Control device for AC motors and electric vehicles equipped therewith, and electric aircraft

Abstract

To provide an AC motor control device capable of stabilizing a multipolarized AC motor and performing vector control.SOLUTION: The present invention includes a control device 2 that controls an AC motor 1 via an inverter 3 on the basis of angular information from a position sensor 5. The position sensor 5 is set in such a way that the number of pole pairs of the ratio AC motor 1 is equal to an integral multiple of a double axial angle X of the position sensor 5. The control device 2 includes an electric angle phase calculation unit 22 that multiplies angle information detected by the position sensor 5, by an integer, and converts the resultant information to electric angle phase information, an electric angle rotational speed calculation unit 23 that calculates an electric angle rotational speed on the basis of the electric angle phase information calculated by the electric angle phase calculation unit 22, and a vector control unit 21 that calculates a voltage command value to be outputted to the inverter 3 on the basis of the electric angle phase information calculated by the electric angle phase calculation unit 22 and the electric angle rotational speed calculated by the electric angle rotational speed calculation unit 23.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a control device for an alternating current motor that drives an alternating current motor, an electric vehicle equipped with the same, and an electric aircraft.

Background Art

[0002] In recent years, due to the increasing demand for energy conservation, control devices for alternating current motors that drive alternating current motors have been applied to a wide range of applications such as home appliances, infrastructure, and industrial equipment. In particular, in electric vehicles, in order to expand the interior space and battery installation space, research on in-wheel motors that arrange an alternating current motor inside the wheel has been progressing. In-wheel motors have strong requirements for miniaturization and high output density, and thus have a multi-polar design.

[0003] In addition, as one of the methods of a control device for driving an alternating current motor, there is a configuration that uses a resolver as a means for detecting the rotational position and rotational speed of the alternating current motor. The resolver is attached to the rotating shaft and rotates together with the rotating shaft, and is a sensor that converts the mechanical angle of the rotating shaft into an electrical signal using electromagnetic induction. It has excellent environmental resistance and is being applied in a wide range of applications.

[0004] However, due to the principle of using electromagnetic induction, the resolver has an upper limit on the number of poles it can handle. The maximum number of poles of a general resolver is about 10 poles. Also, it is known that noise proportional to the rotational speed of the alternating current motor is generated in the angle signal due to mounting errors or the like.

[0005] As a technique for removing such noise proportional to the rotational speed of the alternating current motor, for example, the technique described in Patent Document 1 has been proposed. In Patent Document 1, by using a filter that attenuates specific frequency components, the noise included in the angle signal is suppressed.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] The number of poles in a multi-pole AC motor is greater than the maximum number of poles in a typical resolver. Therefore, when using a resolver with a multi-pole AC motor, a resolver with fewer poles than the AC motor's poles must be used. In other words, there is a problem in that the phase difference between the electrical angle phase per rotation of the AC motor's mechanical angle and the angle information of the resolver becomes large.

[0008] While the technology described in Patent Document 1 can suppress noise caused by the resolver, it does not consider the issue of increased electrical angular phase difference when a resolver with fewer poles is applied to a multi-pole AC motor. Therefore, it has been difficult to stably vector control a multi-pole AC motor.

[0009] The object of the present invention is to provide a control device for an AC motor that can stably perform vector control of a multi-pole AC motor. [Means for solving the problem]

