Control device for AC rotating electric machines

Abstract

To provide a control device of an AC rotary electric machine, which reduces a data amount of setting data required to set a current command value and can secure control accuracy of torque and a modulation rate with respect to an error factor.SOLUTION: A control device of an AC rotary electric machine calculates a detection value of a speed voltage ratio being a ratio between a detection value of rotary speed and DC voltage, corrects the detection value of the speed voltage ratio based on deviation between a modulation rate command value and a real modulation rate, calculates a speed voltage ratio after correction, refers to current command value setting data in which a relationship between a torque command value, the speed voltage ratio and a the current command value is previously set, and calculates a current torque command value and the current command value corresponding to the speed voltage ratio after correction.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] This application relates to a control device for an AC rotating electric machine.

Background Art

[0002] In an AC rotating electric machine, the induced voltage increases as the rotational speed increases, and the effective value of the voltage command value increases. However, voltage saturation occurs due to the limitation of the DC voltage supplied to the inverter. When voltage saturation occurs, a desired current cannot be passed, and the output torque decreases. Also, the lower the DC voltage, the more likely voltage saturation is to occur.

[0003] Therefore, in the technologies of Patent Document 1 and Patent Document 2, by calculating a current command value based on the torque command value, the rotational speed, and the DC voltage, a current command value that can avoid voltage saturation is calculated, and a desired torque is output.

[0004] Also, in the technologies of Patent Document 2 and Patent Document 3, based on the effective value of the voltage command value and the modulation ratio calculated from the effective value of the voltage command value, by calculating the current command value, robust control is performed against error factors such as parameter error or voltage error.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] One possible method involves calculating the current command value by referring to a map data set in advance, which contains the relationship between the torque command value, rotational speed, DC voltage, and current command value. This current command value is then corrected by performing flux weakening control to reduce the deviation between the modulation rate command value and the actual modulation rate. For example, this method combines the methods described in Patent Documents 1 and 3. However, since the current command value is adjusted after it has been calculated by referring to the map data, it changes from the voltage command value calculated according to the torque command value by referring to the map data, and therefore cannot output torque exactly as specified by the torque command value.

[0007] In contrast, Patent Document 2 corrects the DC voltage according to the modulation rate before generating the map data, so it can output torque according to the torque command value. However, since the map data requires three inputs—torque command value, rotational speed, and DC voltage—there is a problem in that the amount of data is large.

[0008] Therefore, the present invention aims to provide a control device for an AC rotating electric machine that reduces the amount of setting data used to set the current command value, while ensuring control accuracy of torque and modulation rate against variation or error factors. [Means for solving the problem]

[0009] The control device for an AC rotating electric machine according to the present application is a control device for an AC rotating electric machine having an armature winding that controls the AC rotating electric machine via an inverter, A current command value calculation unit calculates a current command value based on the torque command value, the detected rotational speed of the AC rotating electric machine, and the DC voltage supplied to the inverter. A voltage command value calculation unit calculates a voltage command value to be applied to the armature winding based on the current command value, The inverter comprises a PWM control unit that controls the on / off state of a plurality of switching elements based on the voltage command value, The modulation rate is defined as a value corresponding to the ratio of the effective value of the voltage command value to the DC voltage. The current command value calculation unit calculates a detected value of the speed-voltage ratio, which is the ratio of the detected rotational speed to the DC voltage, calculates the actual modulation rate based on the voltage command value and the DC voltage, corrects the detected value of the speed-voltage ratio based on the deviation between the modulation rate command value and the actual modulation rate, and calculates the corrected speed-voltage ratio. The system calculates the current command value corresponding to the current torque command value and the corrected speed-voltage ratio by referring to current command value setting data, which has a predetermined relationship between the torque command value, the speed-voltage ratio, and the current command value. [Effects of the Invention]

[0010] According to the control device for an AC rotating electric machine of the present invention, when the actual modulation rate deviates from the modulation rate command value due to variation or error factors, the current command value calculation unit corrects the detected speed-voltage ratio based on the deviation between the modulation rate command value and the actual modulation rate, calculates the corrected speed-voltage ratio, and, referring to the current command value setting data, calculates the current command value corresponding to the current torque command value and the corrected speed-voltage ratio. Therefore, even when the actual modulation rate deviates from the modulation rate command value due to variation or error factors, the current command value can be changed while maintaining the torque output of the torque command value by correcting the speed-voltage ratio using the current command value setting data that was set when there was no fluctuation, thereby bringing the actual modulation rate closer to the modulation rate command value. The current command value setting data combines the rotational speed and DC voltage into a single speed-voltage ratio, thus reducing the amount of data. Therefore, by using this current command value setting data with reduced data volume as is, it is possible to respond to fluctuations in the modulation rate while maintaining the torque output of the torque command value, thus simplifying the entire control system. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of the AC rotating electric machine and control device according to Embodiment 1. [Figure 2] This is a schematic block diagram of the control device according to Embodiment 1. [Figure 3] This is a schematic hardware configuration diagram of the control device according to Embodiment 1. [Figure 4] It is a block diagram of a current command value calculation unit according to Embodiment 1. [Figure 5] It is a diagram for explaining the setting of a modulation rate command value and the operation regions of respective controls according to Embodiment 1. [Figure 6] It is a diagram for explaining field-weakening control according to Embodiment 1. [Figure 7] It is a diagram for explaining maximum torque / current control according to Embodiment 1. [Figure 8] It is a diagram for explaining the reduction of a modulation rate by an increase correction of a speed voltage ratio according to Embodiment 1. [Figure 9] It is a diagram for explaining the increase of a modulation rate by a decrease correction of a speed voltage ratio according to Embodiment 1. [Figure 10] It is a block diagram of a current command value calculation unit according to Embodiment 2. [Figure 11] It is a block diagram of a current command value calculation unit according to Embodiment 3. [Figure 12] It is a diagram for explaining the setting of a modulation rate command value and the operation regions of respective controls according to Embodiment 4. [Figure 13] It is a diagram for explaining the setting of a modulation rate command value and the operation regions of respective controls according to Embodiment 4.

MODE FOR CARRYING OUT THE INVENTION

[0012] 1. Embodiment 1 A control device 1 for an AC rotating electrical machine according to Embodiment 1 (hereinafter simply referred to as the control device 1) will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of the AC rotating electrical machine 2 and the control device 1 according to the present embodiment.

[0013] 1-1. AC rotating electrical machine The AC rotating electric machine 2 is equipped with an armature winding (hereinafter simply referred to as winding). The AC rotating electric machine 2 comprises a stator and a rotor positioned radially inward of the stator. Multiple phase windings are provided on the stator. In this embodiment, three phase windings Cu, Cv, and Cw of U, V, and W phases are provided. The three phase windings Cu, Cv, and Cw are connected in a star configuration. The three phase windings may also be connected in a delta configuration. The AC rotating electric machine 2 is a permanent magnet type synchronous rotating electric machine, and permanent magnets are provided on the rotor. In this embodiment, the permanent magnets are embedded inside the electromagnetic steel sheet of the rotor. The permanent magnets may also be attached to the outer surface of the rotor.

[0014] The AC rotating electric machine 2 is equipped with a rotation sensor 16 that outputs an electrical signal corresponding to the rotation angle of the rotor. The rotation sensor 16 may be a Hall element, an encoder, or a resolver. The output signal of the rotation sensor 16 is input to the control device 1.

