JP2017112647A - Control apparatus of rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control apparatus of a rotary machine, which properly suppresses a power fluctuation at switching of a pulse pattern.SOLUTION: A motor control apparatus 101 outputs a gate signal based on a pulse pattern which regulates an ON/OFF state in accordance to a rotor position of a motor 80 to an inverter 60, and controls an electric conduction of the motor 80. The motor control apparatus 101 comprises: a modulation factor calculation part 15 that calculates a modulation factor M on the basis of a power supply voltage Vin and a voltage amplitude Vamp; and a pulse pattern setting part 20 that sets a pulse pattern PP in accordance with the modulation factor M calculated by the modulation factor calculation part 15. The pulse pattern setting part 20 set a range of the rotor position continuing an output voltage of the pulse pattern of at least any one of phases in the ON or OFF state as a switching permission range. When the modulation factor M is changed, the pulse pattern is changed in a switching permission range. Thus, the generation of voltage change at the switching is avoided, a voltage fluctuation or a torque fluctuation can be suppressed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a control device that controls energization of an AC rotating machine.

  Conventionally, in the control of a rotating machine, an output voltage pattern (hereinafter referred to as “pulse pattern”) having an optimal pulse waveform synchronized with the rotor position (ie, electrical angle) of the rotating machine is set based on the modulation rate, Techniques for operating a plurality of switching elements of a power converter with a gate signal based thereon are known.

  In addition, the power conversion device disclosed in Patent Document 1 uses a switching pattern in which a minimum pulse width determined by the characteristics of a switching element in PWM control is ensured according to the magnitude of the modulation rate for each number of pulses. When the number of pulses changes and the switching pattern is switched, a switching transition period for suppressing voltage fluctuation is provided, and a dummy pulse is generated so as to ensure the minimum pulse width in the switching transition period. As a result, current fluctuations and torque fluctuations when switching the number of pulses are reduced.

JP 2014-143831 A

In the prior art of Patent Document 1, it is necessary to generate an extra pattern for generating a dummy pulse, which increases the memory load. In addition, voltage fluctuation may occur even when the number of pulses is the same, but nothing is mentioned about this point.
The present invention was created in view of the above points, and an object of the present invention is to provide a control device for a rotating machine that appropriately suppresses power fluctuations at the time of switching pulse patterns.

The present invention turns ON / OFF a plurality of switching elements (61 to 66) of a power converter (60) for supplying power to a multiphase rotating machine (80) having three or more phases according to the rotor position of the rotating machine. The invention relates to a control device for a rotating machine that outputs a gate signal based on a pulse pattern that defines a state and controls energization of the rotating machine.
The control device of the rotating machine includes a modulation factor calculation unit (15) and a pulse pattern setting unit (20). The modulation factor calculator calculates the modulation factor based on the power supply voltage and the voltage amplitude. The pulse pattern setting unit sets a pulse pattern according to the modulation rate calculated by the modulation rate calculation unit.

  The pulse pattern setting unit sets the range of the rotor position where the output voltage of the pulse pattern of at least one of the phases, preferably all of the phases continues in the ON state or OFF state, as the “switching permission range”, and the modulation rate When is changed, the pulse pattern is switched within the switching permission range.

  For example, when the pulse pattern is switched at the rotor position where the output voltage before switching is in the ON state and the output voltage after switching is in the OFF state, the voltage changes before and after switching, and an unintended pulse is output. There is a risk of fluctuations and torque fluctuations of the rotating machine. Therefore, by switching the pulse pattern within the switching permission range where the output voltage does not change, it is possible to avoid the occurrence of voltage change and suppress power fluctuation and torque fluctuation.

Preferably, the pulse pattern setting unit determines the current fundamental wave voltage based on a ratio between the current and next fundamental wave voltage amplitudes for the fundamental wave voltage corresponding to the modulation rate calculated at a predetermined calculation period in the modulation rate calculation unit. The rotor position where the value and the next fundamental wave voltage value match is calculated as the “ideal switching position”.
When the ideal switching position is within the switching permission range, the pulse pattern is switched at the ideal switching position. Thereby, the fundamental voltage value can be continuously changed at the time of switching.
On the other hand, when the ideal switching position is outside the switching permission range, the pulse pattern is switched at “the switching position corrected to the rotor position closest to the ideal switching position within the switching permission range”.
Thereby, the fundamental voltage value can be continuously changed at the time of switching.

  By the way, the positions of 0 and 180 [deg] that are theoretically ideal switching positions when the phase shift of the current and next fundamental voltage is set to 0 or 180 [deg] are basically pulse edges. In addition, since relatively narrow pulses are concentrated in the vicinity of 0 and 180 [deg], it is difficult to ensure a switching permission range. Therefore, the ideal switching position is preferably set to a position where the phase shift is other than 0 and 180 [deg], for example, near 90 or 270 [deg].

  The switching permission range is preferably set according to the number of rotations of the rotating machine in addition to the combination of the modulation rates before and after the change. Further, it is preferable that the position range corresponding to the dead time is avoided and the period is equal to or longer than the calculation period of the voltage command.

