Vehicle-mounted charging and discharging system based on DSP + FPGA control

Abstract

The invention discloses a vehicle-mounted charging and discharging system based on DSP + FPGA control, and relates to the technical field of charging and discharging control, the system is composed of an AC / DC unit, a battery unit, a DC / DC unit, charging and discharging control and an AC / DC charging gun, a DSP + FPGA control architecture is adopted, the performance and reliability of the vehicle-mounted charging and discharging system are greatly optimized, and the charging and discharging efficiency is improved. The powerful computing power of the DSP can optimize the charging and discharging strategy in real time according to the battery state and the requirements of external equipment, safe and efficient charging and discharging of the battery are ensured, the service life of the battery is prolonged, the PWM pulse logic protection realized by the FPGA effectively prevents the power device from being damaged, and the service life of the battery is prolonged. The analog acquisition and multi-path input / output extended function enhances the processing and interaction capability of the system to various signals, and the analog acquisition and multi-path input / output extended function and the multi-path input / output extended function work cooperatively, so that the system can quickly and accurately deal with various working condition changes, the stability and accuracy of the charging and discharging process are improved, and the system fault risk is reduced. And a powerful guarantee is provided for long-term stable operation of the vehicle-mounted charging and discharging system.

Description

Technical Field

[0001] The present invention relates to the technical field of charge and discharge control, and in particular to a vehicle-mounted charge and discharge system based on DSP+FPGA control. Background Art

[0002] With the global emphasis on environmental protection and sustainable energy development, new energy vehicles are an important solution to reduce carbon emissions and dependence on traditional fuels. The on-board charging and discharging system, as a key component of new energy vehicles, not only affects the charging efficiency and endurance of the vehicle, but also plays an important role in the energy interaction between the vehicle and external equipment. At the same time, with the continuous advancement of electronic technology, digital signal processing (DSP) and field programmable gate array (FPGA) technologies have shown strong advantages in the field of industrial control, providing a technical foundation for the innovation of on-board charging and discharging systems.

[0003] However, existing on-vehicle charging and discharging systems have obvious deficiencies in logic protection and control. They use simple control circuits or general microcontrollers with limited processing capabilities, making it difficult to cope with complex and changeable charging and discharging conditions. During the charging process, the charging current and voltage cannot be accurately adjusted according to the battery status, which can easily lead to overcharging or undercharging of the battery, affecting the battery life. For the discharge process, there is a lack of intelligent recognition and dynamic response capabilities to external device requirements, and it is impossible to perform efficient power conversion and supply according to the actual power requirements of the equipment. Summary of the invention

[0004] The purpose of the present invention is to make up for the shortcomings of the prior art and provide a vehicle-mounted charging and discharging system based on DSP+FPGA control. The system adopts the DSP+FPGA control method to significantly simplify the limitations of traditional DSP+peripheral circuits to achieve complex control, and realizes the logical protection of PWM pulses and the expansion of multi-channel input and output signals. This combination not only simplifies the system architecture and reduces hardware costs, but also significantly improves the stability and reliability of the system.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: an on-vehicle charging and discharging system based on DSP+FPGA control, the system is composed of an AC / DC unit, a battery unit, a DC / DC unit, a charging and discharging control and an AC / DC charging gun;

[0006] The AC / DC unit includes a filter, an IGBT module and a three-level module, which converts AC power into DC power to provide the power required for charging the battery unit, wherein:

[0007] The filter uses an electromagnetic interference filter to filter out the input high-frequency clutter, spike pulses and low-frequency interference signals;

[0008] The IGBT module uses an insulated gate bipolar transistor module. Under the drive of the control signal, it controls the conduction and shutdown of the AC power, converts the input AC power into a high-frequency pulse signal, and provides an input waveform for the three-level module.

[0009] The three-level module is composed of multiple power semiconductor devices and capacitors. It rectifies and stabilizes the high-frequency pulse signal output by the IGBT module, converts it into a stable DC voltage and outputs it to the power conversion circuit. It adjusts the DC BUS+ / BUS- voltage by precisely controlling the on and off timing of the power semiconductor devices.

