A PTC control system and method for a new energy vehicle

Abstract

The application discloses a PTC control system and method of a new energy vehicle, and belongs to the field of automobile air conditioners. The system comprises a central control large screen, a battery management system BMS, a vehicle controller, a high-voltage control module HVCM, a PTC controller, a PTC temperature sensor and a PTC, wherein the vehicle controller is connected with the central control large screen, the BMS, the HVCM and the PTC controller respectively; the PTC controller is connected with the PTC temperature sensor and the PTC respectively; and the HVCM is connected with the BMS. The application realizes reasonable distribution of PTC power when the passenger cabin and the battery pack have heating demand.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of automobile air conditioners, and particularly relates to a PTC control system and method for a new energy automobile. BACKGROUND

[0002] Nowadays, with the increasingly serious environmental pollution and global warming, in order to save energy and protect the environment, the development of new energy vehicles is timely, but in cold winter, it is particularly important for the driver and passengers to maintain a comfortable temperature in the vehicle.

[0003] If the temperature of the power battery pack cannot be controlled in a reasonable range during the driving process of the vehicle, the activity of the battery will be affected, and even the service life of the battery will be affected. Similarly, if the passenger cabin temperature is not reasonable when the temperature is low, the driving comfort will be affected, and even safety hazards will be caused.

[0004] As an important component of the automobile air conditioner heating, the control of PTC (automobile heater) is crucial, so as to maintain the passenger cabin temperature and the power battery pack temperature in a reasonable and safe range.

[0005] However, the control algorithm of the PTC currently used by the new energy automobile is relatively single, and the heating strategy during charging and the heating demand of the battery are not fully considered. The PTC power distribution is uneven and the power consumption is rapid, so as to cause the vehicle to have a large discount in the endurance in severe cold weather. SUMMARY

[0006] The present application aims to overcome the shortcomings of the prior art, and proposes a PTC control system and method for a new energy automobile, so as to achieve the following purposes: to realize the reasonable distribution of the PTC power when the passenger cabin and the battery pack have heating demand.

[0007] In order to achieve the above object, the technical scheme adopted by the present application is as follows: a PTC control system of a new energy vehicle, the system comprising a central control large screen, a battery management system (BMS), a vehicle controller, a high voltage control module (HVCM), a PTC controller, a PTC temperature sensor, and a PTC, wherein the vehicle controller is connected with the central control large screen, the BMS, the HVCM, and the PTC controller respectively; the PTC controller is connected with the PTC temperature sensor and the PTC respectively; the HVCM is connected with the BMS; the central control large screen panel is provided with a panel temperature gear knob, a panel air volume gear knob, a defrosting and defogging button, and a PTC switch, and their respective state signals are sent to the vehicle controller after being collected by the central control large screen; the BMS is used for monitoring the battery state and sending a battery heating request signal to the vehicle controller; the HVCM is used for monitoring the vehicle high voltage state and feeding back a battery charging state signal to the vehicle controller; the PTC temperature sensor is used for collecting the PTC outlet temperature and sending it to the vehicle controller through the PTC controller; the vehicle controller is used for processing the received signals and outputting a PTC control signal to the PTC controller to control the output power of the PTC; the PTC controller is further used for monitoring the actual output power of the PTC, diagnosing the PTC, and obtaining a fault level, and the monitoring and diagnosis results are fed back to the vehicle controller.

[0008] Meanwhile, according to the above system, the present application further proposes a PTC control method of a new energy vehicle, the method comprising the following steps:

[0009] Step S1: the vehicle controller collects signals during the working of system components, including a PTC switch signal, a panel temperature knob gear signal, an air volume knob signal, a defrosting and defogging button signal, a PTC temperature sensor signal, a battery state, a vehicle high voltage state, a BMS battery heating request signal, an HVCM battery charging state signal, a PTC actual output power, and a PTC fault level;

[0010] Step S2: the vehicle controller outputs a PTC control signal to the PTC controller to control the output power of the PTC after processing the collected signals.

