Method for judging hot standby state of voltage output equipment based on induced voltage
By combining induced voltage and auxiliary contact signals, accurate judgment of the hot standby status of 500kV equipment in the power system is achieved, which solves the safety risks of abnormal equipment status transition and improves the accuracy of judgment and operation and maintenance efficiency.
Patent Information
- Application Number
- CN202511335342.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-18
- Publication Date
- 2025-11-18
AI Technical Summary
During the maintenance of 500kV equipment in the power system, the safety risks caused by abnormal state transitions of grounding switches, isolating switches, and circuit breakers are difficult to observe and judge directly. This may lead to serious consequences such as non-full-phase operation and closing with the grounding switch on, posing an extremely high risk to the safe and stable operation of the power system.
By using the induced voltage method, the voltage generated when the AC 500kV switch is opened is combined with the auxiliary contact position signal to measure and compare the voltage transformer, and determine whether the grounding switch, isolating switch and the three phases of the switch are normal, so as to ensure accurate judgment of equipment status.
It improves the accuracy of equipment status assessment, reduces costs, shortens maintenance preparation time, and eliminates the risk of serious accidents such as non-full-phase operation and closing with the grounding switch.
Smart Images
Figure CN120971945A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of power systems, in particular to a method for judging the hot standby state of a voltage output device based on induced voltage. BACKGROUND
[0002] During the maintenance process of a 500kV device in a power system, the switch is often disconnected, the isolation switch is pulled open, and the grounding switch is closed to achieve grounding, thereby providing safe conditions for maintenance work. After the maintenance is completed, before the 500kV device is powered on to resume operation, the corresponding grounding switch is pulled open, the isolation switch is closed, and the 500kV switch is converted to a hot standby state, as shown in FIG. 1, i.e., the switch is disconnected, the grounding switch on both sides is pulled open, and the isolation switch is closed. In this process, it is not possible to directly and actually observe whether the state conversion of the grounding switch, the isolation switch, and the switch is normal, and it can only be judged by the action of the corresponding device auxiliary contact. Since the grounding switch transmission mechanism, connecting rod, and other components have a certain probability of abnormal function, the grounding switch auxiliary contact may act while the three-phase body is not fully disconnected. At this time, the power-on may cause the grounding switch to close or the three-phase to run inconsistently, which may cause extremely serious consequences and pose a high risk to the safe and stable operation of the power system. If the three-phase isolation switch is not fully closed in the hot standby state, the 500kV device will run in a non-full-phase state when it is converted to the running state, which will result in a large unbalanced current and a high risk of operation. If the switch actually exists in an abnormal state of non-full-phase closing while displaying disconnection in the hot standby state, it is also a major risk that needs to be avoided. Figure 5 SUMMARY
[0003] To solve the above problems, the present application provides a method for judging the hot standby state of a voltage output device based on induced voltage. By utilizing the characteristics that when an AC 500kV switch is disconnected, the equivalent of a small capacitor exists between the disconnected switch, and electromagnetic induction occurs between the power-off side and the non-power-off side of the switch to form an induced voltage, the voltage on both sides is measured by a voltage transformer, and the size of the induced voltage on the switch unit side before power-on is compared to determine whether the 500kV grounding switch is normally disconnected, whether the isolation switch is normally closed, and whether the three-phase switch is consistently disconnected, thereby ensuring the safe and reliable process of power-on and power-off of the 500kV device.
[0004] The present application provides a method for judging the hot standby state of a voltage output device based on induced voltage, and the specific technical solutions are as follows: The method is used for a device switch loop, and the method includes judging the hot standby state of a switch during power-on, and the specific steps are as follows: S1: Real-time acquisition of auxiliary contact position signals of a grounding switch, an isolation switch, and a circuit breaker switch in a 500kV device switch loop; S2: judging whether the device is not in the hot standby state according to the detected auxiliary contact position signal, if yes, outputting a corresponding prompt, if not, executing the next step; S3: synchronously collecting three-phase phase voltages Ua, Ub, Uc and line voltages Uab, Ubc, Uac on the side to be energized of the circuit breaker switch; S4: judging the voltage according to the three-phase phase voltages and the line voltages on the side to be energized of the circuit breaker switch, and outputting a corresponding prompt if the conditions are not met.
