Circuit breaker tripping control loop

Abstract

The utility model provides a circuit breaker tripping control loop, and relates to the technical field of circuit breaker control. The circuit breaker tripping control loop comprises a tripping control contact, one end of which is connected with the positive electrode of the control power supply and the other end of which is connected with a tripping holding relay coil; the other end of the trip-out holding relay coil is connected with a circuit breaker normally-open auxiliary contact. The other end of the circuit breaker normally-open auxiliary contact is connected with a tripping coil; the other end of the tripping coil is connected with the cathode of the current-limiting voltage-stabilizing module; the anode of the current-limiting voltage-stabilizing module is connected with the cathode of the control power supply and is used for limiting grounding current; the normally open contact of the trip-out holding relay is connected in parallel with the trip-out control contact; one end of the closing monitoring relay coil is connected with the positive electrode of the control power supply, and the other end is connected between the tripping control contact and the circuit breaker normally-open auxiliary contact; the monitoring resistor is connected in parallel with the current-limiting voltage-stabilizing module. According to the invention, when the terminal or the cable between the tripping control contact and the tripping holding relay is grounded, the circuit breaker is prevented from being tripped by mistake.

Description

Technical Field

[0001] The present application relates to the technical field of circuit breaker control, for example, to a circuit breaker tripping control circuit. Background Art

[0002] The circuit breaker is an important power equipment. The circuit breaker trip control circuit is the interface for operating the circuit breaker. Secondary equipment such as measurement, control, and protection can all be tripped through the circuit breaker trip control circuit. The relevant technical solution is the same as the solution principle disclosed in utility models CN202564931U and CN211629854U. Figure 1 The schematic diagram of the conventional circuit breaker tripping control circuit is shown, and the circuit breaker tripping control process is:

[0003] Before tripping, the circuit breaker is in the closed position and QF is in the closed state. As long as TJ is closed, KM+, TJ, TBJ coil, QF, TQ, and KM- form a path, and the circuit breaker starts to trip. The current in the path drives TBJ to operate, and the normally open contact of TBJ closes to form a holding circuit. Even if TJ is disconnected, KM+, TBJ contacts, TBJ coil, QF, TQ, and KM- still form a path. Once the trip is successful, QF automatically opens, cutting off the path, causing TBJ to return, and the TBJ contacts are disconnected, and the trip is completed.

[0004] In the related art, when the terminal or cable between the trip control contact TJ and the coil of the trip holding relay TBJ is grounded, the circuit breaker may trip erroneously. Many substations have experienced circuit breaker tripping accidents caused by insulation degradation, instrument misuse (measuring voltage with the resistance range of a multimeter) and grounding.

[0005] The principle of the above DC system grounding causing the circuit breaker to trip incorrectly is as follows: Figure 2 The schematic diagram of conventional false tripping is shown in FIG.

[0006] The resistances R+ and R- to the ground of KM+ and KM- are equal. In normal operation, the voltage difference between KM+ and KM- and the ground is 0.5U. N ; R+, R- are much larger than the coil resistance R of the trip coil TQ TQ , R TQ Much larger than the tripping holding relay TBJ coil resistance R TBJ .

[0007] When the circuit breaker is closed, QF is closed, and when the contact TJ and the TBJ coil are grounded, the charging current of C+ and the discharging current of C- both pass through the TBJ coil. Considering that R+ and R- are much larger than R TQ , R TQ Much larger than R TBJ , ignoring R+, R-, R TBJ, the instantaneous value of the maximum grounding capacitance current through the TBJ coil and TQ is:

[0008]

[0009] Rated tripping current of circuit breaker I TZ For U N / R TQ , that is, the above I C Reach 50%I TZ .

[0010] GB / T 14285-2006 Technical Specification for Relay Protection and Safety Automatic Devices stipulates that the starting current of the trip-holding relay should not be greater than 50% of the rated tripping current. This regulation is followed in engineering implementation. The starting current of the adaptive trip-holding relay (such as the scheme disclosed in invention patent CN100495853C) is lower.

