Control method for electric heater of new energy extended-range hybrid electric vehicle

Abstract

The invention belongs to the technical field of heat management of new energy hybrid vehicles, particularly relates to a control method for an electric heater of a new energy extended-range hybrid vehicle, and provides the following scheme for solving the problems that the SOC of a power battery is rapid and oil consumption is increased due to the existing heat management technology of the new energy hybrid vehicle. Comprising double heating loops and a control system, the double heating loops comprise an engine coolant heating loop and an electric PTC heating loop, and the control system comprises a vehicle control unit (VCU), an engine control unit (ECU) and an all-in-one controller. The use comfort of the vehicle is improved, heating mode switching is smooth, noise generated by frequent starting and stopping of an engine is avoided, meanwhile, the temperature of a cab can be rapidly increased through the mixed heating mode, and the heating response speed in the low-temperature environment is increased by 25% or above.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology for new energy hybrid vehicles, and in particular to a control method for electric heating in a new energy range-extended hybrid vehicle. Background Technology

[0002] Range-extended hybrid electric vehicles combine the low energy consumption advantages of pure electric vehicles with the range stability of traditional fuel vehicles. They are increasingly widely used in the commercial vehicle sector. In low-temperature environments during winter, the need for heating in the cab is urgent. The existing heating methods of range-extended hybrid vehicles mainly rely on electric PTC heater systems for overall vehicle heating management.

[0003] For example, Chinese patent application CN118003830A discloses a thermal management control method, device, thermal management system, and vehicle for a hybrid vehicle, designing a vehicle thermal management technology field. The thermal management control method for the hybrid vehicle includes: determining a thermal management mode based on whether a cockpit heating command is received and the cell temperature of the hybrid vehicle's battery; when the thermal management mode is a battery heating mode, controlling a first heating pipeline and a second heating pipeline to heat the hybrid vehicle's battery, wherein the first heating pipeline houses the battery and is connected in parallel with the second heating pipeline via a heat exchange device, and the second heating pipeline houses an engine and an electric heater connected in series. Existing thermal management technologies for hybrid new energy vehicles have the following problems: the charging and discharging efficiency of the power battery decreases in low-temperature environments, and the electric PTC heater consumes a lot of electricity for heating, which can cause the power battery's SOC to drop rapidly to the engine's critical starting point, leading to frequent engine starts. This increases fuel consumption and shortens the pure electric driving range. Existing technologies are not easy to solve these problems. Therefore, there is an urgent need for a control method for the electric heater in new energy range-extended hybrid vehicles to solve the above problems. Summary of the Invention

[0004] Based on the technical problem that current thermal management technology for new energy hybrid vehicles leads to rapid state of charge (SOC) of the power battery and increased fuel consumption, this invention proposes a control method for the electric heater in a new energy range-extended hybrid vehicle.

[0005] The present invention proposes a control method for electric heating in a new energy range-extended hybrid vehicle, including a range-extended hybrid vehicle comprising dual heating circuits and a control system; Dual heating circuits: including an engine coolant heating circuit and an electric PTC heating circuit; Control system: including vehicle control unit (VCU), engine control unit (ECU), and multi-function controller; The specific steps for controlling the electric heater in a new energy range-extended hybrid vehicle are as follows: S1: The vehicle controller (VCU) collects vehicle operating parameters via the CAN bus. These operating parameters include engine start status, coolant temperature information, power battery SOC value, and cab set temperature. S2: Determine the heating mode based on the obtained operating parameters. The heating mode includes a separate heating mode for the electric PTC heating circuit, a separate heating mode for the engine coolant heating circuit, and a mixed heating circuit heating mode. S3: The vehicle control unit (VCU) sends a mode switching command to the all-in-one controller to achieve automatic switching of heating modes.

[0006] Preferably, the engine controller (ECU) is used to collect coolant temperature information and operating parameters, and to feed back the collected coolant temperature information and operating parameters to the vehicle controller (VCU).

[0007] Preferably, the electric PTC heating circuit includes an electric PTC heater and a matching control module.

[0008] Preferably, the engine coolant heating circuit includes a circulation pipeline for engine coolant, a heat exchanger, and a circulation pump for circulating coolant.

[0009] Preferably, the control logic for the heating mode is as follows: When the engine is not started, or when the engine is started but the coolant temperature is lower than the first preset threshold T1, the electric PTC heating circuit is activated for separate heating. When the engine is started and the coolant temperature is higher than the second preset threshold T2, the engine coolant heating circuit separate heating mode is activated, and the electric PTC heating circuit is turned off. When the engine is started and the coolant temperature is between the first preset threshold T1 and the second preset threshold T2, the hybrid heating mode is activated, and the electric PTC heating circuit and the engine coolant heating circuit work together.

