A new soft-start intelligent high-voltage direct-current contactor

Abstract

The application discloses a novel soft-start intelligent high-voltage direct-current contactor, which comprises a high-voltage direct-current contactor and an intelligent control module; the intelligent control module comprises a processor, a CAN communication circuit, an optical MOS driving circuit, a soft-start circuit, a voltage and current acquisition circuit and a protection post self-locking circuit. The processor controls the soft-start circuit to first connect a bypass loop to charge a load end capacitor, and after a time delay, controls main contact attraction through the optical MOS driving circuit to avoid current peak damage to the contact; a Hall sensor is nested in the main contact to realize large-current non-contact acquisition; I 2 T inverse time overcurrent protection and short-circuit protection are performed, protection parameters are modified online, and after protection, the self-locking circuit is self-locked through hardware, and CAN is reset and removed; working states and health information are reported in real time. The split structure is adopted, the integrated degree is high, the volume is small, the adaptability is strong, and full-function intelligent control of the high-voltage direct-current contactor is realized.

Description

Technical Field

[0001] This invention relates to the field of DC high voltage components, and in particular to a novel soft-start intelligent high voltage DC contactor. Background Technology

[0002] In aircraft power distribution systems, high-voltage DC contactors are key actuators for distributing power to high-power loads. Traditional high-voltage DC contactors mainly consist of a contact assembly and an electromagnet assembly. The contact assembly relies on the magnetic field generated by the switching on and off of the electromagnet assembly to move the armature, thereby opening and closing the contacts. However, traditional contactors lack current sensing, status monitoring, and intelligent protection functions. In practical applications, they require external control circuits, protection devices, and communication modules to achieve complete power distribution control functions. This results in high complexity of the main control circuit, difficulty in troubleshooting, and poor maintainability.

[0003] To achieve complete power distribution control functions of a contactor, CN112786363A discloses a DC contactor with intelligent protection function. Its technical solution includes: a contact current detection sensing module, an MCU module, a MOSFET switching circuit, a remote communication module, and a voltage regulator module. This prior art uses a current sensor to collect the contact current. When the preset trip current value is reached, the MCU controls the drive circuit to disconnect the contactor contacts, achieving trip protection, and provides alarm information through the remote communication module (CAN bus). However, its protection method is only fixed threshold trip protection; that is, when the current reaches the preset trip value, the contact disconnection operation is immediately performed, lacking I / O protection. 2 The inverse-time current protection function cannot establish a dynamic matching relationship between the overcurrent level and the protection action time. It cannot achieve delayed protection for minor overcurrent conditions to balance system continuity and safety. Although the trip protection threshold can be set via DIP switch or remote communication, it does not support online modification of the inverse-time current protection characteristic curve, and cannot flexibly configure protection strategies according to different load characteristics. Furthermore, the solution does not have a soft-start circuit. When a capacitive load is connected, a large current spike directly impacts the main contacts, reducing the contact life. Fourth, the solution does not have a self-locking function after protection. After a fault protection, the main contacts may be mistakenly reconnected, posing a safety hazard.

[0004] For example, CN116047157A discloses a unified high-voltage DC intelligent contactor and method based on isolated current detection. Its technical solution includes: an intelligent contactor control module (including a CPU minimum system, power processing circuit, current sampling and conditioning circuit, CAN communication circuit, and machine position code recognition circuit, etc.), employing a shunt-based isolated current sampling scheme (isolation operational amplifier + shunt), and realizing I / O detection for different load specifications through machine position code recognition. 2 The T-overcurrent protection curve can be selected online in a programmable manner.

[0005] Although this scheme has I 2 While it features overcurrent protection, its current sampling still employs a shunt design, with the shunt integrated into the busbar. For high current detection exceeding 300A, the shunt's heat generation and power consumption remain significant issues. Furthermore, the design lacks a self-locking circuit after protection. After overvoltage, overload, or short-circuit protection occurs and the main contacts open, there is a lack of hardware-level self-locking mechanisms to ensure that the main contacts remain open until a new control command is received.