[0015] 1-2. Inverters, etc. The inverter 20 is a power converter that performs power conversion between the DC power supply 10 and the three-phase windings, and has multiple switching elements. The inverter 20 has three sets of series circuits (legs) corresponding to the windings of each of the three phases, in which a high-potential switching element 23H (upper arm) connected in series with a low-potential switching element 23L (lower arm) connected in series with a high-potential switching element connected in series with a low-potential switching element 23L (lower arm) connected with a low-potential switching element with a low-potential side. The connection point of the two switching elements in the series circuit of each phase is connected to the winding of the corresponding phase.

[0016] Specifically, in the series circuit of each phase, the collector terminal of the high-potential switching element 23H is connected to the high-potential wire 14, the emitter terminal of the high-potential switching element 23H is connected to the collector terminal of the low-potential switching element 23L, and the emitter terminal of the low-potential switching element 23L is connected to the low-potential wire 15. The connection point between the high-potential switching element 23H and the low-potential switching element 23L is connected to the winding of the corresponding phase.

[0017] Switching elements include IGBTs (Insulated Gate Bipolar Transistors) with diodes 22 connected in antiparallel, FETs (Field Effect Transistors) with diodes connected in antiparallel, MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) with the function of diodes connected in antiparallel, and bipolar transistors with diodes connected in antiparallel. The gate terminal of each switching element is connected to the control device 1. Each switching element is turned on or off by a control signal output from the control device 1.

[0018] A smoothing capacitor 12 is connected between the high-potential wire 14 and the low-potential wire 15. A power supply voltage sensor 13 is provided to detect the power supply voltage supplied from the DC power supply 10 to the inverter 20. The power supply voltage sensor 13 is connected between the high-potential wire 14 and the low-potential wire 15. The output signal of the power supply voltage sensor 13 is input to the control device 1.

[0019] The current sensor 17 outputs an electrical signal corresponding to the current flowing through the windings of each phase. The current sensor 17 is mounted on the wires of each phase connecting the series circuit of the switching element to the windings. The output signal of the current sensor 17 is input to the control device 1. The current sensor 17 may also be mounted in the series circuit of each phase.

[0020] The DC power supply 10 uses a rechargeable energy storage device (for example, a lithium-ion battery, a nickel-metal hydride battery, or an electric double-layer capacitor). The DC power supply 10 may also be equipped with a DC-DC converter, which is a DC power converter that boosts or decompresses the DC voltage.

[0021] 1-3. Control device 1 The control device 1 controls the AC rotating electric machine 2 via the inverter 20. As shown in Figure 2, the control device 1 includes a rotation detection unit 31, a DC voltage detection unit 32, a current detection unit 33, a current command value calculation unit 34, a voltage command value calculation unit 35, and a PWM control unit 36, etc. Each function of the control device 1 is realized by the processing circuit provided in the control device 1. Specifically, as shown in Figure 3, the control device 1 includes a processing circuit such as a CPU (Central Processing Unit) or other arithmetic processing unit 90 (computer), a storage device 91 that exchanges data with the arithmetic processing unit 90, an input circuit 92 that inputs external signals to the arithmetic processing unit 90, and an output circuit 93 that outputs signals from the arithmetic processing unit 90 to the outside.

[0022] The arithmetic processing unit 90 may include an ASIC (Application Specific Integrated Circuit), an IC (Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), various logic circuits, and various signal processing circuits. Furthermore, multiple arithmetic processing units 90 of the same or different types may be provided, with each unit performing a portion of the processing. The storage device 91 may include a RAM (Random Access Memory) configured to read and write data from the arithmetic processing unit 90, or a ROM (Read Only Memory) configured to read data from the arithmetic processing unit 90. The input circuit 92 is connected to various sensors such as a power supply voltage sensor 13, a rotation sensor 16, and a current sensor 17, as well as switches, and includes an A / D converter that inputs the output signals from these sensors and switches to the arithmetic processing unit 90. The output circuit 93 is connected to electrical loads such as gate drive circuits that drive switching elements on and off, and includes drive circuits that output control signals from the arithmetic processing unit 90 to these electrical loads.

[0023] The functions of the control device 1, such as the control units 31-36 shown in Figure 2, are realized by the arithmetic processing unit 90 executing software (programs) stored in the storage device 91, such as a ROM, and cooperating with other hardware of the control device 1, such as the storage device 91, the input circuit 92, and the output circuit 93. The setting data, such as the modulation rate command value setting data and the current command value setting data used by each of the control units 31-36, is stored in the storage device 91, such as a ROM. The functions of the control device 1 will be described in detail below.

[0024] 1-3-1. Rotation detection unit 31 The rotation detection unit 31 detects the rotor's rotation angle θr and rotational angular velocity ωr (hereinafter also referred to as rotational velocity ωr) in electrical angles. In this embodiment, the rotation detection unit 31 detects the rotor's rotation angle θr and rotational angular velocity ωr based on the output signal of the rotation sensor 16. The rotation detection unit 31 detects the rotation angle θr of the rotor's magnetic pole (N pole) with respect to the winding position of the U-phase. The rotation detection unit 31 may also be configured to estimate the rotation angle without using a rotation sensor, based on current information obtained by superimposing harmonic components on the current command value (a so-called sensorless method).

[0025] 1-3-2. DC voltage detection unit 32 The DC voltage detection unit 32 detects the DC voltage Vdcr supplied from the DC power supply 10 to the inverter 20. In this embodiment, the DC voltage detection unit 32 detects the DC voltage Vdcr based on the output signal of the power supply voltage sensor 13. If the DC voltage Vdc is not variable and is set to a specified value, the power supply voltage sensor 13 may not be provided, and a preset DC voltage setting may be used instead of the detected DC voltage value Vdcr.

[0026] 1-3-3. Current detection unit 33 The current detection unit 33 detects the currents Iur, Ivr, and Iwr flowing through the three-phase windings. Based on the output signal of the current sensor 17, the current detection unit 33 detects the current Iur flowing through the U-phase winding, the current Ivr flowing through the V-phase winding, and the current Iwr flowing through the W-phase winding. Alternatively, the current sensor 17 may be configured to detect the winding currents of two phases, and the winding current of the remaining phase may be calculated based on the detected values ​​of the two-phase winding currents. For example, the current sensor 17 may detect the winding currents Ivr and Iwr of the V-phase and W-phase, and the winding current Iur of the U-phase may be calculated using Iur = -Ivr - Iwr.

[0027] 1-3-4. Voltage command value calculation unit 35 The voltage command value calculation unit 35 calculates the voltage command value to be applied to the winding based on the current command value calculated by the current command value calculation unit 34, which will be described later.

[0028] In this embodiment, the voltage command value calculation unit 35 calculates the three-phase voltage command values ​​Vuo, Vvo, and Vwo based on the current command values ​​Ido and Iqo for the d axis and q axis.

[0029] The voltage command value calculation unit 35 converts the three-phase current detection values ​​Iur, Ivr, and Iwr into a d-axis current detection value Idr and a q-axis current detection value Iqr by performing three-phase to two-phase conversion and rotational coordinate conversion based on the magnetic pole position θr.

[0030] The d-axis is defined in the direction of the rotation angle of the rotor's magnetic pole (north pole), and the q-axis is defined in a direction that is 90° ahead of the d-axis in terms of electrical angle.

