gain. As described above, under the operating conditions in which current control is difficult, the current feedback control of equation (6) is invalidated and vγ2 = vδ2 = 0.

With respect to the method of invalidating the current feedback control, in the present invention, the validity / invalidity of the current feedback control is determined by the magnetic flux setting unit 8 described later, and the determination result of the validity / invalidity of the control is output as the current control valid / invalid switching flag FL. Then, based on the flag FL, the configuration is such that the output of the second voltage command generator 32 (current feedback control term) included in the voltage command generator 3 is switched by the switch 34a. As shown in FIG. 4, when invalidating the output of the second voltage command generator 32, the switch 34a is switched so that vγ2 = vδ2 = 0.
Of course, the function of determining the validity / invalidity of the current feedback control may be included in the voltage command generator 3 instead of the magnetic flux setter 8.

The adder / subtractor 51b generates (final) voltage commands vγ * and vδ * on the γδ axis, which are outputs of the voltage command generator 3, based on the equation (7).

  Next, the magnetic flux calculator 6 will be described.

  The magnetic flux calculator 6 determines the rotational speed ω of the synchronous machine 1 based on the output currents iu, iv, iw of the synchronous machine 1 detected by the current detection means 7 and the three-phase voltage commands Vu *, Vv *, Vw *. The rotor position θ, (estimated) armature flux linkage absolute value | Φ |, and (estimated) armature flux linkage phase ∠Φ are estimated. FIG. 5 is an example of a configuration diagram of the magnetic flux calculator 6.

  However, the rotor position θ of the synchronous machine 1 refers to an angle in the d-axis direction with respect to an axis based on the u-phase armature winding of the synchronous machine 1, and (estimated) the armature linkage magnetic flux phase ∠ Similarly, Φ indicates the angle of the (estimated) armature flux linkage direction (γ-axis direction) with respect to the axis based on the u-phase armature winding.

  The magnetic flux calculator 6 includes an adaptive observer 20 including a synchronous machine model 21, a deviation amplifier 22, a gain setting unit 23, and a speed estimator 24, an integrator 25, an armature linkage flux converter 26, and a plurality of It consists of a coordinate converter and an adder / subtracter. Note that the configuration of the adaptive observer 20 is the same as that of Patent Documents 3 and 4.

  First, the coordinate converters (10c, 10d) change the output currents iu, iv, iw of the synchronous machine 1 to the currents id, iq on the dq axis based on the rotor position θ, the voltage command vγ *, Three-phase voltage commands Vu *, Vv *, and Vw * obtained by converting the coordinates of vδ * by the coordinate converter 10a are converted into voltage commands Vd * and Vq * on the dq axis based on the rotor position θ. Of course, the voltage command Vγ * and Vδ * on the γδ axis output from the voltage command generator 3 may be directly converted into the voltage commands Vd * and Vq * on the dq axis.

ここで、Ld：ｄ軸方向のインダクタンス（以下、ｄ軸インダクタンスと称す）、Lq：ｑ軸方向のインダクタンス（以下、ｑ軸インダクタンスと称す）、id0：ｄ軸推定電流、iq0：ｑ軸推定電流、f1、f2、f3、f4は後述の（１２）式に基づいて算出する偏差である。 The synchronous machine model 21 has a d-axis estimated current id0 and a q-axis estimated current based on voltage commands Vd * and Vq * on the dq axis, an estimated rotational speed ωr0 described later, and deviations f1, f2, f3, and f4. iq0, d-axis component pds of estimated armature reaction magnetic flux, q-axis component pqs of estimated armature reaction magnetic flux, q-axis component pqr of estimated rotor magnetic flux, and rotational speed (electrical angular frequency) ω are obtained. The arithmetic expressions in the synchronous machine model 21 are expressed by the expressions (8) to (10), and the pds, pqs, and pdr are obtained by integrating both sides of the expression (8). The calculation of equation (9) corresponds to the calculation of the rotational speed (electrical angular frequency) ω so that the q-axis component pqr of the estimated rotor magnetic flux becomes zero, and this is the calculation of the estimated rotor magnetic flux vector. Since it is in agreement with the direction to coincide with the d-axis, the q-axis component pqr of the estimated rotor magnetic flux is zero.

Here, Ld: inductance in the d-axis direction (hereinafter referred to as d-axis inductance), Lq: inductance in the q-axis direction (hereinafter referred to as q-axis inductance), id0: d-axis estimated current, iq0: q-axis estimated current , F1, f2, f3, and f4 are deviations calculated based on the equation (12) described later.

ここで、Kp0：比例ゲイン、Ki0:積分ゲインである。 The adder / subtractor 51d calculates a d-axis current deviation errd obtained by subtracting the d-axis current id from the d-axis estimated current id0 and a q-axis current deviation errq obtained by subtracting the q-axis current iq from the q-axis estimated current iq0. The speed estimator 24 outputs the estimated rotational speed ωr0 by the equation (11) based on the d-axis estimated rotor magnetic flux pdr and the q-axis current deviation errq.

Here, Kp0: proportional gain, Ki0: integral gain.

  The gain setter 23 outputs current deviation amplification gains h11, h12, h21, h22, h31, h32, h41, h42 based on the estimated rotational speed ωr0. These gains (a part of) are known to change in suitable values according to the estimated rotational speed ωr0, and the change in the estimated rotational speed ωr0 so that the pds, pqs, and pdr can be stably obtained in advance. Design in consideration of

  The configuration of the adaptive observer 20 is the same as that of Patent Documents 3 and 4, and the current deviation amplification gains h11, h12, h21, h22, h31, h32, h41, and h42 are based on the Patent Documents 3 and 4. Since the present invention can be suitably implemented even if designed, the details of the design basis and design method of these gains are omitted.

