Intelligent direct-current circuit breaker electronic release

Abstract

The invention discloses an intelligent direct-current circuit breaker electronic release which comprises a self-powered multi-switching-value input acquisition circuit, a double-path redundant current acquisition circuit, a double-path voltage acquisition circuit, a memory circuit, a CAN communication circuit, a control circuit and an output circuit. The control circuit respectively reads information of the self-powered multi-switching-value input acquisition circuit, the dual-path redundant current acquisition circuit, the dual-path voltage acquisition circuit and the memory circuit and then outputs the information to the CAN communication circuit and the output circuit; according to the invention, remote and local opening and closing operations of the circuit breaker can be identified, redundant current can be collected to realize a protection function, the contact state of the circuit breaker can be identified and evaluated, the electrical life times of the circuit breaker can be calculated, and the state of an operating mechanism of the circuit breaker can be judged; according to the invention, intelligent monitoring of the state of the circuit breaker and intelligent control of the circuit breaker are realized, and data support is provided for auxiliary intelligent decision making of the circuit breaker.

Description

Technical Field

[0001] The invention belongs to the technical field of low-voltage DC electrical appliance control, and relates to an intelligent DC circuit breaker electronic release, which is particularly suitable for an intelligent low-voltage DC circuit breaker. Background Art

[0002] A low voltage DC circuit breaker is a protective element used to cut off fault current in a circuit. The electronic release is the control core of the DC circuit breaker, which controls the circuit breaker to achieve various measurement, monitoring and protection functions.

[0003] In the power system, the circuit breaker needs to be opened and closed. At the same time, the contacts of the circuit breaker are consumable parts. After repeated use, they will be burned, affecting the current carrying capacity and breaking capacity of the circuit breaker. The traditional way to judge the state of the circuit breaker contacts is only through visual inspection. For some occasions with high safety requirements, redundant protection functions need to be implemented. The electrical life of the circuit breaker is one of the important parameters of the circuit breaker. In the past, the technology could only view its electrical life value through the mechanical counter of the circuit breaker.

[0004] Therefore, it is necessary to design an intelligent DC circuit breaker electronic release to achieve redundant protection, record the circuit breaker operating status, intelligent monitoring of the circuit breaker contact status, statistical calculation of the circuit breaker electrical life, circuit breaker operating mechanism status detection and data upload, so as to realize auxiliary intelligent decision-making of the circuit breaker. Summary of the invention

[0005] The purpose of the present invention is to provide an intelligent DC circuit breaker electronic release, which, in addition to realizing the redundant protection function, can also collect the opening and closing operation records during the operation of the circuit breaker, analyze and calculate the circuit breaker contact status, and statistically calculate the circuit breaker electrical life, and upload the circuit breaker status information through a high-reliability communication network composed of CAN communication, so as to realize intelligent monitoring and control of the circuit breaker status.

[0006] The technical solution adopted by the present invention to solve the technical problem is: an intelligent DC circuit breaker electronic release, including a control circuit and a self-powered multi-switch input acquisition circuit, a dual-channel redundant current acquisition circuit, a dual-channel voltage acquisition circuit, a memory circuit, a CAN communication circuit and an output circuit respectively connected to the control circuit; the output circuit is connected to the shunt release coil and the pulse release coil of the circuit breaker; the self-powered multi-switch input acquisition circuit acquires dry node status signals including the opening and closing operations before the external distribution board, the local opening and closing operations of the circuit breaker, the circuit breaker status, protection input, etc., and outputs the isolated signals to the control circuit through a photoelectric coupler; the The dual redundant current acquisition circuit acquires the dual redundant current composed of the input pole current and the output pole current of the circuit breaker, and outputs it to the control circuit after signal conditioning; the dual voltage acquisition circuit acquires the input pole voltage and the output pole voltage of the circuit breaker, and outputs it to the control circuit after signal conditioning; the CAN communication circuit is connected to the control circuit through the isolated CAN transceiver module, and transmits the data of the electronic release to the host computer terminal at the same time; the control circuit reads the circuit breaker status, circuit breaker contact status, circuit breaker electrical life times, distribution board operation status, electronic release event and other information stored in the memory circuit, outputs the signal to the output circuit, and outputs the information through the CAN communication circuit.