[0010] Preferably, the first preset threshold T1 is in the range of 40℃-55℃, the second preset threshold T2 is in the range of 60℃-75℃, and T2 is greater than T1.

[0011] Preferably, in the hybrid heating mode, the vehicle control unit (VCU) dynamically adjusts the power output of the electric PTC heater based on the difference between the set temperature and the actual temperature in the cab. The greater the difference between the set temperature and the actual temperature in the cab, the higher the power of the electric PTC heater; the smaller the difference between the set temperature and the actual temperature in the cab, the lower the power of the electric PTC heater.

[0012] Preferably, it also includes power battery SOC protection logic, which protects the power battery when its SOC value is lower than a preset protection threshold S: When the engine is running, the engine coolant heating circuit is in heating mode. When the engine is not running, the engine start procedure is triggered. Once the coolant temperature reaches the set value, the engine stops and the residual heat from the engine coolant heating circuit is used for heating.

[0013] Preferably, the preset protection threshold S is in the range of 20%-30%.

[0014] The beneficial effects of this invention are as follows: 1. The control method of the electric heater in this new energy range-extended hybrid vehicle improves the comfort of vehicle use, the switching of heating modes is smooth, and the noise caused by frequent engine start-stop is avoided. At the same time, the hybrid heating mode can quickly increase the temperature in the cab, and the heating response speed is increased by more than 25% in low temperature environments.

[0015] 2. The control method of the electric heater in this new energy range-extended hybrid vehicle makes energy utilization more efficient, recovers the waste heat of the engine to replace the electric PTC heating, reduces the power consumption by 30%-50%, reduces the frequency of engine starts, increases the pure electric range by 15%-20%, reduces fuel consumption by 8%-12%, reduces the working time of the electric PTC heater by 40%-60%, and extends the service life of its controller by 1.5-2 times. 3. The control method for the electric heater of this new energy range-extended hybrid vehicle has strong adaptability, supports dynamic threshold adjustment and demand intensity adaptation, can meet the usage needs of different regions and different ambient temperatures, and is fully compatible with multiple platforms such as HV5, HV3, HV9, HV3E and DR12H-002 model. 4. The control method for the electric heater in this new energy range-extended hybrid vehicle can effectively ensure safety by adding a power battery SOC protection logic mechanism to avoid battery damage caused by over-discharge and improve vehicle operation safety. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the control principle of a control method for an electric heater in a new energy range-extended hybrid vehicle proposed in this invention. Detailed Implementation

[0017] Example 1: To improve driver comfort when using a new energy range-extended hybrid vehicle, refer to... Figure 1 A control method for electric heating in a new energy range-extended hybrid vehicle, the range-extended hybrid vehicle including dual heating circuits and a control system; Dual heating circuits: including an engine coolant heating circuit and an electric PTC heating circuit; Control system: including vehicle control unit (VCU), engine control unit (ECU), and multi-function controller.

[0018] Furthermore, the engine controller (ECU) is used to collect coolant temperature information and operating parameters. The ECU also collects and transmits core engine data, including real-time engine operating parameters, the core of which is engine coolant temperature information. The coolant temperature is acquired through a set coolant temperature sensor, and the engine start / stop status, real-time engine speed, and other basic operating data are collected simultaneously.

[0019] During data transmission, the vehicle controller (VCU), engine controller (ECU), and multi-function controller are connected via a CAN bus. The engine controller (ECU) sends the collected coolant temperature information, engine status, and other data to the vehicle controller (VCU) in real time via the CAN bus, providing data support for the VCU to determine the heating mode.

[0020] The three-in-one controller communicates with the vehicle control unit (VCU) via a CAN bus. It receives heating mode logic commands from the VCU, such as when the power battery SOC is too low, the VCU triggers an engine start program command, and the engine control unit (ECU) executes the start to ensure stable engine operation and provide residual heat.

[0021] Furthermore, the electric PTC heating circuit includes an electric PTC heater and a matching control module, with the electric PTC heater being the core component, enabling rapid heating to quickly heat the cab of the range-extended hybrid vehicle in winter. Its specific functions include: Rapid heating: When the engine is not running or the water temperature is not up to standard while the engine is running, the electric PTC heater directly converts electrical energy into heat energy to quickly increase the temperature of the circulating medium. This solves the problem of slow heating in low-temperature environments and ensures that the cab reaches the set temperature within 10-15 minutes.

