Discharging device and inverter

Abstract

The present disclosure relates to a discharge device and an inverter, the discharge device comprising: a first switching circuit which is turned on when a first discharge control signal is received, and which is turned off when the first discharge control signal is not received, and which is turned off when the first discharge control signal is not received; wherein the first discharge control signal is a discharge control signal generated when an emergency stop event occurs; and a first discharge circuit including a discharge conductor having an equivalent resistance less than a resistance threshold or falling within a resistance threshold range, and a tolerable temperature higher than a tolerable temperature threshold or falling within a tolerable temperature threshold range, and the electric energy in the direct current link capacitor of the new energy automobile is released through the discharge conductor. Therefore, the release of the electric energy in the direct current link capacitor of the new energy automobile can be completed within the millisecond-level discharge time under the condition that an emergency stop event such as a collision event occurs.

Description

Technical Field

[0001] The present disclosure relates to the field of vehicle technology, and in particular to a discharge device and an inverter. Background Art

[0002] New energy vehicles can be powered by high-voltage batteries, using inverters to drive motors to provide power to the entire vehicle, and include other high-voltage power supply equipment. In order to output a stable voltage, the high-voltage circuit includes a high-voltage energy storage unit such as a DC link capacitor.

[0003] Usually, when the high voltage connection is disconnected due to an accident (such as a collision), in order to ensure the safety of personnel, the voltage (high voltage) in the high voltage energy storage unit must be quickly discharged to below 60 volts (V) in a very short time to prevent personnel from being hit by the high voltage.

[0004] However, the scheme for releasing the voltage in the high-voltage energy storage unit in the prior art (referred to as "discharge scheme") may only be able to complete the release of the voltage in the high-voltage energy storage unit within a short time, such as 2 seconds (s) (referred to as "fast discharge"), but cannot complete the release of the voltage in the high-voltage energy storage unit within an extremely short time, such as a discharge time of milliseconds.

[0005] Therefore, the discharge time of the discharge scheme in the prior art is usually within 2 seconds (s), which is relatively long and cannot meet the discharge requirements of the millisecond (ms) level. For some scenarios that need to meet the discharge requirements of the millisecond level, such as collision events, since the discharge time of the discharge scheme in the prior art is relatively long, it may cause high-voltage electric shock to the driver or people outside the vehicle, resulting in personal injury, so the high-voltage safety of the vehicle under the collision event needs to be improved. In addition, the discharge scheme in the prior art may only be integrated into the inverter and cannot be standardized. Summary of the invention

[0006] In view of this, the present disclosure proposes a discharge device and an inverter, so that in the event of an emergency stop event such as a collision, the electrical energy in the DC link capacitor of a new energy vehicle can be released within a discharge time of milliseconds (referred to as "extremely fast discharge").

[0007] According to one aspect of the present disclosure, a discharge device is provided, comprising: a first switch circuit, wherein the first switch circuit is turned on when a first discharge control signal is received, and the first switch circuit is turned off when the first discharge control signal is not received, wherein the first discharge control signal is a discharge control signal generated when an emergency stop event occurs; and a first discharge circuit, comprising a discharge conductor having an equivalent resistance less than a resistance threshold or falling within a resistance threshold range and a tolerance temperature higher than a tolerance temperature threshold or falling within a tolerance temperature threshold range, wherein when the first switch circuit is turned on, the electric energy in the DC link capacitor of the new energy vehicle is released via the discharge conductor.

[0008] In a possible implementation manner, the discharge conductor includes a copper wire or an aluminum wire.

[0009] In a possible implementation manner, the first switch circuit includes a switch tube.

[0010] In a possible implementation, the switch tube includes an IGBT or a MOSFET.

[0011] According to another aspect of the present disclosure, an inverter is provided, comprising: the above-mentioned discharge device; a second switching circuit, wherein the second switching circuit is turned on when a second discharge control signal is received, and the second switching circuit is turned off when the second discharge control signal is not received, wherein the second discharge control signal is a discharge control signal generated when the electric energy in the DC link capacitor needs to be released in the event of a non-emergency stop event; and a second discharge circuit, which comprises a discharge resistor and an overheat detection circuit, wherein when the second switching circuit is turned on, the electric energy in the DC link capacitor is released via the discharge resistor, wherein during the period of releasing the electric energy in the DC link capacitor via the discharge resistor, if the overheat detection circuit detects that the temperature of the discharge resistor exceeds a temperature threshold, the release of the electric energy in the DC link capacitor via the discharge resistor is terminated regardless of whether the release of the electric energy in the DC link capacitor is completed.

