Control device for a three-phase alternating current rotating machine

Abstract

Provided is a control device for a three-phase AC rotary machine capable of accurately estimating CT gain imbalance. The control device for a three-phase AC rotary machine defines a predetermined detection signal in at least two phases of detected current as a reference, detects an inter-phase gain error between a reference phase and a non-reference phase based on a d-axis current and an electric angle, and reflects an operation result of the inter-phase gain error in a gain of a current detector of the non-reference phase. Thus, CT gain imbalance can be accurately estimated.

Description

Technical Field

[0001] This disclosure relates to a control device for a three-phase AC rotating machine. Background Technology

[0002] Patent document 1 discloses a control device for a three-phase AC rotary machine. This control device estimates the CT gain imbalance by extracting information equivalent to the 2f pulsation of the dq axis current when the motor is energized, and appropriately corrects the CT gain imbalance.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 6-121569 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, the control device described in Patent Document 1 uses torque command values ​​as information equivalent to the 2f pulsation of the dq-axis current when the motor is energized. In a motor control device that includes a current control system based on speed feedback control, when CT correction calculations are performed during motor drive, the overall open-loop transfer characteristics of the device sometimes attenuate the ripple frequency caused by CT gain imbalance due to the settings of the current control loop and its outer speed control loop. In this case, it is impossible to accurately estimate the CT gain imbalance.

[0008] This disclosure was made to solve the aforementioned problems. The purpose of this disclosure is to provide a control device for a three-phase AC rotary machine capable of accurately estimating CT gain imbalance.

[0009] means for solving problems

[0010] The control device for a three-phase AC rotating machine disclosed herein includes: a current detector that detects the current in at least two of the three phases of the three-phase AC rotating machine; an A / D converter that performs A / D conversion on the current detected by the current detector; a coordinate transformation unit that performs mutual conversion between three-phase coordinates and dq coordinates; and a current control unit that generates a voltage command value as a voltage control input based on the difference between a current command value, which is a control input for the current, and a current feedback value, and corrects the voltage command value based on the current command value to eliminate interference between the dq axes, wherein the current feedback value is obtained through the coordinate transformation unit. The system comprises: a power converter that generates a three-phase voltage based on the voltage command value and supplies the three-phase voltage to the three-phase AC rotating machine; a current detection gain error detection unit that defines a pre-set detection signal of at least two phases of the current detected by the current detector as a reference and detects the interphase gain error between the reference phase and the non-reference phase based on the d-axis current and electrical angle; and a current detection gain correction control calculation unit that reflects the calculation result of the interphase gain error detected by the current detection gain error detection unit into the gain of the current detector of the non-reference phase.

[0011] The control device for a three-phase AC rotating machine disclosed herein includes: a current detector that detects the current in at least two of the three phases of the three-phase AC rotating machine; an A / D converter that performs A / D conversion on the current detected by the current detector; a coordinate transformation unit that performs mutual conversion between three-phase coordinates and dq coordinates; and a current control unit that generates a voltage command value as a voltage control input based on the difference between a current command value, which is a control input for the current, and a current feedback value, and corrects the voltage command value based on the current command value to eliminate interference between the dq axes, wherein the current feedback value is obtained by the coordinate transformation unit. The current is obtained by performing a dq coordinate transformation on the current detected by the current detector; a power converter that generates a three-phase voltage based on the voltage command value and supplies the three-phase voltage to the three-phase AC rotating machine; a current detection gain error detection unit that defines a preset detection signal of at least two phases of the current detected by the current detector as a reference, and detects the interphase gain error between the reference phase and the non-reference phase based on the error signal of the d-axis current and the electrical angle; and a current detection gain correction control calculation unit that reflects the calculation result of the interphase gain error detected by the current detection gain error detection unit into the gain of the current detector of the non-reference phase.

[0012] The control device for a three-phase AC rotating machine disclosed herein includes: a current detector that detects the current in at least two of the three phases of the three-phase AC rotating machine; an A / D converter that performs A / D conversion on the current detected by the current detector; a coordinate transformation unit that performs mutual conversion between three-phase coordinates and dq coordinates; a current control unit that generates a voltage command value as a control input for voltage based on the difference between a current command value, which is a control input for the current, and a current feedback value that corrects the voltage command value based on the current command value to eliminate interference between the dq axes, wherein the current feedback value is obtained by the coordinate transformation unit performing dq coordinate conversion on the current detected by the current detector; a power converter that generates a three-phase voltage based on the voltage command value and supplies the three-phase voltage to the three-phase AC rotating machine; and a current detection gain error detection unit that defines a preset detection signal among the currents of at least two phases detected by the current detector as a reference, and detects the interphase gain error between the reference phase and the non-reference phase based on the d-axis current and electrical angle.

[0013] The effects of the invention

[0014] According to this disclosure, the interphase gain error between the reference phase and the non-reference phase is detected. Therefore, CT gain imbalance can be accurately estimated. Attached Figure Description

[0015] Figure 1 This is a block diagram of the control device for the three-phase AC rotating machine in Embodiment 1.

[0016] Figure 2 This is a block diagram of the current control unit of the control device for the three-phase AC rotating machine in Embodiment 1.

[0017] Figure 3 This is a block diagram of the three-phase current calculation unit of the control device for the three-phase AC rotating machine in Embodiment 1.

[0018] Figure 4 This is a graph showing the characteristic waveform of the relationship between the observed d-axis current and the electrical angle in the system of the control device for the three-phase AC rotating machine in Application Embodiment 1 when there is a V-phase gain error.

[0019] Figure 5 This is a graph showing the characteristic waveform of the relationship between the observed d-axis current and the electrical angle in the system of the control device for the three-phase AC rotating machine in Application Embodiment 1 when there is a W-phase gain error.

[0020] Figure 6 This is a graph showing the characteristic waveforms of the relationship between the observed d-axis current and the electrical angle in the system of the control device for the three-phase AC rotating machine in Application Embodiment 1 when there are V-phase gain errors and W-phase gain errors.

[0021] Figure 7 This is the first example of a block diagram of the current detection gain error detection unit of the control device for the three-phase AC rotating machine in Embodiment 1.

[0022] Figure 8 This is the second example of a block diagram of the current detection gain error detection unit of the control device for the three-phase AC rotating machine in Embodiment 1.

[0023] Figure 9 This is a diagram illustrating an example of the operation of the sampling and holding control signal and the polarity specification signal of the control device for the three-phase AC rotating machine in Embodiment 1 relative to the electrical angle.

[0024] Figure 10 This is a diagram illustrating an example of the operation of the sampling and holding control signal and the polarity specification signal of the control device for the three-phase AC rotating machine in Embodiment 1 relative to the electrical angle.

[0025] Figure 11 This is a block diagram of the current detection gain correction control calculation unit of the control device for the three-phase AC rotating machine in Embodiment 1.

[0026] Figure 12 This is a hardware structure diagram of the control device for the three-phase AC rotating machine in Implementation Method 1.

[0027] Figure 13 This is a block diagram of the control device for the three-phase AC rotating machine in Embodiment 2.

[0028] Figure 14 This is a graph showing the characteristic waveform of the relationship between the observed d-axis current and the electrical angle in the system of the control device for the three-phase AC rotating machine in Application Embodiment 2 when there is a W-phase gain error.

[0029] Figure 15 This is a graph showing the relationship between the observed d-axis current and the electrical angle in the control device system of the three-phase AC rotating machine in Application Embodiment 2 when there is a W-phase gain error, as well as the characteristic waveform of the detection timing of the W-phase gain error.

[0030] Figure 16 This is a graph showing the relationship between the observed d-axis current and the electrical angle in the control device system of the three-phase AC rotating machine in Application Embodiment 2 when there is a VW phase gain error, as well as the characteristic waveform of the detection range of the W phase gain error.