[0010] To achieve the above objective, the present invention provides an AC motor control device that controls the AC motor via an inverter based on angular information from a position sensor that detects the angular position of the AC motor, wherein the position sensor is set so that the ratio of the number of pole pairs of the AC motor to the axis multiplier X of the position sensor is an integer multiple, and the control device includes an electrical angular phase calculation unit that multiplies the angular information of the AC motor detected by the position sensor by the integer multiple and converts it into electrical angular phase information of the AC motor, and the electrical angular rotation number of the AC motor based on the electrical angular phase information of the AC motor calculated by the electrical angular phase calculation unit and control phase Calculate Electrical angular phase and rotation speed calculation unit and the electrical angular phase information of the AC motor calculated by the electrical angular phase calculation unit, and the Electrical angular phase and rotation speed calculation unitThe electrical angular rotations of the AC motor calculated by and control phase The system comprises a vector control unit that calculates a voltage command value to be output to the inverter based on the above, The electrical angular phase / rotation speed calculation unit includes a phase difference calculation unit that calculates an electrical angular phase difference which is the difference between the electrical angular phase information and the control phase; a filter processing unit that reduces the frequency component obtained by integer multiplying the axis multiplier X to the mechanical rotation speed of the AC motor based on the electrical angular phase difference calculated by the phase difference calculation unit, the number of pole pairs of the AC motor and the axis double angle X information of the position sensor and the electrical angular rotation speed of the AC motor; a speed estimation unit that estimates the electrical angular rotation speed of the AC motor based on either the electrical angular phase difference from the phase difference calculation unit or the electrical angular phase difference filtered by the filter processing unit; a phase difference switching unit that switches whether the electrical angular phase difference input to the speed estimation unit is the electrical angular phase difference from the phase difference calculation unit or the electrical angular phase difference filtered by the filter processing unit, according to the rotation speed of the AC motor; and a control phase calculation unit that calculates the control phase used in the vector control unit based on the electrical angular rotation speed of the AC motor calculated by the speed estimation unit. It is characterized by having the following features. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a control device for an AC motor that can stably perform vector control of a multi-pole AC motor. [Brief explanation of the drawing]

[0012] [Figure 1] This is a block diagram showing the overall configuration of the drive unit for an AC motor according to Embodiment 1 of the present invention. [Figure 2] This diagram shows the relationship between the angle information from the position sensor and the electrical angle of the AC motor. [Figure 3] This figure shows the relationship between the angle information of the position sensor and the electrical angle of the AC motor in the comparative example. [Figure 4A] This figure shows the relationship between the angle information from a position sensor containing noise components and the electrical angle of an AC motor. [Figure 4B] This figure compares the noise component of one rotation of the position sensor phase information with the noise component after calculation by the electrical angular phase calculation unit 22. [Figure 5] This is a block diagram showing the overall configuration of the drive unit for an AC motor according to Embodiment 2 of the present invention. [Figure 6] Figure 5 is a detailed configuration diagram of the electrical angular phase and rotational speed calculation unit. [Figure 7] This figure shows the waveform of the electrical angle phase difference 241A calculated by the phase difference calculation unit 241. [Figure 8] This figure shows the waveform of the electrical angular phase difference of 242A after filtering. [Figure 9] This is a detailed configuration diagram of the electrical angular phase and rotational speed calculation unit according to Embodiment 3 of the present invention. [Figure 10] This is a schematic diagram of an electric vehicle according to Embodiment 4 of the present invention. [Figure 11]This is a schematic diagram of an electric aircraft according to Example 5 of the present invention.

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. For the same elements, the same reference numerals are generally used in all the drawings. Also, for parts having the same function, the description will be omitted. Note that the configurations described below are merely examples, and it is not intended that the embodiments according to the present invention be limited to the following specific forms.

Example

[0014] Example 1 of the present invention will be described with reference to FIGS. 1 to 11. In Example 1, an example of driving an alternating current motor 1 will be used for the description.

[0015] 〔Overall Configuration〕 FIG. 1 is a block diagram showing the overall configuration diagram of a driving device for an alternating current motor according to Example 1 of the present invention.

[0016] As shown in FIG. 1, the control device 2 includes a current detection circuit 4 that detects the current flowing through the alternating current motor 1, and based on the information of a position sensor 5 that detects the rotational position of the alternating current motor 1, a vector control unit 21 calculates a voltage command value. The inverter 3 supplies alternating current power to the alternating current motor 1 based on the voltage command value calculated by the vector control unit 21. Also, the control device 2 multiplies the rotational phase information detected by the position sensor 5, which will be described later, by an integer multiple and converts it into electrical angle phase information 22A of the alternating current motor 1, and includes an electrical angle phase calculation unit 22 that calculates the electrical angle rotation speed of the alternating current motor 1 based on the electrical angle phase information 22A calculated by the electrical angle phase calculation unit 22. The vector control unit 21 outputs a voltage command value to the inverter 3 based on the electrical angle phase information 22A calculated by the electrical angle phase calculation unit 22 and the electrical angle rotation speed 23A calculated by the electrical angle rotation speed calculation unit 23. Note that the vector control unit 21 can be realized by using general vector control and does not specify the control method.