[0011] Preferably, the processing of the received signals by the vehicle controller comprises judging whether to send a PTC enable request, wherein the PTC enable request is triggered only when the following conditions are met simultaneously:

[0012] (1) the power-on mode is in a non-OFF state, and the main positive and main negative relays are both closed; or in the battery charging state, the high voltage control module feeds back a battery pack charging state as: charging and heating state, or pure heating state;

[0013] (2) The PTC heater failure level does not exceed the preset level;

[0014] (3) The vehicle controller and the PTC controller communicate normally;

[0015] (4) The panel temperature knob is within the preset range, and the panel air volume knob is in the active state;

[0016] (5) The PTC switch is in the on state; or the BMS sends a battery heating request in the non-slow charging mode; or the BMS sends a battery heating request in the slow charging mode and the charging state is not in the initialization and pending state;

[0017] (6) No PTC failure signal is received.

[0018] Preferably, after receiving the PTC control signal of the vehicle controller, the PTC controller drives the working power of the PTC to increase or decrease at a rate of 2kw / s, and the power of the PTC is immediately reset to 0 without PTC enable request.

[0019] Preferably, after the PTC enable trigger, the processing of the signals received by the vehicle controller includes calculating the total bus output PTC power P 总线 , wherein:

[0020] (1) When the vehicle is in a non-charging state,

[0021] P Req = P 面板 + P BMS

[0022] P 总线 = Min(P BMSLimit , P Req )

[0023] wherein P Req represents the sum of the panel PTC request power P 面板 of the central control large screen and the battery pack heating PTC request power P BMS of the BMS; P BMSLimit represents the maximum available power of the battery pack allocated to the PTC;

[0024] (2) When the vehicle is in a charging state and the main positive and main negative relays are closed,

[0025] P 总线 = Min(P HVCM + P BMSLimit , P Req )

[0026] When the vehicle is in a charging state and the main positive relay is open, ​

[0027] P 总线 = Min(P HVCM , P Req );

[0028] wherein P HVCM represents the PTC power allowed by the high-voltage control module for the request of the vehicle controller;

[0029] Preferably, for the P Req , when only the panel PTC heating request of the central control large screen exists, it is obvious that P Req = P 面板 ; when only the battery pack heating request of the BMS exists, it is obvious that P Req = P BMS , wherein:

[0030] If the vehicle is in a Ready state, i.e., a driving ready state, P BMS = 0;

[0031] If the main positive and main negative relays are closed after the charging gun is inserted but the BMS does not allow charging, P BMS = 3KW;

[0032] If the main positive and main negative relays are closed after the charging gun is inserted and the BMS allows charging, P BMS is obtained according to the difference between the target heating temperature of the battery pack and the water inlet temperature of the battery pack.

[0033] Preferably, for the P Req , only when the P Req is greater than a preset power threshold value, the P Req is output, otherwise, the output P Req = 0.

[0034] Preferably, after the PTC is enabled, the processing of the signals received by the vehicle controller includes limiting the panel PTC request power P 面板 of the central control large screen, wherein:

[0035] Limitation case 1: when no defrosting and defogging button is pressed and no battery heating request is detected, the panel PTC request power P 面板 of the central control large screen is limited, i.e.:

[0036] If T OutTemp ≥ 55℃, P Max = 1.5KW;

[0037] If T OutTemp ≤ 45℃, P Max = 8.5KW;

[0038] If 45℃ < TOutTemp <55℃, then according to T OutTemp Look up table for P 面板 Limit;

[0039] Wherein, T OutTemp represents the PTC outlet temperature; P Max represents the maximum allowable panel PTC request power;

[0040] Limit case 2: according to the panel temperature knob and the air volume knob, look up table, limit P 面板 ;

[0041] The final output of the panel PTC request power P 面板 of the central control large screen is the minimum value of P 面板 under the limit case 1 and 2.

