JP2013132200A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor controller capable of achieving weak magnetic flux control with high precision and high response.SOLUTION: The motor controller includes: a feedback control calculation section 203 that calculates a driving value; a driving phase setting section 211 that sets a driving phase value; a motor drive section 209 that drives energization of a motor 210 on the basis of the driving value and the driving phase value, and a spark advance control section 213 that calculates a spark advance value on the basis of a difference value between the driving value and a predetermined output limit reference value and sets the spark advance value at the driving phase setting section 211. Weak magnetic flux control is performed based on the spark advance value set by the spark advance control section 213.

Description

  The present invention relates to a motor control device that controls the rotational position, rotational speed, or output torque of a motor, mainly a brushless motor.

  When controlling the rotational position, rotational speed or output torque of the motor in a situation where the power supply voltage is limited, a saturation phenomenon occurs because the induced voltage of the motor becomes high especially in the high-speed rotation region, and the rotational speed cannot be increased. Or, problems such as a decrease in output torque generally occur. In order to avoid this state, conventionally, a magnetic flux weakening process has been proposed that detects the saturation state of the drive output of the motor and operates the phase of driving the motor to enable driving up to higher speed rotation. (For example, refer to Patent Document 1).

  FIG. 12 is a block diagram showing a configuration equivalent to the conventional motor control device described in Patent Document 1. In FIG. In FIG. 12, since the phase correction unit 121 and the input signal to the phase correction unit 121 are exactly the same as those of the motor control device shown in FIG. 1 to be described later, detailed description is omitted and only the phase correction unit 121 will be described. The energization drive value output from the feedback control calculation unit 203 is input to the phase correction unit 121 and the phase correction value is set, and then the phase correction value is set in the drive phase setting unit 211.

  A specific configuration of the phase correction unit 121 is shown in FIG. In FIG. 13, the phase correction value output from the phase correction unit 121 is stored in the phase correction value storage unit 131. The phase correction value and the energization drive value are input to the phase correction determination unit 133 to determine whether to perform the magnetic flux weakening control and whether to increase or decrease the phase, and the first switching unit 136 and the second switching unit. The operation of 137 is performed. Further, the phase correction addition value is stored as a unit for increasing or decreasing the phase. The sign inversion unit 135 outputs a value obtained by inverting the sign of the phase correction addition value 134. The first switching unit 136 selects and outputs the value of the phase correction addition value 134 and the value of the sign inverting unit 135. The second switching unit 137 selects whether or not the value selected by the first switching unit 136 is added by the adding unit 132. The output value of the second switching unit 137 is added to the value of the phase correction value storage unit 131 in the addition unit 132 and output to the outside as an updated phase correction value, and at the same time, stored in the phase correction value storage unit 131. The

  FIG. 14 is a waveform diagram showing changes in the rotational speed of a conventional motor.

  FIG. 14A shows a waveform diagram when the command rotational speed is changed stepwise. FIG. 14B shows a response waveform diagram of the rotation speed of the motor 210 when such a speed command is input to the motor control device shown in FIG. For example, if the rotation speed of the motor 210 is saturated at 3500 [r / min], the phase correction determination unit 133 determines that the flux-weakening control is necessary in the region of higher rotation speed. Therefore, for a certain period after the rotation speed exceeds 3500 [r / min], the value of the phase correction addition value 134 is added to the value of the phase correction value storage unit 131, and the value of the phase correction value increases. As a result, the effect of the magnetic flux weakening control is exhibited, and the rotational speed of the motor can be increased to a rotational speed of 6000 [r / min] as shown in FIG.

JP 2004-180489 A

  However, in the above-described conventional configuration, after the increase / decrease direction of the phase for driving the motor is determined, the increase / decrease is performed with a phase value of a predetermined magnitude step by step. For this reason, in the conventional configuration, if the phase value of one step is large, the adjustment accuracy is inferior. Conversely, if the phase value of one step is small, the adjustment accuracy is good, but it takes time to adjust to the optimum phase. Therefore, there was a problem that the responsiveness deteriorated.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a motor control device that realizes magnetic flux weakening control with high accuracy and good response.

