JP6222834B2 - Motor control device - Google Patents

Description

  The present invention relates to a motor control device that detects a rotational speed of a motor and controls the motor.

  In a motor control device that controls a motor by an inverter, the rotation angle of the motor is detected by an angle detector such as a resolver to control the motor torque. The detected rotation angle of the motor is used when the motor control device converts the detection result of the alternating current of the motor into the dq axis current, or when converting the dq axis voltage command into the alternating voltage command. Used for number arithmetic.

  The rotation angle detected by the resolver includes an error due to the structure of the resolver, and the magnitude of the error is determined to be a unique value with respect to the actual angle (0 to 360 degrees) of the resolver. When the resolver angle changes from 0 to 360 degrees, the error changes accordingly. That is, when the resolver rotates, the rotation angle error has a component proportional to the resolver rotation frequency.

  The motor rotation speed calculated by the rotation angle having such an error includes an error having a resolver rotation frequency component, and this error affects processing using the motor rotation speed. Become. For example, when controlling the motor rotation speed so as to coincide with the rotation speed command, even if the rotation speed command is constant, an error is included in the calculation result of the motor rotation speed, resulting in fluctuations in the motor rotation speed. Become.

  Patent Document 1 discloses a speed at which the amount of speed deviation is reduced by applying a notch filter to the deviation between the rotation speed command and the detected value of the motor rotation speed and making the cut-off frequency of the notch filter variable according to the rotation speed command. A control device is disclosed.

Japanese Patent Laid-Open No. 06-141578

  However, in the speed control device disclosed in Patent Document 1, since the cutoff frequency is determined according to the rotational speed command, the influence of the error of the angle detector is reduced when the rotational speed command is not equal to the motor rotational speed. Can not.

The motor control device of the present invention includes a rotation speed calculation unit that calculates a motor electrical angle rotation speed based on a detection angle of an angle detector that detects a rotation angle of the motor, and a frequency to be cut off based on the motor electrical angle rotation speed. A filter unit that has a notch filter function that makes the motor variable and outputs the motor electrical angular rotation speed after the filter, and a current control unit that controls the motor current based on the motor electrical angular rotation speed and the torque command after the filter, The filter unit further has a low-pass filter function for attenuating a frequency equal to or higher than a predetermined cut-off frequency, and uses the notch filter function and the low-pass filter function to perform filter processing on the motor electrical angular rotation speed, thereby The filter unit disables the notch filter function when the number of rotations is equal to or greater than a threshold value .

  According to the present invention, the influence of an error of an angle detector such as a resolver can be reduced, and a more accurate motor rotation speed can be obtained.

1 is a block diagram including a motor control device according to a first embodiment. The figure which shows the angle error of a resolver. The block diagram of a filter part. (A)-(j) The graph which shows from an angle detection to the rotation speed after a filter. The block diagram of the filter part concerning 2nd Embodiment. The figure which shows the gain characteristic of the filter which combined the primary delay filter and the notch filter function.

(First embodiment)
The configuration of the first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram including a motor control device 20. In addition to the motor control device 20, a DC power supply 10, a contactor 11, a DC voltage sensor 12, an inverter 13, a motor current sensor 14, a motor 15, and a resolver 16 are provided.

  The DC power supply 10 supplies power to the inverter 13 when the contactor 11 is closed. A DC voltage corresponding to the voltage of the DC power supply 10 is detected by the DC voltage sensor 12 and sent to the motor control device 20.

  The inverter 13 incorporates six switching elements (for example, IGBTs), and converts the power from the DC power supply 10 from DC to three-phase AC. Based on the PWM signal sent from the motor control device 20, the switching element is controlled to apply a three-phase AC voltage to the motor 15.

  The motor 15 is composed of a stator having a three-phase winding and a rotor incorporating a magnet, and generates torque by the relationship between the magnetic flux that changes when a current flows through the winding and the magnetic force of the magnet.

