Control device and control method for rotating electric machine

Abstract

When noise of a speed detector is to be removed using a variable notch filter, the present invention prevents interference between a phase delay in speed detection response and a phase delay in the filter in a low speed region and achieves a noise reduction effect with respect to a frequency component around a cut-off frequency in a high speed region. To this end, provided is a control device which is for a rotary electric machine and which outputs a voltage command to a power converter that supplies electric power to the rotary electric machine so as to control the power converter, said control device comprising: a speed detection unit that detects the rotation speed of the rotary electric machine and outputs the rotation speed as a rotation speed detection signal; a filter that, with the rotation speed detection signal as input, removes noise which is superimposed on the rotation speed detection signal and which is in a specific frequency band dependent on the rotation speed; a bandwidth setting unit that, with the rotation speed detection signal as input, sets the bandwidth of the cut-off frequency of the filter; and a voltage command calculation unit that calculates a voltage command on the basis of an output from the filter. The bandwidth setting unit sets a wider bandwidth in accordance with an increase in the rotation speed.

Description

[Technical Field]

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

[0002] A resolver is used to detect the rotational position and rotational speed of a rotating electrical machine. The resolver output signal contains noise proportional to the rotational speed due to installation errors. To attenuate this noise, a variable notch filter is used, which attenuates certain frequency components and adjusts the cutoff frequency.

[0003] Patent Document 1 discloses a technology that uses a variable notch filter whose cutoff frequency changes in proportion to the rotation speed in order to remove noise of frequency components proportional to the rotation speed that is superimposed on the position detection signal of a resolver. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6222834 Summary of the Invention [Problem to be solved by the invention]

[0005] In known techniques, including the technique disclosed in Patent Document 1, a variable notch filter is used to remove noise components proportional to the rotation speed, but this variable notch filter causes a phase lag in the output relative to the input, which interferes with the speed detection response of the speed detector, making it difficult to obtain the desired speed detection response.

[0006] Interference between the speed detection response and the phase delay of the filter does not occur if the speed detection response and the cutoff frequency (center frequency) of the filter are sufficiently far apart, but interference is likely to occur if the speed detection response and the cutoff frequency of the filter are close.

[0007] Generally, when noise from a speed detector is removed using a variable notch filter, the filter's cutoff frequency becomes higher than the speed detection response of the speed detector. In this case, interference between the speed detection response and the filter is likely to occur in the low-speed range where the filter's cutoff frequency is low. Also, if the filter's attenuation rate or bandwidth is increased to improve the noise reduction effect, the phase lag caused by the filter increases, making it more likely that the speed detection response will interfere with the filter's phase lag. Furthermore, if the speed detection response is increased, the cutoff frequencies of the speed detection response and the filter will become closer, making it more likely that the filter's phase lag will interfere with it.

[0008] As described above, in the known technology, the challenge is to maintain the operation and noise reduction effect of the variable notch filter in the low speed range while simultaneously achieving high speed detection response. Therefore, an object of the present invention is to provide a technology for removing noise from a speed detector using a variable notch filter, which narrows the cutoff frequency bandwidth of the filter in the low speed range to prevent interference between the phase lag of the filter and the phase lag of the speed detection response, and widens the bandwidth in the high speed range to obtain a high noise reduction effect for frequency components around the cutoff frequency. [Means for solving the problem]

[0009] In order to solve the above problems, one representative control device for a rotating electric machine according to the present invention includes a speed detection unit that detects the rotational speed of the rotating electric machine and outputs it as a rotational speed detection signal, a filter that receives the rotational speed detection signal as input and removes noise in a specific frequency band that depends on the rotational speed and that is superimposed on the rotational speed detection signal, a bandwidth setting unit that receives the rotational speed detection signal as input and sets the bandwidth of the cutoff frequency of the filter, and a voltage command calculation unit that calculates a voltage command from the output of the filter, wherein the bandwidth setting unit sets the bandwidth wider as the rotational speed increases. [Effects of the Invention]