[0006] Therefore, existing technologies lack soft-start designs for high-voltage DC high-current scenarios, failing to effectively suppress current spikes at the moment of capacitive load switching; they lack reliable hardware self-locking mechanisms after protection; current detection schemes have limitations in terms of power consumption, size, or accuracy; and the configurability of protection parameters and the real-time performance of communication need to be improved. Therefore, it is necessary to invent a new type of intelligent high-voltage DC contactor that integrates soft-start, intelligent protection, status monitoring, and CAN communication functions. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by providing a novel soft-start intelligent high-voltage DC contactor. This is achieved through a separate integrated design of the intelligent control module and the high-voltage DC contactor, employing Hall sensor high-current acquisition technology, optical MOS drive technology, bypass switching soft-start technology, and I... 2 The T-reverse time-limited current protection technology and the hardware self-locking technology after protection enable full-function intelligent control of the high-voltage DC contactor.

[0008] The technical solution of the present invention: A novel soft-start intelligent high-voltage DC contactor includes a high-voltage DC contactor and an intelligent control module. The high-voltage DC contactor includes main contacts, a contactor coil, and auxiliary contacts; the intelligent control module includes a processor, a CAN communication circuit, an optical MOS drive circuit, a soft-start circuit, a voltage and current acquisition circuit, and a protection self-locking circuit.

[0009] The processor is connected to the CAN communication circuit, the optical MOS drive circuit, the soft-start circuit, the voltage and current acquisition circuit, and the protection self-locking circuit to form an intelligent control architecture. The processor receives control commands through the CAN communication circuit, and the intelligent control module can achieve redundancy control through I / O and the CAN bus. That is, when the CAN bus communication fails, it can switch to direct I / O control, or achieve cross-verification of control commands through dual channels of I / O and CAN bus, thereby improving the reliability of the system.

[0010] The opto-MOS drive circuit includes an opto-MOS. The front end of the opto-MOS is connected to a 5V power supply and its on / off state is controlled by the processor. The rear end is connected to the contactor coil and is powered by an isolated 28V power supply. The opto-MOS integrates a light-emitting diode (LED) and a photoMOSFET. When the processor outputs a high-level signal, the LED conducts and emits light, and the photoMOSFET receives the light signal and conducts, thus applying the isolated 28V power supply to the two ends of the contactor coil, generating electromagnetic attraction to drive the main contacts to close. When the processor outputs a low-level signal or a protection action is activated, the LED turns off, the photoMOSFET turns off, the contactor coil is de-energized, and the main contacts open under spring force. This opto-MOS drive scheme utilizes the principle of opto-isolation to achieve electrical isolation between the control side (5V low voltage) and the power side (28V isolated power supply). This ensures both a fast response time (microsecond level) for the control signal and complete isolation between the high and low voltage sides, avoiding electromagnetic interference from the power circuit to the control circuit. Simultaneously, the driving capability of the opto-MOS can meet the high-current starting requirements of the contactor coil.

[0011] The current sensor in the voltage and current acquisition circuit uses a Hall sensor. By modifying the main contact structure, the Hall sensor is nested within the main contact to acquire the current value of the main contact and output it to the intelligent control module in analog form. When current flows through the main contact, a magnetic field is applied perpendicularly to the Hall element, generating a Hall voltage proportional to the current across the element. By measuring this Hall voltage, the current value of the main contact can be indirectly obtained. Since the Hall sensor is a non-contact measurement method, it eliminates the need for a series shunt, avoiding the heat generation and power consumption problems of the shunt under high current. Furthermore, the design of the Hall sensor nested within the main contact structure significantly reduces the size and weight of the power distribution product, making it particularly suitable for applications in the aerospace industry with stringent weight reduction requirements. After the acquired current value is transmitted to the processor via analog signal, the processor executes I / O based on this current value. 2 T-overcurrent protection and short-circuit protection functions.

