Motor controller, electric drive assembly and vehicle

Abstract

The embodiment of the application relates to the technical field of motor control, and discloses a motor controller, an electric drive assembly and a vehicle, the motor controller comprising: an inverter circuit, a positive short-circuit logic circuit, a first power supply branch and a second power supply branch. The inverter circuit is used for driving a motor, and the positive short-circuit logic circuit is used for controlling the inverter circuit to execute positive short-circuit. The first power supply branch is used for connecting a first power supply and providing a first working voltage, and the second power supply branch is used for connecting a second power supply and providing a second working voltage. When the first working voltage is lower than a first threshold value and the second working voltage is higher than a second threshold value, the positive short-circuit logic circuit takes power from the second power supply branch and controls the inverter circuit to execute positive short-circuit. By setting two power supply branches, the second power supply branch can be switched to continue power supply when the first power supply branch has power supply abnormity, so that the positive short-circuit function can be normally triggered, protection failure caused by power supply interruption can be avoided, and the reliability of the positive short-circuit protection is improved.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, specifically to a motor controller, an electric drive assembly, and a vehicle. Background Technology

[0002] The new energy vehicle industry is developing rapidly, and the penetration rate of electric vehicles is gradually increasing. As the core component controlling power output, the motor controller's safe and stable operation is a fundamental guarantee for vehicle operation. For electric vehicles equipped with permanent magnet synchronous motors, based on functional safety design requirements, when a fault that seriously affects driving safety occurs, the motor is generally brought to a safe state through an active short circuit (ASC).

[0003] When an electric vehicle travels at high speed, the stator and rotor of the motor rapidly cut through magnetic field lines, generating a high back electromotive force (EMF). When the three-phase inverter circuit malfunctions, the motor will switch from a power-driven state to a reverse-generating state. Excessive back EMF can damage power module components, film capacitors, and even the battery system. If the main relay disconnects and the inverter shuts down, the back EMF of the permanent magnet motor will flow back through the inverter's freewheeling device to the film capacitors in the controller, causing the capacitor voltage to rise and potentially leading to breakdown. Furthermore, when the three-phase inverter output high-voltage insulation is abnormal or the software control fails, three-phase output overcurrent can easily occur. Overcurrent can cause a rapid increase in inverter module temperature and a rapid accumulation of energy in the motor, potentially leading to inverter module damage or motor demagnetization.

[0004] Active short circuit is an effective protection method for the aforementioned faults. Active short circuit isolates the motor from the bus voltage by either turning on the upper three bridges and turning off the lower three bridges, or vice versa, when a fault occurs. This provides a discharge path for the energy stored in the motor, protecting the motor and inverter module from damage caused by energy surges. ASC (Active Short Circuit) can provide a controlled freewheeling path for the current induced by the back EMF voltage of the permanent magnet synchronous motor by simultaneously turning on all top or bottom switches of the inverter to achieve a motor short circuit.

[0005] However, in existing active short-circuit protection schemes, the power supply of the entire active short-circuit link relies too heavily on a single power supply, and the reliability of the power supply network cannot be effectively guaranteed. When the system's basic chip fails or the external low-voltage power supply is interrupted, the active short-circuit logic circuit may fail to trigger normally due to power failure, resulting in the loss of protection function. Although there are existing technologies that use isolated high-voltage flyback power supplies as emergency power supplies, they suffer from problems such as complex topology. In addition, existing solutions fail to fully address the issues of the power supply's wide coverage across the board, complex links, and high failure rate. Comprehensive logic design requires a reliable power supply topology to improve the reliability of the active short-circuit link. Therefore, a highly reliable power supply scheme is urgently needed to ensure the robustness of the motor controller's protection path. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this application is to provide a motor controller, electric drive assembly and vehicle, which aims to solve the problem of active short circuit protection failure caused by a single power supply network, system basic chip failure or external power interruption in the prior art.

[0007] In a first aspect, embodiments of this application provide a motor controller, including: an inverter circuit, an active short-circuit logic circuit, a first power supply branch, and a second power supply branch. The inverter circuit is used to drive a motor. The active short-circuit logic circuit is connected to the control terminal of the inverter circuit and is used to control the inverter circuit to perform an active short circuit.

[0008] The input terminal of the first power supply branch is connected to the first power source, and the output terminal of the first power supply branch is connected to the power supply terminal of the active short-circuit logic circuit. The input terminal of the second power supply branch is connected to the second power source, and the output terminal of the second power supply branch is connected to the power supply terminal of the active short-circuit logic circuit. The supply voltage of the second power source is greater than the supply voltage of the first power source. The first power supply branch is used to provide a first operating voltage to the active short-circuit logic circuit, and the second power supply branch is used to provide a second operating voltage to the active short-circuit logic circuit. Both the first and second operating voltages are the operating voltages of the active short-circuit logic circuit.

[0009] The active short-circuit logic circuit has a voltage detection terminal, which is connected to the output terminals of the first power supply branch and the second power supply branch, respectively, for detecting the first operating voltage and the second operating voltage. The active short-circuit logic circuit is configured to draw power from the second power supply branch and control the inverter circuit to perform an active short circuit when the voltage detection terminal detects that the first operating voltage is lower than a first threshold and the second operating voltage is higher than a second threshold.

[0010] The motor controller provided in this application provides power to the active short-circuit logic circuit via a first power supply branch and a second power supply branch. The active short-circuit logic circuit monitors the operating voltages of the two power supplies in real time via a voltage detection terminal. When the first operating voltage is detected to be lower than a first threshold and the second operating voltage is detected to be higher than a second threshold, the active short-circuit logic circuit automatically switches to the second power supply branch and controls the inverter circuit to perform an active short circuit, thus achieving automatic detection and redundant switching of the power supply source. This solution can quickly switch to the second power supply branch (high-voltage DC bus power supply) to continue supplying power to the active short-circuit logic circuit in the event of an abnormality in the first power supply branch (e.g., failure of external low-voltage power supply or voltage drop), ensuring that the active short-circuit function can be triggered normally under any abnormal power supply conditions. This effectively avoids the problem of active short-circuit protection failure due to power interruption, significantly improves the reliability of the motor controller's active short-circuit protection, and meets the vehicle's functional safety requirements for redundant power supply.

[0011] In some embodiments, the second power supply branch includes: a transformer, a power switch, a first diode, a second diode, a drive circuit, and a first capacitor. The transformer has a primary winding and a secondary winding. The first end of the primary winding is connected to the positive terminal of the second power supply, and the second end of the secondary winding is grounded. The first end of the power switch is connected to the second end of the primary winding, and the second end of the power switch is connected to the negative terminal of the second power supply. The anode of the first diode is connected to the first end of the secondary winding, the cathode of the first diode is connected to the output terminal of the second power supply branch, the cathode of the second diode is connected to the second end of the secondary winding, and the anode of the second diode is grounded. The drive circuit has a drive signal output terminal, and the control electrode of the power switch is connected to the drive signal output terminal of the drive circuit. The first end of the first capacitor is connected to the output terminal of the second power supply branch, and the second end of the first capacitor is grounded.

[0012] Based on the motor controller provided in the first aspect, this application further defines the specific circuit structure of the second power supply branch. The second power supply branch adopts a flyback converter topology. Electrical isolation between the high-voltage DC bus side and the low-voltage output side is achieved through a transformer. Energy is stored and released in the primary winding of the transformer by controlling the on / off state of the power switch. Then, through a rectifier circuit composed of the first and second diodes and the filtering effect of the first capacitor, a stable DC voltage is obtained at the output terminal. This flyback converter circuit has a simple structure, few components, and high reliability. Furthermore, the transformer itself provides electrical isolation between the primary and secondary sides, eliminating the need for additional isolation devices. This effectively meets the safety requirements of drawing power from the high-voltage DC bus and supplying power to the active short-circuit logic circuit.

[0013] In some embodiments, the second power supply branch further includes a first resistor, a second resistor, and a third resistor. A first terminal of the first resistor is connected to the positive terminal of the second power supply; a second terminal of the first resistor is connected to the first terminal of the second resistor; a second terminal of the second resistor is connected to the first terminal of the third resistor; and a second terminal of the third resistor is connected to the negative terminal of the second power supply. The drive circuit also has a power supply terminal, and the common terminal of the second and third resistors is connected to the power supply terminal of the drive circuit.

[0014] This embodiment of the application, based on the flyback converter used in the second power supply branch, further incorporates a resistor network consisting of a first resistor, a second resistor, and a third resistor. The high-voltage DC bus voltage is divided in series by these three resistors, and a voltage suitable for powering the drive circuit is extracted from across the third resistor and used as the power supply voltage for the drive circuit. This solution eliminates the need for a separate auxiliary power supply for the drive circuit; instead, it directly draws power from the high-voltage DC bus and achieves self-starting power supply through resistor voltage division. This eliminates the need for auxiliary power supply windings or separate auxiliary power supply chips, simplifying the circuit structure, reducing the number of components and cost, while simultaneously improving the circuit's integration and reliability.

[0015] In some embodiments, the second power supply branch further includes a third diode, which is connected in parallel across the third resistor. The third diode is a transient voltage suppression diode.

