JP2002165478A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor controller for estimating the rotor magnetic pole position or rotating angular velocity in order to improve, on the rear-time basis, estimation accuracy by compensating for change of motor constant due to temperature rise during operation, and to realize the stable motor drive system. SOLUTION: A motor constant compensating means compensates for the change of motor constant, using any one of a motor current or a motor voltage corresponding to an output signal of a steady-state determining means for determining whether the operating condition reaches the steady state. A position/ velocity estimating and calculating means estimates the magnetic pole position of a rotor or a rotational angular velocity, based on the motor constant and then outputs it to a PWM signal generating circuit. By using the estimation accuracy can be improved, using the compensated motor constant, and thereby highly accurate velocity and torque control can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device for estimating the position of a magnetic pole of a rotor or estimating a rotational angular velocity for control.

[0002]

2. Description of the Related Art A conventional motor control device will be described below. Generally, in a motor control device that estimates the magnetic pole position of the rotor or estimates the rotational angular velocity by 180-degree energization in which there is no non-energized section, the magnetic pole position or rotational angular velocity of the rotor is estimated based on the motor voltage equation. Estimation is being performed. For this reason, the motor constant changes due to a rise in temperature due to operation and the like, and the estimation accuracy is reduced, and it is difficult to realize highly accurate control of the motor.

Therefore, for example, Japanese Patent Application Laid-Open No. Hei 7 (1995) shown in FIG.
A motor control device disclosed in -67400 has been proposed. In FIG. 7, the main circuit includes a DC power supply 1,
An inverter 2 configured by connecting three sets of two switching elements connected in series and connected in parallel to each other and converting DC power into AC power, and a motor as an induction machine driven by the AC power converted by the inverter 2 3 is comprised.

On the other hand, in the control circuit, a vector for calculating an estimated value of the rotational angular velocity of the motor from the motor current detected by the current detector 4 composed of 4a, 4b and 4c provided in the main circuit and the current detection circuit 5 The control operation means 6 and the inverter 2 output from the vector control operation means 6
P that outputs a gate signal to each switching element of
And a WM signal generation circuit 7.

The temperature estimating means 8 calculates an estimated value of the rotational angular velocity output from the vector control calculating means 6.

[Outside 1] And the previous and previous values of the motor current output from the current detection circuit 5 to calculate the current and past losses due to copper loss and iron loss. Next,
The final temperature rise is calculated for each loss, and the current temperature is calculated by superimposing the respective temperature rises using the thermal constant output means 9 in consideration of the time delay due to the thermal time constant.

The resistance value estimating means 10 uses the current temperature output from the temperature estimating means 8 to output a resistance value based on a correspondence map between temperature and resistance. Next, the resistance value output from the resistance value estimating means 10 is input to the vector control calculating means 6 to estimate the rotational angular velocity.

[0007]

In such a conventional configuration, it is necessary to estimate the temperature in order to estimate the resistance value, and the circuit configuration becomes complicated as the number of operations increases, and the capacity of the arithmetic unit increases. There has been a problem in follow-up between the speed command and the estimated rotational angular velocity due to an increase in cost and an increase in calculation time. In addition, since only the resistance value of the induction machine is estimated and other types of motors are not targeted, not only lacks versatility but also does not take into account compensation for changes in other motor constants. There is a problem that it is difficult to perform speed and torque control.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and aims to improve the accuracy of position / speed estimation by compensating in real time for changes in motor constants due to a rise in temperature due to operation, thereby achieving a stable motor drive system. It is an object of the present invention to provide a motor control device capable of realizing the speed and torque control with high accuracy.

[0009]

According to the present invention, a magnetic pole position or a rotational angular velocity of a rotor is estimated based on a speed command or a torque command to a motor driven by an output of an inverter and a motor constant. Position / speed estimating means for outputting to the PWM signal generating means for controlling the inverter; motor constant compensating means for compensating for a change in the motor constant and outputting to the position / speed estimating means; and a control system for the motor Comprises a steady state determining means for determining whether or not has reached a steady state, wherein the motor constant compensation means,
A motor control device configured to compensate for a change in the motor constant using at least one of a current and a voltage of the motor in accordance with an output signal of the steady state determination unit.