[0031] The voltage command value calculation unit 35 changes the voltage command value Vdo on the d axis by performing feedback control such as proportional-integral control so that the detected current value Idr on the d axis approaches the current command value Ido on the d axis, and changes the voltage command value Vqo on the q axis by performing feedback control such as proportional-integral control so that the detected current value Iqr on the q axis approaches the current command value Iqo on the q axis. In addition, feedforward control may be performed to decouple the d axis current and the q axis current.

[0032] Alternatively, the voltage command value calculation unit 35 may perform feedforward control that changes the current command values ​​Ido and Iqo of the d-axis and q-axis using the electrical constants of the AC rotating electric machine, based on the current command values ​​Ido and Iqo of the d-axis and q-axis, without using the winding current detection value.

[0033] The voltage command value calculation unit 35 converts the voltage command values ​​Vdo and Vqo of the d axis and q axis into three-phase voltage command values ​​Vuo, Vvo, and Vwo by performing fixed coordinate transformation and two-phase to three-phase transformation based on the magnetic pole position θr. In this embodiment, the voltage command value calculation unit 35 applies amplitude reduction modulation such as third harmonic superposition, min-max method (pseudo-third harmonic superposition), two-phase modulation, and trapezoidal wave modulation to the three-phase voltage command values ​​so as not to change the line voltage. Note that the application of amplitude reduction modulation is not required.

[0034] The voltage command value calculation unit 35 limits the three-phase voltage command values ​​Vuo, Vvo, and Vwo to upper and lower limits based on the amplitude of the carrier wave.

[0035] When amplitude reduction modulation is applied, if the modulation rate M calculated by equations (1) to (3) described later becomes greater than 1, the amplitudes of the three-phase voltage command values ​​Vuo, Vvo, and Vwo after amplitude reduction modulation will exceed half the value of the DC voltage Vdc, resulting in a state of voltage saturation (overmodulation). If amplitude reduction modulation is not applied, if the modulation rate M becomes greater than √3 / 2 (≒0.866), the amplitudes of the three-phase voltage command values ​​Vuo, Vvo, and Vwo will exceed half the value of the DC voltage Vdc, resulting in a state of voltage saturation (overmodulation).

[0036] 1-3-5. PWM control unit 36 The PWM control unit 36 ​​controls the on / off state of multiple switching elements by PWM (Pulse Width Modulation) control based on voltage command values. In this embodiment, the PWM control unit 36 ​​generates switching signals to turn each phase's switching element on or off by comparing each of the three phase voltage command values ​​with a carrier wave. The carrier wave is defined as a triangular wave that oscillates around 0 at the carrier frequency with an amplitude equal to half the DC voltage Vdcr. The PWM control unit 36 ​​turns on the switching signal if the voltage command value exceeds the carrier wave, and turns off the switching signal if the voltage command value falls below the carrier wave. The switching signal is transmitted directly to the switching element on the high-potential side, and an inverted switching signal is transmitted to the switching element on the low-potential side. Each switching signal is input to the gate terminal of each switching element of the inverter 20 via a gate drive circuit, turning each switching element on or off.

[0037] 1-3-6. Current command value calculation unit 34 The current command value calculation unit 34 calculates the current command value based on the torque command value To, the detected rotational speed value ωr, and the detected DC voltage value Vdcr. The torque command value To may be transmitted from an external control device or calculated internally within the control device 1.

[0038] In this embodiment, as shown in Figure 4, the current command value calculation unit 34 calculates the detected speed-voltage ratio Rωvr, which is the ratio of the detected rotational speed ωr to the detected DC voltage Vdcr. The current command value calculation unit 34 also calculates the actual modulation rate Mr based on the voltage command value and the detected DC voltage Vdcr, and corrects the detected speed-voltage ratio Rωvr based on the deviation ΔM between the modulation rate command value Mo and the actual modulation rate Mr to calculate the corrected speed-voltage ratio Rωvcrr. The current command value calculation unit 34 then refers to the torque command value To, the speed-voltage ratio Rωv (in this example, = rotational speed ω / DC voltage Vdc), and the current command value, which are related to the current command value setting data that has been set in advance, and calculates the current command value corresponding to the current torque command value To and the corrected speed-voltage ratio Rωvcrr. Here, the modulation rate M is a value corresponding to the ratio of the effective value of the voltage command value to the DC voltage Vdc.

[0039] <Calculation of actual modulation rate Mr> As described above, the current command value calculation unit 34 calculates the actual modulation rate Mr based on the voltage command value and the detected DC voltage Vdcr. The voltage command value used is the voltage command value calculated in the previous calculation cycle. In this embodiment, the current command value calculation unit 34 calculates the effective value Ve of the voltage command value based on the three-phase voltage command values ​​Vuo, Vvo, and Vwo using the following equation.

number

[0040] Alternatively, the current command value calculation unit 34 may calculate the effective value Ve of the voltage command value based on the voltage command values ​​Vdo and Vqo of the d axis and q axis using the following formula.

number

[0041] Then, the current command value calculation unit 34 calculates the actual modulation rate Mr based on the effective value Ve of the voltage command value and the detected value Vdcr of the DC voltage, using the following formula.

number

[0042] In this embodiment, the coefficients of the modulation rate M calculation formulas (1) to (3) are set to 1 / √3 and √6, respectively. However, there are various setting values ​​for different methods, and the coefficient setting values ​​differ depending on the method. Therefore, coefficients different from those in (1) to (3) may be set. As described above, in this embodiment, when amplitude reduction modulation is applied, if the modulation rate M becomes greater than 1, the amplitudes of the three-phase voltage command values ​​Vuo, Vvo, and Vwo after amplitude reduction modulation will exceed half the value of the DC voltage Vdc, resulting in a state of voltage saturation (overmodulation). The maximum value of the modulation rate M is 2 × √3 / π (≒ 1.10), where the voltage command value becomes a square wave, and this is the value during 1-pulse control, which will be described later.

[0043] <Setting the modulation rate command value Mo> The current command value calculation unit 34 sets the modulation ratio command value Mo. In the present embodiment, the current command value calculation unit 34 refers to the modulation ratio command value setting data in which the relationship among the torque command value To, the speed voltage ratio Rωv, and the modulation ratio command value Mo is preset, and calculates the modulation ratio command value Mo corresponding to the current torque command value To and the detected value Rωvr of the current speed voltage ratio. The modulation ratio command value setting data is set to correspond to the current command value setting data described later. For example, map data is used as the modulation ratio command value setting data. For example, as shown in FIG. 5, in the modulation ratio command value setting data, in the operation region of the field weakening control described later, it is set to 1.0 < Mo < 1.10, and in the operation region of the basic control (maximum torque / current control) described later, it is set to 0 ≦ Mo ≦ 1.0. As will be described later, in the operation region of the basic control, basically, the current command value does not change according to the change in the corrected speed voltage ratio Rωvcrr changed by the feedback control of the modulation ratio. Therefore, the modulation ratio command value Mo in the operation region of the basic control does not necessarily need to be strictly set (for example, it may be set to Mo = 1.0). Also, in the operation region of the field weakening control, when the modulation ratio command value Mo is set to a fixed value, the current command value calculation unit 34 may set the modulation ratio command value Mo to a preset fixed value (for example, 1.05) corresponding to the modulation ratio command value in the operation region of the field weakening control without using map data.