[0017] [Challenges when using multi-pole AC motors] As mentioned above, one method for miniaturizing and increasing the output of AC motor 1 is to design it with multiple poles. On the other hand, if a resolver that utilizes electromagnetic induction is applied as a position sensor for AC motor 1, there is an upper limit to the number of poles that can be handled, in principle. The maximum number of poles for a typical resolver is about 10, and the number of poles in a multi-pole AC motor is greater than the number of poles in a resolver.

[0018] Here, the value obtained by dividing the number of poles of an AC motor by 2 is called the pole pair number PP. The pole pair number is the number of pairs of poles, such as the north pole and south pole of a magnet. Furthermore, the rotational speed obtained by multiplying the mechanical rotational speed ωr of the AC motor by the pole pair number ωr × PP is called the electrical angular rotational speed, and vector control is calculated based on the electrical angular rotational speed.

[0019] Furthermore, for resolvers, which are position sensors, the ratio of how many rotations of phase are output when an AC motor mechanically rotates once is called the axis double angle X. For example, when X=2, where two rotations of phase are output when one rotation occurs, it is called 2X.

[0020] As mentioned above, there is an upper limit to the number of poles in a resolver, and consequently, there is also an upper limit to the shaft double angle X of the resolver. Therefore, when the AC motor 1 is multi-pole, the number of pole pairs PP becomes larger than the shaft double angle X. An example is shown in Figure 2.

[0021] Figure 2 shows the relationship between the angle information from the position sensor and the electrical angle of the AC motor. Figure 2 shows an example of the waveform of the angle information when the axis double angle of the position sensor and the number of pole pairs of the AC motor are multiplied by 5. As shown in Figure 2, if the mechanical rotation angle of the AC motor is taken as the horizontal axis and the angle information from the position sensor is taken as the vertical axis, then as shown in the upper figure, the electrical angle of the motor rotates by (number of pole pairs PP / axis double angle X) while the angle information of the position sensor rotates once from 0 to 360 degrees. In the example in Figure 2, an example is shown where (number of pole pairs PP / axis double angle X) rotates 5 times.

[0022] [Configuration of Example 1] In Example 1, the AC motor 1 and the resolver (position sensor 5) are configured such that the ratio of the number of pole pairs PP of the AC motor 1 to the axis double angle X of the resolver (position sensor 5), i.e., the ratio of the number of pole pairs PP of the AC motor 1 to the axis double angle X (the ratio of the number of pole pairs PP of the AC motor 1 to the axis double angle X), is an integer multiple. In other words, the AC motor 1 and the resolver (position sensor 5) are configured such that (number of pole pairs PP / axis double angle X) = N (N: integer).

[0023] This makes it possible to calculate the electrical angular phase information 22A of the AC motor 1 in a simple configuration by multiplying the angle information 5A output from the position sensor 5 by an N (integer) in the electrical angular phase calculation unit 22 to obtain information from 0 to 360 degrees.

[0024] As an example of a simplified calculation, if the angle information from a position sensor is converted using AD conversion and taken as a fixed-point number, the angle information can be multiplied by N while remaining a fixed-point number, enabling high-speed calculations.

[0025] A comparative example will be explained using Figure 3. Figure 3 is a diagram showing the relationship between the angle information of the position sensor and the electrical angle of the AC motor in the comparative example. Figure 3 shows an example of the waveform of the angle information when the angle information of the position sensor, the axis double angle of the position sensor, and the number of pole pairs of the AC motor are multiplied by 5.5.

[0026] As shown in Figure 3, when the (pole logarithm PP / axis multiplier X) is not an integer multiple, such as 5.5 times, it is necessary to consider the multiplier after the decimal point. For example, if the AD-converted value of the position sensor angle information is taken as a fixed-point number, in order to avoid the loss of 0.5 decimal points due to the 5.5 multiplier, it is necessary to multiply by a value such as 2.5 * 2^10 including the bit shift, and then divide by the bit shift amount of 2^10. Therefore, the control device needs to perform extra calculations to account for the bit shift.

[0027] Therefore, in Example 1, the AC motor 1 and the position sensor 5 are configured such that (pole-logarithm PP / axis-double angle X) = N (N: integer).