[0010] According to the present invention, when noise is removed using a variable notch filter, interference between the phase lag of the filter and the phase lag of the speed detection response can be prevented by narrowing the cutoff frequency bandwidth of the filter in the low-speed range. Furthermore, the bandwidth is narrowed while maintaining the attenuation rate, reducing the phase lag of the filter, thereby maintaining the noise reduction effect at the cutoff frequency. Furthermore, in the high-speed range, the cutoff frequency bandwidth is widened, achieving a high noise reduction effect for frequency components around the cutoff frequency. Problems, configurations, and effects other than those described above will become apparent from the following description of the preferred embodiments. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing an overall block configuration of a driving device for a rotating electric machine according to a first embodiment; [Figure 2] 10A and 10B are diagrams illustrating an example of noise superimposed on a rotation speed detection value of a speed detection unit. [Figure 3] 10 is a diagram showing an example of phase information when the rotating electric machine rotates at a constant speed; FIG. [Figure 4] FIG. 10 is a Bode diagram showing an example of frequency characteristics when the cutoff frequency of a filter is changed. [Figure 5] FIG. 10 is a Bode diagram showing an example of frequency characteristics when the bandwidth of a filter is changed. [Figure 6] FIG. 4 is a diagram illustrating an example of frequency characteristics of a filter. [Figure 7] FIG. 2 is a block diagram illustrating a configuration of a bandwidth setting unit included in the first embodiment. [Figure 8] FIG. 4 is a diagram illustrating an example of bandwidth setting in a bandwidth setting unit included in the first embodiment. [Figure 9] FIG. 10 is a diagram showing an example of frequency characteristics when a filter with a set bandwidth is combined with a speed detector. [Figure 10] FIG. 10 is a block diagram illustrating a control device according to a second embodiment. [Figure 11] FIG. 10 is a diagram showing an overall block configuration of a driving device for a rotating electric machine according to a third embodiment. [Figure 12] FIG. 11 is a block diagram illustrating a configuration of an attenuation rate setting unit included in the third embodiment. [Figure 13] FIG. 10 is a Bode diagram showing an example of frequency characteristics when the attenuation rate of a filter is changed. [Figure 14] FIG. 10 is a block diagram illustrating a configuration of a filter activation unit included in a fourth embodiment. [Figure 15] 10A and 10B are diagrams illustrating an example of filter output gain setting by a filter output gain setting unit. [Figure 16] FIG. 2 is a diagram illustrating a block configuration of a filter output activation ratio calculation unit. [Figure 17] FIG. 10 is a block diagram illustrating a control device according to a fifth embodiment. [Figure 18] FIG. 10 is a Bode plot showing an example of the result of a cutoff frequency corrected by a prewarping processor. [Figure 19] FIG. 10 is a diagram showing an overall block configuration of a driving device for a rotating electric machine according to a sixth embodiment. [Figure 20] FIG. 13 is a block diagram illustrating a control device according to a seventh embodiment. [Figure 21] FIG. 20 is a block diagram illustrating a configuration of a bandwidth setting unit added in a seventh embodiment. [Figure 22] FIG. 13 is a block diagram illustrating a control device according to an eighth embodiment. [Figure 23] FIG. 13 is a block diagram illustrating a control device according to a ninth embodiment. [Figure 24] FIG. 23 is a diagram showing an overall block configuration of a driving device for a rotating electric machine according to a tenth embodiment. [Figure 25] FIG. 20 is a diagram showing an overall block configuration of a driving device for a rotating electric machine according to an eleventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, with reference to the drawings, embodiments 1 to 11 will be described as modes for carrying out the present invention. Note that the present invention is not limited to these embodiments. In addition, in the description of the drawings, the same parts are denoted by the same reference numerals. [Example]

[0013] FIG. 1 is a block diagram illustrating an overall configuration of a driving device for a rotating electric machine according to a first embodiment. The driving device for a rotating electric machine according to the first embodiment includes a rotating electric machine 1, a power converter 2, and a control device 3. The rotating electric machine 1 is rotated by a voltage applied by the power converter 2. The power converter 2 outputs a predetermined voltage to the rotating electric machine 1 in accordance with a voltage command input from the control device 3.

[0014] The control device 3 has a speed detection unit 10, a filter 11, a bandwidth setting unit 12 and a voltage command calculation unit 13, and uses information on the rotation speed or rotation position of the rotating electrical machine 1 as input, and outputs a voltage command to the power converter 2.

[0015] The speed detection unit 10 detects the rotation speed or rotation position of the rotating electric machine 1, and inputs information on the rotation speed calculated from the rotation speed or rotation position into the control device 3. The speed detection unit 10 may be a device that calculates speed from position information such as a resolver, a PG sensor that obtains speed from magnetic or optical pulse signals, or a device that calculates speed such as an encoder, and is not limited to a specific device.

[0016] However, due to the influence of the structure of the rotating electric machine 1 or the speed detection unit 10, noise of frequency components proportional to the rotation speed of the rotating electric machine 1 is superimposed on the rotation speed of the rotating electric machine 1 detected by the speed detection unit 10.

[0017] The filter 11 provided in the control device 3 is a filter that removes certain frequency components, and removes noise of frequency components proportional to the rotational speed that is superimposed on the speed detection value of the rotating electric machine 1 detected by the speed detection unit 10.

[0018] The transfer function of the filter 11 is expressed, for example, as in the following equation (1).

number

[0019] The filter 11 is not limited to a filter having the characteristics of equation (1), and is not limited to a particular type or form of filter as long as it has a predetermined cutoff frequency, attenuation rate, and bandwidth.

[0020] Furthermore, since the cutoff frequency of the filter 11 is determined by the rotation speed of the rotating electrical machine 1, the filter 11 acquires the rotation speed of the rotating electrical machine 1 detected by the speed detection unit 10 in order to determine this cutoff frequency.