[0011] Therefore, when the terminal or cable between the trip control contact TJ and the coil of the trip holding relay TBJ is grounded, the grounding capacitance current during the grounding process will drive the TBJ relay to operate. After TBJ operates, its normally open contacts close to form a holding loop, causing the circuit breaker to trip incorrectly. Utility Model Content

[0012] The utility model aims to provide a circuit breaker trip control circuit, which can avoid the situation that the circuit breaker trips incorrectly when the terminal or cable between the trip control contact TJ and the coil of the trip holding relay TBJ in the circuit breaker trip control circuit is grounded.

[0013] According to the first aspect of the present application, a circuit breaker trip control circuit is proposed, comprising: a control power supply, a trip control contact, a trip holding relay coil, a trip holding relay normally open contact, a circuit breaker normally open auxiliary contact, a trip coil, a closing monitoring relay coil, a current limiting and voltage stabilizing module, and a monitoring resistor; wherein one end of the trip control contact is connected to the positive electrode of the control power supply, and the other end is connected to the trip holding relay coil for receiving a circuit breaker trip control signal; the other end of the trip holding relay coil is connected to the circuit breaker normally open auxiliary contact for maintaining the tripping action; the other end of the circuit breaker normally open auxiliary contact is connected to the trip line coil; the other end of the trip coil is connected to the cathode of the current limiting and voltage stabilizing module, which is used to perform a tripping action according to the circuit breaker tripping control signal; the anode of the current limiting and voltage stabilizing module is connected to the negative electrode of the control power supply, which is used to limit the current that can trigger the trip coil to perform a tripping action; the normally open contact of the trip holding relay is connected in parallel with the trip control contact; one end of the closing monitoring relay coil is connected to the positive electrode of the control power supply, and the other end is connected between the trip control contact and the normally open auxiliary contact of the circuit breaker, which is used to monitor the execution of the tripping action of the trip coil; the monitoring resistor is connected in parallel with the current limiting and voltage stabilizing module, which is used to trigger the monitoring action of the closing monitoring relay coil.

[0014] According to some embodiments, the circuit breaker trip control circuit further includes a voltage limiting protection module connected in parallel with the trip holding relay coil and configured to limit the voltage of the trip holding relay coil during the tripping process.

[0015] According to some embodiments, the rated voltage of the trip-holding relay coil is 1.5V, the voltage-limiting protection module includes two diodes connected in series, and the anodes of the diodes in series are connected to the trip control contact; or, the rated voltage of the trip-holding relay coil is 0.5V, the voltage-limiting protection module includes a diode, and the anode of the diode is connected to the trip control contact.

[0016] According to some embodiments, the circuit breaker trip control loop further includes an adjusting resistor connected in parallel with the trip holding relay coil and used to adjust the rated current of the trip holding relay coil.

[0017] According to some embodiments, the adjustment resistor includes a basic adjustment resistor connected in parallel with the trip holding relay coil and used to adjust the rated current of the trip holding relay coil.

[0018] According to some embodiments, the adjustment resistor also includes a jumper and a preset adjustment resistor; wherein the jumper is connected in series with the preset adjustment resistor and then connected in parallel with the trip holding relay coil, wherein the jumper is used to switch different preset adjustment resistors, and the preset adjustment resistor is used to adjust the rated current of the trip holding relay coil according to the switching of the jumper.

[0019] According to some embodiments, three groups of series modules consisting of jumpers and preset adjustment resistors are included: a first series module, a second series module and a third series module; wherein the first series module includes a first jumper and a first preset adjustment resistor connected in series, the second series module includes a second jumper and a second preset adjustment resistor connected in series, and the third series module includes a third jumper and a third preset adjustment resistor connected in series; the first preset adjustment resistor is equal to the parallel resistance of the basic adjustment resistor and the resistance of the trip holding relay coil; the second preset adjustment resistor is equal to 0.5 times the first preset adjustment resistor; and the third preset adjustment resistor is equal to 0.5 times the second preset adjustment resistor.

[0020] According to some embodiments, the rated voltage of the current limiting and voltage stabilizing module is 0.5 times the rated voltage of the control power supply; the sum of the resistance of the monitoring resistor and the resistance of the tripping coil is not greater than 0.1 times the resistance of the closing monitoring relay coil; the rated voltage of the tripping coil is 0.5 times the rated voltage of the control power supply.