[0012] The soft-start circuit is equipped with a soft-start current-limiting resistor interface, through which a bypass circuit is connected. When the processor receives the turn-on command, it first controls the soft-start circuit to connect the bypass circuit. The current-limiting resistor in the bypass circuit limits the charging current, allowing the load capacitor to charge slowly through the current-limiting resistor. After a set delay, the load capacitor voltage rises to near the power supply voltage. At this time, the processor controls the optical MOS drive circuit to turn on the contactor coil, and the main contacts close, switching to the main circuit. This soft-start method is fundamentally different from the soft-start method that controls the IGBT duty cycle through PWM: the soft-start of this invention is achieved through the timing control of bypass current-limiting charging and main circuit switching. The switching time is only tens of milliseconds, much shorter than the 3-10 seconds of the PWM method, making it more suitable for the rapid response requirements of aviation power distribution systems. At the same time, since the main contacts have not yet closed during the bypass charging stage, the current spike is suppressed by the current-limiting resistor, avoiding the arc erosion and mechanical impact of the large current spike at the moment of turn-on on, effectively improving the electrical and mechanical life of the main contacts.

[0013] The processor executes I based on the acquired main contact current value. 2 The system includes overcurrent and short-circuit protection functions, and performs overvoltage protection and undervoltage warning functions based on the collected voltage values. When the main contact current exceeds the set starting protection point, the processor calculates the protection action time according to the inverse time characteristic curve based on the current value. The larger the current, the shorter the action time, i.e., I... 2 T=K (K is a constant), this protection characteristic matches the thermal withstand capability curve of the protected equipment (such as cables and motors), effectively protecting the equipment while avoiding unnecessary frequent tripping. Short-circuit protection operates immediately when the current reaches the short-circuit protection point, without delay. Overvoltage protection disconnects contacts when the load voltage exceeds the set voltage protection point, and undervoltage warning sends a warning message when the voltage falls below the undervoltage point.

[0014] The starting protection point and inverse-time current protection characteristic curve of the overcurrent protection function can be modified online via the CAN communication circuit. The processor stores the protection parameters in non-volatile memory, and the host computer sends parameter modification commands via the CAN bus. After parsing the commands, the processor updates the protection threshold and characteristic curve coefficients. This allows for adaptation to different load protection requirements without hardware changes, greatly improving the product's adaptability and flexibility.

[0015] In the event of overvoltage, overload, or short circuit, the self-locking circuit locks itself after the main contacts open, ensuring they remain open until a new control command is received. The self-locking is released when a reset command is received via the CAN communication circuit. The self-locking circuit consists of a hardware latch. When the processor determines that a protection action is needed, it controls the opto-MOS to turn off, opening the main contacts, and simultaneously outputs a latch signal to the self-locking circuit. The self-locking circuit latches this state and feeds it back to the processor input, keeping the processor in a protected state. Even after the fault disappears, the main contacts will not automatically re-engage, ensuring that the self-locking is only released after the operator sends a reset command via the CAN bus. Compared to pure software self-locking, this hardware self-locking mechanism offers higher reliability, is unaffected by software malfunctions or electromagnetic interference, and effectively avoids the risk of accidental reconnection after a fault protection event.

[0016] The auxiliary contact collects the number of times the main contact engages and reports the contactor's health status to the processor via a health monitoring module. The auxiliary contact is mechanically linked to the main contact; it operates synchronously each time the main contact engages / disengages. The processor records and stores the engagement count and assesses the contactor's remaining lifespan and health status by analyzing parameters such as the engagement count and contact resistance trends. Simultaneously, the processor reports the contactor's operating status, current and voltage values, and contact engagement count in real time via a CAN communication circuit. The host computer can monitor the contactor's operation in real time and issue commands to query or configure parameters when needed, achieving full lifecycle health management of the contactor.

