DC conversion system

Abstract

The invention relates to the field of direct-current conversion digital control. The embodiment of the invention provides a direct current conversion system, which comprises a main power module for realizing power conversion and a digital control module, wherein the digital control module is realized through a dual-core single chip, a first processing core of the dual-core single chip is used for controlling the main power module, and a second processing core of the dual-core single chip is used for carrying out system-level monitoring management on the DC conversion system. A digital control module of a direct current conversion system is realized by using a dual-core single chip, multiple functions are realized by using only one chip, the complexity of system circuit design is reduced, the energy density is improved, the hardware design period is shortened, a multi-task cooperation mode among a plurality of chips does not need to be considered, and the cost is reduced. In addition, the number of chips is reduced, so that the energy loss of the main control chip is reduced, the integration degree of the system is improved, and the real-time performance of communication is improved.

Description

[0001] This application is a divisional application with application number 202011035533.5. The application date of the parent application is September 27, 2020. The name of the invention of the parent application is: DC conversion system. Technical Field

[0002] The invention relates to the field of direct current conversion digital control, and in particular to a direct current conversion system. Background Art

[0003] With the widespread use of DC voltage-powered loads, DC conversion systems have been increasingly widely used. The digital control part of complex DC-DC conversion systems is limited by input and output port resources and the speed of the processor when running multiple tasks, and both use dual chips to implement control functions. The DC conversion system using dual chips decouples the converter monitoring function, process control function, memory, and interrupt tasks, and controls them separately by corresponding chips.

[0004] However, the inventors have discovered that the related technology has the following problems: In the related technology, the hardware circuit design of the dual-chip system architecture is complex, resulting in a long R&D cycle. When designing software, the coordination and cooperation between multiple tasks is complex. In addition, the dual chips have high power consumption, and the real-time communication between the dual chips is poor. Summary of the invention

[0005] The main purpose of the embodiment of the present application is to provide a DC conversion system, which adopts a dual-core single-chip microcontroller unit, which can reduce the complexity of the system hardware circuit, thereby shortening the research and development cycle, simplifying the coordination and cooperation between multiple tasks, reducing power consumption, and enhancing the real-time performance of communication among various tasks.

[0006] To solve the above problems, an embodiment of the present invention provides a DC conversion system, comprising: a main power module for realizing power conversion, and a digital control module; wherein the digital control module is implemented by a dual-core single chip, the first processing core of the dual-core single chip is used to control the main power module, and the second processing core of the dual-core single chip is used to perform system-level monitoring and management of the DC conversion system.

[0007] Compared with the related art, the embodiments of the present invention use a dual-core single chip to implement the digital control module of the DC conversion system, and realize multiple functions with only one chip, which reduces the complexity of the system's circuit design, improves the energy density, shortens the hardware design cycle, and does not need to consider the coordinated cooperation mode of multiple tasks between multiple chips, thereby simplifying the coordinated cooperation mode between multiple tasks. In addition, the number of chips is reduced, and the dual cores in a chip work alternately to achieve controllable sleep, which reduces the energy loss of the main control chip and increases the degree of system integration. Moreover, during communication, only the communication between the dual cores needs to be considered, and the dual cores are in the same chip, thereby improving the real-time performance of communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a system block diagram of a DC conversion system in a first embodiment;

[0009] Figure 2 is a system architecture diagram of a DC-DC direct current conversion system in a first embodiment;

[0010] Figure 3 is a system block diagram of a unidirectional DC-DC conversion system in a first embodiment;

[0011] Figure 4 is a full-bridge LLC topology diagram of a unidirectional DC-DC unit in the first embodiment;

[0012] Figure 5 This is a functional analysis diagram of a one-way DCDC system in the first embodiment;

[0013] Figure 6 This is a diagram of the chip functions and resource allocation of the unidirectional DCDC system in the first embodiment;

[0014] Figure 7 is a schematic diagram of the relationship between the peripheral hardware circuit unit and the dual-core MCU of the unidirectional DCDC system in the first embodiment;