  In order to achieve such an object, the motor control device of the present invention is a motor control device that performs feedback control of any of the speed, position, and torque of the motor. The motor control device calculates a drive amount for driving the motor and outputs a drive value as a feedback control calculation unit, a drive phase setting unit for outputting a phase for driving the motor as a drive phase value, a drive value and a drive phase A motor drive unit that energizes the motor based on the value, an advance value that advances the drive phase of the motor based on a difference value between the drive value and a predetermined output limit reference value, and the advance value is input to the drive phase setting unit. And an advance angle control unit to be set. And this motor control apparatus is the structure which performs a flux-weakening control based on the advance value which the advance angle control part set.

  With such a configuration, when the motor drive output is saturated, the process of automatically setting the advance value that advances the motor drive phase according to the degree of saturation is automatically performed. Good magnetic flux weakening control can be realized.

  In the motor control device of the present invention, the advance angle control unit performs a proportional integration operation on the difference value between the drive value and the output limit reference value, and a value based on the proportional integration operation is used as an advance value. .

  With such a configuration, the flux weakening control can function smoothly at the limit of the motor drive output, and the flux weakening control can be performed with higher accuracy.

  The motor control device of the present invention further includes a limiter that limits the upper limit of the drive value to a predetermined limit value. The motor control device is configured to supply the drive value to the advance angle control unit, to supply the output value of the limiter to the motor drive unit, and to set the drive output reference value as the limit value of the limiter.

  With such a configuration, the flux-weakening control is made to function at the limit of the motor drive output, and the efficiency and responsiveness for driving the motor can be kept good.

  Furthermore, the motor control device of the present invention further includes an offset phase table that records an offset value of the drive phase that maximizes the output torque of the motor according to the rotational speed of the motor. The motor control device is configured to add the value of the offset phase table corresponding to the number of rotations of the motor and the advance value set by the advance angle control unit, and set it as the drive phase value in the drive phase setting unit.

  With such a configuration, the motor can be efficiently driven with an optimum phase in any rotational speed region.

  In addition, the motor control device of the present invention detects a current value flowing in the motor or a circuit that drives the motor, and limits a command value from the outside based on a difference value between the current value and a predetermined current limit value. A limiting unit is further provided.

  With such a configuration, even when the current flowing through the motor or the circuit that drives the motor is increased by the magnetic flux weakening control, it is possible to automatically reduce an external command and avoid an overcurrent.

  The motor control device according to the present invention can be realized by a relatively simple calculation means such as a microcomputer, and can realize weak flux control with high accuracy and excellent responsiveness by a relatively simple calculation process. In addition, the motor driving efficiency can be maintained with good characteristics, and the motor can be driven with an optimum phase at any rotational speed. Furthermore, even when the current flowing through the motor becomes large, the command value from the outside can be appropriately reduced, and an operation for avoiding overcurrent is possible. Thus, the motor control device of the present invention can provide a motor control device that realizes magnetic flux weakening control with high accuracy and good response.

Block diagram of motor control apparatus according to Embodiment 1 of the present invention Same as above, block diagram of advance control unit of motor control device The figure which shows the operation example of a motor control apparatus similarly Same as above, characteristic diagram of command rotation speed vs. advance angle value in motor control device Same as above, waveform diagram showing change in motor rotation speed between motor control device and comparative example Block diagram of a motor control device in Embodiment 2 of the present invention Same as above, characteristics of offset value and advance value in motor controller Block diagram of motor control apparatus according to Embodiment 3 of the present invention Same as above, block diagram of command control unit in motor control device Characteristic chart showing command rotational speed versus motor current in Embodiment 1 of the present invention The characteristic view which shows the command rotational speed versus motor current in Embodiment 3 of this invention Block diagram of a conventional motor control device Block diagram of phase correction unit of conventional motor control device Waveform diagram showing changes in motor speed in a conventional motor controller

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a motor control device 200 according to Embodiment 1 of the present invention.

