Rotating mechanism control device

Abstract

This rotating machine control device (1) comprises: a voltage applicator (3) for generating a three-phase voltage to be applied to a rotating machine (2); and a controller (4) for controlling the voltage generation operation of the voltage applicator (3) with a first pulse width modulation mode, that is, a pulse width modulation mode in which a carrier wave frequency is not synchronized with the frequency of a voltage command, or with a second pulse width modulation mode, that is, a pulse width modulation mode in which the carrier wave frequency is synchronized with the frequency of the voltage command, wherein the controller (4) selects either the first pulse width modulation mode or the second pulse width modulation mode as a pulse width modulation mode to be used to control the voltage generation operation on the basis of a first carrier wave used to generate a signal for controlling the voltage applicator with the first pulse width modulation mode, a second carrier wave used to generate a signal for controlling the voltage applicator with the second pulse width modulation mode, and an output voltage phase command indicating a phase of an output voltage to the rotating machine.

Description

Technical Field

[0001] The present disclosure relates to a rotating machine control device for controlling a rotating machine.

Background Art

[0002] In order to perform variable speed operation of an alternating current motor (hereinafter referred to as a rotating machine), which is a type of rotating machine, it is necessary to convert the power supplied to the rotating machine into a desired voltage and frequency. An inverter device is used for power conversion. A general inverter device is composed of a main circuit using semiconductor switching elements and a control device for controlling the semiconductor switching elements. The inverter device obtains a desired frequency and voltage by controlling the on / off of the semiconductor switching elements. As a method of switching the semiconductor switching elements, PWM (Pulse Width Modulation) control is widely used.

[0003] The pulses used in PWM control are generated by comparing a command of the voltage to be applied to the rotating machine (hereinafter referred to as a voltage command) with a carrier wave for generating the pulses. For example, a triangular wave is used as the carrier wave. The higher the frequency of the carrier wave, the fewer the harmonics contained in the output pulses, and the lower the harmonic loss when applied to the rotating machine.

[0004] However, when the carrier wave frequency is increased, the number of switchings of the semiconductor switching elements increases, resulting in heat generation due to an increase in switching loss. Therefore, from the viewpoint of thermal design, an upper limit of the carrier wave frequency is determined.

[0005] If the carrier frequency is kept constant regardless of the rotational speed of the rotating machine, the number of switching operations increases when the rotational speed of the rotating machine increases, and it becomes impossible to withstand the heat generation. Therefore, control is performed such that the carrier frequency is kept constant when the rotational speed of the rotating machine is low, and the carrier frequency is changed in synchronization with the frequency of the voltage command when the rotational speed of the rotating machine is high. A PWM method in which the carrier frequency is not synchronized with the frequency of the voltage command is called an asynchronous PWM mode, and a PWM method in which the carrier frequency is synchronized with the frequency of the voltage command is called a synchronous PWM mode (hereinafter, the asynchronous PWM mode may be simply referred to as asynchronous PWM, and the synchronous PWM mode may be simply referred to as synchronous PWM). Some synchronous PWMs employ a plurality of carrier frequencies in order to change the number of pulses included in one cycle of the voltage command.

[0006] When switching the mode of the PWM method (hereinafter referred to as the PWM mode), if the switching is executed without any consideration, vibration (hereinafter referred to as current vibration) occurs in the current flowing through the rotating machine. When current vibration occurs, the armature current, which is the current flowing through the rotating machine, deviates from the allowable current of the semiconductor switching element, and there is a risk that the switching element may be destroyed. In addition, depending on the frequency of the current vibration, there is a possibility of conflicting with the regulation of current harmonics, so it may be necessary to add a filter circuit. Furthermore, since the torque of the rotating machine vibrates in proportion to the current vibration, there is a risk that mechanical vibration and noise of the rotating machine may become a problem.

[0007] Regarding the occurrence of current vibration during such PWM mode switching, various countermeasures have been taken so far. For example, Patent Document 1 discloses a technique of switching between a variable voltage operation method using a pulse width modulation method and a one-dash pulse control method at a phase angle near where the deviation of the center of the locus of the primary magnetic flux of the rotating machine in the stationary coordinate system is minimized.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, the technique described in Patent Document 1 has a problem that it cannot be applied to the switching between asynchronous PWM that operates without synchronization with the voltage phase and synchronous PWM that operates in synchronization with the voltage phase because it switches the PWM mode at a predetermined specific phase.

[0010] This disclosure has been made in view of the above, and an object thereof is to obtain a rotary machine control device capable of suppressing current vibration when switching the PWM mode used for controlling the generation operation of the voltage applied to the rotary machine between asynchronous PWM and synchronous PWM.

Means for Solving the Problems

[0011] In order to solve the above-described problems and achieve the object, a rotary machine control device according to the present disclosure includes a voltage applicator that generates a three-phase voltage applied to the rotary machine, and a first pulse width modulation mode that is a pulse width modulation method in which the carrier frequency is not synchronized with the frequency of the voltage command or a second pulse width modulation mode that is a pulse width modulation method in which the carrier frequency is synchronized with the frequency of the voltage command, and a controller that controls the voltage generation operation by the voltage applicator. The controller is based on a first carrier wave used for generating a signal for controlling the voltage applicator in the first pulse width modulation mode, a second carrier wave used for generating a signal for controlling the voltage applicator in the second pulse width modulation mode, and an output voltage phase command for commanding the phase of the output voltage to the rotary machine, and selects either the first pulse width modulation mode or the second pulse width modulation mode as the pulse width modulation method used for controlling the voltage generation operation. At the same time, when switching the pulse width modulation method used for controlling the voltage generation operation, based on the first carrier wave, the second carrier wave, and the output voltage phase command, detect the timing at which the difference between the interlinkage magnetic flux of the rotating machine when controlling the voltage generation operation in the first pulse width modulation mode and the interlinkage magnetic flux of the rotating machine when controlling the voltage generation operation in the second pulse width modulation mode becomes the smallest, and set the detected timing as the switching timing of the pulse width modulation method. 。

Advantages of the Invention

[0012] The rotary machine control device according to the present disclosure has an effect that it can suppress current vibration when switching the PWM mode used for controlling the generation operation of the voltage applied to the rotary machine between asynchronous PWM and synchronous PWM.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Embodiments for Carrying Out the Invention

[0014] Hereinafter, the rotary electric machine control device according to the embodiment of the present disclosure will be described in detail with reference to the drawings.

[0015] Embodiment 1. Before explaining the details of the rotary electric machine control device according to the present embodiment, first, the current vibration that becomes a problem when switching the PWM mode will be explained.