[0028] As shown in Figure 1, the control device 2 of Embodiment 1 includes an electrical angular phase calculation unit 22 that multiplies the angle information 5A of the AC motor 1 detected by the position sensor 5 by an integer multiple and converts it into electrical angular phase information 22A of the AC motor 1; an electrical angular rotation speed calculation unit 23 that calculates the electrical angular rotation speed 23A of the AC motor 1 based on the electrical angular phase information 22A of the AC motor 1 calculated by the electrical angular phase calculation unit 22; and a vector control unit 21 that calculates a voltage command value to be output to the inverter 3 based on the electrical angular phase information 22A of the AC motor 1 calculated by the electrical angular phase calculation unit 22 and the electrical angular rotation speed 23A of the AC motor 1 calculated by the electrical angular rotation speed calculation unit 23. The electrical angular rotation speed calculation unit 23 can calculate the rotation speed using a general configuration such as a phase differentiation configuration or a proportional-integral control configuration.

[0029] According to Example 1, by configuring the system as described above, the multi-pole AC motor 1 can be stably vector-controlled. [Examples]

[0030] Next, Example 2 will be described using Figures 4 to 8. When a resolver is used as a position sensor, it is known that, due to mounting errors and other factors, primary, secondary, and other noise components are generated during the 360-degree rotation of the resolver's angle information.

[0031] During one mechanical rotation of an AC motor, the resolver outputs a phase angle equal to the axis multiplier X rotations. Therefore, the frequency of the first-order noise component is the mechanical rotation speed ωr × axis multiplier X, where ωr is the mechanical rotation speed of AC motor 1. Similarly, the Nth-order noise component is the mechanical rotation speed ωr × axis multiplier X × N.

[0032] Figure 4A shows the relationship between the angle information of the position sensor, which includes noise components, and the electrical angle of the AC motor. Figure 4B compares the noise component for one rotation of the position sensor phase information with the noise component after calculation by the electrical angle phase calculation unit 22. Figures 4A and 4B show that a first-order noise component occurs in the position sensor angle information of the resolver in a configuration where (pole-to-pole number PP / axis-double angle X) = 5 times.

[0033] As shown in the upper part of Figure 4A, in the case of a first-order noise component, one angular error occurs relative to the dotted line noise-free angular information while the resolver's angular information completes one rotation. In other words, as shown in the upper part of Figure 4B, one increase or decrease in angular error occurs while the resolver's angular information completes one rotation. As a result, when the electrical angular phase calculation unit 22 multiplies the resolver's angular information by (number of pole pairs PP / axis double angle X) = 5, the aforementioned first-order noise component is superimposed on the electrical angular phase information 22A of the AC motor 1.

[0034] Furthermore, as shown in the lower part of Figure 4A, noise components are also generated in the electrical angle of the AC motor 1. If the electrical angle phase calculation unit 22 multiplies the resolver's angle information by (number of pole pairs PP / axis double angle X) = 5, the noise component becomes 5 times larger than the original noise component, as shown in the lower part of Figure 4B. When the electrical angle rotation speed is calculated using position sensor angle information containing such noise components and vector control is performed, current pulsation occurs in the AC motor 1, leading to the problem of unstable control.

[0035] Therefore, in Example 2, filtering is performed to remove noise components. Figure 5 is a block diagram showing the overall configuration of the AC motor drive device according to Example 2 of the present invention. Figure 6 is a detailed configuration diagram of the electrical angular phase and rotational speed calculation unit of Figure 5. Components common to Example 1 are denoted by the same reference numerals, and their detailed explanations are omitted.

[0036] As shown in Figure 5, the control device 2 of Embodiment 2 includes an electrical angular phase / rotation speed calculation unit 24. The electrical angular phase / rotation speed calculation unit 24 calculates the electrical angular rotation speed 24A and control phase 24B of the AC motor 1 based on the electrical angular phase information 22A of the AC motor 1 calculated by the electrical angular phase calculation unit 22. In addition to the function of the electrical angular rotation speed calculation unit 23, which calculates the electrical angular rotation speed of the AC motor 1 based on the electrical angular phase information 22A of the AC motor 1, the electrical angular phase / rotation speed calculation unit 24 also has the function of calculating the control phase 24B. In other words, the electrical angular phase / rotation speed calculation unit 24 is an electrical angular rotation speed calculation unit 23 with the function of calculating the control phase 24B.

[0037] As shown in Figure 6, the electrical angular phase / rotation speed calculation unit 24 includes a phase difference calculation unit 241, a filter processing unit 242, a speed estimation unit 243, a motor / position sensor information unit 244, and a control phase calculation unit 245. The motor / position sensor information unit 244 stores information on the number of pole pairs PP of the AC motor 1 and the axis double angle X of the resolver.