  In FIG. 1, the motor control device 200 drives and controls a motor 210. The motor 210 holds, for example, a stator in which a winding (not shown) is wound around an iron core and the like, and a permanent magnet (not shown) as a magnetic pole with a rotating shaft as a center, and can rotate freely facing the stator. And a disposed rotor. By applying three-phase AC power, for example, U-phase, V-phase, and W-phase, from the motor control device 200 to this winding, the motor 210 is driven to rotate, and the rotor rotates. Further, the motor 210 is provided with a hall sensor 212 for detecting the rotor position, and the hall sensor 212 outputs a signal that changes according to the magnetic pole position of the motor 210. A signal output from the hall sensor 212 is supplied to the speed detection unit 201 and the drive phase setting unit 211.

  The speed detection unit 201 detects the rotation speed of the motor 210 based on the signal from the hall sensor 212. On the other hand, the motor control device 200 is notified of a speed command for commanding the rotation speed of the motor 210 from the outside as a rotation command. The speed error detection unit 202 calculates and outputs a difference between values of the rotation speed of the motor 210 output from the speed detection unit 201 and a speed command input from the outside as a speed error. This speed error is notified to the feedback control calculation unit 203.

  The feedback control calculation unit 203 calculates a motor drive amount based on the input speed error and outputs it as a motor drive output. The feedback control calculation unit 203 includes a proportional gain multiplication unit 204, an integration processing unit 205, an integration gain multiplication unit 206, an addition unit 207, and a limiter 208. The speed error input to the feedback control calculation unit 203 is multiplied by a predetermined proportional gain in the proportional gain multiplication unit 204, and the result is output. On the other hand, the speed error is also input to the integration processing unit 205, and is integrated and output at a predetermined cycle. The output of the integration processing unit 205 is input to the integration gain multiplication unit 206, multiplied by a predetermined integration gain, and the result is output. Outputs of the proportional gain multiplication unit 204 and the integral gain multiplication unit 206 are added by the addition unit 207, and the added value is output as a drive value to the limiter 208 and the advance angle control unit 213. In addition, with such a configuration, proportional integral calculation is performed on the input speed error, and a drive value is calculated by this proportional integral calculation. The limiter 208 limits and outputs a predetermined limit value as an upper limit value for the input drive value. That is, the limiter 208 outputs the drive value as a drive output when the drive value is less than or equal to the limit value, and outputs the limit value as a drive output when the drive value exceeds the limit value. The value of the drive output output from the limiter 208 in this way is supplied to the motor drive unit 209 as an energization drive value.

  Further, the advance angle control unit 213 receives the drive value output from the adder unit 207, calculates an advance value by calculation based on this drive value, and sets the calculated advance value in the drive phase setting unit 211. To do.

  The motor driving unit 209 drives the motor 210 according to the energization driving value input from the feedback control calculation unit 203. At this time, the drive phase setting unit 211 generates a drive phase value indicating the drive phase of the motor drive unit 209 according to the output signal of the hall sensor 212 and the advance value output from the advance angle control unit 213, and this drive phase value Is set in the motor drive unit 209. More specifically, the motor drive unit 209 includes a PWM (Pulse Width Modulation) signal generation circuit and an inverter circuit. The PWM signal generation circuit generates a pulse signal obtained by performing pulse width modulation on a waveform having an amplitude corresponding to the energization drive value from the feedback control calculation unit 203. For example, when the motor 210 is driven in a sine wave, this waveform is a sine wave. The output phase of this waveform is set by the drive phase value from the drive phase setting unit 211. The inverter circuit has a plurality of switching elements, and these switching elements are ON / OFF controlled by a pulse signal from the PWM signal generation circuit, thereby converting DC power into AC power having the above waveform. Then, AC power from the inverter circuit is applied to the winding of the motor 210, and the winding is energized. By such an operation of the motor drive unit 209, the winding of the motor 210 is energized with an energization amount corresponding to the energization drive value.

  As described above, in the present embodiment, the speed error detection unit 202 calculates the speed error between the speed command commanded from the outside and the rotation speed detected by the speed detection unit 201, and the feedback control calculation unit 203 The energization drive value based on the error is output to the motor drive unit 209, and the motor drive unit 209 energizes and drives the windings of the motor 210 according to the energization drive value. With this configuration, a major control loop is formed for feedback control of the energization drive amount to the winding. Furthermore, in the present embodiment, the advance angle control unit 213 calculates an advance value based on the drive value calculated by the feedback control calculation unit 203, and the motor drive unit 209 has a phase corresponding to the advance value. The winding of the motor 210 is configured to be energized. With this configuration, a minor control loop is formed that feedback-controls the phase amount of energization to the winding. In the present embodiment, feedback control is performed so that the rotational speed of the motor 210 follows the speed command by such a configuration of the major control loop and the minor control loop.

