A control loop break detection alarm device for protecting a TT&C device

Abstract

The utility model provides a kind of control loop break detection alarm device for protecting measurement and control device, comprising: protection measurement and control device, integrated in the light couple detection circuit of closing circuit of the protection measurement and control device, and the MCU control system of the electric connection of the light couple detection circuit;The light couple detection circuit includes closing monitoring light couple circuit and opening monitoring light couple circuit, respectively in the closing circuit and the opening circuit of circuit breaker Stringing;The light couple detection circuit is used to transmit the detected loop state signal to the MCU control system by the way of input quantity;The MCU control system is used to determine whether control loop is broken and triggers alarm according to the circuit breaker position and loop state signal judgment control loop is broken.The utility model is broken by light couple circuit acquisition loop state signal to realize determination, with the advantages of low cost, high integration.

Description

Technical Field

[0001] This utility model relates to the field of power distribution network control circuit disconnection detection technology, specifically a control circuit disconnection detection alarm device for protection and control devices. Background Technology

[0002] Circuit breaker control circuits are a crucial component of power systems, enabling timely disconnection of faulty points during power system failures to protect equipment and personnel. However, due to various reasons, control circuits may experience disconnections. A disconnected control circuit prevents the circuit breaker from functioning properly, hindering its ability to promptly disconnect faults and potentially leading to equipment damage or even escalation of the accident. Monitoring the circuit status allows for timely detection and alarm mechanisms, preventing such situations and improving system reliability.

[0003] A simplified schematic diagram of the tripping and closing circuit of the circuit breaker control circuit is shown below. Figure 1 As shown, +KM and -KM represent the positive and negative terminals of the operating power supply, QF is the circuit breaker auxiliary contact, and HQ and TQ are the closing and tripping coils, respectively.

[0004] Assuming the circuit breaker is in the open position, when the protection and control device sends a closing command, the closing output contact closes, forming a circuit through +KM → closing output contact → QF → HQ → -KM. The closing coil HQ is energized, and the circuit breaker closes. After the circuit breaker completes the closing action, the normally closed contact of QF opens the closing circuit, and the normally open contact closes, preparing for the next operation. When the circuit breaker is in the closed position, its opening action principle is similar to the closing action process.

[0005] Traditionally, a TWJ (Trip-Way Relay) and HWJ (Close-Way Relay) are added to the control circuit to monitor the integrity of the trip and close circuits. The principle behind the control circuit disconnection signal is to monitor the circuit's integrity through trip relays (TWJ) and close relays (HWJ). For example... Figure 2 The diagram shows that the normally closed contact of the trip relay (TWJ) and the normally closed contact of the close relay (HWJ) are connected in series to form a signal circuit that is connected to the protection and control device. Only when the integrity of the switch tripping or closing circuit is compromised will the TWJ and HWJ relays lose voltage at the same time, and their normally closed contacts will close simultaneously, thus connecting the circuit. The protection and control device will then detect this signal and report a disconnection alarm signal. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model provides a control circuit disconnection detection and alarm device that does not require external relays and is integrated into the protection and control device. It achieves disconnection judgment by collecting circuit status signals through optocoupler circuit, and has the advantages of low cost and high integration.

[0007] A control circuit disconnection detection and alarm device for a protection and control device includes: a protection and control device, an optocoupler detection circuit integrated into the closing circuit of the protection and control device, and an MCU control system electrically connected to the optocoupler detection circuit.

[0008] The optocoupler detection circuit includes a closing monitoring optocoupler circuit and a opening monitoring optocoupler circuit, which are connected in series in the closing circuit and the opening circuit of the circuit breaker, respectively.

[0009] The optocoupler detection circuit is used to transmit the detected loop status signal to the MCU control system via an input signal.

[0010] The MCU control system is used to determine whether the control circuit is disconnected and trigger an alarm based on the circuit breaker position and circuit status signals.

[0011] Furthermore, a current-limiting resistor is connected in series in both the closing monitoring optocoupler circuit and the opening monitoring optocoupler circuit. The resistance value of the current-limiting resistor is configured such that the current when the optocoupler circuit is turned on is lower than the starting current threshold of the circuit breaker's opening and closing coils.

[0012] Furthermore, the MCU control system determines whether the control circuit is disconnected and triggers an alarm based on the circuit breaker position and circuit status signals, including:

[0013] When the circuit breaker is in the open position, under normal conditions, the closing monitoring optocoupler circuit is on and the closing circuit status signal is low; the opening monitoring optocoupler circuit is off and the opening circuit status signal is high; if the closing circuit is disconnected, the closing monitoring optocoupler circuit is off and the closing circuit status signal is high. At this time, both the opening and closing circuit status signals are high and the duration exceeds the set delay, triggering a disconnection alarm.

[0014] When the circuit breaker is in the closed position, under normal conditions, the trip monitoring optocoupler circuit is on, and the trip circuit status signal is low; the closing monitoring optocoupler circuit is off, and the closing circuit status signal is high; if the trip circuit is disconnected, the trip monitoring optocoupler circuit is off, and the trip circuit status signal is high. At this time, both the trip and closing circuit status signals are high and the duration exceeds the set delay, triggering a disconnection alarm.