[0012] In a possible implementation, the inverter further includes: a discharge control circuit, which is used to turn on the first switching circuit when a first active discharge request corresponding to the emergency stop event is received from the high-voltage inverter control module of the new energy vehicle and a dissipation signal indicating that the electric energy of the high-voltage DC bus of the new energy vehicle needs to be dissipated is obtained, wherein the electric energy of the high-voltage DC bus corresponds to the electric energy in the DC link capacitor.

[0013] In a possible implementation, the inverter further includes: a voltage change rate detection module, used to detect the voltage change rate of the high-voltage DC bus, wherein, when the voltage change rate exceeds a discharge threshold, the discharge control circuit obtains the dissipation signal, wherein the dissipation signal includes the voltage change rate exceeding the discharge threshold.

[0014] In a possible implementation, the inverter further includes: a high- and low-voltage electrical isolation circuit for electrically isolating the high-voltage part from the low-voltage part in the inverter, wherein the first active discharge request is transmitted from the high-voltage inverter control module to the discharge control circuit via the high- and low-voltage electrical isolation circuit.

[0015] In one possible implementation, when receiving a second active discharge request corresponding to the non-emergency stop event from the high-voltage inverter control module and obtaining a dissipation signal indicating that the electric energy of the high-voltage DC bus of the new energy vehicle needs to be dissipated, the discharge control circuit turns on the second switching circuit.

[0016] In one possible implementation, when a second active discharge request corresponding to the non-emergency stop event is received from the high-voltage inverter control module, a dissipation signal indicating that the electric energy of the high-voltage DC bus needs to be dissipated is obtained, and it is detected that the low-voltage ignition power supply of the new energy vehicle is in a disconnected state, the discharge control circuit turns on the second switching circuit.

[0017] According to the discharge device and inverter disclosed in the present invention, when receiving the first discharge control signal generated when an emergency stop event occurs, the first switch circuit of the discharge device is turned on, and the electric energy in the DC link capacitor of the new energy vehicle is released through the discharge conductor with small resistance and high temperature resistance (whose equivalent resistance is less than the resistance threshold or falls within the resistance threshold range, and the tolerable temperature is higher than the tolerable temperature threshold or falls within the tolerable temperature threshold range) included in the first discharge circuit of the discharge device, thereby achieving extremely fast discharge.

[0018] Since the present invention can achieve extremely fast discharge, it can effectively reduce the risk of high-voltage electric shock to the driver and passengers or people outside the vehicle in the event of an emergency stop, thereby effectively improving the high-voltage safety of the vehicle in the event of an emergency stop.

[0019] In addition, since the discharge device of the present invention can achieve extremely fast discharge through a simple circuit structure including a first switching circuit and a first discharge circuit, the discharge device of the present invention can be standardized and plug-and-play, and can be integrated into a vehicle inverter of a new energy vehicle or used as an independent module in conjunction with a vehicle inverter for discharge.

[0020] For example, if the discharge device is used as an independent module, the discharge device can be connected to the high-voltage DC bus of a new energy vehicle, and discharge can be achieved together with the discharge device connected to the high-voltage DC bus and the vehicle inverter, wherein extremely fast discharge is achieved through the discharge device and fast discharge is achieved through the inverter.

[0021] For another example, the discharge device can be integrated into a vehicle inverter. Thus, the vehicle inverter integrated with the discharge device can achieve both extremely fast discharge and rapid discharge. As for which type of discharge is achieved, it can be determined based on whether an emergency stop event occurs.

[0022] In addition, since the specification of the discharge conductor of the discharge device of the present invention is adjustable, the discharge time of the extremely rapid discharge is also adjustable, so the discharge device of the present invention has good versatility.

[0023] Further features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.

[0025] Figure 1 is a schematic diagram of an inverter according to the present exemplary embodiment.

[0026] Figure 2 is a schematic diagram of a discharge device according to this exemplary embodiment.

[0027] Figure 3 is a schematic diagram of a discharge device according to this exemplary embodiment.

[0028] Figure 4 is a schematic diagram of an inverter according to the present exemplary embodiment.

[0029] Figure 5 is a schematic diagram of an inverter according to the present exemplary embodiment. DETAILED DESCRIPTION

[0030] Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0031] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0032] In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present disclosure can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present disclosure.