  A disturbance torque Tdist corresponding to a load is applied to the motor rotation shaft of the motor 15. The motor current sensor 14 detects the current of three phases flowing through the motor 15, and the detection current signal Imot is sent to the motor control device 20.

  The resolver 16 is an angle detector, and is rotated in synchronization with the motor 15 by being attached to the rotation shaft of the motor 15, and its own angle also changes according to a change in the angle of the rotation shaft of the motor 15. The resolver 16 sends an angle signal θ including the electrical angle information of the resolver 16 to the motor control device 20.

  The motor control device 20 determines the output torque output from the motor 15 based on the external command 40 from the external device 50. Then, an AC voltage necessary for flowing a current corresponding to the output torque to the motor 15 is calculated, and a PWM signal for applying the AC voltage to the motor 15 is generated.

  The angle signal θ including the electrical angle information of the resolver 16 is input to the electrical angle conversion unit 21 of the motor control device 20, and the electrical angle conversion unit 21 converts the angle signal θ into a resolver electrical angle θsns.

  The motor electrical angle calculator 22 calculates the electrical angle θel of the motor 15 from the resolver electrical angle θsns. Assuming that the axial multiple angle of the resolver 16 is X and the number of pole pairs of the motor 15 is PP, the electrical angle θel of the motor 15 is the remainder of dividing the resolver electrical angle θsns by (X ÷ PP) × 360 [deg] (PP ÷ X ).

  For example, when the shaft angle multiplier X = 4 of the resolver 16 and the pole pair number PP = 8 of the motor 15, the electrical angle θel of the motor 15 is calculated by multiplying the remainder of dividing the resolver electrical angle θsns by 180 by 2. .

  The shaft double angle X of the resolver 16 and the pole pair number P.P. of the motor 15 are determined from the control resolution and the maximum value of the rotational speed required for controlling the motor 15, the specification of the output torque, and the like.

The motor electrical angle rotational speed calculation unit 23 calculates the electrical angular rotational speed ωel from the change of the electrical angle θel of the motor 15 over a predetermined time T with the current time as t based on the following Equation 1.
Electrical angle rotational speed ωel (t) = [θel (t) −θel (t−T)] / T Equation 1

  The filter unit 24 performs a filtering process on the electrical angular rotational speed ωel, and outputs the electrical angular rotational speed ωel_flt after the filtering process. The filter unit 24 has a notch filter function that passes only signals having a specific cutoff frequency, but passes signals having other frequencies, and the cutoff frequency is determined based on the electrical angular rotation speed ωel. The gain characteristic of the notch filter function is preferably such that the slope thereof is steep near the cutoff frequency, but the form is not limited as long as it has a characteristic that attenuates to a certain gain at the cutoff frequency.

  The pole pair number calculation unit 25 calculates the mechanical angle rotation number ωmc_flt of the motor 15 by multiplying the electrical angle rotation number ωel_flt after the filter processing by the filter unit 24 by the inverse of the pole pair number PP of the motor 15, and the rotation number control unit 27 and The torque is output to the torque limiter 29.

  Outside the motor control device 20, there is an external device 50 that periodically sends commands to the motor control device 20. The communication unit 26 receives an external command 40 from the external device 50, and each command is stored in the motor control device 20. To each block. The external device 50 is an electronic control unit such as a vehicle control device, for example.

  The communication unit 26 transmits the value calculated and measured in the motor control device 20 to the external device 50. For example, the mechanical angular rotation speed ωmc_flt is periodically sent to the external device 50, and the external device 50 calculates an external command 40 to be sent to the motor control device 20 using the value.

