Rotating electric machine control method and rotating electric machine control system

Abstract

To provide a rotary machine control method and a rotary machine control system that, when using a position detection signal of a rotor as a carrier signal for PWM control, can reduce the harmonics and ripple of current caused by an error in position detection of the rotor.SOLUTION: A rotary electric machine 101 is controlled by a rotary electric machine control system 100 having a first controller 102 and a second controller 103. In the second controller 103, a position detection signal θ of a rotor is acquired. On the other hand, in the first controller 102, a position dependent error ΔθL is acquired. In the first controller 102, a voltage phase α*' according to a drive request is calculated, and the voltage phase α*' is corrected based on the position dependent error ΔθL, thereby a corrected voltage phase α* is calculated. Subsequently, in the second controller 103, a carrier signal in synchronous PWM control is generated by using the position detection signal θ and the corrected voltage phase α*.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a rotating electrical machine control method and a rotating electrical machine control system. [Background technology]

[0002] Patent Document 1 describes a motor control device that corrects the rotor position detected by a resolver and uses it for motor control. This motor control device corrects rotor position detection errors by software processing. More specifically, the motor control device of Patent Document 1 predicts a detection value based on an average value of the time required for a value detected by the resolver to change by a predetermined value, and corrects the actual detection value based on this prediction. In addition, the corrected rotor position information is used for coordinate transformation that converts three-phase motor currents (Iv, Iv, Iw) into d-axis and q-axis currents (Id, Iq), and for coordinate transformation that converts d-axis and q-axis voltage control variables (Vd, Vq) into three-phase voltage control variables (Vu, Vv, Vw). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-283925 A Summary of the Invention [Problem to be solved by the invention]

[0004] One of the synchronous control methods for rotating electrical machines is phase-reference synchronous PWM (Pulse Width Modulation) control, which uses the rotor position detection signal as a carrier signal. However, the rotor position detection signal contains detection errors. For this reason, in phase-reference synchronous PWM control, errors in the rotor position detection signal used as the carrier signal can cause non-negligible harmonics and ripples in the rotating electrical machine current.

[0005] In addition, when performing phase-reference synchronous PWM control, the position detection signal obtained from a position detector such as a resolver is directly input to the PWM signal generator without software processing, so the position detection signal used as the carrier signal is not corrected by software processing. Therefore, when the rotor position detection signal is used as the carrier signal for PWM control, even if the carrier signal contains a rotor position detection error, it is usually not possible to correct this. As a result, phase-reference synchronous PWM control has the problem that it is not possible to reduce harmonics and ripples caused by rotor position detection errors, and it is not possible to completely eliminate the risk of overcurrent and overheating in the rotating electric machine.

[0006] The present invention aims to provide a rotating electric machine control method and a rotating electric machine control system that can reduce current harmonics and ripples caused by rotor position detection errors when a rotor position detection signal is used as a carrier signal for PWM control. [Means for solving the problem]

[0007] One aspect of the present invention is a method for controlling a rotating electric machine by a control system including a first control device that calculates parameters for controlling the driving of the rotating electric machine in response to a drive request for the rotating electric machine, and a second control device that executes synchronous PWM control to generate a PWM signal corresponding to a drive frequency of the rotating electric machine using the parameters and a position detection signal of a rotor of the rotating electric machine. In this method for controlling a rotating electric machine, the second control device acquires the position detection signal of the rotor. Meanwhile, the first control device acquires a position-dependent error that is an error in detecting the position of the rotor and is determined according to the position of the rotor. Furthermore, the first control device calculates a voltage norm that is the norm of a voltage to be applied to the rotating electric machine in response to the drive request and a voltage phase that is the phase of a voltage to be applied to the rotating electric machine in response to the drive request, based on the position detection signal. Then, the first control device calculates a corrected voltage phase by correcting the voltage phase based on the position-dependent error. After that, the second control device generates a carrier signal in the synchronous PWM control using the position detection signal acquired by the second control device and the corrected voltage phase calculated by the first control device. The calculation of the correction voltage phase and the generation of the carrier signal using the correction voltage phase are executed when the modulation rate of the PWM signal is greater than a predetermined threshold value. Effect of the Invention

[0008] According to the rotating motor control method and rotating motor control device of the present invention, when a rotor position detection signal is used as a carrier signal for PWM control, current harmonics and ripples caused by rotor position detection errors can be reduced. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing the configuration of a rotating electrical machine control system. [Diagram 2] FIG. 2 is a block diagram showing the configuration of the vector conversion unit. [Diagram 3] FIG. 3 is a block diagram showing the configuration of the synchronous PWM control unit. [Figure 4] FIG. 4 is a block diagram showing the configuration of the modulation switching determination unit. [Diagram 5]FIG. 5 is a flowchart showing the operation of the rotating electrical machine control system. [Figure 6] FIG. 6 is a timing chart showing the changes over time of the carrier signal and the PWM signal in the basic asynchronous PWM control and synchronous PWM control. [Figure 7] FIG. 7 is an explanatory diagram showing the influence of a position-dependent error contained in a position detection signal and the effect of indirect correction of a carrier signal via a correction voltage phase α*. [Figure 8] FIG. 8 is a block diagram showing a configuration for an error correction unit of the second embodiment to calculate errors relating to position detection. [Figure 9] FIG. 9 is a graph illustrating the relationship between the rotor position indicator array and the position dependent error array. [Figure 10] FIG. 10 is a graph showing the relationship between the true rotor position and the position-dependent error obtained by directly referring to the rotor position index array and the position-dependent error array based on the position detection signal. [Figure 11] FIG. 11 is a graph showing the relationship between the difference array and the error array. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] [First embodiment] Fig. 1 is a block diagram showing a configuration of a rotating electric machine control system 100. As shown in Fig. 1, the rotating electric machine control system 100 is a system for controlling a rotating electric machine 101, and includes a first control device 102, a second control device 103, an inverter 104, and the like.

[0012] The rotating electric machine 101, which is the object of control of the rotating electric machine control system 100, is a motor (electric motor) and / or a generator (electric generator). In either case, the rotating electric machine 101 is composed of a stator, a rotor, etc., not shown. The rotating electric machine control system 100 is mounted on a vehicle such as a hybrid vehicle or an electric vehicle. In this embodiment, the rotating electric machine control system 100 is mounted on an electric vehicle (not shown), and the rotating electric machine 101 is a drive motor for driving the electric vehicle. The rotating electric machine 101 is, for example, an IPM (Interior Permanent Magnet) type three-phase AC motor.

[0013] The first control device 102 is a so-called vehicle controller, and is configured by one or more computers that calculate parameters for controlling the driving of the rotating electric machine 101 in response to a drive request for the rotating electric machine 101. The computer that constitutes the first control device 102 is configured by a CPU (Central Processing Unit), a memory, and the like. The first control device 102 is programmed to calculate parameters for controlling the driving of the rotating electric machine 101 at a predetermined control period τ in response to a drive request for the rotating electric machine 101. That is, the first control device 102 is a calculation device that calculates parameters used for PWM control of the rotating electric machine 101 according to software consisting of one or more programs. The drive request for the rotating electric machine 101 is a request regarding the driving state of the rotating electric machine 101, and is a command that determines the torque of the rotating electric machine 101, or a set of these. The predetermined control period τ in the rotating electric machine control system 100 is, for example, 100 μs.

[0014] The first control device 102 controls the rotating electric machine 101 to output a torque command value T * , and a rotor position detection signal θ of the rotating electric machine 101, etc., parameters for controlling the rotating electric machine 101 by PWM control are calculated. *is calculated by a higher-level vehicle controller or control block (not shown) in accordance with the accelerator opening degree of the electric vehicle, etc. The rotor position detection signal θ is an electrical angle indicating the rotational position of the rotor, is acquired by the second control device 103, and is input to the first control device 102 as appropriate.