The deviation amplifier 22 amplifies the current deviations errd and errq of each of the dq axes by the current deviation amplification gains h11, h12, h21, h22, h31, h32, h41, h42 based on the equation (12), and deviations f1, f2, Calculate f3 and f4.

  The integrator 25 integrates the rotational speed (electrical angular frequency) ω output from the rotating machine model 21 and outputs the rotor position θ.

  The adaptive observer 20 estimates the rotation speed (electrical angular frequency) ω and the estimated current id0, iq0 and the estimated rotation on the dq axis based on the current id and iq on the dq axis and the coaxial voltage commands Vd * and Vq *. An adaptive observer configured on the dq axis for calculating the child magnetic fluxes pdr and pqr and the estimated rotational speed ωr0. In addition to the observer, a method for configuring an adaptive observer on the stationary two axes, or a state variable with an estimated current Even with a method of configuring an adaptive observer that uses variables other than id0 and iq0, it is possible to construct a rotating machine model 21 having the same function as the model.

The armature flux linkage converter 26 first calculates the components pds and pqs of the estimated armature reaction magnetic flux on the dq axis and the components pdr and pqr (pqr = 0) of the estimated rotor magnetic flux on the dq axis. The d-axis component pd0 and the q-axis component pq0 of the estimated armature flux linkage are calculated based on the equation (13).

From the d-axis component pd0 and the q-axis component pq0 of the estimated armature linkage magnetic flux obtained by the equation (13), based on the equations (14) and (15) (estimated) the absolute value of the armature linkage flux | Φ | And (estimated) armature flux linkage phase ∠Φ is calculated and output.

  Next, the magnetic flux setter 8 that is a feature of the present invention will be described. First, after explaining the outline of the configuration of the magnetic flux setting device 8, the purpose of providing the magnetic flux setting device 8 in the synchronous machine control device and the operating condition determination unit 80 that is a component of the magnetic flux setting device 8 will be described. To do.

FIG. 6 is a configuration diagram of the magnetic flux setter 8.
As described above, in an operation condition where current feedback control is difficult, in order to perform only the voltage feedforward control with the current feedback control disabled, first, the current feedback control is enabled / disabled based on the operation conditions described later. The condition is determined by the condition determining unit 80, and the determination result is output as the current control valid / invalid switching flag FL. In addition, the magnetic flux output from the magnetic flux command generator 5 as a value to be used as the armature interlinkage magnetic flux Φs of the synchronous machine 1 in the calculation of another control configuration based on the determination result of the validity of the control. The command Φ * and the (estimated) armature flux linkage absolute value | Φ | output from the magnetic flux calculator 6 are switched and output.

  As a method for realizing these operations, in FIG. 6, according to the determination result in the operating condition determination unit 80, the switch 34b switches the value used as the armature linkage magnetic flux Φs of the synchronous machine 1, An example is shown in which the current control valid / invalid switching flag FL is switched at 34c. However, the switches 34b and 34c are examples of means for switching the output in accordance with the determination result in the operating condition determination unit 80, and it is not always necessary to be concerned with the switch as the switching means, and the switching operation described above is realized. Other means other than the switch to be used may be used.

  The above is the outline of the configuration of the magnetic flux setter 8. Next, the purpose of providing the magnetic flux setter 8 will be described.

  When the current feedback control is valid, the magnetic flux error ΔΦ is controlled to be 0 by the operation of the current feedback control (that is, magnetic flux feedback control) based on the output γ-axis current command iγ * of the magnetizing current command generator 9. The magnetic flux command Φ *, which has a small error from the actual armature interlinkage magnetic flux and is more stable than the (estimated) armature interlinkage magnetic flux | Φ | The value of the armature interlinkage magnetic flux Φs of the synchronous machine 1 used in FIG. However, when the current feedback control is disabled, it is difficult to suppress the flux error ΔΦ by the current (feedback) control system of the γ-axis current iγ, and an error occurs between the flux command Φ * and the actual armature linkage flux. there is a possibility. Under such conditions, the (estimated) armature linkage magnetic flux absolute value | Φ | is suitable as the value of the armature linkage flux Φs of the synchronous machine 1 used in the calculation of another control configuration from the magnetic flux command Φ *. Become.

  From this, the δ-axis current command i δ * generation based on the formula (2) in the torque current command generator 2 and the first formula based on the formula (5) in the first voltage command generator 31 of the voltage command generator 3. When generating the voltage command (voltage feedforward control term) vγ1, vδ1 of 1 (on the γδ axis), the value of the armature linkage magnetic flux Φs of the synchronous machine 1 used for the generation is set according to the above-mentioned suitable condition. It is desirable to switch between the magnetic flux command Φ * and the (estimated) armature flux linkage absolute value | Φ |, and the magnetic flux setter 8 is for realizing this switching operation.

  Moreover, when the current feedback control is invalid (estimated), the armature linkage magnetic flux absolute value | Φ | is used as the value of the armature linkage flux Φs of the synchronous machine 1 in the calculation of another control configuration.

