A method and system for monitoring the state of a protective relay operating circuit lockout

Abstract

The application discloses a kind of relay protection operation loop locking state monitoring method and system, comprising the following steps: step 1, setting voltage active monitoring port obtains the first end and the end voltage of locking loop and relay protection operation loop;Step 2, construct active detection loop based on weak voltage micro-current and be connected with locking loop;Step 3, according to the voltage at both ends of locking loop, judge whether to meet the trigger condition of active detection mechanism, when meeting, active detection loop will pulse signal be injected into locking loop and detect the integrity of locking loop.The application can establish fast detection method, realize the detection of locking loop at the same time, without mis-triggering action outlet.

Description

Technical Field

[0001] This invention relates to the field of power automation technology, and more specifically, to a method and system for monitoring the interlocking status of relay protection operation circuits. Background Technology

[0002] In recent years, the reliability of substation switching operations has become a crucial component of modern substation power supply reliability and operational safety. To prevent misoperation by substation maintenance personnel, disconnect switches must possess comprehensive misoperation prevention functions, primarily divided into mechanical interlocking and electrical interlocking, with the latter being indispensable. Substation misoperation prevention requires a dual approach: in addition to mechanical and electrical locking, cross-bay electrical equipment should also have logic locking functions to further reduce the risk of misoperation. The operating methods of maintenance personnel and the quality of electrical secondary components directly determine whether the electrical operation of disconnect switches can be carried out smoothly.

[0003] Currently, substations lack the capability to monitor the electrical operation interlocking circuits of disconnecting switches. If maintenance personnel are unable to operate the disconnecting switch during operation, it not only reduces the reliability of power supply but also further increases the safety risks associated with manually operating the disconnecting switch. In such cases, maintenance personnel must arrive on-site to handle the situation. Existing technology lacks monitoring methods for the electrical operation interlocking circuits of disconnecting switches. Furthermore, since the electrical interlocking circuits are composed of series nodes, any unnecessary series monitoring can compromise the integrity of the interlocking circuit. Therefore, maintenance personnel often struggle to provide effective descriptions of the phenomena observed in the electrical interlocking circuits, making it difficult for maintenance personnel to develop emergency repair strategies in advance.

[0004] Therefore, it is necessary to develop reasonable and safe active monitoring methods for interlocking circuits to improve the status monitoring level of interlocking circuits and fill the current monitoring gaps. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method for monitoring the interlocking status of relay protection operation circuits, which can monitor the integrity of the interlocking circuits of relay protection operation circuits in real time.

[0006] The present invention adopts the following technical solution.

[0007] A method for monitoring the interlocking status of a relay protection operating circuit includes the following steps:

[0008] Step 1: Set up a voltage monitoring port to obtain the start and end voltages of the interlocking circuit and the relay protection operation circuit;

[0009] Step 2: Construct an active detection loop based on weak voltage and microcurrent and connect it to the lockout loop;

[0010] Step 3: Determine whether the triggering conditions of the active detection mechanism are met based on the voltage across the interlocking circuit.

[0011] When the conditions are met, the active detection circuit injects a pulse signal into the locking circuit to detect the integrity of the locking circuit.

[0012] Preferably, step 1 further includes the following steps:

[0013] Step 1-1: Connect the active voltage monitoring port in parallel across both ends of the interlocking circuit, and connect the interlocking circuit in series with the relay protection operation circuit.

[0014] Steps 1-2: Obtain the voltage U at the beginning of the operating circuit through the voltage and active monitoring multiplexing port. KM+ Terminal voltage U KM- The voltage U at the beginning of the blocking circuit BSH The voltage U at the end of the lockout circuit BSE .

[0015] Preferably, the voltage and active monitoring multiplex port functions to acquire voltage, actively monitor and output 5V voltage. The internal logic enables the switching of the multiplex port's functions, and the multiplex port is used to realize voltage input or output.

