Power plant starting and standby transformer gateway metering voltage logic switching method and system
By constructing a closed-loop system for real-time data acquisition and intelligent logic judgment, the problem of incorrect electricity metering by the standby transformer metering device under complex operating conditions has been solved, ensuring the accuracy and uniqueness of electricity metering, reducing manual intervention and operating costs, and improving the automation level and operation and maintenance efficiency of the power plant.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-23
- Publication Date
- 2026-03-27
AI Technical Summary
Under complex operating conditions where multiple generator sets operate in parallel, existing technologies cannot accurately determine the self-generation and self-consumption status of standby transformer metering devices, leading to distorted electricity metering. Furthermore, the lack of effective testing and verification methods poses risks to logical correctness and reliability.
A closed-loop system integrating real-time data acquisition, intelligent logic judgment, automatic control execution, and high-fidelity simulation testing is constructed. The system collects power grid status signals through a data communication gateway, uses a precise combinational logic algorithm to determine the power plant's operating status, and integrates an offline simulation testing system to verify the correctness of the logic.
It achieves accurate and unique metering of standby power in complex operating modes, reduces manual intervention and operating costs, improves operational reliability and ease of maintenance, and has significant technological advancement and application promotion value.
Smart Images
Figure CN121749489A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power system automation technology, and in particular to a method and system for switching the metering voltage logic at the start-up and standby transformer gates of a power plant. Background Technology
[0002] With the continuous expansion of the power system and the increasing complexity of its operation, the accuracy of electricity metering within thermal power plants, especially the settlement of electricity consumption at the grid connection, has become crucial. Grid connection metering serves as the basis for electricity trade settlement between power plants and the power grid, and its accuracy directly affects the economic interests of both parties. In power plant operation, there exists a condition known as self-consumption, where the power plant generates electricity to supply its own internal equipment without receiving power from the grid. According to the national metrology regulations, "Minutes of the Review Meeting on Grid Connection Electricity Metering Devices for Coal-fired Power Generating Units and Equivalent Capacity Substitution Projects," under this condition, the grid connection metering point of the starting or standby transformer (hereinafter referred to as "starting and standby transformer") used to receive power from the grid should not be metered to avoid artificially inflating the amount of electricity supplied to the grid.
[0003] In existing technologies, many power plants employ a simple "two-out-of-three" voltage loop switching design for their power metering systems for operating or standby transformers. While this design may be effective for simple operating conditions, its limitations become apparent in complex scenarios involving multiple generator units operating in parallel. For example, when some units are generating electricity while others are shut down or undergoing maintenance, the plant's power grid structure changes frequently. The simple "two-out-of-three" logic cannot accurately determine whether the power plant is operating for self-consumption or requires grid connection (i.e., self-generated electricity cannot be used for self-consumption). This can lead to metering devices on operating or standby transformers continuing to operate when metering should stop, or being incorrectly disconnected when metering is needed, resulting in distorted electricity metering and disputes over electricity billing.
[0004] Furthermore, due to the high reliability and continuity requirements of power production, newly built or upgraded metering and control systems cannot undergo sufficient testing in a real power grid, covering all possible operating conditions. The lack of a safe and reliable testing and verification method poses potential risks to the system's logical correctness and operational reliability, creating hidden dangers for future commissioning.
[0005] Therefore, there is an urgent need in this field for a power plant start-up and standby transformer switching method and system that can adapt to complex operating modes, accurately determine self-generation and self-consumption status, and have complete simulation testing capabilities, in order to solve the problems of inaccurate metering, insufficient reliability and difficulty in testing and verification of existing technologies. Summary of the Invention
[0006] In view of this, in order to overcome the shortcomings of the prior art, the present invention provides a method and system for switching the metering voltage logic at the power plant start-up and standby transformer. By constructing a closed-loop system integrating real-time data acquisition, intelligent logic judgment, automatic control execution and high-fidelity simulation testing, the real-time status of the power grid is collected through a data communication gateway, and the switching of the metering voltage loop is controlled by the built-in precision combinational logic algorithm. In addition, an offline simulation testing system is uniquely integrated to verify the correctness of the main logic.