First, consider the operation of the adaptive observer 20 when the current feedback control is disabled. When the current feedback control is invalid, vγ * = vγ1, vδ * = vδ1, and (16) between the voltage commands Vγ * and Vδ * on the γδ axis and the voltage commands Vd * and Vq * on the dq axis. Since there is a relationship between the equations, the voltage commands Vd * and Vq * on the dq axis are expressed by Equation (17), and the arithmetic expressions of the adaptive observer 20 in the steady state are Equations (18) and (19).

  In the equation (17), the subscript * is a command value and the subscript ob is a set value used for adaptive observer calculation. (For example, Ldob means a set value of Ld used for adaptive observer calculation.)

In the equations (18) and (19), it is assumed that the rotational speed ω is sufficiently high when the current feedback control is invalid. Under this assumption, the influence of the generated voltage on the stator winding resistance can be regarded as very small (that is, Rob≈0). Further, assuming that it is in a steady state, the differential term (d / dt term) is 0 and can be regarded as ω≈ωr0. .

Here, assuming that the error of the (estimated) armature linkage magnetic flux | Φ | relative to the armature linkage flux Φs used when calculating the voltage commands Vγ * and Vδ * on the γδ axis is Φserr, (13) From the relationship between the equation and the equation (15), the equation (22) and the equation (23) are established.

When the relationship between the equations (20) to (23) is arranged, the equation (24) is obtained.

  In the equation (25), when Φserr ≠ 0, that is, Φs ≠ | Φ |, since id0 ≠ id and iq0 ≠ iq, a current estimation error occurs in the adaptive observer. Therefore, when current feedback control is disabled, Φs = | Φ |, that is, the armature linkage flux Φs used to calculate the voltage commands Vγ * and Vδ * on the γδ axis (estimated) armature linkage flux absolute value It can be seen that it is desirable to use | Φ |.

Further, consider the operation of the adaptive observer 20 when parameter variations such as inductance occur. The equation of state of the synchronous machine 1 having the field (permanent magnet) magnetic flux Φm is expressed as follows: the d-axis component Φds of the actual armature reaction magnetic flux, the q-axis component Φqs of the actual armature reaction magnetic flux, and the actual voltages Vd and Vq on the dq axis. This is expressed using equation (25).

If a steady state is considered and approximated similarly to the case of the observer, equation (27) is obtained. (R = 0, differential term (d / dt term): 0)

Ldob−Ld＝ΔLd（適応オブザーバ演算に使用するLdの設定値とLd真値との誤差相当）とすると、二次側d軸磁束推定値pdrは（３１）式となる。

また、Lqob−Lq＝ΔLq（適応オブザーバ演算に使用するLqの設定値とLq真値との誤差相当）とすると、０＝ΔLq・Iqとなることがわかる。 Here, it is assumed that the actual voltages Vd and Vq on the dq axis are output according to the voltage commands Vd * and Vq * on the dq axis, and the current estimation error in the equations (27) and (20) Equations (29) and (30) can be derived from the approximate equation (28) of the steady state of the adaptive observer when there is no (id0 = id, iq0 = iq).

If Ldob−Ld = ΔLd (corresponding to an error between the set value of Ld used for adaptive observer calculation and the true value of Ld), the secondary-side d-axis magnetic flux estimated value pdr is expressed by equation (31).

Further, when Lqob−Lq = ΔLq (corresponding to an error between the set value of Lq used for adaptive observer calculation and the true value of Lq), it can be seen that 0 = ΔLq · Iq.

On the other hand, the armature linkage magnetic flux Φs is a value on the γ-axis, and as described above, Φs = | Φ | is selected when the current feedback control is invalid. Further, from the relationship of the equations (13), (19), and (31), the d-axis component of the armature flux linkage (estimated) when there is no current estimation error (id0 = id, iq0 = iq) pd0 and q-axis component pq0 are given by equation (32).

The value of | Φ | used as the value of the armature interlinkage magnetic flux Φs when the current feedback control is invalid is a value obtained by substituting the expression (32) into the expression (14). At this time, since the torque command τ * is generated based on the value of (estimated) armature linkage magnetic flux | Φ |, that is, the values of pd0 and pq0 in (32), the torque τ generated by the synchronous machine 1 and The amount corresponding to the torque command τ * is expressed by equation (33). From equation (33), it can be seen that there is no influence of errors ΔLd and ΔLq between the set values of Ld and Lq used for adaptive observer computation and the true values of Ld and Lq.

  Therefore, when the current feedback control is invalid (estimated), the armature flux linkage absolute value | Φ | is calculated using the δ-axis current command iδ * generation calculation and the γδ-axis voltage command (voltage feedforward control term) vγ1 and vδ1 generation calculation. If the armature flux linkage Φs of the synchronous machine 1 is used, the controllability is not affected by the errors ΔLd and ΔLq between the set values of Ld and Lq used for adaptive observer calculation and the true values of Ld and Lq. And a torque that follows a desired torque command can be output.

  Next, a method for determining the validity / invalidity of the current feedback control based on the operation condition in the operation condition determination unit 80 which is a component of the magnetic flux setter 8 will be described.