[0021] The bandwidth setting unit 12 receives the rotation speed of the rotating electrical machine 1 detected by the speed detection unit 10 as an input and sets the bandwidth of the filter 11 .

[0022] 2 is a diagram showing an example of noise superimposed on the rotation speed detection value of the speed detection unit 10 due to errors in the structure of the rotating electrical machine 1 or the speed detection unit 10. The solid line represents the rotation speed detection value, and the dotted line represents the actual rotation speed.

[0023] The rotation speed detection value contains superimposed vibrations with frequency components n times the actual rotation speed. Furthermore, when phase information is used to detect the rotation speed, the amplitude of this noise increases in proportion to the rotation speed. In the following description, the rotation speed detection value may be abbreviated as the speed detection value, and the rotation speed may be abbreviated as the speed.

[0024] 3 is a diagram showing an example of phase information when the rotating electrical machine 1 is rotating at a constant speed. The dashed line indicates the phase when there is no error in the structure of the speed detection unit 10, and the solid line indicates the phase when there is an error in the speed detection unit 10.

[0025] The speed detection unit 10 differentiates this phase to obtain the rotation speed. If there is no error in the structure, the speed will be constant, but if there is an error in the structure, noise proportional to the rotation speed will be superimposed on the speed. Furthermore, if the rotation speed is fast, the phase change due to the structural error will also be fast. Therefore, when the rotation speed is obtained by differentiating the phase information, the amplitude of the rotation speed noise will increase, and the higher the speed, the greater the noise amplitude.

[0026] 4 is a Bode plot showing an example of frequency characteristics when the speed detection unit 10 is combined with the filter 11 and the cutoff frequency of the filter 11 is changed. The solid line shows the frequency characteristics of the speed detection unit 10 alone, the dashed line shows the frequency characteristics when combined with the filter 11 having a high cutoff frequency, and the dotted line shows the frequency characteristics when combined with the filter 11 having a low cutoff frequency.

[0027] When the cutoff frequency is low, the phase characteristics of the filter 11 interfere with the phase characteristics of the speed detection unit 10 at the cutoff frequency corresponding to the speed detection response of the speed detection unit 10 (indicated as "cutoff frequency of the speed detection unit" in FIG. 4), and the phase delay of the speed detection response increases. As a result, the response is delayed from the original speed detection response, affecting the next voltage command calculation. For this reason, it is necessary to limit the filter operation in the low speed range where the cutoff frequency of the filter 11 is low.

[0028] 5 is a Bode plot showing an example of the frequency characteristics when the speed detection unit 10 is combined with the filter 11 and the bandwidth of the filter 11 is changed. The solid line shows the frequency characteristics of the speed detection unit 10 alone, the dashed line shows the frequency characteristics when combined with a filter with a large bandwidth, and the dotted line shows the frequency characteristics when combined with a filter with a small bandwidth. Regardless of the bandwidth, the attenuation rate of the cutoff frequency of the filter 11 is the same.

[0029] At the cutoff frequency corresponding to the speed detection response of the speed detection unit 10, the filter with a large bandwidth (dashed line) has the phase characteristic of the filter 11 interfere with the phase characteristic of the speed detection unit 10, resulting in an increased phase lag. In contrast, the filter with a small bandwidth (dotted line) has the phase characteristic of the filter 11 not interfere with the phase characteristic of the speed detection unit 10, so the characteristic of the speed detection unit 10 is the desired characteristic.

[0030] In this way, when the cutoff frequency of the filter 11 is close to the cutoff frequency corresponding to the speed detection response of the speed detection unit 10, it is possible to avoid interference by narrowing the bandwidth. In other words, the bandwidth is determined according to the difference between the cutoff frequency of the filter 11 and the cutoff frequency corresponding to the speed detection response of the speed detection unit 10, thereby suppressing the phase delay caused by the filter 11.

[0031] 6 is a diagram showing an example of the frequency characteristics of the filter 11. The solid line indicates the desired filter characteristics, and the dashed line indicates the characteristics of the filter 11 in which an error occurs due to the sampling period. A variable notch filter that removes specific frequency components has a problem in that when the cutoff frequency approaches the sampling frequency of the control device 3, the cutoff frequency deviates from the desired cutoff frequency.

[0032] In general, the sampling frequency of the control device 3 is higher than the cutoff frequency of the filter 11. Therefore, in the high speed range, the deviation of the cutoff frequency becomes large, and the noise superimposed on the rotation speed detection value of the speed detection unit 10 also becomes large. For these reasons, in the high-speed range, it is necessary to set the bandwidth of the filter 11 to be wide in order to enhance the noise reduction effect.