[0016] Preferably, steps 1-3 further include:

[0017] When the voltage across the operating circuit and the voltage across the locking circuit satisfy U KM+ =U BSH or U KM- =U BSE At that time, it is determined that the interlocking circuit has been put into operation.

[0018] Preferably, in step 2, the constructed active detection circuit further includes: setting a detection circuit consisting of a 3.3V trigger voltage and a 107.5 kΩ input impedance at the beginning of the lockout circuit, and generating a microcurrent as a pulse signal by triggering the trigger voltage.

[0019] Preferably, in step 2, the active detection circuit further includes an interrupt timer, which controls the pulse width of the pulse signal to 5 milliseconds.

[0020] Preferably, step 3 further includes the following steps:

[0021] Step 3-1: Determine whether the active detection mechanism triggering conditions are met based on the voltage across the interlocking circuit.

[0022] Step 3-2: When the triggering conditions of the active detection mechanism are met, the active detection will actively monitor the interlocking circuit by injecting pulse signals.

[0023] Step 3-3: Determine whether the interlocking circuit is intact based on the voltage across the interlocking circuit after the pulse signal is injected.

[0024] Preferably, step 3-1 further includes:

[0025] When the voltage at the beginning of the locking circuit is U BSH and terminal voltage U BSE Satisfy U BSH =U BSE When the value is 0, it is determined that the triggering condition of the active detection mechanism is met.

[0026] Preferably, step 3-3 further includes:

[0027] After the pulse signal is injected into the locking circuit, it is determined whether the voltage at the beginning and end of the locking circuit meets the following requirements:

[0028] (U BSH -U BSE ) / U BSH *100% < 10%

[0029] If the voltage across the two ends of the locking circuit satisfies the above formula, the locking circuit is considered intact; otherwise, the locking circuit is considered faulty.

[0030] The present invention also provides a relay protection operation circuit lockout status monitoring system, characterized in that it includes: a voltage and active monitoring multiplexing port, an active detection circuit, a control module and a judgment module;

[0031] The voltage and active monitoring multiplexing port can acquire voltage and output voltage, and the voltage and active monitoring multiplexing port is connected in parallel to the beginning and end of the blocking loop;

[0032] The active detection circuit is used to generate pulse signals and also includes trigger voltage and input impedance, which can generate a 20 microamp pulse signal as a detection current;

[0033] The control module is used to control the pulse width of the pulse signal, so that the pulse width of the trigger voltage is 5 milliseconds;

[0034] The judgment module is used to determine whether the blocking circuit is intact based on the voltage at the beginning and end of the blocking circuit obtained from the active monitoring multiplexing port.

[0035] The beneficial effects of the present invention are that, compared with the prior art, the present invention is characterized by being connected in parallel to the electric operation interlocking circuit of the disconnecting switch, without affecting the reliability and safety of the electric operation interlocking circuit itself, and the indication is clear, which improves the efficiency of switching operation and emergency repair. At the same time, the monitoring device has a simple circuit and will not form related parasitic circuits, thereby avoiding the impact on the original circuit.

[0036] This invention employs a parallel voltage monitoring method and can also actively monitor the interlocking circuit by judging its connection status, thus identifying the working status of the interlocking circuit and determining whether it is in operation. It also constructs an active detection mechanism to detect the integrity of the interlocking circuit through weak voltage and microcurrent. Through chip-based rapid control, it achieves millisecond-level rapid detection, ensuring that the interlocking circuit is detected without erroneously triggering the action output. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the overall process of the relay protection operation circuit lockout status monitoring method of the present invention;

[0038] Figure 2 This is a diagram of the voltage and active monitoring multiplexing port in this invention;

[0039] Figure 3 This is the external wiring diagram of the locking circuit in this invention;

[0040] Figure 4 This is a schematic diagram of the overall structure of the relay protection operation circuit lockout status monitoring system of the present invention. Detailed Implementation

[0041] The present application will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and should not be construed as limiting the scope of protection of the present application.