According to the present invention, it is possible to compensate in real time for a change in motor constant due to a temperature rise or the like during operation, and to realize a stable motor drive system by improving the estimation accuracy.

According to a second aspect of the present invention, the motor constant compensating means switches the compensation mode depending on the state of the motor control system. In a steady state, the compensation mode is turned on to compensate for a change in the motor constant. 2. The motor control device according to claim 1, wherein the compensation mode is turned off to stop the compensation for the change in the motor constant, and the previous value of the motor constant is used.

According to the present invention, the stability of the motor drive system in a transient state can be ensured, and a stable motor drive system can be realized in all situations.

According to a third aspect of the present invention, the motor constant compensating means is provided with a compensation mode switching grace period before and after the compensation mode switching to prevent the motor constant compensation value from becoming discontinuous. The motor control device according to claim 2, further comprising a mode stabilization switching unit.

According to the present invention, it is possible to ensure control stability and to reduce noise and vibration associated with switching of the compensation mode, thereby realizing a more stable motor drive system.

According to a fourth aspect of the present invention, the motor constant compensating means calculates a true value of the motor constant from at least one of the motor current and the voltage from the voltage equation of the motor. A motor control device according to claim 3.

According to the present invention, the calculation can be performed by a microcomputer or the like without adding new hardware, and the motor constant can be directly compensated without estimating the temperature.

According to a fifth aspect of the present invention, there is provided a time measuring means for measuring an elapsed time from the start of operation of the motor, wherein the motor constant compensating means comprises a current of the motor and an elapsed time measured by the time measuring means. The motor according to any one of claims 1 to 3, further comprising: a data table that outputs a true value of the motor constant by inputting the data table and compensating for a change in the motor constant with reference to the data table. It is a control device.

According to the present invention, the operation time required for compensating for a change in the motor constant can be greatly reduced, and more accurate motor constant compensation can be realized.

According to a sixth aspect of the present invention, the steady state determining means is configured to determine at least one of a motor current detection value obtained from the motor current detecting means or an estimated rotational angular velocity derived by the position / speed estimating calculating means. The motor control device according to any one of claims 1 to 3, wherein it is determined whether a steady state has been reached.

According to the present invention, a steady state can be calculated by a microcomputer or the like without adding new hardware, and a steady state determination can be realized in an equivalent calculation time.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention according to claim 1 is an inverter for converting DC power into AC power and outputting the same, PWM signal generating means for controlling the output of the inverter by a PWM signal, and an output of the inverter. A motor current detecting means for detecting a current of a motor driven by the motor or a motor voltage detecting means for detecting a voltage of the motor, and a speed command or a torque command to the motor, and A position / speed estimating means for estimating the magnetic pole position or the rotational angular velocity of the rotor based on the constant and outputting the result to the PWM signal generating means; and compensating for a change in the motor constant and outputting to the position / speed estimating means. A motor constant compensating means; and a steady state determining means for determining whether a control system of the motor has reached a steady state. Motor constant compensation unit in accordance with an output signal of the steady state determining means, and a motor control apparatus adapted to compensate for changes in the motor constant with at least one of a current or voltage of the motor.

In the present invention, the position / speed estimation calculating means estimates and calculates the magnetic pole position or the rotational angular velocity of the rotor which cannot be determined by the 180-degree energization drive and provides the result to the PWM signal generating means. At this time, the magnetic pole position or the rotational angular velocity is estimated and calculated based on the rotational angular velocity command or the torque instruction of the motor and the motor constant. The motor constant is input after the change is compensated by the motor constant compensating means.