[0033] In the prior art, in order to operate the filter in the low-speed range, the bandwidth of filter 11 is set narrow, reducing the noise reduction effect in the high-speed range, or the bandwidth is set wide in the high-speed range to ensure the noise reduction effect in the high-speed range. Also, in the low-speed range, it is necessary to stop the operation of filter 11 or slow down the speed detection response of speed detection unit 10 to avoid interference between the speed response of filter 11 and speed detection unit 10. Therefore, it is difficult to simultaneously maintain the noise reduction effect in the high-speed range and increase the operation of filter 11 and the speed detection response of speed detection unit 10 in the low-speed range.

[0034] Therefore, in this embodiment, the bandwidth of the filter 11 is set narrow in the low-speed range, and set wide in the high-speed range to improve the noise reduction effect. To achieve this, the bandwidth setting unit 12 is provided to make the bandwidth of the filter 11 variable, thereby solving the problems of the conventional technology.

[0035] 7 is a control block diagram of the bandwidth setting unit 12 provided in the embodiment 1. The bandwidth setting unit 12 has a cutoff frequency calculation gain 21 and a bandwidth setting table 22. The cutoff frequency calculation gain 21 receives the rotation speed detection value as an input, multiplies the rotation speed detection value by a gain corresponding to the superimposed noise component, and calculates the cutoff frequency.

[0036] The bandwidth setting table 22 receives the known speed detection response and cutoff frequency of the speed detection unit 10 as input and uses table data that outputs a bandwidth to determine the bandwidth of the filter 11. In the first embodiment, the bandwidth setting table is used, but the present invention is not limited to the embodiment that uses a table as long as it has a function of setting the bandwidth from the cutoff frequency and the speed detection response.

[0037] FIG. 8 is a diagram illustrating an example of bandwidth setting in the bandwidth setting unit 12 included in the first embodiment. The bandwidth for the cutoff frequency is set to increase as the rotation speed increases, but the bandwidth is expanded to the extent that no phase delay occurs due to the filter 11 at the cutoff frequency corresponding to the speed detection response of the speed detector 10.

[0038] In the first embodiment, in the low-speed range where the cutoff frequency is small, the bandwidth is set narrow to prevent interference between the filter and the speed detection response. In the high-speed range where the cutoff frequency is large, the bandwidth is widened to increase the attenuation rate even when the noise frequency component deviates from the cutoff frequency, thereby improving the noise reduction effect.

[0039] 9 is a diagram showing an example of frequency characteristics when the filter 11, whose bandwidth is set by the bandwidth setting unit 12 provided in the first embodiment, is combined with the speed detection unit 10. The solid line indicates the speed detection response of the speed detection unit 10, the dashed line indicates the frequency characteristics in the low speed range when the filter 11 is combined with the speed detection unit 10, and the dotted line indicates the frequency characteristics in the high speed range when the filter 11 is combined with the speed detection unit 10.

[0040] By making the bandwidth variable by the bandwidth setting unit 12, interference with the speed detection response of the speed detection unit 10 is prevented in the low speed range, enabling filtering operation, and in the high speed range, the bandwidth is widened within a range that does not interfere with the speed detection response of the speed detection unit 10, thereby improving the noise reduction effect. [Example]

[0041] 10 is a block diagram showing a configuration of a control device 3 according to a second embodiment of the present invention, which is included in a driving device for a rotating electric machine. The configuration differs from that shown in the first embodiment in that a filter enabling unit 14 is added to the control device 3.

[0042] The filter enabling unit 14 has a function of switching between enabling and disabling the output from the filter 11. When the filter output is enabled, the filter output from the filter 11 is output. When the filter output is disabled, the speed detection value of the speed detection unit 10 is directly output. Furthermore, the filter enabling unit 14 enables the filter output when the cutoff frequency of the filter 11 is higher than the cutoff frequency corresponding to the speed detection response of the speed detection unit 10.

[0043] The filter enabling unit 14 switches between enabling and disabling the filter output by switching between input and output, but the configuration for this is not limited. Also, the frequency at which the filter is switched between enabling and disabling is set to the point at which the cutoff frequency of the filter 11 exceeds the speed detection response of the speed detection unit 10, but the switching frequency is not limited as long as the characteristics of the filter 11 are in a range that does not interfere with the speed detection characteristics of the speed detection unit 10. [Example]

[0044] 11 is a diagram showing an overall block configuration of a driving device for a rotating electric machine according to the third embodiment. The difference from the configuration of the first embodiment is that the control device 3 includes a damping factor setting unit 15. The third embodiment is also applicable to the second embodiment.

[0045] The attenuation factor setting unit 15 receives the rotation speed of the rotating electric machine 1 detected by the speed detection unit 10 as an input, and sets the attenuation factor at the cutoff frequency (center frequency) of the filter 11. Here, the configuration of the attenuation factor setting unit 15 is not particularly limited as long as it is configured to set the attenuation factor using the rotation speed, such as table data receiving the rotation speed as an input, or calculation of the attenuation factor using the rotation speed.