[0007] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions: In a first aspect, the present invention provides a method for switching the metering voltage logic at the start-up / standby transformer gate in a power plant, comprising the following steps: The data communication gateway collects in real time the switching status signals of gas-insulated switchgear, disconnector position signals, and generator operating power signals of the power plant grid. Based on the preset self-consumption combination logic rules, the collected switch status signals, disconnector position signals and operating power signals are analyzed to determine whether the current operating state of the power plant is a self-consumption state or a self-consumption but not self-consumption state. When the system is determined to be in a self-generated and self-used state, a control command is output to the contactor of the metering voltage circuit of the standby transformer equipment to disconnect the voltage circuit of the switch meter and cut off the voltage input of the switch meter. When the system is determined to be in a self-generated and self-used state, a control command is output to close the contactor, close the voltage circuit of the switch meter, and restore metering.
[0008] As a further aspect of the present invention, when determining whether the power plant is currently in a self-generation and self-consumption state or a self-generation and self-consumption inability state, the self-generation and self-consumption combination logic rule is as follows: when any generator unit in the power plant is in a power generation state and is connected to the 220kV busbar through the outlet circuit breaker, it is determined that the entire plant is in a self-generation and self-consumption state.
[0009] As a further aspect of the present invention, when the operating power signal of any generator unit in the power plant is greater than zero, the auxiliary contact signal of the corresponding 220kV outlet circuit breaker is in the closed position, which means that the entire plant meets the self-generation and self-consumption conditions.
[0010] As a further aspect of the present invention, when determining the current operating status of the power plant, the determination is performed independently and in parallel for each standby transformer, and the status signals of all bus disconnectors and switches connected to the standby transformer are judged. The metering voltage circuit is only allowed to close when electrical energy flows from the grid to the plant's service power through the standby transformer.
[0011] As a further aspect of the present invention, when determining whether the power plant is currently in a self-consumption state or a self-consumption inability state, the determination is performed separately for each standby transformer. The determination logic is based on the state combination of all bus disconnectors and switches related to the electrical connection of the standby transformer. The self-consumption combination logic is pre-set in the system in the form of a truth table or logic diagram.
[0012] As a further aspect of the present invention, the power plant start-up / standby transformer switching method for metering voltage logic further includes: In an offline environment, the simulation system generates switch status signals, disconnector position signals, and operating power signals under various operating conditions, and determines whether the power plant is currently in a self-consumption state or a self-consumption but not self-consumption state based on the simulated signals. Observe and record the system's judgment results and control commands driven by the simulated signals to verify the accuracy and reliability of the self-generated combinational logic rules.
[0013] As a further aspect of the present invention, the simulation system performs simulation testing through a graphical human-machine interface. The graphical human-machine interface simulates the main electrical wiring diagram of a power plant, allowing users to manually operate it to change the state of virtual switches and disconnectors, thereby dynamically generating the simulated signals.
[0014] As a further aspect of the present invention, when determining the current operating status of the power plant, a set power determination threshold is also included. When the operating power signal value of the generator unit is greater than the power determination threshold, it is determined that the generator unit is in the power generation state.
[0015] As a further aspect of the present invention, when the output control command changes the contactor state from closed to open or from open to closed, a critical switch state signal verification is triggered to determine whether the critical switch state signal remains stable within a set delay after the command is issued. If a jump occurs, the command is immediately revoked and an alarm is issued to prevent malfunctions caused by signal jitter.
[0016] Secondly, the present invention also provides a power plant start-up / standby transformer switching system for metering voltage logic, comprising: The data acquisition module is configured to acquire in real time the switching status signals of gas-insulated switchgear, disconnector position signals, and generator operating power signals of the power plant grid through the data communication gateway. The logic processing module is communicatively connected to the data acquisition module and is configured to analyze the received signals based on preset self-consumption combination logic rules to determine whether the power plant's current operating state is a self-consumption state or a self-consumption inability state. The control execution module is connected to the logic processing module and is configured to receive the judgment result; when the judgment is that it is in a self-generated and self-used state, it outputs a control command to disconnect the metering voltage circuit contactor of the standby transformer; when the judgment is that it is in a self-generated and self-used state, it outputs a control command to close the contactor.
[0017] As a further aspect of the present invention, the preset self-generation and self-consumption combination logic rule in the logic processing module is as follows: when the operating power signal of any generator unit in the power plant is greater than zero, and the auxiliary contact signal of its corresponding 220kV outlet circuit breaker is in the closed position, it is determined that the entire plant is in a self-generation and self-consumption state.