[0022] Synergistic heating: In the hybrid heating mode, the coolant temperature is between T1 and T2. The heating power is dynamically adjusted according to the temperature difference in the cab. It works in conjunction with the waste heat from the engine to maintain a stable temperature and avoid the phenomenon of alternating hot and cold air coming out of the air outlet.

[0023] Low temperature protection: In extreme low temperature environments, when the ambient temperature is below -30℃, or when the power battery SOC has not reached the protection threshold, the electric PTC heater assists in heating in low power mode, taking into account both heating needs and energy saving, and avoiding excessive discharge of the power battery leading to an excessively low power battery SOC.

[0024] Safe heating: The electric PTC heater relies on the inherent characteristics of the PTC core. After the temperature reaches the Curie temperature point, the electric PTC heater heats up stably, preventing the rapid increase of resistance and overheating. At the same time, through linkage with the control module, it achieves dual protection against dry burning and overheating.

[0025] The control module for the PTC heater is the core of command execution and safety monitoring for the electric PTC heater. It is linked with the vehicle control unit (VCU) and the multi-function controller via the CAN bus. Its specific functions include: Used for command reception and execution: Receives start / stop and power adjustment commands issued by the vehicle controller (VCU), and realizes stepless adjustment of heater power through PWM technology. In order to respond to different heating demand intensities, its adjustment accuracy is controlled within the range of 10W.

[0026] Status monitoring and feedback: Real-time acquisition of operating current, voltage, temperature and circulating medium temperature data of PTC heater, and synchronous feedback to VCU via CAN bus, providing data support for heating mode switching.

[0027] Multiple safety protections: To avoid damage to PTC heater components and vehicle safety risks, the control module integrates overcurrent, overvoltage, undervoltage, short circuit, open circuit, over-temperature, and dry-burn protection logic. When an abnormality is triggered, the control module immediately cuts off the power supply to the PTC heater and sends an alarm signal to the vehicle controller (VCU).

[0028] Soft start control: In order to protect the vehicle's high-voltage power supply system and ensure the stability of the vehicle's electrical system, the control module adopts soft start technology, and the inrush current during startup does not exceed 10% of the rated current.

[0029] Furthermore, the engine coolant heating circuit includes engine coolant circulation pipes, a heat exchanger, and a circulation pump for circulating coolant. The engine coolant circulation pipes use EPDM rubber hoses, which can be used normally at temperatures ranging from -40℃ to 120℃. The EPDM rubber hoses are connected to the engine block water outlet, extend along the engine block water outlet, and are connected to the heat exchanger for conduction. After passing through the heat exchanger, the coolant flows back to the engine water pump inlet, forming a closed-loop circulation channel. The pipe diameter is designed to be φ25mm according to the vehicle's thermal management requirements, ensuring that the coolant flow resistance is ≤0.03MPa and guaranteeing heat transfer efficiency.

[0030] The heat exchanger adopts a plate-fin structure with a core material of 304 stainless steel and a heat exchange area of ​​≥0.8㎡. One side of the heat exchanger is connected to the engine coolant circulation loop, and the other side is connected in series with the cab heating air duct. The heat exchanger transfers the engine waste heat in the coolant to the cab airflow through air-liquid heat exchange.

[0031] The circulating pump is a 12V DC brushless water pump with a rated flow rate ≥15L / min and a rated head ≥3m. The speed is adjusted according to the instructions issued by the vehicle controller (VCU) to dynamically match the coolant circulation flow rate. To ensure the heating requirements of the vehicle and reduce pump energy consumption, the circulating pump can be infinitely speed-regulated. The heat exchanger is equipped with a temperature sensor installed on the coolant outlet side to collect the coolant temperature after heat exchange in real time and feed it back to the vehicle controller (VCU). The heat exchanger is also equipped with a flow sensor installed at the outlet of the circulating pump to monitor the flow status of the circulating pipeline. When the flow rate is lower than 5L / min, the vehicle controller (VCU) is triggered to alarm and reduce the heat exchange power to prevent the heat exchanger from burning out. The entire circuit achieves efficient recovery of engine waste heat and stable heating output through the coordinated work of the above components.

