An intelligent electronic dc contactor and electrical device

Abstract

This application provides an intelligent electronic DC contactor and electrical equipment. The intelligent electronic DC contactor includes: an isolation voltage conversion circuit for receiving a low-voltage side voltage and isolating and converting the low-voltage side voltage to obtain a high-voltage side driving voltage; an input isolation circuit for detecting a switch control signal on the low-voltage side and isolating and outputting the switch control signal to the high-voltage side; a high-voltage side driving circuit for controlling the output of the driving voltage upon receiving the switch control signal; and a main switching circuit for driving each switch transistor to synchronously turn on or off according to the driving voltage, thereby controlling the on / off state of the connected DC power supply line. Compared with mechanical intelligent electronic DC contactors, this intelligent electronic DC contactor has the characteristics of long life, high reliability, and fast protection. In addition, it can be expanded to include functions such as voltage, current, and temperature information acquisition, providing a foundation for realizing intelligent power supply control.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to an intelligent electronic DC contactor and electrical equipment. Background Technology

[0002] Mechanical contactors are currently widely used in control consoles and other equipment on large transportation vehicles such as subways and high-speed trains. Mechanical contactors typically use electromagnetic coils to generate attraction force to control the closing of mechanical contacts, thereby controlling the switching of the connected power supply line. However, mechanical contactors also have some problems. For example, frequent switching operations can lead to material fatigue, accelerating the lifespan of the mechanical structure. Furthermore, in some complex operating environments, the mechanical contacts are susceptible to external environmental factors such as temperature, humidity, and salinity, leading to reduced reliability. In addition, the function of mechanical contactors is relatively limited; they cannot automatically disconnect in case of a fault, thus failing to protect the equipment. Summary of the Invention

[0003] In view of this, embodiments of this application provide an intelligent electronic DC contactor and electrical equipment.

[0004] In a first aspect, embodiments of this application provide an intelligent electronic DC contactor, comprising:

[0005] An isolation voltage conversion circuit is used to receive a low-voltage side voltage, isolate and convert the low-voltage side voltage to obtain a high-voltage side driving voltage;

[0006] An input isolation circuit is connected to the output terminal of the isolation voltage conversion circuit. It is used to detect the switching control signal on the low-voltage side and isolate and output the switching control signal to the high-voltage side.

[0007] A high-voltage side drive circuit, connected to the output terminal of the isolation voltage conversion circuit and the input isolation circuit, is used to control the output of the drive voltage when the switch control signal is received;

[0008] The main switching circuit has an input terminal for receiving DC power, an output terminal for outputting DC power, and a control terminal connected to the high-voltage side drive circuit. The main switching circuit is used to drive each switch in the main switching circuit to be synchronously turned on or off according to the drive voltage, thereby controlling the on / off state of the connected DC power supply line.

[0009] In some embodiments, the main switching circuit includes a first switching unit and a second switching unit, wherein the first switching unit includes a first switching transistor and the second switching unit includes a second switching transistor;

[0010] The control terminals of the first and second switching transistors are both connected to the drive output pins of the high-voltage side drive circuit. The first signal terminal of the first switching transistor is used to connect to the DC power, the second signal terminal of the first switching transistor is connected to the second signal terminal of the second switching transistor, and the first signal terminal of the second switching transistor is used to output the DC power.

[0011] In some embodiments, the main switching circuit further includes a third switching unit and a fourth switching unit, wherein the third switching unit includes a third switching transistor and the fourth switching unit includes a fourth switching transistor;

[0012] The control terminals of the third and fourth switching transistors are both connected to the drive output pin. The third switching transistor is connected to the first signal terminal of the first switching transistor, and the third switching transistor is connected to the second signal terminal of the first switching transistor. The fourth switching transistor is connected to the first signal terminal of the second switching transistor, and the fourth switching transistor is connected to the second signal terminal of the second switching transistor.

