JPS6337598B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a speed control device for a DC motor. In general, this type of control device is controlled so that the actual speed value (detected value) follows changes in the set speed as quickly as possible and matches the set value, and the actual speed value (detected value) is controlled so that it matches the set value by following changes in the set speed as quickly as possible. It is desirable that the value does not fluctuate.

[Conventional technology]

Conventionally, as this type of control device, a speed control system having an armature current control loop (ACR loop) as a minor loop is known. However, such systems generally do not have many measures against load torque fluctuations, and therefore, for example, when the load torque suddenly changes, the motor speed temporarily fluctuates and recovers after a predetermined time. It is difficult to suppress fluctuations within a certain value, and there is a certain limit, which has the disadvantage that optimal control cannot be performed. This is because correction of speed fluctuations when the load suddenly changes is performed exclusively by the speed regulator, but the correction speed depends on the control parameters of the speed regulator. Therefore,
The present applicant simulates load torque from speed and current, and adds the simulated current value to the speed regulator output to perform so-called advance compensation for disturbances, thereby reducing speed due to load torque fluctuations. We proposed a method to inhibit and control fluctuations.

FIG. 1 is a block diagram showing the configuration of such a control device. In the figure, 1 is a speed regulator (ASR), 2 is a current regulator (ACR), 3 is a firing angle regulator, 4 is a thyristor converter, 5 is a DC motor,
6 is a speed generator, D is a current detector, and 7 is a state observation device consisting of field simulating elements 71, 72, proportional elements 73, 74, integral elements 75, 76, and the like. Note that S in the figure is a Laplace operator, and T _M is a starting time constant of the electric motor.

The speed regulator 1 provides an adjustment output as a current command value i ^* to the current regulator 2 so that the actual speed value n detected by the speed generator 6 becomes the target value n ^* . The current regulator 2 adjusts and calculates the current detected value i from the current detector D to be equal to the current command value i ^* , and controls the phase of the thyristor converter 4 via the ignition pulse generator 3. Thus, the DC motor 5 is controlled to a desired speed. In the state observation device 7, the field quantity and the electric motor are simulated by elements 71 and 75, and from the output thereof, the electric motor generated torque τ _M and the estimated speed value n^ (in addition, "∧"
Marks represent estimated values. ) is obtained. in this case,
The motor generated torque τ _M is obtained by multiplying the detected current value i by a gain φ corresponding to the field magnetic flux, and is obtained as τ _M =iφ. The estimated speed value n is subtracted from the actual speed value n at the summing point _P0 to obtain a quantity n-n, which is applied to the integral element 76 via the proportional element 74, whereby the load torque τ _L is Estimated calculation is performed. This load torque estimated value τ^ _L is given to the field simulation element 72, where the amount τ^ _L /φ, that is, the current value i^ ₁ equivalent to the load torque is estimated and calculated. Since this estimated calculated value i ₁ is added to the output of the speed regulator 1, a current i ₁ corresponding to the load torque τ _L flows prior to the correction command of the speed regulator 1, and thereby the load torque τ _L Fluctuations caused by this are suppressed. In other words, in a speed control loop that has a current control loop as a minor loop, a state observation device is provided that estimates and calculates a current i^ ₁ equivalent to the load torque from each actual value of speed and current, and the current estimated value i ₁ is used to adjust the speed. This is to suppress speed fluctuations due to load torque fluctuations by adding this to the motor output and controlling it. In this case, the output of the current regulator 2 can be used as the actual current value.

[Problem that the invention seeks to solve]

However, in such a method, if there is a ripple in the output of a detector that extracts the actual speed value, such as a speed generator, this ripple is amplified in the condition observation device, so estimation is performed to increase the effect of suppressing speed fluctuations. If the torque response is accelerated, the ripple increases significantly, and the current transmission also changes in accordance with this ripple. For this reason, if the ripples included in the current detection value cannot be ignored, there is a problem in that even the control method using the above-mentioned state observation device cannot achieve the desired improvement effect.

This invention was made in view of these points,
An object of the present invention is to provide a control device capable of suppressing speed fluctuations in response to load torque fluctuations by eliminating the influence of ripples included in speed detection values in a motor load torque compensation control method using a state observation device as described above. do.