[0007] The intelligent DC circuit breaker electronic release, wherein the self-powered multi-switch input acquisition circuit comprises a first switch input acquisition circuit, a second switch input acquisition circuit, a third switch input acquisition circuit, a fourth switch input acquisition circuit, a fifth switch input acquisition circuit, a sixth switch input acquisition circuit and a seventh switch input acquisition circuit; the input ends of the first to seventh switch input acquisition circuits are respectively connected to one end of the switch dry node and the negative pole of the power supply, and the other end of the switch dry node is connected to the positive pole of the power supply, thereby forming a loop with the first to seventh switch input acquisition circuits; the first to seventh switch input acquisition circuits are respectively connected to the circuit breaker remote control circuit as the dry node. The opening button and the circuit breaker remote closing button, the two ends of the circuit breaker remote opening button and the circuit breaker remote closing button are respectively connected in series to the power supply VDIO and the input terminals INPUT1+ and INPUT2+; the third switch input acquisition circuit is connected to the circuit breaker local opening button, the fourth switch input acquisition circuit is connected to the circuit breaker local closing button, the fifth switch input acquisition circuit is connected to the circuit breaker auxiliary switch, the sixth switch input acquisition circuit is connected to the circuit breaker protection enable button, the seventh switch input acquisition circuit is connected to the circuit breaker reset operation button, the first switch input acquisition circuit to the seventh switch input acquisition circuit are connected to the control circuit, and the electronic release collects the time from the circuit breaker operation button to the circuit breaker status signal, so as to judge the status of the circuit breaker operating mechanism.

[0008] The intelligent DC circuit breaker electronic release has a dual redundant current acquisition circuit including a main current acquisition circuit connected to the circuit breaker input pole and a redundant current acquisition circuit connected to the circuit breaker output pole; the main current acquisition circuit and the redundant current acquisition circuit acquire current signals, which are input into the control circuit after conditioning; the control circuit converts the conditioned two-way analog signals into digital signals, calculates the actual current value, and performs protection logic operations; when any current signal reaches the protection threshold, the electronic release protection can be triggered, thereby realizing the redundant protection function of the input current channel.

[0009] The intelligent DC circuit breaker electronic release has a dual-channel voltage acquisition circuit including an input pole voltage acquisition circuit connected to the circuit breaker input pole and an output pole voltage acquisition circuit connected to the circuit breaker output pole; the input pole voltage signal and the output pole voltage signal conditioned by the dual-channel voltage acquisition circuit are output to the control circuit, and the control circuit converts the conditioned two-channel analog signals into digital signals, calculates the actual voltage value as input data for voltage protection, and realizes overvoltage protection function and undervoltage protection function.

[0010] The intelligent DC circuit breaker electronic release has a control circuit that calculates the voltage difference between the input pole voltage and the output pole voltage, and divides the collected current value to obtain the circuit breaker contact resistance value. If the circuit breaker contact resistance value exceeds the threshold, it is determined that the circuit breaker contact is worn and needs to be repaired, and the above information is stored in the memory circuit and uploaded to the power system through the CAN communication circuit.

[0011] The output circuit of the intelligent DC circuit breaker electronic release is composed of an electromagnetic relay output circuit based on a mechanical electromagnetic relay K2 and a MOSFET switch output circuit based on a first MOSFET and a second MOSFET of the switch device. The electromagnetic relay output circuit and the MOSFET switch output circuit are connected in parallel and are mutually redundant, which can greatly improve the reliability of the output of the electronic release. The first MOSFET and the second MOSFET are connected in parallel and are mutually redundant to improve the reliability of the output circuit. The electromagnetic relay output circuit uses a first group of output contacts and a second group of output contacts connected in parallel as output devices and connected to the load. The two groups of contacts are mutually redundant to improve the reliability of the output interface. The gate of the first MOSFET is connected in parallel with the gate of the second MOSFET and then connected to the control circuit. The source of the first MOSFET is connected in parallel with the source of the second MOSFET and then connected to one end of the load. The drain of the first MOSFET is connected in parallel with the drain of the second MOSFET and then connected to the negative pole of the power supply. The MOSFET has automatic current sharing capability. The load currents of the first MOSFET and the second MOSFET are the same. When one MOSFET output circuit fails, the other MOSFET output circuit can still work normally.