[0015] Figure 8 is a system block diagram of a bidirectional DC conversion system based on multiple interleaved bidirectional DC-DC units in a second embodiment;

[0016] Fig. 9 is a topological diagram of multiple interleaved parallel H-bridges in the second embodiment;

[0017] Fig.10 is a topological diagram of multiple dual active bridges in the second embodiment;

[0018] Fig.11 is a bidirectional unit control task diagram of a bidirectional DC conversion system based on multiple interleaved bidirectional DC-DC units in a second embodiment;

[0019] Fig.12is a system monitoring task diagram of a bidirectional DC conversion system based on multiple interleaved bidirectional DC-DC units in a second embodiment;

[0020] Fig.13 is a block diagram of task allocation and resource allocation of a bidirectional DC conversion system based on multiple interleaved bidirectional DC-DC units in a second embodiment;

[0021] Fig.14 is a schematic diagram of the connection between the dual-core MCU and the external hardware circuit unit of the bidirectional DC conversion system based on multiple interleaved bidirectional DC-DC units in the second embodiment;

[0022] Fig.15 is a system block diagram of a bidirectional DC conversion system based on a bidirectional DC-DC unit in a second embodiment;

[0023] Fig.16 is a system function analysis diagram of a bidirectional DC conversion system based on a bidirectional DC-DC unit in the second embodiment;

[0024] Fig.17 is a system chip function and resource allocation diagram of a bidirectional DC conversion system based on a bidirectional DC-DC unit in a second embodiment;

[0025] Fig.18 is a schematic diagram of the relationship between the peripheral hardware circuit unit and the dual-core MCU of the bidirectional DC conversion system based on the bidirectional DC-DC unit in the second embodiment;

[0026] Fig.19 is a pulse sequence control block diagram in the third embodiment;

[0027] Fig. 20 is a pulse sequence control block diagram of a bidirectional DC converter in a third embodiment;

[0028] Fig.21 It is a step-up / step-down mode selection unit of the bidirectional DC converter pulse sequence in the third embodiment;

[0029] Fig. 22 is a mode pulse selection unit of the bidirectional DC converter pulse sequence in the third embodiment;

[0030] Fig.23 It is the basic pulse generator unit of the bidirectional DC converter pulse sequence in the third embodiment. DETAILED DESCRIPTION

[0031] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. However, it will be appreciated by those skilled in the art that in the present application, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can also be implemented. The division of the following embodiments is for the convenience of description, and the specific implementation of the present application should not be construed as any limitation, and the various embodiments can be combined and referenced with each other under the premise of no contradiction.

[0032] The first embodiment of the present invention relates to a DC conversion system, such as Figure 1 As shown, the DC conversion system of this embodiment includes: a main power module for realizing power conversion, and a digital control module; wherein the digital control module is realized by a dual-core single chip, the first processing core of the dual-core single chip is used to control the main power module, and the second processing core of the dual-core single chip is used to perform system-level monitoring and management of the DC conversion system.

[0033] In one example, the first processing core is specifically used to control the main power module according to the resources pre-allocated to the first processing core; the second processing core is specifically used to perform system-level monitoring and management of the DC conversion system according to the resources pre-allocated to the second processing core.

[0034] In one example, the resources pre-allocated to the first processing core are determined according to the functions assigned to the first processing core; and the resources pre-allocated to the second processing core are determined according to the functions assigned to the second processing core. Figure 2 As shown, Figure 2 The system architecture of the DC-DC conversion system includes a unidirectional DCDC system. The core of the control system is a dual-core MCU, which includes but is not limited to DSP, ARM, etc. The dual-core MCU includes a first processing core and a second processing core. The main functions of the DCDC conversion system are divided into function A and function B. The first processing core uses chip resource A to complete function A in the DC conversion system. The second processing core uses chip resource B to complete function B in the DC conversion system.