First, as a suitable determination criterion, there is a rotational speed ω of the synchronous machine 1.
As shown in FIG. 6, the rotational speed (electrical angular frequency) ω of the synchronous machine 1 is input to the operating condition determination unit 80. As the rotational speed ω of the synchronous machine 1 increases, the frequency of the three-phase voltages Vu, Vv, and Vw applied to the synchronous machine 1 by the power conversion means 4 also increases, so that the current of the synchronous machine follows the desired current command. In order to perform good current feedback control, it is necessary to increase the carrier frequency of the power conversion unit 4 and increase the number of switching times of the switching element of the power conversion unit 4 to perform fine current control.
However, since the upper limit of the carrier frequency of the power conversion means 4 depends on the characteristics of the switching element of the power conversion means 4, the current feedback control is performed within the carrier frequency range set in consideration of the characteristics of the switching element. Is determined in advance, and when the rotational speed ω of the synchronous machine 1 exceeds the speed range, it is determined that the current feedback control is invalidated.

  In this way, by setting the operating condition of the synchronous machine for switching the presence / absence of the current feedback control to the rotational speed ω of the synchronous machine 1, the current feedback control is appropriately invalidated at the time of high speed rotation where current feedback control becomes difficult. The effect that can be obtained.

  Another suitable criterion is the ratio of the carrier frequency of the power conversion means 4 to the rotational speed ω of the synchronous machine 1. As shown in FIG. 6, the point that the rotational speed ω of the synchronous machine 1 is input to the operating condition determination unit 80 is the same as the case where the determination is made based on the rotational speed ω of the synchronous machine 1. Consider the carrier frequency of the power conversion means 4.

  Even under the same rotational speed condition, the switching frequency of the switching element of the power conversion means for one cycle of the AC voltage applied to each phase of the synchronous machine varies depending on the setting of the carrier frequency of the power conversion means 4, and thus the stability of the current feedback control Changes. Therefore, when the setting of the carrier frequency of the power conversion means 4 changes sequentially, the current is based not only on the rotation speed ω of the synchronous machine 1 but also on the ratio of the carrier frequency of the power conversion means 4 to the rotation speed ω of the synchronous machine 1. It is desirable to determine whether the feedback control is valid or invalid. In this way, when the carrier frequency of the power conversion means 4 is large, the speed at which the current feedback control is switched between valid and invalid is increased. Conversely, when the carrier frequency of the power conversion means 4 is small, the current feedback control It is possible to reduce the speed for switching between valid and invalid.

  As described above, by setting the operating condition of the synchronous machine for switching the presence / absence of the current feedback control based on the ratio of the carrier frequency of the power conversion means to the rotational speed of the synchronous machine, the current feedback control becomes difficult at high speed rotation. In this case, the current feedback control can be appropriately invalidated, and an effect of appropriately changing the rotation speed for switching the validity / invalidity of the current feedback control according to the setting of the carrier frequency can be obtained.

  Another suitable criterion is the ratio of the processing frequency of the synchronous machine control device to the rotational speed ω of the synchronous machine 1. The point that the rotational speed ω of the synchronous machine 1 is input to the operating condition determination unit 80 is the same as the case where the determination is made based on the rotational speed ω of the synchronous machine 1, but in the determination, the arithmetic processing of the synchronous machine control device The frequency, specifically, the arithmetic processing cycle (reciprocal number) of the microcomputer that performs arithmetic processing related to the synchronous machine control device is taken into consideration.

  Normally, a microcomputer that performs arithmetic processing related to a synchronous machine control device performs control arithmetic processing at every arithmetic processing cycle that is appropriately set based on the specifications of the microcomputer and the arithmetic processing load, and results of arithmetic operations such as commands in control Is output. The update cycle of the voltage command generated by the voltage command generator 3 in the control of the synchronous machine 1 also depends on the calculation processing cycle of the microcomputer. Therefore, the update cycle of the voltage command changes according to the calculation processing cycle of the microcomputer that performs the calculation processing related to the synchronous machine control device (the reciprocal is the calculation processing frequency of the synchronous machine control device), and the shorter the update cycle, Fine current control can be performed, and the upper limit of the carrier frequency of the power conversion means 4 can be increased. For this reason, even if the rotation speed conditions are the same, if the arithmetic processing frequency of the synchronous machine control device changes, the stability of the current feedback control changes.

  Therefore, when the processing frequency of the microcomputer that performs arithmetic processing in the synchronous machine control device changes according to the change in the arithmetic processing load, not only the rotational speed (electrical angular frequency) ω of the synchronous machine 1 but also the rotational speed of the synchronous machine 1. It is desirable to determine whether the current feedback control is valid or invalid based on the ratio of the arithmetic processing frequency of the synchronous machine controller to ω.

  In this way, when the arithmetic processing frequency of the synchronous machine control device is large, the speed at which the current feedback control is switched between valid and invalid is increased, and conversely, when the arithmetic processing frequency of the synchronous machine control device is small, the current feedback control It is possible to reduce the speed at which the control is switched between valid and invalid.

  As described above, by setting the operation condition of the synchronous machine for switching the presence or absence of the current feedback control to a condition based on the ratio of the arithmetic processing frequency of the synchronous machine control device to the rotational speed of the synchronous machine, the current feedback control becomes difficult. Current feedback control can be appropriately disabled during rotation, and current feedback control is performed according to the processing frequency of the microcomputer that performs arithmetic processing in the synchronous machine control device (which is appropriately set by the arithmetic processing load). The effect of appropriately changing the rotation speed for switching between valid and invalid can be obtained.

  The above is the description of the magnetic flux setter 8 which is a feature of the present invention.

  In the description of the first embodiment of the present invention so far, calculation in the coordinate converters 10a to 10d is not shown, and the coordinate conversion calculation will be described here.

The arithmetic expressions in the coordinate converters 10a to 10d are the expressions (34) to (37).