[0012] Compared with the existing known technologies, the technical solution provided by the present invention has the following significant effects: The present invention designs a self-powered multi-channel switch input acquisition circuit, and records the circuit breaker process operation data, judges the circuit breaker state, and configures the working state of the electronic release through calculation; designs a dual-channel redundant current acquisition circuit, and realizes the redundant current protection function of the circuit breaker through calculation, thereby improving the protection reliability; designs a dual-channel voltage acquisition circuit, and realizes the redundant voltage protection function of the circuit breaker through calculation, thereby improving the protection reliability; realizes the circuit breaker contact state monitoring function by calculating the circuit breaker contact impedance, thereby greatly improving the maintainability of the circuit breaker; and designs a memory circuit to store the circuit breaker operation process data, working state, etc. The invention can store the circuit breaker's operating process data, the circuit breaker's electrical life times, the working status data and the configuration information, realize the intelligent status monitoring of the circuit breaker, and improve the maintainability of the circuit breaker; by designing the memory circuit, the circuit breaker's operating process data, the circuit breaker's electrical life times, the working status data and the configuration information can be stored, and the circuit breaker's intelligent status monitoring can be realized, and the circuit breaker's auxiliary intelligent decision-making can be realized, and the maintainability of the circuit breaker can be improved; by designing the CAN communication circuit and filtering, the robustness and reliability of the CAN communication can be improved; by designing the electromagnetic relay redundant output circuit and the MOSFET parallel redundant output circuit, the reliability of the electronic release protection output can be greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a functional block diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of a self-powered multi-switch input circuit; Figure 3 It is a schematic diagram of a dual-channel redundant current acquisition circuit and a dual-channel voltage acquisition circuit; Figure 4 Set up a schematic diagram for the CAN filter; Figure 5 It is a schematic diagram of the circuit breaker contact state detection algorithm; Figure 6 It is a schematic diagram of redundant current protection algorithm; Figure 7 This is a schematic diagram of the electric operation counting algorithm; Figure 8 This is a schematic diagram of redundant output current of electromagnetic relay; Fig. 9 This is a schematic diagram of the MOSFET redundant output circuit.

[0014] The figures are marked as follows: 1—self-powered multi-switch input acquisition circuit, 2—dual-channel redundant current acquisition circuit, 21—main current, 22—redundant current, 3—dual-channel voltage acquisition circuit, 31—input pole voltage, 32—output pole voltage, 4—memory circuit, 5—CAN communication circuit, 6—control circuit, 7—output circuit, S1—circuit breaker remote opening button, S2—circuit breaker remote closing button. DETAILED DESCRIPTION

[0015] To further illustrate the purpose and technical solution of the present invention, the present invention will be described in further detail below with reference to the specific embodiments of the accompanying drawings.

[0016] Reference Figure 1 As shown, the present invention discloses an intelligent DC circuit breaker electronic release, which is composed of a self-powered multi-switch input acquisition circuit 1, a dual-channel redundant current acquisition circuit 2, a dual-channel voltage acquisition circuit 3, a memory circuit 4, a CAN communication circuit 5, a control circuit 6 and an output circuit 7. The control circuit 6 runs the high-reliability DC circuit breaker electronic release software to realize various intelligent functions. The output circuit 7 is connected to the shunt release coil and the pulse release coil of the circuit breaker. The self-powered multi-switch input acquisition circuit 1 collects dry node status signals including the opening and closing operations before the external distribution board, the local opening and closing operations of the circuit breaker, the circuit breaker status, the protection input, etc., and outputs the isolated signal to the control circuit 6 through the photoelectric coupler. The electronic release collects the time difference from the circuit breaker operation button to the circuit breaker status signal, and compares it with the inherent action time of the circuit breaker operating mechanism to determine the state of the circuit breaker operating mechanism.

