A power battery pack test system and thermal management energy consumption test method

Abstract

The present invention relates to a power battery pack test system and a thermal management energy consumption test method, including an environmental simulation system, the environmental simulation system including a high and low temperature environment simulation test box, a battery pack bracket, a fan and a windproof mechanism, a battery pack bracket and a fan are arranged in the high and low temperature environment simulation test box, a power battery pack is arranged on the battery pack bracket, and a windproof mechanism is arranged on the power battery pack; a control acquisition system includes a controller, a relay and a host computer; the control acquisition system is provided with a CAN bus and a power harness, and the control acquisition system is respectively connected to the power battery pack, the air conditioning system, and the battery charging and discharging system through the CAN bus and the power harness; the battery charging and discharging system is connected to the host computer through the CAN bus, and the control acquisition system and the fan are connected through the CAN bus. The present invention realizes that the energy conversion process of the entire system is consistent with the actual vehicle state, and calculates energy consumption data according to intervals, thereby improving the accuracy of detection data.

Description

Technical Field

[0001] The present invention relates to the technical field of power battery testing, and in particular to a power battery pack testing system and a thermal management energy consumption testing method. Background Art

[0002] With the rapid development of the new energy vehicle market, power batteries, as the core components that provide power for electric vehicles, have always been one of the most concerned issues for users in terms of performance and safety. Since the battery pack is sensitive to temperature during operation, whether it is overheated or overcooled, the battery performance will be significantly reduced, and even safety risks such as thermal runaway may occur. Therefore, power battery thermal management technology plays an extremely important role in ensuring the performance and safety of power batteries. The thermal management technology of power batteries is a technology that solves the problem of poor battery working conditions when the temperature is too high or too low through reasonable design based on the influence of temperature on battery performance, combined with the electrochemical characteristics and heat generation mechanism of the battery, thereby improving the overall performance of the battery.

[0003] The functions of thermal management system are mainly divided into two aspects: cooling and heating. At present, most power battery packs use liquid heating or cooling to heat or cool the battery. Liquid cooling plates are designed and installed at the bottom and around the battery. There are sealed pipes inside the liquid cooling plates. The temperature of the coolant is adjusted under the action of the refrigeration unit or PTC. Then it can circulate in the pipes driven by the water pump to cool or heat the battery.

[0004] The electric energy consumed by the battery thermal management system of electric vehicles during normal driving comes from the power battery. The consumption of this part of the electric energy will reduce the remaining power of the power battery pack, which will lead to a reduction in the driving range of the electric vehicle. If this part of the power is not consumed, the temperature of the battery pack will be at a high or low level, which will also cause the battery pack to not release the power, let alone a good driving range. Therefore, based on the contradiction between the thermal management energy consumption and the battery pack temperature, an optimal balance must be found when designing the battery pack thermal management strategy to achieve the maximum discharge capacity of the power battery with the least thermal management energy consumption.

[0005] At present, when the industry tests the performance of power battery packs, it generally adds an additional liquid cooling unit to adjust the battery pack temperature. Since this part of the thermal management energy consumption does not come from the power battery pack to be tested, and the influence of the battery's own heat generation during discharge is ignored, the final test results will deviate greatly from the actual usage scenario. In addition, due to the deviation of the data, the thermal management strategy designed based on this data will also have a certain degree of deviation, making it impossible to maximize the performance of the power battery pack, thereby affecting the vehicle's range. Summary of the invention

[0006] In order to solve the problems that the test results of existing test equipment deviate greatly from the actual usage scenarios and the detection data are inaccurate, the present invention proposes a power battery pack test system and a power battery pack thermal management energy consumption test method. The power battery pack test system is constructed to make the energy conversion process of the entire system consistent with the actual vehicle state. The energy consumption data is calculated by interval through the thermal management energy consumption test method, so as to provide data support for the design and optimization of the thermal management strategy of the power battery pack.

