Diagnostic method and device for vehicle-mounted high-voltage power generation module

Abstract

The invention discloses a diagnosis method and device for a vehicle-mounted high-voltage power generation module. A motor control unit, a high-voltage distribution box control unit, a power supply control unit and a power generation controller are used for carrying out preliminary diagnosis on faults and fault levels related to the motor control unit, the high-voltage distribution box control unit, the power supply control unit and the power generation controller respectively; sending the preliminary diagnosis result data with the fault level information to a power generation controller; the power generation controller stores the preliminary diagnosis result data and periodically received real-time data in a memory, and updates and stores the data according to whether a fault occurs in the data; grading the severity of the fault, and converting the fault into a corresponding fault code; the power generation controller carries out summary analysis and sends the fault code and the severity to the display terminal; and determining a final fault diagnosis result and executing corresponding protection measures. A total-score secondary diagnosis mode is adopted, so that the cost is saved; the diagnosis accuracy is improved; and data of a period of continuous time before and after the fault is recorded, so that problems can be quickly analyzed and solved.

Description

Technical Field

[0001] The present invention relates to the technical field of on-board high-voltage power generation for engine-driven vehicles, and in particular to a diagnosis method and device for an on-board high-voltage power generation block. Background Art

[0002] The engine is used as the driving source in the vehicle, but many high-voltage devices need to be equipped with an on-board high-voltage power generation block, or the vehicle is used as a mobile high-voltage power source to provide high-voltage electricity to other equipment at different locations. The power generation block converts the kinetic energy of the engine into electrical energy output. The power generation block is mainly composed of a three-phase motor, a motor control unit, a supercapacitor, a power management unit, a high-voltage distribution box, a high-voltage distribution box control unit and a power generation controller. The current diagnostic method for on-board high-voltage power generation systems on the market is relatively simple, and actual faults are often missed, falsely reported, and inaccurately positioned. Faults are reported but prompts and protections cannot be given. The purpose of the present invention is to allow the on-board high-voltage power generation block to have a more complete diagnostic function, improve the accuracy and timeliness of fault alarms, record key data for user analysis, and perform reasonable protection responses when faults occur to maintain the safety of the system and personnel. Summary of the invention

[0003] In view of the above defects or improvement needs of the prior art, the present invention aims to solve the problem that the current diagnostic method for the on-board high-voltage power generation system on the market is relatively simple, and often results in missed faults, false faults, inaccurate positioning, and faults being reported but no prompts or protection being provided.

[0004] In order to achieve the above object, the present invention provides a method for diagnosing a vehicle-mounted high-voltage power generation block, characterized in that it comprises the following steps:

[0005] (a) The motor control unit, high-voltage distribution box control unit, power supply control unit and power generation controller respectively perform preliminary diagnosis on the faults and fault levels related to themselves;

[0006] (b) sending preliminary diagnosis result data with fault level information to the power generation controller;

[0007] (c) The power generation controller stores the preliminary diagnosis result data and the real-time data of the motor control unit, the high-voltage distribution box control unit, and the power supply control unit received periodically in the memory, and updates and stores the data according to whether the power generation block has a fault;

[0008] (d) The fault severity is graded according to the degree of fault hazard, and the received faults and the fault itself are converted into corresponding fault codes; the power generation controller performs summary analysis and sends the fault code and severity to the display terminal; the final fault diagnosis result is determined and the corresponding protection measures are implemented.

[0009] Furthermore, in step (a), the preliminary diagnostic items of the motor control unit include:

[0010] -Motor control voltage;

[0011] -Motor stator temperature;

[0012] - IGBT temperature;

[0013] - Motor control unit bus voltage;

[0014] -Motor rotor speed;

[0015] - Motor phase current.

[0016] Furthermore, in step (a), the preliminary diagnosis items of the high-voltage distribution box control unit include:

[0017] -High voltage distribution box control circuit voltage;

[0018] -Insulation status of high voltage distribution box;

[0019] -The voltage at the rear end of the main relay of the high-voltage distribution box load;

[0020] -Grounding status of high voltage distribution box.

[0021] Furthermore, in step (a), the preliminary diagnosis items of the power control unit include:

[0022] -Supercapacitor cell voltage;

[0023] -Total voltage of supercapacitor busbar;

[0024] -Supercapacitor bus voltage sensor status;

[0025] - Individual capacitor temperature;

[0026] - Individual capacitor temperature, total battery voltage and ambient temperature

[0027] -Capacitor package high temperature area temperature;

[0028] -Power supply control circuit voltage;

[0029] The single capacitor temperature diagnosis method is as follows: number the temperature of the single capacitor, and calculate the upper and lower limits of the temperature deviation of the single capacitor according to the temperature of all single capacitors and the total voltage of the battery. V-total battery voltage, T i -The temperature of the i-th single capacitor; if the temperature of the j-th single capacitor is T j If the limit is exceeded, the temperature of the jth capacitor is reported as excessive.