[0035] This embodiment is described by taking the DC-DC unit in the main power module of the DC conversion system as a unidirectional DC-DC unit as an example. Figure 3 As shown, the main power part is the main power module, and the digital control part is the digital control module. The unidirectional DC-DC unit of the main power part includes but is not limited to the single-phase LLC topology. The basic topology of the single-phase full-bridge LLC is as follows Figure 4As shown. The DC bus in the main power module supplies power to the unidirectional DC-DC unit, and the DC-DC unit supplies power to the load. The unidirectional DCDC conversion system also has a digital control module, which is implemented by a dual-core single chip. The first processing core of the dual-core single chip is used to control the main power module, such as controlling the unidirectional DC-DC unit, which mainly includes performance control and system protection functions. Among them, performance control includes but is not limited to steady-state performance, transient performance and efficiency performance. System protection functions include but are not limited to overvoltage protection and overcurrent protection, such as Figure 5 As shown; the second processing core is used for system-level monitoring and management of the DC conversion system, that is, system monitoring. Among them, system monitoring mainly includes communication functions, human-computer interaction functions and other system-level functions. Communication functions include but are not limited to RS485 / CAN, GPS / GSM, WIFI, NB-IOT, eMTC, GPRS and other communication-related functions. Human-computer interaction functions include but are not limited to system status display, control variable transmission and reception, key quantity transmission, and acceleration sensor-related functions. Other functions include anti-theft detection, system sleep, etc. After determining the function, the chip resource allocation of the unidirectional DCDC system is determined according to the performance characteristics of the unidirectional DCDC system and the first processing core and the second processing core, such as Figure 6 As shown, the first processing core, i.e., the first processor, is specifically used to control the main power module according to the resources pre-allocated to the first processing core; the second processing core, i.e., the second processor, is specifically used to perform system-level monitoring and management of the DC conversion system according to the resources pre-allocated to the second processing core. According to the different functions of each processor core, internal chip resources are allocated to it. It should be noted that since the communication functions are basically processed by the second processor, a large amount of chip communication resources are allocated to the second processor, including but not limited to I2C, SCI, SPI, CAN and other communications. The chip resources allocated to the first processing core are A / D sampling, PWM wave generation, storage area 1, interrupt 1, and the chip resources allocated to the second processing core are A / D sampling, GPIO, storage area 2 and communication resources. Based on the above-mentioned functional division and resource allocation, the schematic diagram of the relationship between the peripheral hardware circuit unit and the dual-core MCU is shown as follows Figure 7 As shown, the peripheral circuits of the second processor include: RS485 / CAN, GPS / GSM, WIFI, NB-IOT, eMTC, GPRS, sleep circuit, operation / warning lights, acceleration sensor, DIP switch, and various interfaces; the peripheral circuits of the first processor include sleep control, signal drive, power failure warning, wave-by-wave protection, interlocking, current detection, voltage detection, and lightning protection circuit. The above functions and divisions are all examples and do not limit the detailed division of the functions of the DC conversion system.

[0036] The embodiments of the present invention realize multiple functions of a unidirectional DCDC conversion system with only one chip, without considering the circuit design between multiple chips, thereby reducing the complexity of the circuit design of the system, improving the energy density, shortening the hardware design cycle, and simplifying the coordination and cooperation mode between multiple tasks. In addition, the number of chips is reduced, the energy loss of the main control chip is reduced, the system integration is improved, and the real-time communication is improved.

[0037] The second embodiment of the present invention relates to a DC conversion system. The second embodiment is substantially the same as the first embodiment, except that the second embodiment of the present invention is a bidirectional DC-DC conversion system. The main power module of the bidirectional DC-DC conversion system of this embodiment includes: a bidirectional DC-DC unit or multiple interleaved bidirectional DC-DC units.

[0038] In an example, the resource includes one of the following or any combination thereof: storage resources, interrupt resources, peripheral resources, communication resources, and CPU resources.

[0039] In one example, the control of the main power module includes one of the following or any combination thereof: charging and discharging mode switching, high and low voltage mode switching, voltage regulation and transient control in each mode, and system protection function; the system-level monitoring and management of the DC conversion system includes one of the following or any combination thereof: system sleep control, system anti-theft, human-computer interaction, and control signal reception and transmission; wherein the battery management function is included in the control of the main power module, or, is included in the system-level monitoring and management of the DC conversion system.