[0038] The electrical angular phase / rotation speed calculation unit 24 receives electrical angular phase information 22A and control phase 24B as input and calculates the electrical angular phase difference 241A, which is the difference between the electrical angular phase information 22A and the control phase 24B. Figure 7 shows the waveform of the electrical angular phase difference 241A calculated by the phase difference calculation unit 241. As shown in Figure 7, the electrical angular phase difference 241A calculated by the phase difference calculation unit 241 increases or decreases once for every rotation of the angle information of the resolver, which is a position sensor. In other words, the frequency of the noise component included in the electrical angular phase difference 241A is the frequency component obtained by multiplying the mechanical rotation speed ωr by the axis multiplier X, where ωr is the mechanical rotation speed of the AC motor.

[0039] Therefore, the filter processing unit 242 performs a filter process to reduce the frequency component obtained by multiplying the mechanical rotation speed ωr of the AC motor 1 by the axis double angle X (mechanical rotation speed ωr × axis double angle X) based on the electrical angular phase difference 241A, the pole pair number PP of the AC motor 1 and the resolver axis double angle X information output from the motor / position sensor information unit 244, and the electrical angular rotation speed 24A of the AC motor 1.

[0040] Here, the mechanical rotational speed ωr is obtained by dividing the electrical angular rotational speed of AC motor 1 (24A) by the number of pole pairs (PP) of the motor. An example of filtering is a configuration in which the aforementioned frequency components are reduced by a notch filter.

[0041] Figure 8 shows the waveform of the electrical angular phase difference 242A after filtering. As shown in Figure 8, the filtering unit 242 suppresses the noise components that were included in the electrical angular phase difference 241A in the filtered electrical angular phase difference 242A before outputting it.

[0042] In this way, the speed estimation unit 243 calculates the electrical angular rotation speed 24A of the AC motor 1 based on the electrical angular phase difference 242A after filtering, in which noise components have been suppressed, and the control phase calculation unit 245 calculates the control phase 24B used by the vector control unit 21 based on the electrical angular rotation speed 24A of the AC motor 1. The speed estimation unit 243 can perform calculations using general configurations such as proportional and integral control calculations, and the control phase calculation unit 245 can perform calculations using integral calculations, etc.

[0043] The configuration described so far assumes that a first-order noise component occurs in the resolver. However, if the resolver generates second-order, third-order, or other N-order noise, it is possible to suppress the N-order noise component by multiplying the axis doubling angle X of the position sensor axis doubling information by N (an integer multiple).

[0044] As described above, in Embodiment 2, the electrical angular rotation speed 24A and control phase 24B of the AC motor 1 are calculated by suppressing noise components included in the angle information of the position sensor, and the AC motor is controlled by vector control 21 based on these values. This makes it possible to suppress current pulsation caused by the inclusion of noise components and stabilize the vector control. [Examples]

[0045] Next, Example 3 will be described using Figure 9. The effect of electrical angular phase error is also significant in the region where the rotational speed of the AC motor 1 is high. As shown in Figure 7, if first-order noise occurs in the electrical angular phase difference for each rotation of the position sensor phase information, even with the same ratio of angular error, the absolute value of the rotational speed fluctuation increases as the rotational speed of the AC motor 1 increases.

[0046] For example, in a configuration where (number of pole pairs PP / axis double angle X) = 5 times, suppose the resolver's angular error contains a 2% error, and this effect is reflected in the rotational speed. In this case, the noise component in the electrical angular phase calculation unit 22 becomes 5 times, resulting in a 10% error that is reflected in the rotational speed. Therefore, at 1 Hz, the error is 1 Hz ± 0.1 Hz, but at 100 Hz, it becomes 110 Hz, and at 100 Hz, the absolute value cannot be ignored. In other words, in the low rotational speed range of the AC motor 1, the effect of the angular error on the absolute value of the rotational speed is small, but as the rotational speed of the AC motor 1 increases, the effect of the angular error on the absolute value of the rotational speed becomes larger.