  Next, a detailed configuration of the minor control loop including the advance angle control unit 213 will be described.

  FIG. 2 is a block diagram showing a detailed configuration of the advance angle control unit 213. As shown in FIG. 2, the advance angle control unit 213 includes a saturation detection unit 101 and an advance angle calculation unit 102.

  In FIG. 2, the drive value calculated by the feedback control calculation unit 203 is supplied to the saturation detection unit 101. In the saturation detection unit 101, an output limit reference value is set in advance. The saturation detection unit 101 calculates and outputs a difference value between the drive value and the output limit reference value as an output deviation value. Here, the output limit reference value is set so that the output limit reference value is equal to the limit value of the limiter 208. Further, in the present embodiment, the output deviation value calculated in this way is used as a value indicating the degree of saturation in motor driving, that is, the degree of saturation. Specifically, saturation is reached when the drive value becomes equal to the output limit reference value, and the saturation increases as the output deviation value increases from zero. In other words, saturation is reached when the drive value becomes equal to the limit value of the limiter 208, and the saturation level increases as the drive value increases with respect to the limit value.

  The output deviation value output from the saturation detection unit 101 is input to the advance angle calculation unit 102, and the advance angle calculation unit 102 calculates and outputs an advance value based on the input output deviation value. The advance angle calculation unit 102 includes a proportional gain multiplication unit 103, an integration processing unit 104, an integration gain multiplication unit 105, an addition unit 106, and a limiter 107. The output deviation value input to the advance angle calculation unit 102 is multiplied by a predetermined proportional gain in the proportional gain multiplication unit 103, and the result is output. On the other hand, the output deviation value is also input to the integration processing unit 104 and is integrated and output at a predetermined period. The output of the integration processing unit 104 is input to the integration gain multiplication unit 105, multiplied by a predetermined integration gain, and the result is output. Outputs of the proportional gain multiplication unit 103 and the integral gain multiplication unit 105 are added by the addition unit 106, and this addition value is output to the limiter 107. Further, with such a configuration, proportional-integral calculation is performed on the input output deviation value. The limiter 107 limits and outputs a predetermined limit value as an upper limit for the input addition value. That is, the limiter 107 outputs the added value as an advance value when the added value is less than or equal to the limit value, and outputs the limit value as the advanced value when the added value exceeds the limit value. The lower limit value is also set in the limiter 107, and in this embodiment, the lower limit value is set to 0 and a negative advance value is not output.

  In this manner, the advance angle control unit 213 detects the degree of saturation in the motor drive as a difference value between the drive value and the drive output reference value. The advance angle control unit 213 calculates an advance value that advances the drive phase of the motor 210 based on the output deviation value that is the difference value, and sets the calculated advance value in the drive phase setting unit 211. Further, although details will be described below, in the present embodiment, the flux-weakening control is performed by controlling the phase in the motor drive based on the advance value.

  Next, the operation | movement and effect | action are demonstrated below about the motor control apparatus 200 comprised as mentioned above.

  The motor control device 200 shown in FIG. 1 is configured to receive a speed command from the outside and perform feedback control such that the rotational speed of the speed command matches the rotational speed of the motor 210. Although the speed control of the motor 210 can be performed without the advance angle control unit 213, the advance value set in the drive phase setting unit 211 is a fixed value. On the other hand, in the present embodiment, the advance angle control unit 213 shown in FIG. 2 is added to enable the magnetic flux weakening control corresponding to the degree of saturation in the motor drive.

  As shown in FIG. 1, the drive value before being limited by the limiter 208 is input to the saturation detection unit 101 of the advance angle control unit 213, and the advance value output from the advance angle calculation unit 102 is input to the drive phase setting unit 211. Entered. As a result, a minor control loop in which the drive value is input to the drive phase setting unit 211 via the advance angle control unit 213 is configured. With the minor control loop configured as described above, the advance value is automatically set to the optimum value in accordance with the saturation level of the drive output.

