Boost charging software control system and method for cancelling pile end voltage sampling circuit of motor controller

Abstract

The invention discloses a boost charging software control system for cancelling a pile end voltage sampling circuit of a motor controller. The boost charging software control system comprises a voltage information acquisition module which periodically acquires real-time output voltage of a charging pile through a boost distribution box and sends requested target voltage to the motor controller through a whole vehicle controller; the state management module manages the operation state of a state machine in the boost charging process through a boost charging algorithm according to a state machine instruction of the vehicle control unit on the basis of the real-time output voltage and a preset state switching condition, and a current state identifier is obtained; the power control module generates a power tube control signal through a boost charging algorithm according to the real-time output voltage, the target voltage and the current state identifier, and controls the working state of a power tube in the motor controller through the power tube control signal, thereby obtaining the adjusted output voltage. And boosting and charging the power battery according to the adjusted output voltage. According to the invention, the reliability of boost charging and the universality of equipment are improved.

Description

Technical Field

[0001] This invention relates to the fields of motor control, inverter technology, and boost charging control technology in the new energy vehicle industry, specifically to a boost charging software control system and method that eliminates the sampling circuit for the terminal voltage of the motor controller. Background Technology

[0002] Given that electric vehicles are gradually adopting 800V and above high-voltage power battery platforms to improve energy transmission efficiency and reduce charging current, while the existing public DC charging infrastructure is still mainly low-voltage charging piles with an output voltage of no more than 500V, 800V electric vehicles face technical obstacles of voltage level mismatch at the charging pile end.

[0003] Currently, most manufacturers adopt a boost charging solution that reuses existing electric drive systems to achieve safe and efficient energy transfer from low-voltage charging piles to high-voltage power batteries without adding a separate boost module. One type of existing reused boost charging system physically separates the motor controller and the boost hardware circuitry as two components. When using the electric drive function, the main control MCU chip of the motor controller runs the motor drive software; when using the boost function, the main control MCU chip of the motor controller runs the boost charging software. The boost charging algorithm requires a long hardware connection to obtain the voltage at the charging pile end, which leads to the following problems: the long line is susceptible to interference, resulting in occasional abnormalities in the sampled voltage and reduced charging reliability; the motor controller circuitry requires the addition of a high-voltage sampling circuit and isolation devices, increasing its size. Summary of the Invention

[0004] The purpose of this invention is to provide a boost charging software control system and method that eliminates the need for a motor controller terminal voltage sampling circuit. This invention improves the reliability and versatility of boost charging by replacing the hardware sampling circuit with a software control strategy.

[0005] To achieve this objective, the present invention provides a boost charging software control system that eliminates the need for a motor controller terminal voltage sampling circuit, comprising: The voltage information acquisition module is used to periodically acquire the real-time output voltage of the charging pile through the boost distribution box, and send the requested target voltage to the motor controller through the vehicle controller; The state management module is used to manage the running state of the state machine in the boost charging process according to the state machine instructions of the vehicle controller, based on the real-time output voltage and preset state switching conditions, and obtain the current state identifier through the boost charging algorithm. The power control module is used to generate a power transistor control signal based on the real-time output voltage, the target voltage, and the current status indicator through a boost charging algorithm. The power transistor control signal is used to control the operating state of the power transistor in the motor controller, thereby obtaining an adjusted output voltage. The power battery is then boost-charged based on the adjusted output voltage.

[0006] Preferably, the boost charging algorithm adopts a three-phase interleaved parallel control strategy. When the state machine is in the buck state, the three upper bridge power transistors of the motor controller are connected in interleaved parallel through the power transistor control signal, while the three lower bridge power transistors are always turned off.

[0007] Preferably, the boost charging algorithm adopts a three-phase interleaved parallel control strategy. When the state machine is in the boost state, the three lower bridge power transistors of the motor controller are connected in interleaved parallel operation through the power transistor control signal, while the three upper bridge power transistors are always turned off.

[0008] Preferably, the preset state switching conditions include voltage comparison conditions, counter conditions, and fault conditions.

[0009] Preferably, the method for obtaining the current state identifier includes: The vehicle controller sends state machine commands to the motor controller via CAN communication, and manages the operation state of the state machine during the boost charging process based on the real-time output voltage and preset state switching conditions. When charging of an electric vehicle begins, the vehicle controller sends a buck state command to the motor controller via CAN communication. At this time, the state machine is in the buck state. When the vehicle controller determines that it can start boost charging, it sends a boost state command. After the motor controller receives the boost state command, the state machine switches from the buck state to the boost state. Based on the real-time output voltage and preset state switching conditions, the boost charging algorithm determines the state machine's operating state switching according to voltage comparison conditions and counter conditions: When the state machine is in the boost-buck sub-state, it judges the difference between the target voltage requested by the vehicle controller and the real-time output voltage of the charging pile according to the voltage comparison conditions. If the target voltage is less than the real-time output voltage of the charging pile, the counter value is incremented by 1. When the counter value is greater than A, the state machine switches to the boost-wait sub-state; When the state machine is in the boost-boost sub-state, if the target voltage is higher than the real-time output voltage B of the charging pile, the state machine switches to the boost-wait sub-state. The state identifier includes the BoostSubState variable. Different values ​​of the BoostSubState variable correspond to the identifiers of the boost-buck substate, boost-wait substate, and boost-boost substate, respectively, thus obtaining the current state identifier.