[0016] Fig. 11 is a diagram showing a first example of current vibration generated when switching the PWM mode. Specifically, it shows an example of current vibration generated when a conventional rotary electric machine control device, which is a comparative example, switches the PWM mode. The current shown in Fig. 11 is obtained by converting the three-phase alternating current of the rotary electric machine into two-phase and performing a rotational coordinate notation (d-q conversion) at the magnetic pole position of the rotary electric machine. When the rotary electric machine currents on the d-axis and q-axis are passed through a band-pass filter (BPF: Band Pass Filter) centered on the frequency of the voltage command, the current vibration at the time of PWM mode switching can be extracted. Note that the first row from the top in Fig. 11 shows the d-axis current, which is the rotary electric machine current on the d-axis, and the second row shows the vibration of the d-axis current (the d-axis current after passing through the BPF). The third row shows the q-axis current, which is the rotary electric machine current on the q-axis, and the fourth row shows the vibration of the q-axis current (the q-axis current after passing through the BPF). The vertical dashed line in the center indicates the timing of switching the PWM mode.

[0017] The cause of the current vibration shown in Fig. 11 will be explained. When the rotary electric machine to be controlled is an interior permanent magnet synchronous motor (IPMSM), the voltage equation on the rotational coordinates is expressed by the following equation (1).

[0018]

Number

[0019] In Equation (1), v d and v q are the voltages applied to the d-axis and q-axis of the IPMSM, respectively, and i d and i q are the currents flowing through the d-axis and q-axis of the IPMSM, respectively. Also, L d and L q are the d-axis inductance and q-axis inductance of the IPMSM, respectively, and φ d and φ q are the d-axis magnetic flux and q-axis magnetic flux of the IPMSM, respectively. Also, φm is the magnet magnetic flux, R is the winding resistance, and ω is the angular frequency of the fundamental wave of the voltage applied to the IPMSM. Note that d / dt represents the differential operation. i d and i q are functions of time. Time is represented by t.

[0020] When Equation (1) is taken as the voltage equation in the transient state immediately after PWM mode switching, and the voltage equation in the steady state is taken as Equation (2) shown below, the differential voltage equation becomes Equation (3) shown below.

[0021]

Number

[0022]

Number

[0023] In Equations (2) and (3), the d-axis current and q-axis current in the steady state are i d ’ and i q ’, and the d-axis magnetic flux and q-axis magnetic flux in the steady state are φ d ’ and φ qis used. In Equation (3), Δ is attached to the term representing the difference between Equation (1) and Equation (2), and the difference in d-axis current and the difference in q-axis current are Δi d and Δi q are used, and the difference in d-axis magnetic flux and the difference in q-axis magnetic flux are Δφ d and Δφ q is used. Regarding the voltage difference between Equation (1) and Equation (2), it is set to 0 on the assumption that the voltage applied to the IPMSM does not change between the transient state and the steady state. i d ’ and i q ’ in Equation (2), and Δi d and Δi q in Equation (3) are also functions of time.

[0024] Regarding Equation (3), when solving for the current that is a function of time using the Laplace transform, Equation (4) can be derived. e included in Equation (4) is the Napier's number representing the exponential function.

[0025]

Equation

[0026] From Equation (4), the currents Δi d and Δi q at the time of PWM mode switching are sine waves and cosine waves proportional to the motor magnetic flux differences Δφ d and Δφ q of each axis before and after switching, and together with the exponential function term, they are damped oscillations. Also, the currents of the d-axis and q-axis are inversely proportional to the motor inductances L d and L q of each axis. Among the variables included in Equation (4), those that can be controlled by operation without changing the motor are only the motor magnetic flux differences Δφ d and Δφ q . Therefore, if the PWM mode switching is performed so that the motor magnetic flux differences Δφ d and Δφ q become small, current oscillation can be suppressed. Note that the frequency of the current oscillation is the angular frequency ω of the inverter, and the phase of the current oscillation is the motor magnetic flux difference Δφ d and Δφ qIt is obtained by the arctangent operation.

[0027] Here, the method for calculating the motor flux will be described. The linkage fluxes (motor fluxes) φ u φ v and φ w of each of the u-phase, v-phase, and w-phase can be calculated from the phase voltages v u , v v , v w of each of the three phases, the phase currents i u , i v , i w of each of the three phases, and the winding resistance R. The calculation formula for the motor flux is expressed by Equation (5).

[0028]

Equation

[0029] When the rotational speed of the rotating machine is at medium speed or higher, the second term on the right side of Equation (5) is small compared to the first term on the right side and can be ignored. Therefore, for the calculation of the motor flux, the integrated value of the voltage of each phase may be used. When applying a voltage from the inverter to the motor, since the voltage of the motor is the product of the PWM pulse applied to the gate of the semiconductor switching element constituting the inverter and 1 / 2 of the power supply voltage, the integrated value of the motor voltage of each phase and the integrated value of the PWM pulse applied to the gate have the same waveform shape. Therefore, it is possible to calculate the magnetic flux equivalent of the motor from the PWM pulse applied to the inverter.

[0030] To represent the motor flux in the rotating coordinate system, perform the three-phase to two-phase conversion shown in the following Equation (6), and further perform the rotational coordinate conversion as shown in Equation (7) using the position θ m of the motor poles.

[0031]

Equation

[0032]

Equation

[0033] According to the above formula (4), the motor flux difference Δφ before and after PWM mode switching d and Δφ q can be reduced to suppress the current oscillation during PWM mode switching. As shown in the following formula (8) for the term of the motor flux difference in formula (4), the flux evaluation function E f is defined as follows.

[0034]

Equation

[0035] The motor current when the flux evaluation function E f is reduced during PWM mode switching is shown in FIG. 12. FIG. 12 is a diagram showing a second example of the current oscillation generated when switching the PWM mode. Similar to FIG. 11, the first row from the top shows the d-axis current, the second row shows the oscillation of the d-axis current (the d-axis current after passing through the BPF), the third row shows the q-axis current, and the fourth row shows the oscillation of the q-axis current (the q-axis current after passing through the BPF). The vertical broken line in the center indicates the switching timing of the PWM mode. Note that the current oscillation shown in FIG. 12 corresponds to an example of the current oscillation when Embodiment 1 is applied. As shown in FIG. 12, by reducing the flux evaluation function E f defined by formula (8), the current oscillation during PWM mode switching can be suppressed compared to the case shown in FIG. 11.

[0036] Next, the characteristics of the flux evaluation function when performing PWM mode switching between synchronous PWMs, and the characteristics of the flux evaluation function when performing PWM mode switching from asynchronous PWM to synchronous PWM will be described.