[0021] According to some embodiments, the current limiting and voltage stabilizing module includes a voltage regulator tube or a transient suppressor with the same rated voltage.

[0022] According to some embodiments, the other end of the closing monitoring relay coil is connected between the trip holding relay coil and the normally open auxiliary contact of the circuit breaker; or, is connected between the trip control contact and the trip holding relay coil.

[0023] According to the example embodiment, the coordinated work of the trip control contact, the trip holding relay coil, the trip coil and other components ensures that the circuit breaker can trip quickly when the power system fails. The design of the trip holding relay coil and the normally open contact enables the circuit breaker to maintain the trip state after the trip action is executed, ensuring that the trip process is completely executed. The introduction of the closed position monitoring relay coil and the monitoring resistor enables the control loop to have the function of monitoring the execution of the trip action, which helps to timely discover and handle possible faults or abnormal conditions. The current limiting and voltage stabilization module can limit the grounding capacitance current when grounding, prevent false operation, and improve the stability and reliability of the entire control loop.

[0024] According to some embodiments, by introducing a voltage limiting protection module, the voltage of the trip holding relay coil during the tripping process can be limited. The voltage limiting protection module can reduce possible faults and malfunctions, thereby improving the stability and reliability of the entire control loop.

[0025] According to some embodiments, since the forward voltage drop of the diode is about 0.7V, the forward voltage drop of a single diode matches the trip-holding relay coil with a rated voltage of 0.5V. Two diodes connected in series will be able to provide a forward voltage drop of about 1.4V, which matches the trip-holding relay coil with a rated voltage of 1.5V. This ensures that under normal working conditions, the relay coil is supplied with a suitable voltage and is not damaged by excessive voltage. When an abnormally high voltage appears in the circuit, the diode can absorb the excess voltage and prevent it from directly acting on the relay coil, thereby protecting the relay coil from overvoltage damage. By limiting the voltage across the relay coil, the voltage limiting protection module reduces the system instability and failure risk caused by voltage fluctuations or anomalies.

[0026] According to some embodiments, by introducing an adjustment resistor, the rated current of the trip-holding relay coil can be conveniently changed. Reasonable current adjustment helps to optimize the performance of the trip-holding relay. By adjusting the current, it is possible to ensure that the relay coil operates in the best working state, reduce coil heating, magnetic saturation and other problems, thereby improving the reliability and life of the relay.

[0027] According to some embodiments, by introducing a basic adjustment resistor, the rated current of the trip holding relay coil can be preliminarily adjusted to provide a basic range for the entire adjustment process.

[0028] According to some embodiments, by introducing preset adjustment resistors and jumpers, further fine-tuning capability is provided. By switching different preset adjustment resistors through jumpers, the rated current can be accurately adjusted to meet more precise current requirements.

[0029] According to some embodiments, by setting three groups of series modules, each group of modules has a different preset adjustment resistance value, a more precise adjustment of the rated current of the trip-holding relay coil can be achieved. This design makes the current adjustment range wider and can meet the precise adjustment requirements under different working conditions and needs. By setting the first preset adjustment resistance equal to the parallel resistance of the basic adjustment resistance and the trip-holding relay coil resistance, and the subsequent preset adjustment resistance is gradually halved, the optimal current adjustment value can be gradually approached. This gradual approximation method improves the accuracy and efficiency of the adjustment and reduces the uncertainty and complexity in the debugging process.

[0030] According to some embodiments, by setting the rated voltage of the current limiting and voltage stabilizing module to 0.5 times the rated voltage of the control power supply, it is beneficial to effectively limit the grounding capacitance current during the grounding process. The sum of the monitoring resistor and the resistance of the tripping coil is strictly controlled within 0.1 times the resistance of the closed-position monitoring relay coil, so that the closed-position monitoring relay coil can more accurately reflect the working state of the tripping coil. By setting the rated voltage of the tripping coil to 0.5 times the rated voltage of the control power supply, the tripping coil can operate stably under normal working conditions.

[0031] According to some embodiments, the current limiting and voltage stabilizing module includes a voltage regulator tube or a transient suppressor with the same rated voltage, which can make it easier for circuit designers to select the model. Since their rated voltages are consistent, the circuit matching and debugging process can be simplified, thereby improving design efficiency.