[0042] like Figure 1 As shown, the present invention provides a method for monitoring the interlocking status of a relay protection operating circuit, which specifically includes the following steps:

[0043] Step 1: Set up an active voltage monitoring port to acquire the start and end voltages of the interlocking circuit and the relay protection operation circuit;

[0044] Specifically, the operating status of the interlocking circuit is determined by the voltage across the two ends of the interlocking circuit. Step 1 also includes the following steps:

[0045] Step 1-1: Connect the active voltage monitoring port in parallel across both ends of the interlocking circuit, and connect the interlocking circuit in series with the relay protection operation circuit.

[0046] Among them, the active voltage monitoring port is used to acquire voltage, such as Figure 2 As shown, the active voltage monitoring port is connected in parallel to the first end BSH_1_IN and the last end BSE_1_IN of the lockout circuit; as Figure 3 As shown, Figure 3 This is the external wiring diagram for the interlocking circuit. When the interlocking circuit is connected in series with the relay protection operating circuit, both ends or one end of the interlocking circuit are energized.

[0047] Specifically, the active voltage monitoring port also includes a first resistor R178, a second resistor R179, a third resistor R181, a fourth resistor R186, a fifth resistor R189, a capacitor C94, and a diode D24.

[0048] Among them, the first resistor R178, the second resistor R179, and the third resistor R181 are connected in series, and one end of the first resistor R178 is connected to the first end BSH_1_IN of the locking circuit.

[0049] One end of the third resistor R181 is connected to the end of the locking circuit, BSE_1_IN. One end of the fourth resistor R186 is connected in series with the first resistor R178 and the second resistor R179, and the other end is grounded.

[0050] The third resistor R181, capacitor C94, fifth resistor R189 and diode D24 are connected in sequence to form a circuit. Capacitor C94 and fifth resistor R189 are connected to the reference port AIN2N respectively. The difference between the voltage at the first end BSH_1_IN of the lockout circuit and the voltage at the reference port AIN2N is the magnitude of the measured voltage.

[0051] The negative terminal of diode D24 is connected to the second resistor R179 and the third resistor R181, respectively, while the positive terminal is grounded.

[0052] Specifically, the first resistor R178 has a resistance of 100KΩ, the second resistor R179 has a resistance of 7.5KΩ, the third resistor R181 and the fifth resistor R189 both have a resistance of 10KΩ, the fourth resistor R186 has a resistance of 3KΩ, and the capacitor C94 has a capacitance of 1nF.

[0053] Steps 1-2: Obtain the operating circuit start voltage UKM+, end voltage UKM-, lockout circuit start voltage UBSH, and lockout circuit end voltage UBSE through the active voltage monitoring port.

[0054] Step 2: Construct an active detection loop based on weak voltage and microcurrent and connect it to the lockout loop;

[0055] The main feature of the active detection mechanism employed in this invention is its ability to transmit weak voltage and low current detection signals. Since relays in the operating circuit include both voltage-driven and current-driven types, with tripping circuits primarily being current-driven, this invention proposes a method for transmitting microampere-level detection signals in its active detection mechanism.

[0056] Specifically, the constructed active detection circuit also includes a detection circuit consisting of a 3.3V trigger voltage and a 107.5kΩ input impedance at the beginning of the lockout circuit. A microcurrent is generated as a pulse signal by triggering the voltage. Specifically, with the 3.3V trigger voltage at the pin, combined with relay control and impedance design, the detection current stabilizes at 20µA when the input impedance is 107.5kΩ.

[0057] The injected pulse signal should meet the principle of reasonable interval and narrow pulse width. In this embodiment, the pulse signal is injected once every 15 minutes and the pulse width of the injected signal is 5ms, that is, active monitoring is performed once every 15 minutes.

[0058] Furthermore, in order to establish a rapid detection method, the detection of the interlocking circuit is achieved through chip control, thereby realizing millisecond-level detection and ensuring that the action exit is not mistakenly triggered while the interlocking circuit is being detected.