[0010] Preferably, the fault condition refers to the state machine immediately jumping to the shutdown state when the motor controller detects a fault. After entering the shutdown state, the motor controller will disable the PWM output of all upper bridge power transistors and lower bridge power transistors, so that all power transistors are in the shutdown state and the boost charging process is forcibly terminated.

[0011] Preferably, the specific process of generating a power transistor control signal using a boost charging algorithm based on the real-time output voltage, the target voltage, and the current status indicator, and then controlling the operating state of the power transistor in the motor controller using the power transistor control signal to obtain the adjusted output voltage is as follows: The target voltage is subjected to a soft-start process to obtain the voltage after soft start. The current state identifier also includes a BoostDutyState variable. Different values ​​of the BoostDutyState variable correspond to the 0 duty cycle state, minimum duty cycle state, and voltage PI adjustment state in the power transistor control signal, respectively. Based on the real-time output voltage, the target voltage, and the current state identifier, a PWM duty cycle signal is generated using a boost charging algorithm. The duty cycle in the 0 duty cycle state is fixed at 0; The duty cycle in the minimum duty cycle state is set to a fixed minimum value, and the formula is: in, This represents the maximum duty cycle corresponding to the PWM period. This represents the minimum duty cycle value. Voltage PI regulation states include fixed duty cycle and PI-regulated duty cycle: The formula for calculating a fixed duty cycle is: in, To maintain a fixed duty cycle, The voltage after a soft start, This refers to the battery terminal bus voltage. K These are calibration coefficients; The duty cycle of the PI regulator is controlled in a closed loop by the PI regulator. The target voltage is compared with the real-time output voltage to obtain the error, and the PI regulator is automatically adjusted according to the error. By determining whether the state machine is in buck or boost state, it is determined whether the three upper-bridge power transistors or the three lower-bridge power transistors will operate. Then, the PWM duty cycle signal determines the conduction strength of the power transistors: for a 0 duty cycle, the power transistors are completely off; for a minimum duty cycle, the power transistors operate at low power; for voltage PI regulation, with a fixed duty cycle, the power transistors operate at a preset power; with PI regulation, the power transistors operate according to the duty cycle dynamically calculated by the PI regulator, thus obtaining the adjusted output voltage.

[0012] A boost charging software control method that eliminates the need for a motor controller's terminal voltage sampling circuit includes the following steps: The real-time output voltage of the charging pile is periodically obtained through the boost distribution box, and the target voltage is requested by the vehicle controller to the motor controller. According to the state machine instructions of the vehicle controller, based on the real-time output voltage and preset state switching conditions, the running state of the state machine in the boost charging process is managed by the boost charging algorithm to obtain the current state identifier; Based on the real-time output voltage, the target voltage, and the current status indicator, a power transistor control signal is generated through a boost charging algorithm. The power transistor control signal controls the operating state of the power transistor in the motor controller, thereby obtaining the adjusted output voltage. The power battery is then boost-charged based on the adjusted output voltage.

[0013] A computer program product includes a computer program that, when executed by a processor, implements the steps of the above-described method.

[0014] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method.

[0015] The beneficial effects of this invention are: This invention eliminates the high-voltage sampling circuit at the charging pile end of the motor controller. The motor controller periodically obtains real-time output voltage data from the boost distribution box via CAN communication. Combined with state machine management and boost charging algorithms, this avoids the problems of susceptibility to interference and low charging reliability caused by excessively long high-voltage sampling lines, significantly improving the reliability and stability of the boost charging process. This invention does not change the original circuitry and structure of the motor controller, allowing the same motor controller to be compatible with electric vehicles without boost charging functionality, improving the versatility of the equipment, and reducing costs by eliminating the need to increase the size of the motor controller. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a flowchart of the present invention; Figure 3 This is a diagram illustrating the overall system structure and strategy of the present invention. Figure 4 This is a block diagram of the boost charging software of the present invention; Figure 5 This is a flowchart of the buck control process of the present invention; Figure 6 This is a flowchart of the boost state machine of the present invention; Figure 7 This is a flowchart of the boost-buck sub-state of the present invention; Figure 8 This is a flowchart of the boost-wait sub-state of the present invention; Figure 9 This is a flowchart of the boost-boost sub-state of the present invention; Figure 10 This is a flowchart of the boost control software of the present invention; Figure 11 This is a flowchart of the boost control state machine of the present invention; Figure 12 This is a flowchart of the zero duty cycle state of the present invention; Figure 13 This is a flowchart illustrating the minimum duty cycle state of the present invention. Figure 14 This is a flowchart of the voltage PI regulation state of the present invention. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1 A boost charging software control system that eliminates the motor controller's terminal voltage sampling circuit, such as... Figure 1 As shown, it includes: The voltage information acquisition module is used to periodically acquire the real-time output voltage of the charging pile through the boost distribution box (the real-time output voltage is sent to the motor controller via the CAN bus (CAN stands for Controller Area Network, with a period of 10ms; the direct sampling circuit for the charging pile terminal voltage is eliminated here). The vehicle controller (VCU, Vehicle Control Unit) sends a requested target voltage to the motor controller (the target voltage is a voltage command value calculated by the vehicle controller based on the electric vehicle status (such as the charging requirements of the power battery and the compatibility of the charging pile)). This design, by eliminating the high-voltage sampling circuit for the charging pile terminal inside the motor controller and instead acquiring the real-time output voltage of the charging pile periodically from the boost distribution box via CAN communication (the boost distribution box has a built-in high-voltage sampling circuit that can calculate the output voltage in real time), avoids the voltage sampling abnormality problem caused by the susceptibility of long-distance hardware sampling circuits to electromagnetic interference, and improves the stability of the charging process. The state management module is used to manage the operating state of the state machine during the boost charging process according to the state machine instructions of the vehicle controller, based on the real-time output voltage and preset state switching conditions (such as voltage comparison, counter threshold and fault conditions), and obtain the current state identifier (the current state identifier includes buck state, boost state and active discharge state). This design, based on the real-time output voltage and preset state switching conditions, can ensure that the charging pile can smoothly transition under different output characteristics (such as power build-up delay of some charging piles), avoid faults caused by frequent state jumps, realize intelligent management and seamless switching of the operating state of the state machine during the boost charging process, and dynamically adapt to various charging scenarios. The power control module generates a power transistor control signal based on the real-time output voltage, the target voltage, and the current status indicator using a boost charging algorithm. This signal controls the operating state of the power transistor in the motor controller, resulting in an adjusted output voltage. The adjusted output voltage is then used to boost charge the power battery. This design employs an advanced control strategy through a boost charging algorithm, optimizing the control accuracy and efficiency of the power transistor, improving charging efficiency, and ensuring that the output voltage is consistently higher than the battery voltage, thus achieving efficient and safe boost charging.

