Auxiliary power three power supply switching system and control method, system device and medium

Abstract

The application discloses a kind of plant electricity three power supply switching system and its control method, system device and medium, including two unit generator systems, four switching devices, a high-voltage standby transformer and a standby variable public section bus, each unit generator system includes a high-voltage plant transformer and two working buses, each high-voltage plant transformer provides working power supply for two working buses, the high-voltage standby transformer is connected with standby variable public section bus, and the standby variable public section bus is divided into two branches, each branch provides standby power supply for two working buses, the working bus of high-voltage plant transformer and high-voltage standby transformer connection is different, and two high-voltage plant transformers can also be standby power supply for each other.The embodiment of the application can reduce the number of switching devices, reduce the amount of purchased electricity, improve the safety and economy of the system, and can be widely applied in the field of power generation technology.

Description

Technical Field

[0001] This invention relates to the field of power generation technology, and in particular to a three-power switching system for plant power supply, its control method, system device, and medium. Background Technology

[0002] With changes in the electricity market, on the one hand, the electricity price charged by the power grid to high-voltage standby transformers is far higher than the power plant's own generation cost; on the other hand, frequent unit shutdowns and increased external purchases of power consumption will inevitably generate substantial external electricity costs, directly impacting economic efficiency. In response to government requirements for energy conservation and emission reduction, and to save production costs, more and more power plants are undertaking high-voltage power supply interconnection projects. This involves interconnecting the working sections of two generating units to ensure that during startup and maintenance shutdowns, most of the power consumption for the plant is supplied by the other unit. Compared to before, the plant power supply wiring after the interconnection project includes an additional tie power supply line in addition to the working power supply line and the standby power supply line, thus placing higher demands on the plant power supply switching device.

[0003] In related technologies, plant power switching devices only switch between two power sources. For plant power wiring schemes without plant power interconnection, the plant power switching device controls the closing of the working power input switch and the backup power input switch by monitoring the voltage and phase angle of the working power input line, the backup power input line, and the busbar to achieve plant power switching between the high-voltage plant transformer and the high-voltage backup transformer. Under the traditional plant power interconnection wiring scheme, to achieve plant power switching using a traditional plant power switching device, an additional plant power switching device needs to be installed. One switching device controls the closing of the working power input switch and the backup power input switch by monitoring the voltage and phase angle of the working power input line, the backup power input line, and the busbar, while the other switching device controls the closing of the backup power input switch and the tie power input switch by monitoring the voltage and phase angle of the backup power input line, the tie power input line, and the busbar. Combining the above logic to achieve plant power switching results in a large investment in equipment and cables, and the control logic is relatively complex. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a three-power switching system for plant power supply, its control method, system device and medium, which can reduce the number of switching devices, reduce the amount of purchased electricity, and improve the safety and economy of the system.

[0005] In a first aspect, embodiments of the present invention provide a three-power switching system for plant auxiliary power, comprising two unit generator systems, four switching devices, one high-voltage standby transformer, and a common busbar section for the standby transformer. Each unit generator system includes one high-voltage plant auxiliary transformer and two working busbar sections. The first high-voltage plant auxiliary transformer is connected to the first working busbar section via a first power input switch, the first high-voltage plant auxiliary transformer is connected to the second working busbar section via a second power input switch, the second high-voltage plant auxiliary transformer is connected to the third working busbar section via a third power input switch, and the second high-voltage plant auxiliary transformer is connected to the fourth working busbar section via a fourth power input switch. The low-voltage side of the high-voltage standby transformer... The spare transformer common section bus is connected via a spare incoming line switch. The spare transformer common section bus is connected to the first working bus via a first feeder switch and a fifth power incoming line switch. The spare transformer common section bus is connected to the third working bus via the first feeder switch and a sixth power incoming line switch. The spare transformer common section bus is connected to the second working bus via a second feeder switch and a seventh power incoming line switch. The spare transformer common section bus is connected to the fourth working bus via the second feeder switch and an eighth power incoming line switch. All working buses, the spare transformer common section bus, all power incoming line switches, and all feeder switches are connected to any one of the four switching devices.

[0006] Secondly, embodiments of the present invention provide a control method for a three-power supply switching system for plant power, applied to the aforementioned switching system, comprising:

[0007] Control the first power input switch and the first feeder switch to be closed, and control the fifth power input switch to be open, so that the first high-voltage plant service transformer supplies power to the first section of working bus, and the switching device enters the fault monitoring state.