[0010] The battery unit adopts a battery management system BMS to comprehensively manage and monitor the battery pack. Through multiple temperature sensors, voltage sensors and current sensors distributed in the battery pack, the temperature, voltage and current parameters of the battery are collected in real time to evaluate the battery status, including the remaining power SOC and health status SOH of the battery;

[0011] The DC / DC unit is composed of a power conversion and control circuit, which converts the DC power output by the battery unit into DC power and AC power suitable for charging external devices, wherein:

[0012] The power switch device in the power conversion circuit converts the DC power output by the battery unit into a voltage according to the charging requirements of the external device;

[0013] The control circuit receives the control signal sent by the charge and discharge control, and generates a pulse width modulation PWM signal to drive the power switch device according to the signal. The control circuit adopts a closed-loop control algorithm to monitor the output voltage and current in real time and compare them with the reference value. By adjusting the duty cycle of the PWM signal, the output voltage and current are stabilized;

[0014] The charge and discharge control adopts DSP+FPGA architecture to accurately control the AC / DC unit and DC / DC unit;

[0015] The DSP calculates the optimal charging current and voltage curves according to the battery status information provided by the battery management system BMS, namely, SOC, SOH, and temperature, and monitors the working status of the AC / DC unit and the DC / DC unit in real time, and judges the system fault status by comparing with the fault threshold. At the same time, the DSP is responsible for communicating with external devices, receiving charging requests and control instructions from external devices, and feeding back system status information to external devices;

[0016] The FPGA performs logic protection on the PWM pulses in the DC / DC unit, and collects the parameters of current, voltage, and temperature in the discharge process in real time through analog acquisition, converts them into digital signals and transmits them to the DSP for analysis and processing;

[0017] The AC / DC charging gun is equipped with AC and DC charging interfaces, which can be compatible with the charging requirements of external devices of different standards, and transmit information to the charging and discharging control to automatically match the optimal charging mode and parameters.

[0018] Furthermore, the battery cell is provided with a plurality of temperature sensors T1, T2, ..., T n , where n is the number of temperature sensors, T i represents the temperature value collected by the i-th temperature sensor, the voltage sensor V1, V2, ..., V m , where m is the number of voltage sensors, V j represents the voltage value collected by the jth voltage sensor, the current sensor I1, I2, ..., I k , where k is the number of current sensors, I l It represents the current value collected by the lth current sensor, collects the temperature, voltage and current parameters of the battery in real time, and calculates the remaining capacity SOC of the BMS battery as: Where Q r is the remaining capacity of the battery, Q n is the rated capacity of the battery, and the remaining capacity of the battery is Q r The calculation is based on the discharge characteristic curve of the battery, by calculating the current voltage of the battery and current Integrate to get Where t is the discharge time.

[0019] Furthermore, the battery health state SOH of the BMS in the battery unit is: Where Q max is the maximum available capacity of the battery, i.e. Q max =fT average , N, where T average is the average temperature of the battery during use and N is the number of charge and discharge cycles of the battery. At the same time, the BMS transmits the calculated SOC, SOH, and battery temperature, voltage, and current parameters to the DSP in the charge and discharge control in real time.

[0020] Furthermore, the power conversion circuit in the DC / DC unit converts the DC power output by the battery unit into a voltage, that is, the output voltage of the battery unit is V in , the power switch conduction time is t on , the off time is t off , switching period T = t on +t off ,in:

[0021] For the step-down circuit, the output voltage Vout for:

[0022] For the boost circuit, the output voltage V out for:

[0023] For the buck-boost circuit, the output voltage V out for: Through the turn-on and turn-off time t on and t off , to achieve the output voltage V out Precise adjustment to meet the charging voltage requirements of different external devices.

