WO2019230565A1

WO2019230565A1 - Control device of rotating machine and method for controlling same

Info

Publication number: WO2019230565A1
Application number: PCT/JP2019/020517
Authority: WO
Inventors: 藤井　淳
Original assignee: 株式会社デンソー
Priority date: 2018-05-31
Filing date: 2019-05-23
Publication date: 2019-12-05
Also published as: JP2019213257A; JP7073915B2

Abstract

This control device 20 of a rotating machine 10 having a field winding 18 in a rotor 16, and having multi-phase windings 14u, 14v, 14w of three or more phases in a stator 12 is provided with: a search signal superposition unit 82 which superposes, in the multi-phase windings, search signals IdS, IqS which have constant amplitudes and in which electrical phases change in a predetermined period; a field current sensor 70 which detects a field current flowing in the field winding; and a location estimating unit 80 which, after virtually setting the location of the rotor with respect to the stator at an arbitrary angle, superposes the search signals in the multi-phase windings by using the search signal superposition unit, and estimates, by using the field current, the location of the rotor with respect to the stator.

Description

Rotating machine control device and control method

Cross-reference of related applications

This application claims priority based on the Japanese application No. 2018-104437 filed on May 31, 2018, the entire disclosure of which is incorporated herein by reference.

The present invention relates to a control device and a control method for a rotating machine.

Various types of rotating machines have been proposed that detect the rotational position of a rotor (rotor) without a sensor. For example, in Japanese Patent Application Laid-Open No. 2005-39891, when a pulse is applied to a field winding, the current flowing through the armature winding is detected, and the position of the rotor of the rotating machine is obtained by calculation using the current. Yes. There is also known a control device for a rotating machine that injects an alternating signal into the armature winding of the rotating machine and detects the magnetic pole position of the rotor by using a signal having the same frequency component as the alternating signal (for example, No. 2006-136123).

However, when applying a pulse to the field winding, there is a problem that the accuracy in obtaining the rotor position is low. Moreover, since the current used for the calculation requires an absolute value, there is a problem that the accuracy of the current sensor affects the accuracy of the rotor position. In addition, in the method of injecting the alternating signal into the armature winding of the rotating machine, noise resistance is reduced due to the control to make the voltage of the alternating signal zero, and there is concern about the accuracy of the rotor position. There was a problem.

According to one aspect of the present invention, there is provided a control device for a rotating machine having a field winding in a rotor and a multiphase winding of three or more phases in a stator. The control device includes a search signal superimposing unit that superimposes a search signal whose amplitude is constant and an electric phase changes at a constant period on the multiphase winding, and a field for detecting a field current flowing in the field winding. After temporarily setting the magnetic current sensor and the position of the rotor with respect to the stator at an arbitrary angle, the search signal is superimposed on the multiphase winding using the search signal superimposing unit, and the field current is And a position estimating unit that estimates the position of the rotor with respect to the stator. According to this aspect, since the position estimation unit estimates the position of the rotor using the field current, it is not necessary to have saliency, and the initial position of the magnetic pole can be estimated easily and with high accuracy by a simple method.

FIG. 1 is an explanatory diagram showing a schematic configuration of a rotating machine and its control device. FIG. 2 is a flowchart for estimating the rotor position, FIG. 3 is an explanatory diagram showing the search signal and its phase. FIG. 4 is an explanatory view showing the field current when the phase of the d-axis current and the d-axis current and the search signal are superimposed when there is almost no error in the position where the rotor is temporarily set. FIG. 5 is an explanatory diagram showing a current signal and a d-axis current phase when a search signal is superimposed when there is almost no error in the position where the rotor is temporarily set. FIG. 6 is an explanatory diagram showing the phase of the d-axis current and the d-axis current and the field current If when the search signal S is superimposed when there is an error in the position where the rotor is temporarily set. FIG. 7 is an explanatory diagram showing a current signal and a d-axis current phase when a search signal is superimposed when there is an error in the position where the rotor is temporarily set.

FIG. 1 is an explanatory diagram showing a schematic configuration of the rotating machine 10 and its control device 20. The rotating machine 10 includes a stator 12 and a rotor 16. The stator 12 includes three-

phase windings

14u, 14v, and 14w. The three-

phase windings

14u, 14v, 14w are star-connected. The three-

phase windings

14u, 14v, 14w may be delta-connected. The rotor 16 includes a field winding 18.