The motor constant compensating means compensates for a change in the motor constant due to a rise in temperature due to driving or the like and gives the result to the position / speed estimating calculation means. , And is estimated using at least one of the motor current and voltage. For example, in the first embodiment, PI compensation is performed on the winding resistance so that the error between the motor current command and the motor current becomes zero. Also,
In the second embodiment, compensation is performed with higher accuracy based on the motor voltage equation. In the third embodiment, compensation is performed with reference to the data table.

According to a second aspect of the present invention, the motor constant compensating means switches the compensation mode depending on the state of the motor control system, turns on the compensation mode in a steady state, and compensates for a change in the motor constant. The motor control device according to claim 1, wherein the compensation mode is turned off, the compensation for the change in the motor constant is stopped, and the previous value of the motor constant is used.

In the present invention, the motor constant compensating means comprises:
Compensates for changes in motor constant only in the steady state.

According to a third aspect of the present invention, the motor constant compensating means provides a compensation mode switching grace period before and after the compensation mode switching to prevent the motor constant compensation value from being discontinuous. A motor control device according to claim 2 including mode stabilization switching means.

In the present invention, the motor constant compensating means includes:
In the steady state, the compensation process is always performed. However, if the result compensated by the calculation is significantly different from the previous history value and discontinuous, for example, the previous history value is gradually increased or decreased instead of the mode of the compensation by the calculation. In this case, the mode of compensation is changed, and such a mode is switched to stabilize the operation of the motor.

According to a fourth aspect of the present invention, the motor constant compensating means calculates a true value of the motor constant from at least one of the motor current and the voltage from the voltage equation of the motor. A motor control device according to any one of claims 3 to 3.

In the present invention, the motor constant compensating means comprises:
The true value of the motor constant is calculated based on the motor voltage equation. As a result, estimation with higher accuracy than estimation based on the motor current difference is performed.

According to a fifth aspect of the present invention, there is provided a time measuring means for measuring an elapsed time from the start of operation of the motor, and the motor constant compensating means comprises a motor current and the elapsed time measured by the time measuring means. The motor according to any one of claims 1 to 3, further comprising: a data table that outputs a true value of the motor constant by inputting the data table and compensating for a change in the motor constant with reference to the data table. Control device.

In the present invention, the motor constant compensating means comprises:
The true value of the motor constant is obtained by referring to the data table with the motor current and the elapsed time of the operation. As a result, arithmetic processing by a microcomputer or the like is significantly reduced, which contributes to speeding up, and avoids an estimation error caused by the arithmetic operation.

According to a sixth aspect of the present invention, the steady state determination means is configured to determine at least one of a motor current detection value obtained from the motor current detection means or an estimated rotation angular velocity derived by the position / speed estimation calculation means. A motor control device according to any one of claims 1 to 3, wherein it is determined whether a steady state has been reached.

In the present invention, the steady state determination means determines whether or not the vehicle is in the steady state by calculation from the constantly detected motor current and the estimated rotational angular velocity. This eliminates the need to add a new component for determining the steady state.

Hereinafter, embodiments of the present invention will be described.

[0035]

(Embodiment 1) Hereinafter, Embodiment 1 of a motor control device according to the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of this embodiment. The same components as those of the conventional example shown in FIG. 7 are denoted by the same reference numerals. In FIG. 1, the main circuit is configured by connecting a DC power supply 1 and three sets of two switching elements connected in series in parallel, and an inverter 2 that converts DC power into AC power, and an inverter 2 that converts the DC power into AC power. The motor 3 is driven by the supplied AC power.

On the other hand, in the control circuit, the motor current detected by the current detector 4 and the current detector 5 composed of 4a, 4b, 4c attached to the main circuit, or the motor detected by the output voltage detector 11 At least one of the voltages and the motor speed command ω * or the torque command τ * are input, and the estimated rotational angular velocity of the motor (outside 1) or the estimated magnetic pole position of the rotor is input.