[0031] Figure 17 This is a block diagram of the three-phase current calculation unit of the control device for the three-phase AC rotating machine in Embodiment 2.

[0032] Figure 18This is a block diagram of the first example of the current detection gain error detection unit of the control device for the three-phase AC rotating machine in Embodiment 2.

[0033] Figure 19 This is a block diagram of the second example of the current detection gain error detection unit of the control device for the three-phase AC rotating machine in Embodiment 2.

[0034] Figure 20 This is a diagram illustrating an example of the operation of the sampling and holding control signal and the polarity specification signal of the control device for the three-phase AC rotating machine in Embodiment 1 relative to the electrical angle.

[0035] Figure 21 This is a block diagram of the current detection gain correction control calculation unit of the control device for the three-phase AC rotating machine in Embodiment 2.

[0036] Figure 22 This is a block diagram of the first example of the control device for the three-phase AC rotating machine in Embodiment 3.

[0037] Figure 23 This is a block diagram of the second example of the control device for the three-phase AC rotating machine in Embodiment 3.

[0038] Figure 24 This is a block diagram of the current control section of the control device for the three-phase AC rotating machine in Embodiment 3.

[0039] Figure 25 This is a block diagram of the current detection gain error detection unit in the first example of the control device for the three-phase AC rotating machine in Embodiment 3.

[0040] Figure 26 This is a block diagram of the current detection gain error detection unit in the second example of the control device for the three-phase AC rotating machine in Embodiment 3.

[0041] Figure 27 This is a block diagram of the current detection gain error detection unit of the control device for the three-phase AC rotating machine in Embodiment 4.

[0042] Figure 28 This is a block diagram of a portion of the current detection gain error detection unit of the control device for the three-phase AC rotating machine in Embodiment 4.

[0043] Figure 29 This is a flowchart illustrating the adjustment algorithm executed by the control device of the three-phase AC rotating machine in Embodiments 1 to 3.

[0044] Figure 30 This is a flowchart illustrating the adjustment algorithm executed by the control device of the three-phase AC rotating machine in Embodiments 1 to 3.

[0045] Figure 31 This is a block diagram of the main parts of the control device for the three-phase AC rotating machine in Embodiment 5. Detailed Implementation

[0046] The embodiments will be described with reference to the accompanying drawings. Furthermore, in each drawing, the same or equivalent parts are labeled with the same reference numerals. Repetitive descriptions of these parts have been simplified or omitted where appropriate.

[0047] Implementation method 1.

[0048] Figure 1 This is a block diagram of the control device for the three-phase AC rotating machine in Embodiment 1. Figure 2 This is a block diagram of the current control unit of the control device for the three-phase AC rotating machine in Embodiment 1. Figure 3 This is a block diagram of the three-phase current calculation unit of the control device for the three-phase AC rotating machine in Embodiment 1.

[0049] like Figure 1 As shown, the control device 20 of the motor 1 includes a current control unit 2, a dq-three-phase conversion unit 3, a three-phase-dq conversion unit 4, a power converter 5, current detectors 6a, 6b, and 6c, an A / D converter 7a, 7b, and 7c, a rotational position detector 8, a differential calculation unit 9, a three-phase current calculation unit 10, a current detection gain error detection unit 11, and a current detection gain correction control calculation unit 12.

[0050] like Figure 2 As shown, the current control unit 2 includes a d-axis current control unit 21, a q-axis current control unit 22, and a non-interference control unit 23.

[0051] Normally, the control device 20 controls the motor 1 via the current control unit 2, the dq-three-phase conversion unit 3, the three-phase-dq conversion unit 4, the power converter 5, the current detectors 6a, 6b, and 6c, the A / D converters 7a, 7b, and 7c, the rotational position detector 8, the differential calculation unit 9, and the three-phase current calculation unit 10. At this time, the motor 1 rotates, causing the d-axis current command value id to be generated. * and q-axis current command value iq * .

[0052] At this time, the rotary position detector 8 detects the rotor position (electric angle) θre of the motor 1. The differential calculation unit 9 outputs the electrical angular velocity ωre by performing time differentiation on θre. Current detectors 6a, 6b, and 6c detect the three-phase currents flowing to the motor 1, namely the U-phase current iu, the V-phase current iv, and the W-phase current iw. A / D converters 7a, 7b, and 7c convert the U-phase current iu, the V-phase current iv, and the W-phase current iw into current detection values ​​ius, ivs, and iws, respectively.

[0053] like Figure 3 As shown, the three-phase current calculation unit 10 uses the current detection value ius as a reference signal and outputs it directly without any operation. The three-phase current calculation unit 10 multiplies the current detection values ​​ivs and iws by the gain imbalance correction values ​​cor_ivs and cor_iws, respectively, and outputs the gain-corrected current detection values ​​i'v and i'w.

[0054] The three-phase-dq conversion unit 4 performs a three-phase-dq conversion on the control coordinate (dq) axis based on θre after gain correction of the three-phase current detection values ​​ius, i'v, and i'w. The current control unit 2 accepts the input of the converted d-axis current observation value id and the q-axis current observation value iq. The current control unit 2 also accepts the input of the electric angular velocity ωre, the d-axis current command value id*, and the q-axis current command value iq*. In the current control unit 2, the d-axis current control unit 21 generates the d-axis voltage command value vd** for controlling the desired d-axis current value based on the difference between id* and id, i.e., id_er. The q-axis current control unit 22 generates the q-axis voltage command value vq** for controlling the desired q-axis current value based on the difference between iq* and iq, i.e., iq_er. Furthermore, both the d-axis current control unit 21 and the q-axis current control unit 22 are so-called PI control compensator structures, resulting in the property that the steady-state deviation converges to zero.

[0055] The non-interference control unit 23 calculates the voltage components that interfere with each other between the d and q axes based on id* and iq*. The non-interference control unit 23 corrects the voltage command value vd** for the d-axis and the voltage command value vq** for the q-axis according to the calculation results, thereby reducing the control error caused by mutual interference. The correction calculation result for the d-axis is vd*. The correction calculation result for the q-axis is vq*.

[0056] The dq-three-phase conversion unit 3 performs dq-three-phase conversion on the dq axis based on θre, using vd* and vq* output from the current control unit 2 as input. The power converter 5 receives the converted value from the dq-three-phase conversion unit 3 as a three-phase AC voltage command signal. The power converter 5 controls the motor 1, which is a three-phase AC rotating machine, through its AC output, thereby generating the desired dq axis current.

[0057] Next, CT correction will be explained without using diagrams.

[0058] In the CT gain imbalance of each phase, the CT gain of phase U becomes the benchmark. Phase V becomes (1-α) times that of phase U. Phase W becomes (1-β) times that of phase U. At this time, the following equations (1) and (2) hold.

[0059] [Formula 1]

[0060] A v =(1-α)A u

[0061] [Formula 2]

[0062] A w =(1-β)A u

[0063] Based on equations (1) and (2), the d-axis current observation value id is represented by the following equation (3), which will be used as the reference U-phase current amplitude Au, the error α between the V phase and the U phase as the reference phase, and the error β between the W phase and the U phase as the reference phase.

[0064] [Formula 3]

[0065]

[0066] The first term on the left-hand side of equation (3) uses the error α as the amplitude parameter. This sine wave is synchronized with twice the period of the V-phase current, which is delayed by 2π / 3 relative to the U-phase current. The second term on the left-hand side of equation (3) uses the error β as the amplitude parameter. This sine wave is synchronized with twice the period of the W-phase current, which is advanced by 2π / 3 relative to the U-phase current.

