High-voltage direct-current bus protection circuit and power controller

Abstract

The utility model discloses a high-voltage DC bus protection circuit and a power controller. The high-voltage direct-current bus protection circuit comprises a voltage division module, a first protection module, a second protection module and a switch module, the direct-current bus comprises a first bus and a second bus; the first protection module is connected to a first bus in series, the first end of the voltage dividing module is connected with the first bus, the second end of the voltage dividing module is connected with the control end of the switch module, the first end of the switch module is connected with power supply voltage, the second end of the switch module outputs a first detection signal, and the third end of the voltage dividing module is connected with the first end of the second protection module. The second end of the second protection module is connected with the third end of the switch module, the third end of the second protection module and the fourth end of the second protection module are both connected with the second bus, and the first protection module is used for acting according to the first detection signal. According to the technical scheme of the embodiment of the utility model, the safety and the reliability of the equipment can be improved.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, and in particular to a high-voltage DC bus protection circuit and a power controller. Background Technology

[0002] Reverse connection of the DC bus in a controller can damage the controller and, in severe cases, cause fires, explosions, and other safety accidents, posing a threat to personnel and equipment safety. Therefore, how to detect DC bus reverse connection and how to protect against it are urgent technical problems that need to be solved. Utility Model Content

[0003] This invention provides a high-voltage DC bus protection circuit and a power controller to improve the safety and reliability of equipment.

[0004] According to one aspect of this utility model, a high-voltage DC bus protection circuit is provided, including a voltage divider module, a first protection module, a second protection module, and a switch module; the DC bus includes a first bus and a second bus.

[0005] The first protection module is connected in series with the first busbar. The first end of the voltage divider module is connected to the first busbar, and the second end of the voltage divider module is connected to the control terminal of the switch module. The first end of the switch module is connected to the power supply voltage, and the second end of the switch module outputs a first detection signal. The third end of the voltage divider module is connected to the first end of the second protection module, and the second end of the second protection module is connected to the third end of the switch module. The third end and the fourth end of the second protection module are both connected to the second busbar. The first protection module is used to operate according to the first detection signal.

[0006] Optionally, the high-voltage DC bus protection circuit further includes a control module; the first protection module includes a relay.

[0007] The control module is connected to the second terminal of the switch module and the relay respectively, and the control module is used to control the operation of the relay according to the first detection signal.

[0008] Optionally, the second protection module includes a first protection unit and a second protection unit;

[0009] The first end of the first protection unit is connected to the third end of the voltage divider module, and the second end of the first protection unit is connected to the second busbar; the first end of the second protection unit is connected to the third end of the switch module, and the second end of the second protection unit is connected to the second busbar.

[0010] Optionally, the first protection unit includes a first diode, and the second protection unit includes a second diode;

[0011] The first terminal of the first diode is connected to the third terminal of the voltage divider module, and the second terminal of the first diode is connected to the second busbar; the first terminal of the second diode is connected to the third terminal of the switch module, and the second terminal of the second diode is connected to the second busbar.

[0012] The voltage ratings of the first diode and the second diode are greater than the voltage of the DC bus.

[0013] Optionally, the voltage divider module includes at least two resistors, which are connected in series between the first busbar and the first terminal of the first protection module.

[0014] Optionally, the switch module includes a first switch unit, a drive unit, a pull-up unit, and a pull-down unit;

[0015] The first end of the drive unit is connected to the third end of the voltage divider module, the second end of the drive unit is connected to the control end of the first switch unit, the first end of the first switch unit is connected to the first end of the pull-up unit, the second end of the pull-up unit is connected to the power supply voltage, the second end of the first switch unit is connected to the first end of the pull-down unit, and the second end of the pull-down unit is connected to the control end of the first switch unit.

[0016] Optionally, the first switching unit includes a first transistor, the driving unit includes a first resistor, the pull-up unit includes a second resistor, and the pull-down unit includes a third resistor;

[0017] The first end of the first resistor is connected to the third end of the voltage divider module, the second end of the first resistor is connected to the control electrode of the first transistor, the first electrode of the first transistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the power supply voltage, the second electrode of the first transistor is connected to the first end of the third resistor, and the second end of the third resistor is connected to the control electrode of the first transistor.