[0007] In order to achieve the above-mentioned purpose, the present invention provides a power battery pack test system in a first aspect, including an environmental simulation system, an air conditioning system, a control and acquisition system, a battery charging and discharging system and a tested object, wherein the tested object includes a power battery pack, and the environmental simulation system includes a high and low temperature environment simulation test box, a battery pack bracket, a fan and a windproof mechanism, wherein a battery pack bracket and a fan are arranged in the high and low temperature environment simulation test box, a power battery pack is arranged on the battery pack bracket, and a windproof mechanism is arranged on the power battery pack;

[0008] The air conditioning system includes a cooling and heating unit, a water pump, a flow sensor and a temperature sensor, and the control and acquisition system includes a controller, a relay and a host computer;

[0009] The control acquisition system is provided with a CAN bus and a power harness, and the control acquisition system is connected to the power battery pack, the air conditioning system, and the battery charging and discharging system through the CAN bus and the power harness respectively;

[0010] The control acquisition system and the fan are connected via a CAN bus;

[0011] The battery charging and discharging system is connected to the host computer through a CAN bus.

[0012] Furthermore, the battery pack bracket is a square bracket, the upper end surface of the battery pack bracket is hollow, the power battery pack is arranged on the upper end surface of the battery pack bracket, an insulating pad made of rubber material is arranged between the upper end surface of the battery pack bracket and the power battery pack, a windproof mechanism is arranged on the upper part of the power battery pack, the windproof mechanism is a square cover-like structure, the windproof mechanism is sleeved on the top and sides of the power battery pack, a filling layer made of thermal insulation material is arranged between the windproof mechanism and the power battery pack, and the filling layer is glued and fixed to the windproof mechanism.

[0013] The high and low temperature environment simulation test box is used to provide a simulated environment temperature to be tested, and the high and low temperature range can cover usage scenarios in all seasons.

[0014] The windproof mechanism is used to simulate the protection of the vehicle chassis to the top and surrounding areas of the battery pack.

[0015] The battery charging and discharging system is used to charge or discharge the power battery pack, and can simulate the feedback and consumption of power battery pack electric energy by a real vehicle under different working conditions;

[0016] Furthermore, a fan is arranged on one side of the battery pack bracket, and the fan is connected to an external power supply.

[0017] The fan is used to simulate the air disturbance that the power battery pack is subjected to when the vehicle is actually driving.

[0018] Furthermore, the coolant outlet and water return port of the air-conditioning system are both provided with pipes, and the other ends of the pipes are respectively connected to the water inlet and water outlet of the power battery pack.

[0019] The specifications, models and amounts of the cooling and heating units and the coolant filling are consistent with those of the actual vehicle, and the outer layer of the cooling and heating unit coolant tank and connecting pipes are equipped with a thermal insulation layer. The air conditioning system is used to heat or cool the coolant and circulate the coolant at the target temperature to the liquid cooling pipe of the power battery pack.

[0020] Furthermore, the controller is connected to the host computer via a CAN bus communication.

[0021] The control acquisition system is used to collect all relevant data in the power battery pack and send control instructions. Before the test, the thermal management strategy to be tested and the battery pack test conditions can be set through the host computer program, including charging and discharging parameters, heating or cooling temperature, liquid flow, start or stop conditions, wind speed, etc.

[0022] A power battery pack test system, including but not limited to applications in power battery pack low-temperature heating rate testing, power battery pack cooling rate testing, power battery pack comprehensive operating condition testing and power battery pack thermal management energy consumption testing.

[0023] A second aspect of the present invention provides a method for testing thermal management energy consumption of a power battery pack, comprising:

[0024] Step 1: Charge the power battery pack by controlling the battery charging and discharging system through the host computer until the SOC (State of Charge) is 100%;

[0025] Step 2: Adjust the temperature of the high and low temperature environment simulation test box to Tm (the ambient temperature value during the working condition), and let it stand until the temperature of the power battery pack is within Tm±1℃; (this step can be assisted by the air conditioning system to reduce the environmental adaptation time);

[0026] Step 3: Import the test conditions through the host computer, and input the critical temperature value, coolant target temperature value and flow value for starting and stopping the air conditioning system according to the thermal management strategy;

[0027] Step 4: Perform the test according to the test conditions. The controller frequently controls the relay to open and close so that the battery charging and discharging system, the cooling and heating unit, and the water pump respond to the output. The controller controls the fan speed in real time according to the vehicle speed to adjust the wind speed. The data collection cycle is 0.1s, and data is collected for the power battery pack, air conditioning system, battery charging and discharging system, and fan.