[0030] Among them, the temperature of a single capacitor, the total voltage of the battery and the ambient temperature, the diagnosis method is: calculation V-total battery voltage, T0-ambient temperature; if the temperature of cell j is T j If the temperature of the jth capacitor cell is higher than the first level threshold T′, a first level fault of over-temperature of the jth capacitor cell is reported; j If the temperature Ti of the jth capacitor cell is higher than the second-level fault threshold of 1.2T′, a second-level fault of excessive temperature change of the jth capacitor cell will be reported; if the temperature Ti of the jth capacitor cell is higher than the second-level fault threshold of 1.4T′, a third-level fault of excessive temperature change of the jth capacitor cell will be reported.

[0031] Furthermore, in step (a), the power generation controller also performs the following diagnosis:

[0032] -Communication status with each control unit;

[0033] -Communication status with external controllers;

[0034] -Relay control status;

[0035] -Cooling system status;

[0036] -Motor speed consistency;

[0037] - Reasonableness of motor power.

[0038] Furthermore, the step (c) updates and saves the data according to whether the power generation block fails. The specific method is as follows: (1) the power generation controller stores the data in the RAM; (2) it is determined whether a fault occurs. If no fault occurs, the data in the RAM N cycles ago is deleted. If yes, the next step is continued.

[0039] The specific method of deleting the data N cycles ago in RAM is as follows: the power generation controller saves the received real-time data stream in RAM, takes the current time as zero point as time T, the diagnostic system communication cycle is Xms, Xms before zero point is time T-1, 2Xms before zero point is time T-2, 3Xms before zero point is time T-3, and so on. Set to record N cycle data. At the current moment, the RAM saves the data streams of time T, T-1, T-2...T-N+1. As time continues to advance Xms to time T+1, RAM saves the data stream of time T+1, erases the data of time T-N+1, and there are still N cycles in RAM. period data; if the power generation controller receives or detects a fault at time T* and determines the fault group, the data related to the group in each cycle from T*-N+1 to T* is saved to the EEPROM, and the data related to the group in the last three cycles, namely T*+1, T*+2, and T*+3, is also saved to the EEPROM; the information saved in the EEPROM still exists after the power is turned off. The EEPROM can store up to M faults and data information related to the faults. If the storage reaches the upper limit, the original fault will be erased and the new fault will be stored when a new fault occurs. The faults with lower severity will be erased first, and then the faults with the earliest occurrence time will be erased.

[0040] Furthermore, in step (a), the faults are divided into three levels, and the power generation controller performs different protection measures according to the fault level:

[0041] There are no restrictions for level 1 failures;

[0042] Second level fault sends power limit command and limit value;

[0043] For level 3 faults, emergency high voltage power reduction operation shall be performed;

[0044] Among them, the limit value sent by the secondary fault is determined by the vehicle speed, motor speed, and bus voltage of the motor control unit: Calculate the limit power: P-external characteristic power obtained from the motor speed; v-reference vehicle speed; v′-actual vehicle speed. If the actual vehicle speed is less than the reference vehicle speed, v′=v; V-reference voltage; V′-actual voltage).

[0045] Further, the method further comprises the following steps:

[0046] (e) When multiple faults occur in a short period of time, the power generation controller determines the root cause through analysis; the determination principle is: determine the initial time when different data are lower than the threshold. If data A is lower than the threshold first, and data B is lower than the threshold second, and the time difference between the two is greater than Xms, then data A can be judged as the root cause; if the time difference between the two is less than Xms, then the root cause is determined based on the power flow direction at that time, the fault location, and other data;

[0047] (f) The power generation controller only sends the fundamental fault information to the display terminal.

[0048] Furthermore, the specific method of step d is:

[0049] (1) Determine whether the fault severity is level 3:

[0050] If yes, shut down the power immediately, the instrument lights up, and then return to step 2

[0051] If no, continue to the next step

[0052] (2) Determine whether the fault severity is level 2:

[0053] If yes, the power is limited and the instrument lights up.

[0054] If no, continue to the next step

[0055] (3) Display terminal displays fault codes and maintenance suggestions

[0056] (4) Determine whether other faults occur within Y seconds:

[0057] If yes, the generator controller determines the fundamental fault

[0058] If no, end the process.

