Refrigeration control method and system for plug-in hybrid whole vehicle

Abstract

The invention particularly discloses a plug-in hybrid power whole vehicle refrigeration control method and system. The method comprises the steps that a corresponding relation table of temperature difference values and compressor rotating speeds is set; the difference value between the actual temperature of the battery water inlet and the target temperature of the battery water inlet is obtained, and the battery refrigeration required rotating speed is calculated through the parameters obtained by looking up the corresponding relation table; the difference value between the actual temperature of the evaporator and the target temperature of the evaporator is obtained, and the refrigeration required rotating speed of the passenger compartment is calculated through parameters obtained by looking up the corresponding relation table; and the sum of the battery refrigeration required rotating speed and the passenger compartment refrigeration required rotating speed serves as the rotating speed of a compressor, and speed regulation control over the compressor is conducted. Accurate control over the refrigerating capacity can be improved, and the refrigerating effect is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration control for hybrid vehicles, and more specifically, to a refrigeration control method and system for a plug-in hybrid vehicle. Background Art

[0002] With the development of hybrid vehicles, more and more heating elements, intelligent technologies, and components are added, increasing the system heat load, increasing the system thermal management pressure, and consuming more energy during operation, reducing the maximum driving range of the vehicle. Existing vehicle refrigeration control systems generally use the PI algorithm to control the compressor speed based on the target refrigeration effect and the actual refrigeration effect, without corresponding pretreatment measures and soft start control. Only using PI control will cause the compressor speed to be adjusted too frequently, and there will be a problem that the calculated speed cannot reach the actual control effect, resulting in inaccurate cold quantity distribution and poor refrigeration effect. Therefore, how to accurately control the vehicle refrigeration capacity to achieve effective and energy-saving purposes is of great significance. Summary of the Invention

[0003] The present invention provides a refrigeration control method and system for a plug-in hybrid vehicle, which solves the problem that the existing vehicle refrigeration control for hybrid vehicles adjusts the compressor speed too frequently and is prone to high losses, and can improve the accurate control of refrigeration capacity and enhance the refrigeration effect.

[0004] To achieve the above objectives, the present invention provides the following technical solutions:

[0005] A refrigeration control method for a plug-in hybrid vehicle, comprising:

[0006] Setting a correspondence table between the temperature difference and the compressor speed;

[0007] Obtaining the difference between the actual temperature of the battery water inlet and the target temperature of the battery water inlet, and calculating the battery refrigeration demand speed N1 through the parameters obtained by looking up the correspondence table;

[0008] Obtaining the difference between the actual temperature of the evaporator and the target temperature of the evaporator, and calculating the occupant compartment refrigeration demand speed N2 through the parameters obtained by looking up the correspondence table;

[0009] Taking the sum of the battery refrigeration demand speed N1 and the occupant compartment refrigeration demand speed N2 as the compressor speed to perform compressor speed control.

[0010] Preferably, it further comprises:

[0011] Judging whether there is a cooling demand for the occupant compartment and / or the power battery according to the refrigeration status signals fed back by the air conditioner controller and the battery management controller;

[0012] If both the crew compartment and the power battery have cooling requirements, before starting the compressor, control the condenser fan to start working, control the electric water pump in the battery cooling circulation pipeline to operate at full speed, and control the opening of the battery SOV valve and the crew compartment SOV valve according to the set opening degree;

[0013] Continuously detect the working states of the electric water pump and the condenser fan. If the normal working duration exceeds the set time, determine whether the condition for starting the compressor is met. If so, perform soft start control of the compressor;

[0014] After the compressor starts up, perform speed regulation control of the compressor according to the battery refrigeration demand and / or the crew compartment refrigeration demand.

[0015] Preferably, the speed regulation control of the compressor according to the battery refrigeration demand and / or the crew compartment refrigeration demand includes:

[0016] According to the formula: NS = △T1 × 150, calculate the compressor reference speed NS corresponding to the crew compartment refrigeration, where △T1 is the difference between the actual temperature of the evaporator and the target temperature of the evaporator;

[0017] According to the temperature change range △T2 of the evaporator in the previous setting period, determine whether the compressor speed in the next period increases or remains unchanged, so as to perform corresponding speed regulation control of the compressor for the crew compartment refrigeration.

[0018] Preferably, the determining whether the compressor speed in the next period increases or remains unchanged according to the temperature change range △T2 of the evaporator in the previous setting period includes:

[0019] Set up a correlation table of the compressor speed, △T1, △T2 and the change value of the compressor speed;

[0020] Obtain △T1 and △T2 corresponding to each period, and look up the corresponding change value through the correlation table, and then increase the corresponding change value on the compressor reference speed.