  The rotational speed control unit 27 calculates a torque value necessary to bring the deviation between the external rotational speed command ωtrgt and the mechanical angular rotational speed ωmc_flt close to 0, and outputs it as an internal torque command Tωtrgt. The rotational speed control unit 27 is preliminarily defined with performance such as control response, stability, and robustness against disturbance. In order to achieve this performance, the internal torque command Tωtrgt is set using PI control or disturbance torque estimation calculation. Calculate. Disturbance torque estimation is performed by differentiating the mechanical angular speed ωmc_flt to obtain the acceleration generated on the rotating shaft, estimating the disturbance torque acting on the rotating shaft from there, and canceling the disturbance torque. This operation increases the robustness against disturbance.

  The pre-limit torque selecting unit 28 outputs an external torque command Ttrgt when the external mode command MDtrgt indicates torque control, and outputs an internal torque command Tωtrgt when the external mode command MDtrgt indicates rotation speed control.

  The torque limiter 29 limits the input torque value based on the internal torque limit value and the external torque limit value Tlimt determined based on the mechanical angular speed ωmc_flt, and outputs the result as a torque command Trq *. The internal torque limit value is determined from the relationship between the motor rotation speed, which is a characteristic of the motor 15, and the maximum torque value that can be output. In determining the torque command Trq *, a torque limit for protecting the motor 15 and the inverter 13 may be considered.

  The current control unit 30 generates a dq axis current command corresponding to the torque command Trq *. Then, the dq axis voltage command necessary to bring the deviation of the dq axis detected current value obtained by converting the dq axis current command and the detected current signal Imot into three-phase / two-phase conversion based on the electrical angle θel of the motor 15 close to 0 is calculated. . The dq axis voltage command is converted into a two-phase / three-phase based on the electrical angle θel of the motor 15 to calculate a three-phase voltage command V *. In addition, the current control unit 30 calculates a feedforward control amount for determining the three-phase voltage command V * based on the value of the electrical angular rotation speed ωel_flt after the filtering process.

  The current control unit 30 is preliminarily defined with performance such as control response and stability, and feedback control and feedforward control are used to achieve this performance. The feedforward control cancels the voltage generated at the terminal of the motor 15 due to the rotation of the motor 15, and interferes with the induced voltage of the motor 15 and the d axis and the q axis of the motor 15 based on the mechanical angular rotation speed ωmc_flt. In this control, the voltage is calculated and the transient response of current control is improved by canceling the voltages.

  The PWM generator 31 generates a PWM signal based on the three-phase voltage command V *, and outputs the PWM signal to the inverter 13.

The operation of the first embodiment will be described below.
Due to the structure of the resolver 16, the angle signal θ from the resolver 16 and the resolver electrical angle θsns converted from the angle signal θ include an angle error, and an actual error (0 to 360 [deg]) with no error and an angle error. This relationship is always constant with respect to the angle change, and at the time of the resolver rotation, the angle error has a frequency component proportional to the electrical angle rotation frequency of the resolver 16.

  FIG. 2 shows the relationship between the resolver electrical angle θsns (with error) and the actual angle (without error) when the angle error has a frequency component twice that of the electrical angle rotation frequency of the resolver 16. The graph indicated by the solid line k1 in the figure is the resolver electrical angle θsns with error, and the graph indicated by the one-dot chain line k2 in the figure is the actual angle without error. The relationship between the actual angle and the angle error between the resolver electrical angle θsns is always constant with respect to the actual angle (0 to 360 deg). Thus, when the resolver 16 is rotated, the angular error has a frequency component proportional to the electrical angular rotation frequency of the resolver 16.

  How many times the angular error has a frequency component with respect to the electrical angular rotation frequency of the resolver 16 during the rotation of the resolver depends on the characteristics of the structure of the resolver 16 and the angular error is proportional to the electrical angular rotational frequency of the resolver 16. In some cases, it has a plurality of frequency components. The graph indicated by the solid line k1 in FIG. 2 shows the resolver electrical angle θsns when the frequency component is doubled. The graph indicated by the dotted line k3 in FIG. 2 shows the resolver electrical angle θsns when the frequency component is 1 time. For example, the resolver electrical angle θsns in the case of having multiple frequency components of 1 × and 2 × is a graph obtained by synthesizing the graph indicated by the dotted line k3 and the graph indicated by the solid line k1 in the figure.

