An input switch control method applied to forced air cooling of a pumped storage SFC system body

Abstract

The application relates to the technical field of starting of pumped storage units, in particular to an input switch control method applied to forced air cooling of a pumped storage SFC system body, comprising a SFC system, a pumped storage unit and an excitation system which are electrically connected with the SFC system respectively, wherein the SFC system comprises S1 switches, S2 switches, an input ICB switch and an output OCB switch, the input ICB switch is in a normally closed state, and an input transformer of the SFC system is always in a pressure-bearing state; the input ICB switch is long-term closed by the application and is in a normally closed state, so that the impact of unit starting on the transformer is avoided every time, and the reliability of equipment is improved.

Description

Technical Field

[0001] This application relates to the technical field of pumped storage unit startup, and in particular to an input switch control method for forced air cooling of the pumped storage SFC system. Background Technology

[0002] Pumped storage units (SFCs) experience frequent operating condition changes during operation. Each time the pump starts, the input circuit breaker needs to be closed, energizing the input transformer. After the pump stops operating, the circuit breaker is opened, de-energizing the input transformer. Therefore, the SFC equipment is frequently subjected to shocks during pumping startup, which negatively impacts the health of the SFC input transformer, SFC input circuit breaker, and other related equipment. This can easily lead to the following faults:

[0003] 1. The DC resistance of the SFC input transformer exceeds the standard;

[0004] 2. The input transformer nut is loose and discharging, and the acetylene content in the oil exceeds the standard;

[0005] 3. Frequent operation of the SFC input circuit breaker may cause faults in the circuit breaker's open / close position and the trolley position signals, resulting in unsuccessful unit startup. Summary of the Invention

[0006] To avoid impact on the transformer during each unit startup and improve equipment reliability, this application provides an input switch control method for forced air cooling of the pumped storage (SFC) system. The technical solution is as follows:

[0007] An input switch control method for forced air cooling of a pumped storage SFC system includes an SFC system and a pumped storage unit and an excitation system electrically connected thereto. The SFC system includes an S1 switch, an S2 switch, an input ICB switch, and an output OCB switch.

[0008] The input ICB switch is normally closed, and the input transformer of the SFC system is always under voltage.

[0009] Optionally, the startup control method of the SFC system is as follows:

[0010] (1) The SFC system enters the startup mode, the SFC system starts the self-test logic program, and the SFC system sends a connection signal;

[0011] (2) The pumped storage unit sends a connection success signal, and the SFC system sends an S2 switch closing command to start the program;

[0012] (3) The SFC system issues an OCB switch closing command to start the procedure;

[0013] (4) The SFC system issues an excitation release command and starts the rotor position measurement program;

[0014] (5) The SFC system releases a synchronization request, and the pumped storage unit issues a synchronization closing command;

[0015] (6) The SFC system issues an OCB switch opening command; the SFC system issues an S1 switch opening command and an S2 switch opening command.

[0016] Optionally, in step (4), when the motor speed of the pumped storage unit is greater than M% of the rated operating speed of the unit, the SFC system issues a lockout pulse signal and an S2 switch opening command, and simultaneously issues an S1 switch closing command to connect to the output transformer.

[0017] Optionally, M% ≥ 10%.

[0018] Optionally, in step (2), the SFC system starts auxiliary equipment, which includes cooling fans, bridge fans, reactor fans and machine bridge fans.

[0019] Optionally, the input ICB switch controls the disconnection of the input circuit breaker, and the output OCB switch controls the disconnection of the output circuit breaker.

[0020] In summary, this application has the following beneficial effects:

[0021] 1. For equipment using SFC body with forced air cooling, the long-term live operation mode is adopted, that is, the input circuit breaker is always closed and in the normally closed state, and the input transformer is always in the live state, which avoids the impact on the transformer every time the unit starts up and improves the reliability of the equipment.

