SU1495891A2 - Device for automatic repeated activation of induction motor - Google Patents

Abstract

The invention relates to electrical engineering, in particular to the automation of re-switching of induction motors, and can be used, in particular, in automated installations of submersible electric pumps. The purpose of the invention is to increase the reliability of self-starting by automatically changing the interval before the electric motor is switched on again, determined by the time of complete attenuation of the residual E.D.S. The switching device 1 of the electric motor 10 is controlled by the starting unit 3 via the output signals of the RS flip-flop 16, the switching unit 6 and the fault-storing unit 7. At the same time, the voltage level of the power source 12 (the signal at the R-input of the trigger), the residual eD are taken into account. . With electric motor 10 (signal at the S-input of the trigger) and the presence of an overload of the electric motor (signal at the output of the protection unit). If the voltage of source 12 disappears, the switching device 1 is turned off. Automatic restart (AR) After restoring voltage under the condition of complete attenuation of the residual e.d. motor 10. When the motor overloads under conditions of normal supply voltage, the starting unit 3 switches off the switching device 1, and the overload signal is memorized and the AR is disabled. When overloaded in conditions of high or low supply voltage, the starting unit 3 also turns off the switching device 1, however, the storage of the overload mode does not occur even after the restoration of the supply voltage and subject to complete attenuation of the residual EMF, the automatic reclosing is performed. 1 il.

Description

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12 power supply (signal at the R input of the trigger), residual emf level of the electric motor 10, (signal at the B input of the trigger) and the presence of an overload of the electric motor (signal at the output of the protection unit). When the voltage of the source 12 disappears, the switching device 1 is turned off. Automatic reclosing (AR) is carried out after voltage recovery under the condition of complete attenuation of the residual EMF of the electric motor 10. When the electric motor is overloaded under conditions of normal voltage - 5

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The power supply starting block 3 shuts down the switching device 1, and the overload signal is memorized and the automatic reclosure is disabled. When overloaded in conditions of high or low supply voltage, the starting unit 3 also turns off the switching device 1, however, the storage of the overload mode does not occur even after the restoration of the supply voltage and subject to complete attenuation of the residual EMF, the automatic reclosing is performed. 1 il.

The invention relates to electrical engineering, in particular, to automation of the re-activation of asynchronous motors, and can be used, in particular, in automated installations of submersible electric pumps.

The purpose of the invention is to increase the reliability of self-starting by automatically changing the time interval before the electric motor is turned on again.

: gate, determined by the time of complete attenuation of the residual EMF.

 The drawing shows the block diagram of the device for automatic

: reclosing the asynchronous motor.

The device contains a switching device 1, a protection unit 2, a starting unit 3, a converter 4 of continuous value into a discrete one with an adjustable actuation zone, the first C is a direct sequence voltage filter 5, a switching unit 6, an alarm memorization unit 7, current transformers 8 and 9, asynchronous electric motor 10 mechanically connected to actuator 11, electrically through switching device 1 and current transformers 8 and 9 to power source 12, second filter 13 direct sequence logic inverter s 14 and 15 and RS trigger 16.

The power supply 12 through the first filter 5 is the voltage of the direct sequence connected to the input of the converter 4 connected to the I - input of the RS flip-flop 16 via a logic input. Vertor 15, S-input RS-flip-flop 16 St.

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via a logical inverter 14 with the output of the second filter 13 of the direct sequence, the input of which is connected to the mains between the switching device 1 and the electric motor 10. The short-circuit output is connected to the first inputs of the switching unit b and the starting unit 3. The second input of the hycKOBoro unit 3 connected to one of the outputs of the switching unit 6. The third input of the starting unit 3 is connected to the second output of the switching unit 6 through the accident storage unit 7. The second input of the 6-switching unit is connected to the output of the protection unit 2. The inputs of the protection unit are electrically connected to the secondary windings of the current transformers 8 and 9.

The device works as follows.

At a normal voltage level (Power supply 12, the signal at the output of protection unit 2 is absent, and from converter 4 output, the signal goes through logical inverter 15 to R-input of trigger 16. At the output of the second filter 13 of the direct sequence, when the switching device is off, 1 signal equals zero, and at the output of the logical inverter 14 logical 1. This signal arrives at the S input of the RS flip-flop 16, the output of which generates a signal of logic 1 fed to the first inputs of blocks 3 and 6. The second and third inputs of the starting block 3 These do not come in. Under these conditions, the switching device 1 is turned on. After switching on the switching apparatus

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Output 1 at the output of filter 13 appears a signal that is inverted by an inverter 14, from the output of which the logical O signal is sent to the S input of the RS flip-flop 16, which, when a logical O signal arrives at both inputs, saves the previous state, t . the signal is logical 1 and the switching device 1 remains in the on state.

When the voltage at the power source 12 disappears, the switching device 1 is turned off. Due to the presence of residual EMF at the terminals of the electric motor 10 at the S-input of the RS-flip-flop, a logical O signal is stored for a while, while the R-in signal receives a logical 1 signal and the output of the flip-flop signal becomes equal to logical O.

After restoring the voltage of the power supply 12, the RS flip-flop 16 retains the previous state before the residual emf decays. After the residual EMF is completely attenuated at the terminals of the electric motor 10, the logical O and 1, respectively, are received at the R and S inputs of the RS flip-flop 16, and the logic 1 signal generated at the output of the flip-flop 16 is automatically switched on

When an abnormal operation of the electric motor 10 occurs at a normal voltage of the power supply 12, for example, a mode of current overload, the output of the protection unit 2 is fed to the input of the Switching unit 6, which, when a logical signal 1 is present, sends an output signal to the RS-flip-flop 16 The input of the accident memorizing unit 7 and to the starting unit 3, which switches off the electric motor 10 by means of a switching device, the inhibit signal from the accident memorizing unit 7 after switching off the electric motor 10 continues to flow to the starting unit 3 automatic

reclosing does not occur. Compiled by

Editor A. Kozoriz Tehred M. Ho

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When an abnormal mode of operation of the electric motor 10 occurs, for example, an overcurrent mode with an increased or decreased voltage of the power supply 12, the output of the protection unit 2 is fed to the input of the switching unit 6, which in the presence of a logic signal O from the output of the RS flip-flop 16 outputs the signal directly to the block 3, which by means of the crushing switch 1 turns off the electric motor 10. Block 7 does not work in this mode. After the normal voltage of the power supply source 1-2 is restored and the residual EMF is completely attenuated, the signal of the logical 1 is set at the terminals of the electric motor 10 on the code of the RS flip-flop 16, and the automatic switching on of the switching device 1 is performed.

Claims (1)

25 claims A device for automatic re-activation of an asynchronous electric motor according to auth.St. No. 660140, ditch characterized in that, in order to increase the reliability of the self-start by automatically changing the time interval until the motor is turned on again, determined by the total attenuation time of the residual EMF, the first and second inverters, short-circuit trigger and second voltage filter of the direct sequence, whose input is introduced; it is intended to be connected to the terminals of an asynchronous electric motor, with a continuous-to-discrete converter with an adjustable pickup zone connected to the start-up inputs the block and the switching unit through the first inverter n the RS flip-flop so that the output of the first inverter is connected to the K-input of the RS flip-flop. The S input of which is connected to the output of the second direct voltage voltage filter through the second inverter. Proofreader T.Malets