[0037] FIG. 13 is a diagram showing an example of the carrier wave used in each of the two synchronous PWMs when performing PWM mode switching between synchronous PWMs. Each carrier wave is referred to as synchronous carrier wave #1 and #2. Further, FIG. 14 is a diagram showing the flux evaluation function E fss generated by the synchronous carrier wave #1 and the synchronous carrier wave #2 shown in FIG. 13.

[0038] Since the carrier wave of the synchronous PWM is synchronized with the u-phase voltage phase (hereinafter simply referred to as the voltage phase), the voltage applied to the IPMSM is synchronized with the voltage phase, and the motor flux represented by the integral of the voltage applied to the IPMSM is also synchronized with the voltage phase. Since the motor flux before and after the PWM mode switching is synchronized with the voltage phase, as a result, the flux evaluation function E fss is synchronized with the voltage phase as shown in FIG. 14. Also, when performing PWM mode switching between synchronous PWMs using the synchronous carrier waves #1 and #2 shown in FIG. 13, the flux evaluation function E fss is a waveform that repeats every 60 degrees as shown in FIG. 14. Therefore, in the switching between synchronous PWMs, it is easy to calculate in advance the phase at which the flux evaluation function E fss becomes minimum from the relationship between the carrier waves in each synchronous PWM.

[0039] FIG. 15 is a diagram showing an example of the carrier waves used in each of the two PWM modes (asynchronous PWM and synchronous PWM) when performing PWM mode switching from asynchronous PWM to synchronous PWM. The carrier wave used in asynchronous PWM is referred to as the asynchronous carrier wave, and the carrier wave used in synchronous PWM is referred to as the synchronous carrier wave. Also, FIG. 16 is a diagram showing the flux evaluation function E fas generated by the asynchronous carrier wave and the synchronous carrier wave shown in FIG. 15.

[0040] Since the carrier wave of the asynchronous PWM (corresponding to the asynchronous carrier wave shown in FIG. 15) is not synchronized with the voltage phase, the voltage applied to the IPMSM is not synchronized with the voltage phase, and the motor flux represented by the integral of the voltage applied to the IPMSM is also not synchronized with the voltage phase. Therefore, based on the motor flux when controlling the IPMSM with synchronous PWM and the motor flux when controlling the IPSMS with asynchronous PWM, the flux evaluation function E fas is calculated, and a flux evaluation function E fas that is not synchronized with the voltage phase is calculated. There is also no repeating waveform every 60 degrees as in the PWM mode switching between synchronous PWMs. Also, since the carrier wave of the asynchronous PWM is not synchronized with the voltage phase, depending on the phase of the carrier wave of the asynchronous PWM, the flux evaluation function E fasThe shape changes. Therefore, in the PWM mode switching from asynchronous PWM to synchronous PWM, the magnetic flux evaluation function E fas cannot identify the phase at which it becomes minimum. Note that since the magnetic flux difference is the same even in the PWM mode switching from synchronous PWM to asynchronous PWM, the phase at which the magnetic flux evaluation function becomes minimum cannot be identified. That is, in the PWM mode switching between asynchronous PWM and synchronous PWM, the phase at which the magnetic flux evaluation function becomes minimum cannot be identified.

[0041] Next, the rotary electric machine control device according to Embodiment 1 will be described. FIG. 1 is a diagram showing a configuration example of a rotary electric machine control device 1 according to Embodiment 1.

[0042] The rotary electric machine control device 1 includes a voltage applicator 3 and a controller 4. The voltage applicator 3 is connected to the rotary electric machine 2 and generates three-phase voltages V u , V v , V w to be applied to the rotary electric machine 2. The controller 4 is connected to the voltage applicator 3 and generates PWM pulses V ug , V vg , V wg as PWM signals for controlling the voltage generation operation by the voltage applicator 3 in the first PWM mode or the second PWM mode. In the present embodiment, the first PWM mode will be described as asynchronous PWM and the second PWM mode will be described as synchronous PWM.

[0043] The controller 4 includes a timing generator 5, a PWM mode selector 6, a modulation wave generator 7, a carrier selector 8, and a PWM pulse generator 9.

[0044] The timing generator 5 receives a first carrier cr u1 , cr v1 , cr w1 , a second carrier cr u2 , cr v2 , cr w2 , and an output voltage phase command θ. The output voltage phase command θ is the three-phase voltages V u , V v , V wIndicates the command value of the phase. The timing generator 5 is the first carrier wave cr u1 , cr v1 , cr w1 , the second carrier wave cr u2 , cr v2 , cr w2 And based on the output voltage phase command θ, it determines whether it is the switching timing of the PWM mode, and generates a timing signal Tr indicating that it is the switching timing of the PWM mode when it is determined to be the switching timing of the PWM mode.

[0045] The PWM mode selector 6 receives the fundamental wave frequency F of the voltage output by the voltage applicator 3 INV And the voltage command V for controlling the rotating machine 2 u * , V v * , V w * And the timing signal Tr output by the timing generator 5 are input. The PWM mode selector 6 is the fundamental wave frequency F INV , the voltage command V u * , V v * , V w * And based on the timing signal Tr, generates a PWM mode selection signal P mode .

[0046] The modulation wave generator 7 receives the voltage command V u * , V v * , V w * And the output voltage phase command θ, and the PWM mode selection signal P mode Are input. The modulation wave generator 7 is the voltage command V u * , V v * , V w * , the output voltage phase command θ and the PWM mode selection signal P mode Based on, generates a modulation wave v u * , v v * , vw * is generated.

[0047] The carrier wave selector 8 receives the first carrier wave cr u1 , cr v1 , cr w1 and the second carrier wave cr u2 , cr v2 , cr w2 and the PWM mode selection signal P mode . Based on the PWM mode selection signal P mode , the carrier wave selector 8 selects either the first carrier wave cr u1 , cr v1 , cr w1 or the second carrier wave cr u2 , cr v2 , cr w2 and outputs it as the carrier wave cr u , cr v , cr w .

[0048] The PWM pulse generator 9 receives the modulation wave v u * , v v * , v w * and the carrier wave cr u , cr v , cr w . Based on the modulation wave v u * , v v * , v w * and the carrier wave cr u , cr v , cr w , the PWM pulse generator 9 generates the PWM pulses V ug , V vg , V wg which are PWM signals for controlling the voltage applicator 3. In the following description, the PWM pulses generated by the PWM pulse generator 9 during the operation of asynchronous PWM may be referred to as asynchronous PWM pulses, and the PWM pulses generated by the PWM pulse generator 9 during the operation of synchronous PWM may be referred to as synchronous PWM pulses.

