SU1621120A2 - Method of automatic control of fail-safe power supply system - Google Patents

Abstract

The invention relates to energy and can be used in power supply systems containing a reversible electric machine with an inertial flywheel and excitation control.

Description

The invention relates to power engineering, namely to emergency control of power systems, and can be applied to power systems containing a reversible electric machine with an excitation controller and an inertia flywheel mechanically connected by means of an uncoupling coupling to the primary internal combustion engine and connected in parallel network input to the tires of guaranteed power.

The purpose of the invention is to preserve the resource of the drive engine and improve the quality of the voltage on the tires of the guaranteed power supply in dynamic modes of operation.

The drawing shows a diagram of the device that implements the proposed method.

Network input 1 using the switch 2 of the network input is connected to the bus 3 of the guaranteed power supply. Parallel to the mains input, a reversible electric machine 5 with an inertial flywheel 6 is connected to the buses of the guaranteed power supply through the switch 4. The primary engine 8 is connected to the reversible electric machine 5 via the disconnecting plug 7 to the driving motor of which is connected to the reversible electric machine relay 10 for starting the drive motor, connected to voltage regulator 11, to which voltage corrector 13 is connected via electronic switch 12. Parallel to the field winding 9, the first 14 m second 15 threshold elements are connected. The control circuit also contains the first NOT circuit 16, the closing contact 17 of the start relay 10, the time element 18, the first circuit AND 19, the second circuit NOT 20, the first RS flip-flop 21, the second circuit AND 22, the second RS-flip-flop 23, the third AND circuit 24, OR circuit 25. The output of the first threshold element 14 is directly connected to one of the inputs of the first 19 and third 24

And circuits to the input of the second circuit is NOT 20, and through the closing contacts 17 of the start relay 10 to the R inputs of the first 21 and second 23 RS triggers. The output of the second threshold element 15 is connected to the input of the first circuit NOT 16 and to one of the inputs of the circuit OR 25. The output of the first circuit NOT 16 is connected to the second input of the first circuit And 19, the output of which is connected to the S-input of the first RS flip-flop 21. Unit output the first RS flip-flop 21 is connected to one of the inputs of the second circuit AND 22, to the other input of which the output of the second circuit is NOT 20. The output of the second circuit AND 22 is directly connected to the S-input of the second RS-flip-flop 23 to the control input of the electronic key 12 , and through the time element 18 to the electromagnet off switch 4. The single output of the second RS flip-flop 23 is connected to another input of the third circuit AND 24, the output of which is connected to another input of the circuit OR 25. The output of the circuit OR 25 is connected to the shut-off electromagnet of the switch 2 of the network input and to the start relay 10, which provides start prime mover 8.

The voltage measuring circuits of the unit 26 for detecting the operating modes of the reversible electric machine and the excitation controller 11 are connected to the buses of the guaranteed power supply and to the output terminals of the reversible electric machine. The first input of the voltage corrector 13 is connected to the voltage measuring circuit of a reversible electrical machine, and the second input to the outputs of the second 27 and third 28 electronic switches connecting the outputs of the feedback current sensor 29 to the voltage corrector 13. Sensor 29 is connected in parallel to the field winding of a reversible electric machine. The control inputs of the second 27 and third 28 electronic keys are connected to the output of the operating mode detection unit 26 of the reversible electric machine, the control input of the second electronic key 27 is connected directly, and the control input of the third electronic key 28 is turned on via the third circuit NOT 30, input which is connected to the output of the block 26. The output of the block 26 is also connected to the disconnecting electromagnet switch 2 of the network input and to the relay 10 of the start of the drive engine 8.

The units included in the device perform the following functions.

Network input 1 with switch 2, tires 3 with guaranteed power supply, reversible electric machine 5 with inertial flywheel 6, connected through disconnecting coupling 7 with primary engine 8 and connected to buses with guaranteed power supply of switches 4, form a guaranteed power supply, Excitation winding 9 with adjustable excitation torus 11, voltage corrector 13 and electronic key 12 form a controlled excitation regulator of a reversible electric machine. The first 14 and second 15 threshold elements form a voltage meter in the field of the excitation winding containing the limiters for the minimum and maximum voltage values.