[0067] According to equation (3), the d-axis current observation value id is always zero when there is no CT gain imbalance and the errors α and β are zero. When the error α is not zero, the d-axis current observation value id becomes the sum of sine waves with a frequency twice that of the U-phase current and a phase synchronized with the V-phase current. When the error β is not zero, the d-axis current observation value id becomes the sum of sine waves with a frequency twice that of the U-phase current and a phase synchronized with the W-phase current. These sine waves have the same frequency. The amplitude of these sine waves is proportional to the amount of error. These sine waves become waveforms with different phases.

[0068] The following describes a method for independently detecting errors α and β by utilizing the property that a sine wave periodically becomes zero.

[0069] When only the error α is detected based on the waveform of the d-axis current observation value id, it is independent of the value of error β, so the value of error β can be made invalid. Specifically, sampling and holding can be performed when the sine function of the second term on the right side of equation (3) becomes zero. The specific timing is expressed by the following equation (4).

[0070] [Formula 4]

[0071]

[0072] In equation (4), N is an integer.

[0073] When the d-axis current observation value id is sampled and held according to the timing in equation (4), the error is detected with positive polarity for the error α when N is even. When N is odd, the error is detected with negative polarity for the error α.

[0074] When only the error β is detected based on the waveform of the d-axis current observation value id, it is independent of the value of error α, and the value of error α can be made invalid. Specifically, sampling and holding can be performed when the sine function of the first term on the right side of equation (3) becomes zero. The specific timing is expressed by the following equation (5).

[0075] [Formula 5]

[0076]

[0077] In equation (5), N is an integer.

[0078] When the d-axis current observation value id is sampled and held according to the timing in equation (5), the error is detected with negative polarity for the error β when N is even. When N is odd, the error is detected with positive polarity for the error β.

[0079] To help understand the above, use Figures 4 to 6, and then provide a detailed explanation of the waveform.

[0080] Figure 4 This is a graph showing the characteristic waveform of the relationship between the observed d-axis current and the electrical angle in the system of the control device for the three-phase AC rotating machine in Application Embodiment 1 when there is a V-phase gain error. Figure 5 This is a graph showing the characteristic waveform of the relationship between the observed d-axis current and the electrical angle in the system of the control device for the three-phase AC rotating machine in Application Embodiment 1 when there is a W-phase gain error. Figure 6 This is a graph showing the characteristic waveform of the relationship between the observed d-axis current and the electrical angle in the control device system of the three-phase AC rotating machine in Application Embodiment 1 when there are V-phase gain errors and W-phase gain errors.

[0081] Figure 4 The electrical angle waveform of the d-axis current observation value id is shown based on equation (3), where the error α is set to a non-zero value Δ and the error β is set to zero. The electrical angle θre, which serves as the horizontal axis, is defined by the angle of one cycle of the U-axis current. Figure 4 The solid line waveform represents the waveform of the d-axis current observation value id when α = Δ. Figure 4 In the solid waveform, the frequency is twice the frequency of the U-phase current. Figure 4 In the solid waveform, the phase is delayed by 2 / 3π relative to the frequency of the U-phase current. Figure 4 The dashed waveform represents the waveform when the error α is set to twice Δ. Figure 4 In the dashed waveform, the period and phase are related to... Figure 4 The period and phase of the solid line waveform are the same. Figure 4 In the dashed waveform, the amplitude becomes Figure 4 The amplitude is twice that of the solid line waveform. Therefore, the amplitude information becomes the magnitude of the error α.

[0082] Figure 5 The electrical angle waveform of the d-axis current observation id is shown when the error β is set to a non-zero value Δ based on equation (3) and when the error β is set to zero. The electrical angle θre, which is the horizontal axis, is defined by the angle of one cycle of the U-axis current. Figure 5 The solid line waveform is the waveform of the d-axis current observation value id when β = Δ. Figure 5 In the solid line waveform, the frequency is twice the frequency of the U-phase current. Figure 4 In the solid waveform, the phase is 2 / 3π ahead of the frequency of the U-phase current. Figure 5 The dashed waveform represents the waveform when the error β is set to twice Δ. Figure 5 In the dashed waveform, the period and phase are related to... Figure 5 The period and phase of the solid line waveform are the same. Figure 5 In the dashed waveform, the amplitude becomes Figure 5 The amplitude is twice that of the solid line waveform. Therefore, the amplitude information becomes the magnitude of the error β.

[0083] Figure 6 The electric angle waveform of the d-axis current observation id is shown when the error α and error β are set to non-zero Δ based on equation (3). Figure 6 The single-dot dashed line is based on the waveform component of the error α and is the first component on the right side of equation (3). Figure 6 The dashed line is based on the waveform component of error β and is the second component on the right side of equation (3). Figure 6 The solid line represents the d-axis current observation value id in equation (3).

[0084] exist Figure 6 In the diagram, the white arrows indicate the timing of equation (4). The downward white arrows are for when N is even. The upward white arrows are for when N is odd. At this timing, the d-axis current observation id becomes the same value as the waveform component based on the error α. In this case, the d-axis current observation id is not affected by the error β.

[0085] exist Figure 6 In the diagram, the black arrow indicates the timing of equation (5). Figure 6 In the diagram, the downward black arrow represents the case when N is odd, and the upward black arrow represents the case when N is even. At this timing, the d-axis current observation id becomes the same value as the waveform component based on error β. In this case, the d-axis current observation id is unaffected by error α.

[0086] Next, use Figure 7 and Figure 8 To explain the implementation based on Figures 4 to 6 The block containing the description.

[0087] Figure 7 This is the first example of a block diagram of the current detection gain error detection unit of the control device for the three-phase AC rotating machine in Embodiment 1. Figure 8 This is the second example of a block diagram of the current detection gain error detection unit of the control device for the three-phase AC rotating machine in Embodiment 1.

[0088] like Figure 7 As shown, the current detection gain error detection unit 11 receives the electrical angle θre and the d-axis current observation value id as inputs. The current detection gain error detection unit 11 outputs the V-phase gain error Er_ivs and the W-phase gain error Er_iws.

[0089] In the current detection gain error detection unit 11, the phase determination unit 111 determines the timing at which the electrical angle θre reaches a preset value. At this timing, the phase determination unit 111 outputs a sample-and-hold control signal t_v and a sample-and-hold control signal t_w.

[0090] The sample-and-hold control signal t_v is output at a timing when N in equation (4) with respect to the electrical angle θre is an even number. The sample-and-hold control signal t_w is output at a timing when N in equation (4) with respect to the electrical angle θre is an odd number.

[0091] The first sample-and-hold unit 112 samples and holds the d-axis current observation value id at a timing when the sample-and-hold control signal t_v is input. Therefore, the first sample-and-hold unit 112 generates a positive V-phase gain error Er_ivs with a multiplier relative to the error α and outputs it.

[0092] The second sample-and-hold unit 113 samples and holds the d-axis current observation value id at a timing when the sample-and-hold control signal t_w is input. Therefore, the second sample-and-hold unit 113 generates a positive W-phase gain error Er_iws with a multiplier relative to the error β preset and then outputs it.

[0093] The current detection gain error detection unit 11 can perform a maximum of 4 samples of error α and error β within one cycle of the electrical angle, based on the U-phase electrical angle and synchronized with twice the frequency.

[0094] exist Figure 7 In the example, to simplify the processing, two of the four positive polarity timings were selected.

[0095] Conversely, when motor 1 operates at extremely low speeds, the detection sampling period of the current detection gain error signal is sometimes shortened. In this case, such as Figure 8 In the example, the maximum number of samples within one cycle of the electric angle can be set to 4.

[0096] exist Figure 8 In this circuit, the current detection gain error detection unit 11 receives the electrical angle θre and the d-axis current observation value id as inputs. The current detection gain error detection unit 11 outputs the V-phase gain error Er_ivs, the W-phase gain error Er_iws, the polarity specification signal p / n1, and the polarity specification signal p / n2.