[0046] 12 is a block diagram showing the configuration of the attenuation factor setting unit 15 provided in the embodiment 3. The attenuation factor setting unit 15 has a cutoff frequency calculation gain 23 and an attenuation factor setting table 24.

[0047] The cutoff frequency calculation gain 23 receives the rotation speed detection value as an input, and calculates the cutoff frequency by multiplying the rotation speed detection value by a gain according to the superimposed noise component.

[0048] The attenuation rate setting table 24 receives the speed detection response of the speed detection unit 10 and the cutoff frequency from the cutoff frequency calculation gain 23 as inputs, and determines the attenuation rate of the cutoff frequency of the filter 11 using table data that outputs an attenuation rate. In this case, the attenuation rate at the cutoff frequency of the filter 11 may be increased in accordance with an increase in the rotation speed detection value. Here, the attenuation rate setting table 24 is used, but the configuration is not particularly limited as long as it is capable of setting the attenuation rate from the cutoff frequency and the speed detection response of the speed detection unit 10.

[0049] 13 is a Bode plot showing an example of frequency characteristics when the speed detection unit 10 is combined with the filter 11 and the attenuation rate of the filter 11 is changed. The solid line shows the frequency characteristics of the speed detection unit 10 alone, the dotted line shows the frequency characteristics when combined with a filter with a small attenuation rate, and the dashed line shows the frequency characteristics when combined with a filter with a large attenuation rate.

[0050] By lowering the attenuation rate, the effect of the gain characteristics of the filter 11 on the gain characteristics of the speed detection unit 10 is reduced, making it possible to suppress the effect on the detection value of the speed detection unit 10. [Example]

[0051] FIG. 14 is a block diagram illustrating a configuration of the filter enabling unit 14 according to the fourth embodiment. The difference from the previous second embodiment, which includes the filter enabling unit 14, is that the filter enabling unit 14 gradually enables the filter output using two thresholds, a first threshold and a second threshold. Also, the fourth embodiment is applicable to the third embodiment.

[0052] The filter enabling unit 14 according to the fourth embodiment includes a filter gain setting unit 31 and a filter output enabling ratio calculation unit 32, and gradually enables the filter by changing the ratio at which the filter output and the rotation speed detection value are added.

[0053] The filter gain setting unit 31 receives the first threshold, the second threshold, and the rotation speed detection value from an external device. Alternatively, the first threshold and the second threshold may be stored internally. The filter gain setting unit 31 determines the filter output gain from the first threshold, the second threshold, and the rotation speed detection value. Here, the filter output gain is defined between 0 and 1.

[0054] The filter output activation ratio calculation unit 32 receives the filter output gain from the filter gain setting unit 31, the rotation speed detection value, and the filter output from the filter 11 as input, and calculates the output ratio between the filter output and the rotation speed detection value based on the filter output gain. In accordance with this calculation ratio, the filter output and the rotation speed detection value are added together, and the filter 11 is gradually activated.

[0055] FIG. 15 is a diagram showing an example of filter output gain setting by the filter gain setting unit 31. In FIG. The filter output gain is 0 when the rotation speed is less than the first threshold, is 1 when the rotation speed is equal to or greater than the second threshold, and is a value that gradually changes between 0 and 1 between the first and second thresholds. In Fig. 15, the filter output gain is increased linearly between 0 and 1, but the manner of increase is not limited as long as it is a method that continuously increases.

[0056] FIG. 16 is a block diagram showing the configuration of the filter output activation ratio calculation unit 32. As shown in FIG. The filter output activation ratio calculation unit 32 includes a filter output ratio setting unit 33 and a rotation speed detection value ratio setting unit 34, and receives the filter output gain, the filter output, and the rotation speed detection value as inputs.

[0057] The filter output ratio setting unit 33 multiplies the filter output gain by the filter output. The rotation speed detection value ratio setting unit 34 subtracts the filter output gain from 1 to obtain a rotation speed detection value gain, and multiplies the rotation speed detection value by the result.

[0058] The outputs of the filter output ratio setting unit 33 and the rotation speed detection value ratio setting unit 34 are added together to output a rotation speed filter value according to the filter output activation ratio. Since the filter output gain changes gradually, the ratio of signals for which the filter 11 is active and the ratio of signals for which the filter 11 is inactive, among the rotation speed filter values ​​to be output, gradually changes. This gradually switches the ratio between the active and inactive states of the filter 11. In the example shown in FIG. 16, the ratio between the active and inactive states of the filter is gradually switched depending on the gain, but the configuration of the filter output activation ratio calculation unit is not limited as long as the ratio between the active and inactive states of the filter is gradually switched. [Example]

[0059] FIG. 17 is a block diagram illustrating a configuration of the control device 3 according to the fifth embodiment. The difference from the configuration shown in the first embodiment is that a pre-warping processor 16 is added.