[Outside 2] And a position / velocity estimating calculation unit 12 that computes
And a PWM signal generation circuit 7 for outputting a gate signal to the switching element of the inverter 2.

The motor constant compensating means 13 compensates for a change in the motor constant due to a temperature rise or the like during operation by using at least one of the motor current and the motor voltage in accordance with the output signal of the steady state judging means 14. Then, the magnetic pole position is estimated or the rotational angular velocity is estimated using the compensated motor constant.

Hereinafter, the compensation of the motor constant will be specifically described. In FIG. 1, when the case where only the current detection circuit 5 is used without using the output voltage detection circuit 11 is considered, generally, the motor current command value i * is calculated by using a speed command ω * and an estimated angular velocity (1). It is expressed as 1).

(Equation 1) Here, P is a differential operator, and KP1 and KI1 are a proportional gain and an integral gain, respectively.

Also, the motor winding resistance compensation value

[Outside 3] Is expressed as Expression (2) using a nominal value (nominal value) R0 of the winding resistance of the motor, a motor current command value i *, and a motor current i.

(Equation 2) Here, KP2 and KI2 are a proportional gain and an integral gain, respectively.

Here, if there is an error between the actual winding resistance R of the motor and the compensation value (3) in the steady state, the current difference (i) is obtained by using the compensation value (3) in the position / speed estimation calculation. An error occurs in * -i). Therefore, the applied voltage applied to the motor is changed so that the current difference becomes zero, and PI compensation is performed as in equation (2), whereby the actual winding resistance R of the motor and the compensation value (outer 3) are compared. The error can be made zero.

In the above example, the output voltage detection circuit 11
Is considered, but the present invention can be applied to a case where only the output voltage detection circuit 11 is used or a case where both the output voltage detection circuit 11 and the current detection circuit 5 are used.

Further, in addition to the winding resistance R of the motor,
The present invention can be applied to other motor constants such as inductance and induced voltage constant.

FIG. 2 is a flowchart showing the operation of switching the compensation mode according to the present embodiment. In a steady state, the compensation mode is on, and the motor constant is updated by compensating for a change in the motor constant. In a transient state, the compensation mode is off, and compensation for a change in the motor constant is stopped, and the previous value of the motor constant is used.

FIG. 3 is a characteristic diagram showing switching from a transient state to a steady state in one embodiment of the compensation mode stable switching means. In mode 1, which is a transient state, the compensation mode is off, and the motor constant is a constant value using a previous history value. After the mode 2 which is a steady state, the compensation mode is turned on, and the compensation calculation of the motor constant is started. However, as shown in FIG. 3, when the previous history value does not always match the calculated value, the previous history value is gradually increased or decreased as in mode 2, and the calculated value is used when the calculated value matches the calculated value. Switch to 3.

The same effect can be obtained by providing a hysteresis loop or performing PI compensation so that the error between the previous history value and the calculated value is zero.

As described above, according to the present embodiment, it is possible to compensate in real time for changes in the motor constant due to a temperature rise due to operation, and to realize a stable motor drive system by improving the estimation accuracy. High accuracy speed
Torque control is possible.

Further, by switching the compensation mode, the stability of the motor drive system in a transient state can be ensured, and a stable motor drive system can be realized in any situation.

Further, the compensation mode stability switching means can ensure control stability and reduce noise and vibration associated with the compensation mode switching, realize a more stable motor drive system, and achieve a more accurate speed / torque. Control is possible.

(Embodiment 2) Hereinafter, Embodiment 2 of the motor control device of the present invention will be described.

The motor control device of this embodiment compensates for the motor constant based on the voltage equation of the motor, and performs the motor constant compensation with higher accuracy than the motor constant compensation based on the current difference of the first embodiment. be able to.

Here, as an example, a permanent magnet field type D
A description will be given of a case where the C brushless motor is driven by a current feedback type magnetic pole position estimation to perform sine wave driving during 180-degree energization without a non-energized section.

