An integrated intelligent ac contactor

Abstract

The application discloses an integrated intelligent AC contactor, which comprises a contactor and an intelligent control module integrated thereon, and the intelligent control module comprises a main control processor, an isolated CAN communication module, a signal acquisition module, an isolated driving module, a configurable protection module and a contact state detection unit. 2 The product adopts isolated optical coupling matched with PNP Darlington tube to realize coil isolation driving, and realizes strong and weak electric isolation parameter acquisition through a Hall sensor, and is provided with I 2 T inverse time overcurrent, short circuit, overvoltage, wrong phase and multiple protection and alarm functions, the protection parameters can be configured online and the protection function switch can be switched; a double-cavity layout is matched with a permalloy insert shield, and a triple anti-interference system is formed by combining isolated power supply and isolated communication. The application has high integration, strong anti-interference ability and wide adaptation scene, and can realize intelligent control and full life cycle state monitoring of the contactor.

Description

Technical Field

[0001] This invention relates to the field of contactors, and more particularly to an integrated intelligent AC contactor. Background Technology

[0002] AC contactors, as key control components in power systems, are widely used in aircraft power distribution networks, industrial automation control, and new energy power distribution. In existing technologies, contactor control often involves the main system directly controlling the coil. If protection, data acquisition, and communication functions are required, control circuits, drive circuits, and voltage conversion circuits need to be designed on the main control circuit, leading to increased complexity and hindering troubleshooting and maintenance.

[0003] Existing intelligent contactors have limited control functions and lack integration with communication and intelligent protection. For example, an intelligent contactor disclosed in CN221841775U controls the opening and closing of three-phase contacts through a main control board. Its control function is limited to "on and off," lacking communication capabilities and thus failing to achieve real-time transmission and remote monitoring of operational data. While this patent achieves precise opening and closing of the moving and stationary contact components through precise control of the electromagnetic drive components via the main control board, it lacks the ability to acquire parameters such as current, voltage, and frequency in real time. It also cannot automatically execute functions such as inverse-time overcurrent protection, short-circuit protection, overvoltage protection, frequency anomaly protection, and anomaly alarms, resulting in a single control dimension.

[0004] Furthermore, the use of external modules leads to circuit interference and low integration. For example, CN223140663U discloses a contactor with an external control module. This module uses external modules for basic monitoring, requiring external circuit connections between modules, which easily introduces interference. The control module in this patent includes a module housing and a plug located outside the housing. The housing is mounted outside the contactor housing, and the plug is electrically connected to the built-in components via a socket located inside the housing, at least electrically connected to the coil and mating with the plug. While this external design facilitates maintenance, the modules are scattered, have basic functions, lack configuration capabilities, and the external wiring increases system complexity and interference risks.

[0005] The anti-interference solutions are simplistic and lack multi-layered isolation designs. For example, the aviation intelligent AC contactor disclosed in CN206293364U only uses a metal casing with electrical isolation for anti-interference, and requires an external controller for protection. The anti-interference solution in this patent is relatively basic, failing to adopt a multi-layered system combining physical and material isolation, and the acquisition, control, and communication are not integrated into a single design, resulting in low integration. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies by providing an integrated intelligent AC contactor. It integrates control circuits, drive circuits, voltage conversion circuits, and other circuits into a single intelligent module. Employing an integrated structural design, an external structural design is added to the contactor, and connectors are used to connect the contactor to the control module. The intelligent contactor also connects to the main unit via connectors. The intelligent control unit is secured with a mounting bracket and screws, resulting in a compact structure and easy disassembly. The intelligent control unit is housed in a separate cavity from the contactor, within a cavity containing plastic and permalloy inserts. Permalloy effectively shields against low-frequency electromagnetic interference, ensuring circuit stability and high reliability. Furthermore, the intelligent control unit is adaptable to contactors with different rated loads, offering high applicability.

[0007] The technical solution of the present invention: An integrated intelligent AC contactor includes a contactor and an intelligent control module mounted on the contactor. The contactor has input contacts and output contacts. The intelligent control module includes a main control processor, an isolated CAN communication module, a signal acquisition module, an isolated drive module, a protection module, and a contact status detection unit.