[0016] This embodiment of the application further adds a third diode (TVS diode) in parallel across the third resistor, building upon the existing resistor network. When a voltage spike or surge occurs on the high-voltage DC bus, the third diode quickly conducts and clamps the voltage across the third resistor within its breakdown voltage range, thereby preventing excessive voltage from entering the power supply terminal of the drive circuit and damaging the drive chip. This solution achieves overvoltage protection for the drive circuit at extremely low cost, improving the robustness and reliability of the second power supply branch under high-voltage transient environments.

[0017] In some embodiments, the second power supply branch further includes a fourth resistor, and the second terminal of the power switch is connected to the negative terminal of the second power supply through the fourth resistor. The drive circuit also has an overcurrent detection terminal, which is connected to the common terminal of the second terminal of the power switch and the fourth resistor.

[0018] In this embodiment, a fourth resistor is further provided in the second power supply branch. The second terminal of the power switch is connected to the negative terminal of the high-voltage DC bus through the fourth resistor, and the overcurrent detection terminal of the drive circuit is connected to the common terminal of the second terminal of the power switch and the fourth resistor. When the current flowing through the power switch increases, the voltage drop across the fourth resistor increases accordingly. The drive circuit monitors this voltage drop signal in real time through the overcurrent detection terminal. When the signal exceeds a preset overcurrent threshold, the drive circuit promptly shuts off the power switch to prevent excessive current from damaging the power switch and the transformer. This scheme achieves real-time detection and overcurrent protection of the output current of the second power supply branch, effectively preventing overcurrent damage caused by load short circuits, transformer saturation, or power switch failure, further improving the reliability and safety of the high-voltage power extraction circuit.

[0019] In some embodiments, the second power supply branch further includes an absorption circuit, the first end of which is connected to the first end of the primary winding, and the second end of which is connected to the second end of the primary winding.

[0020] In this embodiment, an absorption circuit is further provided in the second power supply branch. The first end of the absorption circuit is connected to the first end of the primary winding of the transformer, and the second end of the absorption circuit is connected to the second end of the primary winding of the transformer. When the power switch is turned off, the leakage inductance energy stored in the primary winding of the transformer cannot be transferred to the secondary side through normal electromagnetic coupling. If left untreated, this leakage inductance energy will generate an extremely high voltage spike at the drain (or collector) of the power switch, which may break down the power switch. The absorption circuit provides a dedicated discharge path for this leakage inductance energy, clamping the voltage spike within a safe range, thereby protecting the power switch from overvoltage damage and improving the reliability and durability of the second power supply branch during the high-frequency switching process of the power switch.

[0021] In some embodiments, the absorption circuit includes a fifth resistor, a second capacitor, and a fourth diode, wherein the fifth resistor and the second capacitor are connected in parallel and then connected in series with the fourth diode.

[0022] This application further defines the specific structure of the absorption circuit. The fifth resistor, the second capacitor, and the fourth diode constitute an RCD (resistor-capacitor-diode) absorption circuit. The fifth resistor and the second capacitor are connected in parallel, and then connected in series with the fourth diode. The RCD absorption circuit is a mature, reliable, and low-cost leakage inductance energy absorption scheme: the fourth diode conducts forward when the power switch is turned off, guiding the leakage inductance energy to the second capacitor for storage. The fifth resistor consumes the energy stored in the second capacitor, ensuring that the second capacitor has sufficient capacity to continue absorbing leakage inductance energy when the power switch is turned off again. This RCD absorption circuit has a simple structure, few components, and reliable operation. It can effectively absorb leakage inductance energy and control voltage spikes within a safe range, while avoiding the efficiency reduction problem caused by the continuous energy consumption of the resistor in a simple RC absorption circuit.

[0023] In some embodiments, the transformer also has a feedback winding, the first end of which is connected to the feedback input terminal of the drive circuit via a fifth diode, and the second end of which is grounded.

[0024] This embodiment achieves closed-loop voltage regulation control of the second power supply branch's output voltage by incorporating a feedback winding in the transformer and connecting it to the feedback input of the drive circuit via a fifth diode. This allows the drive circuit to acquire real-time output voltage changes and dynamically adjust the duty cycle. This eliminates the need for additional voltage sampling circuits and optocoupler isolation devices; the transformer's own feedback winding simultaneously provides both electrical isolation and voltage feedback. This simplifies the circuit structure, reduces component costs, ensures safe isolation between the high-voltage and low-voltage sides, improves the output voltage accuracy and load regulation of the second power supply branch, and guarantees a stable and reliable operating voltage for the active short-circuit logic circuit under various load conditions.

[0025] In some embodiments, the first power supply branch includes a first linear power supply module and a sixth diode. The input terminal of the first linear power supply module is connected to a first power supply, the output terminal of the first linear power supply module is connected to the anode of the sixth diode, and the cathode of the sixth diode is connected to the power supply terminal of the active short-circuit logic circuit.

[0026] The motor controller also includes a seventh diode, an eighth diode, and a system base chip power supply module. The output terminal of the second power supply branch is connected to the anode of the seventh diode, the cathode of the seventh diode is connected to the input terminal of the system base chip power supply module, the first output terminal of the system base chip power supply module is connected to the anode of the eighth diode, and the cathode of the eighth diode is connected to the power supply terminal of the active short-circuit logic circuit.

[0027] This embodiment further incorporates a System Base Chip (SBC) power module within the motor controller. The first power supply branch is specifically defined as a series connection of a first linear power module and a sixth diode. A seventh diode is positioned between the output of the second power supply branch and the power supply terminal of the active short-circuit logic circuit, and an eighth diode is positioned between the first output of the SBC power module and the power supply terminal of the active short-circuit logic circuit. Thus, the first power supply branch (low-voltage power supply), the second power supply branch (high-voltage DC bus power supply), and the SBC power module form a "competitive power supply" structure at the power supply terminal of the active short-circuit logic circuit via the seventh and eighth diodes. When all three are outputting normally, the branch with the higher output voltage automatically supplies power to the active short-circuit logic circuit, while the other branches are automatically cut off due to the unidirectional conduction characteristic of the diodes. This solution achieves automatic selection and seamless switching of three power supplies at extremely low cost (requiring only three diodes), eliminating the need for complex power management logic circuits. This improves power supply redundancy and reliability while maintaining the simplicity of the circuit structure.

[0028] In some embodiments, the inverter circuit includes a drive unit having a low-voltage side power supply terminal. The motor controller further includes a second linear power supply module, a ninth diode, a tenth diode, and a system base chip power supply module. The input terminal of the second linear power supply module is connected to a first power supply, the output terminal of the second linear power supply module is connected to the anode of the ninth diode, and the cathode of the ninth diode is connected to the low-voltage side power supply terminal. The cathode of the tenth diode is connected to the low-voltage side power supply terminal, and the second output terminal of the system base chip power supply module is connected to the anode of the tenth diode.

[0029] In this embodiment, a second linear power supply module is further incorporated into the motor controller. The low-voltage side power supply terminal of the inverter circuit's drive unit is connected to the output terminal of the second linear power supply module via a ninth diode, and to the second output terminal of the system base chip power supply module via a tenth diode. This creates a competitive power supply structure between the low-voltage power supply and the system base chip power supply module for the low-voltage side of the inverter circuit's drive unit. When the low-voltage power supply is normal, the second linear power supply module supplies power to the low-voltage side of the drive unit via the ninth diode; when the low-voltage power supply is abnormal or the second linear power supply module fails, the second output terminal of the system base chip power supply module automatically takes over the power supply via the tenth diode. This scheme ensures that the low-voltage side of the inverter circuit's drive unit receives a stable operating power supply under all circumstances, thereby guaranteeing that the inverter circuit can reliably perform active short-circuit operation when triggered by an active short circuit.

[0030] In some embodiments, the active short-circuit logic circuit has a first signal input terminal and a second signal input terminal. The first signal input terminal is connected to the fault signal output terminal of the microcontroller unit, and the second signal input terminal is connected to the fault signal output terminal of the power module of the system base chip.

[0031] In this embodiment of the application, the first signal input terminal of the active short-circuit logic circuit is further connected to the fault signal output terminal of the microcontroller unit (MCU), and the second signal input terminal is connected to the fault signal output terminal of the system base chip (SBC) power module. Thus, the active short-circuit logic circuit can simultaneously receive two independent fault trigger signals from the MCU and the SBC: the MCU can issue a fault signal when it detects motor operation faults such as overcurrent or overvoltage, and the SBC power module can issue a fault signal when it detects power supply faults such as overvoltage, undervoltage, or overcurrent in its own output voltage. When either fault signal is triggered, the active short-circuit logic circuit can independently control the inverter circuit to perform an active short circuit. This scheme achieves dual-path redundancy for active short-circuit triggering. Even if the MCU fails to function properly due to a fault (e.g., system crash, program crash, or power supply failure), the SBC power module can still trigger an active short circuit through independent fault detection and signal output paths; conversely, even if the power supply fault detection function of the SBC power module fails, the MCU can still trigger an active short circuit through its own fault detection. This dual-redundant fault detection and triggering mechanism significantly improves the reliability and robustness of active short-circuit protection, avoids the risk of the entire active short-circuit protection function being lost due to the failure of a single fault detection path, and better meets the requirements of the ISO 26262 functional safety standard for ASIL (Automotive Safety Integrity Level).

