CN106505848A - Start-stop control system and method for high-power bidirectional full-bridge DC-DC converter - Google Patents

Abstract

The invention discloses a kind of start-stop control system of great power bidirectional full-bridge DC DC changers and method; the system includes that two-way full-bridge DC DC changers, signal condition are produced and drive module, protection module, CPLD, single-chip microcomputer and control station with limit monitoring modular, PWM is crossed; the signal condition is connected with two-way full-bridge DC DC changers with the input for crossing limit monitoring modular, and outfan is connected with CPLD and single-chip microcomputer respectively；The outfan of the CPLD is produced with PWM respectively and is connected with the input of drive module and protection module；The PWM is produced and is connected with two-way full-bridge DC DC changers with the outfan of drive module and protection module；It is connected by communication bus between the single-chip microcomputer and CPLD, single-chip microcomputer is connected with control station also by SPI communication bus.The present invention adopts two-way full-bridge DC DC changers, combines to ensure systematic steady state reliability service using the digital-to-analogue of CPLD and single-chip microcomputer.

Description

Start-stop control system and method for high-power bidirectional full-bridge DC-DC converter

technical field

The invention relates to a start-stop control system and method of a DC-DC converter, in particular to a start-stop control system and method of a high-power bidirectional full-bridge DC-DC converter, belonging to the field of switching converters.

Background technique

As the country puts forward further requirements on energy consumption, bidirectional full-bridge DC-DC converters that can realize energy storage and release in multi-quadrant working systems have been widely favored and recognized. However, the DC-DC converter is a high-frequency switching converter, and the work of the system is susceptible to electromagnetic interference. When the system is disturbed and fails, it cannot guarantee that the system can be stopped reliably or restarted reliably. Moreover, in high-power places, the start and stop of the system will also cause sudden changes in voltage and current, which may cause repeated work of the system and overload the system. Further, the bidirectional working nature of the bidirectional full-bridge DC-DC converter also makes the start-up control of the bidirectional full-bridge DC-DC converter more complicated.

After reviewing the relevant literature, most of the start-stop circuits for high-power bidirectional full-bridge DC-DC converters still stay in the soft-start mode, and the soft-start is aimed at the soft-start of the main topology, and does not address the problems that occur during system startup. A reliable way to start to deal with various problems.

Contents of the invention

The purpose of the present invention is in order to solve above-mentioned defective of prior art, provide a kind of start-stop control system of high-power bidirectional full-bridge DC-DC converter, this system adopts bidirectional full-bridge DC-DC converter, utilizes CPLD and single-chip microcomputer The combination of digital and analog to ensure the stable and reliable operation of the system.

Another object of the present invention is to provide a start-stop control method of a high-power bidirectional full-bridge DC-DC converter based on the above system.

The purpose of the present invention can be achieved by taking the following technical solutions:

Start-stop control system of high-power bidirectional full-bridge DC-DC converter, including bidirectional full-bridge DC-DC converter, signal conditioning and over-limit monitoring module, PWM generation and driving module, protection module, CPLD, single-chip microcomputer and console, The input end of the signal conditioning and over-limit monitoring module is connected to the bidirectional full-bridge DC-DC converter, and the output end is connected to the CPLD and the single-chip microcomputer respectively; the output end of the CPLD is respectively connected to the PWM generation and input of the drive module and the protection module The PWM generation is connected with the output terminals of the drive module and the protection module with the bidirectional full-bridge DC-DC converter; the single-chip microcomputer is connected with the CPLD through the communication bus, and the single-chip microcomputer is also connected with the console through the SPI communication bus.

As a preferred solution, the bidirectional full-bridge DC-DC converter includes four IGBT modules and a transformer, wherein two IGBT modules are connected to the high-voltage end of the transformer as step-down IGBT modules, and the other two IGBT modules are connected to the high voltage end of the transformer. The low-voltage side of the transformer is connected as a step-up IGBT module.

As a preferred solution, the four IGBT modules all use the half-bridge module SKM50GB12T4.

As a preferred solution, the PWM generating and driving module includes a step-down PWM controller and a step-up PWM controller.

As a preferred solution, the step-down PWM controller adopts the UC3825 chip of T1 Company, and the step-up PWM controller adopts the UC3875 chip of T1 Company.

