Discharge control circuit, discharge control method and new energy vehicle

Abstract

The present invention discloses a discharge control circuit, a discharge control method and a new energy vehicle, and relates to the technical field of new energy vehicles. The discharge control circuit includes: a power battery, a DC-DC converter, a first switch, a second switch, a bus capacitor, a three-phase winding of a motor, a motor, a motor, a motor information acquisition sensor, a discharge resistor control switch, a discharge resistor, and a control device. The bus capacitor and the three-phase winding of the motor are connected in parallel with the power battery, the discharge resistor is connected in parallel between the power battery and the three-phase winding of the motor, the DC-DC converter is connected in parallel between the discharge resistor and the power battery, the discharge resistor control switch is connected in series with the discharge resistor, and the first switch, the second switch and the discharge resistor control switch are used to control whether the DC-DC converter and the discharge resistor are connected to the circuit; different discharge methods corresponding to different motor working conditions are implemented, thereby improving the rationality, stability and efficiency of the voltage rapid release scheme of the high-voltage system of the new energy vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to a discharge control circuit, a discharge control method and a new energy vehicle. Background Art

[0002] With the development and maturity of new energy vehicle technology, the market share of new energy vehicles in my country is increasing year by year, and they are widely distributed throughout the country. In order to increase charging speed and driving range, current new energy vehicles usually use high-voltage drive systems. However, due to the existence of high-voltage systems, if there is still high voltage at the high-voltage bus end in emergency situations such as vehicle collisions, it may cause harm to passengers.

[0003] The current rapid voltage release scheme for the high-voltage system of new energy vehicles is mainly to quickly disconnect the high-voltage circuit when an emergency occurs, and use the motor winding to release the residual energy in the high-voltage circuit.

[0004] However, the voltage rapid release scheme of the high-voltage system of the above-mentioned new energy vehicle does not adopt a suitable discharge method according to different working conditions, so the overall discharge scheme is not stable, reasonable and efficient enough. Summary of the invention

[0005] The main purpose of the present invention is to propose a discharge control circuit, a discharge control method and a new energy vehicle, aiming to improve the rationality, stability and efficiency of the voltage rapid release scheme of the high-voltage system of the new energy vehicle.

[0006] In a first aspect, the present invention provides a discharge control circuit, comprising: a power battery, a DC-DC converter, a first switch, a second switch, a bus capacitor, a three-phase winding of a motor, a motor, a motor information acquisition sensor, a discharge resistor control switch, a discharge resistor, and a control device; wherein the control device comprises: a discharge module, a drive module, a microcontroller module, a space vector pulse width modulation SVPWM module, an acquisition module, and a vehicle controller; two voltage monitoring points are provided in the discharge control circuit, and the two voltage monitoring points are respectively arranged at positions close to both ends of the bus capacitor;

[0007] The bus capacitor and the three-phase winding of the motor are both connected in parallel with the power battery, the discharge resistor is connected in parallel between the power battery and the three-phase winding of the motor, the DC-DC converter is connected in parallel between the discharge resistor and the power battery, the discharge resistor control switch is connected in series with the discharge resistor, the first switch is connected in series with the second switch, and the first switch is arranged between the DC-DC converter and the discharge resistor control switch, and the second switch is arranged between the discharge resistor control switch and the bus capacitor;

[0008] The motor is arranged near the three-phase winding of the motor and is electrically connected to the three-phase winding of the motor. The motor information acquisition sensor is arranged inside the motor.

[0009] The vehicle controller is communicatively connected with the discharge module and the microcontroller module; the discharge module is communicatively connected with the microcontroller module, the first switch, the second switch and the discharge resistor; the microcontroller module is communicatively connected with the three-phase winding of the motor through the SVPWM module and the drive module in turn; and the acquisition module is communicatively connected with the microcontroller module and the motor information acquisition sensor.

[0010] In an optional embodiment, the discharge control circuit further includes: two voltage sensors;

[0011] The two voltage sensors are respectively arranged at the two voltage monitoring points, and are both communicatively connected with the discharge module.

[0012] In an optional embodiment, the discharge control circuit further includes: a low-voltage battery;

[0013] The low-voltage battery is arranged at a position close to the DC-DC converter, and the DC-DC converter is electrically connected to the low-voltage battery.

[0014] In a second aspect, the present invention provides a discharge control method, which is applied to a vehicle controller in the discharge control circuit described in any one of the aforementioned embodiments, and the method comprises:

[0015] Determine and obtain the current vehicle operation status;

[0016] A quick discharge instruction is sent to the discharge module according to the current vehicle operation state, and the quick discharge instruction is used to instruct the discharge module to determine a discharge measure and perform a discharge operation.

[0017] In an optional implementation, the sending of a quick discharge instruction to a discharge module according to the current vehicle operation state includes:

[0018] If the current vehicle operation state is a first preset state, a first quick discharge instruction is sent to the discharge module, wherein the first quick discharge instruction is used to instruct to disconnect the first switch, the second switch and the discharge resistor control switch, and control the three-phase winding of the motor to operate according to a preset current, wherein the first preset state is a state in which the motor does not indicate a fault and the motor speed is less than the rated speed of the motor.

[0019] In an optional implementation, the sending of a quick discharge instruction to a discharge module according to the current vehicle operation state includes:

[0020] If the current vehicle operation state is a second preset state, a second quick discharge instruction is sent to the discharge module, and the second quick discharge instruction is used to instruct to disconnect the first switch, close the second switch and the discharge resistor control switch, control the three-phase winding of the motor to operate according to a preset current, and set the resistance value of the discharge resistor to a preset resistance value, wherein the second preset state is a state in which the motor does not indicate a fault and the motor speed is greater than the rated speed of the motor.