[0059] Specifically, the core of the rapid detection method is to control the pulse width of the pulse signal through an interrupt timer to achieve millisecond-level detection control. Since the trip pulse width is generally above 50 milliseconds in actual operation, and the reliable trigger pulse width needs to be maintained at 100 milliseconds, this invention sets the 3.3V detection voltage pulse width to 5 milliseconds, which can effectively avoid false triggering of the lockout circuit and mis-connection.

[0060] Step 3: Determine whether the triggering conditions of the active detection mechanism are met based on the voltage across the locking circuit. When the conditions are met, the active detection circuit injects a pulse signal into the locking circuit to detect the integrity of the locking circuit.

[0061] Specifically, step 3 also includes:

[0062] Step 3-1: Determine whether the active detection mechanism triggering conditions are met based on the voltage across the interlocking circuit.

[0063] Where the voltage at the beginning of the blocking circuit is U BSH and terminal voltage U BSE Satisfy U BSH =U BSE When the value is 0, it is determined that the triggering condition of the active detection mechanism is met.

[0064] Step 3-2: When the triggering conditions of the active detection mechanism are met, the active detection loop actively monitors the interlocking loop by injecting pulse signals.

[0065] Step 3-3: Determine whether the interlocking circuit is intact based on the voltage across the interlocking circuit after the pulse signal is injected.

[0066] Specifically, after the pulse signal is injected into the locking circuit, it is determined whether the voltage at the beginning and end of the locking circuit meets the following requirements:

[0067] (U BSH -U BSE ) / U BSH *100% < 10%

[0068] If the voltage across the two ends of the locking circuit satisfies the above formula, the locking circuit is considered intact; otherwise, the locking circuit is considered faulty.

[0069] like Figure 4 As shown, the present invention also proposes a relay protection operation circuit lockout status monitoring system. The above-mentioned relay protection operation circuit lockout status monitoring method can be implemented based on this system. Specifically, the system includes a voltage and active monitoring multiplexing port, an active detection circuit, a control module, and a judgment module.

[0070] Among them, the voltage and active monitoring multiplexing port can acquire voltage and output voltage, and it is connected in parallel to the beginning and end of the blocking circuit;

[0071] The active detection circuit is used to generate a pulse signal, which includes a trigger voltage and an input impedance. The trigger voltage is 3.3V and the input impedance is 107.5 kΩ, generating a 20µA pulse signal as the detection current.

[0072] The control module is used to control the pulse width of the pulse signal, so that the pulse width of the trigger voltage is 5 milliseconds;

[0073] The judgment module is used to determine whether the blocking circuit is intact based on the voltage at the beginning and end of the blocking circuit obtained from the active monitoring multiplexing port.

[0074] The beneficial effects of this invention are that, compared with the prior art, this invention uses a parallel voltage method to monitor electrical interlocking circuits composed of series nodes, avoiding damage to the integrity of the interlocking circuit caused by traditional series monitoring methods. Furthermore, the monitoring method of this invention actively monitors the circuit based on its operating status, determining whether it is in operation.

[0075] Any unnecessary series monitoring will pose a risk to the integrity of the interlocking circuit. Therefore, this patent adopts parallel voltage monitoring and will also actively monitor by judging the interlocking circuit connection status.

[0076] The applicant of this invention has provided a detailed description of the embodiments of the invention in conjunction with the accompanying drawings. However, those skilled in the art should understand that the above embodiments are merely preferred embodiments of the invention. The detailed description is only intended to help readers better understand the spirit of the invention and is not intended to limit the scope of protection of the invention. On the contrary, any improvements or modifications made based on the inventive spirit of the invention should fall within the scope of protection of the invention.