As a preferred solution, the protection module includes multiple overvoltage protection circuits and multiple start-stop protection circuits.

As a preferred solution, the overvoltage protection circuit includes a single-limit comparator and a first resistor, the input terminal of the single-limit comparator is connected to the supercapacitor voltage, and the output terminal is connected to the first resistor; the start-stop protection circuit It includes a hysteresis comparator, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a diode, the input terminal of the hysteresis comparator is connected to the supercapacitor voltage through the second resistor, and the output terminal is connected to the first resistor through the third resistor. The four resistors are connected, the anode of the diode is connected to the output end of the hysteresis comparator, and the cathode is connected to the input end of the hysteresis comparator through the fifth resistor.

As a preferred solution, the single-chip microcomputer adopts the single-chip microcomputer of TI Company model as MSP430F5438, and the described CPLD adopts the model of Altera Company and is 5M160ZE64; the described single-chip microcomputer and CPLD adopt 7 logical I/Os to carry out logic level one-way communication, realize the whole System information exchange.

Another object of the present invention can be achieved by taking the following technical solutions:

Based on the start-stop control method of the high-power bidirectional full-bridge DC-DC converter of the above-mentioned system, the method includes the following steps:

S1. After starting up, initialize the fast shutdown I/O to a low level through the hardware circuit, indicating that the system is not allowed to start at this time;

S2. The single-chip microcomputer reads the fault indication status. If there is no fault at this time, the single-chip microcomputer will interrupt the online square wave through the timer, and the CPLD will judge whether the single-chip microcomputer is working normally by cyclically monitoring the online square wave. At the same time, the single-chip microcomputer reads the control mode of the console. Indicate, and through the control mode switch, indicate that the control mode required by the CPLD is the voltage control mode or the current control mode;

S3. The CPLD reads the control mode indication after confirming that the single-chip microcomputer is online, and monitors the status of the signal conditioning and over-limit monitoring module. If the data of the signal conditioning and over-limit monitoring module indicates that the system is normal, enable PWM generation and drive Module, and give a power direction indication, indicating whether the power direction of the single chip microcomputer is the boosting direction or the bucking direction; if there is no fault in the startup, the system will perform steady-state control to realize the system function;

S4. If there is a failure in the startup process, the communication of the system will be blocked, and the system will enter the protection mode, and the fault indication I/O will be modified to a high level, indicating that the system has failed, and the single-chip microcomputer sends an indication to the console that the system enters the protection state ;

S5. If the system enters the protection state, the CPLD maintains the fault indication, and the timer of the single-chip microcomputer judges the fault time. If the system fault indication is not cut off within 1 minute, the single-chip microcomputer sends an instruction to turn off the system to the console, and the console Automatically modify the fast shutdown I/O to low level, start the disabled mode, and wait for the next command from the console; if the system fault disappears within 1 minute, enter the fault disappearance confirmation program, and judge by the timer for 30s. Time no longer enters the system failure state, then re-enter step S2;

S6. If the system console indicates shutdown, the MCU will give a quick shutdown instruction, and the CPLD will instruct the system to enter the shutdown mode, control the PWM generation, drive module and protection module to cut off the energy source supply and release the energy of the magnetic element. When the signal conditioning and over-limit monitoring When the module indicates that the magnetic component has no energy storage, it disables all PWM signals and enters idle mode to wait for console commands.

As a preferred solution, the signal conditioning and over-limit monitoring module uses a precision voltage source in the same voltage channel to perform primary voltage division, which is divided into two levels: high voltage and low voltage; and then uses precision resistors to perform secondary voltage The high voltage is divided into: emergency resistance threshold, overvoltage threshold and high voltage hysteresis value; the low voltage is divided into: rated reference value, low voltage hysteresis value and undervoltage threshold; among them, the threshold voltage is passed through the single limit comparator Realization, at the moment when the monitoring voltage touches the threshold, the hardware protection is realized immediately through the hardware; the hysteresis value voltage is realized through the hysteresis comparator, which satisfies the voltage mutation caused by the sudden change of the load during the start-stop process, and finally causes the system to start repeatedly The bad state of stopping; in the same way, the current signal and temperature signal are divided in the same way.