[0017] The electronic release of the present invention is designed with a dual redundant current acquisition circuit 2: the signals of the main current 21 and the redundant current 22 are connected to the dual redundant current acquisition circuit 2, which conditions the signals and connects them to the control circuit 6. The control circuit 6 implements the redundant protection function of the electronic release according to the current value of the main current 21 or the redundant current 22, thereby improving the reliability of the protection of the electronic release. Figure 2 The electronic release of the present invention is designed with a dual-path voltage acquisition circuit 3: the input pole voltage 31 and the output pole voltage 32 of the circuit breaker CB1 are connected to the dual-path voltage acquisition circuit 3, and are also connected to the control circuit 6. The control circuit 6 calculates the voltage value of the input pole voltage 31 and the output pole voltage 32 and the voltage difference therebetween, and determines the working state of the circuit breaker contact through the input pole voltage 31 and the output pole voltage 32, thereby realizing intelligent state monitoring of the circuit breaker.

[0018] The memory circuit 4 includes a non-volatile memory device for storing the electronic release configuration file. The memory device is connected to the control circuit 6. The control circuit 6 reads and writes the circuit breaker status, distribution board operation status, electronic release event and other data information stored in the memory circuit 4. When an event occurs in the electronic release, the memory circuit 4 writes the event information to the memory device, and reads the configuration information during the power-on process of the electronic release to realize the corresponding function.

[0019] Reference Figure 2 As shown, the self-powered multi-switch input acquisition circuit 1 includes a first switch input acquisition circuit, a second switch input acquisition circuit, a third switch input acquisition circuit, a fourth switch input acquisition circuit, a fifth switch input acquisition circuit, a sixth switch input acquisition circuit and a seventh switch input acquisition circuit; the input ends of the first switch input acquisition circuit to the seventh switch input acquisition circuit are respectively connected to one end of the switch dry node and the negative pole of the power supply; the switch dry node is connected to the positive pole of the power supply and the other end of the switch dry node, thereby forming a loop with the first switch input acquisition circuit to the seventh switch input acquisition circuit; the first switch input acquisition circuit is connected to the circuit breaker remote opening button S1, and the second switch input acquisition circuit is connected to It is connected to the remote closing button S2 of the circuit breaker, the remote opening button S1 of the circuit breaker, and the remote closing button S2 of the circuit breaker are dry nodes, and the two ends are respectively connected in series to the power supply VDIO and the input terminals INPUT1+ and INPUT2+ of the self-powered multi-switch input acquisition circuit 1; the third switch input acquisition circuit is connected to the local opening button of the circuit breaker, the fourth switch input acquisition circuit is connected to the local closing button of the circuit breaker, the fifth switch input acquisition circuit is connected to the auxiliary switch of the circuit breaker, the sixth switch input acquisition circuit is connected to the circuit breaker protection enable button, the seventh switch input acquisition circuit is connected to the circuit breaker reset operation button, and the first switch input acquisition circuit to the seventh switch input acquisition circuit are connected to the electronic release control circuit 6. The switch input is a dry node and is input in pairs, which can simplify the wiring of the circuit breaker, prevent the input circuit from burning due to the reverse connection condition, and improve the working reliability and maintainability of the self-powered multi-switch input. The electronic release collects the difference between the opening and closing button operation time of the circuit breaker CB1 and the opening and closing time of the circuit breaker, so as to analyze whether the opening and closing mechanism of the circuit breaker works normally and realize the intelligent status monitoring of the circuit breaker. Figure 1 .