[0015] The parameters of the PWM control calculated by the first control device 102 are, for example, three-phase duty command values ​​Duty_u, Duty_v, and Duty_w in asynchronous PWM control, a comparison value Th[n] in synchronous PWM control, and a modulation mode signal Sm for switching between asynchronous PWM control and synchronous PWM control. Details of these various parameters will be described later. The various parameters of the PWM control calculated by the first control device 102 are input to the second control device 103.

[0016] The asynchronous PWM control is a PWM control that uses a PWM signal (hereinafter, referred to as an asynchronous PWM signal) of a predetermined frequency that does not depend on the drive frequency of the rotating electric machine 101. In this embodiment, a triangular wave having a frequency of 1 / 200 μs is used as a carrier signal for the asynchronous PWM control.

[0017] The synchronous PWM control is a PWM control that uses a PWM signal (hereinafter, referred to as a synchronous PWM signal) that corresponds to the drive frequency of the rotating electric machine 101. In the synchronous PWM control, for example, a synchronous PWM signal is generated so as to be proportional to the drive frequency of the rotating electric machine 101. The drive frequency of the rotating electric machine 101 is represented, for example, by a rotor position detection signal θ or other parameters that have a certain correlation with the rotor position detection signal θ. Therefore, the rotor position detection signal θ, the rotor position detection signal θ and the voltage phase α * 'Sum(θ+α * '), or a signal obtained by folding back these signals at a predetermined period, can be used as a carrier signal for synchronous PWM control. In this embodiment, the rotor position detection signal θ and the corrected voltage phase α * ' (correction voltage phase α * ) is used as the carrier signal for synchronous PWM control.

[0018] The second control device 103 generates a drive signal D for driving the switching element in accordance with the PWM control parameters calculated by the first control device 102. uu * ~D wl * to the inverter 104, thereby executing PWM control of the rotating electric machine 101. Specifically, the second control device 103 generates a drive signal D based on duty command values ​​Duty_u, Duty_v, and Duty_w, which are parameters for asynchronous PWM control. uu * ~D wl * to the inverter 104 to execute asynchronous PWM control. The second control device 103 also generates a drive signal D by comparing a comparison value Th[n], which is a parameter for synchronous PWM control, with a carrier signal for synchronous PWM control. uu * ~D wl * is input to an inverter 104 to perform synchronous PWM control.

[0019] In addition, the second control device 103 executes signal processing and the like required for performing asynchronous PWM control and synchronous PWM control. For example, the second control device 103 generates a carrier signal used for these PWM controls.

[0020] The second control device 103 is, for example, a controller configured with a microcomputer or other signal processing circuit device that performs signal processing specialized for executing PWM control. The second control device 103 is, for example, configured separately from the first control device 102. In the rotating electric machine control system 100, the second control device 103 is a sub-control device that performs specific signal processing according to parameters designated by the first control device 102, which is the main control device. In addition, when the rotating electric machine control system 100 is viewed as a whole, the first control device 102 is a general-purpose calculation area that performs various calculations according to software, and the second control device 103 is a circuit for PWM control (so-called PWM timer, etc.) connected to the first control device 102. Therefore, it can be said that the first control device 102 is the CPU area of ​​the rotating electric machine control system 100, and the second control device 103 is the peripheral area (peripheral device) of the rotating electric machine control system 100.

[0021] In this way, since the second control device 103 is a peripheral (peripheral device) domain, the calculations of the first control device 102, which is a CPU domain, do not affect the signal processing in the second control device 103. For example, since the carrier signal used for PWM control is generated in the second control device 103 and used in the second control device 103, the first control device 102 cannot modulate or correct the carrier signal used for PWM control.

[0022] The inverter 104 is driven by the drive signal D outputted from the second control device 103. uu * ~D wl * In this way, the inverter 104 drives the built-in switching element in accordance with the DC voltage of the battery 105 (hereinafter, the battery voltage V dc ) into three-phase AC voltage v u ,v v ,v w As a result, the rotating electric machine 101 receives the torque command value T *The battery 105 is driven to output a torque that is equal to the battery voltage V dc is detected by the DC voltage sensor 106 at any timing.

[0023] <Specific Configuration of First Control Device> The first control device 102 includes a torque control unit 11, a coordinate conversion unit 12, an asynchronous PWM control unit 13, a vector conversion unit 14, a synchronous PWM control unit 15, and a modulation switching determination unit 16.

[0024] The torque control unit 11 determines the torque command value T * , the rotation speed N of the rotating electric machine 101, and the battery voltage V dc , and the d-axis current detection value i of the rotating electric machine 101 d and q-axis current detection value i q Based on this, the d-axis voltage command value v d * and the q-axis voltage command value v q * Calculate the d-axis voltage command value v d * and the q-axis voltage command value v q * is calculated by current vector control (CVC) or voltage phase control (VPC). The calculated d-axis voltage command value v d * and the q-axis voltage command value v q * are input to the coordinate conversion unit 12 and the vector conversion unit 14.

[0025] The coordinate conversion unit 12 converts the pre-read position θ L Based on this, the d-axis voltage command value v d * and the q-axis voltage command value v q * The three-phase voltage command value v u * ,v v * ,v w *This conversion is performed according to the following formula (1).

[0026]

number

[0027] The asynchronous PWM control unit 13 outputs a three-phase voltage command value v u * ,v v * ,v w * and the battery voltage V dc Based on these, the second control device 103 calculates duty command values ​​Duty_u, Duty_v, and Duty_w, which are parameters for asynchronous PWM control. The duty command value Duty_u for the U phase is calculated according to the following equation (2). The same applies to the duty command values ​​Duty_v and Duty_w for the V and W phases. The duty command values ​​Duty_u, Duty_v, and Duty_w are expressed in units of percentages (%). The duty command values ​​Duty_u, Duty_v, and Duty_w for each phase calculated by the asynchronous PWM control device 13 are input to the second control device 103.

[0028]

number

[0029] The vector conversion unit 14 converts the d-axis voltage command value v d * and the q-axis voltage command value v q * Based on this, the voltage norm V, which is a parameter of the synchronous PWM control, a * and voltage phase α * Calculate the voltage norm V a * represents the norm of the voltage to be applied to the rotating electric machine 101 in response to a drive request. Similarly, the voltage phase α * ' represents the phase of the voltage to be applied to the rotating electric machine 101 in response to a drive request. LBased on the voltage phase α * By correcting , the correction voltage phase α * Therefore, the vector conversion unit 14 calculates the d-axis voltage command value v d * , q-axis voltage command value v q * , and the position-dependent error Δθ L The input is the voltage norm V a * and the correction voltage phase α * ' is output. The position-dependent error Δθ L is an error in rotor position detection and depends on the rotor position. L is obtained by the error generating unit 20, which will be described later.

[0030] 2 is a block diagram showing the configuration of vector conversion unit 14. As shown in FIG 2, vector conversion unit 14 includes a voltage norm calculation unit 31, a voltage phase calculation unit 32, and a voltage phase correction unit 33.

[0031] The voltage norm calculation unit 31 calculates the voltage norm V a * In addition, the voltage phase calculation unit 32 calculates the voltage phase α * Calculate '.

[0032]

number

[0033] The voltage phase correction unit 33 is composed of, for example, a subtraction unit 34, and subtracts the voltage phase α * ' to the position-dependent error Δθ L By subtracting, the correction voltage phase α * The voltage phase correction unit 33 calculates the voltage phase α * ' to the position-dependent error Δθ L Instead of subtracting the position-dependent error Δθ L Voltage phase α *By adding, multiplying, dividing, or calculating according to other functions, the correction voltage phase α * can be calculated.

[0034] The synchronous PWM control unit 15 controls the voltage norm V a * , and battery voltage V dc Based on this, a comparison value Th[n], which is a parameter of the synchronous PWM control, is acquired. The comparison value Th[n] is one or more threshold values ​​that are compared with the carrier signal in order to set the on / off timing of the synchronous PWM signal in the synchronous PWM control. That is, in the synchronous PWM control, the on / off of the PWM signal is set by a compare match between the comparison value Th[n] and the carrier signal. The comparison value Th[n] acquired by the synchronous PWM control unit 15 is input to the second control device 103. Note that "n" is an integer, and is an even number in the normal case where there is no folding back of the carrier signal.