[0049] The PWM pulse V generated by the PWM pulse generator 9 ug , V vg , V wg is input to the voltage applicator 3, and the voltage applicator 3 generates a three-phase voltage V ug , V vg , V wg to be applied to the rotating machine 2 based on V u , V v , V w .

[0050] The rotating machine 2 is driven by the three-phase voltage V u , V v , V w output by the voltage applicator 3. The rotating machine 2 may be the above-described IPMSM, or may be an induction motor (IM) or a synchronous reluctance motor (SynRM).

[0051] The first carrier wave cr u1 , cr v1 , cr w1 input to the timing generator 5 and the carrier wave selector 8 is a carrier wave corresponding to the first PWM mode and is an asynchronous carrier wave that is not synchronized with the output voltage phase command θ. The second carrier wave cr u2 , cr v2 , cr w2 is a carrier wave corresponding to the second PWM mode and is a synchronous carrier wave that is synchronized with the output voltage phase command θ. Note that the first carrier wave cr u1 , cr v1 , cr w1 may be carrier waves of the same phase or carrier waves of different phases in three phases. The second carrier wave cr u2 , cr v2 , cr w2 may also be carrier waves of the same phase or carrier waves of different phases in three phases. The first carrier wave cr u1 , cr v1 , cr w1 and the second carrier wave cr u2 , cr v2 , cr w2is a signal without units, and its value changes between minus 1 and plus 1.

[0052] FIG. 2 is a diagram showing a configuration example of a timing generator 5 included in the rotation control device 1 according to Embodiment 1.

[0053] The timing generator 5 includes a first discriminator 50, a second discriminator 51, arithmetic units 52 to 54, and a logical product arithmetic unit 55.

[0054] The first discriminator 50 receives a first carrier wave cr u1 and a calculation result cr u1 of the sign of the slope of the first carrier wave cr st1 that has been calculated in advance and is stored in a memory. The calculation result cr st1 stored in the memory is a comparison value. The first discriminator 50 compares the sign of the slope of the input first carrier wave cr u1 with the comparison value cr st1 and outputs a value indicating true when they match, and outputs a value indicating false when they do not match. Specifically, the first discriminator 50 outputs '1' when the sign of the slope of the first carrier wave cr u1 matches the comparison value cr st1 , and outputs '0' when they do not match.

[0055] The second discriminator 51 receives a second carrier wave cr u2 and a calculation result cr u2 of the sign of the slope of the second carrier wave cr st2 that has been calculated in advance and is stored in a memory. The calculation result cr st2 stored in the memory is a comparison value. The second discriminator 51 compares the sign of the slope of the input second carrier wave cr u2 with the comparison value cr st2 and outputs a value indicating true when they match, and outputs a value indicating false when they do not match. Specifically, the second discriminator 51 outputs '1' when the sign of the slope of the second carrier wave cr u2 matches the comparison value cr st2Output '1' if they match, and output '0' if they do not match.

[0056] The arithmetic unit 52 receives the first carrier wave cr u1 and the calculation result cr u1 of the first carrier wave cr nt1 which has been calculated in advance and stored in the memory. The calculation result cr nt1 stored in the memory is the comparison value. The arithmetic unit 52 calculates the carrier wave instantaneous value difference Δcr1 between the input instantaneous value of the first carrier wave cr u1 and the comparison value cr nt1 outputs a value indicating true when the carrier wave instantaneous value difference Δcr1 is 0 or within the allowable range of deviation, and outputs a value indicating false when the carrier wave instantaneous value difference Δcr1 is not within the allowable range of deviation. Specifically, the arithmetic unit 52 outputs '1' as a value indicating true when the carrier wave instantaneous value difference Δcr1 is less than a predetermined threshold value, and outputs '0' as a value indicating false when it is greater than or equal to the threshold value.

[0057] The arithmetic unit 53 receives the second carrier wave cr u2 and the calculation result cr u2 of the second carrier wave cr nt2 which has been calculated in advance and stored in the memory. The calculation result cr nt2 stored in the memory is the comparison value. The arithmetic unit 53 calculates the carrier wave instantaneous value difference Δcr2 between the input instantaneous value of the second carrier wave cr u2 and the comparison value cr nt2 outputs a value indicating true when the carrier wave instantaneous value difference Δcr2 is 0 or within the allowable range of deviation, and outputs a value indicating false when the carrier wave instantaneous value difference Δcr2 is not within the allowable range of deviation. Specifically, the arithmetic unit 53 outputs '1' as a value indicating true when the carrier wave instantaneous value difference Δcr2 is less than a predetermined threshold value, and outputs '0' as a value indicating false when it is greater than or equal to the threshold value.

[0058] The arithmetic unit 54 receives the output voltage phase command θ and the calculation result θ t of the output voltage phase command θ which has been calculated in advance and stored in the memory. The calculation result θ tis a comparison value. The arithmetic unit 54 calculates the phase difference Δθ between the input output voltage phase command θ and the comparison value θ t and outputs a value indicating true when the phase difference Δθ is 0 or within the allowable range of deviation, and outputs a value indicating false when the phase difference Δθ is not within the allowable range of deviation. Specifically, when the phase difference Δθ is less than a predetermined threshold value, the arithmetic unit 54 outputs '1' as a value indicating true, and when it is equal to or greater than the threshold value, it outputs '0' as a value indicating false.

[0059] Signals output by the first determination unit 50, the second determination unit 51, and the arithmetic units 52 to 54 are input to the logical product arithmetic unit 55. When all the input signals are values indicating true, that is, '1', the logical product arithmetic unit 55 outputs a value indicating true as the timing signal Tr, and when there is a value indicating false among the input signals, it outputs a value indicating false as the timing signal Tr. Specifically, when all the input signals are values indicating true, the logical product arithmetic unit 55 outputs '1' as the timing signal Tr, and when there is a value indicating false among the input signals, it outputs '0' as the timing signal Tr.

[0060] Note that each of the above-mentioned comparison values calculated in advance, that is, cr st1 、cr st2 、cr nt1 、cr nt2 and θ t may be held inside the timing generator 5 or may be held by external storage means.

[0061] Also, in this embodiment, the timing generator 5 generates the first carrier wave cr of the u phase u1 and the second carrier wave cr u2Based on the output voltage phase command θ, it determines whether it is the switching timing of the PWM mode. An example of changing the state of the timing signal Tr when determining the switching timing of the PWM mode has been described. However, the switching timing of the PWM mode may be determined based on the first carrier wave and the second carrier wave of the v-phase and the output voltage phase command θ, or it may be determined based on the first carrier wave and the second carrier wave of the w-phase and the output voltage phase command θ.