The control device 20 includes a current command generation unit 30, a three-phase winding current control unit 40, a field current control unit 60, and a position estimation unit 80. The current command generator 30 generates a d-axis current command IdC, a q-axis current command IqC, and a field current command IfC using the torque T required for the rotating machine 10. Here, for example, when the rotating machine 10 is mounted on a vehicle, the torque T required for the rotating machine 10 is calculated using the opening degree of the accelerator pedal of the vehicle and the speed of the vehicle.

The three-phase winding current control unit 40 controls the voltages Vu, Vv, and Vw applied to the three-

phase windings

14u, 14v, and 14w using the currents of the three-

phase windings

14u, 14v, and 14w of the stator 12. The three-phase winding current control unit 40 includes

adders

41 and 42,

difference calculators

43 and 44,

PI control units

46 and 48, a three-phase voltage command conversion unit 50, a driver 52, an inverter 54, A three-phase current sensor 56 and a dq axis current converter 58 are provided.

The three-phase current sensor 56 measures currents Iu, Iv, and Iw flowing through the three-

phase windings

14u, 14v, and 14w. The dq axis current converter 58 converts the currents Iu, Iv, and Iw into a d axis current Id and a q axis current Iq.

The adder 41 adds the d-axis search signal IdS to the d-axis current command IdC. The adder 42 adds the q-axis search signal IqS to the q-axis current command IqC. The difference calculator 43 calculates a difference between the d-axis current command IdC to which the d-axis search signal IdS is added and the d-axis current Id. The difference calculator 44 calculates a difference between the q-axis current command IqC to which the q-axis search signal IqS is added and the q-axis current Iq.

The PI control unit 46 calculates the d-axis voltage command VdC by PI control using the difference between the d-axis current command IdC to which the d-axis search signal IdS is added and the d-axis current Id. The PI control unit 48 calculates the q-axis voltage command VqC by PI control using the difference between the q-axis current command IqC to which the q-axis search signal IqS is added and the q-axis current Iq.

The three-phase voltage command conversion unit 50 converts the d-axis voltage command VdC and the q-axis voltage command VqC into three-phase voltage commands VuC, VvC, and VwC. The driver 52 uses the three-phase voltage commands VuC, VvC, and VwC to generate switching signals Swu, Swv, and Sww for turning on / off switching elements provided in the inverter 54. The inverter 54 turns on and off the internal switching elements by the switching signals Swu, Swv, and Sww, and generates voltages Vu, Vv, and Vw that are applied to the three-

phase windings

14u, 14v, and 14w.

The field current control unit 60 controls the voltage Vf applied to the field winding 18 using the field current If of the field winding 18 of the rotor 16. The field current control unit 60 includes a difference calculator 62, a PI control unit 64, a driver 66, an inverter 68, and a field current sensor 70.

The field current sensor 70 measures the field current If flowing in the field winding 18 of the rotor 16. The difference calculator 62 calculates the difference between the field current command IfC and the field current If. The PI control unit 64 generates a field voltage command VfC using a difference between the field current command IfC and the field current If. The driver 66 generates a switching signal Swf for the inverter 68 using the field voltage command VfC. The inverter 68 turns on / off the internal switching element by the switching signal Swf, and generates a voltage Vf applied to the field winding 18.

The position estimation unit 80 estimates the phase θ ^ of the initial position of the rotor 16 using the field current If. The position estimation unit 80 includes a search signal superimposing unit 82, a high-pass filter 84, a zero cross detection unit 86, a rotor position estimation unit 88, a compensation unit 90, and an adder 92.

The search signal superimposing unit 82 generates search signals IdS and IqS for a certain period of the rising of the rotation of the rotor 16 and sends them to the

adders

41 and 42 of the three-phase winding current control unit 40. In the present embodiment, the search signals IdS and IqS are signals whose amplitude is constant and whose electrical phase changes at a constant cycle, for example, current signals of sine waves or cosine waves. The period of the search signals IdS and IqS is, for example, 1 ms to 10 ms (100 Hz to 1 kHz), and more preferably 4 ms to 6 ms. The fixed period of the rise of the rotation of the rotor 16 is, for example, a period of 3 to 4 periods, which is the number of periods of the search signals IdS and IqS. As described above, in the present embodiment, the three-

phase windings

14u, 14v, and 14w are applied to the three-

phase windings

14u, 14v, and 14w only for a certain period of the rise of the rotation of the rotor 16, for example, the number of periods of the search signals IdS and IqS. Voltages corresponding to the search signals IdS and IqS are superimposed.