[0013] In some embodiments, each of the switching units further includes a first resistor, a second resistor, and a bidirectional diode;

[0014] The control terminal of each of the switching transistors is connected to the drive output pin via the first resistor in its respective switching unit. The second resistor and the bidirectional diode are connected in parallel, with one end connected to the control terminal of the switching transistor and the other end connected to the second signal terminal of the switching transistor.

[0015] In some embodiments, the input isolation circuit includes a first optocoupler, a first Zener diode, a first RC parallel unit, and a second RC parallel unit;

[0016] One end of the first RC parallel unit is connected to the transmitting side of the first optocoupler and is also used to receive the switch control signal; the other end is connected to the low-voltage side power ground.

[0017] The receiver-side collector of the first optocoupler is used to connect to the power supply voltage, and the emitter is connected to the high-voltage side drive circuit and one end of the second RC parallel unit after passing through the first Zener diode. The other end of the second RC parallel unit is connected to the high-voltage side power supply ground.

[0018] In some embodiments, the high-voltage side drive circuit includes a floating drive chip, an adjustment capacitor, a current-limiting resistor, first to second diodes, a voltage divider unit, and an RC series unit, wherein the floating drive chip includes multiple functional pins;

[0019] The floating drive chip has a chip power supply pin for connecting to the supply voltage, a signal input pin for connecting to the input isolation circuit, a drive power supply pin for connecting to the drive voltage via the first diode, a drive output pin for connecting to the control terminal of the main switching circuit and the current limiting resistor, and a current sampling pin for connecting to the voltage divider output terminal of the voltage divider unit and the regulating capacitor.

[0020] The other end of the current-limiting resistor and the input end of the voltage divider unit are both connected to the input end of the main switching circuit through the second diode. The other end of the regulating capacitor is connected to the high-voltage power supply ground. The input end of the RC series unit is connected to the input end of the main switching circuit, and the output end is connected to the high-voltage power supply ground.

[0021] In some embodiments, the intelligent electronic DC contactor further includes:

[0022] An isolation feedback circuit is provided, wherein the input terminal of the isolation feedback circuit is connected to the high-voltage side drive circuit, and the output terminal is used to connect to the low-voltage side controller.

[0023] The high-voltage side drive circuit is also used to collect the voltage drop of the switching transistor in the main circuit to detect whether any one or more of overcurrent, short circuit and overload have occurred, and output a corresponding detection signal when at least one of them occurs;

[0024] The isolation feedback circuit is used to receive the detection signal and isolate it for feedback to the controller.

[0025] In some embodiments, the isolation feedback circuit includes a second optocoupler, a second Zener diode, a third diode, and third to sixth resistors;

[0026] One end of the third resistor is used to connect to the power supply voltage, and the other end is connected to the cathode of the second Zener diode and one end of the fourth resistor, respectively. The anode of the second Zener diode is connected to the cathode of the third diode and the anode of the emitter side of the second optocoupler, respectively.

[0027] The other end of the fourth resistor is connected to the detection signal output terminal of the high-voltage side drive circuit, the anode of the third diode, and the cathode of the second optocoupler, respectively.

[0028] The receiver-side collector of the second optocoupler is used to connect to a preset operating voltage. The emitter is connected to one end of the fifth resistor and the sixth resistor, respectively. The other end of the fifth resistor is connected to the low-voltage side power ground, and the other end of the sixth resistor is used to connect to the controller on the low-voltage side.

[0029] In some embodiments, the intelligent electronic DC contactor further includes a fuse, one end of which is connected to the input terminal of the main switching circuit, and the other end is used to connect to the DC power supply.

[0030] Secondly, embodiments of this application also provide an electrical device, the electrical device comprising: a microprocessor and the aforementioned intelligent electronic DC contactor;

[0031] The controller is used to input switch control signals to the intelligent electronic DC contactor;

[0032] The intelligent electronic DC contactor is used to connect to DC power and control the output state of the connected DC power according to the switch control signal.