[0042] Preferably, after the PTC is enabled, the processing of the received signal by the vehicle controller includes PTC fault judgment, wherein:

[0043] When the vehicle is in a non-charging and non-high-voltage state, no PTC fault is judged, and otherwise:

[0044] (1) When the actual output power of the PTC and the bus output PTC power P 总线 error exceeds the preset error threshold, the enable signal of the PTC is delayed to be closed, and the PTC fault is judged and recorded;

[0045] (2) After the PTC is enabled, if it is detected that the PTC has not started working within a preset time, the PTC enablement fault is judged and recorded.

[0046] Preferably, once the PTC fault occurs, the vehicle keeps the fault record in the corresponding working cycle and cannot be automatically cleared until the fault is manually reset after troubleshooting.

[0047] The technical effect of the present application is that the opening, closing and output power safety limit of the PTC are comprehensively considered, the power distribution of the PTC when the central control panel and the battery pack work independently and simultaneously can be accurately judged, the request can be quickly responded and heated, the passenger cabin temperature and the power battery pack temperature can be maintained in a comfortable and safe range, the production cost of the vehicle is low, and the heating effect is good. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 It is a PTC control system structure diagram of a new energy vehicle. DETAILED DESCRIPTION

[0049] The following is a detailed description of the specific embodiments of the present invention by referring to the accompanying drawings. The purpose is to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention and to facilitate its implementation. To make the technical solution of the present invention more clear, the present invention is explained through the following examples.

[0050] This embodiment provides a PTC control system for new energy vehicles, such as Figure 1 As shown, the system includes a central control screen, a battery management system (BMS), a vehicle control unit (VCU), a high-voltage control module (HVCM), a PTC controller, a PTC temperature sensor, and a PTC. The vehicle control unit is connected to the central control screen, the BMS, the HVCM, and the PTC controller, respectively, all using a CAN bus. The CAN bus has a simple layout, ensuring data transmission speed and stability while reducing costs. The PTC controller is connected to the PTC temperature sensor and PTC, respectively; the HVCM is connected to the BMS. In this embodiment, the PTC controller uses a microcontroller (MCU), which has the advantages of high integration and low cost.

[0051] In this embodiment, the central control large screen panel is equipped with a panel temperature gear knob, a panel air volume gear knob, a defrost and defogger button, and a PTC switch. Their respective status signals are collected by the central control large screen and sent to the vehicle controller; the BMS is used to monitor the battery status (battery voltage, current, temperature, charge and discharge status, etc.) and send a battery heating request signal to the vehicle controller, wherein the battery status can also be synchronized to the HVCM; the HVCM is used to monitor the vehicle high voltage status and at the same time feedback the battery charging status signal to the vehicle controller; the PTC temperature sensor is used to collect the PTC water outlet temperature and send it to the vehicle controller through the PTC controller; the vehicle controller is used to process the received signal and output a PTC control signal to the PTC controller to control the output power of the PTC; the PTC controller is also used to monitor the actual output power of the PTC, as well as to diagnose the PTC and obtain the fault level, and the monitoring and diagnosis results are fed back to the vehicle controller.

[0052] At the same time, based on the above-mentioned PTC control system of a new energy vehicle, this embodiment also proposes a PTC control method for a new energy vehicle, which includes the following steps:

[0053] Step S1, the vehicle controller collects signals of system components during operation, including PTC switch signal, panel temperature knob gear signal, air volume knob signal, defrosting and defogging button signal, PTC temperature sensor signal, battery state, vehicle high voltage state, battery heating request signal of BMS, battery charging state signal of HVCM, PTC actual output power, PTC fault level, etc.

[0054] Step S2, the vehicle controller outputs PTC control signal to the PTC controller to control the output power of the PTC according to the processing of the collected signals.