  The error of the resolver electrical angle θsns is inherited by the electrical angle θel of the motor 15, and the error is also included in the electrical angle rotational speed ωel calculated from the electrical angle θel of the motor 15. Like the error, it has a frequency component proportional to the electrical angular rotation frequency of the resolver 16.

The resolver 16 and the motor 15 rotate synchronously. When the number of pole pairs of the motor 15 is PP and the resolver shaft multiple angle is X, the electrical angular rotational frequency of the resolver 16 is based on Equation 2 using the electrical angular rotational speed ωel. Calculated.
Resolver 16 electrical angle rotation frequency = ωel × X ÷ PP Equation 2

  Therefore, by determining the cut-off frequency of the notch filter function of the filter unit 24 according to the calculation result, the filter unit 24 introduces an error having a frequency component proportional to the electrical angular rotational frequency of the resolver 16 from the electrical angular rotational frequency ωel. The reduced electrical angle rotational speed ωel_flt after filtering can be calculated.

  Since the electrical angular rotational speed ωel is periodically calculated and the cutoff frequency of the notch filter function changes each time, the error in the electrical angular rotational speed ωel is reduced regardless of the motor rotational speed.

  As shown in the graph shown by the solid line in FIG. 2, when the angular error has a frequency component that is twice the electrical angular rotation frequency of the resolver 16, the frequency obtained by doubling the electrical angular rotational frequency of the resolver 16 obtained by Equation 2 is The cut-off frequency for the notch filter function may be used.

  FIG. 3 is a block diagram showing the configuration of the filter unit 24. A cut-off frequency variable notch filter 241 to which the electrical angular rotation speed ωel is input is provided. Furthermore, a circuit 242 for obtaining the electrical angle rotation frequency of the resolver 16 by Equation 2 and a circuit 243 for obtaining the cutoff frequency by doubling the obtained electrical angle rotation frequency of the resolver 16 are provided. The cut-off frequency variable notch filter 241 calculates and outputs the electrical angle rotational speed ωel_flt after filter processing in which an error having a frequency component proportional to the electrical angular rotational frequency of the resolver 16 is reduced from the electrical angular rotational speed ωel.

  Depending on the characteristics of the resolver 16, there may be a plurality of cutoff frequencies. As described above, when the angle error of the resolver 16 includes a plurality of frequency components that are n times the electrical angular rotation frequency, the filter unit 24 sets the frequency obtained by multiplying the electrical angular rotation frequency by n as the cutoff frequency of the notch filter function. . For example, when the angular error has frequency components that are 1 and 4 times the electrical angular rotation frequency of the resolver 16, a circuit that obtains a frequency obtained by multiplying the electrical angular rotational frequency of the resolver 16 by 1 as shown by the dotted line in FIG. 244 and a circuit 245 for obtaining a frequency obtained by quadrupling the electrical angular rotation frequency of the resolver 16 are added as a cutoff frequency of the notch filter function.

  When the relationship between the frequency of the angle error and the electrical angular rotation frequency of the resolver 16 is known, the cutoff frequency of the notch filter function is added from the relationship. If it is not known, it is possible to rotate the resolver 16 and read the relationship from the waveform of the angle and the number of rotations.

  4A to 4J are graphs showing the calculation results from the motor rotation speed to the mechanical angle rotation speed ωmc_flt and the gain characteristics of the notch filter function.

  4A to 4J, the number of pole pairs (PP) of the motor 15 is 8, the rotational speed of the motor 15 is 1500 [rpm], and the electrical angular rotational speed is 12000 [rpm] (= 1500 (rpm) × 8. (PP)). The axial multiple angle (X) of the resolver 16 is 4, and the frequency of the error of the resolver electrical angle θsns is twice the electrical angular rotation frequency of the resolver 16 as shown by the solid line in FIG.