FIG. 4 is a schematic diagram showing the definition of coordinate axes in magnetic pole position estimation. In general, when sine wave driving is performed, various amounts of the motor are changed from three phases of u, v, and w to two phases of dq axis, as shown in FIG. To convert to DC. The method for converting the three-phase to the two-phase is publicly known and will not be described.

In FIG. 4, θ is the actual magnetic pole position of the rotor, and (2) is the estimated magnetic pole position. Also, △ θ
Is a position error, and has a relationship of Δθ = (outer 2) −θ.

Here, the winding resistance R of the motor is represented by the d-axis inductance and the q-axis inductance by Ld and L, respectively.
Assuming that q and the induced voltage constant are KE, the voltage equation on the dq axis is expressed as in equation (3).

[Equation 3] Here, P is a differential operator, and ω is the rotational angular velocity of the motor.

Here, in the vicinity of the operating point, the dq axis and d '
It is considered that the −q ′ axes are almost coincident, and when approximation of △ θ = 0 is performed, Expression (3) is expressed as Expression (4).

(Equation 4) Here, (1) is the estimated angular velocity.

Here, since the compensation of the motor constant is performed in a steady state, assuming that the differential term in equation (4) is zero, equation (5)
Can be transformed as follows.

(Equation 5) Here, (3) is a winding resistance compensation value of the motor.

From the equation (5), the relationship between the compensation value (outer 3) and the true value of the winding resistance R is obtained regardless of the sign of id '.
The right side is positive when (outside 3) is greater than R, and negative when the opposite is true. Therefore, compensation of the winding resistance is performed as in equation (6).

(Equation 6) Here, equation (6) uses a discrete time system for performing calculations by a microcomputer or the like, where nTs is the current sampling time and (n-1) Ts is the immediately preceding sampling time. KR is an integral gain.

In the equation (6), only the integration on the right side of the equation (5) is performed. However, by adding a proportional term and performing PI compensation, the response is further improved.

Further, when the sign of id 'does not change, equation (6) can be divided by id' to reduce the operation time.

As described above, according to the present embodiment, the first embodiment
The motor constant compensation can be performed with higher accuracy than the motor constant compensation based on the current difference described above, and more accurate speed / torque control can be realized.

In the above description, the sine wave drive of the DC brushless motor for estimating the magnetic pole position has been described as an example. However, the present invention can be applied to other motors and drive systems.

Further, the present invention can be applied not only to the winding resistance of the motor but also to other motor constants such as inductance and induced voltage constant.

(Embodiment 3) Hereinafter, a third embodiment of the motor control device of the present invention will be described. FIG. 5 is a block diagram illustrating the configuration of the present embodiment. The same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted because they are duplicated, and only different portions will be described here.

In FIG. 5, a time measuring means 15 for measuring an elapsed time from the start of operation of the motor is provided. A motor constant compensating means 13 inputs the motor current and the elapsed time measured by the time measuring means 15 and And a data table for outputting the true value of the motor constant.

In the above data table, motor constants obtained in advance through experiments and the like are described.
It is possible to always output the true value of the motor constant based on the correspondence map between the elapsed time and the motor current and the motor constant.

Here, the time measuring means 15 can obtain the elapsed time from the start of operation by performing addition from the start of the motor by a microcomputer or the like. However, when addition is performed by a microcomputer or the like, it is necessary to take measures against errors such as overflow.

As described above, according to the present embodiment, it is possible to greatly reduce the operation time required for the motor constant compensation, as compared with the methods of the first and second embodiments in which the motor constant compensation is performed by calculation. is there.

The present invention is applied not only when the current detection circuit 5 is used but also when only the output voltage detection circuit 11 is used or when both the output voltage detection circuit 11 and the current detection circuit 5 are used. It is possible to do.

(Embodiment 4) A motor control device according to a fourth embodiment of the present invention will be described below with reference to the drawings.