[0005] Further, the device switch circuit comprises an alternating current power supply, a circuit breaker switch and a power output end; the alternating current power supply is electrically connected with the power output end through the circuit breaker switch, and the circuit breaker switch is grounded through the grounding knife switch; the circuit breaker switch is further provided with an isolation switch, and the device switch circuit is further provided with a voltage transformer, which is arranged between the two isolation switches and the alternating current power supply and the power output end, respectively.
[0006] Further, in step S2, the judgment of whether the device is not in the hot standby state is as follows: If any of the grounding knife switches is in the closed position, or any of the isolation knife switches is in the open position, or the circuit breaker switch is in the closed state, it is determined that the device is not in the hot standby state, and a corresponding prompt is output, otherwise the next step is executed.
[0007] Further, in step S4, the voltage judgment comprises induction voltage threshold judgment, induction voltage balance degree judgment and induction voltage out-of-limit judgment. If any of the judgment conditions is not met, a corresponding abnormal prompt is output, and if all the condition judgments are passed, a normal hot standby state is output.
[0008] Further, the induction voltage threshold judgment is as follows: It is judged whether the three-phase phase voltages Ua, Ub, Uc on the side to be energized of the circuit breaker switch are all not less than the set induction voltage threshold value, if yes, the judgment condition is met, and the next condition judgment is executed, otherwise an abnormality of the grounding knife switch is output.
[0009] Further, the induction voltage balance degree judgment is as follows: If |Uab- Ubc |≤K·Uac, and |Ubc- Uac |≤K·Uab, and |Uab- Uac |≤K·Ubc, the judgment condition is met, and the next condition judgment is executed, otherwise an abnormality of the isolation knife switch or the circuit breaker switch is output.
[0010] Further, the induction voltage out-of-limit judgment is as follows: If none of the line voltages exceeds the preset upper limit of induced voltage, the determination condition is satisfied, and a normal hot standby state is output, otherwise, an abnormal switch is output.
[0011] Further, the method further comprises switch power transfer to hot standby state judgment, specifically as follows: Only the auxiliary contact position signal of the circuit breaker switch in the 500kV equipment switch loop is acquired in real time in S1; Step S2; The three-phase line voltages Uab, Ubc and Uac on the side to be powered of the circuit breaker switch are collected in S3; And S4: according to the three-phase line voltages on the side to be powered of the circuit breaker switch, voltage judgment is performed, the voltage judgment is an over-limit judgment of induced voltage, if the condition is not satisfied, a corresponding prompt is output, if it is over-limit, an abnormal switch is output, otherwise, a normal hot standby state is output.
[0012] The beneficial effects of the present application are as follows: 1. The present application solves the problem that the hidden danger of the ground knife switch not being fully separated, the isolation knife switch not being fully closed and the circuit breaker not being fully phase by using auxiliary contact + induced voltage dual criteria, improves the accuracy of judgment, and eliminates the risk of malignant accidents such as closing the ground knife switch and non-full-phase operation.
[0013] 2. By using the characteristic that when the AC 500kV switch is disconnected, the equivalent small capacitor is formed between the switch break, and the electromagnetic induction occurs between the power-off side and the non-power-off side to form an induced voltage, without adding a primary sensor, sampling can be completed on the secondary side of the existing voltage transformer, and the cost is reduced.
[0014] 3. The sequentially executed three-level logic of "threshold-balance-over-limit" can locate the abnormal equipment (ground knife switch, isolation knife switch or circuit breaker) step by step, and the operation and maintenance personnel can directly rush to the fault point according to the prompt, shorten the operation preparation time, and improve the efficiency of switching operation. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 is a schematic diagram of the circuit breaker switch power transfer to hot standby state judgment flow.
[0016] Figure 2 is a schematic diagram of the circuit breaker switch power transfer to hot standby state judgment flow.
[0017] Figure 3 is a maintenance state schematic diagram.
[0018] Figure 4 is a cold standby state schematic diagram.