[0097] The polarity specification signal p / n1 is a signal that switches to H or L when N in equation (4) becomes an integer. For example, the polarity specification signal p / n1 becomes H when N is even. For example, the polarity specification signal p / n1 becomes L when N is odd.

[0098] The polarity specification signal p / n2 is a signal that switches to H or L when N in equation (5) becomes an integer. For example, the polarity specification signal p / n1 becomes H when N is even. For example, the polarity specification signal p / n1 becomes L when N is odd.

[0099] The first sample-and-hold unit 112 samples and holds the d-axis current observation value id at a timing when N in equation (4) becomes an integer. During this time, while the gain error signal is of opposite polarity, the polarity reversal unit 115 outputs the polarity-reversed signal. In this case, the switching unit 116 selects the polarity-reversed signal. As a result, the detection polarity of the V-phase gain error Er_ivs becomes positive.

[0100] The second sample-and-hold unit 113 samples and holds the d-axis current observation value id at a timing when N in equation (5) becomes an integer. During this time, while the gain error signal is of opposite polarity, the polarity reversal unit 117 outputs the polarity-reversed signal. In this case, the switching unit 118 selects the polarity-reversed signal. As a result, the detection polarity of the V-phase gain error Er_iws becomes positive.

[0101] Next, use Figure 9 This shows an example of the action of the sample-and-hold control signal t_v and the polarity specification signal p / n1 relative to the electrical angle.

[0102] Figure 9 This is a diagram illustrating an example of the operation of the sampling and holding control signal and the polarity specification signal of the control device for the three-phase AC rotating machine in Embodiment 1 relative to the electrical angle.

[0103] exist Figure 9 In this context, the sample-and-hold control signal t_v is a signal that rises from 0 to 1 when N in equation (4) with respect to the electrical angle θre is an integer. The sample-and-hold control signal t_v is supplied to the first sample-and-hold unit 112 on the rising edge.

[0104] Next, use Figure 10 This shows an example of the action of the sample-and-hold control signal t_w and the polarity specification signal p / n2 relative to the electrical angle.

[0105] Figure 10 This is a diagram illustrating an example of the operation of the sampling and holding control signal and the polarity specification signal of the control device for the three-phase AC rotating machine in Embodiment 1 relative to the electrical angle.

[0106] exist Figure 10 In this context, the sample-and-hold control signal t_w is a signal that rises from 0 to 1 when N in equation (5) with respect to the electrical angle θre is an integer. The sample-and-hold control signal t_w is supplied to the second sample-and-hold unit 113 on the rising edge.

[0107] Next, use Figure 11 The current detection gain correction control calculation unit 12 will be explained.

[0108] Figure 11This is a block diagram of the current detection gain correction control calculation unit of the control device for the three-phase AC rotating machine in Embodiment 1.

[0109] exist Figure 11 In the process, after receiving the output of the current detection gain error detection unit 11, i.e., the input of the V-phase gain error Er_ivs, the first amplifier 121 outputs the V-phase gain error Er_ivs at a preset multiplier.

[0110] Switch 125 selects whether the V-phase gain correction control is ON or OFF. The control signal for switch 125 is CT_gain_tune. When switch 125 is ON, it outputs the signal after selecting the first amplifier 121. When switch 125 is OFF, it outputs the signal after selecting 0.

[0111] The first integrator 122 is input to the output of the first amplifier 121 and integrated at a preset sampling rate. The first initial value is 1 during initial adjustment. Outside of the initial adjustment, the first initial value is set to the convergence value of the first integrator 122 during the last operation. The output of the first integrator 122 is the gain imbalance correction value cor_ivs for phase V.

[0112] After receiving the input of the W-phase gain error Er_iws from the current detection gain error detection unit 11, the second amplifier 123 outputs the W-phase gain error Er_ivs at a preset multiplier.

[0113] Switch 126 selects whether the W-phase gain correction control is ON or OFF. The control signal for switch 126 is CT_gain_tune. When switch 126 is ON, it outputs the signal after selecting the signal from amplifier 123. When switch 126 is OFF, it selects 0 and outputs it.

[0114] The second integrator 124 is input to the output of the second amplifier 123 and integrated at a preset sampling rate. The second initial value is 1 during initial adjustment. When the second initial value is not in the initial adjustment range, it is set to the convergence value of the second integrator 124 during the last operation. The output of the second integrator 124 is the gain imbalance correction value cor_iws for phase W.

[0115] Furthermore, from the viewpoint of accelerating integrator convergence, the first initial value and the second setting value assume that the convergence values ​​from the previous run and the current run are negligible. In this case, the first initial value and the second setting value are set to the convergence values ​​of the integrator. At the initial setting, there are no convergence values ​​from the previous run. Therefore, the first initial value and the second setting value are set to values ​​assuming no error, i.e., 1.

[0116] The gain imbalance correction values ​​cor_ivs for phase V and cor_iws for phase W are input to the three-phase current calculation unit 10. As a result, the gain-corrected current detection values ​​i'v and i'w are obtained. Thus, the three-phase current calculation unit 10, the three-phase-dq conversion unit 4, the current detection gain error detection unit 11, and the current detection gain correction control calculation unit 12 form a feedback control loop that functions in such a way that the gain errors er_ivs and er_iws detected by the current detection gain error detection unit 11 become zero.

[0117] exist Figure 11 In the diagram, the three-phase current calculation unit 10 (not shown) independently and simultaneously eliminates the influence of CT imbalance in each phase, obtaining current detection values ​​ius, i'v, and i'w that have been corrected for CT gain imbalance. As a result, current ripple and torque ripple caused by CT gain imbalance are eliminated.

[0118] According to Embodiment 1 described above, the current detection gain error detection unit 11 does not have a dedicated mode and detects the current detection gain error during the normal rotation of the motor 1. Therefore, it is possible to accurately estimate and correct CT gain imbalance without being affected by the open-loop transfer characteristics of the control system, without changing the wiring of the device, and without requiring a special mode for error measurement.

[0119] However, the control device 20 observes the amplitude of the oscillation of the d-axis current observation value id at a preset time. Therefore, the DC value in the waveform of the d-axis current observation value id needs to be zero. Thus, the period during which specific applications can be performed is limited to when the d-axis current command value id is... * The period is set to zero.

[0120] As a condition for the preferred functionality of this embodiment, the U-phase amplitude Au, which is the amplitude ratio parameter on the right side of equation (3), is relatively large. A larger U-phase amplitude Au results in better S / N current detection gain error detection and a higher detection ratio. To ensure this condition is met, the current command iq on the q-axis... * The current detection gain error detection unit 11 functions when the absolute value of the current is greater than a preset value. Conversely, when the q-axis current command iq... * When the absolute value of the current sensing gain becomes close to zero, the U-phase amplitude Au becomes close to zero. As a result, the S / N ratio of the current sensing gain error detection deteriorates, and the detection gain also becomes close to zero. In this case, the current sensing gain correction control can be turned off.

[0121] Furthermore, in this embodiment, the compensator of the control loop is the integrator 122, 124 of the current detection gain correction control arithmetic unit 12. This compensator of the control loop becomes a so-called Type 1 control system. In this case, the compensator of this control loop becomes a system that converges the steady-state deviation to zero.

[0122] In reality, the steady-state deviation will not be zero due to the detection noise of the current detection gain error detection unit 11. Typically, the DC value of the noise is approximately zero. Therefore, if the noise is high-frequency noise from other systems, the effect of the noise can be mitigated by setting the crossover frequency of this feedback control loop lower relative to that noise. As a result, the steady-state deviation caused by the noise can be reduced.