1 is an overall configuration diagram of a vehicle drive motor control system to which a control device for a rotating machine according to each embodiment of the present invention is applied. The control block diagram which shows the structure of the control apparatus of the rotary machine by 1st Embodiment. The detailed block diagram of a pulse pattern setting part. The figure explaining the symmetry of a pulse pattern. The figure which shows the example of the pulse pattern according to a modulation rate. The figure which shows the example of the pulse pattern according to a modulation rate. The figure explaining the continuity of the fundamental wave voltage value at the time of pulse pattern switching. The figure explaining the setting of an ideal switching position. The figure explaining generation | occurrence | production of the voltage change at the time of pulse pattern switching. The figure explaining the setting of a switching permission range. The figure explaining the setting of the switch permission range in a three-phase alternating voltage. The figure explaining the setting of the switch permission range at the time of (a) rotation speed N and (b) 3N. The figure explaining the setting of the switch permission range with respect to a calculation period. The figure explaining the setting of the switching permission range which avoids dead time. The main flowchart of the inverter drive process by 1st Embodiment. FIG. 16 is a sub-flowchart of “switching position / pulse pattern setting process” in FIG. 15; The figure which shows the sharp change of the rotation rate or the modulation rate which is a subject of 2nd Embodiment. The main flowchart of the inverter drive process by 2nd Embodiment. The control block diagram which shows the structure of the control apparatus of the rotary machine by 3rd Embodiment.

Hereinafter, a control device for a rotating machine according to an embodiment of the present invention will be described with reference to the drawings. In the plurality of embodiments, substantially the same configuration is denoted by the same reference numeral, and description thereof is omitted.
This control device for a rotating machine is applied to a drive system for a main motor that is a power source of a hybrid vehicle or an electric vehicle, for example. In the following description of the embodiments, “rotor” in the claims is referred to as “motor”, and “rotor controller” is referred to as “motor controller”. The “present embodiment” includes the first to third embodiments.

[System configuration]
First, the configuration of the entire motor drive system will be described with reference to FIG. FIG. 1 illustrates a system including one vehicle driving motor. The motor drive system 90 mounted on the hybrid vehicle 99 is a system that drives the motor 80 by converting the DC power of the battery 50 into three-phase AC power by an inverter 60 as a “power converter” and supplying it to the motor 80. is there.

The battery 50 is a chargeable / dischargeable secondary battery such as a nickel metal hydride battery or a lithium ion battery. Instead of the battery, an electric double layer capacitor or the like may be used as a DC power source.
The power supply voltage Vin of the battery 50 is detected by, for example, a voltage sensor. Alternatively, it may be obtained by conversion from the SOC (charge rate) of the battery 50 or the like.
The smoothing capacitor 55 is provided at the input portion of the inverter 60 and smoothes the power supply voltage Vin.

  In the inverter 60, six switching elements 61 to 66 of upper and lower arms are bridge-connected. Specifically, the switching elements 61, 62, and 63 are upper-arm switching elements of the U phase, the V phase, and the W phase, respectively, and the switching elements 64, 65, and 66 are below the U phase, the V phase, and the W phase, respectively. This is an arm switching element. The switching elements 61 to 66 are made of, for example, IGBTs, and are connected in parallel with freewheeling diodes that allow current flowing from the low potential side to the high potential side.

  The inverter 60 operates the switching elements 61 to 66 according to the gate signals UH, UL, VH, VL, WH, WL output from the motor control device 10, thereby converting the power supply voltage Vin input from the battery 50 into an AC voltage. Convert. Then, phase voltages Vu, Vv, and Vw corresponding to the voltage command calculated by the motor control device 10 are applied to the phase windings 81, 82, and 83 of the motor 80.

  The motor 80 is, for example, a permanent magnet type synchronous three-phase AC motor, and is typically a motor generator capable of power running and regenerative operation. The motor 80 has a function as an electric motor that generates torque for driving the drive wheels 95 and a function as a generator that recovers energy by generating electric power transmitted from the engine 91 and the drive wheels 95. The motor 80 is connected to the axle 94 via a gear 93 such as a transmission. The torque generated by the motor 80 drives the driving wheel 95 by rotating the axle 94 via the gear 93.

A current sensor connected to the two-phase winding of the three-phase windings 81, 82, and 83 of the motor 80 is provided with a current sensor that detects the phase current. In the example of FIG. 1, current sensors 72 and 73 for detecting phase currents Iv and Iw are provided in current paths connected to the V-phase winding 82 and the W-phase winding 83, respectively.
The position sensor 85 is a rotation angle sensor such as a resolver and detects the rotation angle of the motor 80, that is, the rotor position θ. Hereinafter, in this specification, the “rotor position” or “position” regarding the motor 80 means an electrical angle position.

The motor control device 10 calculates a voltage command based on the torque command T ^* from the host ECU 11 and the feedback information from the current sensors 72 and 73 and the position sensor 85. Then, based on the pulse pattern set according to the modulation factor calculated from the power supply voltage Vin and the voltage amplitude, the gate signals UH, UL, VH, VL, WH, WL are output to the inverter 60, and the switching elements 61 to 66 are output. Manipulate the behavior. The pulse pattern defines the ON / OFF state according to the rotor position θ of the motor 80. Thereby, energization of the motor 80 is controlled, and the motor 80 outputs a torque according to the torque command T ^* .

By the way, the motor control device 10 needs to switch the pulse pattern in accordance with the modulation rate that changes from time to time, and it is a problem to appropriately suppress the voltage fluctuation at the time of switching.
For example, in the prior art of Patent Document 1 (Japanese Patent Application Laid-Open No. 2014-143831), a dummy pulse is generated so as to ensure a minimum pulse width during the switching transition period, thereby reducing current fluctuation and torque fluctuation at the time of switching the number of pulses. I am trying.
However, in this prior art, it is necessary to generate an extra pattern for generating a dummy pulse, which increases the memory load. Further, voltage fluctuation may occur even when the number of pulses is the same. For example, the case where the ON / OFF switching position is significantly different, such as when switching from the pulse pattern of FIG. 5E to the pulse pattern of FIG.