[0040] In one example, the functions allocated to the first processing core and the functions allocated to the second processing core are determined according to an application scenario of the DC conversion system and performance characteristics of the first processing core and the second processing core.

[0041] In one example, the DC-DC units in the main power module of the DC conversion system are multiple interleaved bidirectional DC-DC units. The DC-DC units in the main power module of the DC conversion system are multiple interleaved bidirectional DC-DC units, such as Figure 8 As shown, the main power part is a main power module, and the digital control part is a digital control module. In the main power module, the topology structure can be a non-isolated topology, such as a multiple interleaved parallel H bridge, and its topology is as follows Fig. 9 As shown, it can also be an isolated topology, such as multiple dual active bridges, whose topology is as follows Fig.10As shown, in multiple interleaving, the specific topology used is determined according to the specific power level. The forms of isolated topology and non-isolated topology include but are not limited to the two topologies mentioned above. When the bus is energized, the DC bus supplies power to the load, and the energy storage unit is charged through multiple interleaved bidirectional DC-DC units. When the bus is powered off, the DC bus is insufficiently powered, and the energy storage unit is discharged through multiple interleaved bidirectional DC-DC units to power the load, or the multiple interleaved bidirectional DC-DC units and the bus supply power to the load together to ensure normal power supply to the load. The digital control part uses a dual-core MCU as the core processor to replace the original two single-core MCUs. In the dual-core MCU, there will be heterogeneous processors, that is, the functions and performance of the two processors are asymmetric and suitable for different application scenarios. Usually, one of the processors is suitable for communication and human-computer interaction, and the other processor is suitable for the implementation of the control algorithm. Therefore, it is necessary to divide the functions of the processing core according to the bidirectional DC conversion system based on multiple interleaved bidirectional DC-DC units and the performance characteristics of the processing core, so as to better fit the system characteristics and the characteristics of the processing core. In the digital control part, i.e. the digital control module, the first processing core corresponds to the control of the main power module function, which includes bidirectional unit control, and the second processing core corresponds to system monitoring management. Each control function includes different tasks. The task diagram of the bidirectional unit control function is shown in the figure below. Fig.11 As shown in the figure, the tasks include: charge and discharge mode selection and switching, buck-boost mode selection and switching, voltage regulation and transient characteristic control in each mode, system protection functions such as charge and discharge current limiting, overvoltage protection, overcurrent protection, and system monitoring function task diagram as shown in the figure Fig.12 As shown, it includes: battery management, human-computer interaction, communication, protection, etc. The battery management function includes tasks: battery voltage monitoring, temperature monitoring, battery balancing management, battery status calculation, etc. And there is data interaction between the system monitoring function and the bidirectional DCDC control function, including but not limited to the interaction of battery data, the interaction of system protection signals, the interaction of system control quantities, etc. The coupling of the above functions is relatively strong. According to the peripherals and storage resources required by each function, the MCU dual-core and other resources are allocated. Allocating resources can improve the real-time operation of the system, and allocate corresponding resources to the processor according to the interrupts and peripherals required by the task. Finally, observe whether there is communication and collaboration between different processors between each task, and select and configure appropriate communication between processors inside the chip. Fig.13 The block diagram of the dual-core MCU task allocation and resource allocation in the bidirectional DC converter system is visualized. The first processor is responsible for the bidirectional DCDC control function, including charge and discharge mode switching, high and low voltage mode switching, voltage regulation and transient control in each mode, system protection and other tasks. The chip resources required include but are not limited to A / D sampling, PWM wave generation, storage area 1, interrupt 1, etc. Fig.14 is a schematic diagram of the connection between the dual-core MCU and the external hardware circuit unit corresponding to the above task allocation and resource allocation, Fig.14 The functions shown are optional functions, and the actual functions may be less than the above functional units. The second processor is responsible for system monitoring functions, and its tasks include but are not limited to battery management, human-computer interaction, and other system functions. The chip resources required include but are not limited to A / D sampling, GPIO, storage area 2, interrupt 2, CAN / SCI / I2C and other communications. There is communication and collaboration between the first processor and the second processor to complete the data exchange between the systems.