  FIG. 3 is a diagram illustrating an operation example of the motor control device 200 configured as described above. Next, the operation of the motor control device 200 configured as described above will be described with reference to FIG.

  The motor drive unit 209 drives the motor 210 by PWM, and sets the upper limit of the PWM duty to 98 [%]. That is, the drive value of the feedback control calculation unit 203 is limited to an upper limit of 98 [%] by the limiter 208. When the speed control operation is performed in this state, the value of the energization drive output [%] corresponding to the energization drive output value with respect to the command rotational speed [r / min] as the speed command is as shown in FIG. To change. That is, as the command rotational speed [r / min] changes from low speed to high speed, the value of the energization drive output [%] increases, reaches the upper limit of 98 [%] at 3500 [r / min], and is saturated. It becomes. If the advance angle control unit 213 shown in FIG. 1 is not equipped, that is, if it is configured only by the major control loop, the upper limit of the rotation speed of the motor 210 is 3500 [r / min], and the rotation speed is further increased. It is impossible to increase the number. On the other hand, when the advance angle control unit 213 shown in FIG. 1 is equipped as in the present embodiment, even if the energization drive output exceeds the upper limit value 98 [%], the advance angle control unit 213 Since an unrestricted drive value is supplied, the advance value is increased until the saturation of the energization drive output is eliminated. When the advance angle value increases, the induced voltage of the motor 210 decreases, so that the operation in a direction in which the degree of saturation of the energization drive output decreases. As described above, since the operation for increasing the advance angle value and the operation for decreasing the saturation level of the energized drive output are balanced, the operation automatically converges toward the advance value at which the saturation of the drive output is eliminated. .

  In this case, even when the command rotational speed increases exceeding 3500 [r / min], the advance value [deg] automatically increases as shown in FIG. An operation that rises following the rotational speed is obtained. Even when the upper limit value of the advance angle value is limited to 40 [deg], it is possible to follow up to a rotational speed of 6000 [r / min]. Conversely, when the command rotational speed decreases from high speed to low speed, the advance value [deg] automatically decreases. In this way, since the advance value automatically converges toward the optimum value at the operating point in any state, the optimum motor control operation is always possible regardless of the change in the command rotational speed.

  In addition, such an operation of automatically increasing the advance value in accordance with the degree of saturation of the energization drive output is effective even when the power supply voltage fluctuates. The operation when the power supply voltage deviates from the standard voltage value will be described with reference to FIG.

  FIG. 4 shows a case where the power supply voltage is 2 [V] lower than the standard voltage value (indicated by −2 V), 2 [V] higher (indicated by +2 V), and a standard voltage value (indicated by 0 V). The characteristics of the command rotational speed [r / min] versus the advance angle value [deg] are shown for the three types. As can be seen from this figure, when the power supply voltage is low, the energization drive output is saturated and the rotational speed at which the advance value starts to increase is low. FIG. 4 shows an example in which when the power supply voltage is 2 [V] lower, the rotation speed at which the advance value starts to increase is 3000 [r / min]. On the other hand, when the power supply voltage is high, the rotation speed at which the advance angle value starts to increase due to saturation of the energization drive output increases. FIG. 4 shows an example in which when the power supply voltage is 2 [V] higher, the rotational speed at which the advance value starts to increase is 4000 [r / min]. Even when the power supply voltage fluctuates in this way, the advance value automatically converges to the optimum value according to the saturation level of the drive output, so that the optimum motor control operation can always be performed regardless of changes in the command rotational speed. It becomes possible.

  In the present embodiment, the limiter 208 is provided, and the upper limit of the PWM duty can be set by this. Therefore, the limiter 208 is preferably arranged, but the limiter 208 may not be arranged. In this case, an output limit reference value corresponding to a drive value that reaches saturation in motor drive may be set as the output limit reference value of the saturation detection unit 101, and flux weakening control can be performed.