[0008] If a fault signal is detected in the first working busbar, the first power input switch is closed, the fifth power input switch is open, and the voltage output from the standby transformer common busbar is qualified, the first power input switch is controlled to be open and the fifth power input switch is controlled to be closed.

[0009] If a fault signal is detected in the first power input switch, the first power input switch is closed, the fifth power input switch is open, and the voltage output from the common bus of the standby transformer is qualified, the first power input switch is controlled to open and the fifth power input switch is controlled to close.

[0010] Optionally, the method further includes:

[0011] If the first power input switch is closed, the fifth power input switch is open, and the voltage output from the common bus of the standby transformer is qualified, a switching signal is detected, and the fifth power input switch is controlled to close and the first power input switch is opened.

[0012] Optionally, the method further includes:

[0013] If the first power input switch is open, the fifth power input switch is closed, and the voltage output by the first high-voltage plant transformer is qualified, a switching signal is detected, and the first power input switch is controlled to close and the fifth power input switch is open.

[0014] Optionally, the method further includes:

[0015] If the first power supply incoming switch is closed and the first high-voltage plant service transformer is energized, the fifth power supply incoming switch is open, the first feeder switch is closed and the standby transformer common section busbar is energized, and the sixth power supply incoming switch is open;

[0016] Control the fifth power input switch to be closed and the first feeder switch to be open, so that the first section of working busbar can be used as a backup for the third section of working busbar.

[0017] Optionally, the method further includes:

[0018] If the first power supply incoming switch is closed and the first high-voltage plant service transformer is energized, the fifth power supply incoming switch is closed, the first feeder switch is open and the standby transformer common section busbar is energized, and the sixth power supply incoming switch is open;

[0019] Control the first feeder switch to be closed and the fifth power input switch to be open, so that the spare transformer common section busbar can be used as a backup for the third working section busbar.

[0020] Optionally, the method further includes:

[0021] If the first power supply incoming switch is closed and the first high-voltage plant service transformer is energized, the fifth power supply incoming switch is open, the first feeder switch is closed and the standby transformer common section busbar is energized, and the sixth power supply incoming switch is closed;

[0022] Control the fifth power input switch to be closed and the first feeder switch to be open, so that the first working busbar supplies power to the shutdown load of the third working busbar.

[0023] Thirdly, embodiments of the present invention provide a control system for a three-power supply switching system for plant power, comprising:

[0024] The first module is used to control the first power input switch and the first feeder switch to be closed, and to control the fifth power input switch to be open, so that the first high-voltage plant service transformer supplies power to the first section of working bus, and the switching device enters the fault monitoring state.

[0025] The second module is used to control the first power input switch to open and the fifth power input switch to close if a fault signal is detected in the first working bus, the first power input switch is closed, the fifth power input switch is open, and the voltage output of the standby transformer common bus is qualified.

[0026] The third module is used to control the first power input switch to open and the fifth power input switch to close if a fault signal is detected in the first power input switch, the first power input switch is closed, the fifth power input switch is open, and the voltage output from the common bus of the standby transformer is qualified.

[0027] Fourthly, embodiments of the present invention provide a control device for a three-power supply switching system for plant power, comprising:

[0028] At least one processor;

[0029] At least one memory for storing at least one program;

[0030] When the at least one program is executed by the at least one processor, the at least one processor performs the method described above.

[0031] Fifthly, embodiments of the present invention provide a computer-readable storage medium storing a processor-executable program, which, when executed by a processor, is used to perform the methods described above.

[0032] Implementing this embodiment of the invention has the following beneficial effects: The three-power switching system for plant power in this embodiment includes two unit generator systems, four switching devices, one high-voltage standby transformer, and one standby transformer common busbar. Each unit generator system includes one high-voltage plant power transformer and two working busbars. The standby transformer common busbar is connected to the first working busbar through the first feeder switch and the fifth power input switch. The standby transformer common busbar is connected to the third working busbar through the first feeder switch and the sixth power input switch. That is, the standby transformer common busbar provides backup power to the first working busbar through the first feeder switch and the fifth power input switch. The first working busbar and the third working busbar form a backup power supply to each other through the fifth power input switch and the sixth power input switch. The two backup power supplies of the first working busbar—the standby transformer common busbar and the third working busbar—share a power input switch and circuit. Therefore, only one switching device is needed for the working and backup power input lines of each working bus, thereby reducing the number of switching devices and simplifying the wiring and control logic. If a fault signal occurs in the first working bus or the first power input switch, the backup transformer common section bus can be used to provide backup power to the first working bus by controlling the first power input switch and the fifth power input switch. If the high-voltage backup transformer or the backup transformer common section is under maintenance, the first working bus can be used to provide backup power to the third working bus by controlling the first feeder switch and the fifth power input switch. If the second unit generator system shuts down, the first working bus can be used to supply power to the shutdown load of the third working bus by controlling the first feeder switch and the fifth power input switch. This enables flexible control of the high-voltage backup transformer and the high-voltage plant service transformer and the plant service interconnection in the three-power switching system for plant power, improving the safety and economy of the system. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a three-power supply switching system for plant power provided in an embodiment of the present invention;