FIG. 6 is a block diagram showing the configuration of this embodiment. The same components as those in FIGS. 1 and 5 are denoted by the same reference numerals, and the description thereof will not be repeated because they are the same. Here, only different portions will be described.

In FIG. 6, the steady state determination means 14
A steady state determination is made based on the convergence determination of the motor current detection value obtained from the current detection circuit 5. Specifically, the convergence of the detected motor current value is determined by the following method.

Assuming that the current sampling time is nTs, and the immediately preceding sampling time is (n-1) Ts, the convergence judgment of the detected motor current value is expressed by equation (7).

(Equation 7) Here, ε is a convergence value, and it is considered that a steady state is reached when the difference between the current value of the motor current detection value and the previous history value is equal to or less than ε.

Further, by taking the difference between the current value and the average value of the past previous values, instead of the difference between the current value and the immediately preceding previous value, it is possible to improve the accuracy of the convergence determination. .

Furthermore, the same effect can be obtained by using a motor current detection value passed through an integrating circuit or LPF between the current detectors 4a, 4b, 4c and the current detection circuit 5.

As described above, according to this embodiment, calculations can be performed by a microcomputer or the like without adding new hardware, and a steady state determination can be realized in the same calculation time.

It should be noted that the steady state can be similarly determined by using the estimated rotational angular velocity output from the position / velocity estimating calculation unit 12.

[0078]

According to the first aspect of the present invention, there is provided an inverter for converting DC power into AC power and outputting the same, a PWM signal generating means for controlling an output of the inverter by a PWM signal, and driving by an output of the inverter. And at least one of motor current detecting means for detecting the current of the motor or motor voltage detecting means for detecting the voltage of the motor, and a speed command or a torque command to the motor, and Position / speed estimating means for estimating the magnetic pole position or rotational angular velocity of the rotor based on the output and outputting to the PWM signal generating means; and motor constant for compensating for the change of the motor constant and outputting to the position / speed estimating means. Compensating means; and steady state determining means for determining whether the control system of the motor has reached a steady state. The constant compensating means may be a motor control device configured to compensate for a change in the motor constant using at least one of a current and a voltage of the motor according to an output signal of the steady state determining means. In addition, it is possible to compensate in real time for changes in motor constants due to temperature rise due to operation, and to improve the estimation accuracy, realize a stable motor drive system, and achieve high-precision speed / torque control. It has the effect of saying.

According to the second aspect of the present invention, the compensation mode is switched according to the state of the motor control system. In the steady state, the compensation mode is on and the change in the motor constant is compensated. In the transient state, the compensation mode is off. With the motor control device that stops compensation for changes in the motor constant and uses the previous value of the motor constant, the stability of the motor drive system in the transient state can be ensured, and it is stable in all situations This realizes an effect that a more accurate speed / torque control is possible.

According to a third aspect of the present invention, a motor control device including a compensation mode stabilization switching means for smoothly switching a compensation mode ensures control stability accompanying the compensation mode switching. Noise and vibration can be reduced, a more stable motor drive system can be realized, and more accurate speed / torque control can be achieved.

According to a fourth aspect of the present invention, there is provided a motor control device wherein the motor constant compensating means calculates a true value of the motor constant from at least one of the motor current and the motor voltage from a voltage equation of the motor. As a result, it is possible to perform calculations using a microcomputer without adding new hardware, and it is possible to directly compensate for motor constants without estimating the temperature, and to maintain the same cost. There is an effect that high accuracy can be achieved because there is no interference with the influence of variations due to component tolerances.

According to a fifth aspect of the present invention, there is provided a time measuring means for measuring an elapsed time from the start of operation of the motor, wherein the motor constant compensating means comprises a motor current and the elapsed time measured by the time measuring means. The motor according to any one of claims 1 to 3, further comprising: a data table that outputs a true value of the motor constant by inputting the data table and compensating for a change in the motor constant with reference to the data table. By using a control device, it is possible to greatly reduce the calculation time required for motor constant compensation, achieve more accurate motor constant compensation, and further reduce the calculation error because the motor constant compensation calculation is unnecessary. This has the effect that it can be greatly reduced.