[0019] Figure 5 is a hot standby state schematic diagram.
[0020] Figure 6 is a running state schematic diagram.
[0021] Figure 7 is a hot standby state switch equivalent schematic diagram.
[0022] Legend: 1-500kV AC power supply, 2-circuit breaker switch, 3-voltage transformer, 4-grounding knife switch, 5-isolation knife switch. DETAILED DESCRIPTION
[0023] In the following description, the technical solutions in the embodiments of the present application are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.
[0024] In the description of the embodiments of the present application, it should be noted that the indicated position or positional relationship is based on the position or positional relationship shown in the drawings, or the position or positional relationship commonly used when the product is used, or the position or positional relationship commonly understood by those skilled in the art, or the position or positional relationship commonly used when the product is used, only for the convenience of describing the present application and simplifying the description, and is not indicative or implied that the indicated device or element must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only used for differentiation and cannot be understood as indicating or implying relative importance.
[0025] In the description of the embodiments of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "set", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0026] Embodiment 1 Embodiment 1 of the present application discloses a voltage output device hot standby state judgment method based on induced voltage, which is used for 500kV AC source output device switch loop, as shown in the figure, the device switch loop includes 500kV AC power supply 1, circuit breaker switch 2 and power output end; the AC power supply is electrically connected with the power output end through the circuit breaker switch 2, and the circuit breaker switch 2 is grounded through the grounding knife switch 4; the circuit breaker switch 2 is also provided with an isolation switch, and the device switch loop is also provided with a voltage transformer 3, which is respectively arranged between the two isolation switches and the AC power supply and the power output end; Figures 3-7 The method comprises determining whether to switch to a hot standby state, as shown in the following specific steps: Figure 1 S1: Real-time acquisition of auxiliary contact position signals of the grounding knife switch 4, the isolation knife switch 5 and the circuit breaker switch 2 in the switch loop of the 500kV equipment; S1: Real-time acquisition of auxiliary contact position signals of the grounding knife switch 4, the isolation knife switch 5 and the circuit breaker switch 2 in the switch loop of the 500kV equipment; Specifically, the auxiliary contact position signals can be read in real time by the substation monitoring background.
[0027] S2: Determining whether the equipment has entered the hot standby state according to the detected auxiliary contact position signals, if yes, terminating the subsequent steps and outputting the corresponding prompt, if not, executing the next step; Specifically, if any of the grounding knife switches 4 is in the closed position, it is determined that the equipment has not entered the hot standby state, the subsequent steps are terminated and the corresponding prompt is output, otherwise the next determination logic is executed. If any of the isolation knife switches 5 is in the open position, it is determined that the equipment has not entered the hot standby state, the subsequent steps are terminated and the corresponding prompt is output, otherwise the next determination logic is executed. If the circuit breaker switch 2 is in the closed state, it is determined that the equipment has not entered the hot standby state, the subsequent steps are terminated and the corresponding prompt is output, otherwise step S3 is executed. Specifically, when all the above determinations are passed, i.e. all the grounding knife switches 4 are in the open state, all the isolation knife switches 5 are in the closed state, and the circuit breaker switch 2 is in the open state, step S3 is executed.
[0028] S3: Synchronous acquisition of three-phase phase voltages Ua, Ub, Uc and line voltages Uab, Ubc, Uac on the side to be energized of the circuit breaker switch 2. S4: Voltage determination according to the three-phase phase voltages and the line voltages on the side to be energized of the circuit breaker switch 2, if the conditions are not met, the corresponding prompt is output.
[0029] The voltage determination comprises induction voltage threshold determination, induction voltage balance degree determination and induction voltage out-of-limit determination. If any of the determination conditions is not met, the corresponding abnormal prompt is output, if all the condition determinations are passed, the hot standby state is normal.