[0055] Specifically, the processing of the received signals by the vehicle controller of the embodiment includes determining whether to send a PTC enable request, wherein the PTC enable request is triggered when the following conditions are met simultaneously:

[0056] (1) The power-on mode is in a non-OFF state, and the main positive and main negative relays are both closed (the electrical system of the vehicle has been activated, and the circuit for supplying power to the PTC has formed a path); or in the battery charging state, the high voltage control module feedback battery pack charging state is: charging and heating state, or pure heating state (temperature plays an important role when the battery is charging, especially at low temperature, the battery needs to be heated to ensure charging efficiency, at this time, the PTC can be powered by external charging equipment);

[0057] (2) The PTC heater fault level does not exceed the preset level, to ensure that the PTC itself is in a relatively good working state (the preset level of the embodiment is level 2, which can be flexibly set according to actual conditions during implementation, and this does not limit the present application);

[0058] (3) The vehicle controller and the PTC controller are in normal communication to ensure that the PTC enable signal is sent to the PTC controller in time;

[0059] (4) The panel temperature knob gear is within the preset gear range (9-16 gears in the embodiment), and the panel air volume knob is in the active state, indicating that the user expects to heat the vehicle cabin through the PTC to raise the temperature, and the air circulation system is also in the open cooperation state;

[0060] (5) The PTC switch is in the open state (the most direct passenger cabin heating request); or the BMS sends a battery heating request in the non-slow charging mode (meaning that the battery needs to be heated to maintain performance, ensure charging efficiency, etc.); or the BMS sends a battery heating request in the slow charging mode and the charging state is not in the initialization and pending state (meaning that the battery indeed has an actual demand for heating during slow charging, and the charging has passed the initialization and other unstable stages);

[0061] (6) No PTC fault signal is received (when PTC fails, PTC enable cannot be triggered, thus ensuring system safety).

[0062] In this embodiment, after receiving the PTC control signal from the vehicle controller, the PTC controller drives the working power of the PTC to increase or decrease at a rate of 2kw / s, which is a smooth adjustment method to avoid the instantaneous impact on the system caused by too fast adjustment, and at the same time, it can also make the PTC more accurately reach the required working power. After there is no PTC enable request, the power of the PTC is immediately reset to 0, thus reducing energy consumption.

[0063] After the PTC enable is triggered, the vehicle controller of this embodiment processes the received signals, including calculating the total bus output PTC power P 总线 , of the vehicle controller

[0064] (1) When the vehicle is in a non-charging state,

[0065] P Req = P 面板 + P BMS ;

[0066] P 总线 = Min(P BMSLimit , P Req )

[0067] Where Min represents the minimum value; P Req represents the panel PTC request power P 面板 of the central large screen and the battery pack heating PTC request power P BMS of the BMS; P BMSLimit represents the maximum available power of the battery pack allocated to the PTC. In a non-charging state, the high-voltage system of the vehicle is mainly used for the normal operation of the equipment (including PTC) in the vehicle, at this time, the bus output PTC power is mainly set according to the actual demand of the vehicle, especially the panel PTC request of the passenger cabin through the central large screen and the battery heating request of the BMS.

[0068] 2) When the vehicle is in a charging state and the main positive and negative relays are closed,

[0069] P 总线 = Min(P HVCM + P BMSLimit , P Req );

[0070] When the vehicle is in a charging state and the main positive relay is open,

[0071] P 总线 = Min(PHVCM , P Req );

[0072] Among them, P HVCM Indicates the PTC power that the high voltage control module allows the vehicle controller to request. When the vehicle is in charging state and the main positive relay is disconnected, the vehicle's high voltage electrical equipment cannot work, but considering the temperature regulation of the battery during charging, the vehicle controller can enable battery pack heating according to the battery charging status feedback from the HVCM. When the vehicle is in charging state and the main positive and negative relays are closed, it means that the main path of the vehicle's high voltage system is connected. Considering the need for heating the battery pack during low temperature charging, there may also be other needs such as temperature regulation in the vehicle, so there will also be P Req .