Compared with the prior art, the present invention has the following beneficial effects:

1. The main topology of the circuit of the present invention adopts a bidirectional full-bridge DC-DC converter, and uses a CPLD as a digital control part, and a single-chip microcomputer as an analog control part, through signal conditioning and over-limit monitoring module, protection module and state synthesis of the console Various information during the start-stop process of the bidirectional full-bridge DC-DC converter, and continuously inquire about the working status of the CPLD and single-chip microcomputer in the system through the communication bus, and integrate all information for flow control to realize high-power bidirectional full-bridge DC-DC conversion Reliable start and stop of the device.

2. The signal conditioning and over-limit monitoring module of the present invention adopts a single-limit comparator and a hysteresis comparator, which can prevent the system from being repeatedly started due to a sudden change in the start-stop voltage and current, and at the same time ensure that the system fails in the first time Disabled mode protected by hardware.

3. The single-chip microcomputer and CPLD of the present invention use seven logic I/Os to carry out logic-level one-way communication to realize the information interaction of the entire system. The functions of the seven logic I/Os include inductor current status indication, control mode switching indication, single-chip Power direction change application, MCU online square wave indication, fast shutdown indication, CPLD power direction indication, fault indication, since all logic I/Os work in one direction, reliability can be guaranteed.

4. The present invention uses one-way I/O level communication, and the reliability of the communication is very high. At the same time, because there are seven communication buses, the communication information is full, which can ensure that the system can quickly and accurately grasp the various components of the system during the startup process. Whether the module works normally and instructs other systems to drive to a certain mode to ensure the reliable operation of the system during the start and stop process.

Description of drawings

Fig. 1 is a structural block diagram of the start-stop control system of the high-power bidirectional full-bridge DC-DC converter of the present invention.

Fig. 2 is a control diagram of the bidirectional full-bridge DC-DC converter of the present invention.

FIG. 3 is a schematic structural diagram of the half-bridge module SKM50GB12T4 of the present invention.

FIG. 4 is a schematic circuit diagram of the step-down IGBT module of the present invention.

FIG. 5 is a schematic circuit diagram of the boost IGBT module of the present invention.

Fig. 6 is a schematic diagram of the driving circuit of the step-down IGBT module and the step-up IGBT module of the present invention.

FIG. 7 is a schematic diagram of the step-down PWM controller of the present invention.

Fig. 8 is a schematic diagram of the step-up PWM controller of the present invention

FIG. 9 is a schematic diagram of the overvoltage protection circuit in the protection module of the present invention.

Fig. 10 is a schematic diagram of the start-stop protection circuit in the protection module of the present invention.

FIG. 11 is a schematic diagram of voltage division by the signal conditioning and over-limit monitoring module of the present invention.

Fig. 12 is a schematic diagram of the over-limit monitoring circuit in the signal conditioning and over-limit monitoring module of the present invention.

FIG. 13 is a schematic diagram of the inductor current conditioning circuit in the signal conditioning and over-limit monitoring module of the present invention.

FIG. 14 is a schematic diagram of the communication bus between the single-chip microcomputer and the CPLD of the present invention.

Fig. 15 is a flow chart of the start-stop control method of the high-power bidirectional full-bridge DC-DC converter of the present invention.

detailed description

The present invention will be further described in detail below in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example 1:

As shown in Figure 1, the start-stop control system of the high-power bidirectional full-bridge DC-DC converter of the present embodiment includes a bidirectional full-bridge DC-DC converter, signal conditioning and overlimit monitoring module, PWM (Pulse Width ModulatI/On , pulse width modulation) generation and drive module, protection module, CPLD (Complex Programmable Logic Device, complex programmable logic device), single-chip microcomputer and console; The input terminal of described signal conditioning and over-limit monitoring module and bidirectional full-bridge DC- The DC converter is connected to monitor the voltage, current and temperature signals of the bidirectional full-bridge DC-DC converter, and the output terminals are respectively connected to the CPLD and the single-chip microcomputer; the output terminals of the CPLD are respectively connected to the PWM generation and input of the drive module and the protection module The output terminals of the PWM generation and the drive module and the protection module are connected with the bidirectional full-bridge DC-DC converter, and the driving power circuit realizes power conversion; the single-chip microcomputer is connected with the CPLD through the communication bus, and the single-chip microcomputer is also connected through the SPI The communication bus is connected to the console and interacts with the console.

