JPH0515193A - Gain regulating method for inverter unit - Google Patents

Abstract

PURPOSE:To make it possible for any one to set a same gain by automatically calculating the gains of P, I, D for providing a predetermined response based on an inertial moment calculated from an integrated value and a detected value. CONSTITUTION:Maximum allowable rotation and rotary amount are set for a motor movable range input 1. A first motor operating pattern is then calculated based on the motor movable range and a motor is operated according to thus determined pattern. Positive and negative maximum current command values-are detected, at that time, in the region of current command value. Thus detected positive and negative maximum currents are then employed in operating pattern again according to an algorithm, followed by calculation of an inertial moment. Current is then accumulated and a maximum angular speed is detected in order to calculate a load inertial moment which is employed in the calculation of response having no overshoot. Thereafter, gains of final P, I, D are calculated and regulated.

Description

Detailed Description of the Invention

 [Object of the Invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gain adjusting method for an inverter device which controls a motor at a variable speed by proportional-integral-derivative control (hereinafter referred to as PID control).

[0002]

2. Description of the Related Art As shown in FIG. 10, a conventional gain adjusting method for PID control in an inverter device gives a stepwise speed command to the inverter device, measures the response,
Human beings are proportional (hereinafter P), integral (hereinafter I),
The differential (hereinafter referred to as D) gain was adjusted by experience.

[0003]

However, in the conventional gain adjusting method of the inverter device, it is difficult for an amateur to adjust the gains of P, I, and D because humans adjust the gains by experience. In addition, there are variations in adjustment and length of adjustment time depending on the person making the adjustment.

In view of the above problems, the present invention estimates the load moment of inertia and automatically calculates each gain of P, I and D so as to have a predetermined response, so that everyone has the same gain. An object of the present invention is to provide a gain adjusting method of an inverter device that can be set. [Constitution of Invention]

[0005]

In order to achieve the above object, the present invention calculates, in an inverter device for variable speed control of a motor, an operation pattern for estimating the moment of inertia from the movable range of the motor, Detects the current value when operating in a pattern or the maximum value of the current command value,
The operating range is calculated again from the movable range, the current value or the current command value, and the current or the current command during operation in this recalculated operation pattern is integrated, and the maximum angular velocity is further detected, the integrated value, the detected value. Calculate the moment of inertia from
Based on the calculated moment of inertia, proportional to speed control,
Integral and derivative gains are calculated so that the speed control system is in the form of a Bessel low-pass filter, and a predetermined response is obtained. provide.

[0006]

According to the present invention thus constructed, the moment of inertia is estimated and calculated according to the principle shown in FIG. Figure 8
When is expressed by an equation, the following equation (1) is obtained. In FIG. 9, when the motor is operated so that the motor angular velocity becomes the angular velocity ω, the current command becomes I _{q in} FIG. 9.

However, I _q is a disturbance torque component I such as friction.
_{Since L} is included, it is necessary to exclude this I _L when calculating the moment of inertia. Where I _L = f
Assuming (ω), the following expression (2) is established. Therefore, the moment of inertia is calculated by the following equation (3) excluding the influence of the disturbance torque I _L. The gain calculation is performed so that the block of the speed control system shown in FIG. 6 matches P, I, and D of the transfer function of the second-order Bessel filter.
Determine the gain. The second-order Bessel filter is expressed by the following equation (4)
, The response can be defined by ωN.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a general flowchart of this embodiment. In the motor movable range input 1, the maximum allowable rotation and the motor rotation amount are set. Next, the first motor operation pattern is calculated based on the motor movable range (2 in the figure).
This processing 2 will be described in detail with reference to FIG. In FIG. 2, the maximum allowable rotation is set to ω _a and the motor movable range is set to θ _a0 .

The operation amount is calculated in advance from the preset time T (FIG. 3) and the set value ω _a (20 in FIG. 2), and it is checked whether this value exceeds the allowable operation range (FIG. 2).
21).

If it exceeds, the set value ω and the time T are calculated from the internally set parameters (2 in FIG. 2).
2), check whether T does not exceed Ti (2 in Fig. 2).
3) If it exceeds, T = Ti.

Next, in 3 of FIG. 1, the motor is operated according to the operation pattern (FIG. 3) determined in 2 above. At this time, the positive and negative maximum values of the current command value used in 4 in FIG. 1 are detected in the area of the current command value (13, 14 in FIG. 6). It detected maximum positive current I _qN, the maximum negative current I _qP
When, 4 of Figure 1, this I _qN, according to the algorithm of FIG. 4 and FIG. 5 using I _qP, recalculates the operation pattern. After the operation pattern is recalculated by 4 in FIG. 1, the moment of inertia is calculated by the process 5 in FIG. The currents in the regions 13 and 14 in FIG. 6 are integrated and the angular velocity at time 12 is detected. This value is substituted into the above equation (3) to calculate the load moment of inertia. The moment of inertia calculated in 5 according to 6 in FIG. 1 is substituted into J in FIG. Then, the transfer function of FIG. 7 becomes the following expression (5).

[0012]

[Equation 1] In order that the above equation (7) agrees with the above equation (4), K _P ,
If K _I and K _A are determined, a response without overshoot is obtained. At this time, the response level is determined by changing the value of ω _{N in} the above equation (4). After that, 1 is executed again to calculate the final P, I, and D gains and adjust each gain (7 in FIG. 1).

[0013]

As described above, according to the present invention, P
The gain of the motor speed control is automatically adjusted by the ID control, so that there is no variation in setting and the setting time is constant.

[Brief description of drawings]

FIG. 1 is an overall flowchart showing an embodiment of the present invention.

FIG. 2 is a flowchart showing a procedure for creating an operation pattern in one embodiment of the present invention.

FIG. 3 is a diagram showing a time T in one embodiment of the present invention.

FIG. 4 is a flowchart showing a procedure for creating an operation pattern in one embodiment of the present invention.

FIG. 5 is a flowchart showing a procedure for creating an operation pattern in one embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between a speed operation pattern and a current command in one embodiment of the present invention.

FIG. 7 is a block diagram showing speed control in one embodiment of the present invention.

FIG. 8 is a model diagram of a motor according to the present invention.

FIG. 9 is a diagram showing a relationship between an angular velocity and a current command according to the present invention.

FIG. 10 is a flowchart showing a gain adjusting method in a conventional inverter device.

[Explanation of symbols]

1 ... Motor movable range input, 2 ... First motor operation pattern calculation, 3 ... Motor operation, 4 ... Positive and negative maximum current detection, 5 ... Inertia moment calculation, 6 ... PID gain calculation, 7 ... Adjustment of each gain

Claims (1)

Claim: What is claimed is: 1. In an inverter device for variable speed control of a motor, an operation pattern for estimating a moment of inertia is calculated from a movable range of the motor, and a current value when operating in the operation pattern, or Detects the maximum current command value,
The operation range is calculated again from the movable range, the current value or the current command value, and the current value during operation or the current command value is integrated by the recalculated operation pattern, and the maximum angular velocity is further detected, and the integrated value and The moment of inertia is calculated from the detected value, and based on the calculated moment of inertia, the proportional, integral, and derivative gains of speed control are calculated so that the speed control system has the shape of a Bessel low-pass filter, and the prescribed response is obtained. A gain adjustment method for an inverter device, characterized in that the gain adjustment is performed so as to obtain a predetermined response.