Therefore, the motor control device 10 of the present embodiment is intended to appropriately suppress voltage fluctuation at the time of pulse pattern switching without generating an extra pattern or the like.
Next, the configuration and operation of the motor control device 10 will be described for each embodiment. In the calculation of the voltage command, the code of the motor control device of the first embodiment that employs the torque feedback control method is “101”, and the code of the motor control device of the third embodiment that adopts the current feedback control method is “103”. To do.

(First embodiment)
The motor control apparatus 101 of 1st Embodiment is demonstrated with reference to FIGS.
The motor control device 101 sets a pulse pattern according to the modulation rate and switches the pulse pattern when the modulation rate is changed. The voltage amplitude calculation unit 13, the modulation rate calculation unit 15, the pulse pattern setting unit 20, And a gate signal generator 18.
Moreover, the motor control apparatus 101 of 1st Embodiment is provided with the dq conversion part 34, the torque estimation part 35, the subtractor 36, and the controller 37 as a structure peculiar to torque feedback control.

Based on the torque command T ^* input from the host ECU and the angular velocity ω of the motor 80, the voltage amplitude calculation unit 13 repeatedly calculates the voltage command amplitude (hereinafter, “voltage amplitude”) Vamp at a predetermined calculation cycle. . Calculations by the following blocks are also repeatedly performed at the calculation timing corresponding to the calculation period of the voltage amplitude Vamp.

  Here, the angular velocity ω [deg / s] is calculated by time-differentiating the position θ [deg] detected by the position sensor 85 with a differentiator 86. Since the angular velocity ω is converted into the rotation speed N [rpm] by multiplying by a proportionality constant, the angular velocity ω and the rotation speed N are used in the same meaning in this specification. As for the angular speed ω, in the hybrid vehicle, the rotational speed of each part to which the rotation of the motor 80 is transmitted, such as the rotational speed of the engine and the axle (wheel or drive shaft), is obtained, and the motor angular speed ω is obtained using the gear ratio. You may convert into.

The modulation factor calculator 15 calculates the modulation factor M based on the power supply voltage Vin and the voltage amplitude Vamp. In the following description, “modulation rate M calculated at the previous calculation timing and reflected in the current drive of inverter 60” is referred to as “current modulation rate M _A ”. The “modulation rate M calculated at the current calculation timing and reflected in the next drive of the inverter 60” is referred to as “next modulation rate M _B ”.

The pulse pattern setting unit 20 acquires the modulation factor M calculated by the modulation factor calculator 15, the voltage phase Vθ calculated by the controller 37, the position θ detected by the position sensor 85, and the angular velocity ω. Then, the pulse pattern setting unit 20 sets the pulse pattern PP according to the modulation rate M calculated by the modulation rate calculation unit 15. The pulse pattern already set according to the current modulation factor M _A is referred to as “current pulse pattern PP _A ”, and the pulse pattern set from now on according to the next modulation factor M _A is referred to as “next pulse pattern PP _B”. "

The pulse pattern setting unit 20 sets the switching position θx is the rotor position for switching to the next pulse pattern PP _B from the current pulse pattern PP _A. Then, the set pulse pattern PP and the switching position θx are commanded to the gate signal generation unit 18.
A detailed configuration regarding the setting of the pulse pattern PP and the switching position θx by the pulse pattern setting unit 20 will be described later.

The gate signal generation unit 18 generates the gate signals UH, UL, VH, and VL based on the next pulse pattern PP _B set by the pulse pattern setting unit 20, the switching position θx, and the information on the position θ acquired from the position sensor 85. , WH, WL are generated and output to the inverter 60. Generally, in the switching control of the inverter 60, the switching element pairs of the upper and lower arms that are complementarily turned ON / OFF are simultaneously turned on to prevent the overcurrent from flowing. A dead time DT is provided between the ON periods of the pair. In the dead time DT, both the switching element pairs are turned off. The dead time DT is given by, for example, the gate signal generation unit 18 and also notified to the pulse pattern setting unit 20.

Next, a configuration unique to torque feedback control will be described.
The dq conversion unit 34 acquires the phase current detection value from the current sensors 72 and 73. In this embodiment, detected values of the V-phase current Iv and the W-phase current Iw are input from the current sensors 72 and 73 provided for the V-phase and the W-phase, and the remaining U-phase current Iu is estimated based on Kirchhoff's law. doing. In other embodiments, any two-phase current may be detected, and a three-phase current may be detected. Or you may employ | adopt the technique which estimates the other two-phase electric current based on the electric current detection value of one phase.
The dq conversion unit 34 dq converts the three-phase current detection values Iu, Iv, and Iw into dq-axis currents Id and Iq using the position θ.

The torque estimation unit 35 calculates the estimated torque T_est using the equation (1) based on the dq axis currents Id and Iq and the circuit constants, and feeds back to the torque command T ^* .
T_est = pm × {Iq × φα + (Ld−Lq) × Id × Iq} (1)
However,
pm: number of pole pairs of motor φα: armature interlinkage magnetic flux of permanent magnet Ld, Lq: d-axis inductance, q-axis inductance

Instead of the estimated torque T_est calculated from the dq axis current, the motor torque may be directly detected by a torque sensor. Further, an approximate torque may be estimated from the current amplitude.
The subtractor 36 subtracts the estimated torque T_est calculated by the torque estimation unit 35 from the torque command T ^* to calculate a torque deviation.
The controller 37 calculates the voltage phase Vθ by PI control calculation or the like so that the torque deviation converges to zero. Thus, the voltage phase Vθ calculated so that the output torque of the motor 80 matches the torque command T ^* is input to the pulse pattern setting unit 20.