[0018] Optionally, the high-voltage DC bus protection circuit also includes a digital isolation module;

[0019] The first end of the digital isolation module is connected to the second end of the switch module, and the digital isolation module is used to output a second detection signal based on the first detection signal.

[0020] According to another aspect of the present invention, a power controller is provided, including the high-voltage DC bus protection circuit provided in any embodiment of the present invention; the power controller further includes a bus capacitor and a pre-charge module;

[0021] The first end of the bus capacitor is connected to the first bus, and the second end of the bus capacitor is connected to the second bus; the first end of the pre-charge module is connected to the first bus, and the second end of the pre-charge module is connected to the first end of the bus capacitor.

[0022] Optionally, the pre-charging module includes a third protection unit and a current limiting unit;

[0023] The first end of the third protection unit is connected to the first busbar, the second end of the third protection unit is connected to the first end of the current limiting unit, and the second end of the current limiting unit is connected to the first end of the busbar capacitor.

[0024] The third protection unit includes a third diode, the first terminal of which is connected to the first busbar, and the second terminal of which is connected to the current limiting unit.

[0025] The current limiting unit includes at least two resistors, which are connected between the first terminal of the third diode and the first terminal of the bus capacitor.

[0026] The technical solution of this utility model embodiment, by setting a voltage divider module, a switch module, a first protection module, and a second protection module, allows the voltage divider module to drive the switch module after dividing the voltage of the high-voltage DC bus, thereby the switch module outputting a first detection signal. Because the voltage of the DC high-voltage bus differs when it is connected in the correct direction and in reverse, the second protection module is either on or off, resulting in different voltage divisions output by the voltage divider module. Consequently, the voltage at the control terminal of the first switch module also differs, leading to different first detection signals output by the second terminal of the first switch module. Therefore, the actions taken by the first protection module in response to the first detection signal also differ. Thus, this utility model embodiment can determine whether the high-voltage DC bus is reverse-connected based on the first detection signal and control the first protection module to perform protective actions when reverse-connected, thereby avoiding damage to electronic equipment caused by high-voltage DC bus reverse connection, improving equipment safety and reliability, and ultimately enhancing personnel safety.

[0027] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of a high-voltage DC bus protection circuit according to an embodiment of the present utility model;

[0030] Figure 2 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present utility model;

[0031] Figure 3 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present utility model;

[0032] Figure 4 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present utility model;

[0033] Figure 5 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present utility model;

[0034] Figure 6 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present utility model;

[0035] Figure 7 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present utility model;

[0036] Figure 8 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present utility model;

[0037] Figure 9 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present utility model;

[0038] Figure 10 This is a schematic diagram of a power controller according to an embodiment of the present utility model;

[0039] Figure 11 This is a schematic diagram of another power controller provided according to an embodiment of the present utility model. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0041] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and their variations, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0042] Figure 1 This is a schematic diagram of a high-voltage DC bus protection circuit according to an embodiment of the present invention, with reference to... Figure 1 The high-voltage DC bus protection circuit includes a voltage divider module 10, a first protection module 20, a second protection module 30, and a switch module 40. The DC bus includes a first bus L1 and a second bus L2. The first protection module 20 is connected in series with the first bus L1. The first end of the voltage divider module 10 is connected to the first bus L1, and the second end of the voltage divider module 10 is connected to the control terminal of the switch module 40. The first end of the switch module 40 is connected to the supply voltage VCC, and the second end of the switch module 40 outputs a first detection signal DC_EN. The third end of the voltage divider module 10 is connected to the first end of the second protection module 30, and the second end of the second protection module 30 is connected to the third end of the switch module 40. The third end and the fourth end of the second protection module 30 are both connected to the second bus L2. The first protection module 20 is used to operate according to the first detection signal DC_EN.