[0017] The intelligent control module and the high-voltage DC contactor adopt a split structure design and are fixed with screws. A shielding alloy is installed between the high-voltage DC contactor and the intelligent control module. This structural design allows the intelligent control module to be adapted to contactors with different rated loads, improving versatility; the split design also facilitates individual replacement and repair in case of failure, reducing maintenance costs. The shielding alloy effectively isolates the electromagnetic interference generated by the contactor power circuit from the control module, ensuring the stable operation of the processor and communication circuit.

[0018] The beneficial effects of this invention are: (1) By using bypass switching soft start technology, when the capacitive load is connected, the capacitor at the load end is first charged through the current limiting resistor, and then switched to the main circuit after tens of milliseconds. This effectively suppresses the current spike at the moment of connection, avoids arc erosion and mechanical impact on the main contacts, and significantly improves the electrical and mechanical life of the main contacts. (2) The non-contact high current detection scheme with Hall sensor nested main contact avoids the heat generation and power consumption problems of the shunt scheme, reduces the product size and weight, meets the strict requirements of the aviation field for weight reduction, and realizes high current wide range high precision acquisition. (3) Using I2 T-inverse-time current protection technology matches the protection characteristics with the thermal withstand capability curve of the protected equipment, which can effectively protect the equipment and avoid unnecessary frequent tripping. Moreover, the starting protection point and inverse-time characteristic curve can be modified online via CAN bus, which can adapt to different loads without changing the hardware, greatly improving the adaptability and flexibility of the product. (4) The hardware protection self-locking circuit is adopted. After the main contacts are opened after overvoltage, overload or short circuit protection, the hardware self-locking is performed to ensure that the main contacts remain open before there is a new control command. This effectively avoids the risk of false reconnection after fault protection and improves system safety. (5) The opto-MOS driving technology is used to achieve opto-isolation between the control side and the power side, which avoids electromagnetic interference from the power circuit to the control circuit, ensures fast response and reliability of the control, and supports I / O and CAN bus redundancy control, which improves the fault tolerance of the system. (6) The working status, current and voltage values ​​and contact engagement times are reported in real time through the CAN communication circuit, and online parameter configuration and remote control are supported, realizing intelligent management of the entire life cycle of the contactor. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the structural principle of the present invention.

[0020] Figure 2 This is a schematic diagram of the optical MOS wiring structure of the present invention.

[0021] Figure 3 This is a schematic diagram illustrating the soft-start principle of the present invention.

[0022] Figure 4 This is a schematic diagram of the internal structure of the contactor of the present invention.

[0023] Figure 5 This is a schematic diagram of the outer shell structure of the present invention.

[0024] In the diagram: 1-Main contact, 2-Electrical connector, 3-Intelligent control module, 4-Shielding alloy, 5-Soft start current limiting resistor interface, 6-Current sensor, 7-Contactor coil. Detailed Implementation

[0025] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, so that the technical solutions and advantages of the present invention become clearer. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and should not be used to limit the scope of protection of the present invention.

[0026] Example 1: As Figure 1As shown, the novel soft-start intelligent high-voltage DC contactor of the present invention comprises two main parts: a high-voltage DC contactor and an intelligent control module, adopting a split-type structural design. The high-voltage DC contactor includes main contacts, a contactor coil, and auxiliary contacts; the intelligent control module includes a processor, a CAN communication circuit, an optical MOS drive circuit, a soft-start circuit, a voltage and current acquisition circuit, and a protection self-locking circuit.

[0027] The high-voltage DC contactor has a rated current carrying capacity of 270Vd.c. and 300A. The main contacts are made of silver alloy, providing excellent conductivity and resistance to arc erosion. The contactor coil uses DC excitation, with a rated operating voltage of 28V, a coil resistance of approximately 60Ω, a pulling power of approximately 13W, and a holding power of approximately 3W. The auxiliary contacts are mechanically linked to the main contacts, used to indicate the pulling / opening status of the main contacts and record the number of pulls.