[0018] As a further aspect of the present invention, the logic processing module is configured to perform state determination independently and in parallel for each standby transformer; its determination logic is based on the state combination of all bus disconnectors and switches related to the electrical connection of the standby transformer, to ensure that the metering voltage loop is allowed to close only when electrical energy flows from the grid to the plant's service power through the standby transformer.
[0019] As a further aspect of the present invention, the self-generated and self-used combinational logic rules are pre-set in the logic processing module in the form of a truth table or a logic diagram; the logic diagram specifically defines the control strategy of the metering circuit under different combinations of disconnector states.
[0020] As a further aspect of the present invention, the power plant start-up / standby transformer switching system for metering voltage logic further includes: The simulation testing module is switchably connected to the logic processing module; The simulation test module is configured to simulate and generate switch status signals, disconnector position signals, and operating power signals under various operating conditions in an offline environment, in order to verify the accuracy and reliability of the self-generated and self-used combinational logic rules.
[0021] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: The present invention relates to a method and system for switching the metering voltage logic at the power plant's standby transformer switching point. Based on the self-generation and self-consumption combination logic judgment of the power grid topology, it solves the problem of miscalculation and omission of standby transformer power volume under the condition of multiple units operating in parallel. By analyzing the electrical connection relationship and generation status of the entire plant in real time, metering is only performed when the power is confirmed to flow from the grid to the plant's consumption through the standby transformer, ensuring the uniqueness and accuracy of the switching point power volume data. The present invention uses a clear logic diagram and truth table pre-installed in the system as the judgment logic, realizing the full automation of the standby transformer metering switching process, reducing manual intervention, lowering operating costs and the risk of human error. It brings multi-dimensional and substantial improvements in metering accuracy, operational reliability, maintenance convenience and compliance, and has significant technological advancement, practicality and wide application and promotion value.
[0022] These or other aspects of the invention will become more apparent from the following description of embodiments. It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. In the drawings: Figure 1 This is a flowchart of a power plant start-up and standby transformer switching method for metering voltage logic switching according to the present invention.
[0024] Figure 2 This is a structural block diagram of a power plant start-up and standby transformer switching system for metering logic switching according to the present invention.
[0025] Figure 3 This is an architecture diagram of a power plant start-up and standby transformer switching system for metering logic switching according to the present invention. Detailed Implementation
[0026] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.
[0027] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.
[0028] See Figure 1 As shown in the figure, an embodiment of this application also provides a method for switching the metering voltage logic at the start-up / standby transformer in a power plant, including the following steps: Step S10: Real-time acquisition of switch status signals, disconnector position signals, and generator operating power signals of gas-insulated switchgear in the power plant grid through the data communication gateway.
[0029] In this step, three types of key signals are collected from the power plant monitoring system or smart devices via a data communication gateway and protocol converter. For example: The switch status signal is the "open / closed" position of the 220kV GIS circuit breaker (such as 22A, 22B, 22C, 22D, 22E) (closed position = 1, open position = 0). Disconnector position signal: The "open / closed" position of the disconnectors (such as 221A, 221B, 221C, 221D) associated with the bus connection; Operating power signal: Active power value of each generator set from #1 to #5 (unit: MW).
[0030] The system can read in real time: #1 unit power P1=300MW (>0), its output circuit breaker 22A is in the "closed" position (1); #3 unit power P3=0MW, its output circuit breaker 22C is in the "open" position (0); disconnectors 221B and 221C are in the "closed" position, and 221D is in the "open" position.
[0031] Step S20: Based on the preset self-consumption combination logic rules, analyze the collected switch status signals, disconnector position signals and operating power signals to determine whether the power plant's current operating state is a self-consumption state or a self-consumption but not self-consumption state.
[0032] In this step, when determining whether the power plant is currently in a self-consumption state or a self-consumption inability state, the self-consumption combination logic rule is: when any generator unit in the power plant is generating electricity and connected to the 220kV busbar through the outlet circuit breaker, it is determined that the entire plant is in a self-consumption state.
[0033] In this embodiment, when the operating power signal of any generator unit in the power plant is greater than zero, the auxiliary contact signal of the corresponding 220kV outlet circuit breaker is in the closed position, which means that the whole plant meets the self-generation and self-consumption conditions.