[0042] In another example, the DC-DC unit in the main power module of the DC conversion system is a bidirectional DC-DC unit, such as Fig.15 As shown, the main power part is the main power module, and the digital control part is the digital control module. Unlike the above-mentioned multiple interleaved bidirectional direct current DC-DC units, the bidirectional direct current DC-DC unit in this example is a single-layer isolated or non-isolated topology. In addition, the main power module in this example in the figure is basically the same as the main power module. When the bus is normally energized, the DC bus supplies power to the load, and the energy storage unit is charged through the bidirectional DC-DC unit. When the bus is powered off, the DC bus is insufficiently powered, and the energy storage unit is discharged through the bidirectional DC-DC unit to supply power to the load, or the dual DCDC unit and the bus supply power to the load together to ensure normal load power supply. The difference between this example and the above is mainly that the functions of each core of the dual-core processor in the digital control module have changed significantly. The first processing core is used to control the main power module, which includes: a bidirectional DCDC unit, battery management. In the DC conversion system of the bidirectional direct current DC-DC unit based on a single-layer isolated or non-isolated topology, the first processing core mainly realizes bidirectional unit control and battery management. The second processing core performs system-level monitoring and management of the DC conversion system, namely system monitoring, which mainly includes functions related to human-computer interaction and communication. Fig.16 As shown, at this time, the first processing core completes the control of the bidirectional DCDC unit and the battery management functions. The tasks of bidirectional unit control include: charge and discharge mode selection and switching, buck-boost mode selection, steady-state and transient characteristics, system protection, for example, charge and discharge current limiting, overvoltage protection, overcurrent protection, battery management tasks include but are not limited to battery voltage, temperature and other monitoring, battery balancing control, battery status calculation, SOC / SOH. The second processing core completes the system monitoring function, mainly human-computer interaction and communication related functions. Human-computer interaction includes but is not limited to system status display, bidirectional unit control quantity transmission and reception, system sleep, key quantity detection, and other functions, such as anti-theft detection, system sleep, WIFI control, etc. The chip functions and resource allocation based on the above functions are as follows: Fig.17As shown. The first processor, i.e., the first processing core, is responsible for increased functions, mainly responsible for the object control function, including bidirectional unit control, battery management control and system protection control. The second processor, i.e., the second processing core, is mainly responsible for the process control, i.e., the system monitoring function, including but not limited to human-computer interaction function and other system functions, mainly system monitoring and communication. Since the first processor is responsible for two object controls, at least two interrupts are assigned to it. Because the battery management function is the responsibility of the first control core, related hardware units such as battery voltage, battery temperature, etc. are unbound from the second control core and bound to the first control core. The allocation of the remaining hardware units is the same as that of the bidirectional DC digital control based on multiple bidirectional DC-DC units. The schematic diagram of the matching relationship between the hardware circuit unit and the dual-core processor is shown in Fig.18 As shown, the first processor peripheral hardware unit includes: bidirectional unit circuit, discharge switching circuit, charge switching circuit, battery cell voltage, anti-reverse connection, short circuit protection, external voltage, charge and discharge power supply, telecommunication temperature, battery voltage, power supply circuit, lightning protection circuit, and the second processor peripheral hardware circuit unit includes: anti-theft detection, RS485 / CAN, output dry node, sleep circuit, GPS / GSM, acceleration sensor, various interfaces, operation / warning lights, dip switch, SOC display light, WIFI, and balancing circuit.