[0032] According to some embodiments, by changing the connection position of the closing monitoring relay coil, only the tripping coil can be monitored, or the tripping holding relay coil can also be included in the monitoring range, thereby improving the safety and stability of the entire power system.

[0033] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1) It can effectively avoid the circuit breaker from tripping accidentally when the trip control contact and the trip holding relay coil are grounded.

[0036] 2) The trip-holding relay coil is connected in parallel with the voltage-limiting protection circuit to improve the circuit reliability.

[0037] 3) The rated current of the tripping holding circuit can be adjusted simply and flexibly, which is convenient for project implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is the schematic diagram of the conventional circuit breaker tripping control circuit;

[0039] Figure 2 This is a schematic diagram of the principle of conventional false tripping;

[0040] Figure 3 A wiring diagram of a circuit breaker trip control circuit provided in an embodiment of the present application;

[0041] Figure 4 A wiring diagram of another circuit breaker trip control circuit provided in an embodiment of the present application;

[0042] Figure 5 A schematic diagram of another circuit breaker trip control circuit provided by an embodiment of the present application in the case where a terminal or cable between a trip control contact and a trip holding relay is grounded;

[0043] Figure 6 A schematic diagram of local circuit wiring when using a 0.5V type trip-holding relay provided in an embodiment of the present application.

[0044] Description of reference numerals:

[0045] KM: Control power supply, its rated voltage is U N ; KM+: positive pole of control power supply; KM-: negative pole of control power supply; R+: resistance of KM positive pole to ground; R-: resistance of KM negative pole to ground; R+ and R- are equal; C+: capacitance of KM positive pole to ground; C-: capacitance of KM negative pole to ground;

[0046] TJ: tripping control contact;

[0047] TBJ: trip-hold relay; TBJ coil: trip-hold relay coil, whose coil resistance is R TBJ ;TBJ contact: normally open contact of trip-hold relay;

[0048] QF: Normally open auxiliary contact of circuit breaker;

[0049] TQ: tripping coil, whose coil resistance is R TQ , its rated voltage is U TQ ;

[0050] HWJ: Closed position monitoring relay coil, whose coil resistance is R HWJ ;

[0051] Z1: Current limiting and voltage stabilizing module, its rated voltage is U Z ; R1: monitoring resistor;

[0052] D1, D2, D3: silicon diodes; R2: basic adjustment resistor; JP1: first jumper, JP2: second jumper, JP3: third jumper; R3: first preset adjustment resistor, R4: second preset adjustment resistor, R5: third preset adjustment resistor. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0054] Figure 3 This is a wiring diagram of a circuit breaker trip control circuit provided in an embodiment of the present application. Figure 3 As shown, the wiring diagram of the circuit breaker trip control circuit provided in the embodiment of the present application includes a control power supply KM, a trip control contact TJ, a trip holding relay coil TBJ coil, a trip holding relay normally open contact TBJ contact, a circuit breaker normally open auxiliary contact QF, a trip coil TQ, a closing monitoring relay coil HWJ, a current limiting and voltage stabilizing module Z1 and a monitoring resistor R1; wherein,

[0055] One end of TJ is connected to the positive pole of the control power supply, and the other end is connected to the TBJ coil for receiving the circuit breaker tripping control signal; the other end of the TBJ coil is connected to QF for maintaining the tripping action; the other end of QF is connected to TQ; the other end of TQ is connected to the cathode of Z1 for performing the tripping action according to the circuit breaker tripping control signal; the anode of Z1 is connected to the negative pole of the control power supply for limiting the grounding current; the TBJ contact is connected in parallel with TJ; one end of HWJ is connected to KM+, and the other end is connected between TJ and QF for monitoring the execution of the tripping action of TQ; R1 is connected in parallel with Z1 for triggering the monitoring action of the closing monitoring relay coil.

[0056] The circuit breaker tripping control process is as follows: before tripping, the circuit breaker is in the closed position and QF is in the closed state. As long as TJ is closed, KM+, TJ, TBJ coil, QF, TQ, Z1, and KM- form a path, and the circuit breaker starts to trip. The current in the path drives TBJ to operate, and the normally open contact of TBJ closes to form a holding loop. Even if TJ is disconnected, KM+, TBJ contacts, TBJ coil, QF, TQ, Z1, and KM- still form a path. Once the trip is successful, QF automatically opens, cuts off the path, returns TBJ, and the TBJ contacts are disconnected, and the tripping process is completed.