[0035] 3 is a block diagram showing the configuration of the synchronous PWM control unit 15. As shown in FIG. 3, the synchronous PWM control unit 15 includes a modulation factor calculation unit 35 and a comparison value table .

[0036] The modulation factor calculation unit 35 calculates the voltage norm V a * and the battery voltage V dc That is, the modulation factor M is set according to a drive request for the rotating electric machine 101. Specifically, the modulation factor M is calculated according to the following formula (4).

[0037]

number

[0038] The comparison value table 36 is a table that stores a comparison value Th[n] in association with each modulation factor M. Therefore, the synchronous PWM control unit 15 functions as a comparison value acquisition unit that acquires the comparison value Th[n] corresponding to the modulation factor M by referring to the comparison value table 36. The comparison value Th[n] is determined in advance for each modulation factor M by an experiment or a numerical calculation using SHE (specified harmonic elimination method) so as to suppress harmonic currents and ripples of the rotating electric machine 101. However, the comparison value Th[n] is a basic comparison value on the premise that the rotor position detection signal θ is compared with a carrier signal in an ideal state in which no error is substantially included. In other words, the comparison value Th[n] determines the on / off phase of the synchronous PWM signal with respect to the carrier signal in the ideal state.

[0039] In this embodiment, the comparison value table 36 stores 10 comparison values ​​Th[1] to Th

[10] for each modulation factor M. Therefore, the synchronous PWM control of this embodiment can generate a synchronous PWM signal including up to five pulses per one period of the electrical angle (position detection signal θ) that is the carrier signal. Note that in this embodiment, the comparison value Th[n] is common to each of the UVW phases.

[0040] The modulation switching determination unit 16 (see FIG. 1) determines the voltage norm V a * and the battery voltage V dc Based on this, it is determined whether the rotating electric machine 101 should be driven by asynchronous PWM control or synchronous PWM control. The determination result of the modulation switching determination unit 16 is input to the second control device 103 as a modulation mode signal Sm. The modulation mode signal Sm is a command that specifies the modulation method of the PWM signal to be either asynchronous PWM control or synchronous PWM control.

[0041] Fig. 4 is a block diagram showing the configuration of the modulation switching determination unit 16. As shown in Fig. 4, the modulation switching determination unit 16 includes a modulation factor calculation unit 37 and a modulation method selection unit .

[0042] The modulation factor calculation unit 37 is configured similarly to the modulation factor calculation unit 35 included in the synchronous PWM control unit 15. That is, the modulation factor calculation unit 37 calculates the voltage norm V a * and the battery voltage V dc Based on this, the modulation factor M of the synchronous PWM signal is calculated according to the above-mentioned equation (4).

[0043] The modulation method selection unit 38 selects the modulation method of the PWM signal from either asynchronous PWM control or synchronous PWM control by comparing the modulation rate M with a predetermined threshold. In this embodiment, the modulation method selection unit 38 selects the modulation method by providing hysteresis to the switching between the asynchronous PWM control and the synchronous PWM control as shown in Table 1 below. Specifically, when the asynchronous PWM control is being performed, if the modulation rate M exceeds 1.0 and control in the so-called overmodulation region or square wave region is required, the modulation method selection unit 38 selects the synchronous PWM control. On the other hand, when the synchronous PWM control is being performed, if the modulation rate M falls below 0.9 and control in the so-called normal modulation region is sufficient, the modulation method selection unit 38 selects the asynchronous PWM control. Therefore, when switching from the asynchronous PWM control to the synchronous PWM control, "1.0" is the predetermined threshold to be compared with the modulation rate M. Also, when switching from the synchronous PWM control to the asynchronous PWM control, "0.9" is the predetermined threshold to be compared with the modulation rate M. That is, the rotating electrical machine control system 100 has an asynchronous PWM control mode in which asynchronous PWM control is performed and a synchronous PWM control mode in which synchronous PWM control is performed, and the asynchronous PWM control mode and the synchronous PWM control mode are switched depending on whether or not the modulation factor M exceeds a predetermined threshold. In this embodiment, the synchronous PWM control mode is performed when the modulation factor M is greater than the predetermined threshold.

[0044] [Table 1]

[0045] In addition to the above, the first control device 102 includes an error correction unit 17, a coordinate conversion unit 18, a look-ahead compensation unit 19, an error generation unit 20, and a rotation speed calculation unit 21 (see FIG. 1).

[0046] The error correction unit 17 acquires the rotor position detection signal θ from the second control device 103. Then, the error correction unit 17 corrects the error included in the position detection signal θ to obtain a corrected position detection signal θ c Calculate the following.

[0047] The errors included in the position detection signal θ include a first-order error, a second-order error, and a structure-related order error. The first-order error is an error that varies first with respect to the electrical angle (position detection signal θ). The second-order error is an error that varies second with respect to the electrical angle (position detection signal θ). The structure-related order error is an error caused by the structure of the rotating electric machine 101 and the structure of the resolver 22 that detects the position of the rotor of the rotating electric machine 101. More specifically, the structure-related order error is an error that varies with respect to the electrical angle (position detection signal θ) at an order depending on the number of pole pairs of the rotating electric machine 101 and the number of teeth of the stator of the resolver 22 (hereinafter referred to as the resolver stator). All of these errors included in the position detection signal θ vary depending on the position (electrical angle) of the rotor of the rotating electric machine 101. Therefore, some or all of these errors are, in a broad sense, position-dependent errors.

[0048] The position-dependent error Δθ calculated by the error correction unit 17 and the position-dependent error Δθ used in the synchronous PWM control unit 15, etc. L are common in that they vary according to the position of the rotor of the rotating electrical machine 101, but they are different. Specifically, the position-dependent error Δθ calculated by the error correction unit 17 is calculated based on the position detection signal θ. On the other hand, the position-dependent error Δθ used in the synchronous PWM control unit 15, etc. L As will be described later, the look-ahead position θ L Therefore, in the following, the position-dependent error Δθ calculated by the error correction unit 17 is simply referred to as the "error Δθ", and the position-dependent error Δθ used in the synchronous PWM control unit 15, etc. is simply referred to as the "error Δθ". L This is distinguished from the above.

[0049] In this embodiment, the error correction unit 17 calculates the error Δθ according to the following equation (5). Then, the error correction unit 17 subtracts the error Δθ from the position detection signal θ as shown in the following equation (6) to obtain a corrected position detection signal θ c Calculate the following.

[0050]

number

[0051] The first term on the right side of equation (5) is a first-order error. That is, the first-order error can be expressed as a sine wave of amplitude A1 and reference phase δ1 with respect to the electrical angle (position detection signal θ). However, the first-order error may be expressed in a form in which the phase is offset based on the rotation speed N and the control period τ. The first-order error may also be expressed as a cosine wave.

[0052] The second term on the right side of equation (5) is a second-order error. That is, the second-order error can be expressed as a sine wave with amplitude A2 and reference phase δ2 with respect to the electrical angle (position detection signal θ). The second-order error may be expressed in a form in which the phase is offset based on the rotation speed N and the control period τ, or may be expressed as a cosine wave.

[0053] The third term on the right-hand side of equation (5) is the structural order error. If the number of pole pairs of the rotating electric machine 101 is "p" and the number of teeth of the resolver stator is "m", the structural order error appears at the order of m / p with respect to the electrical angle (position detection signal θ). In this embodiment, the number of pole pairs of the rotating electric machine 101 is 4, and the number of teeth of the resolver stator is 10. Therefore, the structural order error in this embodiment varies at the order of 2.5 with respect to the electrical angle (position detection signal θ). Therefore, the structural order error appears at the order of m / p with respect to the electrical angle (position detection signal θ). 2.5 and the reference phase δ 2.5 The structure-related order error may be expressed in a form in which the phase is offset based on the rotation speed N and the control period τ, or may be expressed as a cosine wave.