According to a sixth aspect of the present invention, the steady state determining means is configured to determine at least one of a motor current detection value obtained from the motor current detecting means or an estimated rotational angular velocity derived from the position / speed estimation calculating means. By using a motor control device that determines whether or not a steady state has been reached, it is possible to perform calculations using a microcomputer without adding new hardware, and it is possible to perform calculations at the same cost and calculation time. There is an effect that the state can be determined.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a motor control device of the present invention.

FIG. 2 is a flowchart showing a compensation mode switching operation in the embodiment.

FIG. 3 is a characteristic diagram showing an operation of a compensation mode stable switching unit in the embodiment.

FIG. 4 is a vector diagram showing the definition of coordinate axes in magnetic pole position estimation.

FIG. 5 is a block diagram showing the configuration of another embodiment of the motor control device of the present invention.

FIG. 6 is a block diagram showing the configuration of another embodiment of the motor control device of the present invention.

FIG. 7 is a block diagram showing a configuration of a conventional motor control device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 DC power supply 2 inverter 3 motor 4, 4 a to 4 c current detector (motor current detection means) 5 current detection circuit (motor current detection means) 6 vector control operation means 7 PWM signal generation circuit (PWM signal generation means) 8 temperature estimation Means 9 Thermal constant output means 10 Resistance value estimation means 11 Output voltage detection circuit (motor voltage detection means) 12 Position / speed estimation calculation unit (Position / speed estimation calculation means) 13 Motor constant compensation means 14 Steady state determination means 15 Time measurement means

Claims (6)

[Claims] 1. An inverter that converts DC power into AC power and outputs the same, a PWM signal generating unit that controls an output of the inverter by a PWM signal, and a motor that detects a current of a motor driven by an output of the inverter. At least one of current detection means and motor voltage detection means for detecting the voltage of the motor, and a speed command or a torque command to the motor are input, and a magnetic pole position or a rotational angular velocity of a rotor is determined based on a motor constant of the motor. Position / speed estimating means for estimating and outputting to the PWM signal generating means, motor constant compensating means for compensating for a change in the motor constant and outputting to the position / speed estimating means, and a control system for the motor And a steady state determining means for determining whether the motor has reached a steady state. According to the output signal of the state determination means,
A motor control device configured to compensate for a change in the motor constant using at least one of a current and a voltage of the motor. 2. A motor constant compensating means switches a compensation mode according to a state of a motor control system, and in a steady state, turns on a compensation mode to compensate for a change in a motor constant.
2. The motor control device according to claim 1, wherein in a transient state, the compensation mode is turned off to stop compensation for a change in the motor constant, and the previous value of the motor constant is used. 3. The motor constant compensating means includes a compensation mode stabilizing switching means for providing a compensation mode switching grace period before and after the compensation mode switching to prevent the motor constant compensation value from becoming discontinuous. The motor control device according to claim 2. 4. The motor constant compensating means calculates a true value of a motor constant from at least one of a motor current and a voltage from a voltage equation of the motor. A motor control device according to claim 1. 5. A motor measuring apparatus comprising: a time measuring means for measuring an elapsed time from a start of operation of the motor; a motor constant compensating means for inputting a current of the motor and an elapsed time measured by the time measuring means, and 4. A data table for outputting a true value of a motor constant, wherein a change in motor constant is compensated by referring to the data table.
The motor control device according to claim 1. 6. The steady state determining means determines whether a steady state has been reached based on at least one of a motor current detection value obtained from the motor current detecting means or an estimated rotational angular velocity derived by the position / speed estimation calculating means. The motor control device according to any one of claims 1 to 3, wherein it is determined whether or not the motor control is performed.