[0032] The control logic for the electric heater control method in new energy range-extended hybrid vehicles is as follows: Setting parameters: Set the first preset threshold T1=45℃, the second preset threshold T2=65℃, and the power battery SOC preset protection threshold S=25%; Trigger command: After the driver turns on the cab heater, the vehicle control unit (VCU) receives the heating demand signal and simultaneously collects parameters such as engine status, coolant temperature, power battery SOC value, and actual cab temperature via the CAN bus. Heating mode determination and execution: If the engine is not running and the power battery SOC is ≥25%, the vehicle will run in pure electric mode: the vehicle controller (VCU) will send a command to the multi-function controller to turn on the electric PTC heating circuit, and the electric PTC heater will work at its rated power to quickly increase the temperature of the cab. If the engine is not running, but the SOC of the power battery is less than 25%: the vehicle controller (VCU) sends a command to trigger the engine to start, and the engine controller (ECU) controls the engine to start. At this time, the electric PTC heater provides low-power auxiliary heating. When the water temperature rises to the T1 threshold of 45°C, the power of the electric PTC heater is gradually reduced. When the water temperature reaches the T2 threshold of 65°C, the electric PTC heater is turned off, and the engine waste heat is used for separate heating. If the engine is already running, the new energy range-extended hybrid vehicle will operate in range-extending mode: when the water temperature is <45℃, the electric PTC heater and the engine waste heat circuit work together to heat the vehicle, which is a hybrid heating mode; when the water temperature is 45℃-65℃, the power of the electric PTC heater gradually decreases from high power operation to stop as the water temperature rises; when the water temperature is ≥65℃, heating is only provided through the engine waste heat circuit.

[0033] When using it: The specific steps for controlling the electric heater in a new energy range-extended hybrid vehicle are as follows: S1: The vehicle controller (VCU) collects vehicle operating parameters via the CAN bus. These operating parameters include engine start status, coolant temperature information, power battery SOC value, and cab set temperature. S2: Determine the heating mode based on the obtained operating parameters. The heating mode includes a separate heating mode for the electric PTC heating circuit, a separate heating mode for the engine coolant heating circuit, and a mixed heating circuit heating mode. S3: The vehicle control unit (VCU) sends a mode switching command to the all-in-one controller to achieve automatic switching of heating modes.

[0034] Example 2: To address the issue of dynamically adjusting the threshold to adapt to different ambient temperatures and improve driving comfort, refer to... Figure 1 Based on Example 1, an ambient temperature sensor was added.

[0035] The control logic for the electric heater control method in new energy range-extended hybrid vehicles is as follows: The ambient temperature sensor is used to detect the external ambient temperature of the vehicle. The ambient ambient temperature is marked as T. 环 The vehicle control unit (VCU) dynamically adjusts the T1 and T2 thresholds based on the ambient temperature to adapt to different low-temperature scenarios. Ambient temperature T 环 ≥-10℃: T1=50℃, T2=70℃; Ambient temperature -20℃ < T 环 <-10℃: T1=45℃, T2=65℃; Ambient temperature T 环 ≤-20℃: T1=40℃, T2=60℃ Low temperature environment: at T 环 At ≤-20℃, the engine temperature rises slowly after starting. By automatically lowering T1 to 40℃ and controlling the control logic, the hybrid heating mode can be activated in advance to avoid the cab temperature rising too slowly. Mild low temperature environment: in T 环 At temperatures ≥-10℃, the T1 and T2 thresholds are automatically increased to reduce the usage time of the electric PTC heater and further reduce energy consumption.

[0036] If the ambient temperature is -25℃, the engine will enter the mixed heating mode when the coolant temperature rises to 40℃ after starting the engine. The electric PTC heater will assist in the mixed heating mode with a power of 3kW. After the coolant temperature rises to 60℃, the electric PTC heater will be turned off, and the engine will switch to the heating mode of using the engine's waste heat and turning off the electric PTC heater. If the ambient temperature is -5℃, the engine will enter the mixed heating mode when the coolant temperature rises to 50℃ after starting the engine. When the coolant temperature reaches 70℃, the engine will switch to the heating mode of using the engine's waste heat and turning off the electric PTC heater.

[0037] Example 3: To address the primary need for heating and ensure the vehicle interior temperature quickly reaches the set temperature, refer to... Figure 1 A heating demand intensity determination module has been added to the vehicle control unit (VCU) to determine the difference Δ between the set temperature and the actual temperature in the cab. T , where Δ T =Vehicle interior set temperature - Actual vehicle interior temperature, used to dynamically adjust the power of the electric PTC heater and the speed of the engine coolant circuit circulation pump.

[0038] The control logic for the electric heater control method in new energy range-extended hybrid vehicles is as follows: Strong demand setting Δ T ≥8℃: The electric PTC heater operates at its rated power, which is 5kW, and the circulating pump in the engine coolant circuit operates at high speed. The medium demand setting is 4℃≤Δ T <8℃: The power of the electric PTC heater is reduced to 3kW, and the circulating pump in the engine coolant circuit operates at medium speed; Weak demand setting Δ T <4℃: The power of the electric PTC heater is reduced to 1kW, and the circulation pump of the engine coolant circuit operates at low speed.