[0059] As another aspect of the present invention, it also relates to a vehicle-mounted high-voltage power generation block diagnostic device, comprising:

[0060] -Motor control unit, used to diagnose motor-related faults;

[0061] -High-voltage distribution box control unit, used to diagnose high-voltage distribution box related faults;

[0062] -Power control unit, used to diagnose power supply and supercapacitor related faults;

[0063] -Generator controller, used to receive and analyze the diagnostic results of each control unit, and execute the final fault judgment and protection measures;

[0064] -Memory, used to store fault-related data;

[0065] -Display terminal, used to display fault information and maintenance suggestions;

[0066] -Mobile cellular communication chip for remote diagnosis and control functions;

[0067] The motor control unit, high-voltage distribution box control unit and power control unit are all connected to the power generation controller through the CAN A network; the power generation controller is connected to the engine controller, body controller and display terminal through the CAN B network.

[0068] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0069] (1) The diagnostic method of a vehicle-mounted high-voltage power generation block of the present invention adopts a two-level diagnosis mode of total and division. The motor control unit, the high-voltage distribution box control unit, the power supply control unit and the power generation controller respectively make preliminary diagnosis of self-generated related faults, and then summarize them to the power generation controller for final judgment, storage and limitation. The four control units make diagnosis at the same time, which is more efficient. The motor control unit, the high-voltage distribution box control unit and the power supply control unit do not need to store and decide the actions after the fault occurs. The hardware configuration requirements for calculation and storage are low, which saves costs.

[0070] (2) The diagnostic method of a vehicle-mounted high-voltage power generation block of the present invention finds the most fundamental fault based on logical calculations, and will not mislead the driver due to multiple fault information caused by one problem, thereby improving the accuracy of diagnosis.

[0071] (3) The diagnostic method of a vehicle-mounted high-voltage power generation block of the present invention can comprehensively diagnose various faults of the power generation components by using multiple control units to improve the comprehensiveness of the diagnostic function coverage.

[0072] (4) The diagnostic method of a vehicle-mounted high-voltage power generation block of the present invention classifies the faults of the power generation block and stores only the data closely related to the fault according to the fault classification, rather than storing all the data, thereby saving storage space.

[0073] (5) The diagnostic method of a vehicle-mounted high-voltage power generation block of the present invention records data for a continuous period of time before and after the occurrence of a fault when a fault occurs. According to the change in data, the preconditions and subsequent impacts of the fault are studied, which is conducive to rapid analysis and problem solving. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 It is a schematic diagram of the structure of the diagnostic device according to an embodiment of the present invention;

[0075] Figure 2 A schematic diagram of a flow chart of an embodiment of the present invention; DETAILED DESCRIPTION

[0076] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0077] Please refer to Figure 1-Figure 2 In the embodiment of the present invention, the vehicle is driven by an engine, and the engine is also connected to a high-voltage motor through a belt or gear. The on-board high-voltage power generation block converts part of the engine's kinetic energy into high-voltage electrical energy for external supply, for example, for cleaning, washing, towing, and other high-voltage equipment other than driving. The diagnostic device and diagnostic method of this embodiment are described as follows:

[0078] 1. The on-board power generation block is mainly composed of a high-voltage motor, a motor control unit, a supercapacitor, a power control unit, a high-voltage distribution box, a high-voltage distribution box control unit, and a power generation controller. The internal information is transmitted via the CAN A communication network, and the motor and the motor control unit have internal communication. The external components of the power generation block related to diagnosis include the engine controller, the body controller, and the display terminal. The external information is transmitted via the CAN B communication network. See the schematic diagram of the on-board power generation block diagnostic system. Figure 1 .

[0079] 2. Motor control unit diagnoses internal faults of the motor and motor control unit;

[0080] 2.1 If the motor control voltage is less than or greater than the threshold range, a motor control power supply voltage fault is reported;

[0081] 2.2 The motor control unit monitors the motor stator temperature and the ambient temperature at the same time. If the motor stator temperature or the temperature difference between the two exceeds the first temperature threshold, a motor overtemperature fault of the first level will be reported; if the stator temperature or the temperature difference exceeds the second temperature threshold, a motor overtemperature fault of the second level will be reported; if the stator temperature or the temperature difference exceeds the third temperature threshold, a motor overtemperature fault of the third level will be reported;

[0082] 2.3 The motor control unit monitors the motor stator temperature and ambient temperature at the same time, and calculates the temperature and temperature change rate according to the motor's operating conditions and time. If it is continuously lower than the normal value, the motor temperature sensor fault is reported;

[0083] 2.4 The motor control unit monitors the temperature of the IGBT (insulated gate bipolar transistor). If the temperature exceeds the first temperature threshold, a first-level IGBT over-temperature fault is reported; if the temperature exceeds the second temperature threshold, a second-level IGBT over-temperature fault is reported; if the temperature exceeds the third temperature threshold, a third-level IGBT over-temperature fault is reported;

[0084] 2.5 The motor control unit monitors the bus voltage signal of the motor control unit. After filtering and calculation, if the bus voltage exceeds the primary voltage threshold, a primary fault of the motor control unit bus overvoltage is reported; if it exceeds the secondary voltage threshold, a secondary fault of the motor control unit bus overvoltage is reported; if it exceeds the third voltage threshold, a third fault of the motor control unit bus overvoltage is reported;