[0073] For the P Req , when only the central control screen panel PTC heating request, obviously there is P Req =P 面板 When there is only a BMS battery pack heating request, there is obviously a P Req =P BMS ,in:

[0074] If the vehicle is in the Ready state, that is, ready to drive, then P BMS = 0. At this point, the vehicle has completed all preparations, and the battery temperature is within the appropriate range, so no additional heating is required to maintain battery performance.

[0075] If the main positive and negative relays are closed after the charging gun is inserted but the BMS does not allow charging, then P BMS =3KW. The main positive and negative relays are closed, indicating that the vehicle's high voltage system is powered, but the BMS does not allow charging, indicating that the battery status may not meet the charging requirements. At this time, set P BMS =3KW, which can maintain the battery pack in a relatively suitable temperature environment to avoid the inability to charge due to temperature factors. At the same time, the suitable temperature also helps to protect the battery performance.

[0076] If the main positive and negative relays are closed after the charging gun is inserted and the BMS allows charging, the P value is obtained by looking up the table based on the difference between the target heating temperature of the battery pack and the water inlet temperature of the battery pack. BMS The specific table was obtained through a large number of experimental tests in advance, and the following rules are followed: a large difference indicates that the battery temperature is low and a higher heating power is required to quickly raise the temperature; a small difference indicates that the battery temperature is close to the target temperature and only a lower heating power is required to reach the target temperature.

[0077] In this embodiment, for the P Req , only the P Reqgreater than a preset power threshold (the power threshold of the embodiment is set to 0.8kw, which can be flexibly set according to actual conditions), the P Req is output, otherwise, the output P Req =0. When the PTC power is lower than 0.8kW, the useful heat generated is very small, but it will still consume a certain amount of electric energy for maintaining its working state, from the perspective of energy utilization efficiency, the energy waste in this low-power working state is uneconomical.

[0078] In addition, after the PTC is enabled, the processing of the signals received by the vehicle controller of the embodiment also includes limiting the panel PTC request power P 面板 of the central control large screen, so as to fully respect the user's will and ensure system safety, wherein:

[0079] Limiting condition 1: when no defrosting and defogging button is pressed and no battery heating request is detected, the panel PTC request power P 面板 of the central control large screen is limited, that is:

[0080] If T OutTemp ≥55℃, then P Max =1.5KW;

[0081] If T OutTemp ≤45℃, then P Max =8.5KW;

[0082] If 45℃<T OutTemp <55℃, then the P 面板 is limited according to T OutTemp ;

[0083] Wherein, T OutTemp represents the PTC outlet temperature; P Max represents the maximum allowed panel PTC request power.

[0084] T OutTemp ≥55℃ indicates that the PTC has generated enough heat, and running at a higher power may cause the system to overheat, so the power is limited. T OutTemp ≤45℃ indicates that the PTC needs more heat to reach the appropriate working temperature, but in order to avoid the system temperature rising sharply to cause safety hazards due to excessive power, and the waste of resources caused by excessive power, the power is limited. In the interval of 45℃<T OutTemp <55℃, different temperatures may correspond to different optimal powers, in order to achieve higher working efficiency, the power is limited, and the table is obtained by pre-calibration according to a large amount of experimental data.

[0085] Limitation case 2: According to the panel temperature knob gear and the air volume knob gear, a table (obtained by pre-labeling a large amount of experimental data) is looked up to limit P 面板 The panel temperature knob gear and the air volume knob gear represent the subjective will of the user, and P 面板 is limited according to the selection of the user.

[0086] The final output panel PTC request power P 面板 of the central control large screen is the minimum value of P 面板 under the above-mentioned limitation cases 1 and 2, so as to avoid P 面板 being too high to cause damage to the system and unnecessary waste of energy, and to ensure that P 总线 just meets the actual demand, whether it is the demand of the user for the temperature in the vehicle or the safety and stable operation demand of the system itself.

