SU764080A2 - Device for controlling multimotor drive - Google Patents

Description

(54) DEVICE FOR CONTROLLING MULTI-MOTOR ELECTRIC DRIVE

one

This invention relates to the control of multi-motor electric drives.

According to the main author. St. No. 508886 is a known system for controlling the speeds of electric motors, comprising speed controllers, a speed-selection unit, a rate forming unit for changing the reference speed of the mill speed, speed setting setting nodes, selective elements and a divider, as well as motor speed control systems.

The disadvantage of this device lies in the fact that it is practically difficult to ensure simultaneous starting and stopping of all electric motors of a multi-motor electric drive of a continuous cold rolling mill, which leads to disruption of the technological process, namely, breakage of the rolled strip and excessive overload of the electric motors of the drive.

The purpose of the invention is to improve the accuracy of synchronization of the trogann and stopping of electric motors.

This goal is achieved by the fact that the proposed device is additionally equipped with three groups of schemes I, a scheme

OR, pulse counting units, a maximum path size determining unit, output and inputs connected respectively to the second inputs of the first and second groups of AND circuits connected to the inputs of the speed control units, the first and third outputs of which are connected to the corresponding inputs of the first and second groups of AND circuits , and the second-- through the third group of circuits AND connected to the pulse counting units, the outputs connected to the inputs of the unit

fO determine the maximum value of the path, the first outputs of the speed control units are connected to the inputs of the OR circuit connected to the second, interconnected inputs of the third group of AND circuits, and the third inputs of the first group of AND circuits to the first inputs of the second group of AND circuits respectively sources external commands "acceleration and" stop.

The drawing shows the block diagram of the device ...

20 The device contains a system 1 of the speed control of electric motors, the first circuit AND 2i of the speed control system of the first motor, the second circuit AND 3i of the control system

speed of the first motor, speed control unit 41 of the first electric motor, third AND 5i circuit of the speed control system of the first electric motor, pulse counting unit 6 "of the speed control system of the first electric motor, speed control systems from 2nd to 5th electric motor, OR 8 circuit , block 9 determine the maximum value of the path.

The AND (2, -2,) (3, -3,) (5, -5п) schemes included in the speed control systems (7i-7c) are normal keys that pass information when there are permissions on all inputs and on diodes and resistors.

Speed control units (4i-4.,) Represent each system consisting of an electric motor with current and speed sensors, a power source, current regulators and speeds. Pulse counting units () are common counters, for example, binary ones.

The OR 8 circuit is a collection circuit that passes a signal to the output when it appears on any of the inputs and is made on diodes. The maximum path value determination unit 9 is a device that alternately compares input parallel codes, selects and stores the maximum code value, and consists of input keys of the code comparison device, a static register, and logic elements.

System I of the Skbrs control modes is connected to each of the second inputs of the speed control units (4i- 4c), the first and third inputs of which are connected respectively to the outputs of the first (2i-2) and second (3'-3ts) I.

The inputs of the OR 8 circuit are connected to the first outputs of the speed control units () and the first inputs of the first AND circuits (2 (-2), the third inputs of the latter are connected to the external "overclocking (P)" command, the output of the OR circuit 8 is the ccfeflWffeirCoi Second inputs of the third AND circuits ( ), the first inputs of which are connected to the second outputs of the speed control units (4 I-4p), and the outputs are connected to the inputs of the corresponding pulse counting units (6 | -6), the outputs of the pulse counting units (6f-bp) are connected to the corresponding inputs of the block 9 determine the maximum path size and the second inputs of the second And (3i-3p) circuits, the third inputs of which are connected to the third outputs of the speed control units (4i-4p), and the first inputs - with an external "stop (O)" command. The BTOfJJtf fiStbsaMft first AND outputs (2i- 2 „).

The device works as follows

System I control with CREDIT modes of electric motors provides the issue of the selected speed level

with a given acceleration and ratio of speeds to speed control units (4, -4 "). . During operation of any (i-ro) electric motor of a multi-motor electric drive, its speed control unit 4 supplies a signal to the third input of the AND 3j circuit — the speed is not equal to zero (). which opens the scheme AND 3i.

When the motor is stopped, its speed control unit 4 ;, feeds the OR 8 circuit and the first input of the corresponding circuit AND 2j a signal — the speed is equal to nulca (V 0), which opens the circuit AND 2), and passes through the circuit OR 8, opening schemes AND (51-5).

The device operates in two modes - moving and stopping electric motors.

In the mode of moving the motors of a multi-motor drive, the third inputs of the first circuit AND (2i-2) speed control systems () receive an external command (P) "overclocking" and start to increase with zero signals from the outputs of the system 1 controlling the speed modes of the electric motors, which arrive at second inputs of the speed control units (4i-4c). Due to the different static moments on the electric motors, different dynamics of the electric drives and other reasons, they cannot start moving at the same time.

After moving the aforementioned electric motor, the pulses from its pulse sensor move the speed control unit 4t. pass through the AND 5i circuit (all AND 5i-5p circuits are open if at least one electric motor is stopped, since the V O signals, the passage through the OR 8 circuit, open all third I circuits) to the GI pulse counting unit, which records the distance traveled. In block 9 for determining the maximum value of the path, the value of the maximum value of the path is recorded and from the output it is fed to the second inputs of the AND circuits (2 | -2p). If any electric motor does not move, the signal of the maximum path from block 9 will pass through an AND 2 circuit (it is open with signals V O of this speed control unit and “P) to the speed control unit of engine 4 of speed control system 7, forcing starting this engine.

With the start of movement of the electric motor, the circuit AND 2h closes (since V e 0) and the speed control unit 4 c goes to the operating mode.

In the stop mode of the electric motors, the first inputs of the second circuits AND () of the speed control systems (7i-7g) receive an external command "O" and also start decreasing to zero signals from the outputs of the system I controlling the speed modes of the electric motors. Due to the different static moments on the motors, different dynamics of the drives and other reasons, they cannot stop simultaneously while all the signals at the outputs of the system I control the speed modes of the motors zero. After the first shutdown of any (i-ro) electric motor of a multi-motor electric drive, the signal V O from its speed control unit 4i, passes through the scheme OR 8, opens all AND schemes (5 | -5h) and, if at the same time, some drive electric motor moves, pulses from its pulse sensor the displacement of the speed control unit 4 | will pass to the pulse counting unit 6, which records the distance traveled by this electrode of the heater. This information passes through an AND 3 circuit (it is opened with V o signals of this speed control unit and " O) to speed control unit 4, speed control system 7, thereby forcing the control signal of the motor to stop.

The invention makes it possible to improve the process management in cold rolling mills in the continuous heat treatment lines by increasing the timing accuracy of the starting and stopping of the electric motors.

Claims (1)

The invention The device for controlling a multi-motorized actuator St. No. 508886, characterized in that, in order to increase the accuracy of synchronizing the starting and stopping of electric motors, it is additionally equipped with three groups of AND schemes, OR circuit, pulse counting units, a maximum path size determining unit, outputs and inputs connected respectively to the second inputs of the first and the second groups of circuits And connected to the inputs of the speed control units, the first and third outputs of which are connected to the corresponding inputs of the first and second groups of circuits And, and the second through the third group of circuits And connected to pulse counting units, outputs connected to the inputs of the block determining the maximum path size, the first outputs of the speed control units connected to the inputs of the OR circuit connected to the second, interconnected inputs of the third group of circuits And, and the third inputs of the first group of circuits And and the first the inputs of the second group of circuits AND are connected respectively to the sources of the external command “overclocking and “OSTYNOV”