[0085] 2.6 The motor control unit monitors the motor rotor speed. If it exceeds the first-level speed threshold, it will report a first-level motor speed over-high fault; if it exceeds the second-level speed threshold, it will report a second-level motor speed over-high fault; if it exceeds the third-level speed threshold, it will report a third-level motor speed over-high fault;

[0086] 2.7 The motor control unit collects the current signals of each phase of the motor. If the current of one phase exceeds the threshold, a motor phase current overcurrent fault is reported; if the current vector sum is not zero, a current abnormality fault is reported;

[0087] 3 High-voltage distribution box control unit diagnosis High-voltage distribution box and high-voltage distribution box control unit internal fault

[0088] 3.1 If the voltage of the high-voltage distribution box control circuit is less than or greater than the threshold range, a high-voltage distribution box control power supply voltage fault is reported;

[0089] 3.2 The high-voltage distribution box control unit monitors the resistance value between the positive and negative poles of the high-voltage distribution box power supply and the casing. If the resistance value is less than the first-level resistance threshold, a first-level insulation fault of the high-voltage distribution box is reported; if the resistance value is less than the second-level resistance threshold, a second-level insulation fault of the high-voltage distribution box is reported;

[0090] 3.3 The high-voltage distribution box control unit monitors the voltage at the rear end of the load main relay of the high-voltage distribution box. After the load main relay is closed, the voltage is filtered and calculated. If the voltage exceeds the primary voltage threshold, a primary overvoltage fault of the high-voltage distribution box is reported; if the voltage exceeds the secondary voltage threshold, a secondary overvoltage fault of the high-voltage distribution box is reported; if the voltage exceeds the third voltage threshold, a third overvoltage fault of the high-voltage distribution box is reported;

[0091] 3.4 The high-voltage distribution box control unit monitors the voltage between the high-voltage distribution box housing and the vehicle iron wire. If the voltage is greater than the threshold, a ground fault of the high-voltage distribution box is reported;

[0092] 4 Power control unit diagnosis Power control unit and super capacitor internal fault

[0093] 4.1 The power control unit monitors the cell voltage of a single capacitor. If any cell voltage exceeds the first-level cell voltage threshold, a first-level capacitor cell overvoltage fault is reported; if it exceeds the second-level cell voltage threshold, a second-level capacitor cell overvoltage fault is reported; if it exceeds the third-level cell voltage threshold, a third-level capacitor cell overvoltage fault is reported;

[0094] 4.2 The power control unit monitors the total voltage of the supercapacitor bus. After filtering and calculation, if the bus voltage exceeds the first-level total voltage threshold, a first-level overvoltage fault of the high-voltage distribution box bus will be reported; if it exceeds the second-level total voltage threshold, a second-level overvoltage fault of the high-voltage distribution box bus will be reported; if it exceeds the third-level total voltage threshold, a third-level overvoltage fault of the high-voltage distribution box bus will be reported;

[0095] 4.3 The power control unit calculates the sum of the cell voltages of a single capacitor λ=∑u i , according to the λ curve, the threshold is obtained. If the difference between the total voltage V of the supercapacitor bus and λ, i.e. |V-λ|, exceeds the threshold, the supercapacitor bus voltage sensor fault is reported;

[0096] 4.4 The power control unit monitors the temperature of individual capacitors, numbers the temperature of individual capacitors, and calculates the upper and lower limits of the temperature deviation of individual capacitors based on the temperatures of all individual capacitors and the total battery voltage. V-total battery voltage, T i -The temperature of the i-th single capacitor; if the temperature of the j-th single capacitor is T j If the limit is exceeded, the temperature of the jth capacitor is reported as excessive.

[0097] 4.5 The power control unit monitors the temperature of a single capacitor, the total battery voltage and the ambient temperature, and calculates V-total battery voltage, T0-ambient temperature; if the temperature of cell j is T j If the temperature of the jth capacitor cell is higher than the first level threshold T′, a first level fault of over-temperature of the jth capacitor cell is reported; j If the temperature Ti of the jth capacitor cell is higher than the second-level fault threshold of 1.2T', a second-level fault of overtemperature of the jth capacitor cell is reported; if the temperature Ti of the jth capacitor cell is higher than the second-level fault threshold of 1.4T', a third-level fault of overtemperature of the jth capacitor cell is reported;

[0098] 4.6 The power control unit monitors the temperature of the high temperature area of ​​the capacitor pack. If it exceeds the first temperature threshold, a first-level supercapacitor overtemperature fault is reported; if it exceeds the second temperature threshold, a second-level supercapacitor overtemperature fault is reported; if it exceeds the third temperature threshold, a third-level supercapacitor overtemperature fault is reported;