[0033] See also Figure 1 The inverter 10 includes a DC capacitor 103, a voltage change rate detection module 104, an electrical isolation circuit 105, a discharge control circuit 106, a switch tube 107, a discharge resistor 108, an overheat detection circuit 109, a transformer control chip 110, a switch tube 111, and a high-voltage switching power supply 112. The voltage change rate detection module 104, the electrical isolation circuit 105, the discharge control circuit 106, the switch tube 107, the discharge resistor 108, and the overheat detection circuit 109 constitute a discharge circuit 100 of the inverter 10.

[0034] During normal power-on, the high-voltage main relay 101 is engaged, the high-voltage battery 102 supplies power to the new energy vehicle, and a stable voltage is output via the DC capacitor 103. The high-voltage switching power supply 112 includes a primary winding and a power device drive power supply 1 to 3. The switch tube 111 is controlled by the transformer control chip 110 to further control the high-voltage switching power supply 112 to drive the motor of the new energy vehicle and provide power for the entire vehicle, so that the new energy vehicle works normally.

[0035] During normal operation of the new energy vehicle, there is no need to release the electrical energy in the DC capacitor 103, so the discharge control circuit 106 will not receive the discharge instruction output via the electrical isolation circuit 105, and the discharge control circuit 106 outputs a shutdown signal for disconnecting the switch tube 107, so the switch tube 107 is disconnected, and the electrical energy in the DC capacitor 103 is not consumed via the discharge resistor 108.

[0036] In contrast, when the power is cut off, such as when a non-emergency stop event occurs and the vehicle needs to be parked, the high-voltage main relay 101 is disconnected, and the electrical energy in the DC capacitor 103 needs to be released through the discharge circuit 100 within a short time, such as 2 seconds. Therefore, the discharge control circuit 106 receives the discharge instruction output via the electrical isolation circuit 105 and outputs a conduction signal for turning on the switch tube 107 according to the acquired voltage change rate. Therefore, the switch tube 107 is turned on, and the electrical energy in the DC capacitor 103 is consumed via the discharge resistor 108.

[0037] During the period of releasing the electric energy in the DC capacitor 103 (also referred to as during the discharge process), the temperature of the discharge resistor 108 is detected via the overheat detection circuit 109. When the temperature of the discharge resistor 108 exceeds the temperature threshold, the overheat detection circuit 109 sends an alarm signal indicating that the temperature of the discharge resistor 108 is too high to the discharge control circuit 106. When the discharge control circuit 106 receives the alarm signal, it outputs a shutdown signal for disconnecting the switch tube 107 to stop releasing the electric energy in the DC capacitor 103.

[0038] However, as described in the background technology, although the above-mentioned discharge circuit 100 can release the voltage in the DC capacitor 103 in a relatively short time, such as 2s, the discharge time of the discharge circuit 100 is relatively long and cannot meet the discharge requirement of the discharge time of milliseconds. For some scenarios that need to meet the discharge requirement of the discharge time of milliseconds, such as a collision event, due to the long discharge time, it may cause high-voltage electric shock to the driver or the outsiders, thereby causing personal injury, so the high-voltage safety of the vehicle under the collision event needs to be improved. In addition, the discharge circuit 100 may only be integrated into the inverter 10 and cannot be used as an independent module, so it cannot be standardized and plug-and-play.

[0039] To this end, the present disclosure recognizes that the reason why the discharge circuit 100 is difficult to achieve extremely fast discharge may be that the electric energy in the DC capacitor 103 is high-voltage electric energy and the discharge resistor 108 is difficult to withstand a temperature higher than the tolerance temperature threshold. If a discharge conductor with a resistance lower than the resistance threshold and a tolerance temperature higher than the tolerance temperature threshold is used for discharge, then, since the resistance of the discharge conductor is lower than the resistance threshold, the discharge conductor can be equivalent to a small resistor, which can meet the discharge time of milliseconds to complete the release of the electric energy in the DC capacitor 103. Since the tolerance temperature of the discharge conductor is higher than the tolerance temperature threshold, during the period of releasing the electric energy in the DC capacitor 103, the discharge conductor will not be damaged due to inability to withstand high temperature, thereby achieving extremely fast discharge.

[0040] Therefore, according to the present disclosure, a discharge device is proposed. When receiving a first discharge control signal generated when an emergency stop event occurs, the first switch circuit of the discharge device is turned on, and the electric energy in the DC link capacitor of the new energy vehicle is released through the discharge conductor with low resistance and high temperature resistance included in the first discharge circuit of the discharge device. In this way, extremely fast discharge can be achieved, thereby solving the above-mentioned technical problems to be solved by the present disclosure.