[0008] The isolated CAN communication module is connected to the main control processor and uses an isolated CAN transceiver to achieve bus communication with the external host. It blocks ground loop interference between the external bus and the main control circuit through opto-isolation and electrical isolation, thereby improving the communication stability under multi-device networking. At the same time, it supports the issuance of control commands and the uploading of operating data, realizing remote management and control of contactors and adapting to the networking requirements of multi-node power distribution systems.

[0009] The signal acquisition module is used to collect the current, voltage, and frequency signals of the contactor's main contacts and transmit them to the main control processor. The module employs a Hall-effect AC current sensor paired with a multi-channel AD acquisition chip. The Hall sensor achieves non-contact current acquisition based on the Hall effect. There is no direct electrical connection between the main circuit's high-voltage and control circuit's low-voltage circuits, ensuring reliable separation of high and low voltage electrical parameters while achieving high-precision, high-response-speed electrical parameter acquisition and improving the product's dielectric withstand voltage rating. The collected multi-dimensional electrical parameters provide a complete data foundation for protection logic judgment and status reporting. The Hall-effect AC current sensor is installed in the main circuit between the input and output contacts. AC current passes through the Hall sensor's busbar. Based on the Hall effect principle, the sensor converts the current magnetic field in the main circuit into an analog voltage signal proportional to the current. This analog voltage signal is output to the AD acquisition chip via an electrical connector. After analog-to-digital conversion by the AD acquisition chip, it is transmitted to the main control processor for processing via communication. Because the Hall sensor achieves complete electrical isolation between the primary side (high-voltage side of the main circuit) and the secondary side (low-voltage side of the signal output), with an isolation withstand voltage of up to several kilovolts, it effectively separates the high-voltage side of the contactor's main contacts from the low-voltage side of the intelligent control module. Compared to surface-mount current sensors that are directly mounted on the control circuit board, this invention avoids power current flowing through the control module. Electromagnetic interference generated during contactor startup will not affect the control module, while also improving the product's dielectric withstand voltage performance, making the product more stable and reliable during operation.

[0010] The isolation drive module includes an isolation optocoupler and a PNP Darlington transistor. The front end of the isolation optocoupler is connected to the main control processor and its on / off state is controlled by the main control processor. The rear end of the isolation optocoupler is connected to the base of the Darlington transistor. The emitter of the Darlington transistor is connected to the negative terminal of the contactor coil. The collector of the Darlington transistor is grounded. The positive terminal of the contactor coil is connected to the power supply voltage. The control signal output by the main control processor first controls the on / off state of the front end of the isolation optocoupler. Through opto-isolation, electrical isolation between the weak current on the control side and the strong current on the coil side is achieved, avoiding damage to the main control circuit by the back voltage when the coil is de-energized. The drive signal output by the optocoupler controls the base of the Darlington transistor. The high current gain characteristic of the Darlington transistor is used to amplify the drive current, meeting the large starting current requirement of the contactor coil. Compared with the traditional opto-MOS drive solution, it is smaller in size and lower in cost, and is suitable for integrated compact structures. The main control processor controls the energization state of the contactor coil by controlling the on / off timing of the isolation optocoupler and the Darlington transistor, thereby controlling the closing or releasing of the contactor contacts. The isolated drive module employs a drive scheme combining an isolation optocoupler and a cascaded PNP Darlington transistor. The front end of the isolation optocoupler is connected to a 3.3V power supply, controlled by the main control processor via GPIO pins. The rear end of the optocoupler is connected to the base of the Darlington transistor, with the collector grounded and the emitter connected to the negative terminal of the contactor coil. The positive terminal of the contactor coil is connected to a 28V power supply. When the main control processor outputs a high level, the LED at the front end of the optocoupler conducts, activating the phototransistor at the rear end, providing drive current to the base of the Darlington transistor. The Darlington transistor conducts, energizing the contactor coil and causing the main contacts to close. When the main control processor outputs a low level, the optocoupler turns off, the Darlington transistor loses its drive current and turns off, de-energizing the contactor coil and releasing the main contacts. The Darlington transistor, composed of two cascaded transistors, has a current amplification factor of several hundred times, enabling the drive of a high-current load on the contactor coil with a relatively small base current. Considering the large starting current and operating voltage of the coil, but the large size and high price of the optical MOS, an isolation optocoupler plus a Darlington transistor is used to replace the optical MOS for driving. This reduces the size and lowers the cost while ensuring driving capability.