[0123] Furthermore, the control loop can be turned ON / OFF via switches 125 and 126, and when OFF, it maintains the values ​​of the two integrators 122 and 124 at the timing immediately preceding the OFF turn. Therefore, the control loop can operate seamlessly and stably. For example, if the switch is turned OFF when convergence of the feedback control loop is confirmed in a separate unit, or when the speed of motor 1 is less than a preset value, the opening and closing of the control loop can be easily managed.

[0124] Furthermore, when the error correction loop is type 1 and fixed follow control is performed, even if the detection gain of the current detection gain error detection unit 11 changes, the output of the current detection gain correction control calculation unit 12 remains unchanged and becomes the correct value simply by changing the open-loop gain of the error correction loop.

[0125] Next, use Figure 12 An example of control device 20 will be explained.

[0126] Figure 12 This is a hardware structure diagram of the control device for the three-phase AC rotating machine in Implementation Method 1.

[0127] The functions of the control device 20 can be implemented by a processing circuit. For example, the processing circuit has at least one processor 100a and at least one memory 100b. For example, the processing circuit has at least one dedicated hardware 200.

[0128] When the processing circuit has at least one processor 100a and at least one memory 100b, the functions of the control device 20 are implemented by software, firmware, or a combination of software and firmware. At least one of the software and firmware is described in the form of a program. At least one of the software and firmware is stored in at least one memory 100b. The at least one processor 100a implements the functions of the control device 20 by reading and executing the program stored in the at least one memory 100b. The at least one processor 100a is also referred to as a central processing unit, processing device, arithmetic unit, microprocessor, microcomputer, or DSP. For example, the at least one memory 100b is a non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, EEPROM, a disk, floppy disk, optical disk, high-density disk, mini-disk, DVD, etc.

[0129] When the processing circuit has at least one dedicated hardware 200, the processing circuit is implemented, for example, by a single circuit, a composite circuit, a programmable processor, a parallel programmable processor, an ASIC, an FPGA, or a combination thereof. For example, each function of the control device 20 is implemented by the processing circuit. For example, each function of the control device 20 is implemented by the processing circuit.

[0130] Regarding the various functions of the control device 20, some can be implemented by dedicated hardware 200, while others can be implemented by software or firmware. For example, the functions of the current detection gain correction control arithmetic unit 12 can be implemented by a processing circuit that is a dedicated hardware 200, and functions other than those of the current detection gain correction control arithmetic unit 12 can be implemented by at least one processor 100a reading and executing a program stored in at least one memory 100b.

[0131] Thus, the processing circuit implements the functions of the control device 20 through hardware 200, software, firmware, or a combination thereof.

[0132] Implementation method 2.

[0133] Figure 13 This is a block diagram of the control device for the three-phase AC rotating machine in Embodiment 2. Furthermore, parts that are the same as or equivalent to those in Embodiment 1 are labeled with the same reference numerals. Descriptions of these parts are omitted.

[0134] exist Figure 13 In the diagram, the block numbers of parts that differ from those in Embodiment 1 are marked with "a" at the end. Specifically, the parts that differ from those in Embodiment 1 are the three-phase current calculation unit 10a, the current detection gain error detection unit 11a, and the current detection gain correction control calculation unit 12a.

[0135] In embodiment 2, the control device 20 recovers the current detection value of the remaining phase based on the current detection values ​​of two of the three-phase currents iu, iv, and iw. For example, the control device 20 recovers the current detection value of phase U based on the current values ​​of phase V and phase W.

[0136] At this time, the three-phase current detection values ​​ius, ivs, and iws are expressed by equations (6) to (8).

[0137] [Formula 6]

[0138] i us =-i vs -i ws

[0139] [Formula 7]

[0140]

[0141] [Formula 8]

[0142]

[0143] Here, Av is the amplitude of the detected V-phase current. Aw is the amplitude of the detected W-phase current. θre is the electrical angle. It is the phase angle of the energized phase. Ov is for detecting the V phase offset. Ow is for detecting the W phase offset.

[0144] The control loop performs a three-phase-dq transformation on the control coordinate (dq) axis according to the electrical angle θre, and detects the observed currents id and iq to ensure they follow the current command values ​​id* and iq. * At this point, non-interference control is implemented in a way that does not interfere with id and iq. In this case, the observed d-axis current id is represented by the following equation (9).

[0145] [Formula 9]

[0146]

[0147] Here, we consider using the d-axis current command value id. * The setting is zero. In this case, the energized phase angle... The values ​​become zero. In addition, the offset of each phase detection signal is also adjusted to zero beforehand. In this case, the three-phase current detection values ​​ivs and iws are represented by the following equations (10) and (11).

[0148] [Formula 10]

[0149]

[0150] [Formula 11]

[0151]

[0152] Based on equations (10) and (11), equation (12) is obtained.

[0153] [Formula 12]

[0154]

[0155] Half of the right side of equation (12) becomes the DC offset. The d-axis current command value id... * In feedback control set to zero, DC offset is canceled. As a result, the following equation (13) is obtained.

[0156] [Formula 13]

[0157]

[0158] In equation (13), the d-axis current id is defined by the frequency of the second-order component of the electrical angle of motor 1, i.e., the 2f component. Here, in the absence of CT gain imbalance, the following equation (14) holds.

[0159] [Formula 14]

[0160] A v =A w

[0161] In this case, the d-axis current id is always zero. Conversely, when there is a CT gain imbalance, the right side of equation (13) is not zero, and the cosine function is valid. Therefore, a 2f component pulsation is generated. This 2f current pulsation becomes the torque pulsation of motor 1.

[0162] Next, the CT gain error detection method will be explained without using figures.

[0163] In the CT gain imbalance of each phase, the CT gain of phase V is the reference. Phase W is (1-β) times that of phase V. At this time, the following equation (15) holds.

[0164] [Formula 15]

[0165] A w =(1-β)A v

[0166] Based on equations (13) and (15), the d-axis current observation value id is represented by the following equation (16), which will serve as the reference V-phase current amplitude Av and the error β between the W-phase and the reference V-phase as parameters.

[0167] [Formula 16]

[0168]

[0169] The cosine wave on the left side of equation (16) uses the error β as a parameter of amplitude. This cosine wave is synchronized with twice the period of the V-phase current.

[0170] According to equation (16), the d-axis current observation value id is always zero when there is no CT gain imbalance and the error β is zero. When the error β is not zero, the d-axis current observation value id becomes the sum of a cosine wave with a frequency twice that of the U, V, and W phase currents and a phase synchronized with the U, V, and W phase currents. The amplitude of this cosine wave is proportional to the amount of error. This cosine wave becomes a waveform synchronized with the electrical angular phase of the U, V, and W phase currents.

[0171] The error β appears as a periodic function in the d-axis current observation value id. This error β is synchronized with the electrical angle phase of each phase current waveform. In this case, sampling and holding can be performed when the amplitude of equation (16) is at its maximum. The specific timing is expressed by the following equation (17).

[0172] [Formula 17]

[0173]

[0174] In equation (17), N is an integer.

[0175] When the d-axis current observation value id is sampled and held according to the timing in equation (17), the error is detected with positive polarity for the error β when N is even. When N is odd, the error is detected with negative polarity for the error β.

[0176] To help understand the above, use Figures 14 to 16 , and then provide a detailed explanation of the waveform.

[0177] Figure 14 This is a graph showing the characteristic waveform of the relationship between the observed d-axis current and the electrical angle in the system of the control device for the three-phase AC rotating machine in Application Embodiment 2 when there is a W-phase gain error. Figure 15 This is a graph showing the relationship between the observed d-axis current and the electrical angle in the control device system of the three-phase AC rotating machine in Application Embodiment 2 when there is a W-phase gain error, as well as the characteristic waveform of the detection timing of the W-phase gain error. Figure 16 This is a graph showing the relationship between the observed d-axis current and the electrical angle in the control device system of the three-phase AC rotating machine in Application Embodiment 2 when there is a VW phase gain error, as well as the characteristic waveform of the detection range of the W phase gain error.