[0028] The intelligent control module is based on a 32-bit ARM Cortex-M series processor with a main frequency of 72MHz. It has 128KB Flash and 20KB SRAM, and features multiple 12-bit AD sampling channels, multiple timers, a CAN controller, and abundant GPIO resources. The intelligent control module is connected to a high-voltage DC contactor via an electrical connector. The electrical connector uses an aerospace-grade rectangular connector with reliable mechanical locking and anti-mismating functions.

[0029] A shielding alloy is installed between the intelligent control module and the high-voltage DC contactor. The shielding alloy is made of permalloy, which has high magnetic permeability and low coercivity, effectively absorbing and attenuating electromagnetic interference generated by the contactor's power circuit, protecting the sensitive electronic components in the control module for normal operation. The shielding alloy is fixed to the mating surface between the contactor housing and the intelligent control module housing with screws, forming a continuous magnetic shielding path.

[0030] Example 2: like Figure 2 As shown, the optical MOS driving circuit includes an optical MOS. The front end of the optical MOS is connected to a 5V power supply and is controlled by the processor GPIO for switching on and off. The rear end is connected to a contactor coil and is powered by an isolated 28V power supply.

[0031] The specific connection method is as follows: the anode of the light-emitting diode inside the optical MOS is connected to a 5V power supply through a current-limiting resistor, and the cathode is connected to the GPIO output pin of the processor; the drain of the photosensitive MOSFET inside the optical MOS is connected to the positive terminal of the isolated 28V power supply, one end of the source contactor coil is connected to the negative terminal of the isolated 28V power supply.

[0032] When the processor receives the connection command and determines that the circuit status is normal, the GPIO outputs a low level to the photoMOSFET cathode, turning on the LED and emitting light. Under light illumination, the photoMOSFET channel conducts, applying the 28V isolation power supply to the two ends of the contactor coil. The coil generates electromagnetic force, driving the armature to move and closing the main contacts. When the processor determines that disconnection is necessary, the GPIO outputs a high level, turning off the LED, turning off the photoMOSFET, de-energizing the coil, and causing the main contacts to open under the action of the return spring.

[0033] The typical response time of the opto-MOSFET is 0.5ms, much faster than the 10ms or more of a mechanical relay, meeting the requirements for rapid control. The opto-MOSFET's isolation withstand voltage reaches 2500Vrms, ensuring electrical safety between the 5V low-voltage control side and the 28V isolated power supply on the power side. Furthermore, a freewheeling diode is connected in parallel across the contactor coil to absorb the reverse induced electromotive force generated when the coil is de-energized, protecting the opto-MOSFET from overvoltage damage.

[0034] Example 3: Hall Sensor Current Acquisition Circuit The current sensor in the voltage and current acquisition circuit uses a Hall sensor. By modifying the structure of the main contacts, the Hall sensor is nested on the conductive rod of the main contacts. Specifically, the conductive rod of the main contacts adopts a hollow or slotted design, and the Hall sensor is installed in the gap of the conductive rod. When current flows through the conductive rod, a magnetic field proportional to the current is generated at the sensor position. The Hall element detects this magnetic field and outputs a voltage signal proportional to the current.

[0035] The Hall sensor employs a closed-loop Hall effect current sensor with a measurement range of 0-800A, an output sensitivity of 2.5mV / A, a zero-point output of 0.5V, and a full-scale output of 4.5V. The sensor output signal is fed into an AD acquisition chip after being low-pass filtered by an RC filter. The chip has a 16-bit resolution and a sampling rate of 1MHz. After analog-to-digital conversion, the signal is transmitted to the main control processor via communication for processing. The processor performs digital filtering on the acquired current value before using it for protection judgment and reporting.