[0033] The embodiments of this application have the following beneficial effects:

[0034] The intelligent electronic DC contactor of this application receives the low-voltage side voltage through an isolation voltage conversion circuit and performs isolation conversion on the low-voltage side voltage to obtain the high-voltage side drive voltage. An input isolation circuit is used to detect the switch control signal on the low-voltage side and outputs the switch control signal to the high-voltage side in isolation. Then, when the high-voltage side drive circuit receives the switch control signal, it controls the output of the drive voltage to drive the switching transistors to turn on and off. Finally, the main switch circuit drives each switching transistor to synchronously turn on or off according to the drive voltage, thereby controlling the output state of the connected DC power. Compared to mechanical contactors, the intelligent electronic DC contactor of this application has controllability and high reliability, and is almost unaffected by external environmental factors such as temperature, humidity, and salinity. Furthermore, it easily achieves voltage, current, and temperature information acquisition, as well as overcurrent protection and short-circuit protection functions. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 A schematic diagram of a smart electronic DC contactor according to an embodiment of this application is shown;

[0037] Figure 2 A first circuit diagram of an intelligent electronic DC contactor according to an embodiment of this application is shown;

[0038] Figure 3 This paper shows a schematic diagram of the two-series and two-parallel switching unit of the intelligent electronic DC contactor according to an embodiment of this application;

[0039] Figure 4 A second circuit diagram of the intelligent electronic DC contactor according to an embodiment of this application is shown;

[0040] Figure 5 This paper shows another structural schematic diagram of an intelligent electronic DC contactor according to an embodiment of this application.

[0041] Explanation of key component symbols:

[0042] 100 - Intelligent electronic DC contactor; 110 - Isolation voltage conversion circuit; 120 - Input isolation circuit; 130 - High voltage side drive circuit; 140 - Switching main circuit. Detailed Implementation

[0043] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0044] The components of the embodiments of this application described and illustrated in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0045] In the following, the terms “comprising,” “having,” and their cognates, which may be used in various embodiments of this application, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as excluding, firstly, the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more features, numbers, steps, operations, elements, components, or combinations thereof.

[0046] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0047] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. Terms (such as those defined in commonly used dictionaries) shall be interpreted as having the same meaning as in their contextual meaning in the relevant technical field and shall not be construed as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.

[0048] Please refer to Figure 1This is a schematic diagram of a structure of the intelligent electronic DC contactor 100 proposed in an embodiment of this application. Exemplarily, the intelligent electronic DC contactor 100 includes an isolation voltage conversion circuit 110, an input isolation circuit 120, a high-voltage side drive circuit 130, and a main switching circuit 140. The input terminal of the isolation voltage conversion circuit 110 is used to connect to the low-voltage side voltage V1, and its output terminal is connected to the input isolation circuit 120. The high-voltage side drive circuit 130 is connected to the output terminals of the isolation voltage conversion circuit 110 and the input isolation circuit 120. The input terminal of the main switching circuit 140 is used to connect to DC power (corresponding to...). Figure 1 The Vin_DC output terminal is used to output direct current (corresponding to...). Figure 1 The Vout_DC control terminal is connected to the output terminal of the high-voltage side drive circuit 130.

[0049] The aforementioned direct current can be various types of DC signals, especially high-voltage DC signals of up to 100 volts or more. It can be understood that the intelligent electronic DC contactor 100 is a device used for switching and controlling DC power, equivalent to an electronic switch, and is installed in the power supply line where the DC power is located, thereby controlling the connection or disconnection of the DC power supply line.

[0050] In this embodiment, the isolation voltage conversion circuit 110 is mainly used to isolate and convert the low-voltage side voltage V1 to obtain the high-voltage side driving voltage V2; the input isolation circuit 120 is used to detect the switch control signal on the low-voltage side and isolate and output the detected switch control signal to the high-voltage side; the high-voltage side driving circuit 130 is used to allow the high-voltage side driving voltage output when the switch control signal SW_ARM is received, so as to drive the switching transistor to turn on or off; the main switching circuit 140 is used to drive each switching transistor in the main switching circuit 140 to turn on or off synchronously according to the driving voltage, thereby controlling the output state of the connected DC power. In addition, the isolation voltage conversion circuit 110 is also used to isolate the power supply voltage required by the high-voltage side circuit. The power supply voltage on the low-voltage side and the driving voltage on the high-voltage side may be equal or unequal, which is not limited here.