Next, a detailed configuration of the pulse pattern setting unit 20 will be described with reference to FIGS.
As shown in FIG. 3, the pulse pattern setting unit 20 includes an ideal switching position calculation unit 21, a current pulse pattern reading unit 22, a next pulse pattern reading unit 23, a switching permission range setting unit 24, a switching position setting unit 25, and a next pulse. A pattern determination unit 26 and a storage unit 29 are included.
Here, it is assumed that the next pulse pattern PP _B is calculated while the inverter 60 is being driven by the current pulse pattern PP _A calculated at the previous calculation timing.

Here, the definition and specific example of the pulse pattern will be described with reference to FIGS.
FIG. 4 shows an example of the U-V phase line voltage pulse pattern and the corresponding pulse pattern of the switching element of the upper arm of the U phase and the V phase.
In each phase pulse pattern, there are 7 rising edges (ON) and 7 falling edges (OFF) in one electrical cycle, that is, in the range of electrical angle 360 [deg]. When one ON / OFF reciprocation is counted as one pulse, the number of pulses is seven. In the line voltage pulse pattern, the electrical (1/2) cycle, that is, the number of ON / OFF times in the electrical angle 180 [deg] range corresponds to the number of pulses. Thus, each phase pulse pattern and the line voltage pulse pattern correspond to each other.

As shown in FIGS. 5 and 6, the pulse pattern of one phase (for example, U phase) among the three phases is set with a section of an electrical angle of 90 [deg] as one unit.
Then, the pulse pattern of electrical angles 90 to 180 [deg] is set by inverting the pulse pattern of electrical angles 0 to 90 [deg] around the electrical angle 90 [deg] as a line symmetry.
Also, the pulse pattern of electrical angles 180 to 360 [deg] is set by inverting the pulse pattern of electrical angles 0 to 180 [deg] around the electrical angle 180 [deg] as a point symmetry. “Point symmetry” means to invert line symmetry and to invert the on and off sides of the pulse.
By shifting the pulse pattern set for one phase (for example, U phase) by an electrical angle of ± 120 [deg], another two-phase (V phase, W phase) pulse pattern is set.

5 and 6 show examples of 10 kinds of pulse patterns with different modulation rates M corresponding thereto. Each pulse pattern differs in the position, pulse width, number of pulses, etc. of each pulse.
The corresponding modulation factor M increases in order from FIG. 5A to FIG. 5E and further from FIG. 6F to FIG. 6J. As the modulation factor M increases, the total ON period of pulses in the electrical angle range of 0 to 90 [deg] becomes longer and the number of pulses tends to decrease.
The storage unit 29 of the pulse pattern setting unit 20 stores a plurality of pulse patterns set in advance for each 1% of the modulation rate M, for example.

Next, the calculation of each block in FIG. 3 will be described.
Ideal switching position calculation unit 21, based on the current modulation factor M _A and the next modulation factor M _B, a "rotor position and the current fundamental wave voltage value and the next fundamental voltage value matches""ideal switching The position θxi ”is calculated.
FIG. 7A shows a sine wave fundamental wave voltage corresponding to the pulse pattern.
FIG. 7B shows how the fundamental voltage changes when the current modulation factor M _A is switched to the next modulation factor M _B. The amplitude of the fundamental wave voltage corresponding to the current modulation factor M _A is A, the amplitude of the fundamental wave voltage corresponding to the next modulation factor M _B is B, the rotor position of the motor 80 is θ, and the current and next fundamental wave voltages are When the phase shift is α, the fundamental voltage value at the rotor position θ is expressed by equations (2.1) and (2.2). In the example of FIG. 7B, A> B.
Current fundamental voltage value = Asinθ (2.1)
Next-time fundamental wave voltage value = Bsin (θ + α) (2.2)

  As shown in FIG. 7B, assuming that the phase shift α = 0 and switching at the switching position θx = 90 [deg], the fundamental wave voltage value changes discontinuously from A to B at the time of switching. Variations occur. On the other hand, as shown in FIG. 7C, an appropriate phase shift α is set for the next fundamental wave voltage, and the fundamental wave at the time of switching is switched by switching at the switching position θx = (90−α) [deg]. The voltage value can be continuously changed. The switching position θx at this time is referred to as “ideal switching position θxi”.

Next, derivation of the ideal switching position θxi will be described. From equations (2.1) and (2.2), equation (3.1) holds when the current and next fundamental wave voltage values match.
Asin θ = Bsin (θ + α) (3.1)
Here, if θ = 0 [deg],
0 = Bsinα
It is. Therefore, when α = 0 and 180 [deg], Expression (3.1) is established. That is, theoretically, 0 and 180 [deg] can be the ideal switching position θxi.

However, as shown in FIG. 7A, the positions of 0 and 180 [deg] are basically pulse edges. In addition, since relatively narrow pulses are concentrated in the vicinity of 0 and 180 [deg], it is difficult to secure a later-described switching permission range.
Therefore, the ideal switching position θxi is preferably set to a position where the phase shift is other than 0 and 180 [deg], for example, near 90 or 270 [deg].