[0034] Figure 2 This is a flowchart illustrating the steps of a control method for a three-power switching system for plant power provided in an embodiment of the present invention.

[0035] Figure 3 This is a structural block diagram of the control system of a three-power switching system for plant power provided in an embodiment of the present invention;

[0036] Figure 4 This is a structural block diagram of a control device for a three-power switching system for plant power provided in an embodiment of the present invention. Detailed Implementation

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only for ease of explanation and do not limit the order of the steps. The execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art.

[0038] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0039] In the following description, the terms "first, second, third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of the invention described herein can be implemented in an order other than that illustrated or described herein.

[0040] Unless otherwise defined, all technical and scientific terms used in the embodiments of this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in the embodiments of this invention is for descriptive purposes only and is not intended to limit the invention.

[0041] Before providing a further detailed description of the embodiments of the present invention, the nouns and terms involved in the embodiments of the present invention will be explained, and the nouns and terms involved in the embodiments of the present invention shall be interpreted as follows.

[0042] In related technologies, for the traditional plant power interconnection wiring scheme: based on the plant power interconnection scheme, the working busbars of two generating units are connected by a connecting cable. Each generating unit's working busbar has a connecting power supply incoming switch. In this case, the two generating units are interconnected, and the plant power for either unit can be supplied by its high-voltage transformer, switched to a high-voltage backup transformer for grid power, or supplied by another generating unit via the connecting cable. For a single working section busbar, due to the additional connecting power supply incoming line and its switch, two plant power switching devices are required. One switching device monitors the voltage and phase angle of the working power supply incoming line, the backup power supply incoming line, and the busbar to control the closing of the working power supply incoming line switch and the backup power supply incoming line switch. The other switching device monitors the voltage and phase angle of the backup power supply incoming line, the connecting power supply incoming line, and the busbar to control the closing of the backup power supply incoming line switch and the connecting power supply incoming line switch. The plant power switching is achieved by combining the above logic.

[0043] In a first aspect, embodiments of the present invention provide a three-power switching system for plant auxiliary power, comprising two unit generator systems, four switching devices, one high-voltage standby transformer, and a common busbar section for the standby transformer. Each unit generator system includes one high-voltage plant auxiliary transformer and two working busbar sections. The first high-voltage plant auxiliary transformer is connected to the first working busbar section via a first power input switch, the first high-voltage plant auxiliary transformer is connected to the second working busbar section via a second power input switch, the second high-voltage plant auxiliary transformer is connected to the third working busbar section via a third power input switch, and the second high-voltage plant auxiliary transformer is connected to the fourth working busbar section via a fourth power input switch. The low-voltage side of the high-voltage standby transformer... The spare transformer common section bus is connected via a spare incoming line switch. The spare transformer common section bus is connected to the first working bus via a first feeder switch and a fifth power incoming line switch. The spare transformer common section bus is connected to the third working bus via the first feeder switch and a sixth power incoming line switch. The spare transformer common section bus is connected to the second working bus via a second feeder switch and a seventh power incoming line switch. The spare transformer common section bus is connected to the fourth working bus via the second feeder switch and an eighth power incoming line switch. All working buses, the spare transformer common section bus, all power incoming line switches, and all feeder switches are connected to any one of the four switching devices.