[0099] 4.7 If the power supply control circuit voltage is less than or greater than the threshold range, a high-voltage distribution box control power supply voltage fault is reported;

[0100] 5 The power generation controller diagnoses faults directly related to the power generation controller. The power generation controller stores the faults of the motor control unit, the high-voltage distribution box control unit and the power supply control unit and the data stream related to the faults. When multiple faults occur at the same time, the power generation controller determines the root cause and sends the fault code and lighting information to the display terminal and the body controller. The power generation controller decides the protection mode according to the current fault;

[0101] 5.1 Fault alarms directly related to the generator controller

[0102] 5.1.1 If the communication failure time between the generator controller and the motor control unit exceeds the threshold, a communication loss fault between the generator controller and the motor control unit will be reported;

[0103] 5.1.2 If the communication failure time between the power generation controller and the high-voltage distribution box control unit exceeds the threshold, a communication loss fault between the power generation controller and the high-voltage distribution box control unit will be reported;

[0104] 5.1.3 If the communication failure time between the power generation controller and the power control unit exceeds the threshold, a communication loss fault between the power generation controller and the power control unit will be reported;

[0105] 5.1.4 If the communication between the generator controller and the motor control unit, high-voltage distribution box control unit, and power control unit fails at the same time, a CAN network A fault will be reported;

[0106] 5.1.5 If the communication failure time between the generator controller and the engine controller exceeds the threshold, a communication loss fault between the generator controller and the engine controller will be reported;

[0107] 5.1.6 If the communication failure time between the generator controller and the body controller exceeds the threshold, a communication loss fault between the generator controller and the body controller will be reported;

[0108] 5.1.7 If the communication failure time between the power generation controller and the display terminal exceeds the threshold, a communication loss fault between the power generation controller and the display terminal will be reported;

[0109] 5.1.8 If the generator controller fails to communicate with the engine controller, body controller and display terminal at the same time, a CAN network B fault will be reported;

[0110] 5.1.9 The power generation controller calculates according to the key signal, engine status, and power generation system switch signal, and sends the motor main relay, motor pre-charge relay, load main relay, and load pre-charge relay control instructions to the high-voltage distribution box control unit. If the status of a certain relay sent by the high-voltage distribution box control unit is inconsistent with the corresponding control instruction, the uncontrolled fault of the relay will be reported;

[0111] 5.1.10 The power generation controller calculates according to the key signal, engine status, and power generation system switch signal, and sends the power main relay control instruction to the power control unit, receives the status of the power main relay sent by the power control unit, and reports the power system main relay uncontrolled fault if the relay status is inconsistent with the control instruction;

[0112] 5.1.11 The generator controller calculates the fan speed according to the motor temperature, the motor control unit temperature and the high-voltage distribution box temperature, sends the fan PWM control command to the cooling system control unit, receives the actual fan speed feedback sent by the cooling system control unit, and performs closed-loop control with the fan speed as the target. If the difference between the actual fan speed and the calculated fan speed exceeds the threshold and the duration exceeds the threshold, a cooling fan fault is reported;

[0113] 5.1.12 The generator controller calculates the water pump outlet pressure according to the motor temperature, the motor control unit temperature and the high-voltage distribution box temperature, and sends the water pump PWM control instruction to the cooling system control unit, receives the water pump outlet pressure sent by the cooling system control unit, and performs closed-loop control with pressure as the target. If the difference between the actual pressure and the calculated pressure exceeds the threshold and the duration exceeds the threshold, a water pump fault is reported;

[0114] 5.1.13 The generator controller receives the engine speed from the engine controller and the actual motor speed from the motor control unit, and calculates the motor theoretical speed based on the engine speed, the transmission ratio between the engine and the motor, and the slip coefficient. The slip coefficient is calculated based on the transmission mode and the motor power. If the difference between the motor theoretical speed and the actual motor speed exceeds the threshold and the duration exceeds the threshold, the motor speed error is reported;

[0115] 5.1.14 The generator controller receives the engine speed and output torque from the engine controller, and receives the vehicle speed and parking status signals from the body controller to calculate the theoretical maximum power of the motor. If the actual power of the motor generated by the motor control unit exceeds the theoretical maximum power of the motor, an abnormal motor power fault is reported;

[0116] 5.2 When the motor control unit, high-voltage distribution box control unit and power supply control unit detect a fault, they will send it to the power generation controller, which will convert the received fault and its own fault into the corresponding fault code;

[0117] 5.3 The power generation controller has a large capacity random access memory RAM, a large capacity electrically erasable programmable read-only memory EEPROM and a flash memory FLASH. RAM is used for short-term storage, and the storage content is cleared when the power is turned off. EEPROM can be stored for a long time, and the storage content is not cleared when the power is turned off. The diagnostic calculation logic and threshold are stored in FLASH.