[0043] The first detection signal DC_EN can be either a high-level signal or a low-level signal, depending on the conduction state of the switch module 40. For example, when the switch module 40 is in the conduction state, the first detection signal DC_EN is a low-level signal; when the switch module 40 is in the off state, the first detection signal DC_EN is a high-level signal. The operation of the first protection module 20 can include engaging or disengaging, depending on the high or low level of the first detection signal DC_EN. For example, when the first detection signal DC_EN is a low-level signal, the first protection module 20 engages in response to the low-level signal; when the first detection signal DC_EN is a high-level signal, the first protection module 20 disengages in response to the low-level signal. It can be understood that when the first protection module 20 is engaged, the DC bus is in the conduction state; when the first protection module 20 is disengaged, the DC bus is in the disconnection state.

[0044] Specifically, when the high-voltage DC bus is in the positive connection state, the voltage divider module 10 divides the voltage across the DC bus and drives the switch module 40. At this time, the switch module 40 is in the conducting state, so the first detection signal DC_EN output by the switch module 40 is a low level signal, the first protection module 20 is activated, the high-voltage DC bus is powered on, and it normally supplies power to the equipment.

[0045] When the high-voltage DC bus is in reverse connection, the second protection module 30 is in the off state, and the voltage divider circuit of the voltage divider module 10 is cut off. At this time, the voltage divider module 10 cannot drive the switch module 40 normally, and the switch module 40 is in the off state. As a result, the first detection signal DC_EN output by the switch module 40 is a high-level signal, the first protection module 20 is released, and the DC current on the high-voltage DC bus cannot flow into the subsequent circuit, protecting the subsequent devices from damage.

[0046] The technical solution of this utility model embodiment, by setting a voltage divider module, a switch module, a first protection module, and a second protection module, allows the voltage divider module to drive the switch module after dividing the voltage of the high-voltage DC bus, thereby the switch module outputting a first detection signal. Because the voltage of the DC high-voltage bus differs when it is connected in the correct direction and in reverse, the second protection module is either on or off, resulting in different voltage divisions output by the voltage divider module. Consequently, the voltage at the control terminal of the first switch module also differs, leading to different first detection signals output by the second terminal of the first switch module. Therefore, the actions performed by the first protection module in response to the first detection signal also differ. Thus, this utility model embodiment can determine whether the high-voltage DC bus is reverse-connected based on the first detection signal and control the first protection module to perform protective actions when reverse-connected, thereby avoiding damage to electronic equipment caused by high-voltage DC bus reverse connection, improving equipment safety and reliability, and ultimately enhancing personnel safety.

[0047] Figure 2 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present invention, with reference to... Figure 2 Optionally, based on the above embodiments, the high-voltage DC bus protection circuit further includes a control module 100; the first protection module 20 includes a relay W1; the control module 100 is connected to the second terminal of the switch module 40 and the relay W1 respectively, and the control module 100 is used to control the operation of the relay W1 according to the first detection signal DC_EN.

[0048] The control module 100 may include a microcontroller.

[0049] Specifically, the control module 100 outputs a control signal based on the high or low level of the first detection signal DC_EN, and the relay W1 responds to the control signal to operate. For example, the control module 100 outputs a first control signal based on the low level of the first detection signal DC_EN, and the relay W1 responds to the first control signal to engage; the control module 100 outputs a second control signal based on the high level of the first detection signal DC_EN, and the relay W1 responds to the second control signal to disengage. Here, the relay controls the on / off state of the DC bus through the opening and closing of physical contacts, providing high reliability. Mechanical relays can withstand many switching operations, have a long service life, and are suitable for applications requiring frequent switching. Furthermore, the control method and control circuit of the relay are simple.

[0050] It is understood that in other embodiments, the first protection module 20 may also be an electronic switch.

[0051] Figure 3 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present invention, with reference to... Figure 3 Based on the above embodiments, optionally, the second protection module 30 includes a first protection unit 31 and a second protection unit 32; the first end of the first protection unit 31 is connected to the third end of the voltage divider module 10, and the second end of the first protection unit 31 is connected to the second bus L2; ​​the first end of the second protection unit 32 is connected to the third end of the switch module 40, and the second end of the second protection unit 32 is connected to the second bus L2.