[0034] In this embodiment, when determining the current operating status of the power plant, the determination is performed independently and in parallel for each standby transformer, and the status signals of all bus disconnectors and switches connected to the standby transformer are judged. The metering voltage circuit is only allowed to close when electrical energy flows from the grid to the plant's service power through the standby transformer.
[0035] When determining whether the power plant is currently in a self-consumption state or a self-consumption inability state, the determination is performed separately for each standby transformer. The determination logic is based on the state combination of all bus disconnectors and switches related to the electrical connection of the standby transformer. The self-consumption combination logic is pre-set in the system in the form of a truth table or logic diagram.
[0036] In this embodiment, when determining the current operating status of the power plant, a set power determination threshold is also included. When the operating power signal value of the generator unit is greater than the power determination threshold, it is determined that the generator unit is in the power generation state.
[0037] When determining whether a power plant's current operating status is self-consumption or not self-consumption, a quick determination can be made based on the global generation status. This involves checking if any unit is generating power and connected to the system. The condition is: for any unit i, P_i > P_set (e.g., P_set = 1MW) and its output circuit breaker is in the "closed" position. If any unit meets this condition, the global flag Plant_Generating is set to 1 (True). For example: Unit #1 has P1 = 300MW > 1MW, and 22A = 1, therefore, the entire plant's Plant_Generating is immediately determined to be 1 (potential for self-consumption).
[0038] The system can also precisely determine whether electrical energy must flow through a specific standby transformer. Each standby transformer (#01, #02, #03) operates its own set of combinational logic based on its electrical connections. This logic is pre-defined in the form of a truth table or logic diagram. For example, taking standby transformer #03 as an example, Scenario A (metering should be disconnected): Plant_Generating=1, and disconnectors 221B and 221C are closed, while 221D is open. This wiring indicates that the bus connected to standby transformer #03 can be powered by operating units such as #1 and #2 through 221B / C, which is for self-consumption and should not be metered. The system determines this as "self-consumption" and outputs a command to disconnect the #03 metering voltage circuit. Scenario B (metering should be activated): Plant_Generating=1, but disconnectors 221B and 221C are open, while 221D is closed. This wiring indicates that the busbar connected to the #03 standby transformer is isolated, and its load must receive power from the grid through the #03 standby transformer. The system determines this as "self-generated power cannot be used by itself" and outputs a command to close the #03 metering voltage circuit.
[0039] Step S30: When the self-generation and self-use state is determined, output control command to the metering voltage circuit contactor of the standby transformer equipment to disconnect the voltage circuit of the switch meter and cut off the voltage input of the switch meter; when the self-generation and self-use state is determined, output control command to close the contactor to close the voltage circuit of the switch meter and restore metering.
[0040] In this step, when the output control command changes the contactor state from closed to open or from open to closed, the critical switch state signal verification is triggered to determine whether the critical switch state signal remains stable within the set delay after the command is issued. If a jump occurs, the command is immediately canceled and an alarm is issued to prevent malfunctions caused by signal jitter.
[0041] In this embodiment, a delay check is added to prevent malfunctions caused by signal jitter. After the command is issued, a delay T_d (e.g., 500ms) is initiated, during which the status of critical signals is continuously checked. For example: the system determines that the #01 standby transformer metering circuit needs to be disconnected. Within 500ms after issuing the disconnect command, if the system detects that the status of the critical disconnector 221A suddenly jumps from "1" to "0" (possibly due to signal interference), the disconnect command is immediately revoked, and the alarm interface is triggered to record this anomaly, preventing a false disconnection.
[0042] In one embodiment, the power plant standby transformer switching method for metering voltage logic further includes: In an offline environment, a simulation system is used to generate switch status signals, disconnector position signals, and operating power signals under various operating conditions. The simulated signals are used to determine whether the power plant is currently in a self-consumption state or a state where it cannot be self-consumed. The system's determination results and control commands driven by the simulated signals are observed and recorded to verify the accuracy and reliability of the self-consumption combination logic rules.
[0043] The simulation system performs simulation tests through a graphical human-machine interface (HMI). The HMI simulates the main electrical wiring diagram of a power plant, allowing users to manually operate the virtual switches and disconnectors to change their states, thereby dynamically generating the simulated signals.