  Next, the response of the rotational speed of the motor 210 when the command rotational speed changes in a step shape will be described. FIGS. 5A to 5C show examples of changes in the rotational speed with respect to time on the horizontal axis. FIG. 5A shows the change in the command rotational speed of the speed command, which increases to 6000 [r / min] at time 100 [msec] and 1000 [r / min at time 250 [msec]. min]. As a comparative example, the motor control device that is not equipped with the advance angle control unit 213 becomes saturated at 3500 [r / min] as described above. The response is as follows. On the other hand, in the motor control device equipped with the advance angle control unit 213 as in the present embodiment, the motor can be rotated even at 6000 [r / min], so the command as shown in FIG. It is possible to follow the rotational speed. In addition, since the advance angle value is calculated according to the saturation level of the energization drive output in the present embodiment, high-speed response without causing a large delay as shown in FIG. 14B in the description of the prior art. Indicates.

  As described above, the flux-weakening control can be performed smoothly in the limit region of the energization drive output, and good response characteristics can be obtained because of the configuration of the present invention. A good operation may not be realized.

  As described above, in the present embodiment, the feedback control calculation unit 203 that controls any of the speed, position, and torque of the motor 210, and the difference value between the drive value that is the output and the predetermined output restriction reference value. Is provided with an advance angle control unit 213 that calculates and sets an advance value that advances the drive phase of the motor. Based on the advance value calculated in this way, the flux weakening control is performed according to the saturation of the drive output of the motor 210. For this reason, the advance value automatically converges toward the optimum value at the operating point, and the optimum motor control operation is always possible regardless of the change in the command rotational speed. Thus, according to the configuration of the present embodiment, it is possible to realize the flux-weakening control with high accuracy and good response.

  In this embodiment, a limiter 208 that limits the upper limit of the drive output of the motor 210 is provided, and the drive value is supplied to the advance angle control unit 213 and the output value of the limiter 208 is supplied to the motor drive unit 209. Yes. The limit value of the limiter 208 is set as a predetermined output limit reference value in the advance angle control unit 213. By adopting such a configuration, it is possible to realize weak flux control with good responsiveness and efficiency.

(Embodiment 2)
FIG. 6 is a block diagram showing a configuration of motor control device 600 according to Embodiment 2 of the present invention. The difference from the first embodiment shown in FIG. 1 is that the motor control device 600 further includes an offset phase table 601 and an adding unit 602. The configuration of the motor control device 600 is otherwise the same as that shown in FIG. 1, and detailed description of the same components will be omitted.

  In general, the drive phase in which the torque is most generated by the winding inductance or the like varies depending on the rotational speed of the motor, and it is necessary to increase the advance value as the rotational speed increases. For this reason, in the present embodiment, the magnetic flux weakening control is performed using the advance value as in the first embodiment, and a suitable torque is obtained using the advance value.

  In FIG. 6, an offset phase table 601 is a table that stores the offset value of the advance angle value according to the rotational speed. The rotation speed is notified from the speed detection unit 201 to the offset phase table 601, and the offset phase table 601 outputs an output value that is an offset value of an advance value according to the rotation speed. The output value of the offset phase table 601 is added to the output value of the advance angle control unit 213 by the adding unit 602 and set as the advance value in the drive phase setting unit 211.

  FIG. 7 is a diagram illustrating an example of the offset value and the advance value set in the drive phase setting unit 211. FIG. 7A shows an example of the offset value of the advance angle value, and FIG. 7B shows an example of the advance value set in the drive phase setting unit 211. Here, the offset value of the advance value shown in FIG. 7 (a) is a value obtained by storing the value of the drive phase at which the motor 210 produces the maximum torque as the offset value. It is different from the advance value of.

  In the motor control device 600 configured as described above, when the speed control operation is performed in the same manner as in the first embodiment, the value set as the advance value in the drive phase setting unit 211 results in FIG. ). In this case, the energization drive output is saturated at a rotational speed of 4000 [r / min] or more, and the magnetic flux weakening control operation is performed. However, when compared with the change in the advance value shown in FIG. 3, it is 4000 [r / min] or less. The advance value is slightly larger at the number of rotations. For this reason, when compared with the configuration of the first embodiment, it can be seen that the configuration of the present embodiment increases the torque in the low speed region and improves the efficiency.