The control of the bidirectional full-bridge DC-DC converter is shown in Figure 2, the controller shown in the figure refers to CPLD, single-chip microcomputer, CPLD as the digital control part, single-chip microcomputer as the analog control part.

The bidirectional full-bridge DC-DC converter includes four IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) modules and a transformer, and the four IGBT modules all adopt the half-bridge module SKM50GB12T4, and the structure of each half-bridge module SKM50GB12T4 As shown in Figure 3, two of the IGBT modules are connected to the high-voltage end of the transformer as a step-down IGBT module, and the connection diagram is shown in Figure 4, and the other two IGBT modules are connected to the low-voltage end of the transformer as a step-up IGBT module, its connection diagram is shown in Figure 5; the driving circuit of the buck IGBT module and boost IGBT module is shown in Figure 6. The input signal of PWM is PWMin input to resistor R4 and then connected to optocoupler TLP152. The output level of optocoupler TLP152 is between VDD+15_D2 and VEE-15_D2. The high and low level VO is selected by D1 and D2, so that the drive The signal realizes fast switching and slow switching to protect the driving stage of the IGBT tube from damage; the bidirectional tube D7 is to prevent the driving signal from exceeding the maximum voltage of 20V required by the driving level; capacitors C9, C11, C14 and C15 and voltage regulator tubes D5 and D10 The power decoupling and voltage regulation of the optocoupler are realized.

The PWM generating and driving module includes a step-down PWM controller and a step-up PWM controller. The step-down PWM controller adopts the UC3825 chip of T1 Company. As shown in FIG. 7, BuckCurrentSet is input to the NI of the step-down controller UC3825. After the pin, modify the falling edge of the output PWM through the internal oscillator and comparator, thereby changing the duty cycle of the output PWM to achieve the effect of PWM duty cycle control. Among them, Ramp_Buck is the compensation input pin, and the output PWM waveform is divided into two channels, which are BUCK_AC and BUCK_BD; the boost PWM controller adopts the UC3875 chip of T1 Company, as shown in Figure 8. Similarly, UC3875 uses the input signal BoostCurrentSet and The slope compensation signal Ramp_Boost is compared with the oscillator and comparator inside the chip to modify the relative phase of the output PWM, and output four PWM signals BOOST_A to BOOST_D with different phases to achieve the effect of PWM duty cycle control.

The protection module includes a plurality of overvoltage protection circuits and a plurality of start-stop protection circuits. The overvoltage protection circuit is shown in FIG. The input terminal of the comparator LM319 is connected to the supercapacitor voltage, and the output terminal is connected to the first resistor R117. When the super voltage SuperCapVolt exceeds the set voltage SuperCapVolt_Set, the OC gate output of U11A of the single-limit comparator LM319 is pulled up to VDDA3.3 high level through the first resistor R117, otherwise the output is low level.

The start-stop protection circuit is shown in Figure 10, comprising a hysteresis comparator (TL074B), a second resistor R120, a third resistor R126, a fourth resistor R134, a fifth resistor R113 and a diode, the hysteresis comparator The input terminal of TL074B is connected to the supercapacitor voltage through the second resistor R120, the output terminal is connected to the fourth resistor R134 through the third resistor R126, the positive pole of the diode is connected to the output terminal of the hysteresis comparator TL074B, and the negative pole is connected to the fifth resistor R113 Connect with the input terminal of hysteresis comparator TL074B. When the super voltage SuperCapVolt exceeds the set voltage SuperCapVolt_Set, U9A of the hysteresis comparator TL074B outputs a high level, which is close to VCC12, and outputs a SuperCapVolt_StageH signal of about 3.3V through the third resistor R126 and the fourth resistor R134. Otherwise, output low level.