[0028] Step 5: If the collected temperatures of the power battery pack meet the critical temperature value for stopping the air conditioning system, the controller controls the cooling and heating unit to stop working immediately. When the collected temperatures of the power battery pack meet the critical temperature value for starting the air conditioning system, the controller controls the cooling and heating unit to restart again.

[0029] Step 6: After the test condition is completed, the number of cycles of the imported test condition can be set through the host computer;

[0030] Step 7: The host computer analyzes and calculates the effective data collected at each moment and outputs the corresponding thermal management energy consumption data.

[0031] Furthermore, the test conditions in step 3 include time, discharge current, feedback current and vehicle speed.

[0032] Furthermore, the test condition execution test in step 4 also includes:

[0033] The discharge current value of the charge and discharge system at each time point should be the difference between the discharge current value in the test condition and the working current value of the cooling and heating unit;

[0034] The charging current value of the charging and discharging system at each time point should be the sum of the feedback current value in the test condition and the working current value of the cooling and heating unit;

[0035] During the discharge process of the power battery pack, if the maximum allowable discharge current value of the power battery pack is less than the discharge current value in the test condition, the discharge is performed at the maximum allowable discharge current value of the power battery pack;

[0036] During the charging process of the power battery pack, if the maximum allowable feedback current value of the power battery pack is less than the feedback current value in the test condition, charging is performed with the maximum allowable feedback current value of the power battery pack.

[0037] Furthermore, the thermal management energy consumption data in step 7 is as shown in formulas (1) to (4):

[0038] P t =U t ×I t (1);

[0039] Among them, U t is the actual input voltage of the thermal management system at time t, I tis the actual working current, P t is the instantaneous power of the thermal management system at time t;

[0040] W t =U t ×I t ×0.1 (2);

[0041] Among them, W t is the energy consumed by the thermal management system at time t;

[0042] Assuming that the working time intervals of the thermal management system during the entire test process are t0-t1, t2-t3 and t4-t5 respectively, the total energy consumption of the thermal management system of the power battery pack (5) during the entire test process is shown in formula (3):

[0043]

[0044] Combined with the vehicle speed data, it is converted into the equivalent driving range in the time period t0-t5 through formula (4);

[0045]

[0046] The unit of v is km / h.

[0047] Through the above method, the energy consumption of power battery packs under different thermal management control strategies can be compared and studied, thus providing more accurate data support for the development and optimization of thermal management strategies for power battery packs. At the same time, the discharge power of the power battery pack during the test can also be obtained, which can be converted into equivalent driving range in combination with vehicle speed data.

[0048] Through the above technical solution, the beneficial effects of the present invention are:

[0049] 1. The present invention realizes that the energy conversion process of the system is consistent with the actual vehicle state. An environmental simulation system is set up to build the air-conditioning system, control and acquisition system, battery charging and discharging system and power battery pack together. The communication and thermal management energy consumption of the entire system are derived from the battery pack power. A windproof mechanism is designed to simulate the thermal insulation of the power battery pack by the chassis structure of the whole vehicle. The wind speed is changed by adjusting the fan speed to simulate the influence of the external air flow on the temperature of the bottom of the power battery pack during the driving process of the car. The fan uses an external power supply. The working state of the power battery pack in the actual use scenario of the whole vehicle is simulated to the greatest extent, so as to ensure that the test results are more accurate and reliable.

[0050] 2. A power battery pack thermal management energy consumption test method of the present invention collects and records the voltage, current, and power parameters of the thermal management system every 0.1s, and obtains the energy consumption data of the thermal management system in each working range after integral calculation and processing. The data has high accuracy, thereby providing data support for the design and optimization of the thermal management strategy of the power battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a structural principle diagram of a power battery pack test system of the present invention;

[0052] Figure 2 This is one of the structural schematic diagrams of a power battery pack test system of the present invention;

[0053] Figure 3 This is a second structural schematic diagram of a power battery pack test system of the present invention;

[0054] Figure 4 A schematic diagram of air disturbance in a power battery pack test system of the present invention;

[0055] Figure 5 This is a schematic diagram of the steps of a method for testing thermal management energy consumption of a power battery pack of the present invention.