[0032] In some embodiments, the motor controller further includes a third power supply branch, the input of which is connected to the first power supply, and the output of which is connected to the high-voltage side power supply of the inverter circuit. The third power supply branch is used to convert the voltage provided by the first power supply into the drive voltage of the power module of the inverter circuit.

[0033] In this embodiment, a third power supply branch is further provided in the motor controller. This third power supply branch draws power from the first power source (low-voltage battery) and, after voltage conversion, provides drive voltage to the high-voltage side of the inverter circuit (i.e., the drive side of the power module). This third power supply branch is independent of the system base chip power module and the active short-circuit logic circuit. Its output is not controlled by the microcontroller or the active short-circuit logic circuit and is always in a power supply state (uncontrolled power supply). Because the third power supply branch is always in power, when an active short circuit is triggered, the power module of the inverter circuit can immediately obtain drive energy without waiting for any control signal or software response, thereby ensuring that the power module can quickly and reliably execute the active short-circuit action. At the same time, the third power supply branch is independent of other power sources on the board, and its operating state is not affected by fluctuations or faults of other power sources, avoiding interference from other power sources on the board that could affect the execution of the active short-circuit function, further improving the reliability of the active short-circuit protection.

[0034] In some embodiments, an eleventh diode is connected in series between the output terminal of the third power supply branch and the high-voltage side power supply terminal of the inverter circuit. The anode of the eleventh diode is connected to the output terminal of the third power supply branch, and the cathode of the eleventh diode is connected to the high-voltage side power supply terminal of the inverter circuit.

[0035] In this embodiment, an eleventh diode is connected in series between the output terminal of the third power supply branch and the high-voltage side power supply terminal of the inverter circuit. The eleventh diode, utilizing its unidirectional conduction characteristic, ensures that current can only flow from the third power supply branch to the high-voltage side power supply terminal of the inverter circuit, preventing pulse current or reverse induced electromotive force from the high-voltage side of the inverter circuit from flowing back into the third power supply branch. During the high-frequency switching operation of the inverter circuit, the switching action of the power module generates large voltage spikes and reverse induced electromotive force on the high-voltage side. Without isolation protection, these reverse surges can flow back into the switching power supply module of the third power supply branch, potentially causing damage or malfunction. The eleventh diode effectively blocks the reverse surge path, protecting the switching power supply module of the third power supply branch from reverse voltage surges, further improving the reliability and safety of the third power supply branch under the high-frequency switching conditions of the inverter circuit.

[0036] In some embodiments, the third power supply branch includes a switching power supply module, which is used to boost the voltage of the first power supply to the drive voltage required by the high-voltage side of the inverter circuit.

[0037] This application further defines the third power supply branch as including a switching power supply module, which is used to boost the voltage of the first power source (low-voltage battery, e.g., 12V) to the drive voltage (e.g., 15V or 18V) required by the high-voltage side of the inverter circuit. The power module of the inverter circuit typically requires a higher drive voltage to ensure the power switching transistors are fully turned on, thereby reducing on-resistance and conduction losses. The switching power supply module can efficiently boost the low-voltage input to the required high-voltage output, meeting the drive requirements of the power module. Simultaneously, the switching power supply module has higher conversion efficiency than linear power supplies, reducing energy loss and heat generation, and improving the overall efficiency and reliability of the third power supply branch. Through constant power supply, the switching power supply module is always in standby or operating state, and can promptly provide drive energy to the power module when actively short-circuited, meeting the real-time requirements of response speed and drive capability for large load drives.

[0038] Secondly, this application provides an electric drive assembly. The electric drive assembly includes: a motor and a motor controller as provided in the first aspect. The inverter circuit of the motor controller is connected to the motor.

[0039] Thirdly, this application provides a vehicle. The vehicle includes: a first power source, a second power source, and an electric drive assembly as provided in the second aspect. A first power supply branch of the motor controller is connected to the first power source, and a second power supply branch of the motor controller is connected to the second power source. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application will be described below.

[0041] Figure 1 Structural block diagrams of vehicles provided in some embodiments of this application; Figure 2 This application provides structural block diagrams of motor controllers according to some embodiments; Figure 3 Partial circuit schematics of a motor controller provided for some embodiments of this application; Figure 4 Partial circuit schematics of a motor controller provided for other embodiments of this application.

[0042] Explanation of reference numerals in the attached figures: 100 - Vehicle; 110 - Body; 120 - Primary power supply; 130 - Secondary power supply; 140 - Motor; 150 - Motor controller; 151-Inverter circuit; 1511-Drive unit; 152-Active short-circuit logic circuit; 153-System basic chip power module; 154-Micro control unit; 155-Current and voltage detection module; 156-Absorption circuit; T1 - Transformer; Np - Primary winding; Ns - Secondary winding; Nf - Feedback winding; U1 - Driver circuit; Q1 - Power switching transistor; C1 - First capacitor; C2 - Second capacitor; R1 - First resistor; R2 - Second resistor; R3 - Third resistor; R4 - Fourth resistor; R5 - Fifth resistor; D1 - First diode; D2 - Second diode; D3 - Third diode; D4 - Fourth diode; D5 - Fifth diode; D6 - Sixth diode; D7 - Seventh diode; D8 - Eighth diode; D9 - Ninth diode; D10 - Tenth diode; D11 - Eleventh diode; D12 - Twelfth diode; D13 - Thirteenth diode; LDO1 - First linear power module; LDO2 - Second linear power module. Detailed Implementation

[0043] The terms “first,” “second,” etc., are used for descriptive purposes only and have no sequential or technical meaning, nor should they be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0044] The term "electrical connection" refers to the flow of current or signal from one conductor to another. An electrical connection between A and B means that current or signal can flow from A to B and vice versa. This connection includes direct and indirect electrical connections. A direct electrical connection between A and B means that A and B are physically connected. An indirect electrical connection between A and B means that A and B are connected via C, where C can be at least one wire or device.

[0045] The embodiments of this application are described below with reference to the accompanying drawings.

[0046] Please see Figure 1 , Figure 1 Structural block diagrams of vehicles provided in some embodiments of this application.

[0047] Vehicle 100 can be, but is not limited to, pure electric vehicles (PEV / BEV), hybrid electric vehicles (HEV), range-extended electric vehicles (REEV), plug-in hybrid electric vehicles (PHEV), and new energy vehicles.

[0048] In this embodiment of the application, the vehicle 100 includes a body 110, a first power supply 120, a second power supply 130, and an electric drive assembly.

[0049] For example, the first power source 120 may be a low-voltage battery of the vehicle (including but not limited to a 12V or 24V lead-acid battery or lithium battery) for supplying power to the vehicle's low-voltage electrical system. The second power source 130 may be a power battery of the vehicle (e.g., a lithium-ion battery pack with a rated voltage of 300V to 800V) for providing high-voltage DC power to the operation of the motor 140. The supply voltage of the first power source 120 (e.g., 12V) is lower than the supply voltage of the second power source 130 (e.g., several hundred volts).

[0050] The vehicle body 110 is the main structure of the vehicle, used to support and install the various functional components of the vehicle.

[0051] For example, the first power supply 120 and the second power supply 130 are fixedly installed at the bottom of the vehicle body 110 or at the front and rear compartments.

[0052] For example, the electric drive assembly includes a motor 140 and a motor controller 150. The motor 140 is located at the front-wheel drive and / or rear-wheel drive position of the vehicle body 110 and is fixedly connected to the vehicle body 110. The motor controller 150 is located inside the vehicle body 110 and is connected to a first power supply 120, a second power supply 130 and the motor 140, respectively.

[0053] For example, the first power supply branch of the motor controller 150 is connected to the first power supply 120, the second power supply branch of the motor controller 150 is connected to the second power supply 130, and the inverter circuit of the motor controller 150 is connected to the motor 140.

[0054] The motor controller 150 is used to control the operation of the motor 140, including but not limited to controlling the motor 140 to enter an active short-circuit safety state in case of a fault. When the vehicle 100 is in normal operation, the first power supply 120 supplies power to the low-voltage control section of the motor controller 150, and the second power supply 130 provides drive power to the motor 140 through the inverter circuit of the motor controller 150. When the vehicle 100 malfunctions (e.g., a collision causing a circuit break, failure of the first power supply 120, or severe voltage fluctuations), the motor controller 150 needs to ensure that the active short-circuit function can still be triggered normally to protect the motor 140 and the inverter circuit from damage.

[0055] The vehicle 100 provided in some embodiments of this application integrates a motor controller 150 into the vehicle 100, and connects the first power supply branch of the motor controller 150 to the first power supply 120, the second power supply branch to the second power supply 130, and the inverter circuit to the motor 140, thereby achieving active short-circuit protection redundant power supply at the vehicle level. When the vehicle 100 is driving normally, the first power supply branch draws power from the first power supply 120 to power the active short-circuit logic circuit; when the first power supply 120 fails to provide power, the second power supply branch automatically draws power from the second power supply 130 to take over, ensuring that the active short-circuit logic circuit can obtain working power under any circumstances. This solution ensures that the motor controller 150 can still perform active short-circuit protection normally under various power supply abnormality scenarios at the vehicle level, effectively avoiding the risk of vehicle loss of control caused by the motor controller 150 failing to enter a safe state due to low-voltage power supply interruption, and significantly improving the driving safety of the entire vehicle.