  However, the output currents iu, iv, and iw of the synchronous machine 1 detected by the current detecting means 7 in the coordinate conversion relating to the voltage (calculation in the expression (34) of the coordinate converter 10a and the expression (37) of 10d). Considering the control calculation delay time (dead time) until the control calculation based on the value is reflected in the three-phase voltages Vu, Vv, Vw output from the power conversion means 4, the following conversion phases ∠Φ, θ Coordinate conversion may be performed with the phase corrected by the phase correction amount θd based on the control calculation delay time.

In the first embodiment of the present invention, when the rotor position θ of the synchronous machine 1 cannot be estimated due to some trouble, the magnetic flux setting device 8 invalidates the output of the second voltage command generator 32. Alternatively, the voltage feedforward control may be performed using the well-known V / F constant control or the like. As an example, the fact that the rotor position θ of the synchronous machine 1 could not be estimated is determined from a change in the rotational speed (estimated value) ω of the synchronous machine 1 (for example, a rotational speed (estimated value that does not occur in normal operation) ) When a sudden change in ω is detected, etc.) When there is no abnormality such as the occurrence of an overcurrent in the power conversion means 4, the current feedback control is disabled and the rotational speed ω of the synchronous machine 1 immediately before the occurrence of the trouble is set. The voltage feedforward control terms vγ1, vδ1 are calculated and output by the first voltage command generator 31 of the voltage command generator 3 based on the held rotation speed.
At this time, the value of the rotor position θ of the synchronous machine 1 used for coordinate conversion or the like is obtained by integrating the held rotation speed to generate a temporary rotor position, and coordinate conversion or the like based on the temporary rotor position. Just do it.

  In this way, in the unlikely event that the rotor position θ of the synchronous machine 1 cannot be obtained due to some trouble, the current feedback control is not performed and the control without using the rotor position of the synchronous machine is further performed. Although the performance is inferior to normal, the minimum operation can be continued.

  In the first embodiment of the present invention, when the current feedback control is enabled after the current feedback control is once disabled, the PI controller 33 included in the second voltage command generator 32 is reset. May be.

This is because when the current feedback control is disabled, the value of the integral calculation term of the PI controller 33 is held, and when the current feedback control is enabled, the value of the held integral calculation term is the second voltage command generation. The voltage command output value from the voltage command generator 3 may be suddenly changed, and the second time immediately after the PI controller 33 is reset and the current feedback control is enabled for the purpose of preventing this. The output of the voltage command generator 32 is set to zero.
In this way, when the current feedback control is switched from invalid to effective, the effect of continuing operation without being affected by the switching can be obtained.

  The above is description of the synchronous machine control apparatus in Embodiment 1 of this invention.

  According to this invention, the control system which can operate the torque and magnetic flux of the synchronous machine 1 independently is comprised. Under operating conditions in which current feedback control is possible, magnetic flux feedback control is performed so as to follow a suitable magnetic flux command according to the operation purpose, and an error with the actual armature linkage flux is small and a stable value can be obtained from the estimated value. A torque command and a voltage command are generated based on the magnetic flux command value. Also, under the operating conditions where current feedback control is difficult, magnetic flux feedback control cannot be performed by the magnetizing current command generator, so the command is based on the estimated armature linkage flux close to the actual armature linkage flux. Is generated. With such a configuration, there is an effect that the controllability is good and the torque following the desired torque command can be output without providing a position detector for detecting the rotor position.

  In the first embodiment of the present invention, when the rotor position cannot be estimated, current position control is not performed, and control without using the rotor position of the synchronous machine is performed, thereby detecting the rotor position. Even if it is not possible, there is an effect that it is possible to continue driving.

  Further, in the first embodiment of the present invention, when the current feedback control is once again switched from valid to invalid, and then when the current feedback control is validated again, the PI controller of the second voltage command generator is reset. Thus, there is an effect that the current feedback control can be continued without being affected by the switching before and after switching between valid and invalid.

Embodiment 2. FIG.
FIG. 7 shows a synchronous machine control system including the synchronous machine 1 and the synchronous machine control device in Embodiment 2 of the present invention.

In the first embodiment, the embodiment in which the magnetic flux calculator 6 does not include the position detector for estimating the rotational speed ω and the rotor position θ of the synchronous machine 1 has been described. However, in the second embodiment, the magnetic flux calculator 6, the rotational speed ω and the rotor position θ of the synchronous machine 1 are not estimated, the rotor position θ of the synchronous machine 1 is detected by the position detector 11, and the speed calculator 12 is based on the detected rotor position θ. Thus, the rotational speed ω of the synchronous machine 1 is calculated.
The following description will focus on the parts (position detector 11, speed calculator 12, magnetic flux calculator 6a) that are different from the first embodiment, and the description of the same parts will be omitted as appropriate.

  The position detector 11 detects the rotor position θ of the synchronous machine 1 using a known resolver, encoder, or the like. The speed calculator 12 performs a differential operation based on the detected rotor position θ, and calculates the rotational speed (electrical angular frequency) ω of the synchronous machine 1.

  The magnetic flux calculator 6 may be configured to have the same adaptive observer 20 as in the first embodiment. However, in the second embodiment, a mechanism for estimating the rotational speed ω and the rotor position θ is not necessary. The magnetic flux calculator 6 may be configured as follows.

  FIG. 8 is an example of a configuration diagram of the magnetic flux calculator 6a in the second embodiment of the present invention. The magnetic flux calculator 6 a includes a current-type magnetic flux calculator 61 instead of the adaptive observer 20.