The high pass filter 84 extracts a current signal Ifac having a frequency component corresponding to the search signals IdS and IqS from the field current If measured by the field current sensor 70. The zero cross detector 86 detects the zero cross point of the current signal Ifac. The zero cross point is a point where the value of the current signal Ifac becomes zero. The rotor position estimation unit 88 estimates the initial position of the rotor 16 using the position of the zero cross point and the change in the current signal Ifac before and after the zero cross point. The compensation unit 90 compensates for a phase change caused by the frequencies of the search signals IdS and IqS, the time constant of the high-pass filter 84, and the time constant of the rotor 16. The adder 92 calculates the phase of the initial position of the rotor 16 by adding the phase change by the compensation unit 90 to the phase θ ^ of the initial position of the rotor 16 estimated by the rotor position estimation unit 88.

FIG. 2 is a flowchart for estimating the rotor position. In step S <b> 100, the rotor 16 is temporarily set to an arbitrary angle, and then the three-phase winding current control unit 40 and the field current control unit 60 start the rotation machine 10.

In step S110, the search signal superimposing unit 82 applies the search signals IdS and IqS whose amplitude is constant and electrical phase changes at a constant cycle to the voltages Vu, Vv and Vw applied to the three-

phase windings

14u, 14v and 14w. The search signals IdS and IqS are superimposed on the currents of the three-

phase windings

14u, 14v, and 14w by being generated and superimposed on the d-axis current command IdC and the q-axis current command IqC.

FIG. 3 is an explanatory diagram showing the search signal and its phase. The lower graph in FIG. 3 is a graph showing the d-axis search signal IdS and the q-axis search signal IqS, and the upper graph is a graph showing the phases of the search signal IdS and the search signal IqS. In the present embodiment, sine wave or cosine wave current signals are used as the search signals IdS and IqS, and the search signals IdS and IqS are signals whose amplitudes are constant and electrical phases change at a constant cycle.

2, the field current sensor 70 acquires the field current If.

FIG. 4 is an explanatory diagram showing the phase of the d-axis current and the d-axis current and the field current If when the search signals IdS and IqS are superimposed when there is almost no error in the position where the rotor 16 is temporarily set. The lower graph of FIG. 4 shows the d-axis current of the stator 12 and its phase. The upper graph in FIG. 4 shows the field current If. In the rotating machine 10 having the field winding 18 on the rotor 16 and the three-

phase windings

14 u, 14 v, 14 w on the stator 12, the field winding 18 of the rotor 16 interferes only with the d-axis of the stator 12. Does not interfere with the q axis. The field current If when the search signals IdS and IqS are superimposed rises while increasing or decreasing in synchronization with the d-axis search current IdS when the rotating machine 10 is started, as shown in the upper graph.

2, the position when the field current If reaches the peak values P1, P2, P3, P4, P5, and P6 in FIG. 4 and the phase at the position are acquired. Here, the peak values P1, P2, P3, P4, P5, and P6 of the field current If are the minimum value and the maximum value when the field current If increases while increasing or decreasing. Here, it is difficult to determine whether or not the field current If has reached a peak value (minimum value or maximum value) by looking at changes in the field current If before and after that. Therefore, in the present embodiment, as will be described below, the current signal Ifac is extracted using the high-pass filter 84, and the field current If has a peak value (local minimum value) using a zero cross point at which the current signal Ifac becomes zero. Alternatively, the position where the maximum value is obtained and the phase at that position are acquired.

FIG. 5 is an explanatory diagram showing the current signal Ifac and the d-axis current phase when the search signals IdS and IqS are superimposed when there is almost no error in the position where the rotor 16 is temporarily set. The upper graph in FIG. 5 shows the current signal Ifac, and the lower graph shows the d-axis current phase. The current signal Ifac is synchronized with the search signal and has a substantially sine wave shape. As can be seen from the upper graph in FIG. 5, the current signal Ifac transitions from plus to minus or minus to plus near the zero cross points Z1, Z2, and Z3 at which the current signal Ifac becomes zero. Can easily obtain the positions of the zero-cross points Z1, Z2, and Z3 from the current signal Ifac value. Note that, as shown in FIG. 5, the current signal Ifac may have an offset. The fact that the current signal Ifac has an offset means that a direct current component is added to the current signal Ifac and the current signal Ifac is shifted to the plus side or the minus side. In FIG. 5, the graph is drawn on the assumption that there is an offset in the current signal Ifac. The zero-cross detection unit 86 can easily determine the zero-cross points Z1, Z2, Z3, etc. even when the current signal Ifac has an offset.