[0062] The PWM mode selector 6 selects the PWM mode selection signal P INV for the fundamental wave frequency F of the voltage output by the voltage applicator 3 u * , V v * , V w * to select the first PWM mode or the second PWM mode, and outputs it to the modulation wave generator 7 and the carrier wave selector 8. The PWM mode selector 6 switches the value of the PWM mode selection signal P mode at the timing when the logic of the timing signal Tr input from the timing generator 5 changes from false to true. mode

[0063] The modulation waves v u * , v v * , v w * are respectively sine waves of the three phases of the u-phase, v-phase, and w-phase. A phase difference of 120 degrees is provided between the modulation waves v u * , v v * , v w * . The amplitudes of the modulation waves v u * , v v * , v w * are the voltage commands V input to the modulation wave generator 7 u * , V v *,V w * is determined by. Voltage command V u * ,V v * ,V w * has a magnitude of 0 to 4 / π, with the fundamental wave amplitude 4 / π obtained when the square wave is expanded into a Fourier series as the maximum value.

[0064] Modulating wave v u * ,v v * ,v w * For improving the utilization rate of the voltage output from the voltage applicator 3, a third harmonic wave with a frequency three times that of the modulating wave may be superimposed on the modulating wave. Voltage command V u * ,V v * ,V w * When the magnitude of exceeds 1 and drives the rotary machine 2, the voltage v u ,v v ,v w the fundamental wave voltage obtained by expanding into a Fourier series and the voltage command V u * ,V v * ,V w * may be multiplied by a gain for correcting the relationship with. The modulating wave corresponding to the asynchronous PWM pulse and the modulating wave corresponding to the synchronous PWM pulse may have different third harmonic waves and correction gains respectively. Therefore, the modulating wave generator 7 switches between the modulating wave corresponding to the asynchronous PWM pulse and the modulating wave corresponding to the synchronous PWM pulse according to the PWM mode selection signal P mode and outputs it as the modulating wave v u * ,v v * ,v w * .

[0065] The carrier wave selector 8 selects, according to the PWM mode selection signal P mode a first carrier wave cr corresponding to the asynchronous PWM pulseu1 , cr v1 , cr w1 and a second carrier wave cr corresponding to the synchronous PWM pulse u2 , cr v2 , cr w2 select either one of them as the carrier wave cr u , cr v , cr w and output it.

[0066] The PWM pulse generator 9 compares the modulation wave v input from the modulation wave generator 7 u * , v v * , v w * and the carrier wave cr input from the carrier wave selector 8 u , cr v , cr w in terms of magnitude for each of the u-phase, v-phase, and w-phase. For the u-phase, when the modulation wave v u * is greater than the carrier wave cr u , it outputs true, that is, '1', and when the modulation wave v u * is less than or equal to the carrier wave cr u , it outputs false, that is, '0', as the PWM pulse v ug to the voltage applicator 3. Similarly for the v-phase and w-phase, the modulation wave and the carrier wave of each phase are compared in terms of magnitude, and a value ('1' or '0') corresponding to the comparison result is output as the PWM pulse v vg , v wg to the voltage applicator 3.

[0067] The voltage applicator 3 has, for example, the configuration shown in FIG. 3. FIG. 3 is a diagram showing a configuration example of the voltage applicator 3 provided in the rotary machine control device 1 according to Embodiment 1, and shows a circuit configuration example when the voltage applicator 3 is a three-phase PWM inverter.

[0068] The voltage applicator 3 includes a leg 30A in which the semiconductor element UP in the upper arm and the semiconductor element UN in the lower arm are connected in series, a leg 30B in which the semiconductor element VP in the upper arm and the semiconductor element VN in the lower arm are connected in series, and a leg 30C in which the semiconductor element WP in the upper arm and the semiconductor element WN in the lower arm are connected in series.

[0069] The legs 30A to 30C are connected in parallel with each other, and a bus voltage is applied to the legs 30A to 30C through the DC buses 35a and 35b. The voltage applicator 3 converts the DC power of the power source 36 supplied to the legs 30A to 30C through the DC buses 35a and 35b into AC power, and drives the rotary machine 2 by supplying the converted AC power to the rotary machine 2.

[0070] In FIG. 3, the case where the semiconductor elements UP, UN, VP, VN, WP, and WN are metal-oxide-semiconductor field-effect transistors (MOSFETs) is illustrated. The semiconductor element UP includes a transistor 30a and a diode 30b connected in anti-parallel to the transistor 30a. The other semiconductor elements UN, VP, VN, WP, and WN have the same configuration. Anti-parallel means that the anode side of the diode 30b is connected to the first terminal corresponding to the source of the MOSFET, and the cathode side of the diode 30b is connected to the second terminal corresponding to the drain of the MOSFET.

[0071] Note that, instead of MOSFETs, insulated gate bipolar transistors (IGBTs), for example, may be used for the semiconductor elements UP, UN, VP, VN, WP, and WN.

[0072] The connection point 32 between the semiconductor element UP on the upper arm and the semiconductor element UN on the lower arm of the leg 30A is connected to the first phase (for example, the u-phase) of the rotating machine 2, the connection point 33 between the semiconductor element VP on the upper arm and the semiconductor element VN on the lower arm of the leg 30B is connected to the second phase (for example, the v-phase) of the rotating machine 2, and the connection point 34 between the semiconductor element WP on the upper arm and the semiconductor element WN on the lower arm of the leg 30C is connected to the third phase (for example, the w-phase) of the rotating machine 2. In the voltage applicator 3, the connection points 32, 33, and 34 form AC terminals.

[0073] Here, the voltage vector output by the voltage applicator 3 will be described. The voltage applicator 3 is a three-phase PWM inverter as described above, and is a power converter that obtains a desired voltage by performing PWM control on the DC power of the voltage V DC supplied from the power source 36 through the DC buses 35a and 35b. In the three-phase PWM inverter, there are two semiconductor switching elements, one above and one below, for each phase, and the upper and lower semiconductor switching elements operate so that one of them is in the on state. Therefore, in the three-phase PWM inverter, there are 2 to the 3rd power ( = 8 ways) of switching states.

[0074] Next, the comparison values cr st1 , cr st2 , cr nt1 , cr nt2 and θ t used in the timing generator 5 shown in FIG. 2 will be described.