[0118] When the motor control unit, high-voltage distribution box control unit and power supply control unit report a fault, they send the fault information to the power generation controller. At the same time, the power generation controller periodically receives the real-time data streams from the motor control unit, high-voltage distribution box control unit and power supply control unit, including voltage, current, temperature, speed, status and other information; the power generation controller also periodically receives the real-time data streams related to the power generation system from the engine controller and body controller, including key position, engine speed, torque, vehicle speed, parking status and other information. The data stream is used to analyze the cause of the fault. It is not necessary to analyze all the data for a certain fault. In order to save storage space, the faults are grouped by type. The same data needs to be stored for the same group of faults, among which the key data such as engine speed, key status, vehicle speed, time and so on are the data that need to be saved for each fault.

[0119] The power generation controller saves the received real-time data stream in RAM, taking the current time as zero as T, the diagnostic system communication cycle as Xms, Xms before zero as T-1, 2Xms before zero as T-2, 3Xms before zero as T-3, and so on, setting and recording N cycle data, at the current moment, the RAM saves the data streams of T, T-1, T-2...T-N+1, as time continues to advance Xms to T+1, the RAM saves the data stream of T+1, erases the data of T-N+1, and the RAM still stores N cycle data. If the power generation controller receives or detects a fault at T*, and determines the fault group, then the data related to each cycle from T*-N+1 to T* and the group is saved to EEPROM, and the data related to the group in the last three cycles, namely T*+1, T*+2, and T*+3, are also saved to EEPROM. After turning off the power, the information saved in the EEPROM still exists. The EEPROM can store up to M faults and data information related to the faults. If the storage limit is reached, the original fault will be erased and the new fault will be stored when a new fault occurs. The faults with lower severity will be erased first, and then the faults with the earliest occurrence time will be erased.

[0120] 5.4 The power generation controller divides the fault into three levels according to the severity of the damage to the power generation system, vehicle and operator, with level 1 being the mildest and level 3 being the most serious. If the severity is level 1, no restrictions will be imposed; if the severity is level 2, a power limit command and limit value will be sent to the motor control unit, and the limit value is determined by the vehicle speed, motor speed, and bus voltage of the motor control unit (calculation of limit power: P-external characteristic power obtained from motor speed; v-reference speed; v′-actual speed, if the actual speed is lower than the reference speed, then v′=v; V-reference voltage; V′-actual voltage) If the severity is level three, emergency high voltage power will be cut off; the system will automatically supply high voltage according to normal procedures and send power limitation commands and limits to the motor control unit after a period of time based on fault and data analysis, which will not endanger personnel. If level three fault occurs again, high voltage power will no longer be automatically supplied; but the operator can still manually supply high voltage to the power generation module.

[0121] 5.5 The generator controller sends the fault code and severity to the display terminal, which queries the maintenance suggestion based on the fault code and displays the fault code, severity and maintenance suggestion on the screen. If multiple faults are reported in a short period of time, the generator controller will determine which one is the fundamental fault based on the fault information and data information stored in the EEPROM, and only send the fundamental fault code to the display terminal. If there is a secondary or tertiary fault at present, the generator controller will light up the generator system fault light on the instrument by sending information to the body controller.

[0122] 5.6 In case of a level 1 fault, if the fault is cured, the sending of light and fault information to the vehicle body controller and display terminal will stop; in case of a level 2 fault, if the fault is cured and the power generation block works normally for a certain period of time or the power generation block is restarted, the sending of light and fault information to the vehicle body controller and display terminal will stop and the power restriction will be lifted; in case of a level 3 fault, if the fault is cured and the power generation block is restarted, the sending of light and fault information to the vehicle body controller and display terminal will stop and the shutdown and power restriction will be lifted, allowing the power generation block to generate electricity normally.

[0123] 5.7 There is a mobile cellular communication chip in the power generation controller. The host computer can remotely read and erase the faults and data in the EEPROM, and can also remotely release the power and shutdown restrictions.

[0124] In one embodiment, the diagnostic system communication cycle is set to 50ms, and the on-board high-voltage block works normally and outputs electric energy to the outside. The power generation controller detects an uncontrolled fault of the load main relay at 13h21′15.75″, and receives a second-level overvoltage fault of the motor control unit bus voltage reported by the motor control unit, a second-level overvoltage fault of the high-voltage distribution box reported by the high-voltage distribution box control unit, and a second-level overvoltage fault of the supercapacitor bus reported by the power supply control unit at 13h21′15.85″.