[0087] In the embodiment, after the PTC enabling trigger, the processing of the received signals by the vehicle controller further includes PTC fault judgment, wherein:

[0088] When the vehicle is in a non-charging and non-high-voltage state, no PTC fault is judged, at this time, the vehicle electrical system may be in a relatively low-power or standby state, the PTC has no power supply activation, so the fault of the PTC will not have a substantial impact on the overall operation of the vehicle, so the judgment of its fault is temporarily ignored to reduce unnecessary false alarms and occupation of system resources.

[0089] In addition:

[0090] (1) When the actual output power of the PTC and the bus output PTC power P 总线 exceeds the preset error threshold, the enabling signal of the PTC is delayed to be closed, and the PTC fault is judged and recorded;

[0091] (2) After the PTC enabling trigger, if it is detected that the PTC has not started working within a preset time, the PTC enabling fault is judged and recorded.

[0092] It should be noted that once the PTC fault occurs, the vehicle keeps the fault record in the corresponding working cycle and cannot be automatically cleared until the fault is manually reset after troubleshooting.

[0093] The present application comprehensively considers the opening, closing and safe limitation of the output power of the PTC, can accurately judge the power distribution of the PTC when the central control panel and the battery pack work independently and simultaneously, can quickly respond to the request and heat, so that the passenger cabin temperature and the power battery pack temperature are maintained in a comfortable and safe range, the production cost of the vehicle is low, and the heating effect is good.

[0094] The application is described above with reference to the drawings. It is obvious that the specific implementation of the application is not limited to the above-mentioned manner. As long as various non-essential improvements are made by using the method concept and technical solutions of the application, or the above-mentioned concept and technical solutions of the application are directly applied to other occasions without improvement, they are all within the protection scope of the application.

Claims

1. A control method for a PTC control system of a new energy vehicle, characterized by: The system includes a central control screen, a battery management system BMS, a vehicle controller, a high-voltage control module HVCM, a PTC controller, a PTC temperature sensor, and a PTC. The vehicle controller is respectively connected to the central control screen, the battery management system BMS, the HVCM, and the PTC controller; the PTC controller is respectively connected to the PTC temperature sensor and the PTC; the HVCM is connected to the BMS; the central control screen panel is equipped with a panel temperature gear knob, a panel air volume gear knob, a defrost and defogging button, and a PTC switch, and their respective status signals are collected by the central control screen and sent to the vehicle controller; the BMS is used to monitor the battery The HVCM is used to monitor the vehicle's high-voltage status and send a battery heating request signal to the vehicle controller; the HVCM is used to monitor the vehicle's high-voltage status and feed back a battery charging status signal to the vehicle controller; the PTC temperature sensor is used to collect the PTC water outlet temperature and send it to the vehicle controller through the PTC controller; the vehicle controller is used to process the received signal and output a PTC control signal to the PTC controller to control the output power of the PTC; the PTC controller is also used to monitor the actual output power of the PTC, diagnose the PTC and obtain the fault level, and feed back the monitoring and diagnosis results to the vehicle controller; the method includes the following steps: Step S1: The vehicle controller collects signals from system components during operation, including PTC switch signals, panel temperature knob position signals, air volume knob signals, defrost and defogger button signals, PTC temperature sensor signals, battery status, vehicle high voltage status, battery heating request signals from the BMS, battery charging status signals from the HVCM, actual PTC output power, and PTC fault levels. Step S2: The vehicle controller processes the collected signal and outputs a PTC control signal to the PTC controller to control the output power of the PTC. The vehicle controller processes the received signal and determines whether to issue a PTC enable request. The PTC enable request is triggered only when the following conditions are met: (1) The power-on mode is in a non-OFF state, and the main positive and negative relays are closed; or in the battery charging state, the high-voltage control module feedback battery pack charging state is: charging and heating state, or pure heating state; (2) The PTC heater failure level does not exceed the preset level; (3) The communication between the vehicle controller and the PTC controller is normal; (4) The panel temperature knob is within the preset range and the panel air volume knob is activated; (5) The PTC switch is in the on state; or the BMS issues a battery heating request in non-slow charging mode; or the BMS issues a battery heating request in slow charging mode and the charging status is not in the initialization or pending state; (6) No PTC fault signal is received; After the PTC is enabled, the vehicle controller processes the received signal, including calculating the bus output PTC power P of the vehicle controller. 总线 ,in: (1) When the vehicle is not charging, P Req =P 面板 +P BMS ; P 总线 =Min(P BMSLimit ,P Req ) Among them, P Req Indicates the panel PTC request power P of the central control screen 面板 and BMS battery pack heating PTC request power P BMS The sum of P BMSLimit Indicates the maximum available power allocated to the PTC by the battery pack; (2) When the vehicle is in charging state and the main positive and negative relays are closed, P 总线 =Min{(P HVCM +P BMSLimit ),P Req }; When the vehicle is in charging state and the main positive relay is disconnected, P 总线 =Min(P HVCM ,P Req ); Among them, P HVCM Indicates the PTC power requested by the high voltage control module that the vehicle controller is allowed to request.