[0041] Based on the above ideas, Figure 2-3 The discharge device shown can be applied to the inverter in new energy vehicles.

[0042] See also Figure 2The discharge device 200 of this exemplary embodiment may include a first switch circuit 210 and a first discharge circuit 220, the first discharge circuit 220 includes a discharge conductor 221, the equivalent resistance of the discharge conductor 221 is less than the resistance threshold or falls within the resistance threshold range, and the tolerance temperature is higher than the tolerance temperature threshold or falls within the tolerance temperature threshold range.

[0043] When the first discharge control signal 11 is received, the first switch circuit 210 is turned on, and the electric energy in the DC link capacitor of the new energy vehicle is released through the discharge conductor 221. In contrast, when the first discharge control signal 11 is not received, the first switch circuit 210 is turned off, and the discharge device 200 does not work, that is, the electric energy in the DC link capacitor of the new energy vehicle is not released through the discharge conductor 221.

[0044] In this embodiment, the discharge conductor 221 may be equivalent to a resistor, and the resistance value of the equivalent resistor may be less than the resistance threshold or fall within the resistance threshold range. In a possible implementation, the resistance threshold is, for example, 1.1 ohms (Ω), that is, the resistance value of the equivalent resistor of the discharge conductor 221 may be less than 1.1Ω. In a possible implementation, the resistance threshold is, for example, 0.8Ω, that is, the resistance value of the equivalent resistor of the discharge conductor 221 may be less than 0.8Ω. In a possible implementation, the resistance threshold range is, for example, [0.2Ω, 1Ω], that is, the resistance value of the equivalent resistor of the discharge conductor 221 may be greater than or equal to 0.2Ω and less than or equal to 1Ω. In a possible implementation, the resistance threshold range is, for example, [0.5Ω, 1Ω], that is, the resistance value of the equivalent resistor of the discharge conductor 221 may be greater than or equal to 0.5Ω and less than or equal to 1Ω.

[0045] In a possible implementation, the resistance value of the equivalent resistor may be determined according to the discharge time of the extremely rapid discharge, thereby determining the specification of the discharge conductor 221 (ie, determining the length, width, and thickness of the discharge conductor 221 ).

[0046] For example, if the discharge time of the extreme discharge is 50ms, the voltage on the high-voltage DC bus is 900 volts (V), and the capacitance of the DC link capacitor is 600 microfarads (uF), that is, the 600uF DC link capacitor needs to be discharged from the high-voltage DC bus voltage of 900V to 60V within 50ms. Assuming that a copper sheet is used as the discharge conductor 221, it is necessary to select a copper sheet with a certain length, width and thickness so as to have an equivalent resistance of 0.033Ω.

[0047] In one possible implementation, the formula To calculate the equivalent resistance of the discharge conductor 221, where R represents the resistance of the equivalent resistance of the discharge conductor 221, C represents the capacitance of the DC link capacitor, and t dis Indicates the discharge time of extremely fast discharge, V dis Indicates the voltage value after extremely fast discharge, V DCmax Represents the high-voltage DC bus voltage. Once the equivalent resistance of the discharge conductor 221 is determined, the specification of the discharge conductor 221 can be determined according to the resistivity of the discharge conductor 221 and the resistance value of the equivalent resistance.

[0048] In this embodiment, considering that the discharge conductor 221 generates high heat during the extremely rapid discharge, the high heat will cause the temperature of the discharge conductor 221 to rise extremely rapidly. If the discharge conductor 221 cannot withstand high temperatures such as 120°C or 130°C, the discharge conductor 221 will be damaged by the high heat generated during the extremely rapid discharge. Therefore, in addition to meeting the resistance requirement that the equivalent resistance is less than the resistance threshold or falls within the resistance threshold range, the discharge conductor 221 also needs to be able to withstand high temperatures, that is, the withstand temperature of the discharge conductor 221 needs to be higher than the withstand temperature threshold, such as 120°C or 130°C, or the withstand temperature of the discharge conductor 221 needs to fall within the withstand temperature threshold range, such as [100°C, 130°C] or [115°C, 145°C].

[0049] Therefore, it is necessary to comprehensively consider the requirements of the resistance value of the equivalent resistor and the temperature requirement of the withstand temperature to select a discharge conductor 221 that meets the resistance value requirement and the temperature requirement. For example, a copper wire or an aluminum wire can be selected as the discharge conductor 221. Of course, any other suitable conductor that meets the resistance value requirement and the temperature requirement can also be selected as the discharge conductor 221. Due to space limitations, this disclosure will not further describe this.