[0051] It is understood that the intelligent electronic DC contactor 100 mainly includes a logic control section and a main switching circuit section capable of carrying large currents or large voltages. Especially when the voltage of the DC current flowing through it is large, the switching transistor drive voltage required by the main switching circuit section is also relatively large. In this embodiment, the voltage signal output by the logic control section is called the low-voltage side voltage. For example, the isolation voltage conversion circuit 110 mentioned above is connected to the low-voltage side voltage. The switching transistor drive voltage required by the main circuit section is called the high-voltage side drive voltage.

[0052] To better understand the intelligent electronic DC contactor 100, the various components of the intelligent electronic DC contactor 100 are described in detail below.

[0053] In this embodiment, the isolation voltage conversion circuit 110 is mainly used to achieve voltage isolation conversion between the low-voltage side and the high-voltage side, thus preventing the connected high-voltage DC power from affecting the normal operation of the low-voltage side control logic. In one implementation, such as Figure 2 As shown, the isolated voltage conversion circuit 110 can be implemented using an isolation chip U3. The input terminal of the isolation chip U3 is connected to the low-voltage side voltage V1, while the output terminal is connected to the high-voltage side driving voltage V2. For example, if the driving chip U2 in the high-voltage side driving circuit 130 requires an operating voltage of 15V, then it can convert the output to 15V. Correspondingly, some filter capacitors can also be set at the input and output terminals of the isolation chip U3, such as… Figure 2 The capacitors C7 to C10 shown reduce power supply ripple, etc. Alternatively, the isolation voltage conversion circuit 110 can also be implemented using an isolation transformer, etc.

[0054] In this embodiment, the input isolation circuit 120 is mainly used to detect the switch control signal SW_ARM output by the controller located on the low-voltage side, and isolate and output the switch control signal SW_ARM to the high-voltage side drive circuit 130 on the high-voltage side. It can be understood that the low-voltage side switch control signal SW_ARM can be output by a controller (such as an ARM) located on the low-voltage side. For example, when it is necessary to control the DC power to be turned on, an on control signal is issued; conversely, when it is necessary to control the DC power to be turned off, an off control signal is issued. In addition, periodic pulse signals can also be issued.

[0055] In one implementation, such as Figure 2As shown, the input isolation circuit 120 includes a first optocoupler U1, a first Zener diode D3, a first RC parallel unit, and a second RC parallel unit. The first RC parallel unit can be composed of a resistor R3 and a capacitor C1 connected in parallel, and the second RC parallel unit can be composed of a resistor R11 and a capacitor C4 connected in parallel. Specifically, one end of the first RC parallel unit is connected to the transmitting side of the first optocoupler U1 and is also used to receive the switch control signal SW_ARM; the other end is connected to the low-voltage side power ground GND. Optionally, one end of the first RC parallel unit can also be connected to the controller via a current-limiting resistor R1. The receiving-side collector of the first optocoupler U1 is used to connect to the high-voltage side power supply voltage, and the emitter, after passing through the first Zener diode D3, is connected to the high-voltage side drive circuit 130 and one end of the second RC parallel unit. The other end of the second RC parallel unit is connected to the high-voltage side power ground. It is understandable that when a switch control signal SW_ARM is generated, the transmitting side of the first optocoupler U1 can be turned on. Then, after the receiving side of the first optocoupler U1 receives the optical signal, it generates a corresponding control signal which is input to the high-voltage side drive circuit 130. It is also understandable that, for ease of distinguishing between different power grounds, the low potential referenced by the logic control section on the low-voltage side is referred to as the low-voltage side power ground (corresponding to...). Figure 2 V1-), and the low potential referenced by the high-voltage side drive section is called the high-voltage side power ground (corresponding to V1-). Figure 2 (V2- in the middle).