Next, the zero-cross detection unit 86 can easily obtain the phases PhZ1 and PhZ2 when the current signal Ifac becomes the zero-cross points Z1 and Z2 using the lower graph of FIG. Here, when the current signal Ifac has a sine wave shape having an offset, the shape up to the zero cross point with respect to the peak (maximum value or minimum value) is symmetric. Therefore, the zero cross detection unit 86 can obtain the phase PhP1 of the peak P1 sandwiched between the two zero cross points Z1 and Z2 as an intermediate phase between the phase PhZ1 of the zero cross point Z1 and the phase PhZ2 of the zero cross point Z2. That is, the zero cross detection unit 86 can easily obtain the phase PhP1 of the peak P1 by calculating (PhZ1 + PhZ2) / 2. In addition, in the current signal Ifac, since the shape up to the two zero cross points sandwiching the peak around the peak is symmetrical, the offset of the current signal Ifac is sandwiched between the two zero cross points Z1 and Z2 regardless of the value. The phase PhP1 of the peak P1 does not change. For example, in FIG. 5, when the offset becomes small, the phase PhZ1 of the zero cross point Z1 becomes small, but the phase PhZ2 of the zero cross point Z2 becomes large. As a result, the value of (PhZ1 + PhZ2) / 2 does not change. . As described above, the zero-cross detection unit 86 can easily obtain the phase at which the field current If reaches a peak by using the phase of two zero-cross points sandwiching the peak, regardless of the offset value. .

2, the rotor position estimation unit 88 estimates the initial position of the rotor 16 by utilizing the fact that the peak value of the field current If occurs at either the current phase 90 degrees or 270 degrees. The rotor position estimation unit 88 determines whether the peak value of the field current If is 90 degrees or 270 degrees based on the slope of the current signal Ifac at the zero cross points Z1 and Z2. Specifically, at the zero cross point, when the slope of the current signal Ifac is negative, it is about 0 degree, when it is positive, it is about 180 degrees, and when the peak value of the current signal Ifac is a minimum value, it is about 90 degrees. By setting the maximum value to about 270 degrees, the direction of the N pole and the S pole of the rotor 16 can be specified. The rotor position estimator 88 calculates the difference between the angle of the rotor 16 temporarily set in step S100 of FIG. 2 and the phase PhP1 of 90 degrees or 270 degrees of the peak P1 calculated using the phases of the two zero cross points. It is estimated that the phase θ ^ of 16 initial positions.

In step S150, the adder 92 adds the signal from the compensator 90 to the phase of the initial position of the rotor 16 estimated by the rotor position estimator 88 to compensate for the phase delay. The phase delay can be easily calculated using the time constant of the high-pass filter 84 and the time constant of the field winding 18 of the rotor 16. The time constant of the high-pass filter 84 can be calculated using the frequencies of the search signals IdS and IqS, and the inductance and capacitance of the components that make up the high-pass filter 84. The time constant of the field winding 18 can be calculated using the frequencies of the search signals IdS and IqS and the inductance and capacitance of the field winding 18. When the phase change due to the time constant of the high-pass filter 84 and the time constant of the field winding 18 of the rotor 16 is not compensated, the compensator 90 and the adder 92 can be omitted.

In step S160, the position estimation unit 80 determines whether the activation of the rotating machine 10 is completed. The position estimation unit 80 determines that the start of the rotating machine 10 is completed when the search signals IdS and IqS are superimposed a predetermined number of times, for example, 3 to 4 times after starting the starting of the rotating machine 10. . If the activation of the rotating machine 10 is not completed, the position estimation unit 80 returns to step S110.