The first NOT circuit 16 is shared by the first circuit AND 19 and the first RS flip-flop 21 to form a memory element fixing that the magnitude of the voltage in the field of the excitation winding is in the range of acceptable values. The second HE 20 circuitry, together with the second circuit 22, provides control of the electronic key 12 in the case where the voltage in the field of the excitation winding is less than the allowable value. In this case, the HE 20 and AND 22 circuits ensure that the voltage corrector 13 is disconnected from the excitation regulator, thereby creating the opportunity for increasing the voltage in the excitation winding circuit. Determining the magnitude of the voltage after turning off the voltage corrector makes it possible to establish the reason for the decrease in the voltage in the field circuit. If the excitation voltage is restored, then the decrease in the voltage in the field of the excitation winding is unacceptable: a large value of the voltage of the main source, as a result of which the voltage corrector reduced the voltage at the output of the excitation regulator to a minimum. If the excitation voltage is not restored, then the reason for the decrease in voltage on the tires of the guaranteed power supply is a short circuit in the circuit of the reversible electric machine. The time element T8 provides a time delay.

necessary to complete transients in the excitation circuit. The second RS trigger 23 and the third circuit And 24 provide for the disconnection of the network input 1 and the start

5 of the prime mover 8 with the help of the start-up relay 10 with an unacceptably large amount of voltage of the main source. The closing contacts 17 of the relay 10 start provide the return of RS-flip-flops 21 and 23 to zero

The 0 state at the start of the prime mover and thereby prevents false triggering of the control circuit. The feedback current value sensor 29 from the output of the excitation controller, together with the second 27 and third 28 electronic switches and the third 30 circuit, do NOT form a controlled feedback circuit of the voltage regulator corrector corrector. The current transformer 31 is connected to the output

0 stator winding reversible electric machine.

The device works as follows.

5 In the normal mode of operation, the electric power is supplied to the buses 3 of guaranteed-power through the switch 2 of the mains input from the main source 1. Reversible electrical machine 5 through its

0, the switch 4 is connected to the guaranteed power lines and rotates the flywheel 6. The coupling 7 is disconnected and the prime mover 8 is ready to start. Winding 9 excitation reversible

5 of the electric machine is connected to the output of the excitation controller 11, the operation of which is controlled via the open electronic switch 12 by the voltage corrector 13. The voltage in the excitation winding circuit 9 is in the range of allowable values at which the first threshold element 14 is opened and the second threshold element 15 is closed. A voltage from the output of the first threshold element 14 to 5 is supplied to one of the outputs of the first 19 and third 24 And circuits To the input of the second circuit is NOT 20. To the other input of the first circuit, And 19, a signal is received from the output of the first circuit, NOT 16, the output of this circuit is voltage

0 because the second threshold element 15 is closed, which means that no voltage is applied to the input of the first circuit NOT 16. The signal from the output of the first circuit AND 19 is fed to the S input of the first RS flip-flop 21 and translates this

5 trigger into a single state at its direct output, preparing the second circuit AND 22 for triggering. The first RS flip-flop, 21 detects the presence of a normal mode of operation of the unit of guaranteed power supply.

In the considered system operation mode at the output of the block 26 for detecting the operating modes of the reversible electric machine, there is no signal. At the same time, the feedback circuit through the third electronic key 28, opened by a signal from the output of the third circuit NOT 30, is connected to the input of the voltage corrector 13 so that it provides maximum statism. Changes in the voltage of the network input are perceived and smoothed by a reversible electric machine, while its rotor circuits are prepared for the dynamic processes taking place and are not overloaded.

When the voltage of the main source decreases, the reversible electric machine switches to the synchronous compensator mode and starts generating reactive energy to the external network. In this case, the voltage at the terminals of its excitation winding increases. In the case when the voltage of the main source has decreased so much that it has gone beyond the range of acceptable values or has disappeared altogether, the voltage in the field of the excitation winding exceeds the allowable value, and the second threshold element 15 opens. The voltage from its output goes to the first circuit NOT 16 and one of the inputs of the circuit OR 25. At the same time, the voltage at the output of the circuit NOT 16 disappears, but the first RS flip-flop 21 remains in one state.

A signal from the output of the OR circuit 25 is applied to the disconnecting solenoid of the power switch 2 and to the start relay 10. The power switch 2 disconnects the main source from the busses of guaranteed power supply, and the start-up relay 10 triggers the start of the prime mover 8. During the start of the prime mover 8, power is supplied to the power supply buses from a reversible electric machine 5 driven by an inertial flywheel 6. at the rated speed of the prime mover 8, the disconnecting clutch 7 is turned on and the drive of the reversible electric machine starts-carried out from the prime mover. The activation of the start-up relay 10 activates its closing contact 17, through which the signal from the output of the first threshold element 14 enters the RS-inputs of the first 21 and second 23 RS-flip-flops, which then switch to the zero state.