[0060] The speed detection unit 10 and the filter 11 are calculated at every calculation cycle and controlled in a discrete system. When control is performed in a discrete system, there is a problem that the cutoff frequency of the filter 11 deviates from the set frequency based on the calculation cycle (calculation frequency) of the control. When the calculation frequency of the speed detection unit 10 and the filter 11 approaches the cutoff frequency of the filter 11, the cutoff frequency of the filter 11 deviates from the original cutoff frequency. Therefore, the deviation of the cutoff frequency of the discrete system filter 11 caused by the calculation cycle (calculation frequency) is corrected by correcting the rotation speed detection value using the prewarping processing unit 16.

[0061] FIG. 18 is a Bode diagram showing an example of the result of the cutoff frequency corrected by the prewarping processor 16. In FIG. If prewarping is not performed on the original filter characteristics, the cutoff frequency of filter 11 will deviate from the desired cutoff frequency, and it will be necessary to widen the bandwidth to compensate for the decrease in noise attenuation due to the deviation in the cutoff frequency. Therefore, the effect of narrowing the bandwidth of filter 11 to expand the filter operating range in the low-speed range is limited.

[0062] On the other hand, when prewarping is performed, the cutoff frequency coincides with the original filter characteristics. Therefore, adding the prewarping processor 16 prevents deviation of the cutoff frequency, allowing the bandwidth to be narrowed. This enhances the effect of expanding the filter operating range. This prewarping processor 16 can also be applied to the second to fourth embodiments. [Example]

[0063] FIG. 19 is a diagram illustrating an overall block configuration of a driving device for a rotating electric machine according to a sixth embodiment. The difference from the configuration shown in the first embodiment is that the power converter 2 is an inverter 4 driven by a PWM control unit 17, and the control device 3 synchronizes with the carrier frequency of the PWM control unit 17 and performs calculations at a variable calculation period.

[0064] The inverter 4 applies an AC voltage to the rotating electric machine 1 by switching internal elements based on pulses calculated by the PWM control unit 17, and controls the speed and current of the rotating electric machine 1 by changing the voltage and frequency of this AC voltage.

[0065] PWM control unit 17 compares the voltage command calculated by voltage command calculation unit 13 with the PWM carrier, which is a triangular wave that fluctuates at the carrier frequency, and outputs a gate pulse. This gate pulse switches the elements of inverter 4 to obtain the desired output voltage.

[0066] In the sixth embodiment, the calculation of the control device 3 is performed in synchronization with the carrier frequency. When synchronous PWM control is performed in which the carrier frequency is changed in synchronization with the frequency of the inverter output voltage, the calculation time of the control device is proportional to the frequency of the inverter. Since the frequency of the inverter 4 and the rotation speed of the rotating electric machine 1 are proportional, the relationship between the calculation time of the control device 3 and the cutoff frequency of the filter 11 always matches. Furthermore, the sixth embodiment can also be applied to the second to fifth embodiments.

[0067] As a result, the influence of the shift in cutoff frequency due to the calculation time of the filter 11 is the same across the entire speed range, making it easier to determine the bandwidth when setting it. [Example]

[0068] FIG. 20 is a block diagram illustrating a configuration of the control device 3 according to the seventh embodiment. The difference from the configuration shown in the first embodiment is that there are multiple configurations of the filter 11 and the bandwidth setting unit 12. For example, as shown in Fig. 20, a combination of a filter 11a and a bandwidth setting unit 12a is added after the combination of the filter 11 and the bandwidth setting unit 12.

[0069] The difference between filter 11 and filter 11a is that the cutoff frequency of the filter is different, and the cutoff frequency of filter 11a is proportional to the rotation speed of the rotating electric machine 1 and is a frequency different from the cutoff frequency of filter 11. For example, it corresponds to the frequency of second, fourth, etc. harmonics. Furthermore, the bandwidth setting unit 12a sets the bandwidth in accordance with the cutoff frequency of the filter 11a.

[0070] FIG. 21 is a block diagram showing the configuration of a bandwidth setting unit 12a added in the seventh embodiment. The bandwidth setting unit 12a is made up of a cutoff frequency calculation gain 21a and a bandwidth setting table 22. The cutoff frequency calculation gain 21a is a different value from the cutoff frequency calculation gain 21, and determines a cutoff frequency different from that of the filter 11.

[0071] By connecting the filter 11 and the filter 11a in series, it becomes possible to remove noise from two frequency components proportional to the rotation speed of the rotating electrical machine 1. Furthermore, since the bandwidth setting unit 12 and the bandwidth setting unit 12a respectively set the bandwidths of the filter 11 and the filter 11a, interference between each filter and the speed detection response of the speed detection unit 10 is prevented, and it becomes possible to remove multiple noise components superimposed on the rotation speed. 20 shows the seventh embodiment in which there are two combinations of filters and bandwidth setting units, but the number of combinations may be two or more. Furthermore, the seventh embodiment is also applicable to the third, fifth, and sixth embodiments. [Example]

[0072] FIG. 22 is a block diagram illustrating a configuration of the control device 3 according to the eighth embodiment. The difference from the configuration shown in the seventh embodiment is that a filter enabling unit is provided after each filter. The filter enabling unit 14 and the filter enabling unit 14a have the function of enabling the output of the filter when the cutoff frequency of the filter 11 and the filter 11a is equal to or higher than a predetermined threshold, respectively, and when the cutoff frequency is equal to or lower than the predetermined threshold, the output of the filter is disabled and the input to the filter is output as is.