  In FIG. 8, the coordinate converter 10c converts the output currents iu, iv, iw of the synchronous machine 1 into the currents id, iq on the dq axis based on the rotor position θ based on the equation (36). The current-type magnetic flux calculator 61 calculates (estimates) the armature flux linkage absolute value | Φ | and (estimates) the armature flux linkage phase ∠Φ from the currents id and iq on the dq axis and outputs them.

なお、界磁（永久磁石）磁束がない同期機ではΦm＝０となる。 In the synchronous machine 1 having the field (permanent magnet) magnetic flux Φm, the relationship shown in the equation (38) is established between the current and the actual armature linkage flux. Here, the d-axis component of the actual armature linkage flux is Φd, and the q-axis component of the actual armature linkage flux is Φq.

In a synchronous machine having no field (permanent magnet) magnetic flux, Φm = 0.

  In the current-type magnetic flux calculator 61, the (estimated) electric machine is based on the above-mentioned equations (14) and (15) from the d-axis component pd 0 and the q-axis component pq 0 of the estimated armature linkage flux obtained by the equation (38). The absolute value of the interlinkage magnetic flux | Φ | and the (estimated) armature interlinkage magnetic flux phase ∠Φ are calculated and output.

It is known that the dq-axis inductances Ld and Lq used in the calculation of the equation (38) change depending on the output current of the synchronous machine 1 due to magnetic saturation, and the output current (for example, the current on the dq-axis) is previously determined. id, iq) and the dq axis inductance are stored in the form of a mathematical expression or a table, and by changing according to the output current, an error in estimating the magnetic flux due to the inductance fluctuation can be reduced. good.
In FIG. 7, a magnetic flux calculator 6b shown below may be used instead of the magnetic flux calculator 6a.

  FIG. 9 is an example of a configuration diagram of the magnetic flux calculator 6b in the second embodiment of the present invention. The magnetic flux calculator 6b has a voltage-type magnetic flux calculator 62 instead of the current-type magnetic flux calculator 61 in the magnetic flux calculator 6a.

  In FIG. 9, the coordinate converter 10d converts the three-phase voltage commands Vu *, Vv *, and Vw * into voltage commands Vd * and Vq * on the dq axis based on the rotor position θ based on the equation (37). Convert.

  The speed calculator 12 performs a differential operation based on the detected rotor position θ, and calculates the rotational speed (electrical angular frequency) ω of the synchronous machine 1.

  In the voltage type magnetic flux calculator 62, the voltage command Vd *, Vq * on the dq axis and the current id, iq on the dq axis (estimated) armature linkage magnetic flux absolute value | Φ |, (estimated) armature linkage Calculate and output the magnetic flux phase ∠Φ.

In the synchronous machine 1 having the field (permanent magnet) magnetic flux Φm, the relationship shown in the equation (39) is established between the voltage and current and the actual armature interlinkage magnetic flux.

In the equation (39), when the current change is slow, the term including the Laplace operator s may be ignored. In this case, the equation (39) is modified as the following equation (40): The When transforming from the equation (39) to the equation (40), the actual armature linkage is performed by changing the voltages Vd and Vq on the dq axis to the voltage commands Vd * and Vq * on the dq axis in accordance with the actual calculation. The d-axis component Φd and q-axis component Φq of the magnetic flux are replaced with the d-axis component pd0 and the q-axis component pq0 of the estimated armature linkage flux.

In the equation (40), when the stator winding resistance R is smaller than other terms, terms including this may be ignored. In this case, information regarding the output current of the synchronous machine 1 is not necessary.
Further, since the stator winding resistance R varies depending on the temperature of the synchronous machine 1, the temperature of the synchronous machine 1 may be detected to correct the value of the stator winding resistance R.

In the calculation of the magnetic flux calculators 6a and 6b, the output currents iu, iv and iw of the synchronous machine 1 are detected values by the current detecting means 7, and the voltage commands Vu *, Vv * and Vw * are used for the three-phase voltages. However, the current command input to the voltage command generator 3 is converted into a current command iγ *, iδ * is converted into a three-phase current (command), and the latter is detected using a known means. The detected three-phase voltage detection value may be used. Further, the calculation for obtaining (estimated) armature flux linkage absolute value | Φ | and (estimated) armature flux linkage phase ∠Φ from the voltage as in the magnetic flux calculator 6b is performed without using the rotor position θ. You may do it.
For example, the absolute value of the three-phase voltage command Vu *, Vv *, Vw *, which is obtained by subtracting the voltage drop at the stator winding resistance R due to the three-phase currents iu, iv, iw, is rotated. The value divided by the velocity (electrical angular frequency) ω is (estimated) the armature flux linkage absolute value | Φ |, 90 ° is subtracted from the phase (when ω> 0), or 90 ° is added (ω < In the case of 0), the armature flux linkage phase ∠Φ may be used, and this method makes calculation easier.