First, as shown in FIG. 8A, a case where A <B, that is, a case where the next modulation rate M _B increases from the current modulation rate M _A will be described.
By transforming the right side of Equation (3.1) and rearranging A, Equation (3.2) is obtained.
Asin θ = B sin θ cos α + B cos θ sin α
A = Bcos α + B sin α / tan θ (3.2)
If θ = 90 [deg] in equation (3.2), the second term on the right side becomes 0, and equation (3.3) is obtained.
A = Bcosα (3.3)
Therefore, the phase shift α at θ = 90 [deg] is expressed by Expression (3.4).
α = cos ⁻¹ (A / B) (3.4)

For example, when the modulation factor M increases from 100% to 101%, (A / B) = (100/101) ≈0.99 and α≈0.14 [rad] ≈8.0 [deg]. . Then, the maximum value corresponding to the amplitude A at the position 90 [deg] of the current fundamental wave voltage and the position of the next fundamental wave voltage “the voltage value is maximum (= amplitude B) are delayed by a phase shift α. "Voltage value at position" matches.
Therefore, when A <B, the fundamental pulse voltage is continuously changed by advancing the next pulse pattern PP _B by the phase shift α at the time of switching and switching at the ideal switching position θxi of 90 [deg]. Can do.

FIG. 8B shows a case where A> B, that is, the next modulation rate M _B is smaller than the current modulation rate M _A. In this case, “ξ = θ + α” is set, and equation (3.1) is rewritten into equation (4.1). In FIG. 8B, the ξ axis is shown with the θ axis offset by α.
Asin (ξ−α) = Bsinξ (4.1)
By transforming the left side of Equation (4.1) and rearranging B, Equation (4.2) is obtained.
Asinξcosα−Acosξsinα = Bsinξ
Acos α-Asin α / tan ξ = B (4.2)
In Equation (4.2), if ξ = 90 [deg], that is, θ = (90−α) [deg], the second term on the left side becomes 0, and Equation (4.3) is obtained.
Acos α = B (4.3)
Therefore, the phase shift α at θ = (90−α) [deg] is expressed by Expression (4.4).
α = cos ⁻¹ (B / A) (4.4)

For example, when the modulation factor M decreases from 101% to 100%, (B / A) = (100/101) ≈0.99 and α≈0.14 [rad] ≈8.0 [deg]. . Then, the current fundamental wave voltage value at the position (90−α) ≈82 [deg] matches the maximum value corresponding to the amplitude B of the next fundamental wave voltage. In other words, “the current fundamental wave voltage value at position (90−α) ≈82 [deg]”, “the voltage value at a position earlier by the phase shift α than the position where the voltage value is maximum (= amplitude A)” It becomes.
Therefore, when A> B, the fundamental voltage is continuously changed by advancing the next pulse pattern PP _B by a phase shift α at the time of switching and switching at the ideal switching position θxi (90−α) [deg]. Can be changed. The state at this time is shown in FIG.
In both cases of A <B and A> B, the next pulse pattern PP _B may be delayed by (360−α) [deg] instead of advancing by the phase shift α. However, in order to perform switching quickly, it is basically preferable to advance the phase.

As described above, the ideal switching position calculating section 21 calculates the ideal switching position θxi and phase shift α of the next pulse pattern PP _B.
Then, the current pulse pattern reading section 22 reads the current pulse pattern PP _A is currently being output. Also, the next pulse pattern reading unit 23 reads the next modulation factor M next pulse pattern PP _B map stored in the storage unit 29 and the like of the optimum in accordance with the _B.

Current pulse pattern PP _A and the next pulse pattern PP _B is notified to the switching permission range setting unit 24 and the next pulse pattern decision unit 26. When it is possible to search for a switching position θx that satisfies the switching conditions described below, the next pulse pattern PP _B is basically output. However, if the switching position θx that apply to switching conditions impossible search, there is a possibility that the current pulse pattern PP _A is outputted again.

Switching permission range setting unit 24, depending on the combination of the current pulse pattern PP _A and the next pulse pattern PP _B, in other words, before and after the change the modulation factor M _A, according to the combination of M _B, sets the switching permission range To do. Refer to FIG. 9 and FIG. 10 for the switching permission range.
As shown in FIG. 9, for example, when the pulse pattern is switched at the rotor position where the output voltage of the current pulse pattern PP _A is ON and the output voltage of the next pulse pattern PP _B is OFF, the current pulse pattern PP _A Are interrupted in the middle. As a result, voltage change occurs before and after the switching, and also the current modulation factor M _A does not correspond to the next modulation factor M _B "unintended pulse" is generated. As a result, power fluctuations and torque fluctuations of the motor 80 may occur.

Therefore, as shown in FIG. 10, the switching permission range setting unit 24 sets the rotor position where the output voltage of the pulse pattern does not change, that is, the range of the rotor position where the ON state or the OFF state continues, as the “switching permission range”. Set as. FIG. 10 simply shows only one-phase pulse pattern, but in practice, the rotor position where the output voltage does not change is set as the “switching permission range” for all three-phase pulse patterns. Is preferred.
In addition, the switching permission range setting unit 24 may further acquire information on the dead time DT and the angular velocity ω, and set the switching permission range under more preferable conditions, details of which will be described later.

The switching position setting unit 25 determines whether or not the ideal switching position θxi calculated by the ideal switching position calculation unit 21 is within the switching permission range set by the switching permission range setting unit 24.
When the ideal switching position θxi is within the switching permission range, the switching position setting unit 25 sets the ideal switching position θxi as the switching position θx. On the other hand, when the ideal switching position θxi is outside the switching permission range, the switching position setting unit 25 sets “the position corrected to the rotor position closest to the ideal switching position θxi within the switching permission range” as the switching position θx.