  As described above, the present embodiment further includes the offset phase table 601 that records the offset value of the drive phase that maximizes the output torque of the motor 210 according to the rotation speed of the motor 210. By adding the value of the offset phase table 601 corresponding to the number of rotations and the advance value set by the advance angle control unit 213 and setting it as the drive phase, the same operation as in the first embodiment is possible. The effect of obtaining more excellent driving efficiency can be exhibited.

(Embodiment 3)
FIG. 8 is a block diagram showing a configuration of a motor control device 800 according to Embodiment 3 of the present invention. The difference from Embodiment 1 shown in FIG. 1 is that motor control device 800 further includes a current detection unit 801, a command control unit 802, a subtraction unit 803, and a command limiting unit 804. The configuration of the motor control device 800 is otherwise the same as that shown in FIG. 1, and detailed description of the same components will be omitted.

  In FIG. 8, the current detection unit 801 detects the current flowing through the motor 210 and outputs the detected current value to the command control unit 802. The command control unit 802 outputs a command limit value so that the current value from the current detection unit 801 does not exceed a predetermined limit value. The command limit value is calculated by the subtraction unit 803 as a difference value from the speed command value, and the difference value is set as a limit value of the command limit unit 804 that is a limiter. The value of the speed command is input to the speed error detecting unit 202 via the command limiting unit 804, and is limited to the set limit value in this process. That is, the command limiter 804 outputs the speed command value when the speed command value is less than or equal to the limit value, and outputs the limit value when the speed command value exceeds the limit value.

  FIG. 9 is a block diagram showing a specific configuration of the command control unit 802. The command control unit 802 includes an overcurrent detection unit 901 and a command limit calculation unit 902. The overcurrent detection unit 901 is preset with a current limit reference value. In the overcurrent detection unit 901, a difference value between the input current value and the current limit reference value is calculated as an overcurrent deviation value. This overcurrent deviation value is input to the command limit calculation unit 902, and the command limit value is output. The overcurrent deviation value is obtained by multiplying a value obtained by multiplying the proportional gain by the proportional gain multiplying unit 903 and a value multiplied by the integral gain by the integral gain multiplying unit 905 via the integral processing unit 904 in the command limit calculating unit 902. Are added by the adding unit 906. That is, proportional integral calculation is performed on the overcurrent deviation value, and the result is output as an added value. This added value is output as a command limit value via the limiter 907. The limiter 907 has the same configuration as that of the limiter 208 and the like. The limiter 907 limits and outputs a predetermined limit value as an upper limit value with respect to the input addition value.

  In the motor control apparatus 800 configured as described above, the speed command value is limited so that the current flowing through the motor 210 does not exceed a predetermined limit value, that is, the current limit reference value.

  FIG. 10 is a diagram illustrating an example of the value of the motor current with respect to the command rotational speed when the power supply voltage fluctuates as a comparative example. FIG. 11 is a diagram showing an example of the value of the motor current with respect to the command rotational speed when the power supply voltage fluctuates in the present embodiment. 10 and 11, the case where the power supply voltage is 2 [V] lower than the standard voltage value is indicated by −2V, the case where it is 2 [V] higher is indicated by + 2V, and the case of the standard voltage value is indicated by 0V. .

  In particular, when the power supply voltage is low, the increase in motor current becomes significant, and the load on the circuit that drives the motor may become excessive in the high-speed rotation region. In such a case, for example, when the current limit reference value is set to 1 [A], the value of the motor current with respect to the command rotational speed is limited to 1 [A] or less, which is the current limit reference value, as shown in FIG. The In the area where the motor current is limited, the motor speed does not follow the command speed, but it is possible to avoid damage to the circuit that drives the motor due to overcurrent, which is below the current limit reference value. In the region, it is possible to increase the number of rotations that can be followed by the operation of flux-weakening control as in the first embodiment.

  As described above, in the present embodiment, the current value flowing in the motor 210 or the circuit that drives the motor 210 is detected, and the speed error detection unit is based on the difference value between the current value and the predetermined current limit reference value. By providing a command limiter 804 that limits the value of a speed command that is an external command value input to 202, a weak flux control operation can be performed in the same manner as in the first embodiment, and at the same time, the motor is caused by an overcurrent. It is possible to avoid damaging the circuitry that drives 210.