[0022] 2. The input circuit breaker is kept closed for extended periods, avoiding frequent operation of the SFC input circuit breaker and reducing the probability of unit startup failure due to circuit breaker malfunction. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the SFC startup process in this embodiment;

[0024] Figure 2 This is a schematic diagram of the SFC shutdown process in this embodiment;

[0025] Figure 3 This is a schematic diagram of the circuit connection structure in this embodiment.

[0026] Explanation of reference numerals in the attached diagram: DO, SFC system; DI, pumped storage unit. Detailed Implementation

[0027] The following is in conjunction with the appendix Figure 1-3This application will be described in further detail.

[0028] This application discloses an input switch control method for forced air cooling of a pumped storage SFC system, comprising an SFC system, a pumped storage unit, and an excitation system. The SFC system is electrically connected to the pumped storage unit and the excitation system. The SFC system includes an S1 switch, an S2 switch, an input ICB switch, an output OCB switch, an input transformer, a network bridge, a DC reactor, a mechanical bridge, an output transformer, an output AC reactor, a GCB switch, and a starting bus. The input ICB switch and the network bridge are electrically connected to the input transformer, the network bridge and the mechanical bridge are electrically connected to the DC reactor, the mechanical bridge and the output OCB switch are electrically connected to the output transformer, the S1 switch and the S2 switch are electrically connected to the output transformer and serve as output transformer activation control switches, the output OCB switch and the starting bus are electrically connected to the output AC reactor, and the GCB switch is used for opening and closing relay contacts.

[0029] In this embodiment, ICB refers to the input circuit breaker and OCB refers to the output circuit breaker.

[0030] like Figure 1 As shown, the startup process of the SFC system is as follows:

[0031] (1) When the SFC system enters the startup mode, the SFC system starts the self-test logic to check whether the SFC system is available (the SFC system has no warnings, no faults, and no external trips). When the SFC system is available, it enters the preparation work before startup. When the SFC system is in standby state, the OCB switch, S1 switch, S2 switch and GCB switch are in the open position, and the ICB switch is in the closed position.

[0032] (2) The SFC system sends a start-up preparation completion signal to the pumped storage unit. After the pumped storage unit selects a motor to connect to the SFC system, the pumped storage unit sends a start command to the SFC system. After receiving the start command, the SFC system issues an S2 switch closing command and a fan start command. At this time, the S1 switch is in the open state.

[0033] (3) The SFC system enters the startup procedure and sends a startup command to the pumped storage unit to start the auxiliary equipment of the pumped storage unit. The auxiliary equipment includes cooling fans, grid bridge fans, reactor fans and machine bridge fans. The pumped storage unit sends grid bridge fan operation signal, reactor fan operation signal, machine bridge fan operation signal and S2 switch closing position. The SFC system sends OCB switch closing command to start the procedure. The pumped storage unit sends OCB closing, ICB closing and grid bridge anode voltage normal signals.

[0034] (4) After receiving the SFC start command from the SFC system, the SFC system immediately sends a release command to the excitation system. At this time, the excitation system starts and applies excitation current to the pumped storage unit. At the same time, it sends a feedback signal to the SFC system that the excitation system has been released. After receiving the excitation signal, the SFC system immediately starts measuring the initial position of the rotor of the pumped storage unit and then drives the pumped storage unit up.

[0035] (5) When the motor of the pumped storage unit enters the motor rotation pulse commutation stage, when the motor speed of the pumped storage unit is greater than 1% of the rated operating speed of the pumped storage unit, the pumped storage unit sends a feedback signal and the SFC system works normally.

[0036] (6) When the motor speed of the pumped storage unit is greater than 10% of the rated operating speed of the pumped storage unit, the SFC system issues a lockout pulse signal and an S2 switch opening command, the pumped storage unit issues an S2 switch opening position, and the SFC system issues an S1 switch closing command to connect to the output transformer for voltage regulation and deceleration.

[0037] (7) When the pumped storage unit enters the unlocking pulse motor acceleration load commutation stage, when the motor of the pumped storage unit is greater than the set value of the rated operation of the pumped storage unit, the pumped storage unit requests synchronization and enters the automatic quasi-synchronous operation state. The SFC system responds to the synchronization request and enters the synchronization adjustment mode stage. The SFC system receives the frequency increase / decrease signal sent by the synchronization device of the pumped storage unit and adjusts the speed of the pumped storage unit until it is connected to the grid.