[0050] In this embodiment, an emergency stop event refers to an event that requires an emergency stop for a moving vehicle. In a possible implementation, the emergency stop event may include but is not limited to a collision event. A non-emergency stop event refers to an event that does not require an emergency stop for a moving vehicle but still requires the release of electrical energy in a DC link capacitor. In a possible implementation, the non-emergency stop event may include but is not limited to an event that requires disconnection of a high-voltage connection due to a fault, an event that requires disconnection of a high-voltage connection due to normal power-off, etc.

[0051] During the driving process of the new energy vehicle, the corresponding modules of the new energy vehicle, such as the collision detection module, can detect in real time whether the vehicle has a collision event. Once the collision detection module detects that the vehicle has a collision event, the collision detection module sends a collision signal corresponding to the collision event to the high-voltage inverter control module. The high-voltage inverter control module generates an active discharge request signal based on the collision signal, and transmits the active discharge request signal to the discharge control circuit via the high and low voltage electrical isolation circuit. The discharge control circuit generates a first discharge control signal 11 for triggering an extremely fast discharge based on the active discharge request signal to control the first switch circuit 210 to be turned on, thereby releasing the electrical energy in the DC link capacitor via the discharge conductor 221.

[0052] In a possible implementation, the extremely fast discharge process is completed after the voltage in the DC link capacitor 103 on the high-voltage power bus is released to a voltage threshold, such as 60 V. The high-voltage inverter control module may turn off the active discharge request and prepare to enter a dormant state.

[0053] Accordingly, when the collision detection module does not detect a collision event of the vehicle, the collision detection module will not send a collision signal to the high-voltage inverter control module. The high-voltage inverter control module will not generate an active discharge request signal based on the collision signal, and naturally will not transmit the active discharge request signal to the discharge control circuit via the high- and low-voltage electrical isolation circuit. The discharge control circuit will not generate a first discharge control signal 11 for triggering extremely fast discharge based on the active discharge request signal, thereby controlling the first switch circuit 210 to be disconnected, so that the electrical energy in the DC link capacitor will not be released via the discharge conductor 221.

[0054] It should be noted that the collision detection module can use any suitable method in the prior art to detect whether a vehicle collision event occurs. Due to space limitations, the present disclosure will not further describe the specific detection method for whether a vehicle collision event occurs.

[0055] According to the discharge device disclosed in the present invention, when receiving the first discharge control signal generated when an emergency stop event occurs, the first switch circuit is turned on, and the voltage (for example, 900V) in the DC link capacitor of the new energy vehicle is released to an allowable voltage (for example, 60V) via a discharge conductor with a small resistance and high temperature resistance (whose equivalent resistance is less than the resistance threshold or falls within the resistance threshold range, and the tolerable temperature is higher than the tolerable temperature threshold or falls within the tolerable temperature threshold range) included in the first discharge circuit, thereby achieving extremely fast discharge.

[0056] Since the present invention can achieve extremely fast discharge, even in the event of an emergency stop, it can avoid the possibility that the high-voltage conductor of the high-voltage component will contact the vehicle body due to the emergency stop, thereby causing the driver and passengers or people outside the vehicle to receive high-voltage electric shocks. This can effectively reduce the risk of the driver and passengers or people outside the vehicle receiving high-voltage electric shocks in the event of an emergency stop, thereby effectively improving the high-voltage safety of the vehicle in the event of an emergency stop.

[0057] In addition, since the discharge device of the present invention can achieve extremely fast discharge through a simple circuit structure including a first switching circuit and a first discharge circuit, the discharge device of the present invention can be standardized and plug-and-play, and can be integrated into a vehicle inverter of a new energy vehicle or used as an independent module in conjunction with a vehicle inverter for discharge.

[0058] For example, if the discharge device is used as an independent module, the discharge device can be connected to the high-voltage DC bus of a new energy vehicle, and discharge can be achieved together with the discharge device connected to the high-voltage DC bus and the vehicle inverter, wherein extremely fast discharge is achieved through the discharge device and fast discharge is achieved through the inverter.

[0059] For another example, the discharge device can be integrated into a vehicle inverter. Thus, the vehicle inverter integrated with the discharge device can achieve both extremely fast discharge and rapid discharge. As for which type of discharge is achieved, it can be determined based on whether an emergency stop event occurs.