[0021] In an optional implementation, the sending of a quick discharge instruction to a discharge module according to the current vehicle operation state includes:

[0022] If the current vehicle operation state is the third preset state, a third quick discharge instruction is sent to the discharge module, and the third quick discharge instruction is used to instruct the closing of the first switch, the second switch and the discharge resistor control switch, and the resistance value of the discharge resistor is set to a preset resistance value, wherein the third preset state is a state in which the motor prompts a fault.

[0023] In an optional implementation manner, before controlling the three-phase winding of the motor to operate according to a preset current, the method further includes:

[0024] The preset current is calculated based on the maximum safe current of the motor, the voltage across the bus capacitor, the resistance of the three-phase winding of the motor, the rotor electrical angular velocity of the motor, the permanent magnet flux value of the motor, the winding inductance of the motor and the first preset algorithm.

[0025] In an optional implementation manner, before setting the resistance value of the discharge resistor to a preset resistance value, the method further includes:

[0026] The preset resistance value is calculated based on the motor diode voltage drop, motor rotational inertia, motor pole pair number, bus capacitance, motor electrical angular velocity at safety voltage, motor electrical angular velocity at initial voltage, motor initial voltage, motor safety voltage and a second preset algorithm.

[0027] In a third aspect, the present invention provides a new energy vehicle, comprising the discharge control circuit described in any one of the aforementioned embodiments.

[0028] The beneficial effects of the present invention are:

[0029] The discharge control circuit provided in the embodiment of the present invention includes: a power battery, a DC-DC converter, a first switch, a second switch, a bus capacitor, a three-phase winding of a motor, a motor, a motor, a motor information acquisition sensor, a discharge resistor control switch, a discharge resistor, and a control device. The bus capacitor and the three-phase winding of the motor are both connected in parallel with the power battery, the discharge resistor is connected in parallel between the power battery and the three-phase winding of the motor, the DC-DC converter is connected in parallel between the discharge resistor and the power battery, the discharge resistor control switch is connected in series with the discharge resistor, and the first switch, the second switch and the discharge resistor control switch are used to control whether the DC-DC converter and the discharge resistor are connected to the circuit; different discharge methods corresponding to different motor working conditions are implemented, thereby improving the rationality, stability and efficiency of the voltage rapid release scheme of the high-voltage system of new energy vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0031] Figure 1 A schematic diagram of a discharge control circuit structure provided in an embodiment of the present application;

[0032] Figure 2 A schematic diagram of a discharge control method flow chart provided in an embodiment of the present application;

[0033] Figure 3 A schematic diagram of the structure of a discharge control device provided in an embodiment of the present application;

[0034] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0035] Reference numerals:

[0036] P-power battery; DCDC-DC-DC converter; K1-first switch; K2-second switch; S-bleeder resistor control switch; R-bleeder resistor; C-bus capacitor; UVW-motor three-phase winding; PMSM-motor. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0039] It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures. The terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the statement "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device that includes the element.

[0040] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0041] The current rapid voltage release scheme (also called discharge scheme) of the high-voltage system of new energy vehicles is usually mainly to quickly disconnect the high-voltage circuit when an emergency occurs, and use the motor winding to release the residual energy in the high-voltage circuit. Some discharge schemes also add discharge resistors and other components to the circuit to achieve discharge. However, the above-mentioned rapid voltage release schemes of the high-voltage system of new energy vehicles have not adopted appropriate discharge methods according to different working conditions, resulting in the implemented discharge scheme not being well adapted to the motor working conditions, and the overall discharge scheme is not stable, reasonable and efficient enough. The main purpose of this application is to propose a discharge control circuit, a discharge control method and a new energy vehicle, aiming to improve the rationality, stability and efficiency of the rapid voltage release scheme of the high-voltage system of new energy vehicles.

[0042] Figure 1 A schematic diagram of a discharge control circuit structure provided in an embodiment of the present application is shown in FIG. Figure 1As shown, the circuit includes: a power battery P, a DC-DC converter DCDC, a first switch K1, a second switch K2, a bus capacitor C, a motor three-phase winding UVW, a motor PMSM, a motor information acquisition sensor, a discharge resistor control switch S, a discharge resistor R, and a control device; wherein the control device includes: a discharge module, a drive module, a microcontroller module, an SVPWM module, an acquisition module, and a vehicle controller; two voltage monitoring points are provided in the discharge control circuit, and the two voltage monitoring points are respectively arranged at positions close to both ends of the bus capacitor C.

[0043] The bus capacitor C and the three-phase winding UVW of the motor are both connected in parallel with the power battery P, the discharge resistor R is connected in parallel between the power battery P and the three-phase winding UVW of the motor, the DC-DC converter DCDC is connected in parallel between the discharge resistor R and the power battery P, the discharge resistor control switch S is connected in series with the discharge resistor R, the first switch K1 is connected in series with the second switch K2, and the first switch K1 is arranged between the DC-DC converter DCDC and the discharge resistor control switch S, and the second switch K2 is arranged between the discharge resistor control switch S and the bus capacitor C.

[0044] The motor PMSM is arranged near the motor three-phase winding UVW and is electrically connected to the motor three-phase winding UVW. The motor information acquisition sensor is arranged inside the motor PMSM.

[0045] The vehicle controller is communicatively connected with the discharge module and the microcontroller module. The discharge module is communicatively connected with the microcontroller module, the first switch K1, the second switch K2 and the discharge resistor R. The microcontroller module is communicatively connected with the three-phase winding UVW of the motor through the SVPWM module and the drive module in turn. The acquisition module is communicatively connected with the microcontroller module and the motor information acquisition sensor.

[0046] Please refer to Figure 1 ,It is worth noting that in order to facilitate the understanding of the connection relationship between various components and modules, Figure 1 The dashed lines in the figure may represent communication connections, while the solid lines may represent electrical connections, and Figure 1 The contents shown in the figure are for example only. Without changing the circuit principle and function, the specific component types, quantities, connection sequence, etc. in the circuit can be adjusted and determined according to actual conditions, and are not limited to the above examples.