[0018] Some preferred technical solutions include: the components of the boost charging software control system include a power battery, a high-voltage distribution box, a motor controller (MCU motor controller, full name Motor Control Unit), a motor, a boost distribution box, and a charging pile.

[0019] The operating states of the state machine include buck state, boost state, active discharge state and other states, wherein the boost state includes boost-buck sub-state, boost-wait sub-state and boost-boost sub-state; Buck state: The handshake phase of interaction between VCU and charging pile. When the MCU receives the buck request, the MCU sends a relay closing command to the boost distribution box via CAN. After the relay is closed, the MCU works in buck mode, at which time the battery pack voltage is reduced and connected to the charging pile. Boost state: When the MCU receives a boost request, it starts the boost charging action. Different charging piles on the market have different logic for establishing output voltage and power. Some charging piles can output stable power immediately, while others take a few seconds to output stable power. At the moment the boost charging action starts, in order to prevent the charging pile from reporting a fault, the boost state is further subdivided into three sub-states based on the output voltage of the charging pile and the battery bus voltage requested by the VCU. Boost-Buck sub-state: Executes boost-buck control. The control logic is the same as the buck control principle. Voltage flows from the battery pack to the charging station, with the purpose of stabilizing the output voltage of the charging station. boost-wait sub-state: The intermediate buffer state between the boost-buck sub-state and the boost-boost sub-state. When in this state, neither the buck nor the boost will run, and the power transistor will not be turned on. Boost-boost sub-state: Executes boost-boos control, which raises the output voltage of the charging pile to the battery bus voltage based on the battery bus voltage sent by the VCU, so as to charge the battery pack. Voltage and current flow from the charging pile to the battery pack. Active discharge state: After charging is completed, the high voltage network of the charging pile and battery pack is disconnected. The capacitors of the power distribution box and motor controller still have high voltage. At this time, the MCU sends a discharge command to the boost power distribution box, and the power distribution box controls the on and off of the relay to achieve the purpose of high voltage discharge. Other states: The state of boost charging not started and charging finished. When in this state, the relay of the boost distribution box is disconnected and the power transistor is in the off state.

[0020] Some preferred technical solutions include: the boost charging algorithm adopts a three-phase interleaved parallel control strategy. When the state machine is in the buck state, the three upper bridge power transistors of the motor controller are interleaved and paralleled through the power transistor control signal, while the three lower bridge power transistors are always off. The above design connects three identical buck circuits (corresponding to three upper bridge power transistors) in parallel and makes the PWM drive signals of the three upper bridge power transistors work with a phase difference of 120 degrees. This can reduce the stress on the battery and circuit components, improve charging quality and stability, and increase charging efficiency.

[0021] Some preferred technical solutions include: the boost charging algorithm adopts a three-phase interleaved parallel control strategy. When the state machine is in the boost state, the three lower bridge power transistors of the motor controller are interleaved and paralleled through the power transistor control signal, while the three upper bridge power transistors are always off. The above design, by acting on the three lower bridge power transistors of the boost circuit, allows the three lower bridge transistors to work interleaved with a 120-degree phase difference, while the three upper bridge power transistors are always off. This can significantly reduce the input current ripple, reduce the stress on the battery and circuit components, improve charging quality and stability, and increase charging efficiency.

[0022] Some preferred technical solutions include: the preset state switching conditions include voltage comparison conditions, counter conditions and fault conditions; the above design improves stability and security by constructing a multi-level, highly reliable, and real-time responsive and stable intelligent state switching management mechanism.

[0023] In some preferred embodiments, the method for obtaining the current state identifier includes: The vehicle controller sends state machine commands (including buck and boost state commands) to the motor controller via CAN communication. Based on the real-time output voltage and preset state switching conditions, it manages the operating state of the state machine during the boost charging process. When charging of an electric vehicle begins, the vehicle controller sends a buck state command to the motor controller via CAN communication. At this time, the state machine is in the buck state. When the vehicle controller determines that it can start boost charging, it sends a boost state command. After the motor controller receives the boost state command, the state machine switches from the buck state to the boost state. Based on the real-time output voltage and preset state switching conditions, the boost charging algorithm determines the state machine's operating state switching according to voltage comparison conditions and counter conditions: When the state machine is in the boost-buck sub-state, it judges the difference between the target voltage requested by the vehicle controller and the real-time output voltage of the charging pile according to the voltage comparison conditions. If the target voltage is less than the real-time output voltage of the charging pile, the counter value is incremented by 1. When the counter value is greater than A (A=100), the state machine switches to the boost-wait sub-state; When the state machine is in the boost-boost sub-state, if the target voltage is higher than the real-time output voltage B (B=15V) of the charging pile, the state machine switches to the boost-wait sub-state. The status identifier includes the BoostSubState variable (the BoostSubState variable is the Boost sub-state identifier, used for switching between boost states). Different values ​​of the BoostSubState variable correspond to the identifiers of the boost-buck sub-state, boost-wait sub-state, and boost-boost sub-state, respectively, thus obtaining the current status identifier. The above design, through the collaborative division of labor between the vehicle controller and the motor controller, constructs a hierarchical, precise, and highly reliable boost charging status management mechanism, realizing the timeliness, stability, and safety of boost switching during charging, and improving the efficiency and reliability of boost charging.