[0125] After logical calculation, the power generation controller determines that the uncontrolled load main relay fault is the fundamental fault, which is a secondary serious fault. Other faults are caused by uncontrolled relays and are associated faults. The power generation controller only sends the uncontrolled load main relay fault code and severity to the display terminal. The display terminal displays the fault code, secondary serious fault and maintenance suggestions. The power generation controller sends a request to the body controller to light up the power generation block fault light on the instrument. The power generation controller sends a power limit instruction and power limit value to the motor control unit.

[0126] The generator controller saves the load main relay uncontrolled fault code and the data related to the fault at 13h21′15.30″, 15.35″, 15.40″, 15.45″, 15.50″, 15.55″, 15.60″, 15.65″, 15.70″, 15.75″, 15.80″, 15.85″, 15.90″ in the EEPROM, and the motor control unit bus voltage overvoltage The level fault code, high-voltage distribution box overvoltage level 2 fault code and supercapacitor bus overvoltage level 2 fault code and the data related to these faults at 13h21′15.40″, 15.45″, 15.50″, 15.55″, 15.60″, 15.65″, 15.70″, 15.75″, 15.80″, 15.85″, 15.90″, 15.95″, 16.00″ are also stored in the EEPROM. The host computer can remotely communicate with the power generation controller and read the fault code and data information through the protocol.

[0127] The technical solution of the present invention has the following advantages:

[0128] 1 Each subcomponent in the on-board high-voltage power generation block makes a preliminary diagnosis of its own fault, and then the power generation controller handles all faults in a unified manner, forming a two-level diagnosis mode to improve the timeliness and accuracy of fault alarms;

[0129] 2When a fault occurs, the power generation controller records the data flow before and after the fault, and can provide it to the host computer at any time to help thoroughly analyze and solve the problem;

[0130] 3. The power generation controller collects and analyzes all faults and data, assigns a fault code to each fault, and divides the severity level. The fault code, severity level, and maintenance suggestions are displayed on the display terminal, and a protection response is made.

[0131] 4If a fault causes multiple faults to be reported by different components, the power generation controller will analyze and determine the fundamental fault, and only display the fundamental fault on the display terminal to improve accuracy;

[0132] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A diagnostic method for a vehicle-mounted high-voltage power generation module, characterized in that , including the following steps: (a) The motor control unit, high-voltage distribution box control unit, power supply control unit and power generation controller respectively perform preliminary diagnosis on the faults and fault levels related to themselves; (b) sending preliminary diagnosis result data with fault level information to the power generation controller; (c) The power generation controller stores the preliminary diagnosis result data and the real-time data of the motor control unit, the high-voltage distribution box control unit, and the power supply control unit received periodically in the memory, and updates and stores the data according to whether the power generation block has a fault; (d) Classify the severity of the fault according to the degree of fault hazard, and convert the received faults and its own faults into corresponding fault codes; the power generation controller summarizes and analyzes the fault codes and severity to the display terminal; Determine the final fault diagnosis result and implement corresponding protection measures.

2. The diagnostic method for a vehicle-mounted high-voltage power generation block according to claim 1 is characterized in that In step (a), the preliminary diagnosis items of the motor control unit include: -Motor control voltage; -Motor stator temperature; - IGBT temperature; - Motor control unit bus voltage; -Motor rotor speed; - Motor phase currents.

3. The diagnostic method for a vehicle-mounted high-voltage power generation block according to claim 1 is characterized in that In step (a), the preliminary diagnosis items of the high-voltage distribution box control unit include: -High voltage distribution box control circuit voltage; -Insulation status of high voltage distribution box; -The voltage at the rear end of the main relay of the high-voltage distribution box load; -Grounding status of high voltage distribution box.

4. The diagnostic method for a vehicle-mounted high-voltage power generation block according to claim 1 is characterized in that In step (a), the preliminary diagnosis items of the power control unit include: -Supercapacitor cell voltage; -Total voltage of supercapacitor busbar; -Supercapacitor bus voltage sensor status; - Individual capacitor temperature; - Individual capacitor temperature, total battery voltage and ambient temperature -Capacitor package high temperature area temperature; -Power supply control circuit voltage; The single capacitor temperature diagnosis method is as follows: number the temperature of the single capacitor, and calculate the upper and lower limits of the temperature deviation of the single capacitor according to the temperature of all single capacitors and the total voltage of the battery. V-total battery voltage, T i -The temperature of the i-th single capacitor; if the temperature of the j-th single capacitor is T j If the limit is exceeded, the temperature of the jth capacitor is reported as excessive. Among them, the temperature of a single capacitor, the total battery voltage and the ambient temperature, the diagnosis method is: calculation V-total battery voltage, T0-ambient temperature; if the temperature of cell j is T j If the temperature of the jth capacitor cell is higher than the first level threshold value T′, a first level fault of over-temperature of the jth capacitor cell is reported; j If the temperature Ti of the jth capacitor cell is higher than the second-level fault threshold of 1.2T′, a second-level fault of excessive temperature change of the jth capacitor cell will be reported; if the temperature Ti of the jth capacitor cell is higher than the second-level fault threshold of 1.4T′, a third-level fault of excessive temperature change of the jth capacitor cell will be reported.