[0020] Taking the first switch input acquisition circuit as an example, the first switch input acquisition circuit is used to collect the operation of the remote trip button S1. One end of the remote trip button S1 is connected to the internal power supply VDIO of the electronic release, and the other end is connected to the photocoupler input resistor R135, and the negative input resistor R139 of the photocoupler is connected to the negative pole of the power supply GND_DIO. When the remote trip button S1 is closed, the photocoupler D5 is turned on, INPUT1 changes from a high level to a low level, and INPUT1 is input to the control circuit to realize the remote trip button state acquisition. The internal power supply VDIO is implemented by an isolated power supply to ensure the isolation of the external input and the internal weak current circuit of the electronic release. The second to eighth switch input circuits are implemented in the same way as the first switch input circuit. The self-powered multi-switch input circuit can collect circuit breaker status signals, circuit breaker local opening and closing operation signals, circuit breaker remote opening and closing operation signals, etc., to realize intelligent monitoring of the circuit breaker operation status and provide data support for auxiliary intelligent decision-making of the circuit breaker.

[0021] The electronic release collects the time when the circuit breaker closing button is pressed and the time when the circuit breaker is in the closed state, and calculates the time difference between the two times to obtain the closing action time of the circuit breaker operating mechanism; the electronic release collects the time when the circuit breaker opening button is pressed and the time when the circuit breaker is in the open state, and calculates the time difference between the two times to obtain the opening action time of the circuit breaker operating mechanism. By comparing the above time with the inherent action time of the circuit breaker, the state information of the circuit breaker operating mechanism can be determined, and the intelligent detection and judgment of the state of the circuit breaker operating mechanism can be realized, providing data support for the preventive maintenance of the circuit breaker.

[0022] The dual redundant current acquisition circuit 2 acquires the dual redundant current composed of the input terminal current and the output terminal current of the circuit breaker input pole, and outputs the signal to the control circuit 6 after signal conditioning. Figure 3 As shown, the dual-channel redundant current acquisition circuit 2 includes a main current acquisition circuit connected to the input pole of the circuit breaker and a redundant current acquisition circuit connected to the output pole of the circuit breaker; the main current acquisition circuit and the redundant current acquisition circuit acquire current signals, which are input into the control circuit 6 after conditioning, and the control circuit 6 converts the two conditioned analog signals into digital signals, calculates the actual current value, and performs protection logic operations. When any current signal reaches the protection threshold, the electronic release protection can be triggered to realize the redundant protection function of the input current channel. The main current 21 of the circuit breaker input pole current is collected from the input pole of the circuit breaker CB1, conditioned by the dual-channel redundant current acquisition circuit 2, and input into the control circuit; the redundant current 22 is collected from the output pole of the circuit breaker CB1, conditioned by the dual-channel redundant current acquisition circuit 2, and input into the control circuit.

[0023] The dual-channel voltage acquisition circuit 3 acquires the input pole voltage and the output pole voltage of the circuit breaker, and outputs the signal to the control circuit 6 after signal conditioning. Figure 3 As shown, the dual-channel voltage acquisition circuit 3 includes an input pole voltage acquisition circuit connected to the input pole of the circuit breaker and an output pole voltage acquisition circuit connected to the output pole of the circuit breaker; the input pole voltage signal and the output pole voltage signal conditioned by the dual-channel voltage acquisition circuit 3 are output to the control circuit 6, and the control circuit 6 converts the conditioned two-channel analog signals into digital signals, calculates the actual voltage value, and uses it as input data for voltage protection to realize overvoltage protection function and undervoltage protection function. The circuit breaker input pole voltage 31 is collected from the input pole of the circuit breaker CB1, conditioned by the dual-channel voltage acquisition channel 3, and input to the control circuit; the output pole voltage 32 is collected from the output pole of the circuit breaker CB1, conditioned by the dual-channel voltage acquisition channel 3, and input to the control circuit.

[0024] The control circuit 6 calculates the voltage difference between the input pole voltage and the output pole voltage, and divides the collected current value to obtain the circuit breaker contact resistance value. If the circuit breaker contact resistance value exceeds the threshold, it is determined that the circuit breaker contact is worn and needs to be repaired, and the above information is stored in the memory circuit 4 and uploaded to the power system through the CAN communication circuit 5. The control circuit 6 collects the state of the self-powered multi-switch input circuit, collects the signal of the dual-channel redundant current collection circuit, collects the signal of the dual-channel voltage collection circuit, and calculates and processes the above information to realize the circuit breaker state judgment, protection function, contact state judgment function and electric operation counting function of the electronic release, and controls the output circuit to control the circuit breaker to disconnect.