[0044] The current command value calculation unit 34 may change the modulation ratio command value Mo based on at least one of the detected value ωr of the rotational speed, the torque command value To, the detected value or estimated value of the torque of the AC rotating electrical machine, the current command value, the current detected value, and the actual modulation ratio Mr. Also, a value obtained by performing low-pass filter processing on the modulation ratio command value Mo may be used. In this case, the response when the modulation ratio command value Mo is changed can be smoothed.

[0045] <Correction of the detected value Rωvr of the speed voltage ratio> As described above, the current command value calculation unit 34 calculates the detected speed-voltage ratio Rωvr, which is the ratio of the detected rotational speed ωr to the detected DC voltage Vdcr. In this embodiment, as shown in the following equation, the current command value calculation unit 34 calculates the detected speed-voltage ratio Rωvr by dividing the detected rotational speed ωr by the detected DC voltage Vdcr. Since the rotational speed ω is the numerator, the resolution of the speed-voltage ratio Rωv does not change with respect to increases or decreases in rotational speed ω, making it easier to set the current command value setting data, which will be described later.

number

[0046] The current command value calculation unit 34 may also calculate the speed-voltage ratio detection value Rωvr by dividing the detected DC voltage value Vdcr by the detected rotational speed value ωr.

[0047] As described above, the current command value calculation unit 34 corrects the detected speed-voltage ratio Rωvr based on the deviation ΔM between the modulation rate command value Mo and the actual modulation rate Mr, and calculates the corrected speed-voltage ratio Rωvcrr.

[0048] The current command value calculation unit 34 changes the correction value Kr for the detected speed voltage ratio Rωvr so that the corrected speed voltage ratio Rωvcrr decreases when the actual modulation rate Mr is smaller than the modulation rate command value Mo, and changes the correction value Kr so that the corrected speed voltage ratio Rωvcrr increases when the actual modulation rate Mr is larger than the modulation rate command value Mo.

[0049] In this embodiment, the current command value calculation unit 34 calculates a correction value Kr for the detected speed-voltage ratio Rωvr by feedback control based on the deviation ΔM between the modulation rate command value Mo and the actual modulation rate Mr. In this embodiment, the feedback control includes an integrator, but it may also include one or both of a proportional and a differentiator. Alternatively, various types of feedback control may be used.

[0050] The current command value calculation unit 34 calculates the correction value Kr using the following equation. Here, C(s) represents the feedback controller, and s represents the Laplace operator. Various types of feedback controllers are used, such as integral controllers, integral-proportional controllers, and integral-proportional-derivative controllers.

number

[0051] The current command value calculation unit 34 then calculates the corrected speed-voltage ratio Rωvcrr by multiplying the detected speed-voltage ratio Rωvr by the correction value Kr, as shown in the following equation. Alternatively, the current command value calculation unit 34 may calculate the corrected speed-voltage ratio Rωvcrr by adding the correction value Kr to the detected speed-voltage ratio Rωvr.

number

[0052] <Reference to current command value setting data> As described above, the current command value calculation unit 34 refers to current command value setting data in which the relationship between the torque command value To, the speed voltage ratio Rωv, and the current command value is predetermined, and calculates a current command value corresponding to the current torque command value To and the corrected speed voltage ratio Rωvcrr.

[0053] <Current command value setting data for the operating range of weakened magnetic flux control> In this embodiment, the current command value setting data includes a predefined relationship between the torque command value To, the speed-voltage ratio Rωv, and the current command value that causes the AC rotating electric machine to output a torque of the torque command value To while matching the induced voltage generated in the winding according to the current flowing through the winding and the rotational speed ω, in the operating range where the induced voltage during basic control exceeds the DC voltage Vdc, assuming that basic control is performed. In this embodiment, the basic control is so-called maximum torque / current control.

[0054] The current command value in this operating range is the current command value set by so-called flux weakening control. As shown in Figure 6, in flux weakening control, the d-axis current Id and q-axis current Iq are set at the intersection of the voltage limiting ellipse (constant induced voltage ellipse) shown in equation (7) and the constant torque curve of the torque command value To shown in equation (8) on the rotating coordinate system of the d-axis and q-axis, respectively, where the current command values ​​Ido and Iqo for the d-axis and q-axis are set. In flux weakening control, the d-axis current Id is reduced compared to the basic control, and the flux linkage by the permanent magnet is weakened.

number

number

[0055] Here, Ld is the d-axis inductance, Lq is the q-axis inductance, Ψa is the flux linkage due to the permanent magnet, and Pn is the number of pole pairs. These are electrical constants predetermined by the specifications of the AC rotating electric machine. Mwk is the modulation rate set under the corresponding operating conditions in flux weakening control, and usually coincides with the modulation rate command value Mo.

[0056] The information required to determine the d-axis current Id and q-axis current Iq at the intersection of equations (7) and (8) is the DC voltage Vdc, rotational speed ω, and torque command value To. In equation (7), Vdc / ω of the voltage limiting ellipse corresponds to 1 / speed-voltage ratio Rωv. Therefore, based on the torque command value To and the speed-voltage ratio Rωv, the d-axis and q-axis current command values ​​Ido and Iqo can be set by flux weakening control.

[0057] In the operating range of flux weakening control, the current command value setting data includes the d-axis current command value Ido and the q-axis current command value Iqo, which are set by flux weakening control at each operating point of the torque command value To and the speed-voltage ratio Rωv.

[0058] Figure 5 shows the operating range for maximum torque / current control and the operating range for flux weakening control. Flux weakening control is performed in the high rotational speed and high torque range.

[0059] <Current command value setting data for the operating range of basic control (maximum torque / current control)> In this embodiment, the current command value setting data includes a predefined relationship between the torque command value To, the speed-voltage ratio Rωv, and the current command value obtained by the basic control that causes the AC rotating electric machine to output a torque equal to the torque command value To under the conditions of the torque command value To and the speed-voltage ratio Rωv, in the operating range where the induced voltage during basic control does not exceed the DC voltage Vdc. In this embodiment, the basic control is so-called maximum torque / current control.

[0060] In maximum torque / current control, the current command values ​​Ido and Iqo for the d and q axes are set so that the current required to produce the torque command value To is minimized. The current command value is set at the point of tangency between the constant torque curve and the constant current circle in equation (8). As shown in Figure 7, on the rotating coordinate system of the d and q axes, as the torque command value To increases, the current command value Ido for the d axis is decreased and the current command value Iqo for the q axis is increased along the maximum torque / current curve. The maximum torque / current curve is the trajectory of the currents in the d and q axes that produce the maximum output torque for the same current.

[0061] The boundary between weakened flux control and maximum torque / current control is determined by the speed-voltage ratio Rωv and the torque command value To. Therefore, it is possible to determine whether the operating region is for maximum torque / current control or weakened flux control based on the speed-voltage ratio Rωv and the torque command value To. Thus, the current command values ​​Ido and Iqo for the d-axis and q-axis can be set for maximum torque / current control based on the torque command value To and the speed-voltage ratio Rωv. In the operating region for maximum torque / current control determined by the speed-voltage ratio Rωv, the current command values ​​Ido and Iqo for the d-axis and q-axis are basically set according to the torque command value To. Therefore, the current command values ​​Ido and Iqo for the d-axis and q-axis do not change due to the correction of the speed-voltage ratio Rωv.