[0024] The status identifier also includes the BoostDutyState variable, which is used for duty cycle state switching.

[0025] For fault conditions, some preferred technical solutions include: the fault condition refers to the situation where the motor controller detects a fault (motor controller overheating, bus overvoltage, hardware overcurrent, or driver chip bridge arm), and the state machine immediately jumps to the shutdown state. After entering the shutdown state, the motor controller will disable the PWM output of all upper and lower bridge power transistors, putting all power transistors in the shutdown state, and the boost charging process is forcibly terminated. The above design, by setting the fault condition with the highest priority, can unconditionally and immediately force the device to enter the shutdown state when a serious fault occurs, thereby maximizing the prevention of permanent equipment damage and avoiding safety accidents.

[0026] In some preferred embodiments, the process of generating a power transistor control signal using a boost charging algorithm based on the real-time output voltage, the target voltage, and the current state identifier, and then controlling the operating state of the power transistor in the motor controller using the power transistor control signal to obtain the adjusted output voltage is as follows: The target voltage is subjected to a soft-start process to obtain the voltage after soft start. The current state identifier also includes a BoostDutyState variable. Different values ​​of the BoostDutyState variable correspond to the 0 duty cycle state, minimum duty cycle state, and voltage PI adjustment state in the power transistor control signal, respectively. Based on the real-time output voltage, the target voltage, and the current state identifier, a PWM duty cycle signal is generated using a boost charging algorithm. The duty cycle in the 0 duty cycle state is fixed at 0; The duty cycle in the minimum duty cycle state is set to a fixed minimum value, and the formula is: in, This represents the maximum duty cycle corresponding to the PWM period. This represents the minimum duty cycle value. The voltage PI regulation states include fixed duty cycle (fixed duty cycle is mode 1) and PI regulation duty cycle (PI regulation duty cycle is mode 2): The formula for calculating a fixed duty cycle is: in, To maintain a fixed duty cycle, The voltage after a soft start, This refers to the bus voltage at the battery terminal (the voltage between the positive and negative terminals of the power battery pack). K These are calibration coefficients (obtained through calibration on electric vehicles). K (Value 0.8) The PI regulation duty cycle is controlled in a closed loop by a PI regulator (proportional-integral regulator). The target voltage is compared with the real-time output voltage to obtain the error, and the PI regulator is automatically adjusted according to the error. By determining whether the state machine operates in buck or boost mode, it controls whether the three upper-bridge power transistors or the three lower-bridge power transistors are active. The PWM duty cycle signal then determines the conduction strength of the power transistors: for a 0 duty cycle, the power transistors are completely off; for a minimum duty cycle, they operate at low power; and for PI regulation, with a fixed duty cycle, the power transistors operate at a preset power, while with PI regulation, they operate according to the dynamically calculated duty cycle by the PI regulator, resulting in an adjusted output voltage. This adjusted output voltage is boosted through the motor controller's power circuit, ultimately reaching a value higher than the battery voltage. The boosted output voltage is then directly applied to the battery through the high-voltage distribution box to complete charging. This design, by introducing a multi-mode, phased duty cycle control strategy, achieves precise, smooth, and adaptive control of the power transistors' operating state during boost charging. This improves the output voltage regulation accuracy, dynamic response speed, and adaptability to different operating conditions, enabling efficient and reliable boost charging.

[0027] For the voltage after a soft start, some preferred technical solutions include: after receiving the target voltage requested by the VCU, the motor controller (MCU) generates a ramp signal through an algorithm called "soft start processing" or "ramp function", thereby gradually and linearly increasing the target voltage from the current voltage value to the target value according to a preset slope. The target value is the voltage after the soft start.

[0028] Example 2 A boost charging software control method that eliminates the need for the motor controller's terminal voltage sampling circuit, such as... Figure 2 As shown, the real-time output voltage of the charging pile is periodically acquired through the boost distribution box, and the target voltage is requested by the vehicle controller to the motor controller. According to the state machine instructions of the vehicle controller, based on the real-time output voltage and preset state switching conditions, the running state of the state machine of the boost charging process is managed by the boost charging algorithm to obtain the current state identifier. According to the real-time output voltage, target voltage and current state identifier, the power transistor control signal is generated by the boost charging algorithm. The working state of the power transistor in the motor controller is controlled by the power transistor control signal to obtain the adjusted output voltage. The power battery is boost charged according to the adjusted output voltage.