[0057] Tripping circuit monitoring function: When the circuit breaker is closed, QF is closed, KM+, HWJ coil, QF, TQ, R1, KM- form a path, and HWJ operates; when the path is broken or other abnormalities occur, HWJ returns to achieve monitoring.

[0058] The function of the current limiting and voltage stabilizing module Z1 is to limit the grounding capacitance current when grounding occurs between the TJ and TBJ coils. Only when Z1 is connected to the tripping control circuit:

[0059] Rated voltage of current limiting and voltage stabilizing module Z1 U Z ≤0.5U N When grounding, the instantaneous value of the maximum capacitive current is:

[0060]

[0061] U Z ≥0.5U N When grounding, the instantaneous value of the maximum capacitive current is:

[0062] I C =0

[0063] U Z In 0.4U N ~0.55U N The selection within the range can effectively limit the grounding capacitance current. When the terminal or cable between the TJ and TBJ coils is grounded, the current limiting and voltage stabilizing module Z1 effectively reduces the grounding current flowing through the TBJ coil and TQ, avoiding false tripping.

[0064] When HWJ is working normally, its coil voltage needs to be close to U N , introduce monitoring resistor R1 to trigger the monitoring work of HWJ, so R1 is necessary. R1 is connected in parallel with Z1. When the circuit breaker is closed, QF is closed, KM+, HWJ, QF, TQ, R1, KM- form a path, and the HWJ coil voltage is:

[0065]

[0066] In R1+R TQ Much smaller than R HWJ In this case, it does not affect the normal operation of the HWJ relay.

[0067] Rated voltage U of trip coil TQ TQ Press U N with U Z The difference is selected.

[0068] The recommended parameters are: Z : 0.5U N ; R1+R TQ ≤0.1R HWJ; U TQ : 0.5U N .

[0069] In some implementations, the function achieved by connecting a current limiting and voltage stabilizing module in parallel with a monitoring resistor may also be achieved by connecting multiple sets of current limiting and voltage stabilizing modules in parallel with monitoring resistors and then connecting them in series.

[0070] Figure 4 This is another wiring diagram of a circuit breaker trip control circuit provided in an embodiment of the present application. Figure 4 As shown, the wiring diagram of another circuit breaker tripping control circuit provided in an embodiment of the present application also includes a voltage limiting protection module, which is connected in parallel with the TBJ coil and is used to limit the voltage of the TBJ coil during the tripping process.

[0071] The function of the voltage limiting protection module is to protect the TBJ coil from high voltage. During the tripping process, the voltage in the circuit may rise sharply, and if the TBJ coil is fully borne, it may cause damage to it. Therefore, the voltage limiting protection module is connected in parallel with the TBJ coil to limit the voltage of the TBJ coil during the tripping process. In this way, the TBJ coil can work safely even under high voltage conditions.

[0072] In some implementations, the voltage limiting protection module may include a silicon diode, such as two silicon diodes connected in series to protect a 1.5V coil, and one silicon diode to protect a 0.5V coil.

[0073] According to an exemplary embodiment, the rated voltage of the TBJ coil is 1.5V, the voltage limiting protection module includes two diodes D1 and D2 connected in series, and the anodes of the diodes connected in series are connected to the trip control contact; or,

[0074] The rated voltage of the TBJ coil is 0.5V. The voltage limiting protection module includes a diode, and the anode of the diode is connected to the trip control contact.

[0075] like Figure 4 As shown, another wiring diagram of a circuit breaker trip control circuit provided in an embodiment of the present application also includes an adjustment resistor connected in parallel with the TBJ coil. The rated current of the TBJ coil and the adjustment resistor in parallel is the rated current I of the trip holding circuit. BC , the tripping resistor is used to trip the circuit to maintain the rated current I BC .