[0044] Specifically, see Figure 1 The No. 1 high-voltage station service transformer provides power to the first working busbar section 1A via the first power incoming switch 1DL. The No. 1 high-voltage station service transformer provides power to the second working busbar section 1B via the second power incoming switch 2DL. The No. 2 high-voltage station service transformer provides power to the third working busbar section 2A via the third power incoming switch 1DL'. The No. 2 high-voltage station service transformer provides power to the fourth working busbar section 2B via the fourth power incoming switch 2DL'. The low-voltage side of the high-voltage standby transformer is connected to the standby transformer common section via a standby incoming switch. The busbars, including the standby transformer common section busbar, are connected to the first working busbar 1A section via the first feeder switch 10DL and the fifth power input switch 11DL. The standby transformer common section busbar is connected to the third working busbar 2A section via the first feeder switch 10DL and the sixth power input switch 12DL. The standby transformer common section busbar is connected to the second working busbar 1B via the second feeder switch 20DL and the seventh power input switch 21DL. The standby transformer common section busbar is connected to the fourth working busbar 2B via the second feeder switch 20DL and the eighth power input switch 22DL.

[0045] The wiring structure of the switching device is as follows Figure 1As shown, taking the 1A section busbar as an example, the following explanation is provided: The #1 unit's plant power switching device K1 collects and monitors the voltage and current (A4512, N4511, 1A630, 1B630) at the first power input switch 1DL, the voltage and current (A4622, N4621, 2A630, 2B630) at the fifth power input switch 11DL, the current (A4231, N4231) at the first feeder switch 10DL of the standby common section, the voltage (A630, B630, C630) of the first working busbar 1A section, and the voltage (A650, B650) of the standby common section busbar. At the same time, it collects the position signals of the first power input switch 1DL, the fifth power input switch 11DL, and the first feeder switch 10DL of the standby common section, and outputs the control to close the first power input switch 1DL, the fifth power input switch 11DL, and the first feeder switch 10DL of the standby common section.

[0046] Implementing this embodiment of the invention has the following beneficial effects: The three-power switching system for plant auxiliary power in this embodiment includes two unit generator systems, four switching devices, one high-voltage standby transformer, and one section of standby transformer common busbar. Each unit generator system includes one high-voltage plant auxiliary transformer and two sections of working busbar. The standby transformer common busbar is connected to the first section of working busbar through the first feeder switch and the fifth power input switch. The standby transformer common busbar is connected to the third section of working busbar through the first feeder switch and the sixth power input switch. The busbar provides backup power to the first working busbar through the first feeder switch and the fifth power input switch. The first working busbar and the third working busbar form a backup power supply to each other through the fifth power input switch and the sixth power input switch. The two backup power supplies of the first working busbar—the backup transformer common section busbar and the first working busbar share a power input switch and circuit. Therefore, only one switching device is needed for the working power input and backup power input of each working busbar, thereby reducing the number of switching devices and making the wiring and control logic simpler.

[0047] The control method of the three-power supply switching system for plant power is explained below, taking the first and third working busbars as examples.

[0048] See Figure 2 This invention provides a control method for a three-power supply switching system for plant power, applied to the aforementioned switching system, provided that the first feeder switch 10DL is always in the closed state, including steps S100 to S300.

[0049] S100: Control the first power input switch and the first feeder switch to be closed, and control the fifth power input switch to be open, so that the first high-voltage plant service transformer supplies power to the first section of working bus, and the switching device enters the fault monitoring state.

[0050] Specifically, see Figure 1 With the first power supply incoming switch 1DL in the closed position, the working power supply of the first high-voltage station service transformer supplies power to the first working busbar through the working branch. The first feeder switch 10DL is in the closed position, and the fifth power supply incoming switch 11DL of the standby branch is in the open position, providing backup power to the busbar through 10DL. After the switching system is powered on, if the voltage of the first working busbar and the standby incoming line is qualified and there is no incoming line fault, the system begins charging. After 10 seconds of charging, charging is complete, and the system enters fault monitoring mode. This situation is a normal operating scenario.

[0051] S200: If a fault signal is detected in the first working busbar, the first power input switch is closed, the fifth power input switch is open, and the voltage output of the standby transformer common busbar is qualified, control the first power input switch to open and the fifth power input switch to close.

[0052] Specifically, see Figure 1 After the system has completed power supply (input: bus TV in = closed position), if the system experiences bus voltage loss or circuit breaker tripping, the device will perform abnormal operating condition switching. The switching process is as follows: when the first power input switch 1DL is detected to be closed, the fifth power input switch 11DL is detected to be open, and the backup power supply voltage of the backup transformer common section bus is qualified, if the first section working bus is detected to be undervoltage or the first power input switch 1DL is detected to trip, then the first power input switch 1DL will be tripped again, and the fifth power input switch 11DL will be closed.