[0030] Specifically, the auxiliary contact position signals can be read in real time by the substation monitoring background. Determining whether the three-phase phase voltages Ua, Ub, Uc on the side to be energized of the circuit breaker switch 2 are all not less than the set induction voltage threshold value, if the three-phase phase voltages on the side to be energized of the circuit breaker switch 2 are all greater than the induction voltage threshold value Umin, i.e. Ua≥Umin & Ub≥Umin & Uc≥Umin, the next determination logic is executed, otherwise it is determined that the grounding knife switch 4 is abnormal and the process is ended. Determine whether the induced voltage meets the balance requirement, i.e., whether it meets (|Uab-Ubc|≤K·Uac&|Ubc-Uac|≤K·Uab&|Uab-Uac|≤K·Ubc). If the condition is met, proceed to the next determination logic; otherwise, output the isolation switch 5 or the switch is abnormal, and end the process; K is the voltage imbalance coefficient. Determine whether the induced voltage exceeds the limit, i.e. whether it satisfies Uab≤Umax&Ubc≤Umax&Uac≤Umax. If the determination condition is met, output the hot standby status is normal, save the data, and end the process. Specifically, when the output hot standby status is normal, the judgment result and time information are combined into a record and stored in the historical database of the substation automation system for subsequent retrieval and traceability.
[0031] If the judgment condition is not met, the output switch is found to be faulty, and the process ends.
[0032] Specifically, in this embodiment, the above method flow also includes: after outputting any abnormal prompt, synchronously writing all voltage measurement values collected this time and the corresponding abnormal type into the local cache, and immediately sending an alarm message to the host computer.
[0033] Example 2 Embodiment 2 of the present invention discloses a method for determining the hot standby status of a voltage output device based on induced voltage, used in the switching circuit of a 500kV AC source output device, such as... Figures 3-7 As shown, the equipment switching circuit includes an AC power supply, a circuit breaker switch 2, and a power output terminal; the AC power supply is electrically connected to the power output terminal via the circuit breaker switch 2, and the two ends of the circuit breaker switch 2 are grounded through the grounding switch 4; the two ends of the circuit breaker switch 2 are also equipped with disconnect switches, and the equipment switching circuit is also equipped with voltage transformers 3, which are respectively installed between the two disconnect switches and the AC power supply and the power output terminal; The methods include determining whether the switch has switched to hot standby mode after a power outage, such as... Figure 2 As shown, the details are as follows: S1: Real-time acquisition of the auxiliary contact position signal of circuit breaker switch 2 in the 500kV equipment switching circuit.
[0034] S2: Based on the detected auxiliary contact position signal, determine whether the device has not entered hot standby mode. If yes, terminate the subsequent steps and output the corresponding prompt. If not, proceed to the next step. Specifically, if the circuit breaker switch 2 is in the closed state, it is determined that the equipment has not entered the hot standby state, the subsequent steps are terminated and a corresponding prompt is output; otherwise, step S3 is executed. S3: Collect the three-phase line voltages Uab, Ubc, and Uac on the side of circuit breaker switch 2 awaiting power supply; S4: According to the circuit breaker switch 2 to be sent to the three-phase line voltage Uab, Ubc, Uac, the induced voltage is determined to be out of limit, and whether the induced voltage is out of limit is determined, as follows: Whether Uab≤Umax&Ubc≤Umax&Uac≤Umax is satisfied, if the determination condition is satisfied, the output hot standby state is normal, and data saving is performed, and the flow is ended; Specifically, when the output hot standby state is normal, the determination result and the time information form a record, which is stored in the historical database of the substation automation system, for subsequent review and traceability.
[0035] If the determination condition is not satisfied, it is output that the switch has an abnormality, and the flow is ended.
[0036] Specifically, in the above method flow, the embodiment further includes: after outputting any abnormal prompt, synchronously write all voltage measurement values collected this time and the corresponding abnormal type into the local cache, and immediately send an alarm message to the upper computer.
[0037] In the embodiment, the reverse power-off operation only retains the out-of-limit determination, which can also find that the circuit breaker is misconnected or the insulation of the break is invalid, ensures the safety of the power-off side, forms a power-on / power-off bidirectional closed loop control, and solves the problem that there is no effective electrical quantity check in the current power-off process.
[0038] The present application is not limited to the foregoing specific embodiments. The present application extends to any new feature or any new combination disclosed in the specification, as well as any new method or process steps or any new combination disclosed.