[0024] Furthermore, the control circuit in the DC / DC unit receives a control signal sent by the charge and discharge control, and the control signal includes a target output voltage V set according to the charging requirements of the external device and the state of the battery unit. target and the target output current I target The control circuit uses a closed-loop control algorithm to monitor the output voltage V of the power conversion circuit in real time. out and output current I out , that is, the voltage error e V =V target -V out , current error e I =I t arget-I out According to the error value, the duty cycle D of the PWM signal is calculated by the proportional integral controller. For the voltage controller, its output is Where K pV is the voltage proportionality coefficient, K iV is the voltage integral coefficient; for the current controller, its output Where K p I is the current proportionality coefficient, K i I is the current integral coefficient, and its PWM signal duty cycle D is determined by the control results of the voltage loop and the current loop as D = f(u V ,u I ).

[0025] Furthermore, in the charge and discharge control, the DSP is based on the battery status information provided by the BMS, namely the remaining power SOC, health status SOH, temperature T battery , calculate the optimal charging current I charge and voltage V charge Curve, for charging current I charge The calculation takes into account the current SOC value and temperature T of the battery battery , using piecewise function form, that is: Among them, I1, I2, ..., In is the charging current value corresponding to different SOC intervals, SOC1, SOC2, ..., SOC n-1 It is the SOC segmentation point.

[0026] Furthermore, when the DC / DC unit is working, the FPGA performs logic protection on the PWM pulse, that is, the original duty cycle of the PWM signal is D0, and the dead time t is added. dead , the duty cycle of the PWM signal after dead zone processing is D protected Adjust according to the dead time and switching period T, that is

[0027] Furthermore, the charge and discharge control FPGA is connected to an external analog signal conditioning circuit to adjust the current I during the discharge process. discharge , voltage V discharge , Temperature T system The analog signal is collected and converted into a digital signal with a resolution of N bits and a reference voltage of V ref ,in:

[0028] For current acquisition, the analog voltage output by the current sensor is V I , then the converted digital current value is Among them I max is the maximum current value measured by the current sensor, V max is the maximum value of the output voltage of the current sensor;

[0029] For voltage acquisition, the analog voltage output by the voltage sensor is V V , then the converted digital voltage value is Where V max The maximum voltage value measured by the voltage sensor;

[0030] For temperature acquisition, the analog voltage output by the temperature sensor is V T , then the converted digital temperature value is Where T max The highest temperature value measured by the temperature sensor.

[0031] Compared with the existing technology, the vehicle-mounted charging and discharging system based on DSP+FPGA control has the following beneficial effects:

[0032] 1. The present invention adopts DSP+FPGA control architecture, which greatly optimizes the performance and reliability of the vehicle-mounted charging and discharging system. The powerful computing power of DSP can optimize the charging and discharging strategy in real time according to the battery status and external equipment requirements, ensure safe and efficient charging and discharging of the battery, and extend the battery life. The PWM pulse logic protection implemented by FPGA effectively prevents damage to power devices. The analog acquisition and multi-channel input / output expansion functions enhance the system's processing and interaction capabilities for various signals. The two work together to enable the system to respond quickly and accurately to various operating conditions, improve the stability and accuracy of the charging and discharging process, reduce the risk of system failure, and provide strong guarantees for the long-term stable operation of the vehicle-mounted charging and discharging system.

[0033] 2. The vehicle-mounted charging and discharging system of the present invention, which is based on DSP+FPGA control, greatly optimizes the charging and discharging performance and system stability. During charging, the current and voltage curves are accurately adjusted according to the battery status information to avoid overcharging and over-discharging, effectively extending the battery life.

[0034] Other advantages, objectives and features of the present invention will be set forth in part in the following description and, in part, will be apparent to those skilled in the art based on an examination of the following or may be taught from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 This is a structural connection diagram of a vehicle-mounted charging and discharging system based on DSP+FPGA control;

[0037] Figure 2 This is a flow chart of a vehicle charging and discharging system based on DSP+FPGA control. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Embodiment 1

[0040] This embodiment describes in detail the specific application of a vehicle-mounted charging and discharging system based on DSP+FPGA control in the discharge process. The vehicle moves to the external device and uses an AC / DC charging gun to connect to the external device to charge the external device. In this process, the various components of the system work together, fully demonstrating its high efficiency, stability and intelligence. In particular, it highlights the key role of DSP and FPGA in control, protection and data processing.