[0047] The means for solving this will be described. Figure 9 is a detailed configuration diagram of the electrical angular phase / rotation speed calculation unit according to Embodiment 3 of the present invention. Components common to Embodiments 1 and 2 are denoted by the same reference numerals, and their detailed descriptions are omitted. Embodiment 3 includes a phase difference switching unit 246 in addition to the configuration of Embodiment 2. The phase difference switching unit 246 switches between using the electrical angular phase difference 242A filtered by the filter processing unit 242, or using the electrical angular phase difference 241A output from the phase difference calculation unit 241 as is.

[0048] In this phase difference switching unit 246, if the rotational speed of the AC motor 1 is lower than a predetermined value, the electrical angle phase difference 241A of the phase difference calculation unit is selected, and if the rotational speed of the AC motor 1 is higher than a predetermined value, the electrical angle phase difference 242A filtered by the filter processing unit 242 is selected.

[0049] According to Embodiment 3, when the rotational speed of the AC motor 1 is lower than a predetermined value, vector control can be performed using the electrical angular phase difference excluding the effect of the filter, thereby reducing the computational load on the control device 2.

[0050] Furthermore, in order to suppress fluctuations during switching, the phase difference switching unit 246 can also be configured to have predetermined lower and upper limits for the rotational speed of the AC motor 1. In this configuration, if the rotational speed of the AC motor 1 is lower than the predetermined lower limit, the electrical angle phase difference of the phase difference calculation unit 241 is selected, and if the rotational speed of the AC motor 1 is higher than the predetermined upper limit, the electrical angle phase difference filtered by the filter processing unit 242 is selected. Moreover, when the rotational speed of the AC motor 1 is between the predetermined lower limit and the predetermined upper limit, the phase difference switching unit 246 outputs the electrical angle phase difference 241A output from the phase difference calculation unit 241 and the filtered electrical angle phase difference 242A output from the filter processing unit in a tapered shape according to the ratio of the difference between the predetermined lower limit and the rotational speed of the AC motor 1 and the difference between the predetermined lower limit and the predetermined upper limit.

[0051] Specifically, the electrical angular phase difference output 246A of the phase difference switching unit 246 is configured to output "electrical angular phase difference output 246A = (1-d) × electrical angular phase difference 241A + d × electrical angular phase difference 242A" using the ratio d = Δωlow / ΔωHL between the difference Δωlow between the rotational speed of the AC motor 1 and a predetermined lower limit, and the difference ΔωHL from the predetermined lower limit to a predetermined upper limit. This makes it possible to reduce the shock when the electrical angular phase difference is switched by the phase difference switching unit 246. [Examples]

[0052] Next, Example 4 will be described using Figure 10. Figure 10 is a schematic diagram of an electric vehicle according to Example 4 of the present invention.

[0053] As shown in Figure 10, the electric vehicle 100 is equipped with in-wheel motors 101a and 101b, each with an AC motor 1 positioned on the wheel. Since the in-wheel motors 101a and 101b eliminate the need for a motor on the vehicle body side for wheel drive, it is possible to increase the interior space and battery installation space. Furthermore, one of the configurations from Embodiments 1 to 3 is used as the control device 2 for the AC motor 1.

[0054] According to Example 4, even for AC motors that have been made multi-pole to achieve miniaturization and high power density, vector control can be performed using resolvers with a small number of poles. Therefore, it is possible to construct a control configuration at low cost without using dedicated position sensors that support multiple poles. [Examples]

[0055] Next, Example 5 will be described using Figure 11. Figure 11 is a schematic diagram of an electric aircraft according to Example 5 of the present invention.

[0056] As shown in Figure 11, the electric aircraft 110 is equipped with AC motors 1 that drive the propulsion fans 111a and 111b. Furthermore, one of the configurations from Embodiments 1 to 3 is used as the control device 2 for the AC motors 1.

[0057] According to Example 5, using a small, high-power-density AC motor makes it possible to improve the energy efficiency of a jet engine and reduce CO2 emissions. Furthermore, even for multi-pole AC motors designed for miniaturization and high power density, vector control can be performed using a resolver with a small number of poles. This makes it possible to construct a highly reliable and stable control configuration at low cost using a resolver with high environmental resistance in harsh environments such as high altitudes and environments with a lot of vibration from fan operation.