[0056] Please see Figure 2 , Figure 2 The diagram shows the structure of a motor controller provided in some embodiments of this application.

[0057] The motor controller 150 includes an inverter circuit 151, an active short-circuit logic circuit 152, a first power supply branch, a second power supply branch, a system base chip (SBC) power module 153, a microcontroller unit (MCU) 156, and a current and voltage detection module 155.

[0058] Inverter circuit 151 is used to drive motor 140. Inverter circuit 151 includes, for example, six drive units and six power modules (power switches, such as IGBTs or MOSFETs). The six power modules form a three-phase full-bridge inverter circuit, with the high-side drive of each phase forming the upper three bridges and the low-side drive of each phase forming the lower three bridges. The six drive units are respectively connected to the control terminals of the six power modules to drive the corresponding power modules to turn on or off. The control terminals of inverter circuit 151 are connected to active short-circuit logic circuit 152. Inverter circuit 151, under the control of active short-circuit logic circuit 152, performs active short-circuit operation, that is, simultaneously turning on the upper three bridges and turning off the lower three bridges, or simultaneously turning on the lower three bridges and turning off the upper three bridges.

[0059] The active short-circuit logic circuit 152 is connected to the control terminal of the inverter circuit 151 and is used to control the inverter circuit 151 to perform an active short circuit. The active short-circuit logic circuit 152 has a power supply terminal, a voltage detection terminal, a first signal input terminal, and a second signal input terminal. The power supply terminal of the active short-circuit logic circuit 152 is used to receive the operating voltage. The voltage detection terminal of the active short-circuit logic circuit 152 is connected to the output terminals of the first power supply branch and the second power supply branch, respectively, and is used to detect the first and second operating voltages. The first signal input terminal of the active short-circuit logic circuit 152 is connected to the fault signal output terminal of the microcontroller unit 154, and the second signal input terminal is connected to the fault signal output terminal of the system base chip power module 153.

[0060] The active short-circuit logic circuit 152 is configured to: when the voltage detection terminal detects that the first operating voltage is lower than a first threshold (e.g., lower than 9V) and the second operating voltage is higher than a second threshold (e.g., higher than 10V), draw power from the second power supply branch and control the inverter circuit 151 to perform an active short circuit. Simultaneously, when the active short-circuit logic circuit 152 receives a fault signal (e.g., overcurrent fault signal or overvoltage fault signal) from the microcontroller unit 154 through the first signal input terminal, or receives a fault signal (e.g., output voltage overvoltage fault, output voltage undervoltage fault, or output overcurrent fault) from the system base chip power module 153 through the second signal input terminal, the active short-circuit logic circuit 152 also controls the inverter circuit 151 to perform an active short circuit. The active short-circuit logic circuit 152 can internally use OR logic to determine whether an active short circuit is required, provided that any fault signal is at a valid level (e.g., active low).

[0061] The input terminal of the first power supply branch is connected to the first power supply 120, and the output terminal of the first power supply branch is connected to the power supply terminal of the active short-circuit logic circuit 152. The first power supply branch is used to draw power from the first power supply 120 and provide a first operating voltage to the active short-circuit logic circuit 152. The first power supply branch may include a linear power module (e.g., a low-dropout linear regulator LDO) and a unidirectional conducting element (e.g., a diode) for converting the voltage of the first power supply 120 (e.g., 12V) into the operating voltage (e.g., 5V or 3.3V) required by the active short-circuit logic circuit 152.

[0062] The input terminal of the second power supply branch is connected to the second power supply 130, and the output terminal of the second power supply branch is connected to the power supply terminal of the active short-circuit logic circuit 152. The second power supply branch is used to draw power from the second power supply 130 and provide a second operating voltage to the active short-circuit logic circuit 152. The second power supply branch can adopt a flyback converter topology to convert the high-voltage DC power (e.g., 300V to 800V) of the second power supply 130 into low-voltage DC power (e.g., 12V or 5V) to provide backup power for the active short-circuit logic circuit 152.

[0063] The system base chip power module 153, for example, is composed of a system-on-a-chip (SoC) and peripheral circuits, integrating buck conversion, boost conversion, linear regulation, watchdog timer, fault response, and interrupt functions to form a power distribution network. The outputs of the system base chip power module 153 supply power to the current and voltage detection module 155, the microcontroller unit 154, the active short-circuit logic circuit 152, and the inverter circuit 151. The system base chip power module 153 monitors the output voltage for overvoltage, undervoltage, and overcurrent. When any of these abnormalities occur, it outputs a fault response signal to the second signal input of the active short-circuit logic circuit 152.

[0064] The microcontroller unit 154 is the main control unit of the motor controller 150, responsible for the SVPWM (Space Vector Pulse Width Modulation) algorithm of the motor 140, communication with the vehicle, and logic judgment processing. The microcontroller unit 154 collects the current and voltage signals of the inverter circuit 151 in real time through the current and voltage detection module 155. When the current exceeds the preset overcurrent threshold or the voltage exceeds the preset overvoltage threshold, it outputs a valid fault signal from its fault signal output terminal to the first signal input terminal of the active short-circuit logic circuit 152.

[0065] The current and voltage detection module 155 includes a circuit for acquiring voltage and current signals during the inverter process (e.g., a current sensor and a voltage sensor). The acquired signals are transmitted to the microcontroller unit 154 for SVPWM algorithm processing. The current and voltage detection module 155 internally has overcurrent and overvoltage signal references. While the acquired current and voltage signals are being transmitted to the microcontroller unit 154, they are also compared with the set references. If the threshold is exceeded, the microcontroller unit 154 responds to the fault and outputs a fault response signal.

[0066] The motor controller 150 provided in this embodiment supplies power to the active short-circuit logic circuit 152 via a first power supply branch and a second power supply branch, respectively. The active short-circuit logic circuit 152 monitors the operating voltages of the two power supplies in real time via a voltage detection terminal. When the first operating voltage is detected to be lower than a first threshold and the second operating voltage is detected to be higher than a second threshold, the active short-circuit logic circuit 152 automatically switches to the second power supply branch and controls the inverter circuit 151 to perform an active short circuit, thus achieving automatic detection and redundant switching of the power supply source. This scheme can quickly switch to the second power supply branch to continue supplying power to the active short-circuit logic circuit 152 in the event of an abnormal power supply from the first power supply branch, ensuring that the active short-circuit function can be triggered normally under any abnormal power supply conditions. Simultaneously, the active short-circuit logic circuit 152 receives two independent fault trigger signals from the microcontroller unit 154 and the system base chip power module 153, achieving dual-path redundancy for active short-circuit triggering. Even if the microcontroller unit 154 fails to operate normally due to a fault, the system base chip power module 153 can still trigger an active short circuit through independent fault detection and signal output paths; and vice versa. This dual-redundant fault detection and triggering mechanism significantly improves the reliability and robustness of active short-circuit protection, meeting the requirements of the ISO 26262 functional safety standard for automotive safety integrity levels.

[0067] Please see Figure 3 , Figure 3 The circuit diagram of the second power supply branch in the motor controller provided in the embodiment of this application.

[0068] In some embodiments, the second power supply branch includes: a transformer T1, a power switch Q1, a drive circuit U1, and a first capacitor C1.

[0069] Transformer T1 has a primary winding Np and a secondary winding Ns. The first terminal of the primary winding Np is connected to the positive terminal (HV+) of the second power supply 130, and the second terminal of the primary winding Np is connected to the first terminal (drain or collector) of the power switch Q1. The second terminal of the secondary winding Ns is grounded (output ground / low-voltage ground). Transformer T1 operates based on the principle of electromagnetic induction. When the power switch Q1 is turned on, the current in the primary winding Np increases and stores energy; when the power switch Q1 is turned off, the energy stored in the primary winding Np is transferred to the secondary winding Ns through magnetic field coupling.

[0070] The first terminal (drain or collector) of power switch Q1 is connected to the second terminal of the primary winding Np, and the second terminal (source or emitter) of power switch Q1 is connected to the negative terminal (HV-) of the second power supply 130. The control terminal (gate or base) of power switch Q1 is connected to the drive signal output terminal of drive circuit U1. Power switch Q1 can be a MOSFET or IGBT, and its voltage rating should be selected according to the highest voltage of the second power supply 130. For example, for a system with a rated voltage of 800V, a power switch with a voltage rating of 1200V can be selected.

[0071] The driver circuit U1 has a drive signal output terminal (OUT), which is connected to the control electrode of the power switch Q1. Driver circuit U1 is used to generate a PWM (Pulse Width Modulation) signal to drive the power switch Q1 on and off. Driver circuit U1 can be a dedicated flyback power supply control chip, such as a PWM controller integrating high-voltage start-up, overcurrent protection, and feedback regulation functions. Driver circuit U1 also has a power supply terminal (VCC) and an overcurrent detection terminal (CS).

[0072] The first terminal of the first capacitor C1 is connected to the output terminal (VOUT2) of the second power supply branch, and the second terminal of the first capacitor C1 is grounded (output ground). The first capacitor C1 is used to filter and store energy in the rectified DC voltage to ensure a stable DC voltage at the output terminal. The first capacitor C1 can be an electrolytic capacitor, and its capacitance should be selected according to the load current and output voltage ripple requirements. For example, under the condition of a load current of 100mA and an allowable ripple of 100mV, an electrolytic capacitor with a capacitance of 100μF to 470μF can be selected.