[0025] The control steps of the control circuit 6 refer to Figure 5 , Figure 6 , Figure 7 shown. Figure 5 This is the step for judging the state of the circuit breaker contact. The contact resistance of the circuit breaker is R CB When the circuit breaker is connected to a current I, the voltages at the input and output poles of the circuit breaker are U IN and U OUT . When (U IN -U OUT ) / I>R CB , it can be determined that the circuit breaker contact state is abnormal, and the electronic release issues an abnormal circuit breaker contact state alarm, realizing intelligent monitoring of the circuit breaker contact state.

[0026] The control circuit 6 reads the circuit breaker status, distribution board operation status, electronic release event and other information stored in the memory circuit 4, and outputs the signal to the output circuit 7; the control circuit 6 reads the signal of the CAN communication circuit 5, outputs the signal to the output circuit 7, and the control circuit 6 controls the output circuit 7 to output; the control circuit 6 designs a hardware filtering method to filter out useless data frames, ensures that the electronic release only receives useful data frames, reduces the computing burden of the microcontroller in the controller, ensures the reliability of CAN communication, and provides data support for the circuit breaker auxiliary intelligent decision-making.

[0027] When an event occurs in the electronic release, the control circuit 6 writes the event information to the storage device, and the configuration file of the electronic release is also stored in the storage device. During the power-on process of the electronic release, the configuration information is read to realize the corresponding function; the CAN communication circuit 5 mainly includes a CAN interface device, and the CAN communication circuit 5 is connected to the control circuit 6 through the CAN interface device, and the data of the electronic release is transmitted to the host computer terminal at the same time. The CAN communication steps refer to Figure 4 shown.

[0028] Redundancy protection steps are shown in Figure 6 .exist Figure 6 Both the main current and the redundant current can be used for the input of the electronic release protection algorithm. After the protection is output, the control circuit 6 collects the circuit breaker status and the circuit breaker input pole current and output pole current through the self-powered multi-switch input circuit. If the circuit breaker position status has not changed or the circuit breaker input pole current or the circuit breaker output pole current is still not 0, it is judged that the circuit breaker has failed, and the electronic release sends a circuit breaker failure alarm to realize the intelligent monitoring of the circuit breaker contact status.

[0029] The steps for counting the electrical life of the circuit breaker are shown in Figure 7 The electronic release collects current I through a dual redundant current collection circuit 2. When the current I is greater than a certain set threshold value Ir of the circuit breaker and the circuit breaker state CBstate changes from closed to open, the number of times the circuit breaker's electrical life is judged to be increased by 1; if the current I is less than a certain set threshold value Ir of the circuit breaker and the circuit breaker state CBstate changes from closed to open, the number of times the circuit breaker's mechanical life is judged to be increased by 1, thereby realizing intelligent monitoring of the circuit breaker's electrical life.

[0030] Reference Figure 8 , Fig. 9As shown, the output circuit 7 includes an electromagnetic relay output circuit and a MOSFET switch output circuit; the electromagnetic relay output circuit uses a double-group contact relay as an output device. The electromagnetic relay includes a first group of output contacts and a second group of output contacts. The first group of output contacts is connected in parallel with the second group of output contacts and connected to the load to improve the reliability of the output interface; the MOSFET switch output circuit mainly includes a first MOSFET and a second MOSFET as switch devices. The gate of the first MOSFET is connected in parallel with the gate of the second MOSFET and connected to the control circuit 6. The source of the first MOSFET is connected in parallel with the source of the second MOSFET and connected to one end of the load. The drain of the first MOSFET is connected in parallel with the drain of the second MOSFET and connected to the negative pole of the power supply. MOSFET has automatic current sharing capability, and the load current of the first MOSFET and the second MOSFET is the same. When one MOSFET output circuit fails, the other MOSFET output circuit can still work normally. The first group of output contacts is connected in parallel with the second group of output contacts, the first MOSFET is connected in parallel with the second MOSFET, and the electromagnetic relay output circuit is connected in parallel with the MOSFET switch output circuit, which can greatly improve the reliability of the output of the electronic release. The output circuit is composed of a mechanical electromagnetic relay K2 and a MOSFET switch output circuit. The two sets of contacts of the electromagnetic relay are mutually redundant, and the MOSFET switch output circuit is mutually redundant by two MOSFETs in parallel, and the electromagnetic relay and MOSFET switch output circuits are mutually redundant, thereby improving the reliability of the output circuit. The output circuit 7 includes a dual-set contact parallel electromagnetic relay and a dual MOSFET parallel output circuit 7, which is used to improve the output reliability of the electronic release.