[0043] The above resource allocation and functional division of the DC conversion platform based on bidirectional DC-DC units and multiple interleaved bidirectional DC-DC units only provides a solution and does not limit the specific resource allocation and functional division. The DC exchange platform of the dual-core microcontroller unit based on other application scenarios can be designed according to specific needs. Analyze the characteristics and applicable occasions of the first processing core and the second processing core in the dual-core microcontroller unit; determine the control objectives of the system. For example, in a bidirectional DC digital system, the system-level control goal is: the system works stably, reliably and efficiently. The control goal of the bidirectional DCDC unit is to smoothly realize the bidirectional multi-mode flow of energy to achieve superior stability and transient performance. For the battery unit control target, the battery works normally and the voltage is balanced; obtain the functions of the entire control system. For example, in the bidirectional DC conversion system, the important functions are the bidirectional DCDC control function and the system monitoring function. Among them, the bidirectional DCDC control function includes tasks: charging and discharging mode switching, high and low voltage mode switching, voltage regulation and transient control in each mode, system protection function, system monitoring function includes: battery management function, human-computer interaction function, communication function, protection function, other functions, battery management function includes tasks: battery voltage monitoring, temperature monitoring, battery balancing management, etc. And there is data interaction between the system monitoring function and the bidirectional DCDC control function, including but not limited to the interaction of battery data, the interaction of system protection signals, the interaction of system control quantities, etc. The coupling of the above functions is relatively strong; obtain the peripherals and storage resources required for each function. Finally, according to the above analysis, the allocation of MCU dual cores and other resources is carried out. For the resource allocation of the DC control platform, the MCU processor and domain can be allocated according to the control task to allocate storage resources to the first processor and the second processor, that is, the first processor is responsible for the bidirectional energy conversion control function, the second processor is responsible for the system monitoring function, and the subtasks under the corresponding functions are also the responsibility of the corresponding processors. Storage resources are allocated according to their functions. If storage resources are not allocated, when the first processor is using DMA1 and the second processor needs to use DMA1, the second processor will automatically identify the usage status of DMA1 and enter waiting, which will greatly reduce the real-time performance of the system. Therefore, it is necessary to optimize the allocation of storage resources according to the task occupancy; then, interrupts and peripherals are allocated to the dual-core processor according to the peripherals and terminals required by the task. Finally, resources are allocated according to the communication and collaboration between the dual-core processors, that is, observe whether there is communication and collaboration between different processors between each task, and choose to configure appropriate communication between processors inside the chip.

[0044] The second embodiment of the present invention determines the functions of the divided processing cores according to the performance of the processing cores, so that the first processing core and the second processing core can fully utilize their own performance, and pre-allocate resources to the processing cores, so that the DC conversion system can obtain resources in time for scheduling during operation, thereby improving the real-time performance of the system operation and comprehensively improving the efficiency of the DC conversion system.

[0045] The third embodiment of the present invention relates to a DC conversion system. The third embodiment is substantially the same as the second embodiment, except that the third embodiment of the present invention controls the main power module, including: controlling the bidirectional DC-DC unit in the main power module; the digital control module includes: a sampling unit 191 for sampling the battery voltage and bus voltage in the main power module; a mode and pulse selection unit 192 for detecting the working mode of the bidirectional DC-DC unit according to the signal sampled by the sampling unit, and determining a pulse corresponding to the detected working mode according to the detected working mode; a pulse generator 193 for generating a pulse sequence for controlling the bidirectional DC-DC unit according to the pulse determined by the mode and pulse selection unit. The bidirectional DC converter pulse sequence control block diagram of the third embodiment is shown in FIG. Fig.19 shown.

[0046] In one example, the pulse generator includes: a basic pulse generator for generating basic pulses; a pulse combination unit for combining the basic pulses to obtain the pulse sequence. The pulse combination unit is optional, and the mode and pulse selection unit can be before or after the basic pulse generator unit.

[0047] In one example, the working modes include: a boost mode, a buck mode, and a buck-boost mode.