[0052] The first protection unit 31 is used to cut off the voltage divider circuit of the voltage divider module 10 when the high-voltage DC bus is in reverse connection; the second protection unit 32 is used to ensure that the switch module 40 is not damaged when the high-voltage DC bus is in reverse connection.

[0053] Figure 4 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present invention, with reference to... Figure 4 Based on the above embodiments, optionally, the first protection unit 31 includes a first diode D1, and the second protection unit 32 includes a second diode D2; the first terminal of the first diode D1 is connected to the third terminal of the voltage divider module 40, and the second terminal of the first diode D1 is connected to the second bus L2; ​​the first terminal of the second diode D2 is connected to the third terminal of the switch module 40, and the second terminal of the second diode D2 is connected to the second bus L2; ​​wherein, the withstand voltage of the first diode D1 and the withstand voltage of the second diode D2 are greater than the voltage of the DC bus.

[0054] Combination Figure 3 and Figure 4Specifically, when the high-voltage DC bus is in the positive connection state, the first diode D1 is turned on, and the voltage divider module 10 divides the voltage across the DC bus and drives the switch module 40. At this time, the switch module 40 is in the on state, so the first detection signal DC_EN output by the switch module 40 is a low level signal, the first protection module 20 is activated, the high-voltage DC bus is powered on, and it normally supplies power to the equipment.

[0055] When the high-voltage DC bus is in reverse connection, due to the unidirectional conduction characteristic of the first diode D1, the voltage divider circuit of the voltage divider module 10 is cut off. At this time, the voltage divider module 10 cannot drive the switch module 40 normally, and the switch module 40 is in the off state. Therefore, the first detection signal DC_EN output by the switch module 40 is a high-level signal, the first protection module 20 is released, and the DC current on the high-voltage DC bus cannot flow into the subsequent circuit, protecting the subsequent devices from damage. Because of the presence of the second diode D2, and because the withstand voltage of the second diode D2 is greater than the voltage of the high-voltage DC bus, the switch module 40 is guaranteed not to be damaged when the high-voltage DC bus is in reverse connection. Furthermore, because the withstand voltage of the first diode D1 is greater than the voltage of the high-voltage DC bus, the first diode D1 is not damaged when the high-voltage DC bus is in reverse connection.

[0056] Figure 5 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present invention, with reference to... Figure 5 Based on the above embodiments, optionally, the voltage divider module 10 includes at least two resistors, which are connected in series between the first bus L1 and the first terminal of the first protection module 30. This embodiment exemplarily shows that the voltage divider module 10 includes five resistors: a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8, wherein the common connection point of the seventh resistor R7 and the eighth resistor R8 serves as the third terminal of the voltage divider module 10. In other embodiments, the voltage divider module 10 may also use other numbers of resistors; this embodiment does not impose specific limitations.

[0057] Figure 6 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present invention, with reference to... Figure 6Based on the above embodiments, optionally, the switch module 40 includes a first switch unit 41, a drive unit 42, a pull-up unit 43, and a pull-down unit 44; the first end of the drive unit 42 is connected to the third end of the voltage divider module 10, the second end of the drive unit 42 is connected to the control end of the first switch unit 41, the first end of the first switch unit 41 is connected to the first end of the pull-up unit 43, the second end of the pull-up unit 43 is connected to the power supply voltage VCC, the second end of the first switch unit 41 is connected to the first end of the pull-down unit 44, and the second end of the pull-down unit 44 is connected to the control end of the first switch unit 41.

[0058] The first switching unit 41 is used to turn on when the high-voltage DC bus is connected in the correct direction and to turn off when the high-voltage DC bus is connected in the reverse direction. The driving unit 42 is used to drive the first switching unit 41, the pull-up unit 43 is used to limit the current after the first switching unit 41 is turned on, and the pull-down unit 44 is used to provide a bias voltage for the first switching unit 41.