[0073] Please continue reading. Figure 3 and Figure 4In some embodiments, the second power supply branch further includes a first diode D1 and a second diode D2. The anode of the first diode D1 is connected to the first end of the secondary winding Ns, and the cathode of the first diode D1 is connected to the output terminal (VOUT2) of the second power supply branch. The cathode of the second diode D2 is connected to the second end of the secondary winding Ns, and the anode of the second diode D2 is grounded (output ground / low voltage ground).

[0074] The first diode D1 and the second diode D2 constitute a full-wave rectifier circuit, used to rectify the AC induced voltage generated by the secondary winding Ns into a DC voltage. The first diode D1 and the second diode D2 can be fast recovery diodes or Schottky diodes to reduce reverse recovery losses.

[0075] The working principle of the second power supply branch is as follows: When the drive circuit U1 outputs a high-level drive signal, the power switch Q1 is turned on, and the current from the second power supply 130 flows through the primary winding Np and the power switch Q1, storing energy in the primary winding Np. When the drive circuit U1 outputs a low-level drive signal, the power switch Q1 is turned off, and the energy stored in the primary winding Np is transferred to the secondary winding Ns through magnetic field coupling. The secondary winding Ns generates an induced electromotive force, which is rectified by the first diode D1 and the second diode D2 and then charges the first capacitor C1. The voltage across the first capacitor C1 is the output voltage of the second power supply branch. This flyback converter has a simple circuit structure, few components, and high reliability. Furthermore, the transformer T1 itself provides electrical isolation between the primary and secondary sides, eliminating the need for additional isolation devices. This effectively meets the safety requirements of drawing power from the second power supply 130 (high-voltage DC bus) and supplying power to the active short-circuit logic circuit 152.

[0076] This embodiment employs a flyback converter topology to implement the second power supply branch. Transformer T1 provides electrical isolation between the high-voltage and low-voltage sides. The on / off control of power switch Q1 allows the primary winding of transformer T1 to store and release energy. This energy is then rectified by a rectifier circuit consisting of first diode D1 and second diode D2, and filtered by first capacitor C1, resulting in a stable DC voltage at the output. This scheme is simple in structure, low in cost, and highly reliable, effectively meeting the requirements for drawing power from the high-voltage DC bus and supplying power to the active short-circuit logic circuit 152.

[0077] Please continue reading. Figure 3 and Figure 4 In some embodiments, the second power supply branch further includes a thirteenth diode D13, the anode of which is grounded (output ground / low voltage ground), and the cathode of which is connected to the output terminal (VOUT2) of the second power supply branch. The thirteenth diode D13 is connected in parallel with the first capacitor C1.

[0078] In this embodiment, a thirteenth diode D13, connected in parallel with the first capacitor C1, is further provided at the rectifier output terminal of the second power supply branch. When the power switch Q1 is turned off, the induced electromotive force generated by the secondary winding Ns of the transformer T1 is rectified by the first diode D1 and the second diode D2 and then charges the first capacitor C1. When the power switch Q1 is turned on, the induced electromotive force in the secondary winding Ns reverses, and the thirteenth diode D13 provides a freewheeling path for the secondary winding Ns, preventing the secondary winding Ns from generating excessively high reverse voltage spikes due to sudden current changes, and protecting the first diode D1 and the second diode D2 from reverse voltage impacts. At the same time, since D13 is connected in parallel with C1, D13 clamps the reverse induced electromotive force of the secondary winding Ns within a safe range, preventing the reverse voltage from superimposed on both ends of the first capacitor C1, avoiding damage to the first capacitor C1 due to overvoltage, and further improving the reliability and stability of the second power supply branch during the high-frequency switching process of the power switch.

[0079] Please continue reading. Figure 3 In some embodiments, the second power supply branch further includes: a first resistor R1, a second resistor R2, and a third resistor R3. The first end of the first resistor R1 is connected to the positive terminal (HV+) of the second power supply 130, the second end of the first resistor R1 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is connected to the first end of the third resistor R3, and the second end of the third resistor R3 is connected to the negative terminal (HV-) of the second power supply 130.

[0080] The drive circuit U1 also has a power supply terminal (VCC), and the common terminal of the second resistor R2 and the third resistor R3 is connected to the power supply terminal (VCC) of the drive circuit U1.

[0081] The first resistor R1, the second resistor R2, and the third resistor R3 are connected in series between the positive and negative terminals of the second power supply 130, forming a voltage divider circuit. The power supply terminal (VCC) of the drive circuit U1 is connected to the common terminal of the second resistor R2 and the third resistor R3, and the voltage divided from this node serves as the operating power supply for the drive circuit U1. The resistance values ​​of the first resistor R1, the second resistor R2, and the third resistor R3 should be selected according to the voltage range of the second power supply 130 and the operating voltage range of the drive circuit U1. For example, for a system with a rated DC bus voltage of 300V to 800V, the first resistor R1 can be selected as 200kΩ, the second resistor R2 as 200kΩ, and the third resistor R3 as 10kΩ, so that the voltage across the third resistor R3 is approximately 7.5V to 20V, falling within the operating voltage range of commonly used drive chips. High-voltage, high-precision metal film resistors can be used to ensure the accuracy and long-term stability of the voltage division ratio.

[0082] This embodiment uses a resistor network consisting of a first resistor R1, a second resistor R2, and a third resistor R3 to perform a series voltage divider on the high-voltage DC bus voltage of the second power supply 130, extracting a voltage suitable for powering the drive circuit U1 from across the third resistor R3. This solution eliminates the need for a separate auxiliary power supply for the drive circuit U1; instead, it directly draws power from the second power supply 130 and achieves self-starting power supply through resistor voltage division. This eliminates the need for auxiliary power supply windings or separate auxiliary power supply chips, simplifying the circuit structure, reducing the number of components and cost, while simultaneously improving the circuit's integration and reliability.

[0083] Please continue reading. Figure 3 In some embodiments, the second power supply branch further includes a third diode D3, which is connected in parallel across the third resistor R3. The third diode D3 is a transient voltage suppressor (TVS).

[0084] The third diode, D3, is an avalanche breakdown diode. Under normal operating voltage, it is in the cutoff state (high resistance state) and does not affect the voltage divider circuit. When the voltage across the third resistor R3 exceeds its breakdown voltage, the third diode D3 quickly enters the avalanche breakdown state (low resistance state), clamping the voltage near the breakdown voltage, thereby protecting the subsequent drive circuit U1. The breakdown voltage of the third diode D3 should be selected slightly higher than the maximum operating voltage of the drive circuit U1. For example, if the maximum operating voltage of the drive circuit U1 is 24V, a transient voltage suppression diode with a breakdown voltage of 24V or 27V can be selected to ensure that the circuit function is not affected during normal operation, while providing effective protection in the event of overvoltage. The third diode D3 should also have sufficient pulse power handling capability to cope with various transient overvoltage events that may occur on the second power supply 130.

[0085] When a voltage spike or surge occurs in the second power supply 130, the third diode D3 can quickly conduct and clamp the voltage across the third resistor R3 within its breakdown voltage range, thereby preventing excessive voltage from entering the power supply terminal of the drive circuit U1 and damaging the drive chip. This solution achieves overvoltage protection for the drive circuit U1 at extremely low cost, improving the robustness and reliability of the second power supply branch under high-voltage transient environments.

[0086] In some embodiments, the second power supply branch serves as the core implementation circuit of the high-voltage power extraction network, and its high-voltage side (i.e. the side connected to the second power supply 130) adopts a combination of passive devices to improve circuit robustness.

[0087] Specifically, the high-voltage side of the second power supply branch includes a voltage divider resistor network consisting of a first resistor R1, a second resistor R2, and a third resistor R3, as well as a transient voltage suppressor diode D3 connected in parallel across the third resistor R3. The voltage divider resistor network draws power from the second power supply 130 using a purely resistive voltage division method, requiring no active control devices to participate in the startup process, thus achieving completely passive self-starting power supply. The transient voltage suppressor diode D3 automatically conducts and clamps when a voltage spike or surge occurs on the high-voltage DC bus, similarly completing overvoltage protection without external control signals. Components such as transformer T1, power switch Q1, fifth resistor R5, second capacitor C2, and fourth diode D4 are all passive devices or active devices that do not require complex control; the overall high-voltage side circuit does not rely on software control or programmable logic devices.

[0088] This passive component combination scheme, because it does not rely on active controllers and software logic, eliminates startup failure issues caused by software malfunctions, program errors, or control chip failures, fundamentally improving the robustness and reliability of high-voltage power supply networks under extreme conditions. Furthermore, the resistors, diodes, capacitors, transformers, and other components in this passive component combination scheme are all mature standard components, possessing advantages such as low failure rate, strong environmental tolerance, and long service life, making them particularly suitable for applications requiring extremely high reliability, such as vehicle motor controllers.

[0089] Please continue reading. Figure 3 In some embodiments, the second power supply branch further includes a fourth resistor R4. The second terminal (source or emitter) of the power switch Q1 is connected to the negative terminal (HV-) of the second power supply 130 through the fourth resistor R4.