[0048] Take the case where the DC-DC unit in the main power module of the DC conversion system is a multiple interleaved bidirectional DC-DC unit as an example. In this example, the digital control module and the main power module are the same as those in the second embodiment based on multiple interleaved bidirectional DC-DC units. The control functions and resource allocation corresponding to the digital control module and the first processing core and the second processing core are also the same, which will not be repeated here. This embodiment describes the pulse sequence control of the digital control module in the DC conversion system based on multiple interleaved bidirectional DC-DC units. The implementation block diagram of the pulse sequence control of the bidirectional DC converter in the system is shown in FIG. Fig. 20As shown, after the charge and discharge mode is determined, the output side voltage Vo and the input side voltage Vin are determined. In the charging mode, Vo is the battery side voltage and Vin is the bus side voltage. Otherwise, Vo and Vin are opposite. Compare the values ​​of Vin and Vo to determine the current working mode of the converter, where the working mode includes: boost mode, buck mode or buck-boost mode. Different modes require different pulse sequences. The buck-boost mode selection unit is shown in FIG. Fig.21 As shown, Fig.21 In the figure, V1 is the voltage on the DC bus side, V2 is the voltage on the energy storage side, and Vin_L is the voltage threshold for judging whether the DC bus is powered off. Fig. 22 As shown, Vs_L and Vs_H are the allowable range of the difference between Vin and Vo. In this embodiment, the boost mode pulse sequence is PT_Boost, and the buck mode pulse sequence is PT_Buck. Compare the output voltage with the reference voltage to determine whether to generate basic pulses PLx and PHx. According to the current mode conditions and the basic pulses, the required pulse sequence is generated by combining. At this time, the boost-boost mode pulse sequence is generated by combining the boost mode pulse and the buck mode pulse. However, the boost-boost mode pulse sequence can also be set to PT_BuckBoost, and the pulse combination unit can be cancelled. The basic pulse generator unit is shown in FIG. Fig.23 As shown. In this embodiment, the generated drive signal acts on the controlled switch tube of the current mode, and the remaining switch tubes will be in a normally open or normally closed state according to the current mode, and are directly controlled by the mode, which will not be described in detail here. In addition, in this embodiment, the basic pulse sequence can be a voltage type pulse sequence or a current type pulse sequence. Figure 21 to Figure 23 These are all logic analyses of specific units in the control block diagram. When implemented, digital controllers such as DSP, FPGA, etc. can be used to implement the above logic control, and logic circuits can also be used to implement the above functions.

[0049] Compared with the traditional bidirectional DC system, the control of the existing bidirectional converter mostly adopts voltage type control, combined with three mode switching to achieve output voltage regulation. Based on the inherent problems of the voltage type, plus the influence of the right half plane zero point in the Boost mode and Buck-Boost mode, in order to make the converter work stably, the crossover frequency is reduced when adjusting the compensator, resulting in a slow transient response speed of the bidirectional converter. At the same time, the switching of the three modes means that the converter works in three working modes. When using traditional voltage-type control, the compensator needs to be adjusted for each working mode, and the compensator adjustment workload is at least three times the original. In order to solve the above problems, this embodiment applies nonlinear pulse sequence control to the bidirectional converter for the control of the bidirectional DC converter, using a sampling unit, a mode and pulse selection unit, and a pulse generator. Compared with traditional linear control, the pulse sequence control proposed in the embodiment of the present invention improves the transient response of the bidirectional converter in multiple modes, and solves the problem of difficult and complex debugging of the compensator in multiple modes. In addition, in the bidirectional converter, pulse sequence control is used, and a combined optimization scheme of pulses is designed to achieve stable operation of the converter in three working modes, with good stability performance and transient performance, shortening the research and development cycle of the bidirectional converter control strategy.