[0053] S300: If a fault signal is detected in the first power input switch, the first power input switch is closed, the fifth power input switch is open, and the voltage output from the common bus of the standby transformer is qualified, control the first power input switch to open and the fifth power input switch to close.

[0054] Specifically, see Figure 1 After the system completes power supply, if an incoming line fault is detected, an emergency switchover will be performed. The switchover process is as follows: when the first power incoming line switch 1DL is closed, the fifth power incoming line switch 11DL is open, and the backup power supply voltage of the backup transformer common section bus is qualified, if a first power incoming line fault is detected, the first power incoming line switch 1DL will trip, and the fifth power incoming line switch 11DL will close.

[0055] Optionally, with the first feeder switch in the closed position, the method further includes:

[0056] S410. If the first power input switch is closed, the fifth power input switch is open, and the voltage output from the common bus of the standby transformer is qualified, a switching signal is detected, and the fifth power input switch is controlled to close and the first power input switch is opened.

[0057] Specifically, see Figure 1 When the first feeder switch 10DL is in the closed position, and the first power input switch 1DL is detected to be closed, the fifth power input switch 11DL is detected to be open, and the backup power supply voltage of the backup transformer common section bus is qualified, if a switching signal is detected, the fifth power input switch 11DL will be closed, and the first power input switch 1DL will be tripped. It should be noted that the switching signal can be a manual switching signal.

[0058] Optionally, with the first feeder switch in the closed position, the method further includes:

[0059] S420. If the first power input switch is open, the fifth power input switch is closed, and the voltage output by the first high-voltage plant transformer is qualified, a switching signal is detected, and the first power input switch is controlled to close and the fifth power input switch is open.

[0060] Specifically, see Figure 1 When the first feeder switch 10DL is in the closed position, and the fifth power input switch 11DL is detected to be closed, the first power input switch 1DL is detected to be open, and the operating power supply voltage of the first high-voltage plant service transformer is qualified, if a switching signal is detected, the first power input switch 1DL will be closed and the fifth power input switch 11DL will be tripped. It should be noted that the switching signal can be a manual switching signal.

[0061] Optionally, the method further includes:

[0062] S510. If the first power supply incoming switch is closed and the first high-voltage plant service transformer is energized, the fifth power supply incoming switch is open, the first feeder switch is closed and the standby transformer common section busbar is energized, and the sixth power supply incoming switch is open.

[0063] S520. Control the fifth power input switch to be closed and the first feeder switch to be open, so that the first section of working busbar can be used as a backup for the third section of working busbar.

[0064] Specifically, see Figure 1In the event of an upcoming overhaul of the high-voltage standby transformer or the standby transformer common section, the first working busbar section 1A serves as a backup for the third working busbar section 2A. The first power supply incoming switch 1DL is closed and the working switch is energized. The working power supply of the first high-voltage station service transformer supplies power to the busbar through the working branch. The fifth power supply incoming switch 11DL is open, the first feeder switch 10DL is closed and the low-voltage side of the high-voltage standby transformer is energized, and the sixth power supply incoming switch 12DL is open. The special input "Close the fifth power supply incoming switch 11DL, trip the first feeder switch 10DL" is activated. At this time, the DCS / local start fast switch requires closing the fifth power supply incoming switch 11DL and tripping the first feeder switch 10DL. During this time, the first working busbar section 1A serves as a backup for the third working busbar section 2A. After the switchover is complete: 1DL is closed and the working incoming line is energized, 11DL is closed, and 10DL and 12DL are open. After confirming that 10DL is open, 10DL is moved to the test position, and the control power supply to 10DL is disconnected.

[0065] Optionally, the method further includes:

[0066] S610. If the first power supply incoming switch is closed and the first high-voltage plant service transformer is energized, the fifth power supply incoming switch is closed, the first feeder switch is open and the standby transformer common section busbar is energized, and the sixth power supply incoming switch is open.

[0067] S620. Control the first feeder switch to be closed and the fifth power input switch to be open, so that the spare transformer common section busbar can be used as a spare for the third working section busbar.