[0059] Figure 7 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present invention, with reference to... Figure 7 Based on the above embodiments, optionally, the first switching unit 41 includes a first transistor Q1, the driving unit 42 includes a first resistor R1, the pull-up unit 43 includes a second resistor R2, and the pull-down unit 44 includes a third resistor R3; the first end of the first resistor R1 is connected to the third end of the voltage divider module 10, the second end of the first resistor R1 is connected to the control electrode of the first transistor Q1, the first electrode of the first transistor Q1 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the power supply voltage VCC, the second electrode of the first transistor Q1 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 is connected to the control electrode of the first transistor Q1.

[0060] The second resistor R2 is the pull-up resistor of the first transistor Q1, used to limit the current after the first transistor Q1 is turned on.

[0061] Combination Figure 6 and Figure 7 Specifically, when the high-voltage DC bus is in the positive connection state, the voltage divider module 10 divides the voltage across the DC bus and drives the first transistor Q1 through the first resistor R1. When the control electrode of the first transistor Q1 receives a high level, it turns on. At this time, the first detection signal DC_EN is pulled low, the first protection module 20 is activated, the high-voltage DC bus is powered on, and it normally supplies power to the equipment.

[0062] When the high-voltage DC bus is in reverse connection, the second protection module 30 is in the off state, and the voltage divider circuit of the voltage divider module 10 is cut off. At this time, the voltage divider module 10 cannot drive the first transistor Q1 normally, and the first transistor Q1 is in the off state. At this time, the first detection signal DC_EN is high level (e.g., VCC), the first protection module 20 is released, and the DC current on the high-voltage DC bus cannot flow into the subsequent circuit, protecting the subsequent devices from damage.

[0063] Figure 8 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present invention, with reference to... Figure 8 Optionally, based on the above embodiments, the high-voltage DC bus protection circuit further includes a digital isolation module 50; the first end of the digital isolation module 50 is connected to the second end of the switch module 40, and the digital isolation module 50 is used to output a second detection signal DI_DC_EN according to the first detection signal DC_EN.

[0064] Digital isolation chips are used to isolate input and output signals, typically using opto-isolation or magnetic isolation.

[0065] Specifically, when the first detection signal DC_EN output by the switching module 40 is low, the digital isolation chip 50 will transmit the first detection signal DC_EN to the output terminal through isolation principles (e.g., through an optocoupler) to output the second detection signal DI_DC_EN. Due to its transmission characteristics, the isolated second detection signal DI_DC_EN will still remain at a low level, thereby ensuring signal integrity and reliability.

[0066] Figure 9 This is a schematic diagram of another high-voltage DC bus protection circuit provided according to an embodiment of the present invention, with reference to... Figure 9 Based on the above embodiments, the working principle of the high voltage DC bus protection circuit will be explained in detail.

[0067] Specifically, when the high-voltage DC bus is in the positive connection state, the first diode D1 conducts. The voltage divider module 10 divides the voltage across the DC bus and drives the first transistor Q1 through the first resistor R1. At this time, the control electrode of the first transistor Q1 is at a high level, and the first transistor Q1 conducts. Furthermore, the conduction voltage of the first transistor Q1 can be adjusted by the voltage divider resistors (fourth resistor R4 - eighth resistor R8). This pulls the first detection signal DC_EN low, and the second detection signal DI_DC_EN output after passing through the digital isolation chip 50 remains low. Further, the digital isolation chip 50 transmits this second detection signal DI_DC_EN to the control module (not shown in the figure). The control module determines that the high-voltage DC bus is in the positive connection based on the low level of the second detection signal DI_DC_EN, and then controls the relay W1 to engage, completing the power-on of the high-voltage DC bus and providing normal power to the equipment.