[0178] Figure 14The electrical angle waveform of the d-axis current observation id is shown when the error β is set to a non-zero value Δ based on equation (16). The electrical angle θre, which is the horizontal axis, is defined by the angle of one cycle of the V-axis current as defined by equation (10). Figure 14 The solid line waveform is the id waveform of the d-axis current observation when β = Δ. Figure 14 In the solid waveform, the frequency is twice the frequency of the U-phase current. Figure 14 In the solid line waveform, the phase is synchronized with the cosine wave waveform of the sine wave, which is twice the frequency of the U-phase current. Figure 14 The dashed waveform represents the waveform when the error β is set to twice Δ. Figure 14 In the dashed waveform, the period and phase are related to... Figure 14 The period and phase of the solid line waveform are the same. Figure 14 In the dashed waveform, the amplitude becomes Figure 14 The amplitude is twice that of the solid line waveform. Therefore, the amplitude information becomes the magnitude of the error β.

[0179] Figure 15 The electrical angle waveform of the d-axis current observation id is shown when the error β is set to a non-zero value Δ based on equation (16). The electrical angle θre, which is the horizontal axis, is defined by the angle of one cycle of the V-axis current as defined by equation (10). The arrows indicate the timing of equation (17). The downward arrow is the arrow when N is even. The upward arrow is the arrow when N is odd. The downward arrow indicates the timing of the maximum value of the vibration amplitude of the d-axis current observation id relative to the error β. The upward arrow indicates the timing of the minimum value of the vibration amplitude of the d-axis current observation id relative to the error β. When the error β is detected with positive polarity, sampling and holding can be performed at the timing when N is even. When the sampling period is shorter, the information when N is odd can be reversed and used.

[0180] Figure 16 An example of synchronous detection without sampling is shown. Figure 16 In the dashed line, the range where the d-axis current observation id becomes a negative electrical angle θre corresponds to the period of polarity reversal of the error information. Figure 16 In the diagram, this range is indicated by a white arrow. Within this range, error information with reversed polarity is used. The reversed d-axis current observation value id is determined by... Figure 16 The solid line represents this. The result is a detection waveform with the same error information as the range of the electrical angle θre where the d-axis current observation id is positive (i.e., the range indicated by the black arrow). In this example, the stability of the feedback loop correcting the error caused by the phase spread (phase period) due to sampling is ensured even with a longer sampling period at extremely low rotation speeds.

[0181] Next, the CT correction method will be explained.

[0182] Figure 17 This is a block diagram of the three-phase current calculation unit of the control device for the three-phase AC rotating machine in Embodiment 2. Figure 18 This is a block diagram of the first example of the current detection gain error detection unit of the control device for the three-phase AC rotating machine in Embodiment 2. Figure 19 This is a block diagram of the second example of the current detection gain error detection unit of the control device for the three-phase AC rotating machine in Embodiment 2.

[0183] like Figure 17 As shown, the three-phase current calculation unit 10a uses the current detection value ius as a reference signal and outputs it directly without any operation. The three-phase current calculation unit 10a multiplies the current detection value iws by the gain imbalance correction value cor_iws and outputs the gain-corrected current detection value i'v. The three-phase current calculation unit 10a outputs the value calculated by the following equation (18) as the U-phase current detection value i'u.

[0184] [Formula 18]

[0185] i′ u =-(i vs +i′ w )

[0186] like Figure 18 As shown, the current detection gain error detection unit 11a receives the electrical angle θre and the d-axis current observation value id as inputs. The current detection gain error detection unit 11a outputs the W-phase gain error Er_iws.

[0187] In the current detection gain error detection unit 11a, after the phase determination unit 11a1 determines that the electrical angle θre has reached a preset value, it outputs a sample and hold control signal t_w.

[0188] The sample-and-hold control signal t_w is output at a timing when N in equation (17) with respect to the electric angle θre is even.

[0189] The second sample-and-hold unit 11a3 samples and holds the d-axis current observation value id at a timing when the sample-and-hold control signal t_w is input. Therefore, the second sample-and-hold unit 11a3 generates a positive W-phase gain error Er_iws with a multiplier relative to the error β preset and then outputs it.

[0190] exist Figure 18 In the example, to simplify the process, one of the two positive polarity timings was selected.

[0191] Conversely, when motor 1 operates at extremely low speeds, the detection sampling period of the current detection gain error signal is sometimes shortened. In this case, such as Figure 19In the example, the maximum number of samples within one cycle of the electric angle can be set to 2.

[0192] exist Figure 19 In the process, the current detection gain error detection unit 11a accepts the input of the electrical angle θre and the d-axis current observation value id. The current detection gain error detection unit 11a outputs the W-phase gain error Er_iws.

[0193] In the current detection gain error detection unit 11a, after determining that the electrical angle θre has reached a preset value, the phase determination unit 11a1 outputs a sample-and-hold control signal t_w and a polarity specification signal p / n.

[0194] The polarity specification signal p / n switches to H or L when N in equation (17) is an integer. For example, the polarity specification signal p / n becomes H when N is even. For example, the polarity specification signal p / n becomes L when N is odd.

[0195] The second sample-and-hold unit 11a3 samples and holds the d-axis current observation value id at a timing when N in equation (17) becomes an integer. During this time, while the gain error signal is of opposite polarity, the polarity reversal unit 11a7 outputs the polarity-reversed signal. In this case, the switching unit 11a8 selects the polarity-reversed signal. As a result, the detection polarity of the W-phase gain error Er_iws becomes positive.

[0196] Next, use Figure 20 This shows an example of the action of the sample-and-hold control signal t_w and the polarity specification signal p / n relative to the electrical angle.

[0197] Figure 20 A diagram showing an example of the operation of the sampling and holding control signal and the polarity specification signal of the control device of the three-phase AC rotating machine in Embodiment 1 relative to the electrical angle.

[0198] exist Figure 20 In this context, the sample-and-hold control signal t_w is a signal that rises from 0 to 1 when N in equation (17) with respect to the electrical angle θre is an integer. The sample-and-hold control signal t_w is supplied to the second sample-and-hold section 11a3 on the rising edge.

[0199] Next, use Figure 21 The current detection gain correction control calculation unit 12a will be explained.

[0200] Figure 21 This is a block diagram of the current detection gain correction control calculation unit of the control device for the three-phase AC rotating machine in Embodiment 2.

[0201] exist Figure 21In the middle, after receiving the input of the W-phase gain error er_iws, which is the output of the current detection gain error detection unit 11a, the second amplifier 12a3 outputs the W-phase gain error er_iws at a preset multiplier.

[0202] Switch 12a6 selects whether the W-phase gain correction control is ON or OFF. The control signal for switch 12a6 is CT_gain_tune. When switch 12a6 is ON, it outputs the signal after selecting the signal from amplifier 12a3. When switch 12a6 is OFF, it outputs the signal after selecting 0.

[0203] The second integrator 12a4 takes the output of the second amplifier 12a3 as input and integrates it at a preset sampling rate. The second initial value is 1 during initial adjustment. When the second initial value is not in the initial adjustment range, it is set to the convergence value of the second integrator 124 from the previous operation. The output of the second integrator 124 is the gain imbalance correction value cor_iws for phase W.

[0204] The gain imbalance correction value cor_iws of phase W is input to the three-phase current calculation unit 10a. As a result, the gain-corrected current detection values ​​i'us and i'w are obtained. Thus, the three-phase current calculation unit 10a, the three-phase-dq conversion unit 4, the current detection gain error detection unit 11a, and the current detection gain correction control calculation unit 12a form a feedback control loop that functions in such a way that the gain error er_iws detected by the current detection gain error detection unit 11a becomes zero.