[0047] according to Figure 1It can be seen that in the discharge control circuit shown in this embodiment, the opening or closing of the first switch K1 can determine whether the DC-DC converter DCDC is connected to the circuit, the opening or closing of the bleeder resistor control switch S can determine whether the bleeder resistor R is connected to the circuit, and the opening or closing of the second switch K2 can cooperate with the above-mentioned first switch K1 and the bleeder resistor control switch S to simultaneously determine whether the DC-DC converter DCDC and the bleeder resistor R are connected to the circuit, that is, when the first switch K1 and the second switch K2 are closed at the same time, only the DC-DC converter DCDC is connected to the circuit, when the first switch K1 and the bleeder resistor control switch S are closed at the same time, only the bleeder resistor R is connected to the circuit, when the first switch K1, the second switch K2 and the bleeder resistor control switch S are closed at the same time, the DC-DC converter DCDC and the bleeder resistor R are connected to the circuit at the same time, and the opening and closing of the above-mentioned first switch K1, the second switch K2 and the bleeder resistor control switch S can be controlled by the discharge module sending relevant instructions through the communication connection.

[0048] Exemplarily, the above-mentioned vehicle controller may be, for example, a VCU (Vehicle Control Unit), the above-mentioned microcontroller module may be, for example, an MCU (Microcontroller Unit), and the above-mentioned drive module may be, for example, an IGBT (Insulated Gate Bipolar Transistor). Of course, the specific components of the above-mentioned discharge module, drive module, microcontroller module, acquisition module and vehicle controller, the specific models and performance parameters, etc. can be selected and determined according to actual conditions, and are not limited here.

[0049] The above-mentioned motor PMSM can be, for example, a motor including but not limited to a permanent magnet synchronous motor, and the motor PMSM can be controlled by the drive module issuing relevant instructions through a communication connection. Similarly, the above-mentioned motor three-phase winding UVW can be, for example, a three-phase winding of a motor including but not limited to a permanent magnet synchronous motor, and the three-phase winding UVW of the motor can also be controlled by the drive module issuing relevant instructions through a communication connection.

[0050] The information collected by the above-mentioned motor information collection sensor may include, for example, but is not limited to, motor speed, motor temperature, motor current, motor voltage and the like. Of course, the specific type of motor, the specific model and performance parameters, and the specific information collected by the above-mentioned motor information collection sensor can all be selected and determined according to actual needs and are not limited here.

[0051] The voltage monitoring point may be provided with a voltage monitoring device including but not limited to a voltage sensor, an electronic voltmeter, an electronic voltmeter, etc. with a communication function, so as to feed back the monitored voltage information to a module in a control device such as the above-mentioned discharge module, and the voltage monitoring device may monitor the voltage value at the voltage monitoring point in real time or periodically, for example, it may monitor once every 1s, every 2s, or every 3s. It is understandable that in order to feedback the voltage information at the fastest speed when the voltage changes at the voltage monitoring point, real-time monitoring may be more advantageous than periodic monitoring. The voltage value at the voltage monitoring point may be used to reflect the voltage condition at both ends of the bus capacitor C, and then reflect whether the voltage at both ends of the bus capacitor C is in a safe voltage range. Of course, what kind of voltage monitoring device is used, what kind of information is reflected by the voltage condition at both ends of the bus capacitor C, and how the voltage monitoring device monitors the voltage value at the voltage monitoring point, etc., can all be selected and determined according to actual needs, and are not limited here.

[0052] Exemplarily, the acquisition module is communicatively connected with the motor information acquisition sensor. In addition to receiving information collected by the motor information acquisition sensor, it can also determine whether there is a fault in the motor operation through the information collected by the motor information acquisition sensor. When it is determined that there is a fault in the motor operation, it can prompt the microcontroller of the motor fault. Of course, the specific functions of the acquisition module and the specific standards for determining whether there is a fault in the motor operation can all be selected and determined according to actual needs and are not limited here.

[0053] The above-mentioned communication connection can be wired communication or wireless communication, and the communication protocol used can be, for example, a communication protocol including but not limited to CAN (Controller Area Network) communication protocol, LIN (Local Interconnect Network) communication protocol, etc., and no specific limitation is made here.

[0054] The discharge control circuit provided in the embodiment of the present invention includes: a power battery P, a DC-DC converter DCDC, a first switch K1, a second switch K2, a bus capacitor C, a motor three-phase winding UVW, a motor PMSM, a motor information acquisition sensor, a discharge resistor control switch S, a discharge resistor R, and a control device. The bus capacitor C and the motor three-phase winding UVW are both connected in parallel with the power battery P, the discharge resistor R is connected in parallel between the power battery P and the motor three-phase winding UVW, the DC-DC converter DCDC is connected in parallel between the discharge resistor R and the power battery P, the discharge resistor control switch S is connected in series with the discharge resistor R, and the first switch K1, the second switch K2 and the discharge resistor control switch S are used to control whether the DC-DC converter DCDC and the discharge resistor R are connected to the circuit; different discharge methods corresponding to different motor working conditions are implemented, thereby improving the rationality, stability and efficiency of the voltage rapid release scheme of the high-voltage system of the new energy vehicle.

[0055] Further, in Figure 1 Based on the embodiment, the above discharge control circuit may further include: two voltage sensors.

[0056] The two voltage sensors are respectively arranged at the two voltage monitoring points, and are both communicatively connected with the discharge module.

[0057] and Figure 1 Similarly in the embodiment, the voltage information monitored by the above two voltage sensors can be used to reflect the voltage conditions at both ends of the bus capacitor C, and then reflect whether the voltage at both ends of the bus capacitor C is in a safe voltage range. The voltage sensor monitors the voltage value at the voltage monitoring point, which can be real-time or periodic, for example, it can be monitored every 1s, every 2s, or every 3s. It can be understood that in order to feedback the voltage information at the fastest speed when the voltage changes at the voltage monitoring point, real-time monitoring can be more advantageous than periodic monitoring. Of course, how the above voltage sensor specifically monitors the voltage value at the voltage monitoring point, etc., can be selected and determined according to actual conditions, and is not limited here.