[0062] In the current command value setting data for the operating range of maximum torque / current control, the d-axis current command value Ido and q-axis current command value Iqo, which are set by maximum torque / current control at each operating point of the torque command value To and speed voltage ratio Rωv, are pre-set.

[0063] In addition, other control methods may be used as basic control, such as the so-called Id=0 control, which sets the d-axis current command value Ido to 0.

[0064] The current command value setting data consists of d-axis current command value setting data and q-axis current command value setting data. The d-axis current command value setting data has a predefined relationship between the torque command value To, the speed-voltage ratio Rωv, and the d-axis current command value Ido. The q-axis current command value setting data has a predefined relationship between the torque command value To, the speed-voltage ratio Rωv, and the q-axis current command value Iqo. For example, map data can be used as each setting data.

[0065] <Effect of correction of speed-voltage ratio Rωv due to modulation rate deviation> The current command value setting data for the operating range of weakened flux control is basically set so that the actual modulation rate Mr matches the modulation rate command value Mo. However, if electrical constants such as d-axis inductance Ld, q-axis inductance Lq, flux linkage Ψa due to permanent magnets, and winding resistance fluctuate from the electrical constants at the time the current command value setting data was set due to variations such as aging, production variations, and temperature changes, the actual modulation rate Mr will fluctuate from the modulation rate command value Mo. In addition, setting errors in the current command value setting data will cause the actual modulation rate Mr to fluctuate from the modulation rate command value Mo.

[0066] When the actual modulation rate Mr deviates from the modulation rate command value Mo due to variation or error factors, the current command value calculation unit 34 corrects the detected speed-voltage ratio Rωvr based on the deviation ΔM between the modulation rate command value Mo and the actual modulation rate Mr, calculates the corrected speed-voltage ratio Rωvcrr, and, referring to the current command value setting data, calculates the current command value corresponding to the current torque command value To and the corrected speed-voltage ratio Rωvcrr. Therefore, even when the actual modulation rate Mr deviates from the modulation rate command value Mo due to variation or error factors, the current command value can be changed while maintaining the torque output of the torque command value To, thereby bringing the actual modulation rate Mr closer to the modulation rate command value Mo, by using the current command value setting data set when there is no fluctuation and correcting the speed-voltage ratio Rωv. The current command value setting data combines the rotational speed ω and DC voltage Vdc into a single speed-voltage ratio Rωv, thus reducing the amount of data. Therefore, by using the current command value setting data with reduced data volume in this way, it is possible to respond to fluctuations in the modulation rate, thus simplifying the entire control system.

[0067] Figures 8 and 9 show the control behavior in the operating region of flux weakening control. If the actual modulation rate Mr becomes greater than the modulation rate command value Mo due to variation or error factors, the correction value Kr is increased, and the corrected speed-voltage ratio Rωvcrr is increased. As shown in Figure 8, when the corrected speed-voltage ratio Rωvcrr increases, the left side of equation (7) decreases, and the voltage limiting ellipse shrinks. When the voltage limiting ellipse shrinks, the d-axis current Id decreases, and the flux weakening is strengthened, so the effective value of the voltage command value decreases, the actual modulation rate Mr decreases, and the actual modulation rate Mr is brought closer to the modulation rate command value Mo.

[0068] If the actual modulation rate Mr becomes smaller than the modulation rate command value Mo due to variation or error factors, the correction value Kr is reduced, and the corrected speed-voltage ratio Rωvcrr is reduced. As shown in Figure 9, when the corrected speed-voltage ratio Rωvcrr is reduced, the left side of equation (7) increases, and the voltage limiting ellipse expands. When the voltage limiting ellipse expands, the d-axis current Id increases, and the weakening flux is weakened, so the effective value of the voltage command value increases, the actual modulation rate Mr increases, and the actual modulation rate Mr is brought closer to the modulation rate command value Mo.

[0069] Thus, even if the actual modulation rate Mr deviates from the modulation rate command value Mo due to variation or error factors, by correcting the detected speed-voltage ratio Rωvr based on the deviation ΔM between the modulation rate command value Mo and the actual modulation rate Mr, the weakening flux can be increased or decreased using the current command value setting data that was set when there was no modulation rate fluctuation, bringing the actual modulation rate Mr closer to the modulation rate command value Mo.

[0070] <Stopping Correction> If the modulation rate command value Mo is smaller than the value at which voltage saturation (overmodulation) begins (1.0 in this example), and voltage saturation (overmodulation) does not occur, the voltage can be applied to the winding according to the voltage command value. Therefore, there is little need to bring the actual modulation rate Mr closer to the modulation rate command value Mo, and therefore little need to correct the speed-voltage ratio Rωv. Also, if voltage saturation (overmodulation) does not occur, maximum torque / current control is performed, and basically, the current command value changes according to the torque command value To, and the current command value does not change according to the change in the speed-voltage ratio Rωv, so there is little need to correct the speed-voltage ratio Rωv.

[0071] The current command value calculation unit 34 stops the operation of the integrator included in the feedback control or initializes the integral value when the conditions for the detected rotational speed ωr, or the conditions for the modulation rate command value Mo or the actual modulation rate Mr are met.

[0072] As a condition for the detected rotational speed ωr, the current command value calculation unit 34 stops the operation of the integrator or initializes the integral value if the detected rotational speed ωr is lower than the base rotational speed. The base rotational speed is the rotational speed at which voltage saturation (overmodulation) begins to occur. As a condition for the modulation rate command value Mo or actual modulation rate Mr, the current command value calculation unit 34 stops the operation of the integrator or initializes the integral value if the modulation rate command value Mo or actual modulation rate Mr is less than the value at which voltage saturation (overmodulation) begins to occur (1.0 in this example).

[0073] This configuration allows the integrator to stop operating or reset the integral value when voltage saturation (overmodulation) does not occur, thus preventing unnecessary correction of the speed voltage ratio Rωv. Furthermore, it prevents the integral value from winding up when voltage saturation (overmodulation) does not occur, and facilitates the restart of the integrator's operation when voltage saturation (overmodulation) does occur.

[0074] Furthermore, the current command value calculation unit 34 sets the correction amount for the detected speed-voltage ratio Rωvr to 0 when the conditions for the detected rotational speed ωr, or the conditions for the modulation rate command value Mo or the actual modulation rate Mr are met, and calculates the detected speed-voltage ratio Rωvr as the corrected speed-voltage ratio Rωvrcrr. In this embodiment, the correction value Kr is set to 1.

[0075] With this configuration, if a voltage saturation (overmodulation) state does not occur, the correction amount can be set to 0, preventing unnecessary correction of the speed-voltage ratio Rωv.

[0076] 2. Embodiment 2 The AC rotating electric machine 2 and control device 1 according to Embodiment 2 will now be described. The same components as those in Embodiment 1 will not be described. The basic configuration of the AC rotating electric machine 2 and control device 1 according to this embodiment is the same as that of Embodiment 1, but it differs from Embodiment 1 in that a normalized speed voltage ratio is used as the speed voltage ratio.