The magnetic flux calculator 6a having the current-type magnetic flux calculator 61 shown in FIG. 8 can estimate the magnetic flux regardless of the rotational speed, but uses the inductance value for the magnetic flux estimation as shown in the equation (38). It is susceptible to fluctuations in the characteristics of the synchronous machine 1 due to magnetic saturation and the like. On the other hand, the magnetic flux calculator 6b having the voltage-type magnetic flux calculator 62 shown in FIG. 9 does not use the inductance value when estimating the magnetic flux based on the equation (40). Although it is difficult to receive, when the rotation speed is low and the armature voltage is low, the estimation accuracy may be reduced.
As a method of solving these problems, the current-type magnetic flux calculator 61 and the voltage-type magnetic flux calculator 62 are used in combination, and the current-type magnetic flux calculator 61 is mainly used in a region where the rotational speed is small, and the rotational speed ω is When the voltage rises, the voltage type magnetic flux calculator 62 is mainly used so that the magnetic flux calculator is switched or the outputs of the two types of magnetic flux calculators are averaged while performing weighting with reference to the rotational speed ω. It may be used.

  In the second embodiment of the present invention, a magnetic flux calculator 6b having a voltage-type magnetic flux calculator 62 that includes a position detector that detects the rotor position θ and does not require information on the output current of the synchronous machine 1 is provided. Since it is applicable, the magnetic flux setter 8 outputs a signal for invalidating the output of the second voltage command generator 32 when the abnormality of the current detecting means 7 of the synchronous machine 1 is detected, that is, the current feedback control is invalidated. In this state, the operation may be continued without using information on the output current of the synchronous machine 1. In this way, even if an abnormality occurs in the current detection means 7 of the synchronous machine 1, it is possible to continue driving the synchronous machine 1 without using information on the output current of the synchronous machine 1.

  FIG. 10 is a configuration diagram showing a synchronous machine control system including the synchronous machine 1 and the synchronous machine control device when the current detecting means 7 is not used (cannot be used) in Embodiment 2 of the present invention.

In FIG. 10, the current detection means 7 of the synchronous machine 1 is included as a constituent element as in FIG. 1, but the part related to the current detection means 7 is omitted on the assumption that the current detection means 7 cannot be used due to an abnormality of the current detection means 7. ing.
Further, a current detection means abnormality signal indicating abnormality of the current detection means 7 is input to a magnetic flux setter 8a described later.

First, when any abnormality is detected in the current detecting means 7, the magnetic flux calculator 6b having the voltage-type magnetic flux calculator 62 is subjected to magnetic flux estimation.
When a magnetic flux calculator other than magnetic flux estimation is used for the magnetic flux calculator 6 b having the voltage type magnetic flux calculator 62, the magnetic flux calculator to be used is switched to the magnetic flux calculator 6 b having the voltage type magnetic flux calculator 62. What is necessary is just to make it a structure.
Further, a current control valid / invalid switching flag FL for invalidating the output of the second voltage command generator 32 of the voltage command generator 3 is output from the magnetic flux setter 8.

  As a configuration for realizing this, FIG. 11 shows an example of a configuration diagram of a magnetic flux setter 8 a different from the magnetic flux setter 8.

  When determining whether the current feedback control is valid or invalid, the magnetic flux setter 8a uses a current detection means in addition to the condition of the rotational speed ω of the synchronous machine 1 (or the condition related to the rotational speed ω) similar to the magnetic flux setter 8. And an operating condition determination unit 80a that uses the current detection means abnormality signal indicating abnormality 7 as a determination condition. Regardless of the rotational speed ω of the synchronous machine 1, if any abnormality is detected in the current detection means 7, the magnetic flux setter 8 a makes the current control valid / invalid switching flag FL invalidating the output of the second voltage command generator 32. Is output.

  In response to the current control valid / invalid switching flag FL for invalidating the output of the voltage command generator 32, the voltage command generator 3 outputs vγ2 = vδ2 = the output of the second voltage command generator 32 (current feedback control term). To be zero.

  Here, the current detection means abnormality signal is output from the current detection means 7 main body when some abnormality is detected in the current detection means 7, or a micro that performs arithmetic processing in the synchronous machine control device, for example. A configuration in which the computer detects that an abnormality has occurred in the current detection means 7 based on the abnormality of the calculation result related to the current in the process of the arithmetic processing, and outputs from the microcomputer is conceivable. .

  By detecting the abnormality of the current detecting means 7 in this way, the current feedback control is not performed, so that the information on the output current of the synchronous machine 1 can be obtained even if the abnormality of the current detecting means 7 is detected. The operation can be continued without using it.

  Further, the processing when the rotor position θ of the synchronous machine 1 cannot be estimated (detected in the present embodiment) and the processing when the current feedback control is enabled from the invalidity shown in the first embodiment of the present invention. Of course, this can also be applied to the second embodiment of the present invention.

  The above is description of the synchronous machine control apparatus in Embodiment 2 of this invention.

  According to the present invention, even when a position detector for detecting the rotor position is provided, a control system capable of operating torque and magnetic flux independently is configured as in the first embodiment of the present invention. Under operating conditions in which current feedback control is possible, magnetic flux feedback control is performed so as to follow a suitable magnetic flux command according to the operation purpose, and an error with the actual armature linkage flux is small and a stable value can be obtained from the estimated value. A torque command and a voltage command are generated based on the magnetic flux command value. Also, under operating conditions where it is difficult to perform current feedback control, the magnetic flux feedback control cannot be performed by the magnetizing current command generator, so the command is issued based on the estimated armature linkage flux close to the actual armature linkage flux. Generate. With such a configuration, even when a position detector for detecting the rotor position is provided, there is an effect that the controllability is good and torque that follows a desired torque command can be output.

  Further, in the second embodiment of the present invention, since the position detector for detecting the rotor position is provided, the current feedback control is not performed when the abnormality of the current detection means is detected. Even if an abnormality is detected in the current detection means, an effect is obtained in which the operation can be continued without using information on the output current of the synchronous machine.