[0036] Since the Hall sensor is a non-contact measurement device, it does not require a shunt in series with the main circuit, thus avoiding the It of the shunt at a rated current of 300A. 2 The design addresses power consumption (4.5W at 300A with a 50μΩ shunt) and heat generation issues. Meanwhile, the Hall sensor's nested design on the main contact conductive rod integrates the current sensing module with the contactor, eliminating the need for additional busbars and wiring, significantly reducing the product's size and weight.

[0037] Example 4: Soft-start circuit like Figure 3As shown, the soft-start circuit is equipped with a soft-start current-limiting resistor interface, through which a bypass circuit is connected. The bypass circuit includes a current-limiting resistor R and a bypass switch (composed of a MOSFET or relay controlled by the processor). The resistance value of the current-limiting resistor R is selected according to the load capacitance and the desired charging time constant, with a typical value of 1-100Ω and a power rating of 50-200W.

[0038] The soft-start process is as follows: When the processor receives the power-on command, it first performs a circuit status check (including whether the voltage is over / undervoltage, whether there is a fault latch, etc.). After confirming that everything is normal, it controls the bypass switch to close, the bypass circuit is connected, and the power supply charges the load capacitor through the current-limiting resistor R. The charging current is limited to the range I=V / R, which is much smaller than the current spike of tens or even hundreds of amperes when directly connected. After a set delay T, the voltage of the load capacitor rises to close to the power supply voltage. At this time, the processor controls the bypass switch to open and immediately controls the optoMOSFET to turn on, the contactor coil is energized, the main contacts close, and the load switches to the main circuit power supply.

[0039] The technical advantages of this bypass switching soft starter are as follows: First, the current-limiting resistor effectively suppresses the charging current during the bypass phase, avoiding the arcing impact of current spikes on the main contacts; second, the load-side capacitor is already fully charged when the main contacts are engaged, and there is almost no inrush current at the moment the contacts are connected, which greatly reduces the electrical wear of the contacts; third, the entire soft start process only takes tens of milliseconds, without affecting the system's response speed; fourth, the soft starter circuit has a simple structure, requiring only a current-limiting resistor and switching devices, resulting in high reliability and low cost.

[0040] Example 5: Implementation of Protection Function The protective functions of this invention include I 2 The inverse-time overcurrent protection, short-circuit protection, overvoltage protection, and undervoltage warning functions are implemented based on the following principles: I 2 Inverse-time overcurrent protection: The processor samples the main contact current value at a frequency of 1kHz, squares and accumulates each sampled value. When the accumulated value exceeds the set I... 2 The protection action is triggered when the T threshold is reached. The inverse time characteristic curve follows I... 2 The mathematical relationship T=K, where the value of K can be modified online via the CAN bus. The starting protection point can also be modified online. This protection feature allows for a longer duration for minor overcurrents and rapid action for severe overcurrents, matching the thermal characteristics of the protected device.

[0041] Short circuit protection: When the real-time current value exceeds the short circuit protection point, the processor immediately executes the protection action without going through I... 2 The cumulative delay (T) ensures that the circuit is quickly disconnected in the event of a short-circuit fault, preventing the fault from escalating.

[0042] Overvoltage protection: The voltage acquisition circuit acquires the load terminal voltage through an isolation operational amplifier. When the voltage exceeds the set overvoltage protection point, the processor executes contact disconnection protection. Undervoltage warning: When the voltage is lower than the undervoltage point, the processor sends an undervoltage warning message via the CAN bus, but does not execute contact disconnection, allowing the system to continue operating in the undervoltage state for operator judgment and handling.

[0043] Post-protection self-locking: After any of the above protection actions are executed, the processor controls the opto-MOS to turn off, opening the main contacts, and simultaneously outputs a latch signal to the post-protection self-locking circuit. The post-protection self-locking circuit consists of a D flip-flop or an SR latch, and the latched state output is fed back to the processor's input pin, ensuring the processor remains in the protected state even after the fault disappears. Only when the operator sends a reset command via the CAN bus, and the processor outputs a reset signal to release the self-lock, will the system be allowed to receive the reconnection command again. This hardware self-locking mechanism ensures reliable maintenance after fault protection, unaffected by software anomalies or electromagnetic interference.