[0054] Therefore, as shown in the formula (5), the error Δθ in this embodiment is the amplitudes A1, A2, and A3 of the first-order error, the second-order error, and the structure-related order error. 2.5 and reference phases δ1, δ2, δ 2.5 The signal is obtained by a calculation of synthesizing a sine wave or a cosine wave based on

[0055] Amplitudes A1, A2, A of first-order error, second-order error, and structure-induced order error 2.5 and reference phases δ1, δ2, δ 2.5 can be obtained in advance at the time of manufacturing or shipping the rotating electrical machine control system 100. For example, the amplitudes A1, A2, A 2.5 and each reference phase δ1, δ2, δ 2.5 can be obtained for each rotation speed N of the rotating electrical machine 101 by performing fast Fourier transform processing (FFT processing) on ​​the position detection signal θ.

[0056] In this embodiment, as in the above formula (5), the sum of the first-order error, the second-order error, and the structure-related order error is taken as the error Δθ, but any one of the first-order error, the second-order error, and the structure-related order error may be taken as the error Δθ. Also, the error Δθ may be calculated by a partial combination of the first-order error, the second-order error, and the structure-related order error. In addition, similar to the first-order error and the second-order error, an error that varies at the third or higher order with respect to the electrical angle (position detection signal θ) may be taken into consideration.

[0057] The coordinate conversion unit 18 converts the corrected position detection signal θ c Based on this, the three-phase current detection value is converted into the d-axis current detection value i d and q-axis current detection value i q The current sensor 23 detects at least two-phase currents at the output terminal of the inverter 104. In this embodiment, the current sensor 23 detects a U-phase current and a V-phase current. Therefore, in this embodiment, the coordinate conversion unit 18 converts the U-phase current detection value i u and V phase current detection value i v , the d-axis current detection value i d and q-axis current detection value iq Convert the d-axis current detection value i d and q-axis current detection value i q is used in the torque control section 11 as described above.

[0058]

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[0059] The look-ahead compensation unit 19 takes into consideration the control period τ and the like, and calculates a corrected position detection signal θ based on the rotation speed N. c By further compensating for this, the compensated position detection signal θ c (Hereinafter, look-ahead position θ L In this embodiment, since the control period τ is 100 μs, the d-axis voltage command value v calculated by the torque control unit 11 is calculated as d * and the q-axis voltage command value v q * The voltage based on the above is applied to the rotating electric machine 101 from about 100 μs to about 200 μs later. Therefore, the look-ahead compensation unit 19 estimates the rotor position 150 μs later, which is the intermediate value between these two. Specifically, the look-ahead compensation unit 19 calculates the corrected position detection signal θ c Compensate for the look-ahead position θ L In the formula (8), “p” is the number of pole pairs of the rotating electrical machine 101. L is used in the coordinate conversion unit 12 and the error generation unit 20 described above.

[0060]

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[0061] The error generator 20 detects the read-ahead position θ L The position-dependent error Δθ L Specifically, the error generator 20 performs a calculation to generate a position-dependent error Δθ L That is, the error generator 20 generates a position-dependent error Δθ LIt functions as a position-dependent error acquisition unit that acquires

[0062]

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[0063] Equation (9) uses the read-ahead position θ instead of the position detection signal θ. L The point where the look-ahead position θ L The position-dependent error Δθ L This is the same as the above formula (5), except that the first term on the right side is the look-ahead position θ L The second term on the right hand side is the look-ahead position θ L Similarly, the third term on the right-hand side is the second-order error corresponding to the look-ahead position θ L Therefore, each term in the formula (9) may be expressed in a form in which the phase is offset based on the rotation speed N and the control period τ, or may be expressed as a cosine wave. In addition, the amplitudes A1, A2, and A3 of the first-order error, second-order error, and structure-related order error are 2.5 and reference phases δ1, δ2, δ 2.5 is the same as that used in equation (5).

[0064] The position-dependent error Δθ generated by the error generating unit 20 L As described above, the correction voltage phase α * Used in the calculation of

[0065] The rotation speed calculation unit 21 calculates the corrected position detection signal θ c Specifically, the rotation speed calculation unit 21 calculates the rotation speed N [rpm] of the rotating electrical machine 101 based on the corrected position detection signal θ c The amount of change per unit time of the corrected position detection signal θ c is converted into the rotation speed N. The rotation speed N is used by the torque control unit 11, the coordinate conversion unit 18, and the look-ahead compensation unit 19, as described above.

[0066]

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[0067] <Specific Configuration of the Second Control Device> The second control device 103 includes an asynchronous PWM signal generator 41, a synchronous PWM signal generator 42, a PWM output switch 43, and an ABZ counter 44 (see FIG. 1).

[0068] The asynchronous PWM signal generator 41 uses the three-phase duty command values ​​Duty_u, Duty_v, and Duty_w input from the asynchronous PWM control unit 13 of the first control device 102 to generate an asynchronous PWM signal D by a so-called triangular wave comparison method. uua * ~D wla * In the triangular wave comparison method, a triangular wave having a predetermined frequency independent of the drive frequency (position detection signal θ) of the rotating electric machine 101 is used as a carrier signal. More specifically, the asynchronous PWM signal generator 41 generates a triangular wave carrier signal C based on three-phase duty command values ​​Duty_u, Duty_v, and Duty_w. a Asynchronous PWM signal D uua * ~D wla * Generate.

[0069] In asynchronous PWM control, the arrangement interval of the pulses in the asynchronous PWM signal is limited to the control period τ. uua * ~D wla * The first subscript "u", "v", or "w" represents each phase, UVW. The second subscript "u" or "l" represents the upper arm element ("u") or the lower arm element ("l") of the inverter 104. The third subscript "a" represents an asynchronous PWM signal.

[0070] The synchronous PWM signal generator 42 generates a carrier signal used in the synchronous PWM control based on the drive frequency (position detection signal θ) of the rotating electric machine 101. That is, the synchronous PWM signal generator 42 functions as a carrier signal generator that generates a carrier signal in the synchronous PWM control based on the position detection signal θ and the like. The synchronous PWM signal generator 42 also generates a synchronous PWM signal D by a compare match between a comparison value Th[n] input from the synchronous PWM control unit 15 of the first control device 102 and the generated carrier signal. uus * ~D wls * Generate.

[0071] In particular, in this embodiment, the synchronous PWM signal generator 42 generates a correction voltage phase α * Using the above, the carrier signal C of each UVW phase is calculated according to the following equation (11). us ,C vs ,C ws Generate.

[0072]

number

[0073] In the synchronous PWM control, the arrangement interval of the pulses in the synchronous PWM signal is almost independent of the control period τ and can be adjusted substantially arbitrarily. Therefore, when the rotating electric machine 101 is driven in the overmodulation region and the rectangular wave region where the number of pulses is limited, the synchronous PWM control has an advantage over the asynchronous PWM control in that it is easier to reduce harmonics and ripples in the current. In addition, the synchronous PWM signal D uus * ~D wls * The first subscript "u", "v", or "w" represents each phase, UVW. The second subscript "u" or "l" represents the upper arm element ("u") or the lower arm element ("l") of the inverter 104. The third subscript "s" represents a synchronous PWM signal.

[0074] The PWM output switch 43 switches the asynchronous PWM signal D according to the modulation mode signal Sm input from the modulation switching determination unit 16. uua * ~D wla * or synchronous PWM signal D uus * ~D wls * Then, the PWM output switch 43 outputs the selected PWM signal as a driving signal D for the switching element. uu * ~D wl * to the inverter 104.