FIG. 6 is an explanatory diagram showing the phase of the d-axis current Id and the d-axis current and the field current If when the search signals IdS and IqS are superimposed when there is an error in the position where the rotor 16 is temporarily set. FIG. 7 is an explanatory diagram showing the current signal Ifac and the d-axis current phase when the search signals IdS and IqS are superimposed when there is an error in the position where the rotor 16 is temporarily set. Comparing FIG. 6 and FIG. 7 with FIG. 4 and FIG. 5, the d-axis current phase is shifted because there is an error in the position where the rotor 16 is temporarily set.

Even when there is an error in the position where the rotor 16 is temporarily set, as in the case where there is no error in the position where the rotor 16 is temporarily set, the zero-cross point of the current signal Ifac and the phase when the current signal Ifac reaches the peak value are obtained. be able to. Here, in FIGS. 4 and 5, the phase when the current signal Ifac has a peak value (minimum value) is about 90 degrees, but in FIGS. 6 and 7, the current signal Ifac has a peak value (minimum value). ) Is greatly shifted from about 90 degrees. The difference between 90 degrees and the phase when the current signal Ifac has a peak value (minimum value) is the phase θ ^ of the initial position of the rotor 16, that is, the phase of the position when the rotor 16 is temporarily set. That is, in the example shown in FIGS. 4 and 5, since there is almost no error in the initial position of the rotor 16, the phase of the peak value (minimum value) is about 90 degrees. On the other hand, in the example shown in FIGS. 6 and 7, since the position error of the initial position of the rotor 16 is large, the phase of the peak value (minimum value) is shifted from 90 degrees to the initial position of the rotor 16 by the position error. Thus, according to the present embodiment, the phase θ ^ of the initial position of the rotor 16 can be easily estimated regardless of whether or not the initial position of the rotor 16 has a position error.

As described above, according to the present embodiment, after temporarily setting the position of the rotor 16 with respect to the stator 12 at an arbitrary angle, the search signals IdS and IqS are supplied to the search signal superimposing unit 82 as the three-

phase windings

14u, 14v, and 14w. The position estimation unit 80 for estimating the position of the rotor 16 with respect to the stator 12 using the field current If is provided, so that it is not necessary to have saliency, and the initial stage of the rotor 16 can be easily and accurately performed with a simple method. The phase θ of the position can be estimated.

According to the present embodiment, since the search signals IdS and IqS are sine wave or cosine wave current signals, the search signals can be given in a balanced manner to the estimated d-axis and the estimated q-axis, and the rotor 16 can be accurately obtained. Can be estimated. Further, when the search signals IdS and IqS are sine wave or cosine wave current signals, generation of high-order harmonic current in the field current If can be suppressed.

The phase of the field current corresponds to the position of the rotor. According to the present embodiment, the position estimating unit 80 can easily estimate the phase θ ^ of the initial position of the rotor using the phase of the peak value of the field current.

According to the present embodiment, the position estimation unit 80 extracts the current component Ifac using the high-pass filter 84, and extracts the phase of the peak value of the current component Ifac. Since the phase of the peak value of the current component Ifac and the phase of the peak value of the field current If are the same, the phase of the peak value of the field current If can be easily obtained.

According to the present embodiment, the position estimation unit 80 sets a phase intermediate between the phases of two adjacent zero cross points where the current signal Ifc zero-crosses as a peak value phase. It is easier to obtain the phase of the zero cross point than to obtain the phase of the peak value. Even if there is an offset in the current signal, the phase of the peak value can be acquired without being affected by the offset.

・ Modification:
In the above embodiment, a sine wave or cosine wave current signal is used as the search signals IdS and IqS, but a sine wave or cosine wave voltage signal may be used. When the search signals IdS and IqS are voltage signals, an adder may be provided between the

PI control units

46 and 48 and the three-phase voltage command conversion unit 50 instead of the

adders

41 and 42. Further, a signal other than a sine wave or cosine wave, for example, a current signal or a voltage signal of a triangular wave or a rectangular wave may be used as long as the signal has a constant amplitude and an electric phase that changes at a constant cycle.

In the above embodiment, the current signal Ifac is obtained using the high-pass filter 84, and the phase of the peak value is obtained using the zero cross point of the current signal Ifac. However, the field current If is analyzed to obtain the field The peak value of the current If may be obtained.