2. The control method of a PTC control system for a new energy vehicle according to claim 1, characterized in that: After receiving the PTC control signal from the vehicle controller, the PTC controller drives the working power of the PTC to increase or decrease at a rate of 2 kW / s. When there is no PTC enable request, the PTC power working is immediately reset to 0.

3. The control method of a PTC control system for a new energy vehicle according to claim 1, characterized in that: For the P Req , when only the central control screen panel PTC heating request, obviously there is P Req =P 面板 ; When there is only a BMS battery pack heating request, there is obviously P Req =P BMS ,in: If the vehicle is in the Ready state, that is, ready to drive, then P BMS = 0; If the main positive and negative relays are closed after the charging gun is inserted but the BMS does not allow charging, then P BMS = 3KW; If the main positive and negative relays are closed after the charging gun is inserted and the BMS allows charging, the P value is obtained by looking up the table based on the difference between the target heating temperature of the battery pack and the water inlet temperature of the battery pack. BMS .

4. The control method of a PTC control system for a new energy vehicle according to claim 1 or 3, characterized in that: For the P Req , only the P Req When the power is greater than the preset threshold, the P Req Otherwise, let the output P Req =0.

5. The control method of a PTC control system for a new energy vehicle according to claim 1 or 3, characterized in that: After the PTC is enabled, the vehicle controller processes the received signal, including requesting the PTC power P of the central control screen. 面板 Restrictions are imposed, including: Limitation 1: When the defogger / defrost button is not detected and there is no battery heating request, the panel PTC of the central control screen requests power P 面板 Restrictions are made, namely: If T OutTemp ≥55℃, then P Max =1.5KW; If T OutTemp ≤45℃, then P Max =8.5KW; If 45℃<T OutTemp <55℃, then according to T OutTemp Lookup table for P 面板 impose restrictions; Among them, T OutTemp Indicates the PTC outlet temperature; P Max Indicates the maximum requested power allowed for the panel PTC; Limitation 2: According to the panel temperature knob gear and air volume knob gear lookup table, P 面板 impose restrictions; The final output of the central control screen panel PTC request power P 面板 , take the restrictions 1 and 2 under P 面板 The minimum value of .

6. The control method of a PTC control system for a new energy vehicle according to claim 1, characterized in that: After the PTC enable is triggered, the vehicle controller processes the received signal including PTC fault judgment, where: When the vehicle is not charging and not in high voltage state, no PTC fault is detected. In addition: (1) When the actual output power of PTC is equal to the bus output PTC power P 总线 When the error exceeds the preset error threshold, the PTC enable signal is turned off with a delay, and the PTC fault is determined and recorded; (2) After the PTC enable is triggered, if it is detected that the PTC does not start working within the preset time, it is judged as a PTC enable failure and recorded.

7. The control method of a PTC control system for a new energy vehicle according to claim 6, characterized in that: Once a PTC fault occurs, the vehicle will keep the fault record in the corresponding working cycle and will not be automatically cleared until the fault is repaired and reset manually.

Images