[0029] The specific methods for controlling boost charging software include the following steps: The real-time output voltage of the charging pile is periodically obtained through the boost distribution box, and the target voltage is requested by the vehicle controller to the motor controller. According to the state machine instructions of the vehicle controller, based on the real-time output voltage and preset state switching conditions, the running state of the state machine in the boost charging process is managed by the boost charging algorithm to obtain the current state identifier; Based on the real-time output voltage, the target voltage, and the current status indicator, a power transistor control signal is generated through a boost charging algorithm. The power transistor control signal controls the operating state of the power transistor in the motor controller, thereby obtaining the adjusted output voltage. The power battery is then boost-charged based on the adjusted output voltage.

[0030] Example 3 This invention proposes a new software control strategy for boost charging that eliminates the need for the motor controller's terminal voltage sampling circuit, comprising the following steps: like Figure 3 The diagram below further illustrates the overall structure and strategy block diagram of the boost charging software control system: The entire boost charging software control system includes components such as power battery, high voltage distribution box, motor controller, motor, boost distribution box and charging pile; Step S101 involves the car's power battery. The battery pack voltage may vary depending on the car model, so the output voltage of the boost charger must be within a certain range. Step S102 is the high-voltage distribution box of the car. One end is connected to the battery pack through a relay, and the other end is connected to various high-voltage components. The negative terminal of the distribution box is connected to the negative terminal of the step-up distribution box. Step S103 is the motor controller of the powertrain. The motor controller includes structure, software and hardware. The cancellation of the high voltage sampling circuit at the charging pile end mentioned in this invention means that there is no boost distribution box or high voltage sampling circuit for the charging pile on the hardware circuit of the motor controller, and there is no corresponding ADC sampling channel configured in the software. The corresponding charging pile end voltage is obtained through CAN communication. Step S104 is the motor of the powertrain. The three-phase stator inductance of the motor will be used in the entire circuit of boost charging. Step S105 is the step-up distribution box. The main components inside the step-up distribution box are MCU (Motor Control Unit) control board, inductors, relays, capacitors and high voltage sampling circuit. The MCU control board has a microprocessor that interacts with the motor controller via CAN and controls the relay to close and close. In vehicle driving mode, the relays between the boost distribution box and the motor, and between the boost distribution box and the high-voltage distribution box, are all disconnected. The power battery is connected to the motor controller through the high-voltage distribution box, and the motor controller controls the motor to run, thereby driving the vehicle. The relays mentioned in this invention are relays for the positive and negative terminals of the busbar, including relays for the charging pile and the step-up distribution box, and relays for the step-up distribution box and the motor. All relays are placed inside the step-up distribution box. In boost charging mode, all components are connected, and the motor controller increases the output voltage of the charging pile to charge the power battery. During the boost charging process, the boost control algorithm of the motor controller needs to know the real-time output voltage information of the charging pile. The boost distribution box has a high-voltage sampling circuit to calculate the output voltage of the charging pile in real time and send it to the motor controller via CAN, with a cycle of 10ms. Buck and boost employ a three-phase interleaved parallel control strategy. In buck control, the three upper-bridge power transistors of the motor controller operate in interleaved parallel connection, while the three lower-bridge power transistors remain constantly off. In boost control, the three lower-bridge power transistors of the motor controller operate in interleaved parallel connection, while the three upper-bridge power transistors remain constantly off. Step S106 is the charging station.

[0031] like Figure 4 The following is a further explanation of the boost charging software block diagram: In step S201, the MCU obtains the state machine instructions sent by the VCU (Vehicle Control Unit) through CAN communication. There are four state machines related to the boost charging algorithm logic: buck state, boost state, active discharge state, and other states. In step S202, the MCU receives the buck status command; Step S203, the handshake phase of VCU and charging pile interaction: When the MCU receives the Buck request, the MCU sends a relay closing command to the boost power distribution box via CAN. Only after the relay is closed will the MCU work in Buck mode, at which time the battery pack voltage is reduced and connected to the charging pile. Step S204: The MCU operates in buck mode; In step S205, the MCU receives the boost status instruction. When the MCU receives the boost request, the system starts the boost charging action. Different charging piles on the market have different logic for establishing output voltage and power. Some charging piles can output stable power immediately, while others take a few seconds to output stable power. At the moment the boost charging action starts, in order to prevent the charging pile from reporting a fault, the boost state is further subdivided into three sub-states based on the output voltage of the charging pile and the target voltage requested by the VCU. Step S206, boost-buck sub-state: execute boost-buck control. The control logic is the same as the buck control principle. The voltage flows from the battery pack to the charging pile, with the purpose of stabilizing the output voltage of the charging pile. In step S207, the MCU executes boost-buck control; Step S208, boost-wait sub-state: the intermediate buffer state between the boost-buck sub-state and the boost-boost sub-state. When in this state, neither the buck nor the boost will run, and the power transistor will not be turned on. Step S209: The MCU performs a power-off action; Step S210, boost-boost sub-state: execute boost-boost control, according to the target voltage sent by VCU, increase the output voltage of the charging pile to the target value, so as to charge the battery pack. Voltage and current flow from the charging pile to the battery pack. Step S211: The MCU executes boost control; Step S212, Active Discharge State: After charging is completed, the high voltage network of the charging pile and battery pack is disconnected, but the capacitors of the power distribution box and motor controller still have high voltage. In step S213, the MCU sends a discharge command to the boost distribution box, and the distribution box controls the on / off state of the relay to achieve the purpose of high-voltage discharge; Step S214, other states: boost charging not started and charging ended; Step S215: When in this state, disconnect the relay of the boost distribution box; Step S216: Perform the power transistor shutdown action, and the power transistor is in the off state.