  As shown in FIG. 4A, when the rotational speed of the motor 15 is 1500 [rpm], the electrical angular rotation frequency of the resolver 16 rotating in synchronization is as shown in FIG. 100 [Hz] (= 1500 (rpm) ÷ 60 (seconds) × 4 (X)).

  Therefore, as shown in FIG. 4C, the resolver electrical angle θsns changes at 100 [Hz] from 0 to 360 [deg], and the error included in the resolver electrical angle θsns as shown in FIG. Is the electrical angle rotation frequency x 2 of the resolver 16.

  As shown in FIG. 4E, the electric angle θel of the motor 15 is obtained by the motor electric angle calculator 22 based on the resolver electric angle θsns. Then, as shown in FIG. 4 (f), the electrical angular rotational speed ωel is obtained by the motor electrical angular rotational speed calculator 23 based on the electrical angle θel of the motor 15.

  Here, as shown in FIG. 4G, it is assumed that the error of the electrical angular rotation speed ωel is +/− 100 [rpm]. This is a value determined from the error magnitude of the resolver electrical angle θsns and the period for calculating the electrical angle rotation speed ωel, and any number will not affect the subsequent explanation, but for ease of explanation. +/- 100 [rpm].

  As shown in FIG. 4 (h), the cutoff frequency of the notch filter function is obtained from the electrical angular rotation speed ωel, and the gain characteristic is a characteristic having a cutoff frequency with a median value of 200 [Hz]. Cutoff frequency = 200 ± 2 [Hz] = 12000 ± 100 (rpm) ÷ 60 (seconds) ÷ 8 (P.P) x 4 (X) x 2 (times)

  By filtering the electrical angle rotational speed ωel with this characteristic by the filter unit 24, as shown in FIG. 4 (i), an electrical angular rotational speed ωel_flt after filtering with reduced errors can be obtained. As shown in FIG. 4J, the electrical angular rotational speed ωel_flt after the filtering process is calculated by the pole pair number calculating unit 25 as the mechanical angular rotational speed ωmc_flt.

  Here, in the gain characteristic of the notch filter function, the attenuation amount at 200 [Hz] is set to −20 [db] (= 10 [%]), but this value reduces the error of the electrical angular rotational speed ωel. It depends on what needs to be done.

The effects of the first embodiment will be described below.
Use of the filtered electrical angle rotational speed ωel_flt or mechanical angular rotational speed ωmc_flt with reduced error provides the following effects.

(1) Effects of the rotation speed control unit 27 The rotation speed control unit 27 calculates the internal torque command Tωtrgt by performing PI control and disturbance torque estimation calculation based on the mechanical angle rotation speed ωmc_flt. The internal torque command Tωtrgt is calculated more accurately than when the error is not reduced. As a result, the speed control performance can be improved.

  Specifically, it is possible to reduce the steady rotational speed fluctuation defined as the rotational speed control performance and to improve the step response performance when the rotational speed command changes stepwise. This is because the notch filter function attenuates only the error frequency band from the electrical angular rotation speed ωel, and passes the frequency band necessary for other step responses.

  Also in the disturbance torque estimation calculation, the error of the mechanical angular speed ωmc_flt that is the subject of differentiation is reduced, so the amount of error amplified by the differentiation process is also reduced, and the disturbance torque compared to the case without this embodiment The accuracy and responsiveness of the estimation calculation can be improved.

  Since the cutoff frequency of the notch filter function is determined not based on the rotational speed command but based on the electrical angular rotational speed ωel, the error can be reduced even when the rotational speed command and the mechanical angular rotational speed ωmc_flt do not match. The state where the rotational speed command and the mechanical angular speed ωmc_flt do not match is that the rotational speed command changes, the motor rotational speed changes toward the command value, the motor rotation is caused by the application of disturbance torque or Tlimt It is assumed that the torque necessary to make the number coincide with the rotational speed command cannot be output.

