SU1640806A1 - Valve-type electric drive - Google Patents

Abstract

The invention relates to electrical engineering. The purpose of the invention is to improve the quality of stabilization of the rotational speed and acceleration. The valve actuator contains two comparison nodes 7 and 8, two nonlinear elements 11 and 12, a multiplication unit 14, a relay element 10, a differentiation unit 13, which depend on mode, operation speed control, acceleration and current. 5 il. (L S oe 00 00 O f

Description

The invention relates to electrical engineering, in particular to an automated electric drive with a valve motor.

The aim of the invention is to improve the quality of stabilization of rotational speed and acceleration.

Fig „1 shows the block diagram of the valve electric drive; Figures 2 and 3 show the static characteristics of non-linear elements; in fig. 4 - basic electrical 1 circuit of one nonlinear element; Fig 5 is a circuit diagram of a second non-linear element.

The valve drive contains a synchronous motor 1 (FIG. 1), the rotor of which is made with permanent magnets, and the root winding is connected to the output of the transistor. Inverter 2, the power input of which is connected to the output of the rectifier 3 connected to the AC outlet. the input of the inverter 2 is connected to the multichannel output of the distributor 4 pulses, three inputs of which are connected to the outputs of the sensor 5 of the rotor position mounted on the shaft of the synchronous motor 1, and the fourth input of the distribution Ithel 4 pulses connected to the output of the relay member 6 '

A rotational speed sensor 7 is installed on the shaft of the synchronous electric motor 1, the output of which is connected to the second input of the first comparison unit 8, the first input connected to the output of the rotational frequency setting device (not shown). The drive also contains a block of 9 current sensors included in the output circuit of the inverter 2.

The input of the relay element 6 is connected to the output of the second comparison node 10, provided with first, subtractive, and second and third, summing, inputs. The electric drive is equipped with the first 11 and second 12 nonlinear elements, differentiation units 13 and multiplication 14.

The output of the first comparison unit 8 is connected to the third input of the second comparison unit 10 and the inputs of the second non-linear element 12 and differentiation unit 13. The outputs of the nonlinear element 12 and block 13 differen

0

five

0

five

0

five

0

five

The circuits are connected to the inputs of multiplication unit 14, respectively, the output of which is connected to the first input of the comparison unit 10, the second input of which is connected to the output of the first nonlinear element 11, the input connected to the output of the current sensor unit 9.

The first non-linear element 11, which implements a three-stage static characteristic with a dead zone (Fig. 2), contains two comparators 15 and 16 and an operational amplifier 17. The response threshold of the comparators 15 and 16 is set by voltages taken from the potentiometers installed at the inputs of the comparators. The signal at the output of the operational amplifier 17 is proportional to the difference of the output signals of the comparators 15 and 16. Comparators 15 and 16 can be implemented, for example, on chips.

The second non-linear element 12, implementing the one shown in FIG. 3, the static characteristic comprises three operational amplifiers 18-20 (Fig. 5). Operational amplifier 18 implements the selection circuit of the input signal module. The gain of amplifier 18 is determined by the variable resistance in the feedback circuit. An operational amplifier .19, using anti-parallel zener diodes, implements a limiting circuit. Operational amplifier 20 is an output of output signals of operational amplifiers 18 and 19 and the bias voltage removed from the divider.

i

Valve motor works

in the following way.

With small speed control errors in absolute value, smaller than the specified maximum error om (Fig. 3), the output signal U. of the second nonlinear element 12 does not depend on the input signal proportional to the current error in the speed control and is equal to C. In this case, the switching function relay element 6 has the form

Ј + s,

where o is the derivative of the error, and the relay element 6, operation in the sliding mode, stabilizes the rotation frequency.

In this case, the coefficient C, which has the dimension of time, determines the speed of the closed loop of the rotational speed control.

If the frequency of rotation exceeds the value of y, the output signal U at the nonlinear element 12 is proportional to 16

rational of the module error frequency

. v-f.

Liz

where the error is given

(determined by the specified drive acceleration). The switching function takes the form

Ј - f & 0 (1) 5

Due to the linear dependence of the output signal U of the nonlinear element 12 on the error, the processing of large mismatches occurs with constant acceleration. In this case, the relay element 6, operating in the sliding mode, ensures the acceleration independence from the parameters of the control object.

Nonlinear element 11 provides a cut-off current. When the drive is overloaded and the current i exceeds the value of i (Fig. 2), a signal appears at the output of the nonlinear element 11

and,

U, obviously a larger amount

signals arriving at the summing inputs of the reference element 10. At the output of the relay element 6, a signal appears, leading to a decrease in current, and further, work in a sliding mode, the relay element provides current limiting at the level ",.

Thus, the quality of stabilization of the rotation frequency and acceleration is improved in the presence of parametric disturbances in the object, control (load of the electric drive).

08066

Claims (1)

Invention Formula A valve actuator containing a synchronous motor, the rotor of which is made with permanent magnets, and the root winding is connected to the output of a transistor inverter, the power input of which is connected to the output of a rectifier equipped 0 five 0 five 0 five 0 five 0 the network connection, and the multichannel control input of the inverter is connected to the multichannel output of the pulse distributor, three inputs of which are connected to the outputs of the rotor position sensor mounted on the electric motor shaft, and the fourth input of the pulse distributor is connected to the output of the relay element, the frequency sensor installed on the shaft of the electric motor, the output of which is connected to the second input of the first comparison node, the first input of which is connected to the output of the rotational speed setting device, the second node cf Avneni - with the first, summing, and second, subtractive, inputs, the output of which is connected to the input of the relay element, the block of current sensors included in the output circuits of the inverter is distinguished, and with the fact that, in order to improve the quality of stabilization of the rotation frequency and acceleration, Introduced the first non-linear element with a three-step characteristic, having a non-interconnection zone, and a second non-linear element with the characteristic shown in FIG. 3, the multiplication unit and the differentiation unit, and the second comparison node is provided with a third summing input connected to the output of the first comparison node connected to the inputs of the second nonlinear element and the differentiation unit, the outputs of which are connected to the corresponding inputs of the multiplication unit whose output is connected to the first in the hopping of the second comparison node, the second input of which is connected to the output of the first nonlinear element, the input connected to the output of the current sensor unit. + / 53 FIG. five