[0058] in addition, Figure 1 Based on the embodiment, the above-mentioned discharge control circuit may further include: a low-voltage battery;

[0059] The low-voltage battery is arranged at a position close to the DC-DC converter DCDC, and the DC-DC converter DCDC is electrically connected to the low-voltage battery.

[0060] Exemplarily, the low-voltage battery can be, for example, a low-voltage battery for a car, which can be used in the DC-DC converter DCDC access circuit, and when discharging, it receives charging from the DC-DC converter DCDC, so that it can use the DC-DC converter DCDC to discharge the circuit, and can also recycle part of the energy in the discharge process to improve energy efficiency. Of course, the specific type and performance parameters of the low-voltage battery can be selected and determined according to actual conditions, and are not limited here.

[0061] Figure 2 This is a flow chart of a discharge control method provided in an embodiment of the present application. The execution subject of the method may be a vehicle controller in the above-mentioned discharge control circuit, such as Figure 2 As shown, the method includes:

[0062] S201, determine and obtain the current vehicle operation status.

[0063] For example, the current vehicle operation state may be, for example, state information including but not limited to the motor operation state, and the motor operation state may be based on, but not limited to, Figure 1 The motor speed, motor temperature, motor current, motor voltage and other motor information acquisition sensors in the embodiment are used to determine the information. Of course, what kind of status information the above-mentioned current vehicle operation status specifically includes, what specific rules are used to determine the current vehicle operation status, etc., can be selected and determined according to actual needs, and are not limited here.

[0064] S202: Send a quick discharge instruction to the discharge module according to the current vehicle operation state, wherein the quick discharge instruction is used to instruct the discharge module to determine a discharge measure and execute a discharge operation.

[0065] Exemplarily, the specific process of sending a fast discharge instruction to the discharge module according to the current vehicle operation state may be:

[0066] After the motor information acquisition sensor collects information, it is sent to the acquisition module through the communication connection. After the acquisition module determines whether there is a fault in the motor operation through the information collected by the motor information acquisition sensor, the information collected by the motor information acquisition sensor and the prompt information on whether the motor has a fault are sent to the microcontroller through the communication connection. The microcontroller processes the information from the acquisition sensor and sends it to the vehicle controller through the communication connection. The vehicle controller sends a fast discharge instruction corresponding to the current vehicle operation status to the discharge module based on the information from the microcontroller module and the preset discharge instruction sending rules. Finally, the discharge module determines the circuit elements that need to be controlled based on the fast discharge instruction, and controls these circuit elements to achieve discharge.

[0067] The processing of the information from the acquisition sensor by the above-mentioned microcontroller module may, for example, convert the information from the motor information acquisition sensor into an information format suitable for the above-mentioned vehicle controller. The above-mentioned preset discharge instruction sending rule may, for example, be that when the motor does not indicate a fault and the motor speed is less than the rated speed of the motor, the discharge is only conducted through the three-phase winding UVW of the motor in the circuit; when the motor does not indicate a fault and the motor speed is greater than the rated speed of the motor, the discharge is conducted through the three-phase winding UVW of the motor and the above-mentioned discharge resistor R; when the motor indicates a fault, the discharge is conducted through the above-mentioned discharge resistor R and the above-mentioned DC-DC converter DCDC.

[0068] It can be understood that the above contents are all examples. The specific process of sending a quick discharge instruction to the discharge module based on the current vehicle operating status, how the microcontroller module processes the information from the acquisition sensor, the actual preset discharge instruction sending rules, etc. can all be adjusted and determined according to actual needs and are not limited here.

[0069] In this embodiment, the current vehicle operation state is determined and obtained; a quick discharge instruction is sent to the discharge module according to the current vehicle operation state, and the quick discharge instruction is used to instruct the discharge module to determine the discharge measures and perform the discharge operation. By determining the current vehicle operation state obtained, the corresponding quick discharge instruction is sent according to the current vehicle operation state to determine the discharge measures and perform the discharge operation, so that the determined discharge measures and the performed discharge operation are more consistent with the current vehicle operation state, thereby improving the rationality, stability and efficiency of the voltage quick release scheme of the high-voltage system of new energy vehicles.

[0070] Further, based on the above embodiment, the sending of a quick discharge instruction to the discharge module according to the above current vehicle operation state may include:

[0071] If the current vehicle operation state is the first preset state, a first quick discharge instruction is sent to the discharge module, and the first quick discharge instruction is used to instruct to disconnect the first switch K1, the second switch K2 and the discharge resistor control switch S, and control the three-phase winding UVW of the motor to operate according to the preset current, wherein the first preset state is a state in which the motor does not indicate a fault and the motor speed is less than the rated speed of the motor.

[0072] Exemplarily, the above-mentioned motor not prompting a fault may mean that after the above-mentioned acquisition module determines that there is no fault in the operation of the motor through the information collected by the above-mentioned motor information acquisition sensor, the information collected by the above-mentioned motor information acquisition sensor and the prompt information that the motor does not have a fault are sent to the above-mentioned microcontroller module through a communication connection, and the microcontroller module processes the information from the acquisition sensor and sends it to the above-mentioned vehicle controller through a communication connection; it may also mean that only when the above-mentioned acquisition module determines that there is a fault in the operation of the motor through the information collected by the above-mentioned motor information acquisition sensor, the prompt information indicating that there is a fault in the operation of the motor is sent, and after determining that there is no fault in the operation of the motor, the relevant prompt information is not sent. When the microcontroller and the vehicle controller do not receive the prompt information that there is a fault in the operation of the motor, it is deemed that the motor does not prompt a fault. Of course, the above content is only an example, and how to determine that the motor does not prompt a fault can be selected and determined according to the actual situation, and there is no limitation here.