[0032] like Figure 5 The diagram below further illustrates the Buck control flow chart. In step S301, after receiving the buck command from the VCU, the MCU first closes the relay in the boost distribution box to ensure that the high-voltage network of each component in the system is properly connected, and then runs the buck control software. If the relay is not closed, the buck control software cannot run. Step S302: After the relay is closed, determine whether a serious fault has occurred. Here, a serious fault refers to a fault that affects the control of buck and boost and has the risk of damaging the motor controller, including controller overheating, bus overvoltage, hardware overcurrent, driver chip bridge arm failure, etc. A fault has occurred: EmergeStopEnb_flg=TRUE; No fault occurred: EmergeStopEnb_flg=FALSE; In step S303, when a fault occurs, the motor controller performs a shutdown action to disable the PWM output of the upper and lower bridges; Step S304: If there is no fault, read the target voltage requested by the VCU and the charging pile terminal voltage, and enter buck voltage control. The target voltage is sent from the VCU to the MCU via CAN communication, with a transmission cycle of 10ms. The voltage at the charging pile end is calculated by sampling from the boost distribution box. The sampling circuit is located inside the distribution box, and this part of the circuit has been removed from the motor controller. The voltage is then sent to the MCU via CAN, with a transmission cycle of 10ms. Step S305, Buck voltage control, specifically described as: determining whether the charging pile output voltage is higher than the VCU's requested target voltage by more than 1V; Step S306: If the condition is met, then perform the shut-off action; In step S307, if the condition is not met, the three power transistors of the lower bridge are turned on M times consecutively, and then turned off N times, alternating between turning on and off. The values ​​of M and N are obtained through calibration on the vehicle and are related to the voltage requested by the VCU. The values ​​of M and N are different depending on the voltage. For reference, M=3 and N=4 can be taken.

[0033] like Figure 6 The following provides a further explanation of the Boost state machine flowchart: The boost state is logically divided into three sub-states: boost-buck, boost-wait, and boost-boost. The boost-buck sub-state is when the system is working in buck mode; the boost-wait sub-state is the intermediate switching process state; and the boost-boost sub-state is when the system is working in boost mode. Step S401, boost-buck sub-state: when BoostSubState = boost-wait, the state jumps to boost-wait.

[0034] Step S402, boost-wait sub-state: when BoostSubState = boost-boost, the state transitions to boost-boost; when BoostSubState = boost-buck, the state transitions to boost-buck. Step S403, boost-boost sub-state: when BoostSubState = boost-wait, the state jumps to boost-wait.

[0035] like Figure 7 The following further illustrates the sub-state flowchart of Boost-Buck: Step S501, in the boost-buck sub-state; Step S502: Determine whether the target voltage requested by the VCU is less than the charging pile terminal voltage; Step S503: If the condition is met, increment the count value by 1; Step S504: If the condition is not met, the count value is reset to zero. Step S505: Determine if the count value is greater than 100. If the condition is not met, no operation will be performed within this task cycle. Step S506, the condition is met, BoostSubState = boost-wait.

[0036] like Figure 8 The following further illustrates the boost-wait sub-state flowchart: In step S601, during the boost-wait sub-state, all power transistors of the upper and lower bridges are turned off and are in the off state. Step S602: Determine whether the target voltage requested by the VCU is less than the charging pile terminal voltage; Step S603: If the target voltage is less than the terminal voltage, increment the count value BOOST_waitCnt1 by 1 and clear BOOST_waitCnt2 to zero. Step S604: Determine whether BOOST_waitCnt1 is greater than 2. If the condition is not met, no action will be performed during this task cycle. Step S605: If the condition is met, BoostSubState = boost-boost; Then the BOOST_waitCnt1 counter value is cleared to zero; Step S606: If the target voltage is not less than the charging pile terminal voltage, then the count value BOOST_waitCnt2 is incremented by 1 and BOOST_waitCnt1 is cleared. Step S607: Determine whether BOOST_waitCnt2 is greater than 2. If the condition is not met, no action will be performed during this task cycle. Step S608: If the condition is met, BoostSubState = boost-buck; Then the BOOST_waitCnt2 counter value is cleared to zero.

[0037] like Figure 9 The following further illustrates the boost-boost sub-state flowchart: Step S701, in the boost-boost sub-state; Step S702: Determine whether the target voltage requested by the VCU is more than 15V higher than the charging pile terminal voltage. If the condition is not met, remain in this sub-state and execute boost control; Step S703: If the condition is met, BoostSubState = boost-wait, and return to the boost-wait substate.

[0038] like Figure 10 The following is a further explanation of the boost control software flowchart: Step S801: Enter the boost-boost sub-state; Step S802: Determine if there is a fault. Note that the fault variable here is the same as the fault variable mentioned in the buck state. In step S803, when a fault occurs, the motor controller performs a shutdown action to disable the PWM output of the upper and lower bridges; In step S804, when there is no fault, the MCU receives the requested voltage from the VCU. The voltage increases at a set slope, i.e., the voltage command is soft-started. The voltage rise slope value is obtained by calibration on the vehicle. To further explain, depending on the state in which the software is running, the corresponding state logic is executed. There are three states: 0 duty cycle state, minimum duty cycle state, and voltage PI regulation state. To further clarify, the software initially runs in a 0 duty cycle state by default; Step S805, 0 duty cycle state means that the duty cycle of the PWM is a fixed value of 0; Step S806, the minimum duty cycle state is that the duty cycle of the PWM is a fixed minimum value; In step S807, the voltage PI regulation state is obtained by real-time calculation of the PWM duty cycle through the PI regulator; To further explain, the formula for calculating the minimum duty cycle limit here is: , in, This represents the maximum duty cycle corresponding to the PWM period. This represents the minimum duty cycle.