[0011] The protection module is configured in the main control processor and has a delayed start function. Based on the current, voltage, and frequency signals collected by the signal acquisition module, it executes overcurrent alarm, over / undervoltage alarm, phase loss / phase reversal alarm, and I / O alarm. 2 The system includes inverse-time overcurrent protection, short-circuit protection, overvoltage protection, and phase reversal protection, and self-locks after performing the protection action; the delayed start function can shield the inrush current at the moment of contactor engagement, preventing false triggering of the protection; 2The inverse-time overcurrent protection is based on the principle of current thermal effect. The larger the fault current, the shorter the protection action time, balancing the overload tolerance of the load with the need for rapid fault clearing. The short-circuit protection achieves instantaneous action, quickly cutting off severe faults to protect downstream equipment. The self-locking after protection action can prevent repeated closing under fault conditions and avoid fault expansion. Various alarm thresholds, starting protection points, inverse-time current protection parameters, and delayed start time can be modified online via isolated CAN communication to receive configuration commands from an external host, adapting to different load characteristics. At the same time, the protection function can be configured to be in a disabled state. When enabled, the coil power supply is automatically cut off and self-locked during a fault. When disabled, only alarm commands are reported and no protection shutdown action is performed, meeting the forced power supply requirements in special scenarios.

[0012] The contact status detection unit is configured in the main control processor. It collects the number of contactor contacts engaging through auxiliary contacts and reports the engagement number to an external host through the isolated CAN communication module. By accumulating the engagement number and combining it with the mechanical life characteristics of the contactor, the health status of the contactor can be quantitatively assessed, realizing full life cycle operation and maintenance management, and facilitating maintenance personnel to predict faults in advance and formulate maintenance plans.

[0013] The intelligent control module is connected to an external host via an electrical connector. The coils of the intelligent control module and the contactor are housed in different cavities, and physical spatial isolation structurally blocks the direct radiation interference of the coil magnetic field to the control circuit. The inner wall of the cavity containing the intelligent control module is provided with a permalloy insert, which forms an electromagnetic shielding shell. Permalloy has high initial permeability, which can effectively absorb and bypass the low-frequency electromagnetic interference generated when the contactor engages and disengages, protecting the main control processor, communication circuit, and acquisition chip from magnetic field disturbances, and ensuring acquisition accuracy and communication stability. Combined with the aforementioned isolated drive, isolated power supply, and isolated communication design, a triple anti-interference system of "electrical isolation + physical cavity isolation + material shielding" is formed, which greatly improves the operational reliability of the product in a strong electromagnetic environment.

[0014] The above-mentioned technical features work together to achieve intelligent control of the entire process of "collection-judgment-execution-reporting". All functions are integrated into a single intelligent module and installed in one piece with the contactor. No external circuit is required. It has a compact structure, high power density, and is suitable for compact power distribution scenarios such as airborne and vehicle-mounted systems.

[0015] The beneficial effects of this invention are: (1) The control, acquisition, protection, communication and electromagnetic shielding functions are integrated into a single intelligent module and fixed with the contactor by a screw mounting bracket. The structure is compact and small in size, and no external auxiliary circuit is required, which greatly reduces the complexity of the power distribution system and facilitates installation, disassembly and troubleshooting.

[0016] (2) Through isolation drive, isolation power supply and isolation CAN communication, the entire link electrical isolation is achieved. Combined with the triple anti-interference system of dual cavity physical isolation and permalloy material shielding, the electromagnetic interference of the coil and crosstalk between systems are effectively suppressed, ensuring the acquisition accuracy and communication stability, and adapting to strong electromagnetic complex environment.

