SU811468A1 - Device for adaptive control of dc electric motor - Google Patents

Description

A drawing is a block diagram of the device.

The device comprises an adder 1, a controller 2, a limiting unit 3, a switching element 4, a filter 5 and a comparator 6.

The input of the adder 1 receives two compared signal: the task on the motor current and the value proportional to the motor current. The output of the adder 1 is connected to the input of the regulator 2 by two channels: one directly, the other through the limiter 3 and the switching element 4. The first channel is turned on permanently, and the second, passing through the limiting unit 3 and the switching element; when the motor current is less than the response threshold, and turns off when the current is greater than this threshold. In this case, when the second channel is turned on, the transfer function of the controller becomes integral with a small constant time, and when the second channel is disconnected, it becomes the norm-integral. In addition, a signal proportional to the motor current is fed through the active narrowband filter 5 to the input of the comparator 6, where it is compared with a predetermined trigger threshold. The output of the comparator 6 is connected to the control input of the switching element 4 and controls its switching.

The device works as follows. In the initial state, when the engine is idling with a small core current, a signal proportional to the current of the double filter through filter 5, which filters the current ripple frequency associated with the asymmetry of the control pulses of the static converter, enters the comparator 6, where it is compared with threshold. Current pulses do not exceed the trigger threshold of comparator 6, and at its output there is a constant signal of the polarity that includes switching element 4. The second control channel is turned on, and the transfer function of the controller is integral with a small time constant. The motor current corresponds exactly to the reference, therefore the output voltage and S of adder 1 is zero.

As the motor current jumps, Uz increases. If the reference jump is small, i.e., within a continuous current zone, all f / v passes through the limiter in the second control channel, and the signal integration speed of regulator 2 will be proportional to the voltage — If the current reference jump of the motor is large and exceeds the discontinuous zone current, the voltage bg passes in the second control channel with amplitude limitation, and the integration rate of the signal U- does not exceed a certain value in such a way that the voltage increase during the pulsation period of the current does not take it beyond boundary value of intermittent current.

The presence in the proposed device of the limiting power amplifier allows

to exclude overshoot in the motor current with its rapid growth from the discontinuous current zone to any value of the continuous current mode.

Claims (2)

Invention Formula 25 A device for adaptive control of a DC motor containing a regulator, at a feedback rate which includes a chain of capacitor and resistor, shunted by the executive circuit of the switching element, the control circuit of which is connected to the comparator, whose inputs are connected to A setting device and a current sensor, characterized in that, in order to eliminate the overshoot, an adder and a limiting unit are inputted to it, the output of the first of which is connected to one of the controller inputs directly, and to the other through a limiting unit and a second switching circuit actuator. Information sources taken into account during the examination 1. Patent of Sweden 363550, cl. H 02 R 13/32, 1973. 2. V. Garnov, et al., Unified Systems of Electronic Control of Electrically Driven Metallurgy, Moscow, Metallurgists, 1977, pp. 113-114 (prototype).