[0073] The motor speed being less than the motor rated speed may mean that the motor PMSM speed in the information collected by the above-mentioned motor information acquisition sensor is less than the motor rated speed. The motor rated speed may be an inherent performance parameter of the motor and may be affected by conditions such as the motor brand, model and power size. For example, it may be 3000 revolutions per minute, 6000 revolutions per minute, 12000 revolutions per minute, etc., and there is no specific limitation here.

[0074] By disconnecting the first switch K1, the second switch K2 and the discharge resistor control switch S, the DC-DC converter DCDC and the discharge resistor R are disconnected from the circuit. At this time, discharge can be achieved in the circuit only through the three-phase winding UVW of the motor.

[0075] Controlling the three-phase winding UVW of the motor to operate according to the preset current may mean that in addition to controlling the first switch K1, the second switch K2 and the discharge resistor control switch S through the communication connection, the discharge module may also control the current at the three-phase winding UVW of the motor through the micro-control module, the SVPWM module and the drive module in sequence. The current at the three-phase winding UVW of the motor may refer to the dq axis current of the motor. The specific preset current value may be calculated and determined based on actual conditions and is not limited here.

[0076] Optionally, in Figure 2 Based on the embodiment, the sending of a quick discharge instruction to the discharge module according to the current vehicle operation state may include:

[0077] If the current vehicle operation state is the second preset state, a second quick discharge instruction is sent to the discharge module, and the second quick discharge instruction is used to instruct to disconnect the first switch K1, close the second switch K2 and the discharge resistor control switch S, control the three-phase winding UVW of the motor to operate according to the preset current, and set the resistance value of the discharge resistor R to the preset resistance value, wherein the second preset state is a state in which the motor does not indicate a fault and the motor speed is greater than the rated speed of the motor.

[0078] Similar to the above-mentioned embodiment, the above-mentioned motor not prompting a fault may mean that after the above-mentioned acquisition module determines that there is no fault in the operation of the motor through the information collected by the above-mentioned motor information acquisition sensor, the information collected by the above-mentioned motor information acquisition sensor and the prompt information that there is no fault in the motor are sent to the above-mentioned microcontroller module through a communication connection, and the microcontroller module processes the information from the acquisition sensor and sends it to the above-mentioned vehicle controller through a communication connection; it may also mean that only when the above-mentioned acquisition module determines that there is a fault in the operation of the motor through the information collected by the above-mentioned motor information acquisition sensor, the prompt information indicating that there is a fault in the operation of the motor is sent, and after determining that there is no fault in the operation of the motor, the relevant prompt information is not sent, and when the microcontroller and the vehicle controller do not receive the prompt information that there is a fault in the operation of the motor, it is deemed that the motor does not prompt a fault. Of course, the above content is only an example, and how to determine that the motor does not prompt a fault can be selected and determined according to the actual situation, and is not limited here.

[0079] The motor speed being greater than the motor rated speed may mean that the motor speed in the information collected by the above-mentioned motor information acquisition sensor is greater than the motor rated speed. The motor rated speed may be an inherent performance parameter of the motor and may be affected by conditions such as the motor brand, model, and power size. For example, it may be 3000 revolutions per minute, 6000 revolutions per minute, 12000 revolutions per minute, etc., and there is no specific limitation here.

[0080] By disconnecting the first switch K1 and closing the second switch K2 and the discharge resistor control switch S, the discharge resistor R can be connected to the circuit, while the DC-DC converter DCDC is not connected to the circuit. At this time, discharge can be achieved in the circuit through the three-phase winding UVW of the motor and the discharge resistor R.

[0081] Controlling the three-phase winding UVW of the motor to operate according to the preset current may mean that in addition to controlling the first switch K1, the second switch K2 and the discharge resistor control switch S through the communication connection, the discharge module may also control the current at the three-phase winding UVW of the motor through the micro-control module, the SVPWM module and the drive module. The current at the three-phase winding UVW of the motor may refer to the DQ axis current of the motor. The specific preset current value may be determined according to actual needs and is not limited here.

[0082] Exemplarily, since the components and connection relationships of the above-mentioned discharge control circuit usually do not change, the above-mentioned setting of the resistance value of the above-mentioned discharge resistor R as a preset resistance value can refer to the calculation of the above-mentioned preset resistance value based on the parameters and connection relationships of the circuit components when the discharge resistor R is initially installed. At this time, the discharge resistor R is a fixed resistance, and there is no need to repeatedly set the resistance value each time it is subsequently connected to the circuit.

[0083] Of course, the above setting of the resistance value of the bleeder resistor R to a preset resistance value may also mean that the bleeder resistor R is a variable resistor, and each time the circuit is connected, the preset resistance value is calculated according to the parameters and connection relationship of the circuit elements in the current circuit acquired in real time, and the resistance value of the variable resistor is adjusted to the preset resistance value. It can be understood that the above contents are all examples, and how to set the resistance value of the bleeder resistor R to a preset resistance value can be determined according to actual needs and is not limited here.

[0084] In addition, Figure 2 Based on the embodiment, the sending of a quick discharge instruction to the discharge module according to the current vehicle operation state may include:

[0085] If the current vehicle operation state is the third preset state, a third quick discharge instruction is sent to the discharge module, and the third quick discharge instruction is used to instruct the closing of the first switch K1, the second switch K2 and the discharge resistor control switch S, and the resistance value of the discharge resistor R is set to a preset resistance value, wherein the third preset state is the state in which the motor indicates a fault.

[0086] Similar to the above embodiment, the above motor fault prompt may refer to the above acquisition module determining that there is a fault in the motor operation through the information collected by the above motor information acquisition sensor, sending the information collected by the above motor information acquisition sensor and the prompt information of the motor fault to the above microcontroller module through the communication connection, and the microcontroller module processes the information from the acquisition sensor and sends it to the above vehicle controller through the communication connection. Of course, the above content is only an example, and how to determine the motor fault prompt can be selected and determined according to the actual situation, and is not limited here.