[0017] (3) It has the functions of multi-dimensional electrical parameter acquisition and full-type fault protection. The alarm threshold, protection start point, inverse time characteristic parameters and delay start time can all be configured online. It also supports the switching of protection function on / off. It can realize conventional load protection and meet the forced power supply requirements of special scenarios, and is suitable for a wide range of scenarios.

[0018] (4) Supports the statistics of contact engagement times and health status assessment. Operating electrical parameters and working status data are reported in real time through the CAN bus to realize remote monitoring and full life cycle management, and improve the intelligent operation and maintenance level of the power distribution system. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the system principle of the intelligent AC contactor of the present invention.

[0020] Figure 2 This is a schematic diagram of the contactor coil driving principle of the present invention.

[0021] Figure 3 This is a schematic diagram of the isolated power supply and isolated communication technology of the present invention.

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

[0023] Figure 5 This is a schematic diagram of the external structure of the intelligent AC contactor of the present invention.

[0024] In the diagram: 1-Electrical connector, 2-Current sensor, 3-Intelligent control module, 4-Permalloy insert, 5-Input contact, 6-Output contact, 7-Contaminator. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0026] I. Overall Structure like Figure 5As shown, the integrated intelligent AC contactor of the present invention includes a contactor 7 and an intelligent control module 3 mounted on the contactor 7. The intelligent control module 3 is fixed to the housing of the contactor 7 by a mounting bracket and screws, resulting in a compact structure that facilitates installation and disassembly. The contactor 7 has input contacts 5 and output contacts 6 for the input and output of three-phase AC power.

[0027] like Figure 4 As shown, the coils of the intelligent control module 3 and the contactor 7 are located in different cavities. The inner wall of the cavity containing the intelligent control module 3 is fitted with a permalloy insert 4, which forms an electromagnetic shielding shell, enclosing the intelligent control module 3 and creating a metal shielding mesh. The permalloy insert 4 is made of 1J50 or 1J79 iron-nickel soft magnetic alloy material, possessing high permeability and low coercivity characteristics, effectively reducing low-frequency electromagnetic interference generated when the contactor coil engages or disengages.

[0028] The intelligent control module 3 is connected to the external host via electrical connector 1. Electrical connector 1 is an aerospace-grade connector with multiple pins for power supply, CAN communication, analog signal transmission, etc.

[0029] II. Internal Structure of the Intelligent Control Module like Figure 1 As shown, the intelligent control module 3 includes a main control processor, an isolated CAN communication module, a signal acquisition module, an isolated drive module, a protection module, a contact status detection unit, and an isolated power supply module.

[0030] The main control processor uses a 32-bit ARM Cortex-M series microcontroller with a main frequency of 72MHz. It has multiple ADC input channels, multiple GPIO output channels, a CAN communication interface, timers, and other peripheral resources. The main control processor has built-in non-volatile memory (Flash) for storing protection parameters, operation logs, and other data.

[0031] The isolated CAN communication module includes an isolated CAN transceiver. The isolated CAN transceiver uses magnetic isolation technology to achieve electrical isolation between the CAN signal and the external bus, with an isolation withstand voltage of 2500V. The TXD and RXD pins of the isolated CAN transceiver are connected to the CAN_TX and CAN_RX pins of the main control processor, while the CAN_H and CAN_L pins are connected to the CAN bus of the external host via electrical connector 1.

[0032] The signal acquisition module includes a Hall-effect AC current sensor 2 and an AD acquisition chip. The Hall-effect AC current sensor 2 is located in the main circuit between input contact 5 and output contact 6, and is used to acquire the current value of the main contact in real time. The Hall-effect AC current sensor 2 is a three-phase integrated Hall sensor with a rated measuring current of 50A, a measuring range of ±100A, and an output analog voltage signal. The AD acquisition chip uses a multi-channel 16-bit high-precision ADC with a sampling rate of 100kSPS and multiple differential input channels, respectively connected to the output signal, voltage sampling signal, and frequency sampling signal of the Hall-effect AC current sensor 2.