In the above embodiment, the zero cross detection unit 86 of the position estimation unit 80 obtains the zero cross point where the current signal Ifac becomes zero, and obtains the phase of the peak value by obtaining the middle of the two zero cross points. The zero cross detector 86 may include a differentiating circuit for differentiating the current signal Ifac, and the phase of the current signal Ifac when the differential value is zero crossed may be the peak value phase. Since the peak value of the current signal Ifac is a maximum value or a minimum value, the differential value of the current signal Ifac is zero at the peak value. Therefore, the phase at which the differential value zero-crosses can be set as the peak value phase.

In the above embodiment, the position estimation unit 80 estimates the position of the rotor 16 within the period in which the field current If is started up when the rotating machine 10 is started, but the search is performed during normal operation after the starting of the rotating machine 10. The position of the rotor 16 may be estimated by superimposing the signals IdS and IqS. However, the position estimation unit 80 estimates the position of the rotor 16 if the position of the rotor 16 is estimated by superimposing the search signals IdS and IqS within the period in which the field current If is raised when the rotating machine 10 is started. Therefore, the phase θ ^ of the position of the rotor 16 can be estimated without giving a special period.

In the above-described embodiment, the search signal superimposing unit 82 inputs the search signals IdS and IqS to the

adders

41 and 42, whereby the search signals IdS and IvS are supplied to the currents Iu, Iv, and Iw flowing in the three-

phase windings

14u, 14v, and 14w. , IqS is superimposed, but by inputting the search signals IdS, IqS to the current command generator 30, the search signals IdS, IqS are applied to the currents Iu, Iv, Iw flowing in the three-

phase windings

14u, 14v, 14w. You may superimpose.

In the above embodiment, the stator 12 is described as including the three-

phase windings

14u, 14v, and 14w, but the winding may be a multi-phase winding of three or more phases. The winding may be, for example, a four-phase or five-phase winding.

The present invention is not limited to the above-described embodiment, and can be realized with various configurations without departing from the spirit of the present invention. For example, the technical features of the embodiments corresponding to the technical features in each embodiment described in the summary section of the invention are intended to solve part or all of the above-described problems, or part of the above-described effects. Or, in order to achieve the whole, it is possible to replace or combine as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate. For example, a part of the configuration realized by hardware in the above embodiment can be realized by software. Further, at least a part of the configuration realized by software can be realized by a discrete circuit configuration.

The present invention can be realized as the following forms.

According to one aspect of the present invention, a rotating machine (3) having a multi-phase winding (14u, 14v, 14w) having three or more phases on a stator (12) is provided on the rotor (16). A control device (20) of 10) is provided. The control device includes a search signal superimposing unit (82) for superimposing a search signal (IdS, IqS) having a constant amplitude and a constant electric phase on the multi-phase winding, and the field winding. A field current sensor (70) for detecting a flowing field current and a position of the rotor with respect to the stator are temporarily set at an arbitrary angle, and then the search signal is output to the multipoint using the search signal superimposing unit. A position estimation unit (80) superposed on a phase winding and estimating the position of the rotor relative to the stator using the field current. According to this aspect, since the position estimation unit estimates the position of the rotor using the field current, it is not necessary to have saliency, and the phase of the initial position of the magnetic pole is estimated easily and with high accuracy by a simple method. it can.

In the above embodiment, the search signal may be a sine wave or cosine wave current signal, or a sine wave or cosine wave voltage signal. According to this embodiment, search signals can be given to the estimated d-axis and the estimated q-axis in a well-balanced manner, and the rotor position can be estimated with high accuracy. Further, if a current signal or voltage signal is a sine wave or cosine wave, it is possible to suppress the generation of a high-order harmonic current in the field current.

In the above embodiment, the position estimation unit may estimate the position of the rotor with respect to the stator using a peak value of the field current (If). Since the phase of the field current corresponds to the position of the rotor, the position estimation unit can easily estimate the phase of the initial position of the rotor using the peak value of the field current.

In the above embodiment, the position estimation unit may further include a filter (84) for extracting a current signal (Ifac) having a frequency component corresponding to the search signal from the field current. According to this embodiment, the peak value of the field current can be easily obtained.

In the above embodiment, the position estimation unit may set the phase of the peak value to an intermediate phase between two adjacent phases at which the current signal crosses zero. According to this aspect, even if there is an offset in the current signal, the peak value phase can be obtained without being affected by the offset.