[0041] In the specific implementation process, the system includes (1) AC / DC unit, (2) battery unit, (3) DC / DC unit, (4) charging and discharging control system, and (5) AC / DC charging gun. Figure 1 As shown, the AC / DC unit (1) comprises a filter and an IGBT module; one end of the filter is connected to an AC / DC charging gun (5) and the other end is connected to a three-level module; the DC BUS+ / BUS- of the three-level module is connected to a battery unit (2); the battery unit (2) is connected to a DC / DC unit (3); the DC / DC unit (3) is connected to an AC / DC charging gun (5); a charge and discharge control system (4) is simultaneously connected to the battery unit (2), the AC / DC unit (1) and the DC / DC unit (3); the charge and discharge control system (4) is a DSP+FPGA control unit that controls the charging of the battery unit (2) through the AC / DC unit (1) and the discharging of the battery unit (2) through the DC / DC unit (3) through PWM pulse logic protection, analog acquisition and multi-channel input / output expansion, thereby preventing the battery unit (2) from being overcharged or over-discharged, thereby protecting the battery and increasing the battery life.

[0042] When the battery management system BMS in the battery unit is distributed in the battery pack through multiple temperature sensors (T1, T2, ..., T n ), voltage sensors (V1, V2, ..., V m ) and current sensors (I1, I2, ..., I k ) After real-time acquisition of battery parameters, when it is detected that the battery power is lower than the charging threshold, the charging start signal is triggered, and a charging request signal is immediately sent to the charge and discharge control system. The signal contains the current status information of the battery, such as the remaining power (SOC), health state (SOH) and battery temperature and other key parameters. The calculation method of the battery remaining power SOC is Q r is the remaining capacity of the battery, Q n is the rated capacity of the battery, (t is the discharge time, is the current current value, which is calculated from the values ​​collected by multiple current sensors), and the battery health status SOH is calculated as Q maxis the current maximum available capacity of the battery, i.e. Q max =f(T average , N)( is the average temperature of the battery during use, and N is the number of battery charge and discharge cycles). After the charge and discharge control receives the request signal, the AC / DC unit is started, and the filter in the AC / DC unit begins to filter the AC power from the AC / DC charging gun. The filter uses an electromagnetic interference filter. The filter network composed of multiple layers of inductors and capacitors inside can effectively filter out high-frequency clutter, spike pulses and low-frequency interference signals input from the mains, ensuring that the power input to the subsequent circuit is pure and stable. The filtered AC power enters the IGBT module. The IGBT module uses an insulated gate bipolar transistor module. Under the drive of the control signal, the AC power is converted into a high-frequency pulse signal. The temperature sensor and overcurrent protection circuit integrated in the IGBT module monitor its own operating temperature in real time (set as T IGBT ) and the current magnitude (set to I ACDC ), when T IGBT Exceeds the preset upper temperature limit T IGBT max or I ACDC Exceeds the preset overcurrent threshold I ACDCmax When the fault signal is sent to the charge and discharge control system immediately to ensure system safety, the high-frequency pulse signal output by the IGBT module then enters the three-level module, which is composed of multiple power semiconductor devices and capacitors. By accurately controlling the on and off timing of the power semiconductor devices, the high-frequency pulse signal is rectified and stabilized, and converted into a stable DC voltage output to the battery unit. Suppose the output voltage of the battery unit is V in , the conduction time of the power switch device (MOSFET tube) is t on , the off time is t off , switching period T = t on +t off , the DC voltage V output by the three-level module DCout1 (i.e. the voltage at which the battery cell is charged).