[0060] In addition, since the specification of the discharge conductor of the discharge device of the present invention is adjustable, the discharge time of the extremely rapid discharge is also adjustable, so the discharge device of the present invention has good versatility.

[0061] In one possible implementation, see Figure 3 The discharge conductor 221 includes a copper wire or an aluminum wire 2211, and the first switch circuit 210 includes a switch tube 211. The discharge device 300 of this embodiment may include a switch tube 211 and a copper wire or an aluminum wire 2211.

[0062] After selecting the discharge conductor 221 that meets the resistance and temperature requirements, the selected discharge conductor 221 can be laid flat on a high temperature resistant PCB board along the axis of a circle, that is, the selected discharge conductor 221 is laid out in a plane on the PCB board, so that the discharge conductor 221 laid flat on the PCB board can be equivalent to a small resistor and can withstand high temperature. The selection of the specifications of the copper wire or aluminum wire 2211 can refer to the description of the discharge conductor 221 above, and will not be repeated here.

[0063] In this embodiment, if the control end of the switch tube 211 receives the first discharge control signal 11, the switch tube 211 is turned on, and the copper wire or aluminum wire 2211 is connected to the high-voltage DC bus. The voltage in the high-voltage DC bus (for example, 900V) is released to an allowable voltage (for example, 60V) via the copper wire or aluminum wire 2211, thereby achieving extremely fast discharge.

[0064] Relatively speaking, if the control end of the switch tube 211 does not receive the first discharge control signal 11, the switch tube 211 is disconnected, the copper wire or aluminum wire 2211 is not connected to the high-voltage DC bus, and the voltage in the high-voltage DC bus will not be released through the copper wire or aluminum wire 2211, that is, no extreme discharge is performed.

[0065] That is to say, whether the copper wire or aluminum wire 2211 is discharged depends on whether the switch tube 211 is turned on.

[0066] In a possible implementation, the switch tube 211 includes an IGBT or a MOSFET.

[0067] In this embodiment, in order to achieve extremely fast discharge, a switch tube 211 with a fast conduction speed needs to be used, for example, an IGBT or a MOSFET can be used as the switch tube 211. Of course, it should be understood that other electronic switch tubes with a fast conduction speed can also be selected as the switch tube 211, and due to space limitations, this disclosure will not be described in detail.

[0068] See also Figure 4 The inverter 400 may include a second switch circuit 410, a second discharge circuit 420 and a discharge device 430. The discharge device 430 may be Figure 2 The discharge device 200 or Figure 3 The discharge device 300 in FIG.

[0069] When the second discharge control signal 12 is received, the second switch circuit 410 turns on the second switch circuit 420 to release the electric energy in the DC link capacitor via the discharge resistor 421. When the second discharge control signal 12 is not received, the second switch circuit 410 turns off the second switch circuit 420 to not release the electric energy in the DC link capacitor via the discharge resistor 421. The second discharge control signal 12 is a discharge control signal generated when the electric energy in the DC link capacitor needs to be released in the event of a non-emergency stop event.

[0070] During the period of releasing the electric energy in the DC link capacitor via the discharge resistor 421, if the overheat detection circuit 422 detects that the temperature of the discharge resistor 421 exceeds the temperature threshold, the release of the electric energy in the DC link capacitor via the discharge resistor 421 is terminated regardless of whether the release of the electric energy in the DC link capacitor is completed.

[0071] In this embodiment, when the first discharge control signal 11 is received, the discharge device 430 is connected to the high-voltage DC bus, and the voltage of the high-voltage DC bus (for example, 900V) is released to an allowable voltage (for example, 60V) via the discharge device 430; when the second discharge control signal 12 is received, the second switch circuit 410 is turned on, and the second discharge circuit 420 is connected to the high-voltage DC bus, and the voltage of the high-voltage DC bus (for example, 900V) is released to an allowable voltage (for example, 60V) via the discharge resistor 421.

[0072] Therefore, the inverter 400 can control whether to implement extremely fast discharge via the discharge device 430 or to implement rapid discharge via the second switch circuit 410 and the second discharge circuit 420 according to whether the first discharge control signal 11 or the second discharge control signal 12 is received.

[0073] In one possible implementation, see Figure 5 The inverter 500 may further include a discharge control circuit 106, which is used to turn on the first switch circuit 210 (switch tube 211) when receiving a first active discharge request corresponding to an emergency stop event from a high-voltage inverter control module of the new energy vehicle and obtaining a dissipation signal indicating that the electric energy of the high-voltage DC bus of the new energy vehicle needs to be dissipated, wherein the electric energy of the high-voltage DC bus corresponds to the electric energy in the DC link capacitor 103.