(2) Effects of the communication unit 26 The communication unit 26 transmits the mechanical angle rotational speed ωmc_flt to the external device 50, and the external device 50 sends the external torque command Ttrgt to the motor control device 20 based on the value of the mechanical angular rotational frequency ωmc_flt. And the external rotational speed command ωtrgt are calculated, but since the error of the mechanical angular rotational speed ωmc_flt is reduced, more accurate external torque command Ttrgt and external rotational speed command ωtrgt can be calculated.

(3) Effect of Torque Limiting Unit 29 Since the error of the mechanical angle rotational speed ωmc_flt is reduced, the torque limiting unit 29 has a torque upper and lower limit value that can be output by the motor 15 based on the value of the mechanical angular rotational speed ωmc_flt. It can be calculated accurately.

(4) Effect of the current control unit 30 The current control unit 30 has a three-phase voltage based on the value of the electrical angle rotational speed ωel_flt after the filtering because the error of the electrical angular rotational speed ωel_flt after the filtering is reduced. The feedforward control amount for determining the command V * can be calculated more accurately.

  The above (2) to (4) are effective in both the torque control mode and the rotation speed control mode.

(Second Embodiment)
The configuration of the second embodiment of the present invention will be described with reference to the drawings.
Since the configuration of the second embodiment is the same as that of the block diagram of the first embodiment shown in FIG. 1, the description of the configuration is omitted. In the second embodiment, the filter unit 24 is different from the first embodiment.

  FIG. 5 shows a block diagram of the filter unit 24 of the second embodiment. The filter unit 24 has a low-pass filter function in addition to the notch filter function. The form of the low-pass filter is not particularly limited, such as a moving average filter, but here, a first-order lag filter 246 that is generally widely used is used.

  The electrical angle rotational speed ωel is first subjected to the first-order lag filtering process by the first-order lag filter 246 in the filter unit 24, and then the circuit 242 for obtaining the electrical angle rotational frequency of the resolver 16 by the above-described equation 2 and the obtained resolver. The circuit 243 for obtaining the cut-off frequency by doubling the electrical angle rotation frequency of 16 performs notch filter processing. The order of the filter processing by the first-order lag filter 246 and the notch filter processing does not affect the effects of the embodiments described later, but here the order is described above.

  The cut-off frequency of the first-order lag filter 246 is determined from the time constant required for the calculation of the electrical angular rotation speed ωel_flt after the filter process. The time constant required for calculating the electrical angular speed ωel_flt after filtering is determined from the time constant required for calculating the mechanical angular speed ωmc_flt. For example, the step response performance of the rotational speed control in the rotational speed control When the regulation is a time constant of 100 [ms], it is desirable that the time constant required for the calculation of the mechanical angular speed ωmc_flt is 1/10 or less, that is, 10 [ms] or less. This is because the change of the mechanical angular speed ωmc_flt that changes with a time constant of 100 [ms] during step response can be captured.

The operation and effect of the second embodiment will be described below.
If the step response performance regulation in the rotational speed control is set to a time constant of 100 [ms], the time constant of the first-order lag filter 246 is determined to be 10 [ms], the cutoff frequency is determined to be 100 [rad / s], and the electrical angular rotational speed ωel Assuming that the attenuation necessary for error reduction is 10 [%] as in the first embodiment, the first-order lag filter 246 of the cutoff frequency 100 [rad / s] is 1000 [rad / s] ≈159 [Hz]. Since the attenuation amount is 10 [%] in FIG. 5, the motor angular speed ωel included in the electrical angular rotational speed ωel has an error of the electrical angular rotational speed ωel without a notch filter function at a motor rotational speed exceeding 159 [Hz]. It can be reduced to 10 [%].