[0090] The drive circuit U1 also has an overcurrent detection terminal (CS), which is connected to the common terminal of the second terminal of the power switch Q1 and the fourth resistor R4.

[0091] A fourth resistor, R4, is connected in series between the source (or emitter) of the power switch Q1 and the negative terminal (HV-) of the second power supply 130, forming a low-resistance sampling resistor. When the power switch Q1 is turned on, the primary current flows through the power switch Q1 and the fourth resistor R4, generating a voltage drop signal proportional to the current across the fourth resistor R4 (V_sense = I × R4). The overcurrent detection terminal (CS) of the drive circuit U1 has an internal comparator that compares V_sense with an internal reference voltage. When V_sense exceeds the reference voltage, it is determined to be an overcurrent, and the drive signal output terminal is immediately set to a low level to turn off the power switch Q1.

[0092] The resistance value of the fourth resistor R4 should be selected based on the overcurrent protection threshold. For example, if the desired overcurrent protection threshold is 1A and the internal reference voltage is 0.5V, then the fourth resistor R4 can be selected as 0.5Ω. The fourth resistor R4 should be a low-inductance, high-precision resistor element to ensure the accuracy and fast response of overcurrent detection.

[0093] When the current flowing through the power switch Q1 increases, the voltage drop across the fourth resistor R4 also increases. The drive circuit U1 monitors this voltage drop signal in real time through the overcurrent detection terminal (CS). When the signal exceeds the preset overcurrent threshold, the drive circuit U1 promptly shuts off the power switch Q1 to prevent excessive current from damaging the power switch Q1 and the transformer T1. This scheme achieves real-time detection and overcurrent protection of the output current of the second power supply branch, effectively preventing overcurrent damage caused by load short circuits, transformer saturation, or power switch failures, further improving the reliability and safety of the high-voltage power extraction circuit.

[0094] Please continue reading. Figure 3 In some embodiments, the second power supply branch further includes an absorption circuit 156. The first end of the absorption circuit 156 is connected to the first end of the primary winding Np, and the second end of the absorption circuit 156 is connected to the second end of the primary winding Np. The absorption circuit 156 includes a fifth resistor R5, a second capacitor C2, and a fourth diode D4. The fifth resistor R5 and the second capacitor C2 are connected in parallel, and then connected in series with the fourth diode D4.

[0095] For example, the anode of the fourth diode D4 is connected to the second end of the primary winding Np (i.e., the first end of the power switch Q1), the cathode of the fourth diode D4 is connected to the parallel node of the fifth resistor R5 and the second capacitor C2, and the other end of the fifth resistor R5 and the second capacitor C2 is connected to the first end of the primary winding Np (i.e., the positive terminal HV+ of the second power supply 130).

[0096] The snubber circuit 156 is an RCD (resistor-capacitor-diode) snubber circuit, a mature, reliable, and low-cost solution for absorbing leakage inductance energy. When the power switch Q1 is turned off, the leakage inductance energy stored in the primary winding Np of the transformer T1 cannot be transferred to the secondary side through normal electromagnetic coupling. If left untreated, this leakage inductance energy will generate an extremely high voltage spike at the drain (or collector) of the power switch Q1, potentially causing the power switch Q1 to break down. The snubber circuit 156 provides a dedicated discharge path for this leakage inductance energy.

[0097] The RCD absorption circuit, consisting of the fifth resistor R5, the second capacitor C2, and the fourth diode D4, absorbs leakage inductance energy and also prevents abnormal temperature rise in transformer T1. Specifically, when the power switch Q1 is turned off, in addition to the excitation energy transferred to the secondary winding Ns via electromagnetic coupling, there is also a portion of leakage inductance energy in the primary winding Np of transformer T1 that cannot be transferred through normal coupling. If this leakage inductance energy is not handled, it will generate an extremely high reverse voltage spike across the primary winding Np. This spike may not only break down the power switch Q1 but also generate a high-frequency oscillating current in the copper wires and magnetic core of the primary winding Np, leading to increased copper and iron losses, and consequently causing abnormal temperature rise in transformer T1.

[0098] The working principle of absorption circuit 156 is as follows: When the power switch Q1 is turned off, the potential at the second terminal of the primary winding Np increases, the fourth diode D4 is forward-biased, and the leakage inductance energy charges the second capacitor C2 through the fourth diode D4, converting the voltage spike into electric field energy on the second capacitor C2, thereby clamping the voltage spike within a safe range.

[0099] When power switch Q1 is turned on, diode D4 is reverse-biased and cut off. Capacitor C2 discharges through resistor R5, dissipating the stored energy as heat (the electric field energy stored in capacitor C2 is smoothly released as heat through resistor R5), preparing for the next turn-off. The resistance of resistor R5 determines the discharge rate of capacitor C2; a smaller resistance results in faster discharge but greater losses, while a larger resistance results in less loss but may prevent C2 from fully discharging before the next turn-off. A value between 10kΩ and 100kΩ is typically chosen. The capacitance of capacitor C2 determines its absorption capacity; a larger capacitance results in stronger absorption but also greater losses. A value between 1nF and 10nF is typically chosen. Because the resistance of resistor R5 is much larger than the equivalent resistance when diode D4 is on, the release process of leakage inductance energy is prolonged, significantly reducing the peak value of the release current and preventing localized overheating caused by concentrated energy release.

[0100] This embodiment, by setting up an absorption circuit 156, clamps voltage spikes within a safe range, protecting the power switch Q1 from overvoltage damage and improving the reliability and durability of the second power supply branch during the high-frequency switching process of the power switch Q1. Compared to a scheme without an absorption circuit, leakage inductance energy forms high-frequency oscillations in the primary winding Np, and the oscillating current generates additional heat loss in the winding copper wire and magnetic core. Compared to a scheme using a simple RC absorption circuit, the unidirectional conduction characteristic of the fourth diode D4 in the RCD absorption circuit ensures that energy is absorbed only when the power switch Q1 is off and released when it is on, avoiding efficiency reduction and unnecessary temperature rise caused by the continuous energy consumption of the resistor during the power switch's conduction period. Therefore, while protecting the power switch Q1, the RCD absorption circuit effectively prevents abnormal temperature rise in the transformer T1 caused by high-frequency oscillation of leakage inductance energy or continuous energy consumption of the absorption circuit, ensuring the thermal stability and long-term reliability of the high-voltage power supply circuit under high-frequency switching conditions.

[0101] Please continue reading. Figure 3 In some embodiments, transformer T1 also has a feedback winding Nf. The first end of the feedback winding Nf is connected to the feedback input terminal (FB) of the drive circuit U1 through the fifth diode D5, and the second end of the feedback winding Nf is grounded (primary ground).

[0102] The feedback winding Nf adjusts its duty cycle based on the output voltage to stabilize it. When the output voltage of the second power supply branch changes, the induced voltage on the feedback winding Nf also changes. This change is rectified by the fifth diode D5 and transmitted to the feedback input (FB) of the drive circuit U1. The drive circuit U1 adjusts the PWM output duty cycle according to the feedback signal to maintain output voltage stability. For example, when the output voltage increases, the feedback signal increases, and the drive circuit U1 decreases the PWM duty cycle, causing the output voltage to decrease; when the output voltage decreases, the feedback signal decreases, and the drive circuit U1 increases the PWM duty cycle, causing the output voltage to increase. This feedback control achieves closed-loop regulation of the output voltage of the second power supply branch, ensuring the stability and accuracy of the output voltage.

[0103] Please see Figure 2 and Figure 4 , Figure 4 Partial circuit schematics of a motor controller provided for other embodiments of this application.

[0104] In some embodiments, such as Figure 2 and Figure 4As shown, the first power supply branch includes a first linear power module LDO1 and a sixth diode D6. The input terminal of the first linear power module LDO1 is connected to the first power supply 120, the output terminal of the first linear power module LDO1 is connected to the anode of the sixth diode D6, and the cathode of the sixth diode D6 is connected to the power supply terminal (V_ASC) of the active short-circuit logic circuit 152. The first linear power module LDO1 converts the voltage of the first power supply 120 (e.g., 12V) into the operating voltage (e.g., 5V or 3.3V) required by the active short-circuit logic circuit 152.

[0105] The motor controller 150 also includes a seventh diode D7, an eighth diode D8, and a system base chip power module 153. The output terminal (VOUT2) of the second power supply branch is connected to the anode of the seventh diode D7, the cathode of the seventh diode D7 is connected to the input terminal of the system base chip power module 153, the first output terminal of the system base chip power module 153 is connected to the anode of the eighth diode D8, and the cathode of the eighth diode D8 is connected to the power supply terminal (V_ASC) of the active short-circuit logic circuit 152.

[0106] Thus, the first power supply branch (the first linear power module LDO1 via the sixth diode D6) and the system base chip power module 153 (via the eighth diode D8) form a "competitive power supply" structure at the power supply terminal (V_ASC) of the active short-circuit logic circuit 152, i.e., a "diode-OR" redundant power supply structure. The seventh diode D7 is connected between the output terminal of the second power supply branch 154 and the input terminal of the system base chip power module 153, and is used to provide backup power to the system base chip power module 153 by drawing power from high voltage. When both the first and second power supply branches are outputting normally, the one with the higher output voltage supplies power to the active short-circuit logic circuit 152, while the other power supply branch is cut off due to the unidirectional conduction characteristic of the diode, realizing automatic selection and seamless switching of the power supply source.