[0074] In one possible implementation, upon receiving a second active discharge request corresponding to a non-emergency stop event from the high-voltage inverter control module and obtaining a dissipation signal indicating the need to dissipate the electrical energy of the high-voltage DC bus of the new energy vehicle, the discharge control circuit 106 turns on the second switching circuit 420 (switch tube 107).

[0075] In one possible implementation, when a second active discharge request corresponding to a non-emergency stop event is received from a high-voltage inverter control module, a dissipation signal indicating that the electric energy of the high-voltage DC bus needs to be dissipated is obtained, and when it is detected that the low-voltage ignition power supply of the new energy vehicle is in a disconnected state, the discharge control circuit 106 turns on the second switch circuit 420 (switch tube 107).

[0076] In one possible implementation, see Figure 5 The inverter 500 may further include a voltage change rate detection module 104, which is used to detect the voltage change rate of the high-voltage DC bus, wherein when the voltage change rate exceeds a discharge threshold, the discharge control circuit 104 obtains a dissipation signal, wherein the dissipation signal includes a voltage change rate exceeding the discharge threshold.

[0077] In one possible implementation, see Figure 5 The inverter 500 may further include a high- and low-voltage electrical isolation circuit 105, which is used to electrically isolate the high-voltage part from the low-voltage part in the inverter, wherein the first active discharge request is transmitted from the high-voltage inverter control module to the discharge control circuit 106 via the high- and low-voltage electrical isolation circuit 105.

[0078] The discharging process involved in the inverter 500 includes:

[0079] When the driver stops the vehicle and turns off the low-voltage ignition power supply of the new energy vehicle, the high-voltage battery management module disconnects the high-voltage main relay 101. The high-voltage battery management module or the vehicle controller VCU sends the shutdown status information indicating that the high-voltage main relay 101 is disconnected to the CAN network, and the VCU sends an active discharge request to the high-voltage inverter control module.

[0080] If the high-voltage inverter control module receives the shutdown status information, the active discharge request from the VCU, and detects that the low-voltage ignition power supply of the new energy vehicle is in the disconnected state, the voltage of the high-voltage DC power bus is greater than the discharge threshold (for example, 60V), and there is no fault related to the active discharge device, etc., the high-voltage inverter control module sends an active discharge request electrical signal (corresponding to the second discharge control signal 12, also called a discharge instruction).

[0081] The discharge instruction sent by the high-voltage inverter control module is transmitted to the discharge control circuit 106 through the electrical isolation circuit 105, and the discharge control circuit 106 turns on the switch tube 107.

[0082] Thus, the electric energy in the DC link capacitor 103 is quickly released via the discharge resistor 108. Therefore, according to the inverter 500 of the present disclosure, the electric energy in the DC link capacitor 103 can be consumed in the form of heat after a discharge time of no more than 2 seconds.

[0083] If during the discharge process, the temperature of the discharge resistor 108 is too high due to heat (detected by the overheat detection circuit 109, which is a thermistor arranged near the discharge resistor 108) or the voltage change rate across the DC link on the high-voltage DC power bus does not reach a preset threshold, the rapid discharge process will be terminated.

[0084] After the voltage in the DC link capacitor 103 is less than 60 V, the rapid discharge process is completed. The high-voltage inverter control module turns off the active discharge request electrical signal corresponding to the second discharge control signal 12 and prepares to enter the dormant state.

[0085] When an emergency stop event such as a collision occurs, the high-voltage battery management module disconnects the high-voltage main relay 101, and the high-voltage battery management module or the vehicle controller VCU sends shutdown state information indicating that the high-voltage main relay 101 is disconnected to the CAN network. The collision detection module detects a collision signal and sends the collision signal to the high-voltage inverter control module.

[0086] If the high-voltage inverter control module receives the shutdown status information, the collision signal, the voltage of the high-voltage DC power bus is greater than the discharge threshold (for example, 60V), there is no fault related to the active discharge device, etc., the high-voltage inverter control module sends an active discharge request electrical signal (corresponding to the first discharge control signal 11, also called a discharge instruction).

[0087] The discharge instruction sent by the high-voltage inverter control module is transmitted to the discharge control circuit 106 through the electrical isolation circuit 105 , and the discharge control circuit 106 turns on the switch tube 211 .