[0056] Figure numbers: 1 is a high and low temperature environment simulation experiment box, 2 is a battery pack bracket, 3 is a fan, 4 is a windproof mechanism, 5 is a power battery pack, and 6 is an insulating pad. DETAILED DESCRIPTION

[0057] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

[0058] Example 1

[0059] like Figures 1 to 4 As shown, a power battery pack test system includes an environmental simulation system, an air conditioning system, a control and acquisition system, a battery charging and discharging system and a test object, wherein the test object includes a power battery pack 5, and the environmental simulation system includes a high and low temperature environment simulation test box 1, a battery pack bracket 2, a fan 3 and a windproof mechanism 4. The battery pack bracket 2 and the fan 3 are arranged in the high and low temperature environment simulation test box 1, the power battery pack 5 is arranged on the battery pack bracket 2, and the windproof mechanism 4 is arranged on the power battery pack 5;

[0060] The air conditioning system includes a cooling and heating unit, a water pump, a flow sensor and a temperature sensor, and the control and acquisition system includes a controller, a relay and a host computer;

[0061] The control acquisition system is provided with a CAN bus and a power harness, and the control acquisition system is respectively connected with the power battery pack 5, the air conditioning system, and the battery charging and discharging system through the CAN bus and the power harness;

[0062] The control acquisition system and the fan 3 are connected via a CAN bus;

[0063] The battery charging and discharging system is connected to the host computer through a CAN bus.

[0064] The battery pack bracket 2 is a square bracket, the upper end surface of the battery pack bracket 2 is hollowed out, a power battery pack 5 is arranged on the upper end surface of the battery pack bracket 2, an insulating pad 6 made of rubber material is arranged between the upper end surface of the battery pack bracket 2 and the power battery pack 5, a windproof mechanism 4 is arranged on the upper part of the power battery pack 5, the windproof mechanism 4 is a square cover-like structure, the windproof mechanism 4 is sleeved on the top and side of the power battery pack 5, a filling layer made of thermal insulation material is arranged between the windproof mechanism 4 and the power battery pack 5, and the filling layer is glued and fixed to the windproof mechanism 4.

[0065] A fan 3 is provided on one side of the battery pack support 2, and the fan 3 is connected to an external power supply. The fan speed can be automatically adjusted or manually adjusted according to the upper computer test working condition.

[0066] The coolant water outlet and water return port of the air conditioning system are both provided with pipes, and the other ends of the pipes are respectively connected to the water inlet and water outlet of the power battery pack 5.

[0067] The controller is connected to the host computer via a CAN bus communication.

[0068] A power battery pack test system, including but not limited to applications in a power battery pack 5 low temperature heating rate test, a power battery pack 5 cooling rate test, a power battery pack 5 comprehensive operating condition test, and a power battery pack 5 thermal management energy consumption test.

[0069] Example 2

[0070] like Figure 5 As shown, based on a power battery pack test system, in this embodiment, a power battery pack thermal management energy consumption test method includes:

[0071] Step 1: The upper computer controls the battery charging and discharging system to charge the power battery pack 5 until the SOC reaches 100%;

[0072] Step 2: Adjust the temperature of the high and low temperature environment simulation test box to Tm, and let it stand until the temperature of the power battery pack is within Tm±1℃;

[0073] Step 3: Import the test conditions through the host computer, and input the critical temperature value, coolant target temperature value and flow value for starting and stopping the air conditioning system according to the thermal management strategy;

[0074] Step 4: Perform the test according to the test conditions. The controller frequently controls the relay to open and close so that the battery charging and discharging system, the cooling and heating unit, and the water pump respond to the output. The controller controls the speed of the fan 3 in real time according to the vehicle speed to adjust the wind speed. The data collection cycle is 0.1s to collect data from the power battery pack 5, the air conditioning system, the battery charging and discharging system, and the fan 3.