Claims
1. A method for determining the hot standby status of a voltage output device based on induced voltage, characterized in that, For equipment switching circuits, the method includes determining whether a circuit breaker switch is switched to hot standby mode after being energized, as detailed below: S1: Real-time acquisition of the position signals of grounding switches, isolating switches, and auxiliary contacts of circuit breaker switches in the 500kV equipment switching circuit; S2: Based on the detected auxiliary contact position signal, determine whether the device has not entered hot standby mode. If yes, output the corresponding prompt; otherwise, proceed to the next step. S3: Synchronously collect the three-phase phase voltages Ua, Ub, Uc and line voltages Uab, Ubc and Uac on the side of the circuit breaker switch to be energized; S4: Based on the three-phase phase voltage and line voltage on the side of the circuit breaker to be energized, perform voltage judgment. If the conditions are not met, output the corresponding prompt.
2. The method for determining the hot standby status of a voltage output device based on induced voltage according to claim 1, characterized in that, The equipment switching circuit includes an AC power supply, a circuit breaker switch, and a power output terminal; the AC power supply is electrically connected to the power output terminal via the circuit breaker switch, and the two ends of the circuit breaker switch are grounded through the grounding switch; the two ends of the circuit breaker switch are also equipped with disconnect switches, and the equipment switching circuit is also equipped with voltage transformers, which are respectively installed between the two disconnect switches and the AC power supply and the power output terminal.
3. The method for determining the hot standby status of a voltage output device based on induced voltage according to claim 2, characterized in that, In step S2, determining whether the device has not entered hot standby mode is as follows: If any of the grounding switches is in the closed position, or any of the isolating switches is in the open position, or the circuit breaker is in the closed state, it is determined that the equipment has not entered the hot standby state and a corresponding prompt is output; otherwise, the next step is executed.
4. The method for determining the hot standby status of a voltage output device based on induced voltage according to claim 2, characterized in that, In step S4, the voltage determination includes: induced voltage threshold determination, induced voltage balance determination, and induced voltage exceeding limit determination. If any judgment condition is not met, the corresponding error message will be output. If all judgment conditions are met, the hot standby status will be output as normal.
5. The method for determining the hot standby status of a voltage output device based on induced voltage according to claim 4, characterized in that, The determination of the induced voltage threshold is as follows: Determine whether the three-phase voltages Ua, Ub, and Uc on the side of the circuit breaker to be energized are all not less than the set induced voltage threshold. If so, the judgment condition is met, and the next condition judgment is executed; otherwise, there is an abnormality in the output grounding switch.
6. The method for determining the hot standby status of a voltage output device based on induced voltage according to claim 4, characterized in that, The determination of induced voltage balance is as follows: If |Uab-Ubc|≤K·Uac, and |Ubc-Uac|≤K·Uab, and |Uab-Uac|≤K·Ubc, then the judgment condition is met, and the next condition judgment is executed; otherwise, the output isolation switch or circuit breaker switch is abnormal.
7. The method for determining the hot standby status of a voltage output device based on induced voltage according to claim 4, characterized in that, The determination of induced voltage exceeding the limit is as follows: If none of the line voltages exceed the preset upper limit of the induced voltage, the judgment condition is met and the output hot standby state is normal; otherwise, the output switch is abnormal.
8. The method for determining the hot standby status of a voltage output device based on induced voltage according to any one of claims 1-7, characterized in that, The method also includes determining whether the switch has switched to hot standby mode after power is supplied, as detailed below: Only execute S1 to obtain the auxiliary contact position signal of the circuit breaker switch of the 500kV equipment switching circuit in real time; Step S2; S3 collects the three-phase line voltages Uab, Ubc, and Uac on the side of the circuit breaker switch to be energized. And S4: Based on the three-phase line voltage on the side of the circuit breaker switch to be energized, a voltage judgment is performed. The voltage judgment is an induced voltage over-limit judgment. If the condition is not met, a corresponding prompt is output. If the limit is exceeded, the switch is output as abnormal. Otherwise, the hot standby status is output as normal.