[0075] When the asynchronous carrier wave and the synchronous carrier wave assuming PWM mode switching during the operation of the rotating machine 2 are in the relationship shown in, for example, FIG. 15, in advance, the three-phase asynchronous PWM pulses obtained by comparing the modulation wave corresponding to the asynchronous PWM with the asynchronous carrier wave outside the rotating machine control device 1, and the three-phase synchronous PWM pulses obtained by comparing the modulation wave corresponding to the synchronous PWM with the synchronous carrier wave are respectively integrated, and by performing the operations of the above-mentioned formulas (6), (7), and (8), the flux evaluation function E fas shown in FIG. 16 is calculated in advance.

[0076] As described first in this embodiment, the phase at which the value of the flux evaluation function E shown on the vertical axis of FIG. 16 is the smallest is the phase at which the amplitude of the current oscillation is the smallest. In FIG. 16, the u-phase voltage phase of 223 degrees is the phase at which the amplitude of the current oscillation is the smallest. Therefore, from FIG. 15, if the signs and instantaneous values of the slopes of the asynchronous carrier wave and the synchronous carrier wave at the u-phase voltage phase of 223 degrees are extracted and used, the current oscillation at the time of PWM mode switching can be suppressed without calculating the motor flux during the operation of the rotating machine 2. That is, the signs and instantaneous values of the slopes of the asynchronous carrier wave and the synchronous carrier wave when the flux evaluation function E fas becomes the minimum, which can be specified from the relationship between the asynchronous carrier wave and the synchronous carrier wave, are calculated in advance, and these are used as the comparison values cr fas described above. st1 cr st2 cr nt1 cr nt2 cr fas Let the u-phase voltage phase when the flux evaluation function E t becomes the minimum be the comparison value θ st1 described above. In this way, the comparison values cr st2 cr nt1 cr nt2 cr t and θ

[0077] required when the timing generator 5 generates the timing signal Tr can be calculated in advance. u * v v * v w * Since the three-phase PWM pulses are generated by comparing with the carrier waves cr u cr v cr w , the average value over one period may not be 0 like a sine wave. When integration is performed in a state where the average value over one period of the three-phase PWM pulses is not 0, the integral value diverges positively or negatively according to the sign of the average value over one period of the three-phase PWM pulses. Therefore, the integral value of the three-phase PWM pulses may be calculated by subtracting the average value over one period of the PWM pulses corresponding to each phase from the three-phase PWM pulses.

[0078] The above comparison value cr st1 , cr st2 , cr nt1 , cr nt2 and θ t are stored in the storage unit 58 and output from the storage unit 58 when the timing generator 5 generates the timing signal Tr. FIG. 4 is a diagram showing an example of the storage unit 58 that stores the comparison values used in the generation process of the timing signal Tr by the timing generator 5 according to the first embodiment. The storage unit 58 may be provided inside the timing generator 5 or outside the timing generator 5.

[0079] The above comparison value cr st1 , cr st2 , cr nt1 , cr nt2 and θ t may be fixed values or variables stored in a table whose output changes according to input conditions. The comparison value cr st1 , cr st2 , cr nt1 , cr nt2 and θ t FIG. 5 shows a configuration example of the storage unit 58 when they are variables. FIG. 5 is a diagram showing another example of the storage unit 58 that stores the comparison values used in the generation process of the timing signal Tr by the timing generator 5 according to the first embodiment. The storage unit 58 shown in FIG. 5 includes a table 59. The table 59 shown in FIG. 5 takes as inputs the number of asynchronous carrier cycles F AS included in one cycle of the output voltage phase command θ, the number of synchronous carrier cycles F SY included in one cycle of the output voltage phase command θ, and the voltage commands V u * , V v * and V w * and linearly searches for and outputs the pre-calculated and held comparison values cr st1 , cr st2 , cr nt1 , cr nt2 and θ t .

[0080] As described above, the rotary machine control device 1 according to the present embodiment is configured to be able to control the rotary machine 2 by appropriately using either one of two PWM modes, asynchronous PWM and synchronous PWM, and detects a timing at which current oscillation is suppressed when switching the PWM mode to be used, and includes a timing generator 5 that generates a signal indicating that timing. The timing generator 5 detects the switching timing of the PWM mode based on a first carrier wave used for PWM pulse generation in asynchronous PWM, a second carrier wave used for PWM pulse generation in synchronous PWM, and an output voltage phase command, and changes the state of the output timing signal to indicate that it is the switching timing of the PWM mode. Specifically, the timing generator 5 determines that the difference between the integrated value of the asynchronous PWM pulses and the integrated value of the synchronous PWM pulses is smaller than a predetermined value, and the first carrier wave cr u1 , cr v1 , cr w1 and the second carrier wave cr u2 , cr v2 , cr w2 and the timing at which the relationship is established is detected based on the first carrier wave cr u1 , the second carrier wave cr u2 and the output voltage phase command θ, and the comparison values cr st1 , cr st2 , cr nt1 , cr nt2 , cr t and θ that have been calculated in advance, and the state of the output timing signal is changed. When the state of the timing signal output by the timing generator 5 changes, the controller 4 of the rotary machine control device 1 switches the PWM mode used for controlling the rotary machine 2. As a result, the PWM mode can be switched at a timing when the difference between the magnetic flux of the rotary machine 2 in asynchronous PWM and the magnetic flux of the rotary machine 2 in synchronous PWM becomes small, and current oscillation at the time of PWM mode switching can be suppressed.

[0081] Embodiment 2. Next, Embodiment 2 will be described. For convenience of explanation, the rotation control device according to Embodiment 2 is referred to as rotation control device 1a to distinguish it from the rotation control device 1 according to Embodiment 1. The rotation control device 1a according to the present embodiment has a configuration in which the timing generator 5 (see FIGS. 1 and 2) of the rotation control device 1 according to Embodiment 1 is replaced with the timing generator 5a shown in FIG. 6. Since the components other than the timing generator 5a are the same as those in Embodiment 1, the description thereof is omitted. Note that FIG. 6 is a diagram showing a configuration example of the timing generator 5a included in the rotation control device 1a according to Embodiment 2.

[0082] The timing generator 5a includes arithmetic units 52 to 54, an AND arithmetic unit 55a, a phase holder 56, and an arithmetic unit 57. Since the arithmetic units 52 to 54 of the timing generator 5a according to the first embodiment are the same as the arithmetic units 52 to 54 of the timing generator 5 according to the first embodiment, the description thereof is omitted. In the present embodiment, θ is input to the arithmetic unit 54 as a calculation result of the output voltage phase command θ. t1 is input to the arithmetic unit 54.