[0044] Before system commissioning or after logic modifications, conduct full-condition safety testing. Disconnect the communication lines connecting to the real equipment and switch to the simulation testing system. For example, maintenance personnel need to test the complex operating condition of "only Unit #4 is operating, and the standby transformer #02 is powered on." They operate on the graphical interface of the simulation system: click to close the circuit breaker 22D at the outgoing circuit of Unit #4, close disconnectors 221A and 221D, disconnect other disconnectors, and set the power of Unit #4 to 200MW. The simulation system sends the simulated signals to the core logic processing module. After the module makes a judgment, the maintenance personnel can see the judgment result as "Metering of the standby transformer #02 is activated" on the quick diagnostic interface, and the triggered logic condition is "Category A, Subcategory 1," consistent with expectations, thus verifying the correctness of the logic.
[0045] The power plant start-up and standby transformer switching voltage logic method of this invention solves the problem of inaccurate power metering of start-up and standby transformers under complex operating conditions, ensures the fairness, impartiality and compliance of power metering, and improves the automation level and operation and maintenance efficiency of power plants. Its innovation is prominent, its practicality is strong, and it has extremely high promotion value.
[0046] In some embodiments, see Figure 2 and Figure 3As shown, this embodiment of the invention provides a power plant standby transformer switching voltage logic switching system. This system is used to execute the steps of the aforementioned power plant standby transformer switching voltage logic switching method. The power plant standby transformer switching voltage logic switching system includes: The data acquisition module is configured to acquire in real time the switching status signals of gas-insulated switchgear, disconnector position signals, and generator operating power signals of the power plant grid through the data communication gateway. The logic processing module is communicatively connected to the data acquisition module and is configured to analyze the received signals based on preset self-consumption combination logic rules to determine whether the power plant's current operating state is a self-consumption state or a self-consumption inability state. The control execution module is connected to the logic processing module and is configured to receive the judgment result; when the judgment is that it is in a self-generated and self-used state, it outputs a control command to disconnect the metering voltage circuit contactor of the standby transformer; when the judgment is that it is in a self-generated and self-used state, it outputs a control command to close the contactor.
[0047] In this embodiment, the preset self-generation and self-consumption combination logic rule in the logic processing module is as follows: when the operating power signal of any generator unit in the power plant is greater than zero, and the auxiliary contact signal of its corresponding 220kV outlet circuit breaker is in the closed position, it is determined that the entire plant is in a self-generation and self-consumption state.
[0048] In this embodiment, the logic processing module is configured to perform state determination independently and in parallel for each standby transformer; its determination logic is based on the state combination of all bus disconnectors and switches related to the electrical connection of the standby transformer, so as to ensure that the metering voltage loop is allowed to close only when electrical energy flows from the grid to the plant power through the standby transformer.
[0049] In this embodiment, the self-generated and self-used combination logic rules are pre-set in the logic processing module in the form of a truth table or a logic diagram; the logic diagram specifically defines the control strategy of the metering circuit under different combinations of disconnector states.
[0050] In this embodiment, the power plant start-up / standby transformer switching system for metering voltage logic further includes: The simulation testing module is switchably connected to the logic processing module; The simulation test module is configured to simulate and generate switch status signals, disconnector position signals, and operating power signals under various operating conditions in an offline environment, in order to verify the accuracy and reliability of the self-generated and self-used combinational logic rules.
[0051] The present invention relates to a method and system for switching the metering voltage logic at the power plant's standby transformer switching point. Based on the self-generation and self-consumption combination logic judgment of the power grid topology, it solves the problem of miscalculation and omission of standby transformer power volume under the condition of multiple units operating in parallel. By analyzing the electrical connection relationship and generation status of the entire plant in real time, metering is only performed when the power is confirmed to flow from the grid to the plant's consumption through the standby transformer, ensuring the uniqueness and accuracy of the switching point power volume data. The present invention uses a clear logic diagram and truth table pre-installed in the system as the judgment logic, realizing the full automation of the standby transformer metering switching process, reducing manual intervention, lowering operating costs and the risk of human error. It brings multi-dimensional and substantial improvements in metering accuracy, operational reliability, maintenance convenience and compliance, and has significant technological advancement, practicality and wide application and promotion value.