[0075] The ABZ counter 44 samples the up counter pulse A, the down counter pulse B, and the origin signal pulse Z input from the resolver digital converter integrated circuit (RDIC) 24 every control period τ. In this way, the ABZ counter 44 measures the electrical angle of the rotor, i.e., the position detection signal θ. Therefore, the ABZ counter 44 is a position detection signal acquirer that acquires the rotor position detection signal θ. The position detection signal θ is directly input to the synchronous PWM signal generator 42 in the second control device 103 to generate a carrier signal for synchronous PWM control. In addition, the position detection signal θ is input to the error correction unit 17 of the first control device 102.

[0076] The resolver digital conversion circuit 24 outputs an excitation signal to the resolver 22, and receives a modulation signal from the resolver 22. The resolver digital conversion circuit 24 outputs an up counter pulse A, a down counter pulse B, and an origin signal pulse Z to the ABZ counter 44 based on the excitation signal and the modulation signal. In addition, in the rotating electric machine control system 100, an encoder other than the resolver 22 can be used to detect the position of the rotor. When an encoder other than the resolver 22 is used, the specific configuration for measuring the position detection signal θ can be appropriately changed depending on the encoder to be used.

[0077] <effect> The operation of the rotating electrical machine control system 100 configured as above will now be described.

[0078] 5 is a flowchart showing the operation of the rotating electric machine control system 100. As shown in FIG. 5, in step S101, the ABZ counter 44 of the second control device 103 acquires a position detection signal θ indicating the position of the rotor of the rotating electric machine 101. At this time, when the rotating electric machine 101 is controlled by synchronous PWM control, the position detection signal θ is directly input from the ABZ counter 44 to the synchronous PWM signal generator 42 in the second control device 103, and the carrier signal C for synchronous PWM control is generated. us ,C vs ,C ws is generated.

[0079] In step S102, the current detection value i u ,i v Then, in step S103, the error correction unit 17 of the first control device 102 corrects the position detection signal θ based on the error Δθ to obtain a corrected position detection signal θ c In step S104, the rotation speed calculation unit 21 of the first control device 102 calculates the corrected position detection signal θ c In step S105, the coordinate conversion unit 18 of the first control device 102 calculates the rotation speed N based on the corrected position detection signal θ c Based on this, the current detection value i u ,i v The d-axis current detection value i d and q-axis current detection value i q Furthermore, in step S106, the look-ahead compensation unit 19 of the first control device 102 converts the corrected position detection signal θ c Further compensate for the look-ahead position θ L Calculate.

[0080] After that, in step S107, the torque control unit 11 of the first control device 102 calculates the torque command value T * , the rotation speed N of the rotating electric machine 101, and the battery voltage Vdc , and the d-axis current detection value i of the rotating electric machine 101 d and q-axis current detection value i q This performs torque control calculation based on the d-axis voltage command value v d * and the q-axis voltage command value v q * In step S108, the modulation switching determination unit 16 of the first control device 102 determines whether the rotating electric machine 101 is to be controlled by asynchronous PWM control or synchronous PWM control, and outputs a modulation mode signal Sm indicating the determination result to the PWM output switch 43 of the second control device 103.

[0081] In order to control the rotating electric machine 101 by synchronous PWM control (step S109: YES), in step S110, the vector conversion unit 14 of the first control device 102 converts the voltage norm V a * and voltage phase α * Furthermore, the synchronous PWM control unit 15 of the first control device 102 acquires the comparison value Th[n] in step S111 and calculates the position-dependent error Δθ L Furthermore, in step S113, the synchronous PWM control unit 15 of the first control device 102 calculates the position dependent error Δθ by the voltage phase correction unit 33. L Using the voltage phase α * This corrects the correction voltage phase α * is calculated.

[0082] In addition, in order to control the rotating electric machine 101 by asynchronous PWM control (step S109: NO), in step S115, the coordinate conversion unit 12 of the first control device 102 converts the d-axis voltage command value v d * and the q-axis voltage command value v q * The three-phase voltage command value v u * ,v v * ,v w *Then, in step S116, the asynchronous PWM control section 13 of the first control device 102 calculates the duty command values ​​Duty_u, Duty_v, and Duty_w, which are parameters for asynchronous PWM control.

[0083] Therefore, when the execution of the synchronous PWM control is set by the modulation mode signal Sm, in step S114, the second control device 103 calculates the comparison value Th[n] and the correction voltage phase α * A carrier signal C generated using us ,C vs ,C ws When the modulation mode signal Sm is set to execute asynchronous PWM control, the second control device 103 controls the duty command values ​​Duty_u, Duty_v, and Duty_w and the triangular wave carrier signal C in step S117. a Asynchronous PWM control is performed based on the compare match.

[0084] 6 is a timing chart showing the change over time of the basic carrier signal and PWM signal in asynchronous PWM control and synchronous PWM control. FIG. 6(A) shows the change over time of the basic carrier signal and PWM signal in asynchronous PWM control and synchronous PWM control in the case of a triangular wave carrier signal C a The amplitude of the duty command value Duty_u and the asynchronous PWM signal D uua * The same applies to the V-phase and W-phase. FIG. 6B shows an example of the synchronous PWM control according to this embodiment, in which the carrier signal C of the U-phase is us , a comparison value Th[n] common to each phase, and a synchronous PWM signal D of the U phase uus * The same is true for the V and W phases.

[0085] As shown in Figure 6(A), the carrier signal C of the asynchronous PWM control ais a triangular wave that repeats peaks and valleys with a period of twice the control period τ (2τ) and does not depend on the drive frequency (position detection signal θ) of the rotating electric machine 101. Furthermore, interrupts to control calculations such as torque control calculations and updates of parameters according to the results of these control calculations are performed every control period τ. For this reason, for example, the duty command value Duty_u determined as a result of the torque control calculation at time T1, shown by hatching, is reflected at time T2. Similarly, the duty command value Duty_u determined as a result of the torque control calculation at time T2 is reflected at time T3. Then, the carrier signal C a When the duty command value Duty_u or more is reached, the asynchronous PWM signal D uua * is turned on ("1"), and the carrier signal C a When the duty command value Duty_u or less is reached, the asynchronous PWM signal D uua * will be off ("0").

[0086] As shown in FIG. 6(B), the carrier signal C us is a so-called sawtooth wave, and in this embodiment, the position detection signal θ and the correction voltage phase α * The carrier signal C of the synchronous PWM control us is determined by the position detection signal θ, so the carrier signal C of the synchronous PWM control us In principle, the phase of the correction voltage phase α does not coincide with the control period τ. However, the interruption of the control calculation such as the torque control calculation and the update of the parameters according to the results of these control calculations are performed every control period τ, so the comparison value Th[n] is updated every control period τ. * The carrier signal C of the synchronous PWM control is updated every control period τ. us is also corrected (modulated) for each control period τ. For example, the comparison value Th[n] determined as a result of the torque control calculation at time T1, which is indicated by hatching, is reflected at time T2. At the same time, the correction voltage phase α * is updated indirectly, the carrier signal C usSimilarly, the comparison value Th[n] determined as a result of the torque control calculation at time T2 is reflected at time T3. At the same time, the correction voltage phase α * is updated indirectly, the carrier signal C us In synchronous PWM control, the carrier signal C us When the odd-numbered comparison value Th[n] shown by the solid line is reached, the synchronous PWM signal D uus * is on ("1"). Also, the carrier signal C us When the even-numbered comparison value Th[n] shown by the dashed line is reached, the synchronous PWM signal D uus * will be off ("0").

[0087] In FIG. 6B, for convenience, the comparison value Th[n] is depicted as a substantially linear line. However, the comparison value Th[n] varies with the fluctuation of the drive request to the rotating electrical machine 101 and the position-dependent error Δθ L In this embodiment, for simplicity, it is assumed that the drive request to the rotating electric machine 101 does not fluctuate and is constant.