[0033] The isolation drive module includes an isolation optocoupler and a PNP Darlington transistor. The front end of the isolation optocoupler is connected to a 3.3V power supply. The anode of the LED is connected to a 3.3V power supply after a current-limiting resistor in series, and the cathode is connected to the GPIO control pin of the main control processor. The collector of the phototransistor at the rear end of the isolation optocoupler is connected to the base of the Darlington transistor, and the emitter is grounded. The Darlington transistor is a TIP127 PNP Darlington power transistor, with its collector grounded and its emitter connected to the negative terminal of the contactor coil. The positive terminal of the contactor coil is connected to a 28V power supply. The main control processor controls the on / off state of the isolation optocoupler and the Darlington transistor by controlling the level state of the GPIO pins, thereby controlling the energizing state of the contactor coil.

[0034] The protection module is configured in software within the main control processor, including a delayed start unit, an overcurrent alarm unit, an over / under voltage alarm unit, a phase loss / phase reversal alarm unit, and I / O. 2 The system includes an inverse-time overcurrent protection unit, a short-circuit protection unit, an overvoltage protection unit, and a phase reversal protection unit. The parameters of each protection unit can be configured online via CAN communication.

[0035] The contact status detection unit is configured in software within the main control processor. It collects the number of contactor contacts closing via auxiliary contacts. The auxiliary contacts are normally open and are linked to the main contacts. Each time the main contacts close, the auxiliary contacts close, generating a pulse signal that is input to the external interrupt pin of the main control processor. The main control processor then counts these pulse signals.

[0036] The isolated power supply module uses an isolated DC-DC converter with an input voltage of 28V and output voltages of 3.3V and 5V, and an isolation withstand voltage of 1500V. The isolated power supply module provides all circuits within the intelligent control module 3 with operating power isolated from the external power supply system.

[0037] III. Work Process 1. Connection Process When the main control processor receives the connection command sent by the external host through the isolated CAN communication module, it first determines whether the circuit status is normal, that is, checks whether there are abnormal states such as overcurrent, overvoltage, phase reversal, or phase loss.

[0038] If the circuit is functioning normally, the main controller first initiates a delayed start timer. The delayed start time can be configured via CAN communication, with a default value of 0ms (i.e., no delay). After the delay period, the main controller outputs a high level on the GPIO pin, activating the LED at the front end of the optocoupler and causing the phototransistor at the rear to conduct, providing drive current to the Darlington transistor's base. Once the Darlington transistor is activated, the contactor coil is energized, generating electromagnetic attraction that drives the moving iron core to close, closing the main contacts. Three-phase AC power is then transmitted to the load through input contact 5 and output contact 6.

[0039] After the main contacts close, the auxiliary contacts close synchronously, generating a pulse signal. The main control processor counts this pulse signal and records one closing action. At the same time, the main control processor reports the contactor's operating status (on state) to the external host in real time via the isolated CAN communication module.

[0040] 2. Operation monitoring and protection process After the contactor is activated, the signal acquisition module collects the current, voltage, and frequency values ​​of each phase's main contacts in real time. Current acquisition: Hall effect AC current sensor 2 converts the AC current in the main circuit into an analog voltage signal proportional to the current. After analog-to-digital conversion by the AD acquisition chip, the signal is transmitted to the main control processor. The main control processor determines whether protection needs to be activated based on the current value. If the current exceeds the set overcurrent alarm threshold but does not reach the starting overcurrent protection point, the main control processor will send an alarm command through the isolated CAN communication module. If the current reaches the initial overcurrent protection point, the main control processor will activate I... 2 The inverse-time overcurrent protection calculation is based on the current magnitude and duration, and the inverse-time characteristic curve is used to determine whether protection action is required. The larger the current, the faster the protection action. If the current reaches the short-circuit protection point, the main control processor will immediately execute the short-circuit protection action.