[0083] Signals output from the arithmetic units 52 to 54 are input to the AND arithmetic unit 55a. The AND arithmetic unit 55a outputs a value indicating true, that is, '1', as a timing signal Tr' when all the input signals indicate true, that is, '1', and outputs a value indicating false as a timing signal Tr' when the input signals include a value indicating false. Specifically, the AND arithmetic unit 55a outputs '1' as the timing signal Tr' when all the input signals indicate true, and outputs '0' as the timing signal Tr' when the input signals include a value indicating false.

[0084] The timing signal Tr' output from the AND arithmetic unit 55a and the output voltage phase command θ are input to the phase holder 56. The phase holder 56 holds the phase of the output voltage phase command θ at the timing when the timing signal Tr' changes from false to true, and outputs the held phase as a reference phase θ. That is, the phase holder 56 sets the value of the output voltage phase command θ when the timing signal Tr' changes from false to true as the reference phase θ. b and outputs it. bContinue to output as such.

[0085] The arithmetic unit 57 receives the reference phase θ output by the phase retainer 56 b and the delay phase θ that has been calculated in advance and is stored in the memory. t2 The arithmetic unit 57 calculates the phase difference between the input reference phase θ b and the delay phase θ t2 If the calculated phase difference is 0 or within the allowable deviation range, it outputs a value indicating true as the timing signal Tr. If the calculated phase difference is not within the allowable deviation range, it outputs a value indicating false as the timing signal Tr. Specifically, when the calculated phase difference is less than a predetermined threshold, the arithmetic unit 57 outputs '1' as the timing signal Tr, and when it is equal to or greater than the threshold, it outputs '0' as the timing signal Tr.

[0086] In the timing generator 5a according to Embodiment 2 shown in FIG. 6, when the asynchronous carrier wave and the synchronous carrier wave respectively reach the apex (maximum value or minimum value) of minus 1 or plus 1 at a specific phase, that phase is set as the reference phase θ b and the timing signal Tr is output at a phase obtained by delaying the reference phase θ b by a certain phase.

[0087] The arithmetic units 52 and 53 respectively detect the apexes of the carrier waves cr u1 , cr u2 Since the apex of the carrier wave has a slope of 0, it is not necessary to determine the sign of the slope. Therefore, the comparison value cr u1 of the first carrier wave cr nt1 calculated in advance and the comparison value cr u2 of the second carrier wave cr nt2 calculated in advance are set to minus 1 or plus 1. Also, the comparison value θ t1 of the output voltage phase command θ calculated in advance is set to the phase at which the synchronous carrier wave reaches the apex. For example, in the example shown in FIG. 15 used above, since the asynchronous carrier wave and the synchronous carrier wave respectively become minus 1 at 150 degrees, the reference phase θ b can be set to 150 degrees.

[0088] The delay phase θ to be calculated in advance t2 will be described. Consider the case where the first carrier wave cr u1 and the second carrier wave cr u2 input to the timing generator 5a are the asynchronous carrier wave and the synchronous carrier wave in the example shown in FIG. 15. In this case, the flux evaluation function E fas generated by the asynchronous carrier wave and the synchronous carrier wave is as shown in FIG. 16, and the phase at which the flux evaluation function E fas is minimized is 223 degrees. Therefore, when the reference phase θ b is set to 150 degrees, 223 degrees is set as the delay phase θ t2 . According to this setting, the timing generator 5a outputs a timing signal Tr, and the PWM mode selector 6 switches the PWM mode at the timing according to this timing signal Tr, thereby suppressing current oscillation at the time of PWM mode switching.

[0089] Note that the comparison values cr nt1 , cr nt2 , θ t1 and the delay phase θ t2 are stored in the storage unit 60 as shown in FIG. 7 and are output from the storage unit 60 when the timing generator 5a generates the timing signal Tr. FIG. 7 is a diagram showing an example of a storage unit 60 that stores comparison values and delay phases used in the generation process of the timing signal Tr by the timing generator 5a according to the second embodiment. The storage unit 60 may be provided inside the timing generator 5a or may be provided outside the timing generator 5a.

[0090] The above comparison values cr nt1 , cr nt2 , θ t1 and the delay phase θ t2 may be fixed values or variables stored in a table whose output changes according to input conditions. The comparison values cr nt1 , cr nt2 , θ t1 and the delay phase θ t2Fig. 8 shows a configuration example of the storage unit 60 when [a certain element] is used as a variable. Fig. 8 is a diagram showing another example of the storage unit 60 that stores the comparison values and delay phases used in the generation process of the timing signal Tr by the timing generator 5a according to the second embodiment. The storage unit 60 in the other example shown in Fig. 8 includes a table 61. The table 61 shown in Fig. 8 takes as inputs the number of cycles F of the asynchronous carrier wave included in one cycle of the output voltage phase command θ AS and the number of cycles F of the synchronous carrier wave included in one cycle of the output voltage phase command θ SY and the voltage commands V u * , V v * and V w * and linearly searches for and outputs the pre-calculated and held comparison values cr nt1 , cr nt2 , θ t1 and the delay phase θ t2 .

[0091] The storage unit 60 may have the configuration shown in Fig. 9 or Fig. 10. Fig. 9 is a diagram showing a modified example of the storage unit 60 shown in Fig. 7, and Fig. 10 is a diagram showing a modified example of the storage unit 60 shown in Fig. 8.

[0092] The configurations shown in Fig. 9 and Fig. 10 are different in that part of the information stored in the storage unit 60 is different from the information stored in the storage units 60 shown in Fig. 7 and Fig. 8, and also in that arithmetic units 62 and 63 are provided at the subsequent stage of the storage unit 60. As described above, the storage units 60 shown in Fig. 7 and Fig. 8 store the comparison values cr nt1 , cr nt2 , θ t1 and the delay phase θ t2 , while the storage units 60 shown in Fig. 9 and Fig. 10 store the comparison values cr nt1 , cr nt2 , θ t1 and the delay phase θ t2 '. That is, the storage units 60 shown in Fig. 9 and Fig. 10 store the delay phase θ t2 ' instead of the delay phase θ t2 stored in the storage units 60 shown in Fig. 7 and Fig. 8.