5. The diagnostic method for a vehicle-mounted high-voltage power generation block according to claim 1 is characterized in that In step (a), the power generation controller also performs the following diagnosis: -Communication status with each control unit; -Communication status with external controllers; -Relay control status; -Cooling system status; -Motor speed consistency; - Reasonableness of motor power.

6. The diagnostic method for a vehicle-mounted high-voltage power generation block according to claim 1 is characterized in that ,The step (c) updates and saves the data according to whether the power generation block has a fault. The specific method is as follows: ,(1) the power generation controller stores the data in the RAM ,(2) judging whether a fault has occurred. If there is no fault, the data N cycles ago in the RAM are deleted. If so, the next step is continued; The specific method of deleting the data N cycles ago in RAM is as follows: the power generation controller saves the received real-time data stream in RAM, takes the current time as zero point as time T, the diagnostic system communication cycle is Xms, Xms before zero point is time T-1, 2Xms before zero point is time T-2, 3Xms before zero point is time T-3, and so on. Set to record N cycle data. At the current moment, the RAM saves the data streams of time T, T-1, T-2...T-N+1. As time continues to advance Xms to time T+1, RAM saves the data stream of time T+1, erases the data of time T-N+1, and there are still N cycles in RAM. period data; if the power generation controller receives or detects a fault at time T* and determines the fault group, the data related to the group in each cycle from T*-N+1 to T* is saved to the EEPROM, and the data related to the group in the last three cycles, namely T*+1, T*+2, and T*+3, is also saved to the EEPROM; the information saved in the EEPROM still exists after the power is turned off. The EEPROM can store up to M faults and data information related to the faults. If the storage reaches the upper limit, the original fault will be erased and the new fault will be stored when a new fault occurs. The faults with lower severity will be erased first, and then the faults with the earliest occurrence time will be erased.

7. The diagnostic method for a vehicle-mounted high-voltage power generation block according to claim 6 is characterized in that In step (a), the faults are divided into three levels, and the power generation controller performs different protection measures according to the fault level: There are no restrictions for level 1 failures; Second level fault sends power limit command and limit value; For level 3 faults, emergency high voltage power reduction operation shall be performed; Among them, the limit value sent by the secondary fault is determined by the vehicle speed, motor speed, and bus voltage of the motor control unit: Calculate the limit power: P-external characteristic power obtained from the motor speed; v-reference vehicle speed; v′-actual vehicle speed. If the actual vehicle speed is less than the reference vehicle speed, v′=v; V-reference voltage; V′-actual voltage).

8. The diagnostic method for a vehicle-mounted high-voltage power generation block according to claim 1 is characterized in that , further comprising the following steps: (e) When multiple faults occur in a short period of time, the power generation controller determines the root cause through analysis; the determination principle is: determine the initial time when different data are lower than the threshold. If data A is lower than the threshold first, and data B is lower than the threshold second, and the time difference between the two is greater than Xms, then data A can be judged as the root cause; if the time difference between the two is less than Xms, then the root cause is determined based on the power flow direction at that time, the fault location, and other data; (f) The power generation controller only sends the fundamental fault information to the display terminal.

9. The diagnostic method for a vehicle-mounted high-voltage power generation block according to claim 1 is characterized in that , the specific method of step d is: (1) Determine whether the fault severity is level 3: If yes, emergency power off, the instrument lights up, and then return to step 2 If no, continue to the next step (2) Determine whether the fault severity is level 2: If yes, the power is limited and the instrument lights up. If no, continue to the next step (3) Display terminal displays fault codes and maintenance suggestions (4) Determine whether other faults occur within Y seconds: If yes, the generator controller determines the fundamental fault If no, end the process.

10. A vehicle-mounted high-voltage power generation block diagnostic device for implementing the diagnostic method described in any one of claims 1 to 9, characterized in that ,include: -Motor control unit, used to diagnose motor-related faults; -High-voltage distribution box control unit, used to diagnose high-voltage distribution box related faults; -Power control unit, used to diagnose power supply and supercapacitor related faults; -Generator controller, used to receive and analyze the diagnostic results of each control unit and perform final fault judgment and protection measures; -Memory, used to store fault-related data; -Display terminal, used to display fault information and maintenance suggestions; -Mobile cellular communication chip for remote diagnosis and control functions; The motor control unit, high-voltage distribution box control unit and power control unit are all connected to the power generation controller through the CAN A network; the power generation controller is connected to the engine controller, body controller and display terminal through the CAN B network.

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