[0041] Voltage Acquisition: The voltage sampling circuit converts the high voltage of the main circuit into a low voltage signal suitable for ADC acquisition using a resistor divider. After analog-to-digital conversion by the ADC chip, the signal is transmitted to the main control processor. The main control processor then determines the following based on the voltage value: If the voltage exceeds the set overvoltage threshold, overvoltage protection will be activated. If the voltage is lower than the set undervoltage threshold, an undervoltage alarm will be sent; If the voltage is within the normal range, continue monitoring.

[0042] Frequency Acquisition: The frequency sampling circuit acquires the frequency information of the three-phase AC power through zero-crossing detection and transmits it to the main control processor. The main control processor then determines the following based on the frequency value: If a phase error occurs in the three-phase frequency (i.e., a three-phase phase sequence error), the phase error protection will be triggered. If a phase frequency is missing, a phase loss alarm is triggered. When the protection function is enabled, if the main control processor detects abnormal signals such as overcurrent, overvoltage, phase reversal, or short circuit, it immediately executes protection actions: controlling the GPIO pin to output a low level, shutting off the optocoupler, causing the Darlington transistor base to lose drive current and turn off, de-energizing the contactor coil, and releasing the main contacts. Simultaneously, the main control processor performs a self-locking operation, locking the contactor in the open state to prevent automatic reconnection. In the self-locking state, even if a reconnection command is received again, the contactor will not engage; a reset command must be sent via CAN communication to release the self-locking state before a reconnection command can be sent to activate it.

[0043] When the protection function is off, if the main control processor detects abnormal signals such as overcurrent, overvoltage, or phase reversal, it will only report an alarm command through the isolation CAN communication module and will not execute the protection shutdown action; the contactor will remain in the on state.

[0044] 3. Shutdown process When the main control processor receives a shutdown command from the external host, it controls the GPIO pin to output a low level, shutting off the isolation optocoupler. The Darlington transistor base loses its drive current and turns off, de-energizing the contactor coil. The electromagnetic attraction disappears, the moving iron core is released under the action of the reset spring, the main contacts open, and the three-phase AC power is disconnected from the load. The auxiliary contacts open synchronously. The main control processor records one release action and reports the contactor's operating status (disconnected state) to the external host in real time via the isolated CAN communication module.

[0045] 4. Parameter Configuration Process The external host sends configuration frames via the CAN bus. These frames contain fields such as frame ID, parameter type, and parameter value. Upon receiving the configuration frame, the main control processor parses the frame ID to confirm if it is a configuration command, parses the parameter type to identify the parameters to be configured (such as overcurrent alarm threshold, initial overcurrent protection point, inverse time current protection parameters, and delayed start time), parses the parameter value to obtain new parameter data, writes the new parameter data into non-volatile memory, and sends a configuration success confirmation frame via the isolated CAN communication module. The isolated CAN transceiver uses magnetic or optical isolation technology to electrically isolate the communication signal from the external bus, with isolation withstand voltage typically exceeding 2500V. The main control processor parses the on / off commands, parameter configuration commands, and status query commands sent by the external host via the CAN protocol stack. Simultaneously, it reports the current, voltage, frequency, contact engagement counts, and contactor operating status collected by the signal acquisition module to the external host in real time via the isolated CAN communication module. Because the CAN bus uses differential signal transmission, it has strong anti-interference capabilities. Combined with isolation design, it effectively avoids communication interference between devices in a multi-device distribution box, ensuring the reliability of data transmission.

[0046] 5. Status reporting process During contactor operation, the main control processor transmits the current, voltage, and frequency values ​​collected by the signal acquisition module, as well as the contact engagement count collected by the contact status detection unit, along with the contactor's operating status, to the external host in real time via the isolated CAN communication module at fixed intervals (e.g., 100ms). The transmitted data frame includes fields such as frame ID, current value, voltage value, frequency value, engagement count, and operating status.