[0088] FIG. 7 shows the position-dependent error Δθ included in the position detection signal θ. L and the effect of the correction voltage phase α * Carrier signal C via us FIG. 7(A) is an explanatory diagram showing the indirect correction effect of the position-dependent error Δθ L A carrier signal C based on an ideal position detection signal θ that does not include us (Hereinafter, ideal carrier signal C us A synchronous PWM signal D is generated by a compare match between the threshold value Th[n] and the comparison value Th[n]. uus * FIG. 7(B) shows the position-dependent error Δθ L A realistic position detection signal θ and an uncorrected voltage phase α * and a carrier signal C based on us (Hereinafter, uncorrected carrier signal C usA synchronous PWM signal D is generated by a compare match between the comparison value Th[n] and the uus * FIG. 7(C) shows the correction voltage phase α * The corrected carrier signal C us (Hereinafter, uncorrected carrier signal C us To distinguish between the corrected carrier signal "C us A synchronous PWM signal D is generated by a compare match between the comparison value Th[n] and the comparison value Th[n]. uus * The dashed line in FIG. 7(C) indicates the position-dependent error Δθ L In addition, in FIG. 7, the U phase is used as an example, but the ideal carrier signal C vs ^, uncorrected carrier signal C vs ' and the corrected carrier signal C vs ', and the ideal carrier signal C of the W phase ws ^, uncorrected carrier signal C ws ' and the corrected carrier signal C ws The same is true for '.

[0089] As shown in FIG. 7(A), the carrier signal in the synchronous PWM control is the ideal carrier signal C us When ^, the comparison value Th[n] shown by the white circle and the ideal carrier signal C us At the intersection of ^, the synchronous PWM signal D uus * This is the drive state that should be achieved in response to a drive request for the rotating electrical machine 101.

[0090] However, the position detection signal θ has a position-dependent error Δθ L Therefore, the carrier signal in synchronous PWM control has a position-dependent error Δθ L Furthermore, the carrier signal in the synchronous PWM control is directly used for generating the carrier signal in the second control device 103 that acquires the position detection signal θ, without going through the first control device 102 that executes calculation processing by software. The rotating electrical machine control system 100 directly calculates the position dependent error Δθ for the position detection signal θ.L No correction can be made to correct the problem.

[0091] Therefore, the carrier signal in synchronous PWM control is usually the uncorrected carrier signal C, as shown in FIG. us and the ideal carrier signal C us ^, the waveform is distorted. And, as shown by the black circle, the uncorrected carrier signal C us The intersection of the comparison value Th[n] and the uncorrected carrier signal C us and the synchronous PWM signal D generated by the compare match of the comparison value Th[n]. uus * is the synchronous PWM signal D to be realized in FIG. uus * Therefore, the driving state corresponding to the driving request for the rotating electric machine 101 is not accurately realized, and the harmonics and ripples of the current flowing through the rotating electric machine 101 may not be sufficiently reduced. us For simplicity, let us use the ideal carrier signal C us ^ is shown with only the first-order error superimposed.

[0092] Therefore, in this embodiment, as shown in FIG. 7C, the voltage phase α * The indirectly corrected carrier signal C us A synchronous PWM signal D is generated by a compare match between ′ and the comparison value Th[n]. uus * In this case, the corrected carrier signal C us ' has the correction voltage phase α * through the position-dependent error Δθ L is reflected, so the corrected carrier signal C us ' is the position dependent error Δθ L In particular, the position-dependent error Δθ L Acquisition of the correction voltage phase α * Since the calculation of is performed every control period τ, the corrected carrier signal Cus ' is the position dependent error Δθ L The corrected carrier signal C shown here varies smoothly with the us ′ indicates the state in which a sinusoidal waveform corresponding to the first-order error is superimposed.

[0093] In this way, the corrected carrier signal C us When using the corrected carrier signal C us The intersection of ′ and the comparison value Th[n] coincides with the time when the intersection (white circle) occurs in the ideal state. Therefore, the corrected carrier signal C us A synchronous PWM signal D generated by a compare match between ′ and the comparison value Th[n] uus * is the synchronous PWM signal D to be realized in FIG. uus * As a result, even if the correction by software calculation does not reach the position detection signal θ, the rotating electric machine 101 is controlled in a substantially ideal driving state in response to a drive request.

[0094] As described above, the rotating electric machine control method according to this embodiment is a rotating electric machine control method that controls the rotating electric machine 101 by the rotating electric machine control system 100 having the first control device 102 that calculates parameters for controlling the drive of the rotating electric machine 101 in response to a drive request for the rotating electric machine 101, and the second control device 103 that executes synchronous PWM control to generate a PWM signal corresponding to the drive frequency of the rotating electric machine 101 using the parameters and a rotor position detection signal θ of the rotating electric machine 101. In this rotating electric machine control method, the second control device 103 acquires the rotor position detection signal θ. Meanwhile, the first control device 102 acquires a position-dependent error Δθ, which is an error in rotor position detection and is determined according to the rotor position. L In addition, the first control device 102 acquires a voltage phase α * Then, in the first control device 102, the position dependent error Δθ L Based on the voltage phase α *By correcting , the correction voltage phase α * Thereafter, the second control device 103 calculates the position detection signal θ acquired by the second control device 103 and the correction voltage phase α * Using the above, the carrier signal (corrected carrier signal C us ′,C vs ′,C ws ′) is generated.

[0095] The position detection signal θ is directly converted into the synchronous PWM control carrier signal C without going through software correction or the like of the first control device 102. us ,C vs ,C ws When using this carrier signal C us ,C vs ,C ws (uncorrected carrier signal) is distorted according to the detection error of the position detection signal θ. However, in the rotating electric machine control method according to the present embodiment, not only the position detection signal θ that is not affected by the correction by the first control device 102, but also the corrected voltage phase α * Using the carrier signal (corrected carrier signal C us ′,C vs ′,C ws Then, the correction voltage phase α * is the original voltage phase α * ′ is the position-dependent error Δθ L Therefore, the correction by the first control device 102 does not directly affect the position detection signal θ acquired and used in the second control device 103, but the correction voltage phase α * Through, the position-dependent error Δθ L Therefore, according to the method for controlling a rotating electric machine according to the present embodiment, the distortion of the carrier signal caused by the position detection signal θ is corrected. L ), the rotating electrical machine 101 is driven in an ideal driving state that should be realized in response to a drive request, and current harmonics and ripples are reduced.

[0096] In particular, the correction voltage phase α * Calculation of the correction voltage phase α * Synchronous PWM signal D using uus * ~D wls * The generation of the synchronous PWM signal D uus * ~D wls * The method is executed when the modulation factor M of the position detection signal θ is greater than a predetermined threshold value. That is, the method of controlling a rotating electric machine according to this embodiment is executed when the modulation factor M is large and control is performed particularly in the overmodulation region or square wave region. Synchronous PWM control in the overmodulation region or square wave region where the modulation factor M is large has the advantage that it is easier to reduce harmonics and ripples in the current than asynchronous PWM control. However, when the position detection signal θ contains a position-dependent error Δθ L If the synchronous PWM control is performed in the overmodulation region or the rectangular wave region, the harmonics and ripples of the current may not be sufficiently reduced. Therefore, as described above, when the synchronous PWM control is performed in at least the overmodulation region or the rectangular wave region, the harmonics and ripples of the current can be more reliably reduced by adopting the rotating electric machine control method according to the present embodiment.

[0097] In the rotating electrical machine control method according to the present embodiment, the position-dependent error Δθ L Acquisition and correction voltage phase α * The calculation of the correction voltage phase α * The position-dependent error Δθ L In this way, the position-dependent error Δθ L and the correction voltage phase α * By updating L Current harmonics and ripples caused by

[0098] In the rotating electrical machine control method according to the present embodiment, the position-dependent error Δθ L The position detection signal θ is corrected based on the c and a position-dependent error Δθ L is the corrected position detection signal θ cThat is, the first control device 102 can perform calculation processing according to software, so the position-dependent error Δθ L is not obtained based on the original position detection signal θ, but based on the corrected position detection signal θ c In this way, in the rotating electrical machine control method according to the present embodiment, the position-dependent error Δθ L , the correction position detection signal θ c Based on this, a particularly accurate position-dependent error Δθ L Therefore, the correction voltage phase α * The accuracy of the calculation is improved, and current harmonics and ripples are reduced with particularly high precision.