[0073] The filter enabling unit 14 and the filter enabling unit 14a differ in the cutoff frequencies used to determine whether a filter is enabled or disabled. Since the cutoff frequencies of the filters 11 and 11a are different, the filter enabling unit 14 enables the output of the filter 11 when the cutoff frequency of the filter 11 exceeds a first threshold, and the filter enabling unit 14a enables the output of the filter 11a when the cutoff frequency of the filter 11a exceeds a second threshold. In this case, a method of sequentially enabling the filters starting from the filter with the highest cutoff frequency may be employed. [Example]

[0074] FIG. 23 is a block diagram illustrating a configuration of a control device 3 according to a ninth embodiment. The difference from the configuration shown in the seventh embodiment is that the inputs to the bandwidth setting unit 12 and the bandwidth setting unit 12a are rotation speed detection values, and the rotation speed detection values ​​are used to determine the cutoff frequencies of the filters 11 and 11a.

[0075] If the rotation speed detection value detected by the speed detection unit 10 changes instantaneously, the operation of the filter 11 may become unstable. In this case, if the output of the filter 11 is used as is for the filter 11a, the unstable operation of the filter 11 will also make the operation of the filter 11a unstable, and the operation of the control device 3 will become unstable.

[0076] In contrast to this, according to the ninth embodiment, the rotation speed detection value detected by the speed detection unit 10 is used as the input to the filter 11 and the filter 11a, so that the control of the control device 3 can be prevented from becoming unstable. [Example]

[0077] FIG. 24 is a diagram illustrating an overall block configuration of a driving device for a rotating electric machine according to a tenth embodiment. The difference from the configuration shown in the first embodiment is that the control device 3 includes a speed command calculation unit 41 and a speed control unit 42, and the voltage command calculation unit 13 shown in the first embodiment that calculates a voltage command from the filter output is replaced by a voltage command calculation unit 13a that calculates a voltage command from the torque command output by the speed control unit 42.

[0078] The speed command calculation unit 41 calculates a speed command from the value of the filter output (rotation speed) output from the filter 11, and outputs the speed command to the speed control unit . The speed control unit 42 outputs a torque command for controlling the speed based on the speed command and the filter output.

[0079] The voltage command calculation unit 13 a calculates a voltage command from the torque command output by the speed control unit 42 , and outputs the voltage command to the power converter 2 . In the tenth embodiment, the speed control response of the speed control unit 42 is determined by the speed detection response of the speed detection unit 10, and the bandwidth setting in the bandwidth setting unit 12 is set based on the speed detection response of the speed detection unit 10, similar to the first embodiment. Moreover, the tenth embodiment is also applicable to the second to ninth embodiments. [Example]

[0080] FIG. 25 is a block diagram illustrating an overall configuration of a driving device for a rotating electric machine according to an eleventh embodiment. The difference from the configuration shown in the tenth embodiment is that a current command calculation unit 43 and a current control unit 44 are provided instead of the voltage command calculation unit 13a.

[0081] The current command calculation unit 43 calculates a current command based on the torque command output from the speed control unit 42. The current control unit 44 obtains a voltage command for controlling the current based on the current command output from the current command calculation unit 43 and the detected current value obtained from the rotating electric machine 1. In the eleventh embodiment, in addition to the control response aspects shown in the tenth embodiment, the current control response of the current control unit 44 is determined based on the speed control response of the speed control unit 42.

[0082] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the present invention. [Explanation of symbols]

[0083] 1... Rotating electric machine, 2... Power converter, 3... Control device, 10... Speed ​​detection unit, 11, 11a... Filter, 12, 12a... Bandwidth setting unit, 13, 13a... Voltage command calculation unit, 14, 14a... Filter activation unit, 15... Attenuation rate setting unit, 16... Pre-warping processing unit, 17... PWM control unit, 21, 21a, 23... Cutoff frequency calculation gain, 22... Bandwidth setting table, 24... Attenuation rate setting table, 31... Filter gain setting unit, 32... Filter output activation rate calculation unit, 33... Filter output rate setting unit, 34... Rotational speed detection value rate setting unit, 41... Speed ​​command calculation unit, 42... Speed ​​control unit, 43... Current command calculation unit, 44... Current control unit