[0088] Thus, the electric energy in the DC link capacitor 103 is released extremely quickly via the copper wire or the aluminum wire 2211. Therefore, according to the inverter 500 of the present disclosure, the electric energy in the DC link capacitor 103 can be consumed in the form of heat after a discharge time of milliseconds.

[0089] After the voltage in the DC link capacitor 103 is less than 60 V, the extremely fast discharge process is completed. The high-voltage inverter control module turns off the active discharge request electrical signal corresponding to the first discharge control signal 11 and prepares to enter the dormant state.

[0090] Therefore, the inverter 500 integrated with the discharge device 430 can realize both extremely fast discharge and rapid discharge. As for which type of discharge is realized, it can be determined according to whether an emergency stop event occurs.

[0091] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A discharge device, applied to an inverter of a new energy vehicle, characterized in that: include: a first switch circuit, wherein the first switch circuit is turned on when a first discharge control signal is received, and the first switch circuit is turned off when the first discharge control signal is not received, wherein the first discharge control signal is a discharge control signal generated when an emergency stop event occurs; and A first discharge circuit comprises a discharge conductor whose equivalent resistance is less than a resistance threshold or falls within a resistance threshold range and whose tolerance temperature is higher than a tolerance temperature threshold or falls within a tolerance temperature threshold range, wherein when the first switch circuit is turned on, the electric energy in the DC link capacitor of the new energy vehicle is released via the discharge conductor.

2. The discharge device according to claim 1, characterized in that: The discharge conductor includes a copper wire or an aluminum wire.

3. The discharge device according to claim 1 or 2, characterized in that: The first switch circuit includes a switch tube.

4. The discharge device according to claim 3, characterized in that: The switch tube includes an IGBT or a MOSFET.

5. An inverter, applied to new energy vehicles, characterized in that: include: The discharge device according to any one of claims 1 to 4; a second switch circuit, wherein the second switch circuit is turned on when a second discharge control signal is received, and the second switch circuit is turned off when the second discharge control signal is not received, wherein the second discharge control signal is a discharge control signal generated when the electric energy in the DC link capacitor needs to be released in the event of a non-emergency stop event; and a second discharge circuit, comprising a discharge resistor and an overheat detection circuit, wherein when the second switch circuit is turned on, the electric energy in the DC link capacitor is released via the discharge resistor, Wherein, during the period of releasing the electric energy in the DC link capacitor via the discharge resistor, if the overheat detection circuit detects that the temperature of the discharge resistor exceeds the temperature threshold, the release of the electric energy in the DC link capacitor via the discharge resistor is terminated regardless of whether the release of the electric energy in the DC link capacitor is completed.

6. The inverter according to claim 5, characterized in that: Also includes: A discharge control circuit is used to turn on the first switch circuit when a first active discharge request corresponding to the emergency stop event is received from a high-voltage inverter control module of the new energy vehicle and a dissipation signal indicating that the electric energy of the high-voltage DC bus of the new energy vehicle needs to be dissipated is obtained, wherein the electric energy of the high-voltage DC bus corresponds to the electric energy in the DC link capacitor.

7. The inverter according to claim 6, characterized in that: Also includes: A voltage change rate detection module is used to detect the voltage change rate of the high-voltage DC bus. Wherein, in the case that the voltage change rate exceeds the discharge threshold, the discharge control circuit acquires the dissipation signal, wherein the dissipation signal includes that the voltage change rate exceeds the discharge threshold.

8. The inverter according to claim 7, characterized in that: Also includes: A high-low voltage electrical isolation circuit is used to electrically isolate the high voltage part from the low voltage part in the inverter. The first active discharge request is transmitted from the high-voltage inverter control module to the discharge control circuit via the high- and low-voltage electrical isolation circuit.

9. The inverter according to any one of claims 6 to 8, characterized in that: When receiving a second active discharge request corresponding to the non-emergency stop event from the high-voltage inverter control module and obtaining a dissipation signal indicating that the electric energy of the high-voltage DC bus of the new energy vehicle needs to be dissipated, the discharge control circuit turns on the second switch circuit.

10. The inverter according to any one of claims 6 to 8, characterized in that: When receiving a second active discharge request corresponding to the non-emergency stop event from the high-voltage inverter control module, obtaining a dissipation signal indicating that the electric energy of the high-voltage DC bus needs to be dissipated, and detecting that the low-voltage ignition power supply of the new energy vehicle is in a disconnected state, the discharge control circuit turns on the second switch circuit.

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