[0068] Specifically, see Figure 1 With the first working busbar section 1A serving as a backup for the third working busbar section 2A, and the high-voltage standby transformer or standby transformer common section maintenance completed, the standby transformer common section busbar is restored as a backup for the third working busbar section 2A. The first power supply incoming switch 1DL is closed and the working incoming line is energized; the working power supply supplies power to the first working busbar section through the working branch. The fifth power supply incoming switch 11DL is closed, the first feeder switch 10DL is open and the standby transformer common section busbar is energized, and the sixth power supply incoming switch 12DL is open. The "Close 10DL, Trip 11DL" special input is activated. At this time, the DCS / local start fast-switching device needs to close the first feeder switch 10DL and trip the fifth power supply incoming switch 11DL. At this point, the standby transformer common section busbar serves as a backup for the third working busbar section 2A.

[0069] Optionally, the method further includes:

[0070] S710. If the first power supply incoming switch is closed and the first high-voltage plant service transformer is energized, the fifth power supply incoming switch is open, the first feeder switch is closed and the standby transformer common section busbar is energized, and the sixth power supply incoming switch is closed.

[0071] S720: Control the fifth power input switch to be closed and the first feeder switch to be open, so that the first working busbar supplies power to the shutdown load of the third working busbar.

[0072] Specifically, see Figure 1 When Unit 2 is shut down, the first working bus section 1A supplies power to the shutdown load of the third working bus section 2A. The first power supply incoming switch 1DL is closed and the working incoming line is energized. The working power supply supplies power to the first working bus section through the working branch. The fifth power supply incoming switch 11DL is open, the first feeder switch 10DL is closed and the standby transformer common section bus is energized, and the sixth power supply incoming switch 12DL is closed. The "Close 11DL, Trip 10DL" special input is activated. At this time, the DCS / local start fast switch requires closing the fifth power supply incoming switch 11DL and tripping the first feeder switch 10DL. At this point, the first working bus section 1A supplies power to the shutdown load of the third working bus section 2A. After the switchover is completed: the first power supply incoming switch 1DL is closed and the working incoming line is energized; the fifth power supply incoming switch 11DL and the sixth power supply incoming switch 12DL are closed; and the first feeder switch 10DL is open.

[0073] The control methods for the second and fourth working busbars can be deduced by analogy. (See also...) Figure 1 For example, in the above control method, “first power input switch 1DL” can be changed to “second power input switch 2DL”, “fifth power input switch 11DL” can be changed to “seventh power input switch 21DL”, “first feeder switch 10DL” can be changed to “second feeder switch 20DL”, “sixth power input switch 12DL” can be changed to “eighth power input switch 22DL”, and “section A” can be changed to “section B”.

[0074] Implementing the embodiments of the present invention has the following beneficial effects: In this embodiment, if a fault signal occurs in the first working bus or the first power input switch, the first power input switch and the fifth power input switch are controlled to enable the standby transformer common section bus to provide backup power to the first working bus. If the high-voltage standby transformer or the standby transformer common section is under maintenance, the first feeder switch and the fifth power input switch are controlled to enable the first working bus to provide backup power to the third working bus. If the second unit generator system shuts down, the first feeder switch and the fifth power input switch are controlled to enable the first working bus to supply power to the shutdown load of the third working bus. This achieves flexible control of the high-voltage standby transformer and the high-voltage plant service transformer and the plant service interconnection in the three-power switching system for plant power, improving the safety and economy of the system.

[0075] See Figure 3 This invention provides a control system for a three-power supply switching system for plant power, comprising:

[0076] The first module is used to control the first power input switch and the first feeder switch to be closed, and to control the fifth power input switch to be open, so that the first high-voltage plant service transformer supplies power to the first section of working bus, and the switching device enters the fault monitoring state.

[0077] The second module is used to control the first power input switch to open and the fifth power input switch to close if a fault signal is detected in the first working bus, the first power input switch is closed, the fifth power input switch is open, and the voltage output of the standby transformer common bus is qualified.

[0078] The third module is used to control the first power input switch to open and the fifth power input switch to close if a fault signal is detected in the first power input switch, the first power input switch is closed, the fifth power input switch is open, and the voltage output from the common bus of the standby transformer is qualified.

[0079] It is evident that the content of the above method embodiments is applicable to this system embodiment. The specific functions implemented in this system embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0080] See Figure 4 This invention provides a control device for a three-power supply switching system for plant power, comprising:

[0081] At least one processor;

[0082] At least one memory for storing at least one program;

[0083] When the at least one program is executed by the at least one processor, the at least one processor performs the method described above.