At the moment of the transition of the reversible electric machine to the synchronous generator mode, a signal appears at the output of the operation detection unit 26. Wherein

the network input switch 2 is turned off, the command to start the drive motor is given, the third electronic key 28 is closed and the second electronic key is opened

key 27, thereby turning on the feedback circuit to the input of the voltage corrector and setting the minimum excitation control statistics.

When the voltage in the excitation circuit 9 is lowered below the permissible value, the first threshold element 14 closes and the voltage at its output disappears. A signal appears at the output of the second circuit NOT 20, the input of which is under the 5 keys to the output of the first threshold element 14. The output from the circuit output HE 20 is fed to the second input of the second circuit AND 22. At the first circuit input there is a signal from the output of the first RS- a trigger that remembers that the voltage in the excitation circuit was within the permissible range. If the start mode of the installation of guaranteed power supply takes place, the appearance of the signal at the output of the second circuit is NOT 20

5 to triggering the second circuit AND 22, since the first RS flip-flop is in the zero state. The operation of the second circuit And 22 provides locking of the electronic key 12 and thereby disabling the corrector

0 13 voltages from excitation controller 11. Simultaneously with the locking of the electronic key 12, the time element 18 is started and the second RS flip-flop 23 is switched to the single state, preparing the operation of the third I24 circuit. If the cause of a sharp decrease in the voltage in the field of the excitation winding was an increase in the voltage of the main source, then after turning off the voltage corrector 13, the voltage in the field of the excitation winding increases, the first threshold element 14 opens, the output of which is the voltage. In this case, the signal from the output of the second circuit NOT 20 disappears, and therefore, the signal disappears from the output of the second circuit And 22, thereby stopping the operation of the time element 18 and removing the locking signal from the input of the electronic key 12. At the same time, the signal from the output of the first

0 of the threshold element 14 is supplied to the second input of the third circuit AND 24, which provides through the circuit OR 25 a shutdown of the network input switch 2 and the activation of the starting relay 10 of the primary motor 8. The signal from the output of the first threshold element 14 transfers the first 21 and The second 23 RS-triggers in the zero state, blocking the repeated shutdown of the voltage corrector. The time delay of time element 18 is selected.

longer than the time of electromagnetic transients of the excitation controller and the excitation winding. In the case when the cause of a sharp decrease in the voltage in the excitation winding circuit is a short circuit in the stator circuit of a reversible electric machine 5, then after the voltage corrector 13 is disconnected, the voltage in the excitation winding circuit is not restored and at the output of the first threshold element 14 life does not occur. After the time delay of the time element 18 has elapsed, the voltage from the output of this element is supplied to the electromagnet off switch 4 of the reversible electric machine, which is then disconnected from the tires of the guaranteed power supply 3 and then stops.

The invention allows a reversible electric machine to operate in a synchronous compensator mode when the voltage of a network input varies widely, thereby preserving the life of the drive motor and improving the quality of the voltage on the tires of guaranteed power in dynamic operating modes.

Saving the drive motor resource and improving the quality of voltage in dynamic modes of operation allows increasing the reliability of the guaranteed power supply system, extending its service life and eliminating possible failures and malfunctions of the equipment connected to the guaranteed power supply buses.

If, in the operation mode of the synchronous compensator, the characteristic of the voltage corrector and excitation regulator does not change and does not establish maximum statism, then during voltage fluctuations of the feed input, the rotor circuits of the reversible electric machine will overload and the reversible electric machine will start up drive engine In this connection, due to frequent start-ups, the life of the system of guaranteed power supply, determined by the number of starts of the drive engine, is expended. When a reversible electric machine operates in the synchronous compensator mode with maximum statism, its rotor circuits are prepared for possible voltage fluctuations of the network input and the network input switch will not be disconnected, therefore the drive motor and the reversible electric machine will not be required to remain in the synchronous compensator mode will help equalize the voltage on the tires of a guaranteed power supply.

Claims (1)

The invention The method of automatic control of the system of guaranteed power supply by aut. St. No. 1348949, characterized in that, in order to preserve the resource of the drive motor and improve the quality of the voltage on the guaranteed power supply tires in dynamic operating modes, the operating mode of the reversible electric machine is determined and, in the synchronous compensator mode, the characteristic of the voltage corrector and the excitation regulator , set the maximum statism and fix the nominal voltage setting so that the nominal voltages correspond to the 50% load, and in the synchronous generator mode they are set to minimum statism, keeping the nominal voltage setting unchanged for 50% load.