  In addition, in each figure, the same code | symbol shows the same or equivalent part.

1 Synchronous machine,
2 Torque current command generator,
3 Voltage command generator,
4 Power conversion means,
5 Magnetic flux command generator,
6, 6a, 6b Magnetic flux calculator,
7 Current detection means,
8, 8a Magnetic flux setting device,
9 Magnetizing current command generator,
10a-d coordinate converter,
11 position detector,
12 Speed calculator,
20 Adaptive observer,
21 Synchronous machine model,
22 deviation amplifier,
23 Gain setter,
24 speed estimator,
25 integrator,
26 Armature flux linkage converter,
31 first voltage command generator;
32 second voltage command generator;
33 PI controller,
34a-c switches,
51a-g adder / subtractor,
61 Current-type magnetic flux calculator,
62 Voltage-type magnetic flux calculator,
80, 80a Operating condition determination unit.

Claims (8)

A torque current command generator that calculates a torque current command that is a torque component of the current command from the torque command and the armature linkage flux of the synchronous machine;
A first voltage command generator that generates a first voltage command from the rotational speed of the synchronous machine, the armature flux linkage, and the torque current command ; a magnetization current command that is a magnetization component of the current command; A feedback control based on a torque current command and an output current of the synchronous machine, and a second voltage command generator for generating a second voltage command; and an output of the second voltage command generator a voltage command generator for outputting a voltage command by summing the output of said results of valid or invalid is switched first voltage command generator,
Power conversion means for applying a voltage to the synchronous machine based on a voltage command which is an output of the voltage command generator;
A magnetic flux command generator for calculating a magnetic flux command based on the torque current command and the rotational speed of the synchronous machine;
A magnetic flux calculator for estimating an estimated armature linkage flux and a rotational speed of the synchronous machine based on the output current of the synchronous machine and the voltage command;
A synchronous machine control device comprising current detection means for detecting an output current of the synchronous machine,
The armature linkage magnetic flux is output by switching between the magnetic flux command output from the magnetic flux command generator and the estimated armature linkage magnetic flux output from the magnetic flux calculator according to the operating condition of the synchronous machine. And a magnetic flux setter for outputting a signal for switching between valid and invalid of the output of the second voltage command generator;
A synchronous machine control device comprising: a magnetizing current command generator that generates the magnetizing current command based on a difference between the magnetic flux command and the estimated armature flux linkage. A torque current command generator that calculates a torque current command that is a torque component of the current command from the torque command and the armature linkage flux of the synchronous machine;
A first voltage command generator that generates a first voltage command from the rotational speed of the synchronous machine, the armature flux linkage, and the torque current command ; a magnetization current command that is a magnetization component of the current command; A second voltage command generator for generating a second voltage command by performing feedback control based on the torque current command and the output current of the synchronous machine, and the output of the second voltage command generator 32; a voltage command generator for outputting a voltage command by summing the output of said results of valid or invalid is switched first voltage command generator,
Power conversion means for applying a voltage to the synchronous machine based on a voltage command which is an output of the voltage command generator;
A magnetic flux command generator for calculating a magnetic flux command based on the torque current command and the rotational speed of the synchronous machine;
A magnetic flux calculator for estimating an estimated armature linkage flux of the synchronous machine based on the output current of the synchronous machine and the voltage command;
Current detection means for detecting the output current of the synchronous machine;
A position detector for detecting a rotor position of the synchronous machine;
A synchronous machine control device comprising a speed calculator that calculates a rotational speed of the synchronous machine based on a rotor position of the synchronous machine,
The armature linkage magnetic flux is output by switching between the magnetic flux command output from the magnetic flux command generator and the estimated armature linkage magnetic flux output from the magnetic flux calculator according to the operating condition of the synchronous machine. And a magnetic flux setter for outputting a signal for switching between valid and invalid of the output of the second voltage command generator;
A synchronous machine control device comprising a magnetization current command generator that generates a magnetization current command based on a difference between the magnetic flux command and the estimated armature linkage flux.   3. The synchronous machine control device according to claim 2, wherein the magnetic flux setting device invalidates the output of the second voltage command generator when an abnormality is detected in the current detection means for detecting the output current of the synchronous machine. A synchronous machine control device that outputs a signal.   The synchronous machine control device according to any one of claims 1 to 3, wherein the operation condition of the synchronous machine is a condition based on a rotation speed of the synchronous machine. .   The synchronous machine control device according to any one of claims 1 to 3, wherein the operation condition of the synchronous machine is a condition based on a ratio of a carrier frequency of the power conversion means to a rotation speed of the synchronous machine. A synchronous machine control device characterized by being. It In a synchronous machine control apparatus according to claim 1 or claim 2, the operating conditions of the synchronous machine and is a condition based on the ratio of the arithmetic processing frequency of the synchronous machine control device against the rotating speed of the synchronous machine A synchronous machine control device.   7. The synchronous machine control device according to claim 1, wherein the magnetic flux setting device generates the second voltage command when the rotor position of the synchronous machine cannot be estimated or detected. A synchronous machine control device characterized by outputting a signal for invalidating the output of the machine. 8. The synchronous machine control device according to claim 1, wherein the second voltage command generator includes a PI controller that performs proportional integration of an input, and the second voltage command generator includes: A synchronous machine control device, wherein the PI controller is reset when the output is enabled again after the output is switched from enabled to disabled.

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