[0084] The memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. The memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory may optionally include remote memory located remotely relative to the processor, which can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0085] It is evident that the content of the above method embodiments is applicable to the present device embodiments. The specific functions implemented in the present device embodiments are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0086] Furthermore, this application also discloses a computer program product or computer program stored in a computer-readable storage medium. A processor of a computer device can read the computer program from the computer-readable storage medium, and the processor executes the computer program, causing the computer device to perform the described method. Similarly, the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0087] This invention also provides a computer-readable storage medium storing a processor-executable program that, when executed by a processor, implements the above-described method.

[0088] It is understood that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0089] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A control method for a three-power supply switching system for plant auxiliary power, characterized in that, The switching system includes two unit generator systems, four switching devices, one high-voltage standby transformer, and one common busbar section for the standby transformer. Each unit generator system includes one high-voltage station service transformer and two working busbar sections. The first high-voltage station service transformer is connected to the first working busbar section via a first power input switch, the first high-voltage station service transformer is connected to the second working busbar section via a second power input switch, the second high-voltage station service transformer is connected to the third working busbar section via a third power input switch, and the second high-voltage station service transformer is connected to the fourth working busbar section via a fourth power input switch. The low-voltage side of the high-voltage standby transformer is connected to the standby transformer via a standby input switch. A common busbar is provided, and the standby common busbar is connected to the first working busbar via a first feeder switch and a fifth power input switch. The standby common busbar is also connected to the third working busbar via a first feeder switch and a sixth power input switch. The standby common busbar is connected to the second working busbar via a second feeder switch and a seventh power input switch. The standby common busbar is also connected to the fourth working busbar via a second feeder switch and an eighth power input switch. All working buses, the standby common busbar, all power input switches, and all feeder switches are connected to any one of the four switching devices. The control method includes: Control the first power input switch and the first feeder switch to be closed, and control the fifth power input switch to be open, so that the first high-voltage plant service transformer supplies power to the first section of working bus, and the switching device enters the fault monitoring state. If the first power supply incoming switch is closed and the first high-voltage plant service transformer is energized, the fifth power supply incoming switch is open, the first feeder switch is closed and the standby transformer common section busbar is energized, and the sixth power supply incoming switch is open; Control the fifth power input switch to be closed and the first feeder switch to be open, so that the first section of working busbar can be used as a backup for the third section of working busbar; or, control the first feeder switch to be closed and the fifth power input switch to be open, so that the backup transformer public section busbar can be used as a backup for the third section of working busbar.

2. The control method according to claim 1, characterized in that, The method further includes: If a fault signal is detected in the first working busbar, the first power input switch is closed, the fifth power input switch is open, and the voltage output from the standby transformer common busbar is qualified, the first power input switch is controlled to be open and the fifth power input switch is controlled to be closed. If a fault signal is detected in the first power input switch, the first power input switch is closed, the fifth power input switch is open, and the voltage of the standby transformer common section bus is qualified, the first power input switch is controlled to open and the fifth power input switch is controlled to close.

3. The control method according to claim 2, characterized in that, The method further includes: If the first power input switch is closed, the fifth power input switch is open, and the voltage output from the common bus of the standby transformer is qualified, a switching signal is detected, and the fifth power input switch is controlled to close and the first power input switch is opened.

4. The control method according to claim 2, characterized in that, The method further includes: If the first power input switch is open, the fifth power input switch is closed, and the voltage output by the first high-voltage plant transformer is qualified, a switching signal is detected, and the first power input switch is controlled to close and the fifth power input switch is open.

5. The control method according to claim 2, characterized in that, The method further includes: If the first power supply incoming switch is closed and the first high-voltage plant service transformer is energized, the fifth power supply incoming switch is open, the first feeder switch is closed and the standby transformer common section busbar is energized, and the sixth power supply incoming switch is closed. Control the fifth power input switch to be closed and the first feeder switch to be open, so that the first working busbar supplies power to the shutdown load of the third working busbar.

6. A control system for a three-power supply switching system for plant auxiliary power, characterized in that, Used to implement the control method as described in any one of claims 1-5.

7. A control device for a three-power supply switching system for plant power, characterized in that, include: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor performs the method as described in any one of claims 1-5.

8. A computer-readable storage medium storing a processor-executable program, characterized in that, The processor-executable program, when executed by the processor, is used to perform the method as described in any one of claims 1-5.

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