[0031] When the control circuit 6 runs the protection algorithm to output the protection signal, it outputs the OPEN signal and the PULSE signal at the same time. Figure 8 As shown. The electromagnetic relay K2 has two groups of normally open contacts. When the relay is applied with the drive signal OPEN, the first group of contacts 3, 5 and the second group of contacts 6, 7 of the relay are turned on at the same time. The first group of contacts and the second group of contacts are redundant with each other, which improves the reliability of the output. The MOSFET output redundant circuit is shown in FIG. Fig. 9 As shown. In the figure, Q1 and Q2 are output MOSFETs, V1 is an anti-parallel diode, LOAD is the load, that is, the circuit breaker pulse release coil. PAULSE is the MOSFET drive signal. When the control circuit outputs the PAULSE signal, MOSFETQ1 and Q2 are turned on at the same time, and the protection output is effective. Due to the automatic current sharing characteristics of MOSFET, the load current can pass through Q1 and Q2 evenly, effectively extending the service life of Q1 and Q2. Q1 and Q2 are mutually redundant. At the same time, relay K2 and Q1, Q2 are mutually redundant.

[0032] The electronic release of the circuit breaker of the present invention can intelligently collect information such as the contact status, electrical life and operating status of the circuit breaker, and realize intelligent control of the circuit breaker, while providing data support for auxiliary intelligent decision-making of the circuit breaker.

[0033] By collecting the input and output pole voltages, the circuit breaker contact voltage drop is determined, and then the circuit breaker contact status is determined; the circuit breaker operation record and the number of circuit breaker electrical life operations can be identified and stored, and the above information is stored and transmitted to the host computer through CAN communication. At the same time, the protection reliability of the electronic release is improved through the redundancy of current acquisition channels, relay contact redundancy and MOSFET parallel output, which is suitable for DC circuit breakers and power systems with high reliability requirements.

[0034] The specific embodiments described herein are only for illustration of the principles and specific implementation methods of the present invention. A person skilled in the art of the present invention may make various modifications or supplements to the specific embodiments described or replace them in a similar manner, but they will not deviate from the principles, topology or exceed the scope defined by the appended claims.

Claims

1. An intelligent DC circuit breaker electronic release, characterized in that: The invention comprises a control circuit (6) and a self-powered multi-switch input acquisition circuit (1), a dual-channel redundant current acquisition circuit (2), a dual-channel voltage acquisition circuit (3), a memory circuit (4), a CAN communication circuit (5) and an output circuit (7) respectively connected to the control circuit (6); the output circuit (7) is connected to the shunt release coil and the pulse release coil of the circuit breaker; the self-powered multi-switch input acquisition circuit (1) acquires dry node status signals including the opening and closing operation before the external distribution board, the local opening and closing operation of the circuit breaker, the circuit breaker status, and the protection input, and outputs them to the control circuit (6); the dual-channel redundant current acquisition circuit ( 2) collecting the dual redundant current composed of the circuit breaker input pole current and the output pole current, and outputting the signal to the control circuit (6) after signal conditioning; the dual voltage collection circuit (3) collecting the circuit breaker input pole voltage and the output pole voltage, and outputting the signal to the control circuit (6) after signal conditioning; the CAN communication circuit (5) is connected to the control circuit (6) via the isolated CAN transceiver module, and transmits the data to the upper computer terminal; the control circuit (6) reads the circuit breaker information stored in the memory circuit (4) and the signal of the CAN communication circuit (5), outputs the signal to the output circuit (7), and outputs the circuit breaker status information via the CAN communication circuit (5).