[0068] When the high-voltage DC bus is in reverse connection, due to the unidirectional conduction characteristic of the first diode D1, there is no voltage drop between the voltage divider resistors (fourth resistor R4 - eighth resistor R8). At this time, the voltage at the control electrode of the first transistor Q1 is less than its threshold voltage. Therefore, the first detection signal DC_EN is high, and the second detection signal DI_DC_EN output after passing through the digital isolation chip 50 is also high. Furthermore, the digital isolation chip 50 transmits this second detection signal DI_DC_EN to the control module (not shown in the figure). The control module determines that the high-voltage DC bus is in reverse connection based on the high level of the second detection signal DI_DC_EN, and then controls the relay W1 to release. The DC current on the high-voltage DC bus cannot flow into the subsequent circuit, protecting the subsequent devices from damage. Due to the presence of the second diode D2, and the fact that the withstand voltage of the second diode D2 is greater than the voltage of the high-voltage DC bus, the switching module 40 is guaranteed not to be damaged when the high-voltage DC bus is in reverse connection. Furthermore, because the withstand voltage of the first diode D1 is greater than the voltage of the high-voltage DC bus, the first diode D1 will not be damaged when the high-voltage DC bus is in reverse connection.

[0069] This utility model embodiment also provides a power controller, including the DC bus protection circuit provided in any of the above embodiments. Therefore, the power controller also has the beneficial effects of any of the above embodiments.

[0070] Figure 10 This is a schematic diagram of a power controller according to an embodiment of the present invention, with reference to... Figure 10Optionally, based on the above embodiments, the power controller further includes a bus capacitor C1 and a pre-charge module 200; the first end of the bus capacitor C1 is connected to the first bus L1, and the second end of the bus capacitor C1 is connected to the second bus L2; ​​the first end of the pre-charge module 200 is connected to the first bus L1, and the second end of the pre-charge module 200 is connected to the first end of the bus capacitor C1.

[0071] Among them, the bus capacitor C1 is used to provide instantaneous power to the downstream circuit.

[0072] Figure 11 This is a schematic diagram of another power controller provided according to an embodiment of the present invention, with reference to... Figure 11 Based on the above embodiments, optionally, the pre-charging module 200 includes a third protection unit 201 and a current limiting unit 202; the first end of the third protection unit 201 is connected to the first bus L1, the second end of the third protection unit 201 is connected to the first end of the current limiting unit 202, and the second end of the current limiting unit 202 is connected to the first end of the bus capacitor C1; the third protection unit 201 includes a third diode D3, the first electrode of the third diode D3 is connected to the first bus L1, and the second electrode of the third diode D3 is connected to the current limiting unit 202; the current limiting unit 202 includes at least two resistors, and the at least two resistors are connected between the first electrode of the third diode D3 and the first end of the bus capacitor C1.

[0073] This embodiment exemplarily shows that the current limiting unit 202 includes five resistors, namely the ninth resistor R9, the tenth resistor R10, the eleventh resistor R11, the twelfth resistor R12, and the thirteenth resistor R13.

[0074] Specifically, the bus capacitor C1 is charged via a high-voltage battery pack. When the control module determines that the high-voltage DC bus is positively connected, it controls relay W1 to engage after a delay. During this delay, the high-voltage battery pack charges the bus capacitor C1 through the pre-charging module 200. The control module also monitors the voltage across the bus capacitor C1. When the voltage across the bus capacitor C1 reaches a preset voltage, it controls relay W1 to engage, thus preventing a large instantaneous current from flowing through the bus capacitor C1 during pre-charging. For example, when the bus voltage is 500V, the preset voltage can be 450V. When the voltage across the bus capacitor C1 reaches 450V, relay W1 is closed. At this time, the voltage before relay W1 closes rises slowly, and the difference between the voltage after relay W1 closes and the initial voltage is much smaller.

[0075] It should be understood that the various forms of processes shown above can be used, with steps rearranged, added, or deleted. For example, the steps described in this utility model can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this utility model can be achieved, and this is not limited herein.