[0043] After receiving the battery status information from the BMS, the DSP in the charge and discharge control system calculates the battery status according to the battery SOC value and temperature T battery , calculate the optimal charging current I charge and voltage V charge Curve, charging current I charge In piecewise function form: where I1, I2, …, I n is the charging current value corresponding to different SOC intervals, SOC1, SOC2, ..., SOC n-1 are 50C segmentation points. These values ​​are determined based on the battery charging characteristic curve and safe charging requirements.charge =I charge (SOC, T battery ), that is, the charging current is affected by SOC and temperature, and the charging voltage V charge Also with SOC and T battery It is related to the calculation through piecewise function, that is, V charge =V charge (SOC, T battery ), FPGA performs logic protection on the PWM pulse of the AC / DC unit during the charging process. Assuming the original duty cycle of the PWM signal is D0, FPGA will add a dead time t to prevent the power switch device from being directly connected during the on and off process. dead . Duty cycle of PWM signal after dead zone processing Ensure safe and reliable operation of power devices.

[0044] Finally, as the charging process proceeds, the BMS continuously monitors the battery status. When the battery reaches the full charge threshold, the BMS sends a signal to the charge and discharge control system again to notify that charging is complete. After receiving the signal, the charge and discharge control system stops the AC / DC unit and activates the battery protection mechanism, such as cutting off the charging circuit to prevent the battery from overcharging. At the same time, the BMS continues to monitor the battery status in real time to maintain the battery in a suitable state for subsequent use.

[0045] In summary, this embodiment shows in detail the complete process of the vehicle-mounted charging and discharging system during the charging process. The various parts work closely together to achieve an efficient, safe and stable charging process, which fully reflects the advantages of the vehicle-mounted charging and discharging system based on DSP+FPGA control in the charging function of the present invention.

[0046] Embodiment 2

[0047] This embodiment describes in detail the discharge process of the vehicle-mounted charging and discharging system based on DSP+FPGA control to the external device, including the precise control of the DC / DC unit and the application of the intelligent management of the charging and discharging control system in the discharge scenario, which reflects the efficiency and reliability of the system in the discharge function.

[0048] In the specific implementation process, when the vehicle moves near an external device that needs to be charged, the AC / DC charging gun is inserted into the charging port of the external device, and the intelligent recognition circuit inside the charging gun automatically detects the charging type of the external device (C type , divided into AC or DC), charging power demand (P request) and other information, the charging gun is closely connected with the external device through its electrical interface to ensure the stability of power transmission. At the same time, the charging gun has functions such as overvoltage protection, overcurrent protection and leakage protection. During the connection process, once abnormal electrical parameters are detected, the charging circuit is immediately cut off to protect the safety of external devices and the vehicle-mounted charging and discharging system. The charging gun transmits the detected external device information to the charging and discharging control system, and the charging and discharging control system begins to prepare for the discharge operation based on this information.