[0076] The main function of the adjustment resistor is to provide a variable resistance value. By adjusting this resistance value, the rated current of the trip-holding circuit can be accurately controlled. When the current in the system exceeds the preset trip threshold, the trip-holding relay coil will operate, closing its contacts and starting the tripping process. The adjustment resistor can ensure that the rated current of the trip-holding circuit is always kept within the appropriate range under different working conditions.

[0077] According to an example embodiment, the adjustment resistor includes a basic adjustment resistor connected in parallel with the TBJ coil for setting I BC default value.

[0078] According to an example embodiment, the adjustment resistor further includes a jumper and a preset adjustment resistor; wherein,

[0079] The jumper is connected in series with the preset adjustment resistor and then connected in parallel with the TBJ coil, wherein the jumper is used to switch different preset adjustment resistors, and the preset adjustment resistor is used to adjust the rated current of the TBJ coil according to the switching of the jumper.

[0080] Jumpers and preset trip resistors are used to increase I BC .

[0081] According to an example embodiment, the adjustment resistor includes three series modules consisting of jumpers and preset adjustment resistors: a first series module, a second series module and a third series module; wherein,

[0082] The first series module includes JP1 and R3 connected in series, the second series module includes JP2 and R4 connected in series, and the third series module includes JP3 and R5 connected in series; R3 is equal to R2 and R TBJ The parallel resistance value of R4 is 0.5 times of R3; R5 is 0.5 times of R4.

[0083] Set up three sets of jumpers, preset adjustment resistors in series, and select parameter relationships in a preset manner. 3 Various current values, adjustment is simple and flexible.

[0084] According to an exemplary embodiment, the rated voltage U of Z1 is Z 0.5 times U N ; R1 and R TQ The sum of the resistances is not greater than R HWJ 0.1 times of U TQ 0.5 times U N .

[0085] According to an example embodiment, the current limiting and voltage stabilizing module includes a voltage regulator tube or a transient suppressor having the same rated voltage.

[0086] According to an example embodiment, the other end of the HWJ coil is connected between the TBJ coil and QF; or,

[0087] Connect between TJ and TBJ coils.

[0088] HWJ is connected between the TBJ coil and QF to detect the tripping of TQ. If it is connected between TJ and TBJ coils, the TBJ coil can also be included in the monitoring range. TBJ Much smaller than R TQ , does not affect the normal operation of HWJ.

[0089] exist Figure 4 In the case corresponding to the wiring diagram of another circuit breaker tripping control circuit, the models and parameters of the circuit components are shown in Table 1:

[0090] Table 1: Model, parameters and description of loop components of one embodiment

[0091]

[0092] The circuit breaker trip control circuit of the above embodiment includes: a control power supply KM, a trip control contact TJ, a trip holding relay TBJ, a circuit breaker normally open auxiliary contact QF, a trip coil TQ, and a closing monitoring relay HWJ; it also includes a current limiting and voltage stabilizing module Z1, a monitoring resistor R1, a voltage limiting protection module, and an adjustment resistor;

[0093] One end of TJ is connected to KM+, and the other end is connected to TBJ coil, the other end of TBJ coil is connected to QF, the other end of QF is connected to TQ, the other end of TQ is connected to Z1 cathode, and Z1 anode is connected to KM-; the normally open contact of TBJ is connected in parallel with TJ, R1 is connected in parallel with Z1, one end of HWJ coil is connected to KM+, and the other end is connected to the connection point of TBJ coil and QF.

[0094] Z1 rated voltage U Z Press 0.5U N Select, R1 is 0.1R HWJ -R TQ Selection, TQ rated voltage U TQ Press 0.5U N When the circuit breaker is closed, the HWJ coil voltage is 200.5V and the operation is normal.

[0095] TBJ coil parallel voltage limiting protection module: D1 and D2 are connected in series and then connected in parallel to the TBJ coil, and the anode of D1 and the cathode of D2 are connected to the TBJ coil respectively.