  In the first to third embodiments, the case where the speed of the motor is controlled has been described. However, the same advance angle as described above also applies to the configuration in which the rotational position of the motor or the output torque of the motor is controlled by feedback control. By adding a control unit, it is possible to control the magnetic flux weakening, and the same effect as described above can be obtained.

  As described above, the motor control device of the present invention is a motor control device that feedback-controls any of the speed, position, and torque of the motor, and includes a feedback control calculation unit that outputs a drive value, and the drive value and a predetermined value. An advance angle control unit that calculates and sets an advance value for advancing the motor drive phase based on a difference value from the output limit reference value. Based on the advance value calculated in this way, the flux weakening control is performed in accordance with the saturation level of the drive output of the motor. For this reason, the advance value automatically converges toward the optimum value at the operating point, and the optimum motor control operation is always possible regardless of the change in the command rotational speed. Therefore, according to the present invention, magnetic flux weakening control with high accuracy and good response can be realized.

  The present invention also includes a limiter that limits the upper limit of the motor drive output, inputs the drive value to the advance angle control unit, supplies the output value of the limiter to the motor drive unit, and sets the drive output reference value to the limiter. By setting the limit value, the magnetic flux weakening control with good responsiveness and efficiency is realized.

  As described above, the motor control device according to the present invention can realize the magnetic flux weakening control with high accuracy and good responsiveness by a relatively simple realization means, and particularly requires a high speed rotation and a high speed response. Alternatively, the application range can be expanded in applications where power supply voltage fluctuations are significant.

DESCRIPTION OF SYMBOLS 101 Saturation degree detection part 102 Advance angle calculating part 103 Proportional gain multiplication part 104 Integration processing part 105 Integral gain multiplication part 106 Adder part 107 Limiter 121 Phase correction part 131 Phase correction value storage part 132 Addition part 133 Phase correction determination part 134 Phase correction Addition value 135 Sign inversion unit 136 First switching unit 137 Second switching unit 201 Speed detection unit 202 Speed error detection unit 203 Feedback control calculation unit 204 Proportional gain multiplication unit 205 Integration processing unit 206 Integration gain multiplication unit 207 Addition unit 208 Limiter 209 Motor drive section 210 Motor 211 Drive phase setting section 212 Hall sensor 213 Advance angle control section 601 Offset phase table 602 Addition section 801 Current detection section 802 Command control section 803 Subtraction section 804 Command limit section 901 Overcurrent detection Part 902 command limit calculation unit 903 proportional gain multiplication section 904 integration processing unit 905 integral gain multiplication unit 906 adding unit 907 limiter

Claims (5)

A motor control device that performs feedback control of any of the speed, position, and torque of the motor,
Calculating a drive amount for driving the motor and outputting it as a drive value; a drive phase setting unit for outputting a phase for driving the motor as a drive phase value;
A motor drive unit for energizing and driving the motor based on the drive value and the drive phase value;
An advance angle controller that calculates an advance angle value that advances the drive phase of the motor based on a difference value between the drive value and a predetermined output restriction reference value, and sets the advance angle value in a drive phase setting unit;
A motor control device that performs flux-weakening control based on the advance value set by the advance controller. The advance angle control unit performs a proportional integration operation on the difference value between the drive value and the output restriction reference value, and sets a value based on the proportional integration operation as the advance value. Item 2. The motor control device according to Item 1. A limiter for limiting the upper limit of the drive value to a predetermined limit value;
While supplying the drive value to the advance angle control unit, supplying the output value of the limiter to the motor drive unit,
The motor control device according to claim 1, wherein the output limit reference value is set as a limit value of the limiter. An offset phase table that records an offset value of the drive phase such that the output torque of the motor is maximized according to the rotational speed of the motor;
A value of the offset phase table corresponding to the number of rotations of the motor and the advance value set by the advance angle control unit are added and set as the drive phase value in the drive phase setting unit. The motor control apparatus of any one of Claim 1 to 3. The apparatus further includes a command limiter that detects a current value flowing through the motor or a circuit that drives the motor and limits a command value from the outside based on a difference value between the current value and a predetermined current limit reference value. The motor control device according to claim 1, wherein:

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