[0099] Furthermore, in the rotating electrical machine control method according to the present embodiment, a corrected position detection signal θ c Further compensate for the position-dependent error Δθ L is the compensated position detection signal θ c The look-ahead position θ L In this way, the look-ahead position θ L Based on the position dependent error Δθ L By acquiring the above, a deviation caused by a delay time until the result of the torque control calculation or the like is actually reflected in the rotating electric machine 101 is compensated in advance. Therefore, at the time when the result of the torque control calculation or the like is actually reflected in the rotating electric machine 101, the harmonics and ripples of the current are reduced with particularly high precision.

[0100] In addition, in the rotating electrical machine control method according to the present embodiment, the position-dependent error Δθ L are the amplitudes A1, A2, and A3 of the first-order error, which varies with the rotor electrical angle (position detection signal θ), the second-order error, which varies with the rotor electrical angle, and / or the structural order error, which varies with the rotor electrical angle at an order according to the number of teeth of the resolver stator. 2.5 and reference phases δ1, δ2, δ 2.5 And the position dependent error Δθ L As shown in equation (9), these amplitudes A1, A2, A2.5 and reference phases δ1, δ2, δ 2.5 The signal is obtained by a calculation of synthesizing a sine wave or a cosine wave based on

[0101] Thus, the amplitudes A1, A2, A 2.5 and reference phases δ1, δ2, δ 2.5 The position-dependent error Δθ L Then, the position-dependent error Δθ L In particular, the position-dependent error Δθ L As a result, harmonics and ripples in the current are reduced with particularly high accuracy. In particular, when the structural order error is included in the above calculation, the position-dependent error Δθ due to the installation accuracy of the resolver 22 (for example, the axial eccentricity of the resolver 22, the offset in the axial direction, the deviation in flatness with respect to the axial end face, the number of teeth of the resolver stator, etc.) L This allows for efficient compensation of the effects of the components.

[0102] In the first embodiment, the correction carrier signal C used in the synchronous PWM control us ′,C vs ′,C ws Although the corrected carrier signal C′ is a sawtooth wave, other types of carrier signals may be used in the synchronous PWM control. For example, the corrected carrier signal C us ′,C vs ′,C ws The corrected carrier signal C ′ is folded back at a specified phase (for example, π) to form a triangular wave. us ″,C vs ″,C ws" (not shown) can be used as the carrier signal for synchronous PWM control. Furthermore, the carrier signal may be folded back, for example, every 2π / 3 or every 2π / 4. When a folded carrier signal is used in this way, the number of comparison values ​​Th[n] can be reduced more than when a non-folded carrier signal is used. This saves memory area for holding the comparison values ​​Th[n], and also reduces the calculation load for obtaining the comparison values ​​Th[n]. The effects of saving memory area and reducing calculation load become more pronounced the more the carrier signal is folded back.

[0103] In the first embodiment, the comparison value Th[n] is common to the UVW phases, but the comparison value Th[n] may be set for each UVW phase. In this case, there is an advantage that the degree of freedom of dead time compensation related to the switching of the inverter 104 during synchronous PWM control is improved. As a result of the improved degree of freedom of dead time compensation, high-precision dead time compensation is possible, and current harmonics and ripples are particularly reduced.

[0104] [Second embodiment] In the first embodiment, the error Δθ related to the detection of the position detection signal θ is obtained by calculation according to the formulas (5) and (6), but this is not limiting. As in the second embodiment described below, the error Δθ related to the detection of the position detection signal θ may be obtained by referring to a lookup table.

[0105] Fig. 8 is a block diagram showing a configuration for error correction unit 17 of the second embodiment to calculate error Δθ related to position detection. As shown in Fig. 8, in the second embodiment, first control device 102 stores rotor position index array x[n] and error array y[n] in advance in a memory or the like. Then, error correction unit 17 obtains error Δθ related to detection of position detection signal θ using the position detection signal θ, rotor position index array x[n], and error array y[n].

[0106] The rotor position index array x[n] is a one-dimensional array data that defines the position index by the rotor electrical angle. The error array y[n] is a one-dimensional array data that defines the position detection errors y1 to y n The error array y[n] is a one-dimensional array data that stores the error in correspondence with the rotor position index array x[n]. More specifically, the error array y[n] represents the first-order error, the second-order error, and / or the structure-related order error. The data of the error array y[n] (errors y1 to y n ) is determined in advance by experiments, numerical calculations, etc.

[0107] Fig. 9 is a graph showing the relationship between the rotor position index array x[n] and the error array y[n]. For simplicity, Fig. 9 shows the relationship between the rotor position index array x[n] and the error array y[n] when only a first-order error occurs in the rotor position detection. When a first-order error occurs in the rotor position detection, as shown in Fig. 9, the relationship between the rotor position index array x[n] and the error array y[n] becomes, for example, a sine wave.

[0108] FIG. 10 is a graph showing the relationship between the true rotor position and the error Δθ obtained by directly referring to the rotor position index array x[n] and the error array y[n] based on the position detection signal θ. As shown by the solid line in FIG. 10, if only a first-order error occurs in rotor position detection, the error Δθ should be, for example, a sine wave with respect to the true rotor position. However, as shown by the dashed line in FIG. 10, if the error Δθ is obtained by directly referring to the rotor position index array x[n] and the error array y[n] based on the position detection signal θ, which is the actual detection value, the obtained error Δθ will have a distorted waveform from the original sine wave waveform with respect to the true rotor position. This is because the actual position detection signal θ contains the error Δθ, and a shift occurs in the reference position of the rotor position index array x[n] by the amount of the error Δθ.

[0109] Therefore, the error correction unit 17 in the fourth embodiment is configured to obtain a correct error Δθ with respect to the true rotor position by using the position detection signal θ, the rotor position index array x[n], and the error array y[n]. Specifically, the error correction unit 17 includes a subtraction unit 81 and an LUT 82 which is a one-dimensional lookup table (see FIG. 8).

[0110] The subtraction unit 81 calculates a difference array (x[n]-y[n]), which is a new one-dimensional array, by subtracting the error array y[n] from the rotor position index array x[n]. The LUT 82 is configured to use the difference array (x[n]-y[n]) as an input reference array and the error array y[n] as an output reference array.

[0111] FIG. 11 is a graph showing the relationship between the difference array (x[n]-y[n]) and the error array y[n]. As shown in FIG. 11, the LUT 82 produces an error array y[n], which is an output reference array, that has a waveform distorted from a sine wave for the difference array (x[n]-y[n]), which is an input reference array. This waveform distortion corresponds to the deviation between the solid line and the dashed line in FIG. 10. Therefore, when an error Δθ relating to the detection of the position detection signal θ is obtained by referring to the LUT 82 based on the position detection signal θ, this error Δθ has a correct value with respect to the true rotor position.

[0112] In the second embodiment, the error correction unit 17 corrects the position detection signal θ c When calculating the position-dependent error Δθ, the error Δθ associated with the detection of the position detection signal θ is obtained by the LUT 82. Similarly, the error generating unit 20 also refers to the LUT 82 to calculate the position-dependent error Δθ L The information may be configured to obtain

[0113] Specifically, in the first embodiment, the look-ahead compensation unit 19 calculates the correction position detection signal θ c Using the look-ahead position θ L The error generator 20 calculates the look-ahead position θ L Based on this, the position-dependent error Δθ is calculated according to equation (9). LHowever, the look-ahead compensation unit 19 may be configured so that the pre-correction position detection signal θ is input. In this case, the error generation unit 20 calculates the look-ahead position θ calculated based on the pre-correction position detection signal θ. L That is, the read-ahead position θ including the error Δθ related to the position detection L Based on this, the position-dependent error Δθ L Therefore, the error generator 20 directly references the rotor position index array x[n] and the error array y[n] to obtain the position-dependent error Δθ L , the exact position-dependent error Δθ L may not be able to be obtained.