Claims

1. A method for monitoring the interlocking status of a relay protection operating circuit, characterized in that, Includes the following steps: Step 1: Set up a voltage monitoring port to obtain the start and end voltages of the interlocking circuit and the relay protection operation circuit; connect the active voltage monitoring port in parallel to the start and end of the interlocking circuit. Step 1 also includes the following steps: Step 1-1: Connect the voltage and active monitoring multiplexing port in parallel across the two ends of the interlocking circuit, and connect the interlocking circuit in series with the relay protection operation circuit. Steps 1-2: Obtain the voltage U at the beginning of the operating circuit through the voltage and active monitoring multiplexing port. KM+ Terminal voltage U KM- The voltage U at the beginning of the blocking circuit BSH The voltage U at the end of the lockout circuit BSE ; Steps 1-3 also include: When the voltage across the operating circuit and the voltage across the locking circuit satisfy U KM+ =U BSH or U KM- =U BSE At that time, it is determined that the interlocking circuit has been put into operation; Step 2: Construct an active detection loop based on weak voltage and microcurrent and connect it to the lockout loop; In step 2, the constructed active detection circuit also includes: setting a detection circuit consisting of a 3.3V trigger voltage and a 107.5 kΩ input impedance at the beginning of the lockout circuit, and generating a microcurrent as a pulse signal by triggering the trigger voltage; Step 3: Determine whether the triggering conditions of the active detection mechanism are met based on the voltage across the locking circuit. When the conditions are met, the active detection circuit injects a pulse signal into the locking circuit to detect the integrity of the locking circuit.

2. The method for monitoring the interlocking status of a relay protection operating circuit according to claim 1, characterized in that: The voltage and active monitoring multiplex port is used to acquire voltage, actively monitor and output 5V voltage. The internal logic enables the switching of the multiplex port's functions, and the multiplex port is used to realize voltage input or output.

3. The method for monitoring the interlocking status of a relay protection operating circuit according to claim 1, characterized in that: In step 2, the active detection circuit also includes an interrupt timer, which controls the pulse width of the pulse signal to 5 milliseconds.

4. The method for monitoring the interlocking status of a relay protection operating circuit according to claim 1, characterized in that: Step 3 also includes the following steps: Step 3-1: Determine whether the active detection mechanism triggering conditions are met based on the voltage across the interlocking circuit. Step 3-2: When the triggering conditions of the active detection mechanism are met, the active detection will actively monitor the interlocking circuit by injecting pulse signals. Step 3-3: Determine whether the interlocking circuit is intact based on the voltage across the interlocking circuit after the pulse signal is injected.

5. The method for monitoring the interlocking status of a relay protection operating circuit according to claim 4, characterized in that: Step 3-1 further includes: When the voltage at the beginning of the locking circuit is U BSH and terminal voltage U BSE Satisfy U BSH =U BSE When the value is 0, it is determined that the triggering condition of the active detection mechanism is met.

6. The method for monitoring the interlocking status of a relay protection operating circuit according to claim 4, characterized in that: Step 3-3 further includes: After the pulse signal is injected into the locking circuit, it is determined whether the voltage at the beginning and end of the locking circuit meets the following requirements: (IN BSH -IN BSE ) / IN BSH *100%<10% If the voltage across the two ends of the locking circuit satisfies the above formula, the locking circuit is considered intact; otherwise, the locking circuit is considered faulty.

7. A relay protection operation circuit interlocking status monitoring system for implementing the relay protection operation circuit interlocking status monitoring method according to any one of claims 1 to 6, characterized in that, Includes: voltage and active monitoring multiplexing port, active detection loop, control module and judgment module; The voltage and active monitoring multiplexing port can acquire voltage and output voltage, and the voltage and active monitoring multiplexing port is connected in parallel to the beginning and end of the blocking loop; The active detection circuit is used to generate pulse signals and also includes trigger voltage and input impedance, which can generate a 20 microamp pulse signal as a detection current; The control module is used to control the pulse width of the pulse signal, so that the pulse width of the trigger voltage is 5 milliseconds; The judgment module is used to determine whether the blocking circuit is intact based on the voltage at the beginning and end of the blocking circuit obtained from the active monitoring multiplexing port.

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