[0093] In the configuration shown in FIGS. 9 and 10, the arithmetic unit 62 calculates the phase difference Δθ between the output voltage phase command θ and the comparison value θ held by the storage unit 60. Further, the arithmetic unit 63 adds the phase difference Δθ output by the arithmetic unit 62 and the delay phase θ' held by the storage unit 60, and outputs the result of this addition operation as the corrected delay phase θ. When the phase difference Δθ is not zero, since the reference phase θ is displaced with respect to the peak of the synchronous carrier wave, the phase at which the magnetic flux evaluation function E becomes the minimum value is also displaced. Therefore, the arithmetic unit 63 adds the phase difference Δθ to the delay phase θ' to correct the delay phase θ', and obtains the corrected delay phase θ. t1 The rotation control device 1a to which the timing generator 5a described in this embodiment is applied can switch the PWM mode at the same timing as the rotation control device 1 according to Embodiment 1, and can suppress current oscillation during PWM mode switching. t2 The configurations shown in the above embodiments are merely examples, and it is possible to combine them with other known techniques, combine the embodiments with each other, and omit or change a part of the configuration without departing from the gist. t2

Explanation of Reference Numerals

Explanation of Reference Numerals

[0094] The rotation control device 1a to which the timing generator 5a described in this embodiment is applied can switch the PWM mode at the same timing as the rotation control device 1 according to Embodiment 1, and can suppress current oscillation during PWM mode switching.

[0095] The configurations shown in the above embodiments are merely examples, and it is possible to combine them with other known techniques, combine the embodiments with each other, and omit or change a part of the configuration without departing from the gist.

Explanation of Reference Numerals

[0096] 1 Rotation control device, 2 Rotating machine, 3 Voltage applicator, 4 Controller, 5, 5a Timing generator, 6 PWM mode selector, 7 Modulation wave generator, 8 Carrier wave selector, 9 PWM pulse generator, 30A, 30B, 30C Legs, 30a Transistor, 30b Diode, 32, 33, 34 Connection points, 35a, 35b DC bus, 36 Power source, 50 First determiner, 51 Second determiner, 52, 53, 54, 57, 62, 63 Arithmetic units, 55, 55a Logical product arithmetic units, 56 Phase holder, 58, 60 Storage units, 59, 61 Tables.

Claims

1. A voltage applicator that generates a three-phase voltage to be applied to a rotating machine, A controller that controls the voltage generation operation by the voltage applicator in a first pulse width modulation mode in which the carrier frequency is not synchronized with the frequency of the voltage command or in a second pulse width modulation mode in which the carrier frequency is synchronized with the frequency of the voltage command, Comprising, The controller, Based on a first carrier wave used for generating a signal for controlling the voltage applicator in the first pulse width modulation mode, a second carrier wave used for generating a signal for controlling the voltage applicator in the second pulse width modulation mode, and an output voltage phase command for commanding the phase of the output voltage to the rotating machine, selects either the first pulse width modulation mode or the second pulse width modulation mode as the pulse width modulation method used for controlling the voltage generation operation, and When switching the pulse width modulation method used for controlling the voltage generation operation, based on the first carrier wave, the second carrier wave, and the output voltage phase command, detects the timing at which the difference between the linkage magnetic flux of the rotating machine when the voltage generation operation is controlled in the first pulse width modulation mode and the linkage magnetic flux of the rotating machine when the voltage generation operation is controlled in the second pulse width modulation mode is minimized, and sets the detected timing as the switching timing of the pulse width modulation method, A rotating machine control device characterized by this.

2. The controller, A timing generator that determines the switching timing of the pulse width modulation method used for controlling the voltage generation operation based on the first carrier wave, the second carrier wave, and the output voltage phase command, A pulse width modulation mode selector that selects either the first pulse width modulation mode or the second pulse width modulation mode as the pulse width modulation method used for controlling the voltage generation operation when the timing generator determines that it is the switching timing of the pulse width modulation mode, The rotating machine control device according to claim 1, characterized by comprising.

3. A storage unit that holds the sign of the slope of the first carrier wave, the sign of the slope of the second carrier wave, the instantaneous value of the first carrier wave, the instantaneous value of the second carrier wave, and the phase of the output voltage to the rotating machine when the difference between the interlinkage magnetic flux of the rotating machine when controlling the voltage generation operation in the first pulse width modulation mode and the interlinkage magnetic flux of the rotating machine when controlling the voltage generation operation in the second pulse width modulation mode is minimized. The timing generator determines that it is the switching timing of the pulse width modulation method when the sign of the slope of the first carrier wave and the sign of the slope of the second carrier wave respectively match the sign of the slope of the first carrier wave and the sign of the slope of the second carrier wave held by the storage unit, and the difference between each of the instantaneous value of the first carrier wave and the instantaneous value of the second carrier wave and each of the instantaneous value of the first carrier wave and the instantaneous value of the second carrier wave held by the storage unit is less than a determined threshold value, and the difference between the value of the output voltage phase command and the phase of the output voltage to the rotating machine held by the storage unit is less than a determined threshold value. The rotating machine control device according to claim 2, characterized in that.

4. The storage unit is provided with a table that takes as inputs the frequency of the first carrier wave, the frequency of the second carrier wave, and the voltage command, and linearly searches and outputs the sign of the slope of the first carrier wave, the sign of the slope of the second carrier wave, the instantaneous value of the first carrier wave, the instantaneous value of the second carrier wave, and the phase of the output voltage to the rotating machine that it holds. The rotating machine control device according to claim 3, characterized in that.

5. A storage unit that holds the instantaneous value of the first carrier wave, the instantaneous value of the second carrier wave, the phase of the output voltage to the rotating machine, and the delay phase derived from the relationship between the first carrier wave and the second carrier wave when the difference between the interlinkage magnetic flux of the rotating machine when controlling the voltage generation operation in the first pulse width modulation mode and the interlinkage magnetic flux of the rotating machine when controlling the voltage generation operation in the second pulse width modulation mode is minimized. The timing generator When the difference between the instantaneous value of the first carrier wave and the instantaneous value of the second carrier wave, respectively, and the instantaneous value of the first carrier wave and the instantaneous value of the second carrier wave held by the storage unit is less than a determined threshold value, and the difference between the value of the output voltage phase command and the phase of the output voltage to the rotating machine held by the storage unit is less than a determined threshold value, the value of the output voltage phase command at this point in time is set as the reference phase. When the difference between the reference phase and the delay phase held by the storage unit is less than a determined threshold value, it is determined that this is the switching timing of the pulse width modulation method. The rotating machine control device according to claim 2, characterized in that.

6. The storage unit receives as inputs the frequency of the first carrier wave, the frequency of the second carrier wave, and the voltage command, and includes a table that linearly searches and outputs the instantaneous value of the first carrier wave, the instantaneous value of the second carrier wave, the phase of the output voltage to the rotating machine, and the delay phase that it holds. The rotating machine control device according to claim 5, characterized in that.

7. Calculate the phase difference between the value of the output voltage phase command and the phase of the output voltage to the rotating machine output from the storage unit, add the calculated phase difference to the delay phase output from the storage unit to correct the delay phase, and use the corrected delay phase for the timing generator to determine the switching timing. The rotating machine control device according to claim 5 or 6, characterized in that.

Images