As shown in Figure 11, in order to suppress electromagnetic interference and sudden load changes when starting and stopping, the signal conditioning and over-limit monitoring module uses a precision voltage source in the same voltage channel to perform a first-level voltage division, which is divided into high voltage and low voltage Two levels; then use precision resistors for secondary voltage division, high voltage is divided into: emergency resistance threshold, overvoltage threshold and high voltage hysteresis value; low voltage is divided into: rated reference value, low voltage hysteresis value and undervoltage threshold ;Among them, threshold voltages (emergency resistance threshold, overvoltage threshold, rated reference value, undervoltage threshold) are all realized by a single-limit comparator, and when the monitoring voltage touches the threshold, hardware protection is immediately implemented through hardware; hysteresis The ring value voltage (high-voltage hysteresis value, low-voltage hysteresis value) is realized by the hysteresis comparator, which satisfies the harsh state of the voltage mutation caused by the sudden change of the load during the start-stop process, which finally leads to the repeated start-stop of the system; similarly, for The current signal and temperature signal are divided in the same way; these signals are aimed at objects including: primary voltage and current, secondary voltage and current, transformer current, inductor current and four temperature measurements on the heat sink, a total of 10 measurement parameters; among them, the signal The principle of the over-limit monitoring circuit in the conditioning and over-limit monitoring module is shown in Figure 12. When the voltage of the supercapacitor exceeds the emergency resistance threshold, the single-limit comparator outputs a high level to enable the resistance resistance to release energy; when the super capacitor When the voltage of the capacitor exceeds the overvoltage threshold, the single-limit comparator sends an overvoltage prompt to the CPLD for protection; when the supercapacitor is between the high-voltage and low-voltage hysteresis values, it sends a high-voltage hysteresis signal or a low-voltage hysteresis signal to the CPLD through the hysteresis comparator. Ring signal; when the supercapacitor voltage is lower than the undervoltage threshold, the single-limit comparator sends a low-voltage prompt to the CPLD for protection; if the entire process system is normal, the voltage is given by the rated reference value for the input of the control system.

As shown in Figure 13, the inductor current conditioning circuit in the signal conditioning and over-limit monitoring module, the circuit rectifies the inductor current and sends it to two different rectification circuits respectively. When charging the super capacitor, the inductor current is negative. At this time The inductor current is conditioned by the two operational amplifiers U14D and U14A, and the inductor current becomes positive after conditioning. When the supercapacitor is discharged outwards, the input impedance is enhanced, the output impedance is reduced, and the integrity of the signal is ensured to obtain an accurate conditioning signal after conditioning by the two operational amplifiers U14C and U14B.

Described CPLD can adopt the model of Altera Company to be 5M160ZE64, and described single-chip microcomputer can adopt the single-chip microcomputer of TI Company model to be MSP430F5438; Described single-chip microcomputer and CPLD adopt 7 logic I/Os to carry out logic level one-way communication, realize the information interaction of the whole system , the functions of the seven logical I/Os are shown in Figure 14: 1) Inductor current status indication; 2) Control mode switching indication; 3) Single-chip power direction change application; 4) Single-chip online square wave indication; 5) Fast Shutdown indication; 6) CPLD power direction indication; 7) fault indication; all logic I/Os work in one direction to ensure reliability.

As shown in FIG. 15, this embodiment also provides a start-stop control method of a high-power bidirectional full-bridge DC-DC converter, which is implemented based on the above-mentioned system and includes the following steps:

S1. After starting up, initialize the fast shutdown I/O to a low level through the hardware circuit, indicating that the system is not allowed to start at this time;

S2. The single-chip microcomputer reads the fault indication status. If there is no fault at this time, the single-chip microcomputer will interrupt the online square wave through the timer, and the CPLD will judge whether the single-chip microcomputer is working normally by cyclically monitoring the online square wave. At the same time, the single-chip microcomputer reads the control mode of the console. Indicate, and through the control mode switching, indicate that the control mode required by the CPLD is the voltage control mode or the current control mode;

S3. The CPLD reads the control mode indication after confirming that the single-chip microcomputer is online, and monitors the status of the signal conditioning and over-limit monitoring module. If the data of the signal conditioning and over-limit monitoring module indicates that the system is normal, enable PWM generation and drive Module, and give the power direction indication, indicating whether the power direction of the MCU at this time is the boost direction or the buck direction. At this time, according to the control mode and power direction of the console, the system can already work in a certain working mode. ; If there is no fault in the startup, the system will carry out steady-state control to realize the system function;