[0087] By closing the first switch K1, the second switch K2 and the bleeder resistor control switch S, the DC-DC converter DCDC and the bleeder resistor R can be connected to the circuit. At this time, discharge can be achieved in the circuit through the bleeder resistor R and the DC-DC converter DCDC. Since the motor indicates a fault, the three-phase winding UVW of the motor may be out of control, and therefore the three-phase winding UVW of the motor is no longer used to achieve discharge.

[0088] Exemplarily, since the components and connection relationships of the above-mentioned discharge control circuit usually do not change, the above-mentioned setting of the resistance value of the above-mentioned discharge resistor R as a preset resistance value can refer to the calculation of the above-mentioned preset resistance value based on the parameters and connection relationships of the circuit components when the discharge resistor R is initially installed. At this time, the discharge resistor R is a fixed resistance, and there is no need to repeatedly set the resistance value each time it is subsequently connected to the circuit.

[0089] Of course, the above setting of the resistance value of the bleeder resistor R to a preset resistance value may also mean that the bleeder resistor R is a variable resistor, and each time the circuit is connected, the preset resistance value is calculated according to the parameters and connection relationship of the circuit elements in the current circuit acquired in real time, and the resistance value of the variable resistor is adjusted to the preset resistance value. It can be understood that the above contents are all examples, and how to set the resistance value of the bleeder resistor R to a preset resistance value can be determined according to actual needs and is not limited here.

[0090] The closing of the first switch K1, the second switch K2 and the discharge resistor control switch S may refer to closing the first switch K1, the second switch K2 and the discharge resistor control switch S at the same time, or may refer to closing the first switch K1 and the second switch K2 first, connecting the DC-DC converter DCDC to the circuit to realize discharge, and when the voltage monitoring device at the voltage monitoring point detects that the voltage across the bus capacitor C is reduced to a preset value, closing the discharge resistor control switch S, connecting the discharge resistor R to the circuit, and realizing discharge together with the DC-DC converter DCDC, so that the voltage across the bus capacitor C is prevented from being excessively high when the motor indicates a fault, damaging the discharge resistor R, and timely connecting the discharge resistor R after the voltage across the bus capacitor C is reduced, so as to further accelerate the discharge. Of course, how to realize the closing of the first switch K1, the second switch K2 and the discharge resistor control switch S, and to what value the voltage across the bus capacitor C is reduced to the preset value, etc., can be selected and determined according to actual conditions, and are not limited here.

[0091] Optionally, based on the above embodiment, before controlling the three-phase winding UVW of the motor to run according to a preset current, the method may further include:

[0092] The above-mentioned preset current is calculated based on the maximum safe current of the motor, the voltage across the bus capacitor C, the resistance of the three-phase winding UVW of the motor, the rotor electrical angular velocity of the motor, the permanent magnet flux value of the motor, the winding inductance value of the motor and the first preset algorithm.

[0093] For example, the specific calculation process for calculating and obtaining the above preset current based on the maximum safe current of the motor, the voltage across the bus capacitor C, the resistance of the three-phase winding UVW of the motor, the rotor electrical angular velocity of the motor, the permanent magnet flux value of the motor, the winding inductance value of the motor and the first preset algorithm can be:

[0094] According to the system safety motor three-phase winding UVW and inverter common limiting condition formula:

[0095]

[0096] Among them, the above is the motor d-axis current, which is the value to be calculated. is the motor q-axis current, which is the value to be calculated. is the maximum safe current of the motor, which is a known motor parameter and can be obtained by referring to the motor label, instruction manual, etc.

[0097] The above can be obtained The value range during discharge should be:

[0098]

[0099] According to the voltage restriction formula in the motor dq axis rotating coordinate system:

[0100]

[0101] Among them, the above is the motor d-axis voltage, which is the value to be calculated. is the motor q-axis voltage, which is the value to be calculated. is the voltage across the bus capacitor C, which is a known value monitored by the voltage monitoring device at the voltage monitoring point.

[0102] It can be obtained that the motor is in steady state and The value should be:

[0103]

[0104] Among them, the above is the resistance value of the three-phase winding UVW of the above motor, is the rotor electrical angular velocity of the motor, the above is the permanent magnet flux value of the motor, the above is the winding inductance of the motor. The above four values ​​are all known motor parameters and can be obtained by referring to the motor label, instruction manual or detecting and testing the motor.

[0105] Combining the above formulas and simplifying them, we can get the corresponding voltage limit circle equation formula:

[0106]

[0107] Since the voltage across the bus capacitor C during the discharge process is mainly from the back electromotive force of the motor, the formula can also be obtained:

[0108]

[0109] Finally, after combining the above formulas and simplifying them, we can get the above and The value should be:

[0110]

[0111] Above and The value of is also the above-mentioned preset current. It can be understood that the above-mentioned calculation process is only used as an example, and the actual preset current calculation and acquisition process is not limited to the above-mentioned calculation process.

[0112] In addition, based on the above embodiment, before setting the resistance value of the discharge resistor R to a preset resistance value, the following steps may also be included:

[0113] The preset resistance value is calculated based on the motor diode voltage drop, motor moment of inertia, motor pole pair number, bus capacitance, motor electrical angular velocity at safety voltage, motor electrical angular velocity at initial voltage, motor initial voltage, motor safety voltage and a second preset algorithm.