[0107] A diode utilizes the unidirectional conductivity of its PN junction to achieve unidirectional current flow. When the anode voltage is higher than the cathode voltage and the difference exceeds the diode's forward voltage drop (typically 0.3V to 0.7V, depending on the diode type), the diode conducts. When the anode voltage is lower than the cathode voltage, the diode is reverse-biased and almost no current flows. Three diodes can be used: Schottky diodes can be employed to reduce the forward voltage drop (down to 0.3V to 0.5V), reducing conduction losses; fast recovery diodes can also be used to improve switching speed.

[0108] This solution achieves automatic selection and seamless switching between two power supplies at a low cost (requiring only three diodes), eliminating the need for complex power management logic circuits. This improves power supply redundancy and reliability while maintaining circuit simplicity. When the output voltage of one power supply is lower than that of the other, the corresponding diode is automatically turned off due to reverse bias, preventing backflow or interference to other power supplies and achieving mutual isolation between them.

[0109] Please continue reading. Figure 4 In some embodiments, the first power supply branch further includes a twelfth diode D12, the anode of which is connected to the first power supply 120, and the cathode of which is connected to the input terminal of the first linear power supply module LDO1.

[0110] This embodiment achieves unidirectional conduction isolation between the first power supply 120 (low-voltage battery) and the first linear power module LDO1 by setting a twelfth diode D12 in the first power supply branch. When the first power supply 120 malfunctions due to a fault (such as load dump causing severe voltage fluctuations, short circuit, or reverse polarity), the twelfth diode D12 can effectively prevent abnormal voltage or reverse current from flowing back from the first linear power module LDO1 side to the first power supply 120, preventing the abnormal state of the first power supply 120 from being conducted to the first linear power module LDO1 and its subsequent circuits, thus protecting the first linear power module LDO1 and the active short-circuit logic circuit 152 from abnormal power supply impacts. Meanwhile, the twelfth diode D12 and the sixth diode D6 together form a dual unidirectional conduction protection structure for the first power supply branch. When a short circuit fault occurs at the power supply terminal of the active short circuit logic circuit 152, the sixth diode D6 and the twelfth diode D12 together block the reverse propagation of the short circuit current to the first power supply 120 and the first linear power supply module LDO1, thereby improving the fault tolerance and reliability of the first power supply branch under various fault conditions and ensuring that the active short circuit logic circuit 152 can still obtain a stable and reliable operating voltage under abnormal power supply conditions.

[0111] Please continue reading. Figure 4 In some embodiments, the inverter circuit 151 includes a drive unit 1511 having a low-voltage side power supply terminal (VCC_LV).

[0112] The motor controller 150 also includes: a second linear power supply module LDO2, a ninth diode D9, a tenth diode D10, and a system base chip power supply module 153.

[0113] The input terminal of the second linear power supply module LDO2 is connected to the first power supply 120. The output terminal of the second linear power supply module LDO2 is connected to the anode of the ninth diode D9. The cathode of the ninth diode D9 is connected to the low-voltage side power supply terminal (VCC_LV) of the drive unit 1511. The cathode of the tenth diode D10 is connected to the low-voltage side power supply terminal (VCC_LV) of the drive unit 1511. The second output terminal of the system base chip power supply module 153 is connected to the anode of the tenth diode D10.

[0114] Therefore, the low-voltage side power supply of the drive unit 1511 of the inverter circuit 151 also forms a competing power supply structure between the first power supply 120 (via the second linear power module LDO2 and the ninth diode D9) and the system base chip power module 153 (via the tenth diode D10). When the first power supply 120 is normal, the second linear power module LDO2 supplies power to the low-voltage side of the drive unit 1511 through the ninth diode D9; when the first power supply 120 is abnormal or the second linear power module LDO2 fails, the second output terminal of the system base chip power module 153 automatically takes over the power supply through the tenth diode D10.

[0115] The inverter circuit 151 typically includes six drive units, each corresponding to a power switch transistor. The low-voltage side of the drive unit refers to the part of the drive circuit that receives control signals and low-voltage power supply; its power supply terminal requires a stable low-voltage power supply (e.g., 5V, 3.3V, or 12V, depending on the specifications of the drive chip). The second linear power module LDO2 converts the voltage of the first power supply 120 to the operating voltage required by the low-voltage side of the drive unit 1511. The second output terminal of the system base chip power module 153 can output the same or different voltages as the first output terminal to meet the power supply requirements of different loads.

[0116] This scheme ensures that the low-voltage side of the inverter circuit 151 drive unit 1511 can obtain a stable operating power supply under any circumstances, thereby ensuring that the inverter circuit 151 can reliably perform the active short-circuit action when the active short-circuit is triggered.

[0117] Please continue reading. Figure 4 In some embodiments, the motor controller 150 further includes a third power supply branch. The input of the third power supply branch is connected to the first power supply 120, and the output of the third power supply branch is connected to the high-voltage side power supply of the inverter circuit 151, for providing high-voltage drive power to the power module of the inverter circuit 151.

[0118] The third power supply branch includes a switching power supply module (e.g., a boost converter) for boosting the voltage of the first power supply 120 (e.g., 12V) to the voltage required by the high-voltage side of the inverter circuit 151 (e.g., 15V or 18V) to drive the gate or base of the power switching transistor. The third power supply branch is an uncontrolled power supply, meaning its output is not controlled by the microcontroller unit or active short-circuit logic circuit and is always in a powered state.

[0119] This embodiment sets up a third power supply branch to supply power to the high-voltage side of the inverter module, and keeps this third power supply branch in a constant power supply state (uncontrolled power supply). This allows for timely provision of drive energy to the inverter power module when an active short circuit is triggered, preventing power interruption due to control chip failure or software response delay, and ensuring that the power module can quickly execute the active short circuit action. Simultaneously, since the third power supply branch is independent of the system base chip power module and the active short circuit logic circuit, its operation is unaffected by fluctuations or failures of other power supplies on the board, effectively avoiding interference from other power supplies on the board that could affect the execution of the active short circuit function.

[0120] Please continue reading. Figure 4 In some embodiments, an eleventh diode D11 is connected in series between the output terminal of the third power supply branch and the high-voltage side power supply terminal of the inverter circuit 151. The anode of the eleventh diode D11 is connected to the output terminal of the third power supply branch, and the cathode of the eleventh diode D11 is connected to the high-voltage side power supply terminal of the inverter circuit 151. The eleventh diode D11 is used to prevent the current on the high-voltage side of the inverter circuit 151 from flowing back to the third power supply branch.

[0121] The unidirectional conduction characteristic of the eleventh diode D11 ensures that the current can only flow from the third power supply branch to the high-voltage side of the inverter circuit, preventing the pulse current or reverse induced electromotive force on the high-voltage side of the inverter circuit from flowing back into the third power supply branch, protecting the switching power supply module from reverse voltage surges, and further improving the reliability and safety of the third power supply branch.

[0122] Please continue reading. Figure 4 In some embodiments, the third power supply branch includes a switching power supply module for boosting the voltage of the first power supply 120 to the drive voltage required by the high-voltage side of the inverter circuit 151.

[0123] This embodiment further defines the third power supply branch as including a switching power supply module, which is used to boost the voltage of the first power supply 120 (low-voltage battery, e.g., 12V) to the drive voltage (e.g., 15V or 18V) required by the high-voltage side of the inverter circuit 151. Since the power modules (e.g., IGBTs or MOSFETs) of the inverter circuit 151 typically require a drive voltage higher than the output voltage of the first power supply 120 to ensure sufficient conduction of the power switching transistors, reduce on-resistance, and minimize conduction losses, the switching power supply module can efficiently boost the low-voltage input to the required high-voltage output, meeting the drive requirements of the power modules. Compared to linear power supply solutions, the switching power supply module has higher conversion efficiency, reduces energy loss and heat generation, and improves the overall efficiency and reliability of the third power supply branch. Meanwhile, the switching power supply module achieves boost conversion through constant power supply (i.e., directly drawing power from the first power supply 120 and not being controlled by any control signal), and is always in standby or working state. It can provide driving energy to the power module in a timely manner when the active short circuit is triggered, meeting the real-time requirements of response speed and driving capability for large load drives. This ensures that the power module can immediately obtain sufficient driving voltage and respond quickly at the moment of active short circuit triggering, avoiding the delay in active short circuit action caused by the delay in driving voltage establishment.

[0124] Please continue reading. Figure 2 In some embodiments, the active short-circuit logic circuit 152 has a first signal input terminal and a second signal input terminal. The first signal input terminal of the active short-circuit logic circuit 152 is connected to the fault signal output terminal of the microcontroller unit 154, and the second signal input terminal of the active short-circuit logic circuit 152 is connected to the fault signal output terminal of the system base chip power module 153.

[0125] The microcontroller unit 154 acquires the current and voltage signals of the inverter circuit 151 in real time through the current and voltage detection module 155. When the current exceeds a preset overcurrent threshold or the voltage exceeds a preset overvoltage threshold, it outputs a valid fault signal (e.g., active low) from its fault signal output terminal to the first signal input terminal of the active short-circuit logic circuit 152. The system base chip power module 153 integrates overvoltage, undervoltage, and overcurrent monitoring functions for its own output voltages. When any abnormal output voltage is detected, it outputs a valid fault signal (e.g., active low) from its fault signal output terminal to the second signal input terminal of the active short-circuit logic circuit 152.