Next pulse pattern determination unit 26 acquires the position θ and the voltage phase V [theta], and outputs the determined a next pulse pattern PP _B and the switching position θx based on this information. Thus, when the modulation factor M changes, the motor control device 101 switches the pulse pattern within the switching permission range and at the ideal switching position θxi or a position as close as possible.
However, when it is impossible to search for an appropriate switching position θx that satisfies the switching condition from the current pulse pattern PP _A to the next pulse pattern PP _B , the next pulse pattern determination unit 26 outputs the current pulse pattern PP _A again.

The storage unit 29 stores a plurality of preset pulse patterns as a map or the like so that a switching permission range can be set in accordance with various operating condition change patterns of the motor 80 that can be assumed. Further, when a pulse pattern corresponding to a combination of the current and next modulation factors M _A and M _B not stored in the past is newly calculated, the storage unit 29 may be made to learn.

As described above, in the present embodiment, the switching permission range is first selected as the switching position θx when the modulation factor M changes and the pulse pattern PP is switched, and then the ideal switching position θxi is further selected. When the ideal switching position θxi is not within the switching permission range, “the rotor position closest to the ideal switching position θxi within the switching permission range” is selected.
By switching the pulse pattern within the switching permission range where the output voltage does not change, it is possible to avoid the occurrence of a voltage change at the time of switching, and to suppress power fluctuations and torque fluctuations.
Further, by switching the pulse pattern at the ideal switching position θxi or the position as close as possible to the ideal switching position θxi, the fundamental voltage value can be continuously changed at the time of switching.

Subsequently, a preferable setting of the switching permission range by the switching permission range setting unit 24 will be described with reference to FIGS.
FIG. 11 shows a three-phase pulse pattern of U phase, V phase, and W phase. Each phase pulse pattern is set by shifting the same pulse pattern by 120 [deg]. The switching permission range is set to a rotor position range in which the output voltages of the three-phase pulse patterns continue to be in the ON state or the OFF state, and the voltage vector is constant. Thereby, the electric power fluctuation | variation at the time of switching can be suppressed appropriately about all the phases, maintaining the balance between phases.
To be precise, the position where the output voltage does not change is set in common for a total of six pulse patterns of the three phases before the change and the three phases after the change. One before or after the change is omitted.

FIG. 12 shows pulse patterns before and after the change when the rotation speed [rpm] of the motor 80 is (a) N and (b) 3N.
When the number of revolutions is N, a total of three times of a relatively long two-time switching permission range L and a relatively short one-time switching permission range S are set in the electrical angle 180 [deg].
On the other hand, when the rotational speed is 3N, the switching permission range S in which the switching of the pulse pattern is not possible due to insufficient time width is excluded, and only the switching permission range L is set. That is, the rotor position range that is less than the predetermined time during high rotation is excluded from the switching permission range.
Thus, the switching permission range setting unit 24 sets the switching permission range according to the rotation speed N. As a result, it is possible to prevent an inappropriate switching permission range from being set particularly during high rotation.

FIG. 13 shows a switching permission range set in consideration of the calculation cycle of the voltage amplitude Vamp by the voltage amplitude calculation unit 13 or the calculation cycle of the voltage phase command Vθ by the controller 37.
Even if the output voltage of the pulse pattern is in the rotor position range where the ON state or the OFF state continues, the period shorter than the calculation cycle Tc is excluded from the switching permission range. That is, the switching permission range setting unit 24 sets the switching permission range so that the period is equal to or longer than the voltage command calculation cycle Tc. Thereby, the feasibility of the control calculation accompanying the switching of the pulse pattern can be appropriately ensured.

FIG. 14 shows a switching permission range set in consideration of the dead time DT. In the dead time DT, each phase switching element pair that performs a complementary switching operation in the inverter 60 is turned off. For this reason, if the period just before the end of the switching permission range overlaps with the dead time DT, the pulse is substantially cut when the pulse pattern is switched just before the end of the switching permission range. Note that “DT” in the figure is strictly “position range corresponding to the dead time DT” and is not necessarily the dead time DT itself set by the gate signal generation unit 18, but for convenience, Use the time symbol.
Therefore, the switching permission range setting unit 24 can prevent the pulses from being deleted by setting the switching permission range while avoiding the position corresponding to the dead time DT. Further, based on the same idea, the switching permission range may be set in consideration of element characteristics such as an operation delay time from the gate signal output.

Next, inverter drive processing by the motor control device 101 will be described with reference to the flowcharts of FIGS. 15 and 16. In the description of the flowchart below, the symbol “S” means a step. Here, it is assumed that the next pulse pattern PP _B is calculated while the inverter 60 is being driven by the current pulse pattern PP _A calculated by the previous control.

First, the main flowchart of FIG. 15 is referred.
In S11, the motor control device 101 acquires the position θ and the angular velocity ω (the number of rotations N).
In S12, the voltage amplitude calculation unit 13 calculates the voltage amplitude Vamp based on the torque command T ^* and the angular velocity ω.
In S13, the modulation factor computation unit 15 calculates the next modulation factor M _B based on the power supply voltage Vin and the voltage amplitude Vamp.

In S16, the pulse pattern setting unit 20 acquires the next modulation factor M _B and the current modulation factor M _A. When the next modulation factor M _B is equal to the current modulation factor M _A within a predetermined error range (S17: YES), no pulse pattern is changed in S31.
When the next modulation factor M _B exceeds the error range and differs from the current modulation factor M _A (S17: NO), the process proceeds to “switching position and pulse pattern setting process” in S20. According to the result set in S20, the pulse pattern setting unit 20 changes and outputs the pulse pattern in S32.