[0049] First, after receiving information from external devices, the charge and discharge control system obtains the remaining power (SOC), health status (SOH) and battery temperature T of the battery cell. battery And other information, among which, is the remaining capacity of the battery, Q n is the rated capacity of the battery, is the current value, and the calculation of SOH is: (Q max It is related to the cycle life of the battery and the ambient temperature of the environment, that is, Q max =f(T average , N), is the average temperature of the battery during use, and N is the number of battery charge and discharge cycles). According to the state of the battery cell and the charging requirements of the external device, the charge and discharge control system determines whether the discharge conditions are met. If the conditions are met, the system starts the DC / DC unit and prepares to convert the DC power of the battery cell into an electric energy form suitable for charging the external device. The power conversion circuit in the DC / DC unit converts the DC power output by the battery cell into a voltage according to the control signal sent by the charge and discharge control system. Suppose the output voltage of the battery cell is V in , the conduction time of the power switch device (MOSFET tube) is t on , the off time is t off , switching period T = t o n+t off , for the step-down circuit, the output voltage V out (i.e. the voltage used to charge external devices) is calculated as By precisely controlling t on and T values, the output voltage can be precisely adjusted to meet the charging voltage requirements of different external devices; for the boost circuit, the output voltage By adjusting t on and T, which can increase the voltage of the battery cell to the voltage level required by the external device; for the buck-boost circuit, the output voltage The on and off time of the power switch device is flexibly controlled according to the voltage requirements of the external device. At the same time, the power conversion circuit monitors the output current I in real time. out, assuming the load resistance is R L , according to Ohm's law After the output voltage is determined, when I out Exceeds the preset current upper limit I outmax The on and off time of the MOSFET tube will be adjusted to limit the output current and prevent overcurrent from damaging external devices or the system itself. The control circuit receives instructions from the charge and discharge control system and uses a closed-loop control algorithm to monitor the output voltage V of the power conversion circuit in real time. out and output current I out , assuming the voltage error e V =V target -V out , current error e I =I target -I out (I target is the target output current); for the voltage loop PI controller, its output (K pV is the voltage proportionality coefficient, K iV is the voltage integral coefficient), which is used to adjust the duty cycle of the PWM signal so that the output voltage is stable near the target value. For the current loop PI controller, its output (K pI is the current proportionality coefficient, K iI is the current integral coefficient), which also affects the determination of the PWM signal duty cycle. The final PWM signal duty cycle D is determined based on the control results of the voltage loop and the current loop, that is, D = f(u V ,u I ), generates a pulse width modulation (PWM) signal to drive the power switch device (MOSFET tube) according to the duty cycle, so that the output voltage and current are stable within the required range. out Exceeds the preset overvoltage threshold V ov When the output current I out Exceeds the preset overcurrent threshold I oc At the same time, the PWM signal output is also stopped to protect the system from excessive current shock. At the same time, the control circuit also has a soft start function. When the system starts, the duty cycle of the PWM signal is gradually increased to make the output voltage and current rise slowly to avoid instantaneous shock to external devices and system components.

[0050] Then, the DSP continuously monitors the status of the battery cell during the discharge process, including the remaining power SOC, temperature T batteryAccording to the battery status information, the battery is ensured not to be over-discharged. At the same time, according to the change of the charging status of the external device, when the power required by the external device during the charging process changes, the DSP will recalculate the target output voltage V target and the target output current I target , and sends the new control signal to the control circuit of the DC / DC unit to adjust its output parameters. The FPGA performs logical protection on the PWM pulse in the DC / DC unit, that is, the original duty cycle of the PWM signal is D0. To prevent the power switch device from being directly connected during the on and off process, the FPGA will add a dead time t dead , the duty cycle of the PWM signal after dead zone processing At the same time, FPGA collects the current I in the discharge process in real time through the analog acquisition module disch arge , voltage V disch arge , Temperature T system (including the internal temperature of the DC / DC unit, the temperature of the battery unit and other key temperature points of the system) and other parameters. Assume that the resolution of the analog signal conditioning circuit to convert the analog signal into a digital signal is N bits (for example, N = 12 bits), and the reference voltage is V ref For current acquisition, if the analog voltage output by the current sensor is V I , then the converted digital current value (I max is the maximum current value measured by the current sensor, V max For voltage acquisition, if the analog voltage output by the voltage sensor is V V , then the converted digital voltage value (V m ax is the maximum voltage value measured by the voltage sensor). For temperature acquisition, if the analog voltage output by the temperature sensor is V T , then the converted digital temperature value (T max The FPGA packages the collected digital current, voltage, temperature and other parameters in a data format and transmits them to the DSP through the data bus for analysis and processing. The DSP further optimizes the control strategy based on these real-time parameters to ensure that the safety of the battery unit is protected while meeting the charging needs of external devices.

[0051] Finally, when the external device is fully charged or the battery cell power level is lower than the discharge termination threshold, the charge and discharge control system stops the DC / DC unit, ends the discharge process, and the system returns to standby mode, waiting for the next charge and discharge task. After the discharge is completed, the BMS continues to monitor and manage the battery cell to maintain the battery in good condition.