In the above embodiment, the position estimation unit may differentiate the current signal and set a phase at which the differential value is zero-crossed as a phase of the peak value. Since the peak value of the current signal is a maximum value or a minimum value, the differential value is zero at the peak value. According to this aspect, the position estimation unit can set the phase at which the differential value obtained by differentiating the current signal zero-crosses is the phase of the peak value.

In the above aspect, the position estimation unit may set the phase of the peak value to 90 degrees or 270 degrees, and may set a difference between an angle temporarily set at an arbitrary position and the phase of the peak value as an initial position of the rotor. . According to this embodiment, it is possible to determine the N pole and the S pole without taking special measures.

In the above embodiment, the position estimation unit may determine whether the temporarily set angle is 90 degrees or 270 degrees according to the slope of the current signal at the zero cross point. According to this embodiment, it is possible to determine the directions of the N pole and S pole of the rotor without taking special measures.

In the above aspect, the position estimation unit includes a compensation unit that compensates for a phase change using the frequency of the search signal, the time constant of the filter, and the time constant of the field winding of the rotor. May be. According to this aspect, the position estimation unit compensates for the phase change using the frequency of the search signal, the time constant of the filter, and the time constant of the field winding of the rotor. The phase can be estimated with high accuracy.

In the above embodiment, the position estimation unit may estimate the position of the rotor within a period in which the field current is raised at the time of starting to turn on the rotating machine. According to this aspect, the phase of the initial position of the rotor can be estimated without providing a special period for estimating the position of the rotor.

Note that the present invention can be realized in various forms, for example, in the form of a rotor position estimation method for a rotating machine, in addition to a rotating machine control device.

Claims

A control device (20) for a rotating machine (10) having a field winding (18) in a rotor (16) and a multiphase winding (14u, 14v, 14w) of three or more phases in a stator (12). There,
A search signal superimposing unit (82) for superimposing a search signal (IdS, IqS) in which the amplitude is constant and the electric phase changes at a constant period on the multiphase winding;
A field current sensor (70) for detecting a field current flowing in the field winding;
After temporarily setting the position of the rotor with respect to the stator at an arbitrary angle, the search signal is superimposed on the multiphase winding using the search signal superimposing unit, and the stator is generated using the field current. A position estimation unit (80) for estimating the position of the rotor with respect to
A control device comprising:
The control device according to claim 1,
The search device is a control device that is a sine wave or cosine wave current signal or a sine wave or cosine wave voltage signal.
The control device according to claim 2,
The said position estimation part is a control apparatus which estimates the position of the said rotor with respect to the said stator using the peak value of the said field current (If).
The control device according to claim 3,
The position estimation unit further includes a filter (84) that extracts a current signal (Ifac) having a frequency component corresponding to the search signal from the field current.
The control device according to claim 4,
The said position estimation part is a control apparatus which makes the phase of the peak value the intermediate | middle phase of two adjacent phases where the said current signal carries out zero crossing.
The control device according to claim 4,
The said position estimation part is a control apparatus which differentiates the said electric current signal, and makes the phase where a differential value zero-crosses be the phase of the said peak value.
The control device according to claim 5 or 6,
The position estimating unit sets the phase of the peak value to 90 degrees or 270 degrees, and sets a difference between an angle temporarily set at an arbitrary position and the phase of the peak value as an initial position of the rotor.
The control device according to claim 7,
The said position estimation part is a control apparatus which discriminate | determines whether the temporarily set angle is either 90 degree | times or 270 degree | times according to the inclination in the zero crossing point of the said current signal.
The control device according to claim 7 or 8, comprising:
The position estimation unit includes a compensation unit that compensates for a phase change using a frequency of the search signal, a time constant of the filter, and a time constant of the field winding of the rotor.
The control device according to any one of claims 1 to 9,
The said position estimation part is a control apparatus which estimates the position of the said rotor within the period which raises the said field current at the time of starting which turns on the said rotary machine from the on.
A control method for a rotating machine (10) having a field winding (18) in a rotor (16) and a multiphase winding (14u, 14v, 14w) having three or more phases in a stator (12),
Temporarily set the rotor position relative to the stator at an arbitrary angle,
A search signal (IdS, IqS) in which the amplitude is constant and the electrical phase changes at a constant period is superimposed on the multiphase winding,
Detecting a field current flowing in the field winding,
Estimating the position of the rotor relative to the stator using the field current;
Controlling the rotating machine,
Control method.