For details of the “switching position and pulse pattern setting process” in S20, refer to the sub-flowchart of FIG.
In S21, the ideal switching position calculation unit 21, based on the current modulation factor M _A and the next modulation factor M _B, calculates the ideal switching position θxi and phase shift alpha.

In S22, the current pulse pattern reading section 22 reads the current pulse pattern PP _A is currently being output. Also, the next pulse pattern reading unit 23 reads the next pulse pattern PP _B map stored in the storage unit 29 and the like in accordance with the next modulation factor M _B.
The current pulse pattern PP _A and the next pulse pattern PP _B read in S22 are notified to the switching permission range setting unit 24. In S23, the switching permission range setting unit 24 further acquires information such as dead time DT, angular velocity ω (rotation speed N) and the like, and in S24, sets the switching permission range based on these information.

In S25, the switching position setting unit 25 determines whether or not the ideal switching position θxi is within the switching permission range. When the ideal switching position θxi is within the switching permission range (S25: YES), the switching position setting unit 25 sets the ideal switching position θxi as the switching position θx in S26.
On the other hand, when the ideal switching position θxi is outside the switching permission range (S25: NO), the switching position setting unit 25, in S27, “a position corrected to the rotor position closest to the ideal switching position θxi within the switching permission range”. Is set as the switching position θx.
In S28, the next pulse pattern determination unit 26 acquires the position θ and the voltage phase V [theta], and outputs the determined a next pulse pattern PP _B and the switching position [theta] x. Incidentally, omitted for the case of outputting the current pulse pattern PP _A again.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS.
FIG. 17 shows pulse patterns before and after the change when a sharp change in the rotation speed and modulation rate occurs as a problem to be solved by the second embodiment. Here, an example in which the rotation speed and the modulation rate are particularly rapidly reduced is assumed. This corresponds to a case where the vehicle collides with an obstacle while traveling. In this case, the electrical angle cycle becomes abruptly long, and switching is delayed depending on the switching condition of the pulse pattern. As a result, there is a risk of element destruction due to overvoltage and overcurrent.

In order to prevent such a situation, the second embodiment employs a configuration in which an abnormality treatment is performed when a sudden change in the rotation speed or the modulation rate occurs.
In the flowchart of the inverter driving process shown in FIG. 18, S14, S15, S18, S19, and S33 are added to FIG.
In S14, the rotational speed change rate RN is calculated from the ratio between the current rotational speed and the next rotational speed. In S18, the modulation rate change rate RM is calculated from the ratio between the current modulation rate M _A and the next modulation rate M _B. The rate of change RN and RM when the rotation speed or the modulation rate decreases is defined by an absolute value.

  Threshold values for discriminating between normal values and abnormal values are set for the rotation speed and the change rate of the modulation rate. When the rotational speed change rate RN is less than or equal to the threshold value (S15: YES) and when the modulation rate change rate RM is less than or equal to the threshold value (S19: YES), it is determined to be normal, and the process proceeds to the next steps S16 and S20, respectively. To do.

When the rotational speed change rate RN exceeds the threshold value (S15: NO), or when the modulation rate change rate RM exceeds the threshold value (S19: NO), it is determined to be abnormal, and the process proceeds to S33.
In S33, forcible switching of the pulse pattern is performed as an abnormality treatment. That is, the pulse pattern setting unit 20 forcibly switches to a specific pulse pattern for abnormality treatment without using a pulse pattern set by normal calculation.

For example, it is assumed that the rotation speed or the modulation rate is rapidly reduced and the reduction rate exceeds a threshold value. At this time, due to the rapid deceleration of the motor 80, the counter electromotive voltage is rapidly decreased, and a voltage larger than the originally required voltage is applied to the inverter 60. The pulse pattern setting unit 20 forcibly switches to a pulse pattern that can output the originally required voltage. Thereby, an overvoltage is applied to the switching elements 61 to 66 and the like, and it is possible to prevent an overcurrent from flowing.
More preferably, the overcurrent can be more preferably suppressed by forcibly switching the pulse pattern and simultaneously setting the torque command T ^* to 0.

(Third embodiment)
A rotating machine control device according to a third embodiment will be described with reference to FIG.
The motor control device 103 of the third embodiment is a current feedback control type control device. As a configuration different from that of the first embodiment, a current command calculation unit 31, a subtractor 32, a controller 33, and a voltage amplitude phase calculation unit 14 are provided. On the other hand, the torque estimation unit 35 and the subtractor 36 included in the first embodiment are not provided.

  In the first embodiment, the voltage amplitude calculation unit 13 calculates the voltage amplitude Vamp, and the controller 37 calculates the voltage phase Vθ. On the other hand, the voltage amplitude phase calculation unit 14 of the third embodiment uses the voltage amplitude Vamp. Both Vamp and voltage phase Vθ are calculated.

The current command calculation unit 31 calculates dq-axis current command values Id ^* and Iq ^* using a map or a mathematical formula based on the torque command T ^* acquired from the vehicle control device or the like.
The subtractor 32 subtracts the dq axis currents Id and Iq fed back from the dq converter 34 from the dq axis current command values Id ^* and Iq ^* to calculate a dq axis current deviation.
The controller 33 calculates the dq-axis voltage command values Vd ^* and Vq ^* by PI control calculation or the like so that the dq-axis current deviation converges to zero.