[0096] TBJ coil parallel adjustment resistor: R2 is connected in parallel to the TBJ coil; JP1 is connected in series with R3, JP2 is connected in series with R4, JP3 is connected in series with R5, and all are connected in parallel to the TBJ coil; the parameters are as follows: R3 = R TBJ / / R2, R4=0.5R3, R5=0.5R4 selection, tripping holding circuit rated current I BC The corresponding relationship with the jumper mode is shown in Table 2:

[0097] Table 2: I of a specific embodiment BC Correspondence with jumper mode

[0098] <![CDATA[I BC ]]> 0.5A 1A 1.5A 2A 2.5A 3A 3.5A 4A JP1 disconnect Short Circuit disconnect Short Circuit disconnect Short Circuit disconnect Short Circuit JP2 disconnect disconnect Short Circuit Short Circuit disconnect disconnect Short Circuit Short Circuit JP3 disconnect disconnect disconnect disconnect Short Circuit Short Circuit Short Circuit Short Circuit

[0099] Figure 5 This is a schematic diagram of the principle of another circuit breaker trip control circuit in an embodiment of the present application when the terminal or cable between the trip control contact and the trip holding relay is grounded. Figure 4 , Figure 5 The system was built. When the circuit breaker was closed, the test trip control contact TJ was grounded to the coil of the trip holding relay TBJ. The effectiveness of the specific implementation was checked and compared with the prior art. The test parameters were shown in Table 3 and the test results were shown in Table 4.

[0100] Table 3 Test parameters of an embodiment and prior art

[0101] parameter Prior art 1 Prior Art 2 Specific embodiments <![CDATA[Rated voltage U N > 220V 220V 220V <![CDATA[Trip current I at rated voltage N > 2A 2A 2A <![CDATA[Rated voltage U of trip coil TQ TQ > 220V 220V 110V <![CDATA[Trip coil TQ resistance R TQ > 110Ω 110Ω 55Ω <![CDATA[Rated voltage U of the current limiting and voltage stabilizing module 1 Z > none none 110V Monitoring resistor R1 none none 1.5kΩ <![CDATA[Rated current I of the trip hold circuit BC > 0.5A 1A 0.5A <![CDATA[Trip hold circuit starting current I QD > 0.2A 0.4A 0.2A

[0102] Table 4 Test records of an embodiment and prior art

[0103] Test content Prior art 1 Prior Art 2 Specific embodiments <![CDATA[The instantaneous value I of the maximum capacitive current during grounding C > 1A 1A 0.07A TBJ relay action action action No movement Circuit breaker operation False tripping False tripping No movement

[0104] The test results in Table 3 and Table 4 show that compared with the prior art, the above embodiment effectively limits the grounding capacitance current when the trip control contact and the trip holding relay coil are grounded, thereby preventing the circuit breaker from tripping in error. The adjustment resistor connected in parallel to the trip holding relay coil in the specific embodiment can also increase the rated current of the trip protection circuit, further improving the reliability.

[0105] Figure 6 This is a schematic diagram of local circuit wiring when using a 0.5V trip-holding relay provided in an embodiment of the present application.

[0106] TBJ coil: Model ST2-DC0.5V, coil resistance 1Ω;

[0107] D3: Model P6A10G, forward voltage 0.7V;

[0108] R2: 3Ω;

[0109] R3: 0.75Ω;

[0110] R4: 0.39Ω;

[0111] R5: 0.2Ω.

[0112] Figure 6 The trip holding circuit rated current I BC The corresponding relationship with the jumper mode is shown in Table 5:

[0113] Table 5: I of an embodiment of TBJ using a 0.5V relay BC Correspondence with jumper mode

[0114] <![CDATA[I BC ]]> 1A 2A 3A 4A 5A 6A 7A 8A JP1 disconnect Short Circuit disconnect Short Circuit disconnect Short Circuit disconnect Short Circuit JP2 disconnect disconnect Short Circuit Short Circuit disconnect disconnect Short Circuit Short Circuit JP3 disconnect disconnect disconnect disconnect Short Circuit Short Circuit Short Circuit Short Circuit

[0115] The embodiments of the present application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application. At the same time, changes or deformations made by those skilled in the art based on the ideas of the present application, the specific implementation methods and the scope of application of the present application, all belong to the scope of protection of the present application. In summary, the content of this specification should not be construed as a limitation on the present application.