[0038] (8) When the pumped storage unit issues a synchronization closing command or controls the GCB switch to close position, after the SFC system receives the signal from the pumped storage unit switch closing position contact or closing relay contact, the SFC system will lock the output current and then the SFC system will enter the shutdown process.

[0039] like Figure 2 As shown, the shutdown procedure for the SFC system is as follows:

[0040] (1) The SFC system blocks the output current, and then the SFC system issues an OCB output switch opening command, and the pumped storage unit issues an OCB output switch opening position.

[0041] (3) When the SFC system switches off, the SFC system issues the S1 switch off order and the S2 switch off order, and stops the SFC system. The pumped storage unit detects the S1 switch off position and the S2 switch off position, and issues the fan stop order to stop the operation of the auxiliary equipment.

[0042] (4) The SFC system receives the stop signal of the grid bridge fan, the stop signal of the reactor fan and the stop signal of the machine bridge fan from the pumped storage unit and enters the standby state.

[0043] The control method in this embodiment uses an ICB switch that is always in the closed position, and the input circuit breaker is always closed. When the pumped storage unit starts operating, the input transformer is in a energized state, and there is no need to operate the ICB switch to close the circuit breaker, thus avoiding the impact on the transformer every time the unit starts. After the operating condition ends, there is no need to operate the ICB switch to open the circuit breaker, and the input transformer is always in a energized state. After one motor starts, the SFC system enters a standby state and can continue to start another motor in the pumped storage unit or continue to start another pumped storage unit. During this process, the ICB switch is always in the closed position.

[0044] During the pumping operation of the pumped storage unit, from start-up to end, the ICB switch of the SFC system is always in the closed position, and the input transformer is always under voltage. This avoids the SFC system being frequently impacted during the pumping start-up process, improves the reliability of the SFC system, and avoids the phenomenon of unit start-up failure due to frequent operation of the SFC input circuit breaker causing circuit breaker open / close position or handcart position signal failure.

[0045] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An input switch control method applied to forced air cooling of a pumped storage SFC system body, characterized in that: The SFC system comprises S1 switch, S2 switch, input ICB switch and output OCB switch, ICB means input circuit breaker, and OCB means output circuit breaker; The input ICB switch is in a normally closed state, and the input transformer of the SFC system is always in a pressure-bearing state; The starting control method of the SFC system is as follows: (1) The SFC system enters a starting mode, the SFC system starts a self-checking logic program, and the SFC system sends a connection signal; (2) The pumped storage unit sends a connection success signal, the SFC system sends a S2 switch closing order to start the program; (3) The SFC system sends an OCB switch closing order to start the program; (4) The SFC system sends a field release instruction, and the SFC system starts a rotor position measurement program; (5) The SFC system releases a synchronization request, and the pumped storage unit sends a synchronization closing order; (6) The SFC system sends an OCB switch opening order, the SFC system sends a S1 switch opening order and a S2 switch opening order.

2. The input switch control method applied to the forced air cooling of the body of the pumped storage SFC system according to claim 1, characterized in that: In step (6), when the motor rotating speed of the pumped storage unit is greater than 10% of the rated rotating speed of the unit, the SFC system sends a locking pulse signal and a S2 switch opening order, and simultaneously sends a S1 switch closing order to connect the output transformer.

3. The input switch control method applied to the forced air cooling of the body of the pumped storage SFC system according to claim 1, characterized in that: In step (2), the SFC system starts auxiliary equipment, and the auxiliary equipment comprises cooling fan, network bridge fan, electric reactor fan and machine bridge fan.

4. The input switch control method applied to the forced air cooling of the body of the pumped storage SFC system according to claim 1, characterized in that: The input ICB switch controls the connection of the input circuit breaker, and the output OCB switch controls the connection of the output circuit breaker.

Images