2. The intelligent DC circuit breaker electronic release according to claim 1, characterized in that: The self-powered multi-switch input acquisition circuit (1) comprises a first switch input acquisition circuit, a second switch input acquisition circuit, a third switch input acquisition circuit, a fourth switch input acquisition circuit, a fifth switch input acquisition circuit, a sixth switch input acquisition circuit and a seventh switch input acquisition circuit; The input ends of the first to seventh switch quantity input acquisition circuits are respectively connected to one end of the switch quantity dry node and the negative pole of the power supply, and the other end of the switch quantity dry node is connected to the positive pole of the power supply to form a loop; the first to second switch quantity input acquisition circuits are respectively connected to the circuit breaker remote opening button (S1) and the circuit breaker remote closing button (S2) as dry nodes, and the two ends of the circuit breaker remote opening button (S1) and the circuit breaker remote closing button (S2) are respectively connected in series to the power supply VDIO and the input ends INPUT1+ and INPUT2+; the third switch quantity input acquisition circuit is connected to the circuit breaker local opening button, the fourth switch quantity input acquisition circuit is connected to the circuit breaker local closing button, the fifth switch quantity input acquisition circuit is connected to the circuit breaker auxiliary switch, the sixth switch quantity input acquisition circuit is connected to the circuit breaker protection enable button, the seventh switch quantity input acquisition circuit is connected to the circuit breaker reset operation button, and the first to seventh switch quantity input acquisition circuits are connected to the control circuit (6).

3. An intelligent DC circuit breaker electronic release according to claim 1 or 2, characterized in that: The dual-channel redundant current acquisition circuit (2) comprises a main current acquisition circuit connected to the input pole of the circuit breaker and a redundant current acquisition circuit connected to the output pole of the circuit breaker; The main current collection circuit and the redundant current collection circuit collect current signals, which are input into the control circuit (6) after conditioning. The control circuit (6) converts the two analog signals into digital signals, calculates the actual current value, and performs protection logic operations. When any current signal reaches the protection threshold, the electronic release protection is triggered, thereby realizing redundant protection of the input current channel.

4. The intelligent DC circuit breaker electronic release according to claim 3, characterized in that: The dual-path voltage acquisition circuit (3) comprises an input pole voltage acquisition circuit connected to the input pole of the circuit breaker and an output pole voltage acquisition circuit connected to the output pole of the circuit breaker; the input pole voltage signal and the output pole voltage signal conditioned by the dual-path voltage acquisition circuit (3) are output to the control circuit (6); the control circuit (6) converts the two-path analog signals into digital signals, calculates the actual voltage value as input data for voltage protection, and implements overvoltage protection and undervoltage protection.

5. The intelligent DC circuit breaker electronic release according to claim 4, characterized in that: The control circuit (6) calculates the voltage difference between the input pole voltage and the output pole voltage, and divides the collected current value to obtain the circuit breaker contact resistance value. If the circuit breaker contact resistance value exceeds a threshold value, it is determined that the circuit breaker contact is worn and needs to be repaired. The information is stored in the memory circuit (4) and uploaded to the power system through the CAN communication circuit (5).

6. The intelligent DC circuit breaker electronic release according to claim 4, characterized in that: The output circuit (7) is composed of an electromagnetic relay output circuit based on a mechanical electromagnetic relay K2 and a MOSFET switch output circuit based on a first MOSFET and a second MOSFET. The electromagnetic relay output circuit is connected in parallel with the MOSFET switch output circuit, the first MOSFET is connected in parallel with the second MOSFET, and the electromagnetic relay output circuit uses a first group of output contacts and a second group of output contacts connected in parallel as output devices and connected to a load. The gate of the first MOSFET is connected in parallel with the gate of the second MOSFET and then connected to the control circuit (6), the source of the first MOSFET is connected in parallel with the source of the second MOSFET and then connected to one end of the load, the drain of the first MOSFET is connected in parallel with the drain of the second MOSFET and then connected to the negative pole of the power supply, and the load currents of the first MOSFET and the second MOSFET are the same.

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