[0114] Therefore, the pre-read position θ calculated based on the position detection signal θ before correction L Based on the position dependent error Δθ L When calculating the position-dependent error Δθ, the error generator 20 calculates the position-dependent error Δθ in the same manner as in the second embodiment, instead of calculating the equation (9). L That is, similarly to the second embodiment, the error generator 20 uses the rotor position index array x[n] and the error array y[n] to calculate the read-ahead position θ L from the position-dependent error Δθ L In this way, it is preferable to calculate the position-dependent error Δθ L By obtaining the above, the pre-read position θ calculated based on the position detection signal θ before correction is obtained. L Based on the position dependent error Δθ L Even when calculating the position-dependent error Δθ L can be obtained.

[0115] In the second embodiment, the error Δθ and the position-dependent error Δθ L Although an example in which only a first-order error is included is shown, the case in which a second-order error and a structure-related order error are included is also similar to the second embodiment.

[0116] In the second embodiment, the LUT 82 is configured to use the difference array (x[n]-y[n]) obtained by correcting the rotor position index array x[n] with the error array y[n] as the input reference array, and the error array y[n] as the output reference array, but this is not limiting. The LUT 82 may be configured to use the rotor position index array x[n] as the input reference array, and to use the array (e.g., y[n]-x[n]) obtained by correcting the rotor position index array x[n] with the error array y[n] as the output reference array. In this case, too, as in the fourth embodiment, the accurate error Δθ and the position-dependent error Δθ with respect to the true rotor position are calculated. L is obtained.

[0117] As described above, in the rotating electric machine control method according to the second embodiment, the first array data (rotor position index array x[n]) that determines the position index based on the rotor electrical angle and the error Δθ or the position-dependent error Δθ L is determined in advance by the first-order error that varies linearly with respect to the electrical angle of the rotor (position detection signal θ), the second-order error that varies quadratically with respect to the electrical angle of the rotor, and / or the second array data (error array y[n]) that determines the structural order error that varies with respect to the electrical angle of the rotor, with an order corresponding to the number of teeth in the stator of the resolver 22 that detects the position of the rotor. L is obtained by referring to the LUT 82, which uses the first array data (rotor position index array x[n]) corrected by the second array data (error array y[n]) as an input reference array and the second array data (error array y[n]) as an output reference array. L is obtained by referencing an LUT82 that uses the first array data (rotor position index array x[n]) as an input reference array and the second array data (error array y[n]) corrected by the first array data (rotor position index array x[n]) as an output reference array.

[0118] In this way, the error Δθ or the position-dependent error Δθ L In order to obtain a particularly accurate error Δθ and a position-dependent error Δθ LAs a result, the position detection signal θ is subject to an error (position-dependent error Δθ L ), the rotating electrical machine 101 is driven in an ideal driving state that should be realized in response to a drive request, and current harmonics and ripples are particularly reduced.

[0119] Although the embodiments of the present invention have been described above, the configurations described in the above embodiments and the respective modified examples merely represent some of the application examples of the present invention and are not intended to limit the technical scope of the present invention. [Explanation of symbols]

[0120] 11: torque control unit, 13: asynchronous PWM control unit, 14: vector conversion unit, 15: synchronous PWM control unit, 17: error correction unit, 19: look-ahead compensation unit, 20: error generation unit, 22: resolver, 31: voltage norm calculation unit, 32: voltage phase calculation unit, 33: voltage phase correction unit, 36: comparison value table, 41: asynchronous PWM signal generator, 42: synchronous PWM signal generator, 43: PWM output switch, 100: rotating electric machine control system, 101: rotating electric machine, 102: first control device, 103: second control device, 104: inverter, 105: battery

Claims

1. A rotating electric machine control method for controlling a rotating electric machine by a control system including: a first control device that calculates parameters for controlling a drive of the rotating electric machine in response to a drive request for the rotating electric machine; and a second control device that executes synchronous PWM control to generate a PWM signal according to a drive frequency of the rotating electric machine by using the parameters and a position detection signal of a rotor of the rotating electric machine, the method comprising: The second control device acquires the position detection signal of the rotor; In the first control device, a position-dependent error is obtained, which is an error in detecting the position of the rotor and is determined depending on the position of the rotor; a voltage phase that is a phase of a voltage to be applied to the rotating electric machine in response to the drive request, based on the position detection signal, in the first control device; In the first control device, a corrected voltage phase is calculated by correcting the voltage phase based on the position dependent error; In the second control device, a carrier signal in the synchronous PWM control is generated by using the position detection signal acquired by the second control device and the correction voltage phase calculated by the first control device; The calculation of the correction voltage phase and the generation of the carrier signal using the correction voltage phase are executed when a modulation rate of the PWM signal is greater than a predetermined threshold value. A rotating electrical machine control method.

2. 2. A rotating electric machine control method according to claim 1, comprising: generating a corrected position detection signal by correcting the position detection signal based on the position dependent error; The position dependent error is obtained based on the compensated position detection signal; The voltage norm and the voltage phase are calculated based on the corrected position detection signal. A rotating electrical machine control method.

3. 3. A rotating electrical machine control method according to claim 2, comprising: Further compensating the corrected position detection signal based on the rotation speed of the rotor; The position-dependent error is obtained based on the compensated position detection signal; The voltage norm and the voltage phase are calculated based on the compensated position detection signal. A rotating electrical machine control method.

4. A rotating electric machine control method according to any one of claims 1 to 3, the position-dependent error is determined in advance by an amplitude and a reference phase of an error that varies linearly with respect to the electrical angle of the rotor, an error that varies quadratically with respect to the electrical angle of the rotor, and / or an error that varies with respect to the electrical angle of the rotor with an order corresponding to the number of teeth of a stator in a resolver that detects the position of the rotor; The position-dependent error is obtained by computing a sine wave or a cosine wave based on the amplitude and the reference phase. A rotating electrical machine control method.

5. A rotating electric machine control method according to any one of claims 1 to 3, the position-dependent error is predetermined by first array data that defines a position index based on the electrical angle of the rotor, and second array data that defines an error that varies linearly with respect to the electrical angle of the rotor, an error that varies quadratically with respect to the electrical angle of the rotor, and / or an error that varies with respect to the electrical angle of the rotor with an order corresponding to a number of teeth in a stator of a resolver that detects the position of the rotor, The position dependent error is The first array data corrected by the second array data is acquired by referring to a lookup table in which the first array data is an input reference array and the second array data is an output reference array; or The first array data is acquired by referring to a lookup table in which the first array data is an input reference array and the second array data corrected by the first array data is an output reference array. A rotating electrical machine control method.

6. A rotating electric machine control system including: a first control device that calculates parameters for controlling a drive of a rotating electric machine in response to a drive request for the rotating electric machine; and a second control device that executes synchronous PWM control to generate a PWM signal according to a drive frequency of the rotating electric machine by using the parameters and a position detection signal of a rotor of the rotating electric machine, The second control device is A position detection signal acquirer that acquires the position detection signal of the rotor Equipped with The first control device is a position-dependent error acquisition unit that acquires a position-dependent error, which is an error in detecting the position of the rotor and is determined depending on the position of the rotor; a voltage phase calculation unit that calculates a voltage phase, which is a phase of a voltage to be applied to the rotating electric machine in response to the drive request, based on the position detection signal; a voltage phase correction unit that calculates a corrected voltage phase by correcting the voltage phase based on the position dependent error; Equipped with The second control device further includes a carrier signal generator that generates a carrier signal in the synchronous PWM control by using the position detection signal acquired by the position detection signal acquirer and the corrected voltage phase calculated by the voltage phase correction unit, The calculation of the correction voltage phase and the generation of the carrier signal using the correction voltage phase are executed when a modulation rate of the PWM signal is greater than a predetermined threshold value. Rotating electric machine control system.

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