[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for switching the metering voltage logic at the start-up / standby transformer gate in a power plant, characterized in that, Includes the following steps: The data communication gateway collects in real time the switching status signals of gas-insulated switchgear, disconnector position signals, and generator operating power signals of the power plant grid. Based on the preset self-consumption combination logic rules, the collected switch status signals, disconnector position signals and operating power signals are analyzed to determine whether the current operating state of the power plant is a self-consumption state or a self-consumption but not self-consumption state. When the system is determined to be in a self-generated and self-used state, a control command is output to the contactor of the metering voltage circuit of the standby transformer equipment to disconnect the voltage circuit of the switch meter and cut off the voltage input of the switch meter. When the system is determined to be in a self-generated and self-used state, a control command is output to close the contactor, close the voltage circuit of the switch meter, and restore metering.
2. The power plant start-up / standby transformer switching method for metering voltage logic as described in claim 1, characterized in that, When determining whether a power plant is currently in a self-consumption state or a state where it cannot be self-consumed, the self-consumption combination logic rule is as follows: when any generator unit in the power plant is generating electricity and connected to the 220kV busbar through the outlet circuit breaker, it is determined that the entire plant is in a self-consumption state.
3. The power plant start-up / standby transformer switching method for metering voltage logic as described in claim 2, characterized in that, When the operating power signal of any generator unit in the power plant is greater than zero, and the auxiliary contact signal of the corresponding 220kV outgoing circuit breaker is in the closed position, it is determined that the entire plant meets the self-generation and self-consumption conditions.
4. The power plant start-up / standby transformer switching method for metering voltage logic as described in claim 3, characterized in that, When determining the current operating status of the power plant, each standby transformer is operated independently and in parallel. The status signals of all bus disconnectors and switches connected to the standby transformer are also checked. The metering voltage circuit is only allowed to close when electrical energy flows from the grid to the plant's service power through the standby transformer.
5. The power plant start-up / standby transformer switching method for metering voltage logic as described in claim 3, characterized in that, When determining whether the power plant is currently in a self-consumption state or a self-consumption inability state, the determination is performed separately for each standby transformer. The determination logic is based on the state combination of all bus disconnectors and switches related to the electrical connection of the standby transformer. The self-consumption combination logic is pre-set in the system in the form of a truth table or logic diagram.
6. The power plant start-up / standby transformer switching method for metering voltage logic as described in claim 1, characterized in that, The power plant start-up and standby transformer switching method for metering voltage logic also includes: in an offline environment, simulating and generating switch status signals, disconnector position signals and operating power signals under various operating conditions through a simulation system, and determining whether the power plant is currently in a self-generated and self-consumed state or a self-generated and non-self-consumed state based on the simulated signals.
7. The power plant start-up / standby transformer switching method for metering voltage logic as described in claim 6, characterized in that, The simulation system performs simulation tests through a graphical human-machine interface. The graphical human-machine interface simulates the main electrical wiring diagram of a power plant, allowing users to manually operate it to change the state of virtual switches and disconnectors, and dynamically generate the simulated signals.
8. The power plant start-up / standby transformer switching method for metering voltage logic as described in claim 4, characterized in that, When determining the current operating status of a power plant, a set power determination threshold is also included. When the operating power signal value of the generator unit is greater than the power determination threshold, it is determined that the generator unit is in power generation status.
9. The power plant start-up / standby transformer switching method for metering voltage logic as described in claim 1, characterized in that, When the output control command changes the contactor state from closed to open or from open to closed, the critical switch state signal verification is triggered to determine whether the critical switch state signal remains stable within a set delay after the command is issued. If a change occurs, the command is immediately revoked and an alarm is issued.
10. A power plant start-up / standby transformer switching system for metering voltage logic, characterized in that, For performing the steps of the power plant standby transformer switching metering voltage logic switching method as described in any one of claims 1-9, the power plant standby transformer switching metering voltage logic switching system includes: The data acquisition module is configured to acquire in real time the switching status signals of gas-insulated switchgear, disconnector position signals, and generator operating power signals of the power plant grid through the data communication gateway. The logic processing module is communicatively connected to the data acquisition module and is configured to analyze the received signals based on preset self-consumption combination logic rules to determine whether the power plant's current operating state is a self-consumption state or a self-consumption inability state. The control execution module is connected to the logic processing module and is configured to receive the judgment result; when the judgment is that it is in a self-generated and self-used state, it outputs a control command to disconnect the metering voltage circuit contactor of the standby transformer; when the judgment is that it is in a self-generated and self-used state, it outputs a control command to close the contactor.