[Means for solving problems]

For a speed control device for a motor having a current regulation loop as a minor loop within the speed regulation loop, a first integral element for estimating the motor speed and a velocity estimated value and a velocity ripple estimated value are calculated from a detected velocity value including velocity ripple. first and second coefficient elements that multiply the reduced deviation by a predetermined coefficient, and a second integral element that adds and integrates the output of the first coefficient element to the product obtained by multiplying the speed target value and the estimated ripple value. a third integral element that estimates a speed ripple by adding and integrating the output of the second integral element multiplied by the speed target value and the output of the second coefficient element; a load torque estimating element that estimates the load torque by multiplying it by a coefficient and then integrating it; a calculation element that calculates the motor generated torque from the detected current value; and a predetermined difference between the output of the calculation element, the output of the load torque estimation element, and the deviation. an addition/subtraction element that adds and subtracts the multiplied coefficient and supplies the result to the first integral element;
a conversion element that converts the output of the load torque estimation element into a current amount; and an addition element that adds the output of the conversion element, a current target value (output of the speed adjustment loop), and a detected value to the current adjustment loop. , will be established.

[Effect]

Estimating the load disturbance torque from the actual values (detected values) of the motor's current and speed, converting the estimated torque into a current amount, and estimating the ripple included in the detected speed value when performing load disturbance compensation control. death,
A speed estimation value and a load torque estimation value that do not include this are obtained.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of the invention. As is clear from the figure, the speed generator 6
A ripple observer 8 is provided to estimate and calculate the ripple γ present in the output of
The feature is that this n^ is used as the actual value signal for speed control. Note that other points are exactly the same as those in FIG. 1, so explanations will be omitted.

The ripple observer 8 includes two multipliers 83 and 84.
and two integrators 85 and 86 are connected in cascade, and the oscillation frequency can be controlled by voltage, which is a so-called voltage controlled oscillator (VCO).
A speed setting value n ^* is given to one input of each of the multipliers 83 and 84 in order to simulate that the output ripple frequency of the speed generator 6 changes in proportion to the speed. In addition, the inputs of the integrators 85 and 86 contain the deviation e between the actual speed value n obtained from the output of the addition point _P0 in the state observation device 7 and the estimated value n^, which is actually (n-n^) + (γ−γ^) with gains g ₃ , g ₄
By adding the amplified amounts respectively, the ripple amplitude and frequency are controlled and the estimated ripple value γ^ is made to match its actual value γ. Therefore, if the ripple γ is correctly estimated by the ripple observer 8, the estimated speed value n^ will be a signal that does not include ripples, and the estimated torque signal will also not include ripples, so This enables stable current control that is not affected by ripple.

〔Effect of the invention〕

As described above, according to the present invention, when performing load disturbance torque compensation control of a DC motor using a state observation device, the ripple disturbance included in the detected speed value is estimated by the ripple observation device, and the estimated value γ The speed detection circuit is simulated by adding ^ to the speed estimate n^ estimated by the state observation device, and the above speed estimate n^ is used as the actual speed value instead of the speed detector (speed generator) output signal. By using this, it is possible to suppress speed fluctuations due to load torque fluctuations without affecting the current control loop due to speed ripples.

This invention is applicable not only to speed control of a DC motor as described above, but also to control by removing ripples when disturbance ripples exist, and to measurement of true values excluding ripples. can do.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a conventional speed control device, and FIG. 2 is a block diagram showing an embodiment of the present invention. Description of symbols, 1... Speed regulator, 2... Current regulator, 3... Firing angle regulator, 4... Thyristor converter, 5... DC motor, 6... Speed generator, 7...
...State observation device, 8...Ripple observation device, 71,7
2... Field simulation element, 73, 74, 81, 82...
...Proportional element, 75, 76, 85, 86... Integral element, 83, 84... Multiplier, D... Current detector.

Claims (1)

[Claims] 1. An armature current or a motor current component equivalent to this is set as a current command value in a speed adjustment loop that adjusts the speed so that the detected speed value of the motor matches its target value. A speed control device for an electric motor having a current regulation loop that adjusts a first integral element for estimating the motor speed; and a deviation obtained by subtracting the estimated speed value and the estimated speed ripple value from the detected speed value including the speed ripple. first and second coefficient elements that multiply by a predetermined coefficient, and a second coefficient element that adds and integrates the output of the first coefficient element to the product obtained by multiplying the target speed value and the estimated ripple value.
a third integral element that estimates a speed ripple by adding and integrating the output of the second integral element multiplied by the speed target value and the output of the second coefficient element; a load torque estimating element that estimates load torque by integrating the deviation after multiplying it by a predetermined coefficient; a calculation element that calculates the motor generated torque from the detected current value; an output of the calculation element, an output of the load torque estimation element, and the an addition/subtraction element that adds or subtracts the deviation multiplied by a predetermined coefficient and provides the result to the first integral element; a conversion element that converts the output of the load torque estimation element into an amount of current; and a conversion element that converts the output of the conversion element and the current target value ( A speed control device for an electric motor, comprising: an addition element that adds the output of the speed control loop) and the detected value and provides the result to the current control loop.