Claims

1. A novel soft-start intelligent high-voltage DC contactor, comprising a high-voltage DC contactor and an intelligent control module, characterized in that: The high-voltage DC contactor includes main contacts, a contactor coil, and auxiliary contacts; The intelligent control module includes a processor, a CAN communication circuit, an optical MOS driving circuit, a soft-start circuit, a voltage and current acquisition circuit, and a protection self-locking circuit. The processor is connected to the CAN communication circuit, the optical MOS driving circuit, the soft-start circuit, the voltage acquisition circuit, and the protection self-locking circuit, respectively. The processor receives control commands through the CAN communication circuit, controls the soft start circuit to first connect the bypass circuit to charge the load end capacitor, and after a set delay, controls the contactor coil to be energized through the optical MOS drive circuit to make the main contacts close. The voltage and current acquisition circuit acquires the voltage and current values ​​of the main contacts and transmits them to the intelligent control module. The processor performs overcurrent protection, short circuit protection, undervoltage warning and overvoltage protection based on the acquired current and voltage values, and performs self-locking through the self-locking circuit after protection. The processor reports information such as the contactor's working status, current and voltage values, and contact engagement count in real time via the CAN communication circuit. The number of times the contactor engages is collected through auxiliary contacts, and the health status of the contactor is fed back to the processor through the health monitoring module.

2. The novel soft-start intelligent high-voltage DC contactor according to claim 1, characterized in that: The optical MOS driving circuit includes an optical MOS. The front end of the optical MOS is connected to a 5V power supply and its on / off state is controlled by a processor. The rear end is connected to a contactor coil and is powered by an isolated 28V power supply. The processor controls the on / off state of the optical MOS by receiving instructions or judging whether the circuit needs protection, and then controls the on / off state of the contactor coil and the closing of the main contacts.

3. The novel soft-start intelligent high-voltage DC contactor according to claim 1, characterized in that: The current sensor is a Hall sensor, nested on the main contact, which collects the current value of the main contact and outputs it to the intelligent control module in analog form.

4. The novel soft-start intelligent high-voltage DC contactor according to claim 1, characterized in that: The soft-start circuit is equipped with a soft-start current-limiting resistor interface. The bypass circuit is connected through the soft-start current-limiting resistor interface. When powered on, the bypass circuit is first connected to charge the capacitor at the load end. After a set time, the circuit is switched to the main circuit to avoid damage to the main contacts caused by the instantaneous current spike.

5. The novel soft-start intelligent high-voltage DC contactor according to claim 1, characterized in that: The self-locking circuit after protection will self-lock after the main contacts are opened in the event of overvoltage, overload or short circuit, ensuring that the main contacts are open until a new control command is received. The self-locking will be released when a reset command is received through the CAN communication circuit.

6. The novel soft-start intelligent high-voltage DC contactor according to claim 1, characterized in that: The processor executes I based on the collected main contact current value. 2 It has overcurrent protection and short-circuit protection functions. It performs overvoltage protection and undervoltage warning functions based on the collected voltage value. The starting protection point and inverse time current protection characteristic curve of the overcurrent protection function can be modified online through the CAN communication circuit.

7. The novel soft-start intelligent high-voltage DC contactor according to claim 1, characterized in that: The intelligent control module can be controlled via I / O and CAN bus redundancy.

8. The novel soft-start intelligent high-voltage DC contactor according to claim 1, characterized in that: The intelligent control module and the high-voltage DC contactor are designed as separate units and are fixed with screws; a shielding alloy is provided between the high-voltage DC contactor and the intelligent control module.

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