[0052] To sum up, this embodiment comprehensively demonstrates the discharge process of the on-board charging and discharging system for external devices, starting from device connection and demand identification, to complex power conversion and precise control of the DC / DC unit, to intelligent monitoring and adjustment of the charging and discharging control system, and finally system state recovery after the discharge is completed. Each link works closely together to achieve efficient, stable and safe discharge function according to the needs of external devices, reflecting the flexibility and reliability of the on-board charging and discharging system of the present invention in responding to the charging needs of different external devices, as well as the advantages of the coordinated work of various components to ensure the overall performance of the system.

[0053] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A vehicle-mounted charging and discharging system based on DSP+FPGA control, characterized in that: The system consists of an AC / DC unit, a battery unit, a DC / DC unit, a charge and discharge control, and an AC / DC charging gun; The AC / DC unit includes a filter, an IGBT module and a three-level module, which converts AC power into DC power to provide the power required for charging the battery unit, wherein: The filter uses an electromagnetic interference filter to filter out the input high-frequency clutter, spike pulses and low-frequency interference signals; The IGBT module uses an insulated gate bipolar transistor module. Under the drive of the control signal, it controls the conduction and shutdown of the AC power, converts the input AC power into a high-frequency pulse signal, and provides an input waveform for the three-level module. The three-level module is composed of multiple power semiconductor devices and capacitors. It rectifies and stabilizes the high-frequency pulse signal output by the IGBT module, converts it into a stable DC voltage and outputs it to the power conversion circuit. It adjusts the DC BUS+ / BUS- voltage by precisely controlling the on and off timing of the power semiconductor devices. The battery unit adopts a battery management system BMS to comprehensively manage and monitor the battery pack. Through multiple temperature sensors, voltage sensors and current sensors distributed in the battery pack, the temperature, voltage and current parameters of the battery are collected in real time to evaluate the battery status, including the remaining power SOC and health status SOH of the battery; The DC / DC unit is composed of a power conversion and control circuit, which converts the DC power output by the battery unit into DC power and AC power suitable for charging external devices, wherein: The power switch device in the power conversion circuit converts the DC power output by the battery unit into a voltage according to the charging requirements of the external device; The control circuit receives the control signal sent by the charge and discharge control, and generates a pulse width modulation PWM signal to drive the power switch device according to the signal. The control circuit adopts a closed-loop control algorithm to monitor the output voltage and current in real time and compare them with the reference value. By adjusting the duty cycle of the PWM signal, the output voltage and current are stabilized; The charge and discharge control adopts DSP+FPGA architecture to accurately control the AC / DC unit and DC / DC unit; The DSP calculates the optimal charging current and voltage curves according to the battery status information provided by the battery management system BMS, namely, SOC, SOH, and temperature, and monitors the working status of the AC / DC unit and the DC / DC unit in real time, and judges the system fault status by comparing with the fault threshold. At the same time, the DSP is responsible for communicating with external devices, receiving charging requests and control instructions from external devices, and feeding back system status information to external devices; The FPGA performs logic protection on the PWM pulses in the DC / DC unit, and collects the parameters of current, voltage, and temperature in the discharge process in real time through analog acquisition, converts them into digital signals and transmits them to the DSP for analysis and processing; The AC / DC charging gun is equipped with AC and DC charging interfaces, which can be compatible with the charging requirements of external devices of different standards, and transmit information to the charging and discharging control to automatically match the optimal charging mode and parameters.

2. According to the DSP+FPGA controlled vehicle-mounted charging and discharging system of claim 1, it is characterized in that: The battery cell is connected to the battery pack through a plurality of temperature sensors T1, T2, ..., T n , where n is the number of temperature sensors, T i represents the temperature value collected by the i-th temperature sensor, the voltage sensor V1, V2, ..., V m , where m is the number of voltage sensors, V j represents the voltage value collected by the jth voltage sensor, the current sensor I1, I2, ..., I k , where k is the number of current sensors, I l It represents the current value collected by the lth current sensor, collects the temperature, voltage and current parameters of the battery in real time, and calculates the remaining capacity SOC of the BMS battery as: Where Q r is the remaining capacity of the battery, Q n is the rated capacity of the battery, and the remaining capacity of the battery is Q r The calculation is based on the discharge characteristic curve of the battery, by calculating the current voltage of the battery and current Integrate to get Where t is the discharge time.