[0075] Step 5: If the collected temperatures of the power battery pack 5 meet the critical temperature value for stopping the air conditioning system, the controller controls the cooling and heating unit to stop working immediately. When the collected temperatures of the power battery pack 5 meet the critical temperature value for starting the air conditioning system, the controller controls the cooling and heating unit to restart again.

[0076] Step 6: After the test condition is completed, the number of cycles of the imported test condition can be set through the host computer;

[0077] Step 7: The host computer analyzes and calculates the effective data collected at each moment and outputs the corresponding thermal management energy consumption data.

[0078] The test conditions described in step 3 include time, discharge current, feedback current, vehicle speed, heating or cooling temperature, liquid flow, start or stop conditions and wind speed.

[0079] The test condition execution test described in step 4 also includes:

[0080] The discharge current value of the charge and discharge system at each time point should be the difference between the discharge current value in the test condition and the working current value of the cooling and heating unit;

[0081] The charging current value of the charging and discharging system at each time point should be the sum of the feedback current value in the test condition and the working current value of the cooling and heating unit;

[0082] During the discharge process of the power battery pack 5, if the maximum allowable discharge current value of the power battery pack 5 is less than the discharge current value in the test condition, the discharge is performed at the maximum allowable discharge current value of the power battery pack 5;

[0083] During the charging process of the power battery pack 5 , if the maximum allowable feedback current value of the power battery pack 5 is less than the feedback current value in the test condition, charging is performed with the maximum allowable feedback current value of the power battery pack 5 .

[0084] The thermal management energy consumption data in step 7 is shown in formulas (1) to (4):

[0085] P t =U t ×I t (1);

[0086] Among them, U t is the actual input voltage of the thermal management system at time t, It is the actual working current, P t is the instantaneous power of the thermal management system at time t;

[0087] Q t =U t ×I t ×0.1 (2);

[0088] Among them, W t is the energy consumed by the thermal management system at time t;

[0089] Assuming that the working time intervals of the thermal management system during the entire test process are t0-t1, t2-t3 and t4-t5 respectively, the total energy consumption of the thermal management system of the power battery pack (5) during the entire test process is shown in formula (3):

[0090]

[0091] Combined with the vehicle speed data, it is converted into the equivalent driving range in the time period t0-t5 through formula (4);

[0092]

[0093] The unit of v is km / h.

[0094] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made according to the structures, features and principles described in the patent scope of the present invention should be included in the scope of the patent application of the present invention.

Claims

1. A power battery pack test system, comprising an environmental simulation system, an air conditioning system, a control and acquisition system, a battery charging and discharging system and a test object, wherein the test object comprises a power battery pack (5), characterized in that: The environmental simulation system comprises a high and low temperature environmental simulation test box (1), a battery pack bracket (2), a fan (3) and a windproof mechanism (4); the battery pack bracket (2) and the fan (3) are arranged in the high and low temperature environmental simulation test box (1); a power battery pack (5) is arranged on the battery pack bracket (2); and the windproof mechanism (4) is arranged on the power battery pack (5); The air conditioning system includes a cooling and heating unit, a water pump, a flow sensor and a temperature sensor, and the control and acquisition system includes a controller, a relay and a host computer; The control acquisition system is provided with a CAN bus and a power harness, and the control acquisition system is respectively connected with the power battery pack (5), the air conditioning system, and the battery charging and discharging system via the CAN bus and the power harness; The control and acquisition system and the fan (3) are connected via a CAN bus; The battery charging and discharging system is connected to the host computer through a CAN bus.

2. A power battery pack test system according to claim 1, characterized in that: The battery pack bracket (2) is a square bracket, the upper end surface of the battery pack bracket (2) is hollowed out, a power battery pack (5) is arranged on the upper end surface of the battery pack bracket (2), an insulating pad (6) made of rubber material is arranged between the upper end surface of the battery pack bracket (2) and the power battery pack (5), a windproof mechanism (4) is arranged on the upper part of the power battery pack (5), the windproof mechanism (4) is a square cover-shaped structure, the windproof mechanism (4) is sleeved on the top and side of the power battery pack (5), a filling layer made of thermal insulation material is arranged between the windproof mechanism (4) and the power battery pack (5), and the filling layer is glued and fixed to the windproof mechanism (4).