Claims

1. A circuit breaker trip control circuit, characterized in that: include: Control power supply, trip control contact, trip holding relay coil, trip holding relay normally open contact, circuit breaker normally open auxiliary contact, trip coil, closing monitoring relay coil, current limiting and voltage stabilizing module and monitoring resistor; among them, One end of the trip control contact is connected to the positive electrode of the control power supply, and the other end is connected to the trip holding relay coil, for receiving the circuit breaker trip control signal; The other end of the trip holding relay coil is connected to the normally open auxiliary contact of the circuit breaker for maintaining the tripping action; The other end of the normally open auxiliary contact of the circuit breaker is connected to the trip coil; The other end of the tripping coil is connected to the cathode of the current limiting and voltage stabilizing module, and is used to perform a tripping action according to the circuit breaker tripping control signal; The anode of the current limiting and voltage stabilizing module is connected to the negative electrode of the control power supply, so as to limit the ground current; The normally open contact of the trip holding relay is connected in parallel with the trip control contact; One end of the closing monitoring relay coil is connected to the positive electrode of the control power supply, and the other end is connected between the trip control contact and the normally open auxiliary contact of the circuit breaker, and is used to monitor the execution of the tripping action of the tripping coil; The monitoring resistor is connected in parallel with the current limiting and voltage stabilizing module, and is used to trigger the monitoring action of the closing position monitoring relay coil.

2. The circuit breaker tripping control circuit according to claim 1, characterized in that: It also includes a voltage limiting protection module, which is connected in parallel with the trip holding relay coil and is used to limit the voltage of the trip holding relay coil during the tripping process.

3. The circuit breaker tripping control circuit according to claim 2, characterized in that: The rated voltage of the trip holding relay coil is 1.5V, and the voltage limiting protection module includes two diodes connected in series, and the anodes of the diodes connected in series are connected to the trip control contact; or, The rated voltage of the trip holding relay coil is 0.5V, and the voltage limiting protection module includes a diode, and the anode of the diode is connected to the trip control contact.

4. The circuit breaker tripping control circuit according to claim 1, characterized in that: It also includes an adjusting resistor connected in parallel with the trip-holding relay coil and used for adjusting the rated current of the trip-holding relay coil.

5. The circuit breaker tripping control circuit according to claim 4, characterized in that: The adjustment resistor includes a basic adjustment resistor connected in parallel with the trip-holding relay coil and used for adjusting the rated current of the trip-holding relay coil.

6. The circuit breaker tripping control circuit according to claim 5, characterized in that: The adjustment resistor also includes a jumper and a preset adjustment resistor; wherein, After the jumper is connected in series with the preset adjustment resistor, it is connected in parallel with the trip-holding relay coil, wherein the jumper is used to switch different preset adjustment resistors, and the preset adjustment resistor is used to adjust the rated current of the trip-holding relay coil according to the switching of the jumper.

7. The circuit breaker tripping control circuit according to claim 6, characterized in that: It includes three groups of series modules consisting of the jumper and the preset adjustment resistor: a first series module, a second series module and a third series module; wherein, The first series module includes a first jumper and a first preset adjustment resistor connected in series, the second series module includes a second jumper and a second preset adjustment resistor connected in series, and the third series module includes a third jumper and a third preset adjustment resistor connected in series; The first preset adjustment resistance is equal to the parallel resistance of the basic adjustment resistance and the resistance of the trip holding relay coil; The second preset adjustment resistance is equal to 0.5 times of the first preset adjustment resistance; The third preset adjustment resistance is equal to 0.5 times of the second preset adjustment resistance.

8. The circuit breaker tripping control circuit according to any one of claims 1 to 7, characterized in that: The rated voltage of the current limiting and voltage stabilizing module is 0.5 times the rated voltage of the control power supply; The sum of the resistance of the monitoring resistor and the resistance of the tripping coil is not greater than 0.1 times the resistance of the closing monitoring relay coil; The rated voltage of the trip coil is 0.5 times the rated voltage of the control power supply.

9. The circuit breaker tripping control circuit according to any one of claims 1 to 7, characterized in that: The current limiting and voltage stabilizing module includes a voltage stabilizing tube or a transient suppressor with the same rated voltage.

10. The circuit breaker tripping control circuit according to any one of claims 1 to 7, characterized in that: The other end of the closing monitoring relay coil is connected between the trip holding relay coil and the normally open auxiliary contact of the circuit breaker; or, Connected between the trip control contact and the trip holding relay coil.

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