3. The vehicle-mounted charging and discharging system based on DSP+FPGA control according to claim 1 is characterized in that: The battery health state SOH of the BMS in the battery cell is: Where Q max is the maximum available capacity of the battery, i.e. Q max =f(T average ,N), where T average is the average temperature of the battery during use and N is the number of charge and discharge cycles of the battery. At the same time, the BMS transmits the calculated SOC, SOH, and battery temperature, voltage, and current parameters to the DSP in the charge and discharge control in real time.

4. The vehicle-mounted charging and discharging system based on DSP+FPGA control according to claim 1 is characterized in that: The power conversion circuit in the DC / DC unit converts the DC power output by the battery unit into a voltage, that is, the output voltage of the battery unit is V in , the power switch conduction time is t on , the off time is t off , switching period T = t on +t off ,in: For the step-down circuit, the output voltage V out for: For a boost circuit, the output voltage V out for: For the buck-boost circuit, the output voltage V out for: Through the turn-on and turn-off time t on and t off , to achieve the output voltage V out Precise adjustment to meet the charging voltage requirements of different external devices.

5. The vehicle-mounted charging and discharging system based on DSP+FPGA control according to claim 1 is characterized in that: The control circuit in the DC / DC unit receives a control signal sent by the charge and discharge control, and the control signal includes a target output voltage V set according to the charging requirements of the external device and the battery unit status. target and the target output current I target The control circuit uses a closed-loop control algorithm to monitor the output voltage V of the power conversion circuit in real time. out and output current I out , that is, the voltage error e V =V target -V out , current error e I =I t arget-I out According to the error value, the duty cycle D of the PWM signal is calculated by the proportional-integral controller. For the voltage controller, its output is Where K pV is the voltage proportionality coefficient, K iV is the voltage integral coefficient; for the current controller, its output Where K p I is the current proportionality coefficient, K i I is the current integral coefficient, and its PWM signal duty cycle D is determined by the control results of the voltage loop and the current loop as D = f(u V ,u I ).

6. The vehicle-mounted charging and discharging system based on DSP+FPGA control according to claim 1 is characterized in that: In the charge and discharge control, DSP uses the battery status information provided by BMS, namely the remaining power SOC, health status SOH, temperature T battery , calculate the optimal charging current I charge and voltage V charge Curve, for charging current I charge The calculation takes into account the current SOC value and temperature T of the battery battery , using piecewise function form, that is: Among them, I1, I2, …, I n is the charging current value corresponding to different SOC intervals, SOC1, SOC2,…, SOC n-1 It is the SOC segmentation point.

7. The vehicle-mounted charging and discharging system based on DSP+FPGA control according to claim 1 is characterized in that: When the FPGA is working in the DC / DC unit, the PWM pulse is logically protected, that is, the original duty cycle of the PWM signal is D0, and the dead time t is added. dead , the duty cycle of the PWM signal after dead zone processing is D protected Adjust according to the dead time and switching period T, that is 8. The vehicle-mounted charging and discharging system based on DSP+FPGA control according to claim 1 is characterized in that: The charge and discharge control FPGA is connected to an external analog signal conditioning circuit to adjust the current I during the discharge process. discharge , voltage V discharge , Temperature T system The analog signal is collected and converted into a digital signal with a resolution of N bits and a reference voltage of V ref ,in: For current acquisition, the analog voltage output by the current sensor is V I , then the converted digital current value is Among them I max is the maximum current value measured by the current sensor, V max is the maximum value of the output voltage of the current sensor; For voltage acquisition, the analog voltage output by the voltage sensor is V V , then the converted digital voltage value is Where V max The maximum voltage value measured by the voltage sensor; For temperature acquisition, the analog voltage output by the temperature sensor is V T , then the converted digital temperature value is Where T max The highest temperature value measured by the temperature sensor.

Images