S4. If there is a failure in the startup process, the communication of the system will be blocked, and the system will enter the protection mode, and the fault indication I/O will be modified to a high level, indicating that the system has failed, and the single-chip microcomputer sends an indication to the console that the system enters the protection state ;On the one hand, cut off the energy supply of the energy source to prevent the system from continuing to store energy and eventually damage the system; on the other hand, turn on the protection module to release the energy of the magnetic element through the resistance to prevent the shutdown spike from damaging the system;

S5. If the system enters the protection state, the CPLD maintains the fault indication, and the timer of the single-chip microcomputer judges the fault time. If the system fault indication is not cut off within 1 minute, the single-chip microcomputer sends an instruction to turn off the system to the console, and the console Automatically modify the fast shutdown I/O to low level, start the disabled mode, and wait for the next command from the console; if the system fault disappears within 1 minute, enter the fault disappearance confirmation program, and judge by the timer for 30s. Time no longer enters the system failure state, then re-enter step S2;

S6. If the system console indicates shutdown, the MCU will give a quick shutdown instruction, and the CPLD will instruct the system to enter the shutdown mode, control the PWM generation, drive module and protection module to cut off the energy source supply and release the energy of the magnetic element. When the signal conditioning and over-limit monitoring When the module indicates that the magnetic element has no energy storage, it disables (that is, from enable to disable) all PWM signals and enters idle mode to wait for console commands.

In summary, the circuit main topology of the present invention adopts a bidirectional full-bridge DC-DC converter, and uses a CPLD as a digital control part, a single-chip microcomputer as an analog control part, through signal conditioning and over-limit monitoring module, protection module and console The state synthesizes various information during the start-stop process of the bidirectional full-bridge DC-DC converter, and continuously inquires the working status of the CPLD and single-chip microcomputer in the system through the communication bus, and integrates all information for flow control to realize high-power bidirectional full-bridge DC - Reliable start and stop of DC converters.

The above is only a preferred embodiment of the patent of the present invention, but the scope of protection of the patent of the present invention is not limited thereto. Equivalent replacements or changes to the technical solutions and their inventive concepts all fall within the scope of protection of the invention patent.

Claims (10)

1. the start-stop control system of great power bidirectional full-bridge DC-DC converter, it is characterised in that：Become including two-way full-bridge DC-DC Parallel operation, signal condition are produced and drive module, protection module, CPLD, single-chip microcomputer and control station with limit monitoring modular, PWM is crossed, The signal condition with cross limit monitoring modular input be connected with two-way full-bridge DC-DC converter, outfan respectively with CPLD It is connected with single-chip microcomputer；The outfan of the CPLD is produced with PWM respectively and is connected with the input of drive module and protection module；Institute State PWM and produce and be connected with two-way full-bridge DC-DC converter with the outfan of drive module and protection module；The single-chip microcomputer with It is connected by communication bus between CPLD, single-chip microcomputer is connected with control station also by SPI communication bus.

2. the start-stop control system of great power bidirectional full-bridge DC-DC converter according to claim 1, it is characterised in that： The two-way full-bridge DC-DC converter includes four IGBT modules and a transformator, two of which IGBT module and transformator High-pressure side connection, used as blood pressure lowering IGBT modules, two other IGBT module is connected with the low-pressure end of transformator, used as boosting IGBT modules.

3. the start-stop control system of great power bidirectional full-bridge DC-DC converter according to claim 2, it is characterised in that： Four IGBT modules adopt half-bridge module SKM50GB12T4.

4. the start-stop control system of great power bidirectional full-bridge DC-DC converter according to claim 1, it is characterised in that： The PWM is produced includes buck PWM controller and boosting PWM controller with drive module.

5. the start-stop control system of great power bidirectional full-bridge DC-DC converter according to claim 4, it is characterised in that： UC3825 chip of the buck PWM controller using T1 companies, UC3875 core of the boosting PWM controller using T1 companies Piece.

6. the start-stop control system of great power bidirectional full-bridge DC-DC converter according to claim 1, it is characterised in that： The protection module includes multiple overvoltage crowbars and multiple start and stop protection circuits.