[0114] For example, the specific calculation formula for calculating the preset resistance value based on the motor diode voltage drop, motor rotational inertia, motor pole pair number, bus capacitance, motor electrical angular velocity at safety voltage, motor electrical angular velocity at initial voltage, motor initial voltage, motor safety voltage and second preset algorithm can be obtained based on the power size of the discharge circuit and the voltage platform of the power battery P and other characteristics:

[0115]

[0116] Among them, the above is the motor diode voltage drop, the above is the motor moment of inertia, the above is the number of motor pole pairs, the above is the busbar capacitance C, is the electrical angular velocity of the motor at a safe voltage, is the electrical angular velocity of the motor at the initial voltage, is the initial voltage of the motor, The above eight values ​​are all known motor parameters and can be obtained by referring to the motor label, instruction manual or by inspecting and testing the motor.

[0117] Above The value is the above-mentioned preset resistance value. It can be understood that the above-mentioned calculation process is only used as an example, and the actual process of calculating and obtaining the preset resistance value is not limited to the above-mentioned calculation process.

[0118] The embodiment of the present invention further provides a new energy vehicle, which may include the above-mentioned discharge control circuit. The bus capacitor C, the motor three-phase winding UVW, the motor PMSM, the motor information acquisition sensor and other components in the above-mentioned control circuit may be components of the motor of the new energy vehicle.

[0119] Figure 3 Schematic diagram of a discharge control device provided in an embodiment of the present application. The discharge control device can execute the above-mentioned discharge control method. The device can be integrated into a device with computing processing capabilities such as a computer, such as Figure 3 As shown, the device comprises:

[0120] The judgment module 310 is used to judge and obtain the current running state of the whole vehicle.

[0121] The instruction module 320 is used to send a quick discharge instruction to the discharge module according to the current vehicle operation state, and the quick discharge instruction is used to instruct the discharge module to determine a discharge measure and perform a discharge operation.

[0122] In this embodiment, the current vehicle operation state is determined and obtained; a quick discharge instruction is sent to the discharge module according to the current vehicle operation state, and the quick discharge instruction is used to instruct the discharge module to determine the discharge measures and perform the discharge operation. By determining the current vehicle operation state obtained, the corresponding quick discharge instruction is sent according to the current vehicle operation state to determine the discharge measures and perform the discharge operation, so that the determined discharge measures and the performed discharge operation are more consistent with the current vehicle operation state, thereby improving the rationality, stability and efficiency of the voltage quick release scheme of the high-voltage system of new energy vehicles.

[0123] Optionally, the instruction module 320 is specifically used to send a first quick discharge instruction to the discharge module if the current vehicle operation state is a first preset state. The first quick discharge instruction is used to instruct to disconnect the first switch K1, the second switch K2 and the discharge resistor control switch S, and control the three-phase winding UVW of the motor to operate according to a preset current, wherein the first preset state is a state in which the motor does not indicate a fault and the motor speed is less than the rated speed of the motor.

[0124] Optionally, the instruction module 320 is specifically used to send a second quick discharge instruction to the discharge module if the current vehicle operation state is a second preset state, and the second quick discharge instruction is used to instruct to disconnect the first switch K1, close the second switch K2 and the discharge resistor control switch S, control the three-phase winding UVW of the motor to operate according to a preset current, and set the resistance value of the discharge resistor R to a preset resistance value, wherein the second preset state is a state in which the motor does not indicate a fault and the motor speed is greater than the rated speed of the motor.

[0125] Optionally, the instruction module 320 is specifically used to send a third quick discharge instruction to the discharge module if the current vehicle operation state is a third preset state, and the third quick discharge instruction is used to instruct the closing of the first switch K1, the second switch K2 and the discharge resistor control switch S, and set the resistance of the discharge resistor R to a preset resistance value, wherein the third preset state is the state in which the motor indicates a fault.

[0126] Optionally, the above-mentioned device may also include: a calculation module, used to calculate and obtain the above-mentioned preset current based on the maximum safe current of the motor, the voltage across the bus capacitor C, the resistance of the three-phase winding UVW of the motor, the rotor electrical angular velocity of the motor, the permanent magnet flux value of the motor, the winding inductance value of the motor and the first preset algorithm.

[0127] Optionally, the above-mentioned calculation module is used to calculate and obtain the above-mentioned preset resistance value based on the motor diode voltage drop, the motor rotational inertia, the number of motor poles, the bus capacitance C capacity, the electrical angular velocity of the motor at a safe voltage, the electrical angular velocity of the motor at an initial voltage, the motor initial voltage, the motor safety voltage and a second preset algorithm.

[0128] The above-mentioned device is used to execute the method provided by the aforementioned embodiment, and its implementation principle and technical effect are similar, which will not be repeated here.

[0129] Figure 4 The schematic diagram of the structure of an electronic device provided in the embodiment of the present application, the electronic device may be a device with computing processing capability such as the above-mentioned computer, such as Figure 4 As shown, the device 400 includes:

[0130] Processor 410 , storage medium 420 and bus 430 . Processor 410 and storage medium 420 are communicatively connected via bus 430 .

[0131] The storage medium 420 stores machine-readable instructions executable by the processor 410 . When the electronic device is running, the processor 410 executes the machine-readable instructions to perform the discharge control method.

[0132] It should be understood that Figure 4 The structure shown is only a schematic diagram of the structure of the electronic device. The electronic device may also include Figure 4 More or fewer components as shown, or with Figure 4 Different configurations are shown. Figure 4 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0133] An embodiment of the present invention further provides a computer-readable storage medium, in which a computer program is stored. When the computer program can be executed by a processor, the discharge control method described in the above method embodiment is implemented.

[0134] The computer-readable storage medium may be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read-only memory), an EPROM, a hard disk or a ROM. Optionally, the computer-readable storage medium includes a non-transitory computer-readable storage medium. The computer-readable storage medium has a storage space for program codes for executing any method steps in the above method. These program codes may be read from or written to one or more computer program products. The program code may be compressed, for example, in an appropriate form.