[0077] In this embodiment, as shown in Figure 10, the current command value calculation unit 34 uses a normalized speed voltage ratio Rωvnrm as the speed voltage ratio Rωv, which is obtained by normalizing the speed voltage ratio Rωv with one or more of the modulation rate command value Mo, the DC voltage reference value Vdcbs, and the modulation rate reference value Mbs. In other words, the normalized speed voltage ratio Rωvnrm is used instead of the speed voltage ratio. In this embodiment, the current command value calculation unit 34 calculates the normalized speed voltage ratio Rωvnrm by dividing the speed voltage ratio Rωv by the modulation rate command value Mo and multiplying it by the modulation rate reference value Mbs and the DC voltage reference value Vdcbs, as shown in the following equation. At this time, Mbs and Vdcbs act as gains, and the referenced current command value is calculated according to the values ​​of ω, Vdc, and Mo. The reference value Mbs for modulation rate and the reference value Vdcbs for DC voltage may be pre-set to the most frequently occurring value across the entire operating range, or they may be pre-set to an intermediate value within the range of values ​​that can be taken across the entire operating range. Note that if the modulation rate command value Mo is a fixed value, then Mbs = Mo, and (Mbs / Mo) multiplication is not required.

number

[0078] Furthermore, if the detected speed-voltage ratio Rωvr is calculated by dividing the detected DC voltage Vdcr by the detected rotational speed ωr, then the numerator and denominator of the right-hand side of equation (9) will be reversed.

[0079] The current command value setting data consists of data whose relationship with the torque command value To, the normalized speed-voltage ratio Rωvnrm, and the current command value is predetermined. The modulation rate command value Mo used to set the normalized speed-voltage ratio Rωvnrm is the modulation rate command value Mo set under the conditions of the torque command value To and the speed-voltage ratio Rωv. The current command value setting data is the same as in Embodiment 1, except that the normalized speed-voltage ratio Rωvnrm is used instead of the speed-voltage ratio Rωv, so the explanation is omitted.

[0080] By using the normalized speed-voltage ratio Rωvnrm in the current command value setting data, it becomes easier to set the data even when the modulation rate command value Mo changes significantly. Furthermore, because it is normalized by the DC voltage reference value Vdcbs, it becomes easier to set the data even when the DC voltage Vdc changes significantly due to a DC-DC converter or the like. Also, because it is normalized by the modulation rate reference value Mbs, it becomes easier to set the data even when the modulation rate M changes significantly.

[0081] The current command value calculation unit 34 calculates the normalized speed-voltage ratio detection value Rωvnrmr by normalizing the ratio of the detected rotational speed value ωr to the detected DC voltage value Vdcr (speed-voltage ratio detection value Rωvr) by one or more of the modulation rate command value Mo, a preset DC voltage reference value Vdcbs, and a preset modulation rate reference value Mbs. In this embodiment, as shown in the following equation, the current command value calculation unit 34 calculates the normalized speed-voltage ratio detection value Rωvr (=ωr / Vdcr) by dividing the detected speed-voltage ratio detection value Rωvr (=ωr / Vdcr) by the modulation rate command value Mo and multiplying it by the modulation rate reference value Mbs and the DC voltage reference value Vdcbs. Note that if the modulation rate command value Mo is a fixed value, Mbs = Mo and (Mbs / Mo) multiplication is not required.

number

[0082] With this configuration, the detected value Rωvnrmr of the normalized speed voltage ratio can be changed in a feedforward manner by changing the modulation rate command value Mo, thereby speeding up the response when the modulation rate command value Mo changes.

[0083] The current command value calculation unit 34 calculates a correction value Kr for the detected value Rωvnrmr of the normalized speed voltage ratio by feedback control based on the deviation ΔM between the modulation rate command value Mo and the actual modulation rate Mr. The feedback control includes an integrator, but may also include one or both of a proportional and a differentiator. Alternatively, various types of feedback control may be used.

[0084] In this embodiment, the current command value calculation unit 34 calculates the correction value Kr using the following equation. Here, C(s) represents a feedback controller and s represents the Laplace operator. Various types of feedback controllers can be used as the feedback controller, such as integral controllers, integral proportional controllers, and integral proportional differential controllers. Instead of the first equation in equation (11), the first equation in equation (5) may be used, or Kr = 1 / (1 + Cr) may be used.

number

[0085] The current command value calculation unit 34 then calculates the corrected normalized speed voltage ratio detection value Rωvnrmcrr by multiplying the detected normalized speed voltage ratio Rωvnrmr by the correction value Kr, as shown in the following equation. Alternatively, the current command value calculation unit 34 may add the correction value Kr to the detected normalized speed voltage ratio detection value Rωvnrmr to calculate the corrected normalized speed voltage ratio detection value Rωvnrmcrr.

number

[0086] The current command value calculation unit 34 then refers to the torque command value To, the normalized speed-voltage ratio Rωvnrm, and current command value setting data whose relationship with the current command value is predetermined, and calculates a current command value corresponding to the current torque command value To and the detected value Rωvnrmcrr of the corrected normalized speed-voltage ratio. Note that in equation (12), (1 / Mo) in equation (10) and Mo in the first equation of equation (11) multiply to 1, so a simplified configuration may be adopted by taking this into consideration in advance. That is, (1 / Mo) in equations (9) and (10) and Mo in the first equation of equation (11) do not need to be multiplied.

[0087] 3. Embodiment 3 The AC rotating electric machine 2 and control device 1 according to Embodiment 3 will now be described. The same components as those in Embodiments 1 or 2 described above will be omitted from the description. The basic configuration of the AC rotating electric machine 2 and control device 1 according to this embodiment is the same as that of Embodiments 1 or 2, but it differs from Embodiments 1 or 2 in that the current command value calculation unit 34 corrects the torque command value To.

[0088] In this embodiment, as shown in Figure 11, the current command value calculation unit 34 corrects the torque command value To based on the detected or estimated torque of the AC rotating electric machine, and calculates the current command value based on the corrected torque command value Tocrr.

[0089] The current command value calculation unit 34 calculates the estimated torque value Test based on the current detection values ​​Idr and Iqr of the d axis and q axis, using the following equation, which is the same as equation (8). The method for calculating the estimated torque value is not particularly limited, and it may be calculated using other methods, such as calculating the estimated torque value using power / rotational angular velocity.

number

[0090] Alternatively, if a torque sensor is provided to detect the torque output from the rotor's rotation axis, the current command value calculation unit 34 may calculate the detected torque value Tr based on the output signal of the torque sensor, instead of the estimated torque value Test.

[0091] Then, as shown in the following equation, the current command value calculation unit 34 calculates a torque correction value Ta based on the deviation ΔT between the torque command value To and the estimated torque value Test, corrects the torque command value To using the torque correction value Ta, and calculates the corrected torque command value Tocrr. The current command value calculation unit 34 performs feedback control such as integral control, proportional-integral control, and proportional-integral-derivative control on the deviation ΔT to calculate the torque correction value Ta, adds the torque correction value Ta to the torque command value To, and calculates the corrected torque command value Tocrr.

number

[0092] The current command value calculation unit 34 then refers to the torque command value To, the speed-voltage ratio Rωv, and the current command value setting data, which has a pre-set relationship with the current command value, and calculates the corrected torque command value Tocrr, which is obtained by correcting the current torque command value To, and the current command value corresponding to the corrected speed-voltage ratio Rωvcrr. Except for the fact that the corrected torque command value Tocrr is used, this is the same as in Embodiment 1, so the explanation will be omitted.

[0093] With this configuration, by using the current command value setting data that was set without torque error, and by referring to the current command value setting data and calculating the current command value corresponding to the corrected torque command value Tocrr, even if a torque error occurs due to error factors, the estimated torque value Test can be brought closer to the torque command value To, and the desired torque can be obtained from the AC rotating electric machine.