[0056] In this embodiment, the high-voltage side drive circuit 130 is mainly used to control the output state of the drive voltage required by each switching transistor in the main circuit. In addition, the high-voltage side drive circuit 130 is also used to collect the voltage drop of the switching transistors in the main circuit to detect whether overcurrent, short circuit, etc. occur, and output corresponding detection signals when overcurrent, short circuit, etc. occur, and provide corresponding timely protection for the main circuit where DC power is located.

[0057] In one implementation, such as Figure 2As shown, the high-voltage side drive circuit 130 includes a floating drive chip U2, an adjusting capacitor C3, a current-limiting resistor R2, a first diode D1, a second diode D2, a voltage divider unit, and an RC series unit. The floating drive chip U2 includes multiple functional pins. The voltage divider unit consists of two series-connected voltage divider resistors R4 and R10, and the RC series unit consists of a resistor R7 and a capacitor C2. Specifically, the chip power supply pin VCC of the floating drive chip U2 is used to connect to the required operating voltage (e.g., 15V). The signal input pin IN is connected to the input isolation circuit 120. The drive power supply pin VB is used to connect to the high-voltage side drive voltage V2 via the first diode D1. The drive output pin HO is connected to the control terminal of the main switching circuit 140 and the current-limiting resistor R2, respectively. The current sampling pin CS is connected to the voltage divider output terminal of the voltage divider unit and the adjusting capacitor C3, respectively. Furthermore, other pins of the floating drive chip U2 can be configured according to requirements. For example, the overcurrent detection output pin FAULT can be used to connect to a corresponding isolation feedback circuit. The other end of the current-limiting resistor R2 and the input end of the voltage divider unit are both connected to the input end of the main switching circuit 140 through the second diode D2. The other end of the regulating capacitor C3 is connected to the high-voltage power supply ground. The input end of the RC series unit is connected to the input end of the main switching circuit 140, and the output end is connected to the high-voltage power supply ground.

[0058] The overcurrent point can be adjusted by regulating the ratio of resistors R10 and R4 in the voltage divider unit. Capacitor C3 serves two purposes: filtering and adjusting the capacitance of the capacitive load, which can cause inrush current when the MOSFET is turned on, potentially leading to false protection. For example, this floating drive chip can be implemented using a driver chip such as the IR2127xx series, which integrates functions like bootstrap voltage boost, drive output, and current sampling. Alternatively, it can be implemented using discrete circuits with corresponding functions; this is not a limitation. The floating drive chip achieves floating voltage boost by adjusting the potential of the power supply ground on the high-voltage side to obtain a floating drive voltage. This means the voltage difference input to the MOSFET remains constant, only the potential reference changes. This allows the intelligent electronic DC contactor 100 to be applicable to various DC on / off control scenarios with different voltage levels, increasing its applicability.

[0059] It should be understood that the connection method and number of resistors are not limited in this embodiment. For example, multiple resistors can be connected in series, in parallel, or in a combination of series and parallel. The specific method can be determined according to the actual required resistor size.

[0060] In this embodiment, the main switching circuit 140 includes at least two switching transistors connected in series in the line. The main switching circuit 140 is used to control the on / off state of the connected DC power supply line by driving each switching transistor to conduct or cut off synchronously. Taking two switching transistors as an example, these two switching transistors are connected in series and share a common driving signal to achieve synchronous control. This also prevents reverse connection of DC power input and output, improving circuit reliability and fault tolerance.