[0205] According to the above-described implementation method 2, the same effect as the implementation method is obtained.

[0206] Implementation method 3.

[0207] Figure 22 This is a block diagram of the first example of the control device for the three-phase AC rotating machine in Embodiment 3. Figure 23 This is a block diagram of the second example of the control device for the three-phase AC rotating machine in Embodiment 3. Furthermore, parts that are the same as or equivalent to those in Embodiment 1 are labeled with the same reference numerals. Descriptions of these parts are omitted.

[0208] In implementation method 3, even in the d-axis current command value id * Even when the flux is non-zero in applications such as weak flux control, the control device 20 can still function effectively.

[0209] In applications such as flux weakening control, the d-axis current command value id is used. *When set to non-zero, the d-axis current observation value id becomes non-zero. At this time, through the current control system, even without current detection gain error, the d-axis current observation value id follows the d-axis current command value id without error. * Therefore, in the absence of current sensing gain error, the d-axis current observation value id becomes the d-axis current command value id. * At this time, the id value serves as the d-axis current command value. * The id error signal id_er, which is the difference between the d-axis current observation value id and the d-axis current observation value id, becomes zero.

[0210] When the control bandwidth of a current control system is wide, the id error signal id_er becomes a signal lacking a DC component of the d-axis current observation value id and becomes a signal with reversed polarity. Therefore, in applications such as flux weakening control, the d-axis current command value id... * If the value is set to non-zero, a signal with the polarity of the id error signal id_er reversed can be used.

[0211] Figure 22 and Figure 1 They are roughly the same. Figure 23 and Figure 13 They are largely the same. Hereinafter, the differences between the current control unit 2 and the current detection gain error detection units 11 and 11a will be explained.

[0212] Figure 24 This is a block diagram of the current control section of the control device for the three-phase AC rotating machine in Embodiment 3. Figure 25 This is a block diagram of the current detection gain error detection unit in the first example of the control device for the three-phase AC rotating machine in Embodiment 3. Figure 26 This is a block diagram of the current detection gain error detection unit in the second example of the control device for the three-phase AC rotating machine in Embodiment 3.

[0213] like Figure 24 As shown, the current control unit 2 outputs the id error signal id_er.

[0214] like Figure 25 As shown, the current detection gain error detection unit 11 accepts the input of the id error signal id_er instead of the input of the d-axis current observation value id. In the current detection gain error detection unit 11, the polarity reversal unit 119 reverses the polarity of the id error signal id_er.

[0215] Although not illustrated, but in relation to Figure 5In the corresponding structure, the current detection gain error detection unit 11 receives the input of the id error signal id_er instead of the input of the d-axis current observation value id. In the current detection gain error detection unit 11, the polarity reversal unit 119 reverses the polarity of the id error signal id_er.

[0216] like Figure 26 As shown, the current detection gain error detection unit 11a accepts the input of the id error signal id_er instead of the input of the d-axis current observation value id. In the current detection gain error detection unit 11a, the polarity reversal unit 119a reverses the polarity of the id error signal id_er.

[0217] Although not illustrated, but in relation to Figure 15 In the corresponding structure, the current detection gain error detection unit 11 also accepts the input of the id error signal id_er instead of the input of the d-axis current observation value id. In the current detection gain error detection unit 11, the polarity reversal unit 119 reverses the polarity of the id error signal id_er. This reverses the switching logic of the switching unit 11a8.

[0218] According to the above-described implementation method 3, even in applications such as weak flux control, the d-axis current command value id * When set to a non-zero value, it can also eliminate current ripple and torque ripple caused by CT gain imbalance.

[0219] Implementation method 4.

[0220] Figure 27 This is a block diagram of the current detection gain error detection unit of the control device for the three-phase AC rotating machine in Embodiment 4. Figure 28 This is a block diagram of a portion of the current detection gain error detection unit of the control device for the three-phase AC rotating machine in Embodiment 4. Furthermore, parts that are the same as or equivalent to those in Embodiment 1 are labeled with the same reference numerals. Descriptions of these parts are omitted.

[0221] In embodiment 4, the control device 20 does not include a current detection gain correction control calculation unit 12. The control device 20 uses the current detection gain error detection unit 11 as a CT gain error sensor. Specifically, the control device 20 determines the presence or absence of current detection gain error for the operating device and measures the amount of error. The control device 20 manually adjusts the measured gain error.

[0222] like Figure 27 As shown, for the current detection gain error detection unit 11, an additional ius is used as the input signal. The current detection gain error detection unit 11 outputs the polarity reversal value -β of the V-phase detection gain error α based on the U-phase and the W-phase detection gain error β based on the U-phase.

[0223] like Figure 27 As shown, the control device 20 includes a normalization unit 30. The normalization unit 30 normalizes the d-axis current observation value id using the three-phase current detection value ius.

[0224] The normalization part 30 normalizes the d-axis current observation value id using the three-phase current detection value ius based on the following equation (19).

[0225] [Formula 19]

[0226]

[0227] The timing detection error α and error β are given by the following equation (20).

[0228] [Formula 20]

[0229]

[0230] The input of the normalized d-axis current observation value id is received by the first sample-and-hold unit 112 and the second sample-and-hold unit 113. The first sample-and-hold unit 112 outputs error α. The second sample-and-hold unit 113 outputs error -β.

[0231] Figure 28 Simulate the left side of equation (20). Figure 28 In the multiplication function block 301, the d-axis current observation value id is set to (-2√2) times. The amplitude (Au) detection unit 302 accepts the input of the three-phase current detection value ius. The amplitude (Au) detection unit 302 outputs the amplitude Au. The multiplication function block 303 sets the output of function block 301 as the numerator. The multiplication function block 303 sets the output of amplitude (Au) detection unit 302 as the denominator.

[0232] According to Embodiment 4 described above, without adding any special functions, the estimation and correction of CT gain imbalance can be easily performed by extracting the required signal from the device.

[0233] Here, the adjustment algorithms in Embodiments 1 to 3 will be explained.

[0234] Figure 29 and Figure 30 This is a flowchart illustrating the adjustment algorithm executed by the control device of the three-phase AC rotating machine in Embodiments 1 to 3.

[0235] In embodiments 1 to 3, two key technologies are crucial for CT gain imbalance correction control. The first key technology is current detection gain error detection technology. The corresponding functional block is the current detection gain error detection unit 11. The second key technology is closed-loop current gain correction control technology. The corresponding functional block is the current detection gain correction control arithmetic unit 12.

[0236] In current sensing gain error detection technology, considering the case where the detection sampling period is synchronized with the electrical angle period, it is desirable to implement CT gain imbalance correction control at a rotational speed that can ignore the phase spread caused by sampling. In other words, it is desirable to turn on the control after reaching a preset speed.

[0237] Using a closed-loop current gain correction control technique, after the control is turned on, the determination of whether the control error converges to zero should ideally be performed during a period without abrupt changes in current. In other words, the convergence determination is performed during a period of constant current, ideally during periods of constant acceleration, constant speed, and constant deceleration. During periods other than these, the control is turned off, and the convergence value immediately preceding the OFF position is maintained.

[0238] Figure 29 This is an example of an algorithm that takes into account the operating conditions of current detection gain error detection technology.

[0239] In step S1, it is determined whether the motor speed and the reference phase amplitude are above the preset values. If the determination in step S1 is negative, the process of step S1 is continued. If the determination in step S1 is positive, the process of step S2 is continued.

[0240] In step S2, the initial values ​​of all integrators located inside the current detection gain correction control calculation unit 12 are set to the previously converged values. Then, step S3 is performed. In step S3, the CT gain imbalance correction control is turned on (ON).