[0126] The active short-circuit logic circuit 152 can be configured with OR logic. If either of the two fault signals is valid, an active short circuit is determined, and a corresponding control signal is output to the inverter circuit 151. The control signals output by the active short-circuit logic circuit 152 include an upper bridge arm active short-circuit control signal and a lower bridge arm active short-circuit control signal. When the upper bridge arm active short-circuit control signal is output, the upper three bridges of the inverter circuit 151 are turned on, and the lower three bridges are turned off; when the lower bridge arm active short-circuit control signal is output, the lower three bridges of the inverter circuit 151 are turned on, and the upper three bridges are turned off.

[0127] This scheme achieves dual-path redundancy for active short-circuit triggering. Even if the microcontroller unit 154 fails to function properly due to a fault (e.g., system crash, program crash, or power failure), the system base chip power module 153 can still trigger an active short circuit through independent fault detection and signal output paths. Conversely, even if the power fault detection function of the system base chip power module 153 fails, the microcontroller unit 154 can still trigger an active short circuit through its own fault detection. This dual-path redundancy fault detection and triggering mechanism significantly improves the reliability and robustness of active short-circuit protection, avoids the risk of the entire active short-circuit protection function being lost due to the failure of a single fault detection path, and better meets the requirements of the ISO 26262 functional safety standard for automotive safety integrity levels.

[0128] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Those skilled in the art can understand that implementing all or part of the processes of the above embodiments and making equivalent changes according to the claims of this application still fall within the scope of this application.

Claims

1. A motor controller (150), characterized in that, include: Inverter circuit (151) is used to drive motor (140); An active short-circuit logic circuit (152) is connected to the control terminal of the inverter circuit (151) and is used to control the inverter circuit (151) to perform an active short circuit. The first power supply branch; the input terminal of the first power supply branch is used to connect to the first power supply (120), and the output terminal of the first power supply branch is connected to the power supply terminal of the active short-circuit logic circuit (152); the first power supply branch is used to provide a first operating voltage to the active short-circuit logic circuit (152); The second power supply branch; the input terminal of the second power supply branch is used to connect to the second power supply (130), and the output terminal of the second power supply branch is connected to the power supply terminal of the active short-circuit logic circuit (152); the second power supply branch is used to provide a second operating voltage to the active short-circuit logic circuit (152); the power supply voltage of the second power supply (130) is greater than the power supply voltage of the first power supply (120); Wherein, the first operating voltage and the second operating voltage are both the operating voltages of the active short-circuit logic circuit (152); The active short-circuit logic circuit (152) has a voltage detection terminal, which is connected to the output terminal of the first power supply branch and the output terminal of the second power supply branch respectively, and is used to detect the first working voltage and the second working voltage. The active short-circuit logic circuit (152) is configured to draw power from the second power supply branch and control the inverter circuit (151) to perform an active short circuit when the voltage detection terminal detects that the first operating voltage is lower than the first threshold and the second operating voltage is higher than the second threshold.

2. The motor controller (150) according to claim 1, characterized in that, The second power supply branch includes: The transformer (T1) has a primary winding (Np) and a secondary winding (Ns); the first end of the primary winding (Np) is connected to the positive terminal of the second power supply (130), and the second end of the secondary winding (Ns) is grounded; Power switch (Q1); the first end of the power switch (Q1) is connected to the second end of the primary winding (Np), and the second end of the power switch (Q1) is connected to the negative terminal of the second power supply (130); The driving circuit (U1) has a driving signal output terminal; the control electrode of the power switch (Q1) is connected to the driving signal output terminal of the driving circuit (U1). The first capacitor (C1) has its first terminal connected to the output terminal of the second power supply branch, and its second terminal grounded.

3. The motor controller (150) according to claim 2, characterized in that, The second power supply branch also includes: a first diode (D1) and a second diode (D2); The anode of the first diode (D1) is connected to the first end of the secondary winding (Ns), and the cathode of the first diode (D1) is connected to the output terminal of the second power supply branch; The cathode of the second diode (D2) is connected to the second end of the secondary winding (Ns), and the anode of the second diode (D2) is grounded.

4. The motor controller (150) according to claim 2, characterized in that, The second power supply branch also includes: a first resistor (R1), a second resistor (R2), and a third resistor (R3); The first end of the first resistor (R1) is connected to the positive terminal of the second power supply (130), the second end of the first resistor (R1) is connected to the first end of the second resistor (R2), the second end of the second resistor (R2) is connected to the first end of the third resistor (R3), and the second end of the third resistor (R3) is connected to the negative terminal of the second power supply (130). The driving circuit (U1) also has a power supply terminal, and the common terminal of the second resistor (R2) and the third resistor (R3) is connected to the power supply terminal of the driving circuit (U1).

5. The motor controller (150) according to claim 4, characterized in that, The second power supply branch also includes: The third diode (D3) is connected in parallel across the two ends of the third resistor (R3); The third diode is a transient voltage suppression diode.

6. The motor controller (150) according to claim 2, characterized in that, The second power supply branch also includes a fourth resistor (R4), and the second terminal of the power switch (Q1) is connected to the negative terminal of the second power supply (130) through the fourth resistor (R4); The drive circuit (U1) also has an overcurrent detection terminal, which is connected to the common terminal of the second terminal of the power switch (Q1) and the fourth resistor (R4).

7. The motor controller (150) according to claim 2, characterized in that, The second power supply branch also includes an absorption circuit (156), the first end of which is connected to the first end of the primary winding (Np), and the second end of which is connected to the second end of the primary winding (Np). The absorption circuit (156) includes a fifth resistor (R5), a second capacitor (C2), and a fourth diode (D4). The fifth resistor (R5) is connected in parallel with the second capacitor (C2) and then connected in series with the fourth diode (D4).

8. The motor controller (150) according to claim 2, characterized in that, The transformer (T1) also has a feedback winding (Nf), the first end of which is connected to the feedback input terminal of the drive circuit (U1) through a fifth diode (D5), and the second end of which is grounded.

9. The motor controller (150) according to claim 1, characterized in that, The first power supply branch includes a first linear power module (LDO1) and a sixth diode (D6). The input terminal of the first linear power module (LDO1) is connected to the first power supply (120), the output terminal of the first linear power module (LDO1) is connected to the anode of the sixth diode (D6), and the cathode of the sixth diode (D6) is connected to the power supply terminal of the active short-circuit logic circuit (152). The motor controller (150) further includes a seventh diode (D7), an eighth diode (D8), and a system base chip power module (153). The output terminal of the second power supply branch is connected to the anode of the seventh diode (D7), the cathode of the seventh diode (D7) is connected to the input terminal of the system base chip power module (153), the first output terminal of the system base chip power module (153) is connected to the anode of the eighth diode (D8), and the cathode of the eighth diode (D8) is connected to the power supply terminal of the active short-circuit logic circuit (152).

10. The motor controller (150) according to claim 1, characterized in that, The inverter circuit (151) includes a drive unit (1511) having a low-voltage side power supply terminal, and the motor controller (150) further includes: The second linear power supply module (LDO2) is connected to the first power supply (120) at its input terminal. Ninth diode (D9); the output terminal of the second linear power module (LDO2) is connected to the anode of the ninth diode (D9), and the cathode of the ninth diode (D9) is connected to the low-voltage side power supply terminal; The tenth diode (D10); the cathode of the tenth diode (D10) is connected to the low-voltage side power supply terminal; System base chip power module (153); the second output terminal of the system base chip power module (153) is connected to the anode of the tenth diode (D10).

11. The motor controller (150) according to claim 1, characterized in that, The active short-circuit logic circuit (152) has a first signal input terminal and a second signal input terminal. The first signal input terminal is connected to the fault signal output terminal of the microcontroller unit (154), and the second signal input terminal is connected to the fault signal output terminal of the power module (153) of the system base chip.

12. The motor controller (150) according to claim 1, characterized in that, The motor controller (150) also includes a third power supply branch, the input end of which is connected to the first power supply (120), and the output end of which is connected to the high-voltage side power supply end of the inverter circuit (151). The third power supply branch is used to convert the voltage provided by the first power supply (120) into the driving voltage of the power module of the inverter circuit (151).

13. The motor controller (150) according to claim 12, characterized in that, An eleventh diode (D11) is connected in series between the output terminal of the third power supply branch and the high-voltage side power supply terminal of the inverter circuit (151). The anode of the eleventh diode (D11) is connected to the output terminal of the third power supply branch, and the cathode of the eleventh diode (D11) is connected to the high-voltage side power supply terminal of the inverter circuit (151).

14. An electric drive assembly, characterized in that, include: Motor (140); and, The motor controller (150) as described in any one of claims 1-13; the inverter circuit (151) of the motor controller (150) is connected to the motor (140).

15. A vehicle (100), characterized in that, include: First power supply (120); Second power supply (130); as well as The electric drive assembly as described in claim 14; The first power supply branch of the motor controller (150) is connected to the first power source (120), and the second power supply branch of the motor controller (150) is connected to the second power source (130).

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