[0058] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. For example, the embodiments described above are described in detail for the purpose of explaining the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations. [Explanation of Symbols]

[0059] 1...AC motor, 2...Control device, 3...Inverter, 4...Current detection circuit, 5...Position sensor, 5A...Angle information, 21...Vector control unit, 22...Electric angular phase calculation unit, 22A...Electric angular phase information, 23...Electric angular rotation speed calculation unit, 23A...Electric angular rotation speed, 24...Electric angular phase / rotation speed calculation unit, 24A...Electric angular rotation speed, 24B...Control phase, 100...Electric vehicle, 101a,101b...In-wheel motor, 110...Electric aircraft, 111a,111b...Propulsion fan, 241...Phase difference calculation unit, 241A...Electric angular phase difference, 242...Filter processing unit, 242A...Electric angular phase difference, 243...Speed ​​estimation unit, 244...Motor / position sensor information unit, 245...Control phase calculation unit, 246...Phase difference switching unit, 246A...Electric angular phase difference output.

Claims

1. In an AC motor control device that controls the AC motor via an inverter based on angle information from a position sensor that detects the angular position of the AC motor, The position sensor is set such that the ratio of the number of pole pairs of the AC motor to the axis multiplier X of the position sensor is an integer multiple. The control device is An electrical angular phase calculation unit that multiplies the angle information of the AC motor detected by the position sensor by the integer multiple and converts it into electrical angular phase information of the AC motor, An electrical angular phase and rotation speed calculation unit calculates the electrical angular rotation speed and control phase of the AC motor based on the electrical angular phase information of the AC motor calculated by the electrical angular phase calculation unit, The system includes a vector control unit that calculates a voltage command value to be output to the inverter based on the electrical angular phase information of the AC motor calculated by the electrical angular phase calculation unit, and the electrical angular rotation speed and control phase of the AC motor calculated by the electrical angular phase and rotation speed calculation unit, The aforementioned electrical angular phase and rotation speed calculation unit is: A phase difference calculation unit calculates the electrical angular phase difference, which is the difference between the electrical angular phase information and the control phase. A filter processing unit reduces the frequency component obtained by an integer multiple of the axis double angle X to the mechanical rotation speed of the AC motor, based on the electrical angle phase difference calculated by the phase difference calculation unit, the number of pole pairs of the AC motor and the axis double angle X information of the position sensor, and the electrical angle rotation speed of the AC motor. A speed estimation unit that estimates the electrical angular rotation speed of the AC motor based on either the electrical angular phase difference from the phase difference calculation unit or the electrical angular phase difference filtered by the filter processing unit, A phase difference switching unit that switches the electrical angular phase difference input to the speed estimation unit according to the rotational speed of the AC motor, whether to use the electrical angular phase difference from the phase difference calculation unit or the electrical angular phase difference filtered by the filter processing unit, A control phase calculation unit calculates the control phase used in the vector control unit based on the electrical angular rotation speed of the AC motor calculated by the speed estimation unit, A control device for an AC motor, characterized by being equipped with the following features.

2. In claim 1, The control device for an AC motor is characterized in that the phase difference switching unit selects the electrical angle phase difference of the phase difference calculation unit when the rotational speed of the AC motor is lower than a predetermined value, and selects the electrical angle phase difference filtered by the filter processing unit when the rotational speed of the AC motor is higher than a predetermined value.

3. In claim 1, The phase difference switching unit includes a predetermined lower limit value for the rotational speed of the AC motor and a predetermined upper limit value set to a rotational speed higher than the predetermined lower limit value. If the rotational speed of the AC motor is lower than the predetermined lower limit, the electrical angle phase difference of the phase difference calculation unit is selected; if the rotational speed of the AC motor is higher than the predetermined upper limit, the electrical angle phase difference filtered by the filter processing unit is selected. A control device for an AC motor, characterized in that, when the rotational speed of the AC motor is between a predetermined lower limit and a predetermined upper limit, the device outputs an electrical angle phase difference output from the phase difference calculation unit and an electrical angle phase difference after filtering output from the filter processing unit in a tapered manner according to the ratio between the difference between the predetermined lower limit and the rotational speed of the AC motor and the difference between the predetermined lower limit and the predetermined upper limit.

4. In an electric vehicle equipped with an AC motor mounted on a wheel and a control device for the AC motor that controls the AC motor, An electric vehicle characterized by being equipped with a control device for an AC motor as described in any one of claims 1 to 3.

5. In an electric aircraft equipped with an AC motor in the propulsion fan and a control device for the AC motor that controls the AC motor, An electric aircraft characterized by being equipped with a control device for an AC motor as described in any one of claims 1 to 3.

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