[0135] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and a part of the module, program segment or code contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0136] In addition, the functional modules in the various embodiments of the present invention may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0137] If the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0138] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A discharge control circuit, characterized in that: include: A power battery, a DC-DC converter, a first switch, a second switch, a bus capacitor, a three-phase winding of a motor, a motor, a motor information acquisition sensor, a discharge resistor control switch, a discharge resistor, and a control device; wherein the control device comprises: a discharge module, a drive module, a microcontroller module, a space vector pulse width modulation SVPWM module, an acquisition module, and a vehicle controller; two voltage monitoring points are provided in the discharge control circuit, and the two voltage monitoring points are respectively arranged at positions close to both ends of the bus capacitor; The bus capacitor and the three-phase winding of the motor are both connected in parallel with the power battery, the discharge resistor is connected in parallel between the power battery and the three-phase winding of the motor, the DC-DC converter is connected in parallel between the discharge resistor and the power battery, the discharge resistor control switch is connected in series with the discharge resistor, the first switch is connected in series with the second switch, and the first switch is arranged between the DC-DC converter and the discharge resistor control switch, and the second switch is arranged between the discharge resistor control switch and the bus capacitor; The motor is arranged near the three-phase winding of the motor and is electrically connected to the three-phase winding of the motor. The motor information acquisition sensor is arranged inside the motor. The vehicle controller is communicatively connected with the discharge module and the microcontroller module, the discharge module is communicatively connected with the microcontroller module, the first switch, the second switch and the discharge resistor, the microcontroller module is communicatively connected with the three-phase winding of the motor through the SVPWM module and the drive module in sequence, and the acquisition module is communicatively connected with the microcontroller module and the motor information acquisition sensor; The vehicle controller is used to determine and obtain the current vehicle operation state; according to the current vehicle operation state, a quick discharge instruction is sent to the discharge module, and the quick discharge instruction is used to instruct the discharge module to determine the discharge measures and perform the discharge operation; The vehicle controller is specifically used for: If the current vehicle operation state is the first preset state, a first rapid discharge instruction is sent to the discharge module, wherein the first rapid discharge instruction is used to instruct to disconnect the first switch, the second switch and the discharge resistor control switch, and control the three-phase winding of the motor to operate according to a preset current, wherein the first preset state is a state in which the motor does not indicate a fault and the motor speed is less than the rated speed of the motor; or, If the current vehicle operation state is the second preset state, a second fast discharge instruction is sent to the discharge module, wherein the second fast discharge instruction is used to instruct to disconnect the first switch, close the second switch and the discharge resistor control switch, control the three-phase winding of the motor to operate according to the preset current, and set the resistance value of the discharge resistor to the preset resistance value, wherein the second preset state is a state in which the motor does not indicate a fault and the motor speed is greater than the rated speed of the motor; or, If the current vehicle operation state is the third preset state, a third quick discharge instruction is sent to the discharge module, and the third quick discharge instruction is used to instruct the closing of the first switch, the second switch and the discharge resistor control switch, and the resistance value of the discharge resistor is set to a preset resistance value, wherein the third preset state is a state in which the motor prompts a fault.

2. The discharge control circuit according to claim 1, characterized in that: The discharge control circuit further includes: two voltage sensors; The two voltage sensors are respectively arranged at the two voltage monitoring points, and are both communicatively connected with the discharge module.

3. The discharge control circuit according to claim 1, characterized in that: The discharge control circuit also includes: a low-voltage battery; The low-voltage battery is arranged at a position close to the DC-DC converter, and the DC-DC converter is electrically connected to the low-voltage battery.

4. A discharge control method, characterized in that: A vehicle controller applied to the discharge control circuit according to any one of claims 1 to 3, the method comprising: Determine and obtain the current vehicle operation status; Sending a quick discharge instruction to the discharge module according to the current vehicle operation state, wherein the quick discharge instruction is used to instruct the discharge module to determine a discharge measure and perform a discharge operation; The sending a quick discharge instruction to the discharge module according to the current vehicle operation state includes: If the current vehicle operation state is the first preset state, a first rapid discharge instruction is sent to the discharge module, wherein the first rapid discharge instruction is used to instruct to disconnect the first switch, the second switch and the discharge resistor control switch, and control the three-phase winding of the motor to operate according to a preset current, wherein the first preset state is a state in which the motor does not indicate a fault and the motor speed is less than the rated speed of the motor; or, If the current vehicle operation state is the second preset state, a second fast discharge instruction is sent to the discharge module, wherein the second fast discharge instruction is used to instruct to disconnect the first switch, close the second switch and the discharge resistor control switch, control the three-phase winding of the motor to operate according to the preset current, and set the resistance value of the discharge resistor to the preset resistance value, wherein the second preset state is a state in which the motor does not indicate a fault and the motor speed is greater than the rated speed of the motor; or, If the current vehicle operation state is the third preset state, a third quick discharge instruction is sent to the discharge module, and the third quick discharge instruction is used to instruct the closing of the first switch, the second switch and the discharge resistor control switch, and the resistance value of the discharge resistor is set to a preset resistance value, wherein the third preset state is a state in which the motor prompts a fault.

5. The method according to claim 4, characterized in that Before controlling the three-phase winding of the motor to operate according to the preset current, the method further includes: The preset current is calculated based on the maximum safe current of the motor, the voltage across the bus capacitor, the resistance of the three-phase winding of the motor, the rotor electrical angular velocity of the motor, the permanent magnet flux value of the motor, the winding inductance of the motor and the first preset algorithm.

6. The method according to claim 4, characterized in that Before setting the resistance of the discharge resistor to a preset resistance, the method further includes: The preset resistance value is calculated based on the motor diode voltage drop, motor rotational inertia, motor pole pair number, bus capacitance, motor electrical angular velocity at safety voltage, motor electrical angular velocity at initial voltage, motor initial voltage, motor safety voltage and a second preset algorithm.

7. A new energy vehicle, characterized in that: The new energy vehicle comprises the discharge control circuit described in any one of claims 1-3.

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