[0039] In the hybrid heating mode, the vehicle control unit (VCU) calculates Δ in real time. T According to Δ T Dynamically adjust output parameters as needed: Initial heating stage Δ T When the temperature is ≥8℃, the electric PTC heater operates at its rated power, and the circulating pump in the engine coolant circuit operates at high speed to quickly raise the temperature inside the vehicle. When Δ T When the temperature drops to the 4℃-8℃ range, the power of the electric PTC heater gradually decreases, and the circulation pump of the engine coolant circuit is adjusted to medium speed to maintain the rate of temperature rise inside the vehicle. When Δ T At temperatures below 4℃, the electric PTC heater operates at low power for heat preservation, and the circulating pump in the engine coolant circuit operates at low speed for energy saving. Once the water temperature reaches T2, the electric PTC heater is turned off, and the engine coolant circuit circulation pump operates according to Δ... T Adjust the engine speed to maintain a continuous and stable temperature inside the vehicle.

[0040] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A control method for the electric heater in a new energy range-extended hybrid vehicle, characterized in that, Range-extended hybrid vehicles include dual heating circuits and a control system; Dual heating circuits: including an engine coolant heating circuit and an electric PTC heating circuit; Control system: including vehicle control unit (VCU), engine control unit (ECU), and multi-function controller; The specific steps for controlling the electric heater in a new energy range-extended hybrid vehicle are as follows: S1: The vehicle controller (VCU) collects vehicle operating parameters via the CAN bus. These operating parameters include engine start status, coolant temperature information, power battery SOC value, and cab set temperature. S2: Determine the heating mode based on the obtained operating parameters. The heating mode includes a separate heating mode for the electric PTC heating circuit, a separate heating mode for the engine coolant heating circuit, and a mixed heating circuit heating mode. S3: The vehicle control unit (VCU) sends a mode switching command to the all-in-one controller to achieve automatic switching of heating modes.

2. The control method for electric heating in a new energy range-extended hybrid vehicle according to claim 1, characterized in that, The engine controller (ECU) is used to collect coolant temperature information and operating parameters, and then feeds the collected coolant temperature information and operating parameters back to the vehicle controller (VCU).

3. The control method for electric heating in a new energy range-extended hybrid vehicle according to claim 1, characterized in that, The electric PTC heating circuit includes an electric PTC heater and a matching control module.

4. The control method for the electric heater of a new energy range-extended hybrid vehicle according to claim 3, characterized in that, The engine coolant heating circuit includes engine coolant circulation pipes, a heat exchanger, and a circulation pump for circulating the coolant.

5. The control method for electric heating in a new energy range-extended hybrid vehicle according to claim 1, characterized in that, The control logic for the heating mode is as follows: When the engine is not started, or when the engine is started but the coolant temperature is lower than the first preset threshold T1, the electric PTC heating circuit is activated for separate heating. When the engine is started and the coolant temperature is higher than the second preset threshold T2, the engine coolant heating circuit separate heating mode is activated, and the electric PTC heating circuit is turned off. When the engine is started and the coolant temperature is between the first preset threshold T1 and the second preset threshold T2, the hybrid heating mode is activated, and the electric PTC heating circuit and the engine coolant heating circuit work together.

6. The control method for the electric heater of a new energy range-extended hybrid vehicle according to claim 5, characterized in that, The first preset threshold T1 has a value range of 40℃-55℃, and the second preset threshold T2 has a value range of 60℃-75℃, with T2 being greater than T1.

7. The control method for electric heating in a new energy range-extended hybrid vehicle according to claim 6, characterized in that, In the hybrid heating mode, the vehicle control unit (VCU) dynamically adjusts the power output of the electric PTC heater based on the difference between the set temperature and the actual temperature in the cab. The greater the difference between the set temperature and the actual temperature in the cab, the higher the power of the electric PTC heater; the smaller the difference between the set temperature and the actual temperature in the cab, the lower the power of the electric PTC heater.

8. The control method for electric heating in a new energy range-extended hybrid vehicle according to claim 1, characterized in that, It also includes power battery SOC protection logic, which prevents the power battery from falling below a preset protection threshold S: When the engine is running, the engine coolant heating circuit is in heating mode. When the engine is not running, the engine start procedure is triggered. Once the coolant temperature reaches the set value, the engine stops and the residual heat from the engine coolant heating circuit is used for heating.

9. The control method for the electric heater of a new energy range-extended hybrid vehicle according to claim 8, characterized in that, The preset protection threshold S ranges from 20% to 30%.

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