[0039] like Figure 11 The following further illustrates the flowchart of the boost control state machine: The software variable for the three state transitions is BoostDutyState; Step S901, 0 duty cycle state. When BoostDutyState = 2, the state jumps to the minimum duty cycle state. Step S902, minimum duty cycle state: when BoostDutyState = 3, the state jumps to voltage PI regulation state; when BoostDutyState = 1, the state jumps to 0 duty cycle state. Step S903, Voltage PI Adjustment State: When BoostDutyState = 2, the state jumps to the minimum duty cycle state.

[0040] like Figure 12 The flowchart for the 0 duty cycle state is shown below for further explanation: Step S1001, in the 0 duty cycle state; Step S1002: Set the duty cycle of the PWM to a fixed value of 0; Step S1003: Determine whether the reference voltage is more than 15V higher than the charging pile terminal voltage. Here, the reference voltage refers to the voltage value that increases according to the set slope after the MCU receives the voltage request from the VCU, i.e., the voltage after soft start. Step S1004: If the condition is met, BoostPI_State=1, Booststate_TimeCnt=0; The variable BoostPI_State here represents the voltage PI regulation mode, which has three modes: Mode 1: Calculate a fixed duty cycle based on the real-time collected battery pack voltage; Mode 2: Voltage loop PI regulation, calculated once per PWM cycle; Mode 3: During shutdown, the initial duty cycle value is equal to the duty cycle at the end of Mode 2. Where Booststate_TimeCnt is a counter variable; The formula for calculating the duty cycle of Mode 1 is as follows: in Duty cycle, The voltage after a soft start, This refers to the battery terminal bus voltage. K These are calibration coefficients, obtained by calibration on electric vehicles. The calibration coefficients in this invention... K Take 0.8; Step S1005: If the above judgment is not met, continue to judge whether the reference voltage is greater than the charging pile terminal voltage. Step S1006: If the condition is met, Booststate_TimeCnt = 0; Step S1007: If the condition is not met, increment Booststate_TimeCnt by 1; Step S1008: Continue to determine whether Booststate_TimeCnt is greater than 600. If the condition is not met, do not perform any action. Step S1009: The condition is met, BoostDutyState = 2.

[0041] like Figure 13 The flowchart shown further illustrates the minimum duty cycle state: Step S1101, in the minimum duty cycle state; Step S1102: The duty cycle of the PWM is set to a fixed minimum value; Step S1103: Determine whether the reference voltage is greater than the charging pile terminal voltage by more than 15V; Step S1104, the condition is met, BoostDutyState = 1; Step S1105: If the condition is not met, determine whether the reference voltage is greater than the charging pile terminal voltage. Step S1106, the condition is met, ChargeReady_TimeCnt=0; Step S1107: If the condition is not met, increment ChargeReady_TimeCnt by 1; ChargeReady_TimeCnt is a counter variable. Step S1108: Continue to check whether ChargeReady_TimeCnt is greater than 6000. If the condition is not met, do not perform any action. Step S1109, the condition is met, BoostDutyState = 3.

[0042] like Figure 14 The following further illustrates the voltage PI regulation state flowchart: Step S1201, in voltage PI regulation state; In step S1202, this state is entered, where the duty cycle of the PWM changes and is equal to the output value of the PI adjustment in each PWM cycle. Step S1203: Determine whether the reference voltage is greater than 25V or more than the charging pile terminal voltage; Step S1204, the condition is met, BoostDutyState = 2; Step S1205: If the condition is not met, determine whether the reference voltage is greater than the charging pile terminal voltage by more than 15V. Step S1206: If the condition is met, determine whether the current duty cycle is greater than the minimum value; Step S1207, the condition is met, BoostPI_State=3; Step S1208, the condition is not met, BoostPI_State=2; Step S1209: If the condition in step S1205 is not met, increment Booststate_TimeCnt by 1; Step S1210, continue to determine whether Booststate_TimeCnt is greater than 600; Step S1211, the condition is met, BoostPI_State=2; Step S1212: The condition is not met, BoostPI_State=1.

[0043] Example 4 A computer program product includes a computer program that, when executed by a processor, implements the steps of the method described in Embodiment 2.

[0044] Example 5 A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method as described in Embodiment 2.

[0045] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0046] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A system that specifies functions in one or more boxes.

[0047] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including an instruction set implemented in a process. Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0048] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit its scope of protection. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading the present invention, they can still make various changes, modifications or equivalent substitutions to the specific implementation of the invention, but these changes, modifications or equivalent substitutions are all within the scope of protection of the pending claims of the invention.

[0050] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A boost charging software control system that eliminates the motor controller's terminal voltage sampling circuit, characterized in that it include: The voltage information acquisition module is used to periodically acquire the real-time output voltage of the charging pile through the boost distribution box, and send the requested target voltage to the motor controller through the vehicle controller; The state management module is used to manage the running state of the state machine in the boost charging process according to the state machine instructions of the vehicle controller, based on the real-time output voltage and preset state switching conditions, and obtain the current state identifier through the boost charging algorithm. The power control module is used to generate a power transistor control signal based on the real-time output voltage, the target voltage, and the current status indicator through a boost charging algorithm. The power transistor control signal is used to control the operating state of the power transistor in the motor controller, thereby obtaining an adjusted output voltage. The power battery is then boost-charged based on the adjusted output voltage.