[0061] In one implementation, such as Figure 2 As shown, the main switching circuit 140 includes a first switching unit and a second switching unit. The first switching unit includes a first switching transistor Q1, and the second switching unit includes a second switching transistor Q2. Specifically, the control terminals of both the first and second switching transistors Q1 and Q2 are connected to the drive output pin of the high-voltage side drive circuit 130. The first signal terminal of the first switching transistor Q1 serves as the first terminal of the first switching unit, used to connect to DC power. The second signal terminal of the first switching transistor Q1 is connected to the second signal terminal of the second switching transistor Q2. The first signal terminal of the second switching transistor Q2 serves as the first terminal of the second switching unit, used to output DC power. In addition to a switching transistor, each switching unit also includes a first resistor (such as...). Figure 2 R5 and R12 in the middle), the second resistor (such as Figure 2 R8 and R13 in the diagram) and bidirectional diodes (such as Figure 2 In the circuit, D4 and D6 are connected to the control terminal of each switching transistor via the first resistor in its respective switching unit to the drive output pin of the high-voltage side drive circuit 130. The second resistor and the bidirectional diode are connected in parallel, with one end connected to the control terminal of the switching transistor and the other end connected to the second signal terminal of the switching transistor. Optionally, when DC power is applied, a fuse F1 can be connected in series at the input terminal of the main switching circuit 140 for protection.

[0062] In another embodiment, in addition to the two switching units, the main switching circuit 140 also includes two more switching units, thus consisting of four switching units. Specifically, it adopts a two-series, two-parallel structure, such as... Figure 3 As shown. Considering that connecting two MOSFETs in series will increase conduction losses, as an alternative, two MOSFETs can be connected in parallel. Since the two parallel paths can shunt current and have lower internal resistance, this can not only reduce the operating pressure of each switching transistor, but also reduce the power consumption caused by internal resistance, thereby solving the heat dissipation problem.

[0063] Exemplarily, the main switching circuit 140 also includes a third switching unit and a fourth switching unit, wherein the third switching unit includes a third switching transistor Q3 and the fourth switching unit includes a fourth switching transistor Q4; specifically, as Figure 4As shown, the control terminals of the third switch Q3 and the fourth switch Q4 are both connected to the drive output pin, meaning that the four switches Q1 to Q4 share a single drive signal. The first signal terminal of the third switch Q3 is connected to the first signal terminal of the first switch Q1, and the second signal terminal of the third switch Q3 is connected to the first signal terminal of the first switch Q1. The first signal terminals of the fourth switch Q4 and the second signal terminals of the second switch Q2 are connected to each other. In other words, the first and third switch units are symmetrically arranged, and the second and fourth switch units are also symmetrically arranged.

[0064] Each of the aforementioned switching transistors Q1 to Q4 can be implemented using a high-power switching device such as a MOSFET or IGBT with the same structure. For example, taking a MOSFET as an example, the two switching transistors are connected in a common-source configuration. Specifically, the drain of the MOSFET serves as the first signal terminal of the switching transistor, the source of the MOSFET serves as the second signal terminal of the switching transistor, and the gate of the MOSFET serves as the control terminal of the switching transistor.

[0065] Based on such Figure 2 or Figure 3 As an optional configuration, the intelligent electronic DC contactor 100, as shown in the diagram, further includes an isolation feedback circuit. The input of the isolation feedback circuit is connected to the high-voltage side drive circuit 130, and the output of the isolation feedback circuit is connected to the controller. The high-voltage side drive circuit 130 is also used to acquire the voltage drop of the switching transistors in the main circuit. Taking a MOSFET as an example, the voltage drop between the drain and source of the MOSFET can be used to detect whether any one or more of overcurrent, short circuit, or overload conditions occur. When at least one of these conditions occurs, a corresponding detection signal is output. The isolation feedback circuit receives the detection signal and isolates it to feed it back to the controller, enabling the controller to perform corresponding operations.

[0066] In one implementation, such as Figure 4As shown, the isolation feedback circuit includes a second optocoupler U4, a second Zener diode D8, a third diode D9, and third to sixth resistors (i.e., R16 to R19). Specifically, one end of the third resistor R16 is connected to the power supply voltage, and the other end is connected to the cathode of the second Zener diode D8 and one end of the fourth resistor R18, respectively. The anode of the second Zener diode D8 is connected to the cathode of the third diode D9 and the anode of the second optocoupler U4 on the emitter side, respectively. The other end of the fourth resistor R18 is connected to the detection signal output terminal of the high-voltage side drive circuit 130 (such as the overcurrent detection output pin FAULT of the floating drive chip U2), the anode of the third diode D9, and the cathode of the second optocoupler U4 on the emitter side, respectively. The collector on the receiver side of the second optocoupler U4 is connected to a preset operating voltage (such as 5V), and the emitter is connected to one end of the fifth resistor R17 and the sixth resistor R19, respectively. The other end of the fifth resistor R17 is connected to the low-voltage side power supply ground, and the other end of the sixth resistor R19 is connected to the controller on the low-voltage side. Furthermore, it also includes a ground resistance R20 connected to the other end of the sixth resistor R19, for protection purposes, etc.