The voltage amplitude phase calculation unit 14 calculates the amplitude Vamp and the phase Vθ of the voltage command vector based on the dq axis voltage command values Vd ^* and Vq ^* . When the voltage phase Vθ is defined in the counterclockwise direction with the + Vd axis as a reference, the voltage phase Vθ [deg] is calculated by the following equations (5.1) to (5.3) according to the sign of Vd ^* and Vq ^*. Is done.
[Vd ^* > 0, Vq ^* ≧ 0] Vθ = arctan (Vq ^* / Vd ^* ) (5.1)
[Vd ^* <0] Vθ = arctan (Vq ^* / Vd ^* ) + 180 (5.2)
[Vd ^* > 0, Vq ^* <0] Vθ = arctan (Vq ^* / Vd ^* ) + 360
... (5.3)

  The voltage amplitude Vamp is output to the modulation factor calculation unit 15, and the voltage phase Vθ is output to the pulse pattern setting unit 20. Thereafter, the third embodiment is the same as the first embodiment particularly with respect to the configuration and operational effects of the pulse pattern setting unit 20.

(Other embodiments)
(A) “Current” and “next” such as “current / next modulation rate” and “current / next pulse pattern” used in the description of the above embodiments are terms indicating relative relationships in the calculation order. Not too much. In other words, it does not limit the absolute standard of “present”. Depending on when the calculation timing reference is determined, “current” may mean the immediate future, and “next” may mean the future a little further.

  (A) When the modulation factor M is input, the pulse pattern setting unit 20 is not limited to a configuration in which an optimal pattern is read from a plurality of pulse patterns stored in advance in the storage unit, and calculates an optimal pulse pattern every time. You may make it do.

(C) The present invention may be applied to a system including a DCDC converter between the battery 50 and the inverter 60.
(D) The rotating machine to be controlled in the present invention is not limited to a three-phase rotating machine, and may be a four-phase or more multi-phase rotating machine.

(E) The present invention may be applied not only to a rotating machine used as a main motor of a hybrid vehicle or an electric vehicle, but also to a rotating machine used in an auxiliary motor for a vehicle, an elevator other than a vehicle, a general machine, or the like. Good.
As mentioned above, this invention is not limited to the said embodiment at all, In the range which does not deviate from the meaning of invention, it can implement with a various form.

101, 103 ... motor control device (control device for rotating machine),
15: Modulation rate calculation unit,
20 ... pulse pattern setting unit,
60: Inverter (power converter),
61-66... Switching elements,
80: Motor (rotating machine).

Claims (12)

ON / OFF states are defined for a plurality of switching elements (61 to 66) of a power converter (60) for supplying power to a multiphase rotating machine (80) of three or more phases according to the rotor position of the rotating machine. A gate signal based on a pulse pattern to be output, and a control device for a rotating machine that controls energization of the rotating machine,
A modulation factor calculation unit (15) for calculating the modulation factor based on the power supply voltage and the voltage amplitude;
A pulse pattern setting unit (20) for setting a pulse pattern according to the modulation rate calculated by the modulation rate calculation unit;
With
The pulse pattern setting unit
The range of the rotor position where the output voltage of the pulse pattern of at least one of the phases continues ON or OFF is set as a switching permission range, and the pulse pattern is switched within the switching permission range when the modulation rate changes. Control device for rotating machine. The pulse pattern setting unit
Based on the ratio of the current and next fundamental voltage amplitudes with respect to the fundamental voltage corresponding to the modulation factor computed at a predetermined computation period in the modulation factor computation unit, the current fundamental voltage value and the next fundamental voltage value Is calculated as the ideal switching position,
When the ideal switching position is within the switching permission range, the pulse pattern is switched at the ideal switching position,
2. The rotating machine control device according to claim 1, wherein when the ideal switching position is outside the switching permission range, the pulse pattern is switched at the switching position corrected to the rotor position closest to the ideal switching position within the switching permission range. .   3. The control device for a rotating machine according to claim 2, wherein the ideal switching position is set to a position other than 0 [deg] and 180 [deg] for a phase shift of the current and next fundamental wave voltages. The pulse pattern setting unit
The rotor position range in which the output voltages of the pulse patterns of all phases continue to be in the ON state or the OFF state and the voltage vector is constant is set as the switching permission range. Rotating machine control device.   The control device for a rotating machine according to any one of claims 1 to 4, wherein the switching permission range is set according to a combination of modulation rates before and after the change.   The control device for a rotating machine according to any one of claims 1 to 5, wherein the switching permission range is set according to a rotational speed of the rotating machine.   The switching permission range is set so as to avoid a position range corresponding to a dead time in which both of the switching element pairs that are complementarily turned on / off in the power converter are turned off. The control apparatus of the described rotating machine.   The control device for a rotating machine according to any one of claims 1 to 7, wherein the switching permission range is set to be a period equal to or longer than a calculation period of a voltage command. The pulse pattern setting unit
The control device for a rotating machine according to any one of claims 1 to 8, wherein the pulse pattern is forcibly switched as an abnormality treatment when the change rate of the rotation speed or the modulation rate exceeds a threshold value. The pulse pattern setting unit
The control device for a rotating machine according to claim 9, wherein when the number of rotations or the rate of decrease in the modulation rate exceeds a threshold value, the pulse pattern is forcibly switched as an abnormality treatment. The pulse pattern setting unit
A storage unit (29) for storing a plurality of pulse patterns set in advance so that the switching permission range can be set according to an operating condition change pattern of a rotating machine that can be assumed;
The control device for a rotating machine according to any one of claims 1 to 10, wherein an appropriate pulse pattern is read from the storage unit in accordance with an input modulation factor.   The control apparatus of the rotary machine as described in any one of Claims 1-11 applied to the drive system of the main machine motor which is a motive power source of a vehicle.

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