[0076] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A high-voltage DC bus protection circuit, characterized in that, include: The system comprises a voltage divider module, a first protection module, a second protection module, and a switch module; the DC bus includes a first bus and a second bus. The first protection module is connected in series with the first busbar. The first end of the voltage divider module is connected to the first busbar, and the second end of the voltage divider module is connected to the control terminal of the switch module. The first end of the switch module is connected to the power supply voltage, and the second end of the switch module outputs a first detection signal. The third end of the voltage divider module is connected to the first end of the second protection module, and the second end of the second protection module is connected to the third end of the switch module. The third end and the fourth end of the second protection module are both connected to the second busbar. The first protection module is used to operate according to the first detection signal.

2. The high-voltage DC bus protection circuit according to claim 1, characterized in that, It also includes a control module; the first protection module includes a relay; The control module is connected to the second terminal of the switch module and the relay respectively, and the control module is used to control the operation of the relay according to the first detection signal.

3. The high-voltage DC bus protection circuit according to claim 1, characterized in that, The second protection module includes a first protection unit and a second protection unit; The first end of the first protection unit is connected to the third end of the voltage divider module, and the second end of the first protection unit is connected to the second busbar; the first end of the second protection unit is connected to the third end of the switch module, and the second end of the second protection unit is connected to the second busbar.

4. The high-voltage DC bus protection circuit according to claim 3, characterized in that, The first protection unit includes a first diode, and the second protection unit includes a second diode; The first terminal of the first diode is connected to the third terminal of the voltage divider module, and the second terminal of the first diode is connected to the second busbar; the first terminal of the second diode is connected to the third terminal of the switch module, and the second terminal of the second diode is connected to the second busbar. The voltage ratings of the first diode and the second diode are greater than the voltage of the DC bus.

5. The high-voltage DC bus protection circuit according to claim 1, characterized in that, The voltage divider module includes at least two resistors, which are connected in series between the first busbar and the first terminal of the first protection module.

6. The high-voltage DC bus protection circuit according to claim 1, characterized in that, The switching module includes a first switching unit, a driving unit, a pull-up unit, and a pull-down unit; The first end of the drive unit is connected to the third end of the voltage divider module, the second end of the drive unit is connected to the control end of the first switch unit, the first end of the first switch unit is connected to the first end of the pull-up unit, the second end of the pull-up unit is connected to the power supply voltage, the second end of the first switch unit is connected to the first end of the pull-down unit, and the second end of the pull-down unit is connected to the control end of the first switch unit.

7. The high-voltage DC bus protection circuit according to claim 6, characterized in that, The first switching unit includes a first transistor, the driving unit includes a first resistor, the pull-up unit includes a second resistor, and the pull-down unit includes a third resistor; The first end of the first resistor is connected to the third end of the voltage divider module, the second end of the first resistor is connected to the control electrode of the first transistor, the first electrode of the first transistor is connected to the first end of the second resistor, the second end of the second resistor is connected to the power supply voltage, the second electrode of the first transistor is connected to the first end of the third resistor, and the second end of the third resistor is connected to the control electrode of the first transistor.

8. The high-voltage DC bus protection circuit according to claim 1, characterized in that, It also includes a digital isolation module; The first end of the digital isolation module is connected to the second end of the switch module, and the digital isolation module is used to output a second detection signal based on the first detection signal.

9. A power controller, characterized in that, Includes the DC bus protection circuit as described in any one of claims 1-8; the power controller further includes a bus capacitor and a pre-charge module; The first end of the bus capacitor is connected to the first bus, and the second end of the bus capacitor is connected to the second bus; the first end of the pre-charge module is connected to the first bus, and the second end of the pre-charge module is connected to the first end of the bus capacitor.

10. The power controller according to claim 9, characterized in that, The pre-charging module includes a third protection unit and a current limiting unit; The first end of the third protection unit is connected to the first busbar, the second end of the third protection unit is connected to the first end of the current limiting unit, and the second end of the current limiting unit is connected to the first end of the busbar capacitor. The third protection unit includes a third diode, the first terminal of which is connected to the first busbar, and the second terminal of which is connected to the current limiting unit. The current limiting unit includes at least two resistors, which are connected between the first terminal of the third diode and the first terminal of the bus capacitor.

Images