3. A power battery pack test system according to claim 1, characterized in that: A fan (3) is arranged on one side of the battery pack bracket (2), and the fan (3) is connected to an external power supply.

4. A power battery pack test system according to claim 1, characterized in that: The coolant water outlet and water return port of the air conditioning system are both provided with pipelines, and the other ends of the pipelines are respectively connected to the water inlet and water outlet of the power battery pack (5).

5. A power battery pack test system according to claim 1, characterized in that: The controller is connected to the host computer via a CAN bus communication.

6. A power battery pack test system according to any one of claims 1 to 5, characterized in that: Including but not limited to applications in power battery pack (5) low temperature heating rate test, power battery pack (5) cooling rate test, power battery pack (5) comprehensive operating condition test and power battery pack (5) thermal management energy consumption test.

7. A power battery pack thermal management energy consumption test method of a power battery pack test system according to any one of claims 1 to 5, characterized in that: include: Step 1: The upper computer controls the battery charging and discharging system to charge the power battery pack (5) until the SOC reaches 100%; Step 2: Adjust the temperature of the high and low temperature environment simulation test box (1) to Tm, and leave it to stand until the temperature of the power battery pack (5) is within Tm±1°C; Step 3: Import the test conditions through the host computer, and input the critical temperature value, coolant target temperature value and flow value for starting and stopping the air conditioning system according to the thermal management strategy; Step 4: Perform the test according to the test conditions. The controller frequently controls the relay to open and close so that the battery charging and discharging system, the cooling and heating unit and the water pump respond to the output. The controller controls the speed of the fan (3) in real time according to the vehicle speed to adjust the wind speed. The data collection cycle is 0.1s to collect data from the power battery pack (5), the air conditioning system, the battery charging and discharging system and the fan (3); Step 5: If the collected temperatures of the power battery pack (5) meet the critical temperature value for stopping the air conditioning system, the controller controls the cooling and heating unit to stop working immediately. When the collected temperatures of the power battery pack (5) meet the critical temperature value for starting the air conditioning system, the controller controls the cooling and heating unit to restart again. Step 6: After the test condition is completed, the number of cycles of the imported test condition can be set through the host computer; Step 7: The host computer analyzes and calculates the effective data collected at each moment and outputs the corresponding thermal management energy consumption data.

8. A power battery pack thermal management energy consumption test method according to claim 7, characterized in that: The test conditions described in step 3 include time, discharge current, feedback current and vehicle speed.

9. A power battery pack thermal management energy consumption test method according to claim 8, characterized in that: The test condition execution test described in step 4 also includes: The discharge current value of the charge and discharge system at each time point should be the difference between the discharge current value in the test condition and the working current value of the cooling and heating unit; The charging current value of the charging and discharging system at each time point should be the sum of the feedback current value in the test condition and the working current value of the cooling and heating unit; During the discharge process of the power battery pack (5), if the maximum allowable discharge current value of the power battery pack (5) is less than the discharge current value in the test condition, the discharge is performed at the maximum allowable discharge current value of the power battery pack (5); During the charging process of the power battery pack (5), if the maximum allowable feedback current value of the power battery pack (5) is less than the feedback current value in the test condition, charging is performed at the maximum allowable feedback current value of the power battery pack (5).

10. A power battery pack thermal management energy consumption test method according to claim 7, characterized in that: The thermal management energy consumption data in step 7 is shown in formulas (1) to (4): P t =U t ×I t (1); Among them, U t is the actual input voltage of the thermal management system at time t, I t is the actual working current, P t is the instantaneous power of the thermal management system at time t; W t =U t ×I t ×0.1(2); Among them, W t is the energy consumed by the thermal management system at time t; Assuming that the working time intervals of the thermal management system during the entire test process are t0-t1, t2-t3 and t4-t5 respectively, the total energy consumption of the thermal management system of the power battery pack (5) during the entire test process is shown in formula (3): Combined with the vehicle speed data, it is converted into the equivalent driving range in the time period t0-t5 through formula (4); The unit of v is km / h.

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