[0067] In this embodiment, by using a main switching circuit 140 composed of at least two series-connected switching transistors, all switching transistors can not only share a single drive signal, but also facilitate synchronous control of all switching transistors, thereby achieving reliable control of the output state of the connected DC power. In addition, by using a two-series-two-parallel scheme, the internal resistance loss caused by the series connection of switching transistors can be reduced while achieving reliable control, thereby further reducing system power consumption.

[0068] As an alternative solution, such as Figure 5 As shown, the intelligent electronic DC contactor also includes an input voltage detection circuit for detecting DC power input, an output voltage detection circuit and a current detection circuit for detecting DC power output, and a temperature detection circuit. These circuits are all connected to a controller, enabling the controller to process the detected information accordingly, thereby achieving overcurrent protection, secondary overload protection, and overtemperature protection for the electrical equipment. The intelligent electronic DC contactor also supports programmable overload protection settings. Further optionally, the intelligent electronic DC contactor 100 may also include an indicator module for indicating the corresponding status, such as LEDs or a buzzer. In addition, the intelligent electronic DC contactor can also achieve data communication with external devices (such as a control panel) via a communication module. For example, it can upload various collected data and log information to achieve data synchronization, thus providing a foundation for intelligent power supply control.

[0069] Furthermore, this application also proposes an electrical device, such as various load devices that require DC power input. Exemplarily, this electrical device includes the intelligent electronic DC contactor 100 described in the above embodiments; wherein the intelligent electronic DC contactor 100 is used to connect to DC power and control the output state of the connected DC power. It is understood that the options regarding the intelligent electronic DC contactor 100 in the above embodiments also apply to this embodiment, and will not be described again here.

[0070] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A smart electronic DC contactor, characterized in that, include: An isolation voltage conversion circuit is used to receive a low-voltage side voltage, isolate and convert the low-voltage side voltage to obtain a high-voltage side driving voltage; An input isolation circuit is connected to the output terminal of the isolation voltage conversion circuit. It is used to detect the switching control signal on the low-voltage side and isolate and output the switching control signal to the high-voltage side. A high-voltage side drive circuit, connected to the output terminal of the isolation voltage conversion circuit and the input isolation circuit, is used to control the output of the drive voltage when the switch control signal is received; The main switching circuit has an input terminal for receiving DC power, an output terminal for outputting DC power, and a control terminal connected to the high-voltage side drive circuit. The main switching circuit is used to drive each switching transistor in the main switching circuit to be synchronously turned on or off according to the drive voltage, thereby controlling the on / off state of the connected DC power supply line. The main switching circuit includes a first switching unit and a second switching unit. The first switching unit includes a first switching transistor, and the second switching unit includes a second switching transistor. The control terminals of the first switching transistor and the second switching transistor are both connected to the drive output pin of the high-voltage side drive circuit. The first signal terminal of the first switching transistor is used to connect to the DC power, the second signal terminal of the first switching transistor is connected to the second signal terminal of the second switching transistor, and the first signal terminal of the second switching transistor is used to output the DC power.

2. The intelligent electronic DC contactor according to claim 1, characterized in that, The main switching circuit further includes a third switching unit and a fourth switching unit, wherein the third switching unit includes a third switching transistor and the fourth switching unit includes a fourth switching transistor; The control terminals of the third and fourth switching transistors are both connected to the drive output pin. The third switching transistor is connected to the first signal terminal of the first switching transistor, and the third switching transistor is connected to the second signal terminal of the first switching transistor. The fourth switching transistor is connected to the first signal terminal of the second switching transistor, and the fourth switching transistor is connected to the second signal terminal of the second switching transistor.