7. the start-stop control system of great power bidirectional full-bridge DC-DC converter according to claim 6, it is characterised in that： The overvoltage crowbar includes single limit comparator and first resistor, the input termination super capacitor electricity of single limit comparator Pressure, outfan are connected with first resistor；The start and stop protection circuit include hysteresis comparator, second resistance, 3rd resistor, the 4th Resistance, the 5th resistance and diode, the input of the hysteresis comparator connect super-capacitor voltage, outfan by second resistance It is connected with the 4th resistance by 3rd resistor, the positive pole of the diode is connected with the outfan of hysteresis comparator, and negative pole passes through 5th resistance is connected with the input of hysteresis comparator.

8. the start-stop control system of great power bidirectional full-bridge DC-DC converter according to claim 1, it is characterised in that： Single-chip microcomputer of the single-chip microcomputer using TI companies model MSP430F5438, the CPLD adopt altera corp's model 5M160ZE64；The single-chip microcomputer and CPLD carry out logic level one-way communication using 7 logical I/Os, realize the letter of whole system Breath interaction.

9. the on off control method based on the great power bidirectional full-bridge DC-DC converter of system described in claim 1-8, its feature It is：The method comprising the steps of：

Indicate now not allowing activation system for low level by the quick I/O that shuts down of hardware circuit initialization after S1, start；

S2, single-chip microcomputer read failure instruction state, if now fault-free, single-chip microcomputer provides online side by timer interruption Ripple, CPLD judge single-chip microcomputer whether normal work by the online square wave of circulatory monitoring, while single-chip microcomputer reads the control of control station Molding formula is indicated, and indicates that the control model that CPLD is required is voltage mode control or current control mould by control mode switch Formula；

S3, CPLD confirm single-chip microcomputer online in the case of read control model indicate, and monitoring signals conditioning with cross limit monitoring The state of module, if with the data for crossing limit monitoring modular, signal condition indicates that system is without exception, enables PWM and produces and drive Module, and power direction instruction is given, indicate that the power direction that single-chip microcomputer now works is boosting direction or blood pressure lowering direction；If Start fault-free, then system carries out homeostatic control and realizes systemic-function；

If S4 start-up courses break down, the communication of system will be blocked, and system then enters protected mode, and modification failure refers to Show I/O for high level, indicate that system failure, single-chip microcomputer send the instruction that system enters guard mode to control station；

If S5 systems enter guard mode, CPLD maintains indicating fault, the intervalometer of single-chip microcomputer to sentence fault time Disconnected, if within 1min, the system failure indicates not cut away, then single-chip microcomputer sends the instruction for turning off system, control station to control station Automatically for low level, disability pattern starts the quick I/O that shuts down of modification, waits control station to instruct next time；If within 1min, system Failure vanishes, then enter failure vanishes and confirm program, carry out 30s judgements by intervalometer, if this period does not enter back into system Malfunction, then reenter step S2；

If S6 system control positions indicate to shut down, single-chip microcomputer provides quick shutdown instruction, and CPLD indicates that system is entered and shuts down mould Formula, control PWM are produced and are supplied and discharge magneticss energy with drive module and protection module cut-out energy source, work as signal condition With all pwm signals to enter idle pulley etc. to be controlled of when crossing limit monitoring modular and indicating that magneticss noenergy is stored, disabling Platform is instructed.

10. the on off control method of great power bidirectional full-bridge DC-DC converter according to claim 9, it is characterised in that： The signal condition carries out voltage order one division with limit monitoring modular precision voltage source used in same voltage channel is crossed, and draws It is divided into two grades of high voltage and low-voltage；Secondary voltage division is carried out again with precision resistance, high voltage is divided into：Urgent resistance consumption The stagnant ring value of threshold value, overvoltage threshold and high pressure；Low-voltage is divided into：The stagnant ring value of nominal reference, low pressure and brownout threshold；Wherein, Threshold value class voltage is realized by single limit comparator, in the moment that monitoring voltage touches threshold value, is realized by hardware at once hard Part is protected；Stagnant ring value class voltage is realized by hysteresis comparator, meets and caused voltage in shutdown process by load changing Mutation finally results in the badness of system repeatedly start and stop；In the same manner, same division is carried out to current signal and temperature signal.