[0050] It can be seen that the three embodiments of the present invention apply nonlinear pulse sequence control to the bidirectional converter, which not only improves the transient response of the bidirectional converter in multiple modes, solves the problem of difficult and complex debugging of the compensator in multiple modes, and realizes stable operation of the converter in three working modes, has good stability performance and transient performance, and shortens the research and development cycle of the bidirectional converter control strategy. Moreover, by using a dual-core single chip, multiple functions are realized with only one chip, which reduces the complexity of the circuit design of the system, improves the energy density, shortens the hardware design cycle, and does not need to consider the coordinated cooperation mode of multiple tasks between multiple chips, which simplifies the coordinated cooperation mode between multiple tasks. In addition, the number of chips is reduced, and the dual-cores in a chip work alternately to achieve controllable sleep, which reduces the energy loss of the main control chip and increases the degree of system integration. Moreover, when communicating, only the communication between the dual cores needs to be considered, and the dual cores are in the same chip, which improves the real-time performance of communication.

[0051] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A DC conversion system, characterized in that: include: Main power module for power conversion, and digital control module; Wherein, the digital control module is implemented by a dual-core single-chip MCU, the first processing core of the dual-core single chip is used to control the main power module according to the resources pre-allocated to the first processing core, and the second processing core of the dual-core single chip is used to perform system-level monitoring and management of the DC conversion system according to the resources pre-allocated to the second processing core, and the resources include one of the following or any combination thereof: storage resources, interrupt resources, peripheral resources, communication resources, CPU resources; The controlling of the main power module includes: Charging and discharging mode switching, high and low voltage mode switching, and system protection functions, wherein the system protection functions include overvoltage protection, overcurrent protection, and charging and discharging current limiting; The system-level monitoring and management of the DC conversion system includes: Communication function, system sleep control, system anti-theft, human-computer interaction function, control signal transceiver, wherein the human-computer interaction function includes system status display, control variable transceiver, keystroke quantity transmission, and acceleration sensor related functions; Among them, the chip resources allocated to the first processing core include the first A / D sampling, PWM wave generation, the first storage area and interrupt resources; the chip resources allocated to the second processing core include the second A / D sampling, GPIO, the second storage area and communication resources, wherein the communication resources include I2C, SCI, SPI and CAN.

2. The DC conversion system according to claim 1, characterized in that: The peripheral hardware circuit units of the first processing core include: a bidirectional unit circuit, a discharge switching circuit, a charge switching circuit, a current detection circuit, a voltage detection circuit, a sleep control circuit, and a lightning protection circuit.

3. The DC conversion system according to claim 1, characterized in that: The peripheral hardware circuit units of the second processing core include: anti-theft detection circuit, RS485 / CAN, sleep circuit, GPS / GSM, acceleration sensor, operation / warning light, dip switch, SOC display light, WIFI, and balancing circuit.

4. The DC conversion system according to claim 1, characterized in that: The control of the main power module includes: controlling a bidirectional direct current DC-DC unit in the main power module; The digital control module comprises: A sampling unit, used for sampling the electrical signal in the main power module; a mode and pulse selection unit, configured to judge the working mode of the bidirectional direct current DC-DC unit according to the signal sampled by the sampling unit, and determine a pulse corresponding to the detected working mode according to the judged working mode; A pulse generator is used to generate a pulse sequence for controlling the bidirectional direct current DC-DC unit according to the mode and the pulse determined by the pulse selection unit.

5. The DC conversion system according to claim 4, characterized in that: The pulse generator comprises: A basic pulse generator, used for generating a basic pulse; The pulse combination unit is used to combine the basic pulses to obtain the pulse sequence.

6. The DC conversion system according to claim 4, characterized in that: The working modes include: Boost mode, buck mode, and buck-boost mode.

7. The DC conversion system according to claim 1, characterized in that: The resources pre-allocated to the first processing core are determined according to the functions allocated to the first processing core; The resources pre-allocated to the second processing core are determined according to the functions allocated to the second processing core.

8. The DC conversion system according to claim 7, characterized in that: The functions allocated to the first processing core and the functions allocated to the second processing core are determined according to the application scenario of the DC conversion system and the performance characteristics of the first processing core and the second processing core.

9. The DC conversion system according to claim 1, characterized in that: The DC-DC unit in the main power module includes any one of the following: Unidirectional DC-DC unit, bidirectional DC-DC unit, multiple interleaved bidirectional DC-DC unit, multiple interleaved single-phase DC-DC unit.

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