3. The intelligent electronic DC contactor according to claim 1 or 2, characterized in that, Each of the switching units further includes a first resistor, a second resistor, and a bidirectional diode; The control terminal of each of the switching transistors is connected to the drive output pin via the first resistor in its respective switching unit. The second resistor and the bidirectional diode are connected in parallel, with one end connected to the control terminal of the switching transistor and the other end connected to the second signal terminal of the switching transistor.

4. The intelligent electronic DC contactor of claim 1, wherein, The input isolation circuit includes a first optocoupler, a first Zener diode, a first RC parallel unit, and a second RC parallel unit; One end of the first RC parallel unit is connected to the transmitting side of the first optocoupler and is also used to connect to the controller to access the switch control signal, and the other end is connected to the low-voltage side power ground. The receiver-side collector of the first optocoupler is used to connect to the high-voltage side power supply voltage. The emitter is connected to the high-voltage side driving circuit and one end of the second RC parallel unit after passing through the first Zener diode. The other end of the second RC parallel unit is connected to the high-voltage side power supply ground.

5. The intelligent electronic DC contactor of claim 4, wherein, The high-voltage side drive circuit includes a floating drive chip, an adjusting capacitor, a current-limiting resistor, first and second diodes, a voltage divider unit, and an RC series unit. The floating drive chip includes multiple functional pins. The floating drive chip has a chip power supply pin for connecting to the supply voltage, a signal input pin for connecting to the input isolation circuit, a drive power supply pin for connecting to the drive voltage via the first diode, a drive output pin for connecting to the control terminal of the main switching circuit and the current limiting resistor, and a current sampling pin for connecting to the voltage divider output terminal of the voltage divider unit and the regulating capacitor. The other end of the current-limiting resistor and the input end of the voltage divider unit are both connected to the input end of the main switching circuit through the second diode. The other end of the regulating capacitor is connected to the high-voltage power supply ground. The input end of the RC series unit is connected to the input end of the main switching circuit, and the output end is connected to the high-voltage power supply ground.

6. The intelligent electronic DC contactor of claim 1, wherein, Also includes: An isolation feedback circuit is provided, wherein the input terminal of the isolation feedback circuit is connected to the high-voltage side drive circuit, and the output terminal is used to connect to the controller. The high-voltage side drive circuit is also used to collect the voltage drop of the switching transistor in the main circuit to detect whether any one or more of overcurrent, short circuit and overload have occurred, and output a corresponding detection signal when at least one of them occurs; The isolation feedback circuit is used to receive the detection signal and isolate it for feedback to the controller.

7. The intelligent electronic DC contactor of claim 6, wherein, The isolation feedback circuit includes a second optocoupler, a second Zener diode, a third diode, and third to sixth resistors. One end of the third resistor is used to connect to the power supply voltage, and the other end is connected to the cathode of the second Zener diode and one end of the fourth resistor, respectively. The anode of the second Zener diode is connected to the cathode of the third diode and the anode of the emitter side of the second optocoupler, respectively. The other end of the fourth resistor is connected to the detection signal output terminal of the high-voltage side drive circuit, the anode of the third diode, and the cathode of the second optocoupler, respectively. The receiver-side collector of the second optocoupler is used to connect to a preset operating voltage. The emitter is connected to one end of the fifth resistor and the sixth resistor, respectively. The other end of the fifth resistor is connected to the low-voltage side power ground, and the other end of the sixth resistor is used to connect to the controller on the low-voltage side.

8. The intelligent electronic DC Contactor according to any one of claims 1 to 2, characterized in that, Also includes: A fuse, one end of which is connected to the input terminal of the main circuit of the switch, and the other end is used to connect to the DC power supply.

9. An electrical device, characterized by include: The intelligent electronic DC contactor as described in any one of claims 1 to 8; the intelligent electronic DC contactor is used to connect to DC power and control the on / off state of the connected DC power supply line.

Images