[0094] 4. Embodiment 4 The AC rotating electric machine 2 and control device 1 according to Embodiment 3 will now be described. The same components as those in Embodiments 1, 2, or 3 described above will be omitted from the description. The basic configuration of the AC rotating electric machine 2 and control device 1 according to this embodiment is the same as that of Embodiments 1, 2, or 3, but it differs from Embodiments 1, 2, or 3 in that 1-pulse control is performed in a voltage saturation (overmodulation) state.

[0095] Similar to Embodiment 1, the current command value calculation unit 34 refers to modulation ratio command value setting data in which the torque command value To, the speed voltage ratio Rωv, and the modulation ratio command value Mo have a preset relationship, and calculates the current torque command value To and the modulation ratio command value Mo corresponding to the detected value Rωvr of the current speed voltage ratio. For example, map data is used as the modulation ratio command value setting data. In the present embodiment, as shown in FIG. 12 or FIG. 13, in the modulation ratio command value setting data, in the operation region of field-weakening control, the modulation ratio command value Mo is set to include 2×√3 / π (≒1.10) corresponding to one-pulse control. As shown in FIG. 12, in the operation region of field-weakening control, the modulation ratio command value Mo may be set to 1.10. Alternatively, as shown in FIG. 13, in the operation region of field-weakening control, in a region of relatively low torque and low speed, the modulation ratio command value Mo is set to 1.0 < Mo < 1.10, and in a region of relatively high torque and high speed, the modulation ratio command value Mo may be set to 1.10.

[0096] When the actual modulation ratio Mr falls within the determination range of the modulation ratio corresponding to one-pulse control, the voltage command value calculation unit 35 executes one-pulse control in which each switching element is turned on and off once during an AC cycle. The determination range is a range including 1.10, for example, set from 1.09 to 1.11. The control other than one-pulse control described in Embodiment 1 is referred to as normal control.

[0097] When executing one-pulse control, the voltage command value calculation unit 35 uses the following formula to calculate the phase θv of the voltage vector with respect to the q-axis based on the voltage command values Vdo and Vqo of the d-axis and q-axis, and based on the phase θv and the magnetic pole position θr, calculates the three-phase voltage command values Vuo, Vvo, and Vwo of a one-pulse rectangular wave with the phase adjusted. The amplitude of the one-pulse rectangular wave is made the same as the amplitude of the carrier wave.

Equation

[0098] Furthermore, as shown in Figure 12 or Figure 13, if the modulation rate command value Mo is set to a value smaller than the 1-pulse setting value (1.10 in this example), which is the setting value corresponding to 1-pulse control, and 1-pulse control is not being performed, and normal control is being performed, then after the modulation rate command value Mo becomes the 1-pulse setting value, the voltage command value calculation unit 35 terminates normal control and performs 1-pulse control if the actual modulation rate Mr falls within a determination range that includes the 1-pulse setting value.

[0099] When 1-pulse control is performed, the actual modulation rate Mr becomes the 1-pulse set value (1.10). However, since the system can switch from normal control to 1-pulse control when the actual modulation rate Mr approaches the 1-pulse set value, a sudden change in the actual modulation rate Mr can be prevented.

[0100] <Other embodiments> In the above embodiment, the case in which a three-phase winding is provided was described as an example. However, the number of phases of the winding may be set to any number, such as two phases or four phases, as long as there are multiple phases.

[0101] In the above embodiment, the case in which one set of three-phase windings and inverters is provided was described as an example. However, two or more sets of three-phase windings and inverters may be provided, and the same control as in each embodiment may be performed for each set of three-phase windings and inverters.

[0102] <Summary of the various aspects of this application> The various aspects of this application are summarized below as an appendix. (Note 1) A control device for an AC rotating electric machine having an armature winding, which controls the AC rotating electric machine via an inverter, A current command value calculation unit calculates a current command value based on the torque command value, the detected rotational speed of the AC rotating electric machine, and the DC voltage supplied to the inverter. A voltage command value calculation unit calculates a voltage command value to be applied to the armature winding based on the current command value, The inverter comprises a PWM control unit that controls the on / off state of a plurality of switching elements based on the voltage command value, The modulation rate is defined as a value corresponding to the ratio of the effective value of the voltage command value to the DC voltage. The current command value calculation unit calculates a detected value of the speed-voltage ratio, which is the ratio of the detected rotational speed to the DC voltage, calculates the actual modulation rate based on the voltage command value and the DC voltage, corrects the detected value of the speed-voltage ratio based on the deviation between the modulation rate command value and the actual modulation rate, and calculates the corrected speed-voltage ratio. A control device for an AC rotating electric machine that calculates the current command value corresponding to the current torque command value and the corrected speed-voltage ratio by referring to current command value setting data in which the relationship between the torque command value, the speed-voltage ratio, and the current command value is predetermined.

[0103] (Note 2) The current command value setting data includes: Assuming that basic control is performed, in the operating region where the induced voltage during basic control, which is the induced voltage generated in the armature winding according to the current flowing through the armature winding and the rotational speed, exceeds the DC voltage, a relationship is predetermined between the torque command value, the speed-voltage ratio, and the current command value that causes the AC rotating electric machine to output the torque of the torque command value while matching the induced voltage to the DC voltage under the conditions of the torque command value and the speed-voltage ratio. In the operating range where the induced voltage during the basic control does not exceed the DC voltage, the control device for an AC rotating electric machine described in Appendix 1 has a predetermined relationship between the torque command value, the speed-voltage ratio, and the current command value obtained by the basic control that causes the AC rotating electric machine to output the torque of the torque command value under the conditions of the torque command value and the speed-voltage ratio.

[0104] (Note 3) The control device for an AC rotating electric machine as described in Appendix 2, wherein the basic control is a maximum torque / current control which sets the current command value that minimizes the current used to output the torque of the torque command value, or an Id=0 control which sets the d-axis current to 0 while setting the current command value that outputs the torque of the torque command value.

[0105] (Note 4) The speed-voltage ratio is the ratio obtained by dividing the rotational speed by the DC voltage. If the actual modulation rate is smaller than the modulation rate command value, the current command value calculation unit changes the correction value for the detected speed voltage ratio so that the corrected speed voltage ratio decreases. A control device for an AC rotating electric machine according to any one of the appendices 1 to 3, wherein if the actual modulation rate is greater than the modulation rate command value, the correction value is changed so that the corrected speed-voltage ratio increases.

[0106] (Note 5) The current command value calculation unit calculates a correction value for the detected speed voltage ratio by feedback control based on the deviation between the modulation rate command value and the actual modulation rate, as described in any one of the appendices 1 to 4.

[0107] (Note 6) The control device for an AC rotating electric machine as described in Appendix 5, wherein the current command value calculation unit stops the operation of the integrator included in the feedback control or initializes the integral value when the condition for the detected value of the rotational speed, or the condition for the modulation rate command value or the actual modulation rate is met.

[0108] (Note 7) The current command value calculation unit sets the correction amount for the detected speed-voltage ratio to 0 when the condition for the detected rotation speed, or the condition for the modulation rate command value or the actual modulation rate is met, and calculates the detected speed-voltage ratio as the corrected speed-voltage ratio, according to any one of the appendices 1 to 6.