Claims

1. A control device for a rotating electric machine that outputs a voltage command to a power converter that supplies power to the rotating electric machine and controls the power converter, a speed detection unit that detects the rotation speed of the rotating electric machine and outputs the detected rotation speed as a rotation speed detection signal; a filter that receives the rotation speed detection signal as an input and removes noise in a specific frequency band that depends on the rotation speed and that is superimposed on the rotation speed detection signal; a bandwidth setting unit that receives the rotation speed detection signal as an input and sets a bandwidth of a cutoff frequency of the filter; a voltage command calculation unit that calculates the voltage command from the output of the filter; Equipped with The bandwidth setting unit sets the bandwidth to be wider as the rotation speed increases. A control device for a rotating electric machine characterized by:

2. The control device for a rotating electric machine according to claim 1, The bandwidth setting unit sets the bandwidth in accordance with a difference between a cutoff frequency of the filter and a cutoff frequency corresponding to a speed detection response of the speed detection unit, thereby suppressing a phase delay caused by the filter. A control device for a rotating electric machine characterized by:

3. The control device for a rotating electric machine according to claim 1 or 2, The speed detector further includes a filter enabling unit that enables an output from the filter when a cutoff frequency of the filter is higher than a cutoff frequency corresponding to a speed detection response of the speed detector. A control device for a rotating electric machine characterized by:

4. The control device for a rotating electric machine according to any one of claims 1 to 3, an attenuation rate setting unit that increases the attenuation rate at the cutoff frequency of the filter in response to an increase in the rotation speed; A control device for a rotating electric machine characterized by:

5. The control device for a rotating electric machine according to any one of claims 1 to 4, a filter enabling unit that enables an output from the filter in a manner that continuously increases with respect to the rotation speed when the rotation speed of the rotation speed detection signal is between a first threshold value for the rotation speed and a second threshold value that is greater than the first threshold value; A control device for a rotating electric machine characterized by:

6. The control device for a rotating electric machine according to any one of claims 1 to 5, a correction processing unit that corrects a deviation in the cutoff frequency of the filter that occurs based on the calculation cycle of the control device A control device for a rotating electric machine characterized by:

7. 7. The control device for a rotating electric machine according to claim 1, 2, 4 to 6, The filter is configured by connecting a plurality of filters having different cutoff frequencies in series, and the bandwidth setting unit is provided for each of the plurality of filters. A control device for a rotating electric machine characterized by:

8. The control device for a rotating electric machine according to claim 7, A filter enabling unit is provided for each of the plurality of filters to enable the output of each of the plurality of filters, and the filter enabling unit is activated sequentially from the filter with the highest cutoff frequency to the filter with the highest cutoff frequency. A control device for a rotating electric machine characterized by:

9. The control device for a rotating electric machine according to claim 7, The rotation speed detection signal is input to each of the plurality of filters and the bandwidth setting unit. A control device for a rotating electric machine characterized by:

10. The control device for a rotating electric machine according to any one of claims 1 to 9, a speed control unit that controls the rotation speed of the rotating electric machine; a speed command calculation unit that calculates a speed command for the speed control unit; Further provided with the speed command calculation unit receives the output of the filter as an input; the speed control unit receives the speed command and the output of the filter as inputs; The voltage command calculation unit calculates the voltage command from the output of the speed control unit. A control device for a rotating electric machine characterized by:

11. The control device for a rotating electric machine according to claim 10, Further provided with a current command calculation unit and a current control unit instead of the voltage command calculation unit, the current command calculation unit calculates a current command using the output of the speed control unit as an input; The current control unit calculates the voltage command based on the current command and a detected current value from the rotating electric machine. A control device for a rotating electric machine characterized by:

12. A method for controlling a rotating electric machine, which outputs a voltage command to a power converter that supplies power to the rotating electric machine and controls the power converter, comprising: Detecting a rotational speed signal of the rotating electric machine; a filter that receives the detected rotation speed signal as an input removes noise in a specific frequency band that is superimposed on the rotation speed signal and that depends on the rotation speed of the rotation speed signal; when setting a bandwidth of a cutoff frequency of the filter from the detected rotation speed signal, the bandwidth is set to be wider as the rotation speed increases; The voltage command is calculated from the output of the filter. A method for controlling a rotating electric machine comprising:

13. A method for controlling a rotating electric machine according to claim 12, comprising: The bandwidth is set in accordance with the difference between the cutoff frequency of the filter and the cutoff frequency corresponding to the speed detection response when detecting the rotation speed signal, thereby suppressing the phase delay caused by the filter. A method for controlling a rotating electric machine comprising:

14. A method for controlling a rotating electric machine according to claim 12 or 13, comprising: The output from the filter is enabled when the cutoff frequency of the filter is higher than the cutoff frequency corresponding to the speed detection response when detecting the rotation speed signal. A method for controlling a rotating electric machine comprising:

15. A method for controlling a rotating electric machine according to any one of claims 12 to 14, comprising: Increasing the attenuation rate at the cutoff frequency of the filter in response to an increase in the rotational speed A method for controlling a rotating electric machine comprising:

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