Claims

1. An integrated intelligent AC contactor, comprising a contactor and an intelligent control module mounted on the contactor, wherein the contactor has input contacts and output contacts, characterized in that, The intelligent control module includes: Main control processor; An isolated CAN communication module is connected to the main control processor and is used to communicate with an external host via a bus through an isolated CAN transceiver. The signal acquisition module is used to acquire the current, voltage, and frequency signals of the main contacts of the contactor and transmit them to the main control processor. An isolation drive module includes an isolation optocoupler and a PNP Darlington transistor. The front end of the isolation optocoupler is connected to the main control processor and its on / off state is controlled by the main control processor. The rear end of the isolation optocoupler is connected to the base of the Darlington transistor. The emitter of the Darlington transistor is connected to the negative terminal of the contactor coil. The collector of the Darlington transistor is grounded. The positive terminal of the contactor coil is connected to the power supply voltage. The main control processor controls the energization state of the contactor coil by controlling the on / off state of the isolation optocoupler and the Darlington transistor, thereby controlling the closing or releasing of the contactor contacts. The protection module, configured in the main control processor, has a delayed start function. Based on the current, voltage, and frequency signals acquired by the signal acquisition module, it executes overcurrent alarm, over / undervoltage alarm, phase loss / phase reversal alarm, and I / O alarm. 2 The system includes inverse-time overcurrent protection, short-circuit protection, overvoltage protection, and phase reversal protection, and performs self-locking after executing the protection action. A contact status detection unit, configured in the main control processor, is used to collect the number of times the contactor contacts engage through auxiliary contacts, and report the number of engagements to an external host through the isolated CAN communication module; The intelligent control module is connected to an external host via an electrical connector. The intelligent control module and the contactor coil are located in different cavities. The inner wall of the cavity where the intelligent control module is located is provided with a permalloy insert, which forms an electromagnetic shielding cover.

2. The integrated intelligent AC contactor according to claim 1, characterized in that, The front end of the isolation optocoupler is connected to a 3.3V power supply. The main control processor controls the conduction state of the Darlington transistor at the back end by controlling the on / off state of the front end of the isolation optocoupler. After receiving the on command from the external host and determining that the circuit status is normal, it sequentially controls the isolation optocoupler and the Darlington transistor to conduct, so that the contactor coil is energized and the main contacts are engaged. After receiving the off command from the external host or protection trigger, it sequentially controls the Darlington transistor and the isolation optocoupler to turn off, so that the contactor coil is de-energized and the main contacts are released.

3. The integrated intelligent AC contactor according to claim 1, characterized in that, The signal acquisition module includes a Hall effect AC current sensor and an AD acquisition chip. The Hall effect AC current sensor is connected to the AD acquisition chip in analog form via an electrical connector to separate the high voltage on the main contact side of the contactor from the low voltage on the intelligent control module side. The intelligent control module also includes an isolated power supply module, which provides the intelligent control module with a working power supply isolated from the external power supply system.

4. The integrated intelligent AC contactor according to claim 1, characterized in that, The protection function of the protection module can be configured to be off. When the protection function is on, the main control processor automatically cuts off the power supply of the isolation drive module to the contactor coil and performs self-locking when it detects overcurrent, overvoltage or phase reversal signals. When the protection function is off, the main control processor only reports an alarm command through the isolation CAN communication module when it detects overcurrent, overvoltage or phase reversal signals, and does not perform protection shutdown action.

5. The integrated intelligent AC contactor according to claim 1, characterized in that, The intelligent control module is fixed to the housing of the contactor using a mounting bracket and screws.

6. The integrated intelligent AC contactor according to claim 3, characterized in that, The Hall effect AC current sensor is installed in the main circuit between the input contact and the output contact to collect the main contact current value in real time.

7. The integrated intelligent AC contactor according to claim 1, characterized in that, The alarm thresholds, starting protection points, inverse time current protection parameters, and delayed start times in the protection module can be modified online by receiving configuration commands from an external host through the isolated CAN communication module.

8. The integrated intelligent AC contactor according to claim 1, characterized in that, During the operation of the contactor, the main control processor reports the current value, voltage value, and frequency value collected by the signal acquisition module, as well as the number of contact engagements collected by the contact status detection unit, along with the working status of the contactor, to the external host in real time through the isolated CAN communication module.

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