  Assuming that the conditions shown in FIG. 4 are satisfied, that is, the number of pole pairs (PP) of the motor 15 is 8, and the rotation speed of the motor 15 is 1500 [rpm], the electrical angle rotation speed is 12000 [rpm] (= 1500 (rpm) × 8 ( PP))). When the axial rotation angle (X) = 4 of the resolver 16 is set to 4 and the frequency of the error of θsns is twice the rotational frequency of the resolver electrical angle as shown in FIG. First, the motor electrical angular frequency is 159 [Hz] (= 159 [Hz] / 2) × 8 (P.P.) / 4 (X). Therefore, the motor rotation speed is 1193 [rpm] (= 159 [Hz] × 60 [rpm] / 8 (P.P.)).

  In order to appropriately exhibit the effect of the notch filter function, it is necessary to operate the notch filter function at a frequency at least 10 times the error frequency of the electrical angular rotation speed ωel to be reduced. Therefore, the notch filter function may be operated at a frequency of at least 1590 [Hz] = 629 [μs] with respect to the frequency 159 [Hz], and the notch filter function may be invalidated at a motor speed higher than this.

  On the other hand, when the first-order lag filter 246 is not used, it is necessary to increase the operating frequency of the notch filter function according to the upper limit value of the motor rotation speed. That is, by combining the first-order lag filter 246 and the notch filter, it is possible to achieve a 10% attenuation of the rotation speed error over the entire motor rotation speed, and to obtain a frequency value determined by the motor rotation speed and the time constant of the first-order lag filter 246. Since the operating frequency of the notch filter function can be lowered, there is an effect that an increase in calculation load of the motor control device 20 can be suppressed.

  FIG. 6 shows the gain characteristics of the filter combining the first-order lag filter and the notch filter function. As shown in FIG. 6, when the electrical angular rotational speed ωel is 100 [rad / s] or more, the attenuation amount of the notch filter function is adjusted according to the value of the electrical angular rotational speed ωel, and the first-order lag filter 246 and the notch filter function The attenuation may be set to the target value by both filters. The cut-off frequency of the notch filter is variable depending on the electrical angular rotation speed ωel.

  As mentioned above, the effect at the time of the rotational speed control has been described. When the time constant required for the calculation of the electrical angular rotational speed ωel_flt after the filter processing is specified also in the torque control, the notch filter function and the low-pass filter are combined. A similar effect can be obtained.

(Modification)
The present invention can be implemented by modifying the first and second embodiments described above as follows.

(1) Although the resolver 16 has been described as an example of the angle detector, any angle detector having the same characteristics as the resolver 16 can be implemented in the same manner.

(2) In the second embodiment, the filter unit 24 obtains the cut-off frequency by doubling the obtained electrical angle rotation frequency of the resolver 16 by the circuit 242 for obtaining the electrical angle rotation frequency of the resolver 16 by Expression 2. A circuit 243 is provided. However, as in the first embodiment, when the angle error of the resolver 16 has a plurality of frequency components that are n times the electrical angular rotation frequency, the filter unit 24 sets the frequency obtained by multiplying the electrical angular rotational frequency by n. The cut-off frequency for the notch filter function. For example, when the angular error has frequency components that are 1 and 4 times the electrical angular rotation frequency of the resolver 16, the circuit 244 for obtaining a frequency obtained by multiplying the electrical angular rotation frequency of the resolver 16 by 1 and the electrical angular rotation of the resolver 16 A circuit 245 for obtaining a frequency obtained by multiplying the frequency by four is added as a cutoff frequency of the notch filter function.