[0015] This invention integrates an optocoupler detection circuit, avoiding the reliance on external relays in traditional technologies. It has the advantages of low cost and high integration, and can effectively monitor the status of the control loop and provide timely alarms to prevent equipment damage or accident escalation caused by circuit breaker failure. Attached Figure Description

[0016] Figure 1 This is a simplified diagram of the tripping and closing principle of the circuit breaker control circuit;

[0017] Figure 2 This is a schematic diagram of the monitoring principle of the control circuit of an existing circuit breaker;

[0018] Figure 3 This is a schematic diagram of the control circuit disconnection detection and alarm device for protecting and controlling the device according to this utility model. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0020] Please see Figure 3 This utility model provides a control circuit disconnection detection alarm device for a protection and control device, including a protection and control device, an optocoupler detection circuit integrated into the closing circuit of the protection and control device, and an MCU control system electrically connected to the optocoupler detection circuit.

[0021] The optocoupler detection circuit is divided into a closing monitoring optocoupler circuit and a opening monitoring optocoupler circuit, which are connected in series in the closing circuit and the opening circuit of the circuit breaker, respectively. A current-limiting resistor is connected in series in the optocoupler circuit to ensure that the current is much lower than the starting current threshold of the opening and closing coils when the circuit is turned on, thus avoiding malfunction.

[0022] The optocoupler detection circuit transmits the loop status signal (high / low level) to the MCU control system via an input signal. The MCU control system determines whether the circuit is open based on the circuit breaker position (open / closed) and the loop status signal (as shown in Table 1).

[0023] Table 1

[0024]

[0025] When the circuit breaker is in the open position: Under normal conditions, the circuit breaker auxiliary contact QF is normally closed, the closing monitoring optocoupler circuit is on (the closing circuit status signal is low level), and the opening monitoring optocoupler circuit is off (the opening circuit status signal is high level); if the closing circuit is disconnected, the closing monitoring optocoupler circuit is off (the closing circuit status signal becomes high level). At this time, both the opening and closing circuit status signals are high level and continue for more than the set delay, and the MCU control system triggers a disconnection alarm.

[0026] When the circuit breaker is closed: Under normal conditions, the normally open QF circuit breaker is closed, the trip monitoring optocoupler circuit is on (the trip circuit status signal is low level), and the closing monitoring optocoupler circuit is off (the closing circuit status signal is high level); if the trip circuit is disconnected, the trip monitoring optocoupler circuit is off (the trip circuit status signal becomes high level). At this time, both the trip and closing circuit status signals are high level and continue for more than the set delay, triggering a disconnection alarm in the MCU control system.

[0027] This invention integrates an optocoupler detection circuit into the opening and closing circuits within the protection and control device. This circuit status signal is collected and transmitted to the MCU control system. The MCU determines whether both the opening and closing circuit status signals are high-level and remain high for more than a specified delay time, triggering a disconnection alarm. This device requires no external relays, offering advantages such as low cost and high integration. It effectively monitors the integrity of the control circuit, preventing accidents caused by circuit breaker failure.

[0028] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A control circuit disconnection detection and alarm device for protecting and controlling a measurement and control device, characterized in that, include: The protection and control device, the optocoupler detection circuit integrated into the closing circuit of the protection and control device, and the MCU control system electrically connected to the optocoupler detection circuit; The optocoupler detection circuit includes a closing monitoring optocoupler circuit and a opening monitoring optocoupler circuit, which are connected in series in the closing circuit and the opening circuit of the circuit breaker, respectively. The optocoupler detection circuit is used to transmit the detected loop status signal to the MCU control system via an input signal. The MCU control system is used to determine whether the control circuit is disconnected and trigger an alarm based on the circuit breaker position and circuit status signals.

2. The control loop disconnection detection and alarm device according to claim 1, characterized in that, The closing monitoring optocoupler circuit and the opening monitoring optocoupler circuit are respectively connected in series with current-limiting resistors. The resistance value of the current-limiting resistors is configured so that the current when the optocoupler circuit is turned on is lower than the starting current threshold of the circuit breaker's opening and closing coils.

3. The control loop disconnection detection and alarm device according to claim 1, characterized in that, The MCU control system determines whether the control circuit is disconnected and triggers an alarm based on the circuit breaker position and circuit status signals, including: When the circuit breaker is in the open position, under normal conditions, the closing monitoring optocoupler circuit is on and the closing circuit status signal is low; the opening monitoring optocoupler circuit is off and the opening circuit status signal is high; if the closing circuit is disconnected, the closing monitoring optocoupler circuit is off and the closing circuit status signal is high. At this time, both the opening and closing circuit status signals are high and the duration exceeds the set delay, triggering a disconnection alarm. When the circuit breaker is in the closed position, under normal conditions, the trip monitoring optocoupler circuit is on, and the trip circuit status signal is low; the closing monitoring optocoupler circuit is off, and the closing circuit status signal is high; if the trip circuit is disconnected, the trip monitoring optocoupler circuit is off, and the trip circuit status signal is high. At this time, both the trip and closing circuit status signals are high and the duration exceeds the set delay, triggering a disconnection alarm.

Images