[0109] (Note 8) The current command value calculation unit is a control device for an AC rotating electric machine according to any one of the following appendices 1 to 7, wherein the speed voltage ratio is a normalized speed voltage ratio obtained by normalizing the speed voltage ratio with one or more of the modulation rate command value, the reference value of the DC voltage, and the reference value of the modulation rate.

[0110] (Note 9) The control device for an AC rotating electric machine according to any one of the appendices 1 to 8, wherein the current command value calculation unit corrects the torque command value based on the torque of the AC rotating electric machine detected or estimated, and calculates the current command value based on the corrected torque command value.

[0111] (Note 10) The control device for an AC rotating electric machine according to any one of the appendices 1 to 9, wherein the current command value calculation unit changes the modulation rate command value based on at least one of the detected rotational speed, the torque command value, the detected or estimated torque value of the AC rotating electric machine, the current command value, the detected current value, and the actual modulation rate.

[0112] (Note 11) The control device for an AC rotating electric machine according to any one of the appendices 1 to 10, wherein the voltage command value calculation unit executes the one-pulse control, which turns each switching element on and off once during the AC cycle, when the actual modulation rate falls within the determination range corresponding to one-pulse control.

[0113] (Note 12) The control device for an AC rotating electric machine according to any one of the appendices 1 to 10, wherein the voltage command value calculation unit executes the one-pulse control, which turns each switching element on and off once during the AC cycle, when the actual modulation rate falls within a determination range that includes the one-pulse setting value after the modulation rate command value has become a one-pulse setting value which is a set value corresponding to one-pulse control.

[0114] While this application describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but are applicable individually or in various combinations to the embodiments. Accordingly, countless variations not illustrated are envisioned within the scope of the art disclosed herein. For example, these include modifying, adding, or omitting at least one component, or even extracting at least one component and combining it with a component from another embodiment. [Explanation of Symbols]

[0115] 1: Control device for AC rotating electric machine, 2: AC rotating electric machine, 20: Inverter, 34: Current command value calculation unit, 35: Voltage command value calculation unit, 36: PWM control unit, Kr: Correction value, Mo: Modulation rate command value, Mr: Actual modulation rate, Rωv: Speed-to-voltage ratio, Rωvr: Detected value of speed-to-voltage ratio, Rωvcrr: Corrected speed-to-voltage ratio, Rωvnrm: Normalized speed-to-voltage ratio, Rωvrcrr: Speed-to-voltage ratio, To: Torque command value, Tocrr: Corrected torque command value, Vdc: DC voltage, Ve: Effective value of voltage command value, ω: Rotational speed, ωr: Detected value of rotational speed

Claims

1. A control device for an AC rotating electric machine having an armature winding, which controls the AC rotating electric machine via an inverter, A current command value calculation unit calculates a current command value based on the torque command value, the detected rotational speed of the AC rotating electric machine, and the DC voltage supplied to the inverter. A voltage command value calculation unit calculates a voltage command value to be applied to the armature winding based on the current command value, The inverter comprises a PWM control unit that controls the on / off state of a plurality of switching elements based on the voltage command value, The modulation rate is defined as a value corresponding to the ratio of the effective value of the voltage command value to the DC voltage. The current command value calculation unit calculates a detected value of the speed-voltage ratio, which is the ratio of the detected rotational speed to the DC voltage, calculates the actual modulation rate based on the voltage command value and the DC voltage, corrects the detected value of the speed-voltage ratio based on the deviation between the modulation rate command value and the actual modulation rate, and calculates the corrected speed-voltage ratio. A control device for an AC rotating electric machine that calculates the current torque value and the current command value corresponding to the corrected speed-voltage ratio by referring to current command value setting data in which the relationship between the torque command value, the speed-voltage ratio, and the current command value is predetermined.

2. The current command value setting data includes: Assuming that basic control is performed, in the operating region where the induced voltage during basic control, which is the induced voltage generated in the armature winding according to the current flowing through the armature winding and the rotational speed, exceeds the DC voltage, a relationship is predetermined between the torque command value, the speed-voltage ratio, and the current command value that causes the AC rotating electric machine to output the torque of the torque command value while matching the induced voltage to the DC voltage under the conditions of the torque command value and the speed-voltage ratio. A control device for an AC rotating electric machine according to claim 1, wherein in an operating region where the induced voltage during the basic control does not exceed the DC voltage, a relationship is predetermined between the torque command value, the speed-voltage ratio, and the current command value by the basic control that causes the AC rotating electric machine to output the torque of the torque command value under the conditions of the torque command value and the speed-voltage ratio.

3. The control device for an AC rotating electric machine according to claim 2, wherein the basic control is a maximum torque / current control which sets the current command value that minimizes the current used to output the torque of the torque command value, or an Id=0 control which sets the current command value that outputs the torque of the torque command value while setting the d-axis current to 0.

4. The speed-voltage ratio is the ratio obtained by dividing the rotational speed by the DC voltage. The current command value calculation unit, when the actual modulation rate is smaller than the modulation rate command value, changes the correction value for the detected speed voltage ratio so that the corrected speed voltage ratio decreases. The control device for an AC rotating electric machine according to claim 1, wherein if the actual modulation rate is greater than the modulation rate command value, the correction value is changed so that the corrected speed-voltage ratio increases.

5. The control device for an AC rotating electric machine according to claim 1, wherein the current command value calculation unit calculates a correction value for the detected value of the speed voltage ratio by feedback control based on the deviation between the modulation rate command value and the actual modulation rate.

6. The control device for an AC rotating electric machine according to claim 5, wherein the current command value calculation unit stops the operation of the integrator included in the feedback control or initializes the integral value when the condition for the detected value of the rotational speed, or the condition for the modulation rate command value or the actual modulation rate is met.

7. The control device for an AC rotating electric machine according to claim 1, wherein the current command value calculation unit sets the correction amount for the detected speed-voltage ratio to 0 when the condition for the detected rotation speed, or the condition for the modulation rate command value or the actual modulation rate is met, and calculates the detected speed-voltage ratio as the corrected speed-voltage ratio.

8. The control device for an AC rotating electric machine according to claim 1, wherein the current command value calculation unit uses a normalized speed voltage ratio obtained by normalizing the speed voltage ratio with one or more of the modulation rate command value, the reference value of the DC voltage, and the reference value of the modulation rate as the speed voltage ratio.

9. The control device for an AC rotating electric machine according to claim 1, wherein the current command value calculation unit corrects the torque command value based on the torque of the AC rotating electric machine detected or estimated, and calculates the current command value based on the corrected torque command value.

10. The control device for an AC rotating electric machine according to claim 1, wherein the current command value calculation unit changes the modulation rate command value based on at least one of the detected value of the rotational speed, the torque command value, the detected or estimated value of the torque of the AC rotating electric machine, the current command value, the detected current value, and the actual modulation rate.

11. The control device for an AC rotating electric machine according to claim 1, wherein the voltage command value calculation unit executes the one-pulse control, which turns each switching element on and off once during the AC cycle, when the actual modulation rate falls within a determination range corresponding to one-pulse control.

12. The control device for an AC rotating electric machine according to claim 1, wherein the voltage command value calculation unit executes the one-pulse control, which turns each switching element on and off once during the AC cycle, when the actual modulation rate falls within a determination range that includes the one-pulse setting value after the modulation rate command value has become a one-pulse setting value which is a set value corresponding to one-pulse control.

Images