According to the embodiment described above, the following operational effects can be obtained.
(1) The motor control device 20 is based on the motor electrical angular rotational speed calculation unit 23 that calculates the motor electrical angular rotational speed based on the detection angle of the resolver 16 that detects the rotational angle of the motor 15, and the motor electrical angular rotational speed. A filter unit 24 having a notch filter function for changing the frequency to be cut off and outputting the motor electrical angular rotation speed after the filter, and the current of the motor 15 based on the motor electrical angular rotation speed and the torque command after the filter And a current control unit 30 for controlling. Therefore, the influence of the angle error of the angle detector such as the resolver 16 can be reduced, and a more accurate motor rotation speed can be obtained.

  The present invention is not limited to the above-described embodiment, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention as long as the characteristics of the present invention are not impaired. It is. Moreover, it is good also as a structure which combined the above-mentioned embodiment and a some modification.

DESCRIPTION OF SYMBOLS 10 DC power supply 11 Contactor 12 DC voltage sensor 13 Inverter 14 Motor current sensor 15 Motor 16 Resolver 20 Motor control device 21 Electrical angle conversion part 22 Motor electrical angle calculation part 23 Motor electrical angle rotation speed calculation part 24 Filter part 25 Pole logarithm calculation part 26 Communication Unit 27 Rotational Speed Control Unit 28 Pre-Limit Torque Selection Unit 29 Torque Limiting Unit 30 Current Control Unit 31 PWM Generation Unit 50 External Device

Claims (7)

Based on the detection angle of the angle detector that detects the rotation angle of the motor, a rotation speed calculation unit that calculates the motor electrical angle rotation speed,
A filter unit that has a notch filter function to vary the frequency to be cut off based on the motor electrical angular rotation speed, and that outputs the motor electrical angular rotation speed after the filter;
A current control unit for controlling the current of the motor based on the motor electrical angular rotation speed and the torque command after the filter ;
The filter unit further has a low-pass filter function for attenuating a frequency equal to or higher than a predetermined cutoff frequency, and performs a filter process on the motor electrical angular rotation speed using the notch filter function and the low-pass filter function,
The motor control device according to claim 1, wherein the filter unit invalidates the notch filter function when the motor electrical angle rotation number is equal to or greater than a threshold value . The motor control device according to claim 1,
The motor control apparatus according to claim 1, wherein the threshold value is a rotation speed corresponding to a frequency at which an attenuation amount by the low-pass filter function becomes a predetermined required attenuation amount. The motor control device according to claim 1 or 2,
The motor control device, wherein the filter unit operates the notch filter function at an operation frequency equal to or less than N times the motor electrical angular frequency corresponding to the threshold (N is a predetermined value of 10 or more). In the motor control device according to any one of claims 1 to 3,
When the motor electrical angle rotation number is equal to or greater than a value corresponding to the cut-off frequency, the filter unit is configured so that an attenuation amount combining the notch filter function and the low-pass filter function becomes a predetermined target value. A motor control device that adjusts an attenuation amount of a notch filter function. In the motor control device according to any one of claims 1 to 4 ,
The said filter part determines the said frequency which should be cut off based on the value according to the said motor electrical angle rotation speed and the characteristic of the said angle detector, The motor control apparatus characterized by the above-mentioned. The motor control device according to claim 5 ,
The rotational speed calculation unit obtains a motor electrical angle of the motor based on a detection angle of the angle detector, further obtains the motor electrical angle rotational speed based on the motor electrical angle,
The filter unit obtains an electrical angle rotation frequency of the angle detector based on the motor electrical angle rotation number, the number of pole pairs of the motor, and an angle multiplier of the angle detector, and an angle error of the angle detector is determined. When having a frequency component of n times the electrical angular rotation frequency, the motor control device characterized in that a frequency obtained by multiplying the electrical angular rotation frequency by n is set as a cutoff frequency of the notch filter function. The motor control device according to claim 6 ,
When the angle error of the angle detector includes a plurality of frequency components that are n times the electrical angular rotation frequency, the filter unit uses the frequency obtained by multiplying the electrical angular rotation frequency by n as the cutoff frequency of the notch filter function. A motor control device.

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