[0241] Next, control step S4 is performed. In step S4, it is determined whether the motor speed and the reference phase amplitude are above the preset values. If the determination in step S4 is yes, the processing in step S4 is performed. If the determination in step S4 is no, the processing in step S5 is performed.

[0242] In step S5, the integrator output immediately after the determination in step S4 is negative is stored as the convergence value. Then, step S6 is performed. In step S6, the CT gain imbalance correction control is turned off. Then, step S1 is performed.

[0243] Figure 30This is an example of an algorithm that takes into account the operating conditions of current gain correction control technology.

[0244] In step S11, the CT gain imbalance correction control is turned off. Then, step S12 is performed. In step S12, the timer is initialized. Then, step S13 is performed.

[0245] In step S13, it is determined whether the motor operating mode is during constant acceleration, constant speed, or constant deceleration. If the determination in step S13 is negative, the process in step S11 is performed. If the determination in step S13 is positive, the process in step S14 is performed.

[0246] In step S14, the timer is incremented by 1. Then, step S15 is performed. In step S15, the CT gain imbalance correction control is turned on (ON). Then, step S16 is performed. In step S16, it is determined whether the timer has reached the convergence time of the CT gain imbalance correction control.

[0247] If the determination in step S16 is negative, proceed to step S13. If the determination in step S16 is positive, proceed to step S17.

[0248] In step S17, the integrator output in the current detection gain correction control calculation unit 12, immediately following the determination in step S16, is stored as a convergence value. Then, step S18 is performed. In step S18, the CT gain imbalance correction control is turned off. Then, step S13 is performed.

[0249] If these algorithms are applied, the CT gain imbalance correction control functions properly. As a result, torque ripple, which is the cause of CT gain imbalance, can be effectively suppressed.

[0250] Alternatively, combinations are also possible. Figure 29 and Figure 30 To apply the algorithm.

[0251] Implementation method 5.

[0252] Figure 31 This is a block diagram of the main parts of the control device for the three-phase AC rotating machine in Embodiment 5. Furthermore, parts that are the same as or equivalent to those in Embodiment 1 are labeled with the same reference numerals. Descriptions of these parts are omitted.

[0253] In embodiment 5, the current detection gain error anomaly determination unit 13 accepts inputs of gain imbalance correction value cor_ivs, gain imbalance correction value cor_iws, gain error anomaly determination threshold CT_gain_errthrs1, and gain error anomaly determination threshold CT_gain_errthrs2.

[0254] The gain error anomaly detection threshold CT_gain_errthrs1 is set to a value larger than the gain error anomaly detection threshold CT_gain_errthrs2. For example, the gain error anomaly detection thresholds CT_gain_errthrs1 and CT_gain_errthrs2 are preset based on field results.

[0255] The current detection gain error anomaly determination unit 13 performs anomaly determination when any two of the following conditions 1 to 4 are met.

[0256] Condition 1: cor_ivs≧CT_gain_errthrs1

[0257] Condition 2: cor_iws ≧ CT_gain_errthrs1

[0258] Condition 3: cor_ivs≦CT_gain_errthrs2

[0259] Condition 4: cor_iws ≦ CT_gain_errthrs2

[0260] The current detection gain error anomaly determination unit 13 outputs the gain error anomaly determination result.

[0261] The current detection gain error abnormality output unit 14 outputs an abnormality when the gain error abnormality determination result from the current detection gain error abnormality determination unit 13 indicates an abnormality. The current detection gain error abnormality output unit 14 outputs the abnormality through means such as light, sound, text, image, or communication.

[0262] According to Embodiment 5 described above, the current detection gain error abnormality output unit 14 outputs an abnormality when the gain error abnormality determination result from the current detection gain error abnormality determination unit 13 indicates an abnormality. Therefore, the state of the current detection gain error abnormality can be monitored externally. As a result, appropriate measures can be taken.

[0263] In addition, the various implementation methods can be freely combined, or the implementation methods can be modified or omitted as appropriate.

[0264] Furthermore, in the current control of a three-phase AC rotating machine, as long as the control is performed by processing the current information through coordinate transformation in a rotating coordinate system, both synchronous machines (permanent magnet excitation, winding excitation, etc.) and asynchronous machines (induction machines, etc.) can be applied in principle.

[0265] Industrial utilization

[0266] As described above, the control device for the three-phase AC rotating machine disclosed herein can be used in a system for controlling a three-phase AC rotating machine.

[0267] Explanation of reference numerals in the attached figures

[0268] 1 Motor, 2 Current control unit, 3 DQ-three-phase conversion unit, 4 Three-phase-DQ conversion unit, 5 Power converter, 6A, 6B, 6C Current detectors, 7A, 7B, 7C A / D converters, 8 Rotary position detector, 9 Differential calculation unit, 10 Three-phase current calculation unit, 11 Current detection gain error detection unit, 12 Current detection gain correction control calculation unit, 13 Current detection gain error anomaly determination unit, 14 Current detection gain error anomaly output unit, 20 Control device, 100A Processor, 100B Memory, 200 Hardware.

Claims

1. A control device for a three-phase AC rotating machine, wherein, The control device for the three-phase AC rotating machine includes: A current detector that detects the current in at least two of the three phases of a three-phase AC rotating machine; An A / D converter that performs A / D conversion on the current detected by the current detector; The coordinate transformation unit converts between three-phase coordinates and dq coordinates; The current control unit generates a voltage command value as a control input for voltage based on the difference between a current command value, which is a control input for the current, and a current feedback value, which is a control input for the current. The voltage command value is corrected based on the current command value to eliminate interference between the dq axes. The current feedback value is obtained by the coordinate transformation unit performing a dq coordinate transformation on the current detected by the current detector. A power converter that generates a three-phase voltage based on the voltage command value and supplies the three-phase voltage to the three-phase AC rotating machine; The current detection gain error detection unit defines a preset detection signal from at least two phases of current detected by the current detector as a reference, and detects the inter-phase gain error between the reference phase and the non-reference phase based on the error signal of the d-axis current and the electrical angle; and The current detection gain correction control calculation unit reflects the calculation result of the inter-phase gain error detected by the current detection gain error detection unit into the gain of the current detector in the non-reference phase.

2. The control device for a three-phase AC rotating machine according to claim 1, wherein, The current detection gain correction control calculation unit includes an integrator.

3. A control device for a three-phase AC rotating machine, wherein, The control device for the three-phase AC rotating machine includes: A current detector that detects the current in at least two of the three phases of a three-phase AC rotating machine; An A / D converter that performs A / D conversion on the current detected by the current detector; The coordinate transformation unit converts between three-phase coordinates and dq coordinates; The current control unit generates a voltage command value as a control input for voltage based on the difference between a current command value, which is a control input for the current, and a current feedback value, which is a control input for the current. The voltage command value is corrected based on the current command value to eliminate interference between the dq axes. The current feedback value is obtained by the coordinate transformation unit performing a dq coordinate transformation on the current detected by the current detector. A power converter that generates a three-phase voltage based on the voltage command value and supplies the three-phase voltage to the three-phase AC rotating machine; and The current detection gain error detection unit defines a preset detection signal from the current of at least two phases detected by the current detector as a reference, and detects the interphase gain error between the reference phase and the non-reference phase based on the error signal of the d-axis current and the electrical angle.

4. The control device for a three-phase AC rotating machine according to any one of claims 1 to 3, wherein, The control device for the three-phase AC rotating machine includes: The current detection gain error anomaly determination unit determines whether the inter-phase gain error value between the reference phase and the non-reference phase is above a threshold; and The current detection gain error abnormal output unit outputs an abnormal value when the current detection gain error abnormal determination unit determines that the phase-to-phase gain error value is above the threshold.

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