2. The boost charging software control system for eliminating the motor controller terminal voltage sampling circuit according to claim 1, characterized in that: The boost charging algorithm adopts a three-phase interleaved parallel control strategy. When the state machine is in the buck state, the three upper bridge power transistors of the motor controller are connected in interleaved parallel through the power transistor control signal, while the three lower bridge power transistors are always turned off.

3. The boost charging software control system for eliminating the motor controller terminal voltage sampling circuit according to claim 1, characterized in that: The boost charging algorithm adopts a three-phase interleaved parallel control strategy. When the state machine is in the boost state, the three lower bridge power transistors of the motor controller are connected in parallel through the power transistor control signal, while the three upper bridge power transistors are always turned off.

4. A boost charging software control system for eliminating the motor controller terminal voltage sampling circuit according to claim 1, characterized in that: The preset state switching conditions include voltage comparison conditions, counter conditions, and fault conditions.

5. A boost charging software control system for eliminating the motor controller terminal voltage sampling circuit according to claim 4, characterized in that: The method for obtaining the current state identifier includes: The vehicle controller sends state machine commands to the motor controller via CAN communication, and manages the operation state of the state machine during the boost charging process based on the real-time output voltage and preset state switching conditions. When charging of an electric vehicle begins, the vehicle controller sends a buck state command to the motor controller via CAN communication. At this time, the state machine is in the buck state. When the vehicle controller determines that it can start boost charging, it sends a boost state command. After the motor controller receives the boost state command, the state machine switches from the buck state to the boost state. Based on the real-time output voltage and preset state switching conditions, the boost charging algorithm determines the state machine's operating state switching according to voltage comparison conditions and counter conditions: When the state machine is in the boost-buck sub-state, it judges the difference between the target voltage requested by the vehicle controller and the real-time output voltage of the charging pile according to the voltage comparison conditions. If the target voltage is less than the real-time output voltage of the charging pile, the counter value is incremented by 1. When the counter value is greater than A, the state machine switches to the boost-wait sub-state; When the state machine is in the boost-boost sub-state, if the target voltage is higher than the real-time output voltage B of the charging pile, the state machine switches to the boost-wait sub-state. The state identifier includes the BoostSubState variable. Different values ​​of the BoostSubState variable correspond to the identifiers of the boost-buck substate, boost-wait substate, and boost-boost substate, respectively, thus obtaining the current state identifier.

6. A boost charging software control system for eliminating the motor controller terminal voltage sampling circuit according to claim 5, characterized in that: The fault condition refers to the state machine immediately jumping to the shutdown state when the motor controller detects a fault. After entering the shutdown state, the motor controller will disable the PWM output of all upper and lower bridge power transistors, putting all power transistors in the shutdown state, and the boost charging process will be forcibly terminated.

7. A boost charging software control system for eliminating the sampling circuit at the pile end of the motor controller according to claim 1, characterized in that: Based on the real-time output voltage, the target voltage, and the current status indicator, a power transistor control signal is generated using a boost charging algorithm. This power transistor control signal is then used to control the operating state of the power transistor in the motor controller, thereby obtaining the adjusted output voltage. The specific process is as follows: The target voltage is subjected to a soft-start process to obtain the voltage after soft start. The current state identifier also includes a BoostDutyState variable. Different values ​​of the BoostDutyState variable correspond to the 0 duty cycle state, minimum duty cycle state, and voltage PI adjustment state in the power transistor control signal, respectively. Based on the real-time output voltage, the target voltage, and the current state identifier, a PWM duty cycle signal is generated using a boost charging algorithm. The duty cycle in the 0 duty cycle state is fixed at 0; The duty cycle in the minimum duty cycle state is set to a fixed minimum value, and the formula is: in, This represents the maximum duty cycle corresponding to the PWM period. This represents the minimum duty cycle value. Voltage PI regulation states include fixed duty cycle and PI-regulated duty cycle: The formula for calculating a fixed duty cycle is: in, To maintain a fixed duty cycle, The voltage after a soft start, This refers to the battery terminal bus voltage. K These are calibration coefficients; The duty cycle of the PI regulator is controlled in a closed loop by the PI regulator. The target voltage is compared with the real-time output voltage to obtain the error, and the PI regulator is automatically adjusted according to the error. By determining whether the state machine is in buck or boost state, it is determined whether the three upper-bridge power transistors or the three lower-bridge power transistors will operate. Then, the PWM duty cycle signal determines the conduction strength of the power transistors: for a 0 duty cycle, the power transistors are completely off; for a minimum duty cycle, the power transistors operate at low power; for voltage PI regulation, with a fixed duty cycle, the power transistors operate at a preset power; with PI regulation, the power transistors operate according to the duty cycle dynamically calculated by the PI regulator, thus obtaining the adjusted output voltage.

8. A boost charging software control method that eliminates the need for a motor controller terminal voltage sampling circuit, characterized in that, It includes the following steps: The real-time output voltage of the charging pile is periodically obtained through the boost distribution box, and the target voltage is requested by the vehicle controller to the motor controller. According to the state machine instructions of the vehicle controller, based on the real-time output voltage and preset state switching conditions, the running state of the state machine in the boost charging process is managed by the boost charging algorithm to obtain the current state identifier; Based on the real-time output voltage, the target voltage, and the current status indicator, a power transistor control signal is generated through a boost charging algorithm. The power transistor control signal controls the operating state of the power transistor in the motor controller, thereby obtaining the adjusted output voltage. The power battery is then boost-charged based on the adjusted output voltage.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method of claim 8.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, it implements the steps of the method as described in claim 8.

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