[0021] Preferably, the speed regulation control of the compressor according to the battery refrigeration demand and / or the crew compartment refrigeration demand further includes:

[0022] Determine the compressor reference speed corresponding to the battery refrigeration according to the difference between the actual temperature of the battery water inlet and the target temperature of the battery water inlet;

[0023] According to the calibrated speed change value corresponding to the battery temperature change and the compressor reference speed corresponding to the battery refrigeration, perform speed regulation control of the compressor corresponding to the battery refrigeration.

[0024] The present invention also provides a plug-in hybrid vehicle refrigeration control system that uses the above vehicle refrigeration control method, including: a compressor, an air-conditioning condenser, a first three-way joint, a passenger compartment SOV valve, and a battery SOV valve;

[0025] The output end of the compressor is connected to the input end of the air-conditioning condenser, the output end of the air-conditioning condenser is connected to the first end of the first three-way joint, the second joint of the first three-way joint is connected to the input end of the passenger compartment SOV valve, and the third joint of the first three-way joint is connected to the input end of the battery SOV valve;

[0026] The passenger compartment SOV valve is used to control the refrigerant flow rate in the passenger compartment;

[0027] The battery SOV valve is used to control the refrigerant flow rate to the battery cooling device.

[0028] Preferably, it further includes: an electric water pump, a water storage tank, and a cooler;

[0029] The cooler, the power battery, the water storage tank, and the electric water pump are respectively connected in series on the battery cooling circulation pipeline;

[0030] The refrigerant input end of the cooler is connected to the output end of the battery SOV valve, and the water inlet end of the cooler is connected to the electric water pump through the battery cooling circulation pipeline, so that the refrigerant output by the battery SOV valve exchanges heat with the circulating liquid in the battery cooling circulation pipeline in the cooler to cool the power battery.

[0031] Preferably, it further includes: a second three-way joint;

[0032] The first joint of the second three-way joint is connected to the refrigerant output end of the passenger compartment evaporator, the second joint of the second three-way joint is connected to the refrigerant output end of the cooler, and the third joint of the second three-way joint is connected to the input end of the compressor.

[0033] Preferably, it further includes: a condenser fan;

[0034] The condenser fan is arranged on the air-conditioning condenser to perform air-cooling control on the air-conditioning condenser.

[0035] Preferably, it further includes: a central controller;

[0036] The central controller is respectively signal-connected to the compressor, the condenser fan, the battery SOV valve, and the passenger compartment SOV valve;

[0037] The central controller determines the final compressor speed according to the target evaporator temperature and the target temperature of the battery water inlet, controls the speed regulation of the compressor according to the final compressor speed, and controls the corresponding opening degrees of the battery SOV valve and the passenger compartment SOV valve.

[0038] The present invention provides a refrigeration control method and system for a plug-in hybrid vehicle. By calculating the refrigeration demand speed of the passenger compartment through the actual temperature and the target temperature of the evaporator, and calculating the refrigeration demand speed of the battery through the actual temperature and the target temperature of the battery water inlet, the speed regulation of the compressor is controlled, so as to achieve precise control of the refrigeration capacity required by components, thereby realizing the effect of common refrigeration, and being able to control the power consumption of the compressor to the lowest. It solves the problem that the refrigeration control of the whole vehicle of the existing hybrid vehicle adjusts the compressor speed too frequently, which is easy to cause high losses, can improve the precise control of the refrigeration capacity, and enhance the refrigeration effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below.

[0040] Figure 1 It is a schematic diagram of a refrigeration control method for a plug-in hybrid vehicle provided by the present invention.

[0041] Figure 2 It is a schematic diagram of a refrigeration control system for a plug-in hybrid vehicle provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] In order to enable those skilled in the art to better understand the solutions of the embodiments of the present invention, the embodiments of the present invention will be further described in detail below with reference to the drawings and embodiments.

[0043] Aiming at solving the problem that the refrigeration control of the whole vehicle of the existing hybrid vehicle adjusts the compressor speed too frequently, which is easy to cause high losses, the present invention provides a refrigeration control method and system for a plug-in hybrid vehicle, which solves the problem that the refrigeration control of the whole vehicle of the existing hybrid vehicle adjusts the compressor speed too frequently, which is easy to cause high losses, can improve the precise control of the refrigeration capacity, and enhance the refrigeration effect.

[0044] As Figure 1 shown, a refrigeration control method for a plug-in hybrid vehicle includes:

[0045] S1: Set a correspondence table between the temperature difference and the compressor speed.

[0046] S2: Obtain the difference between the actual temperature and the target temperature of the battery water inlet, and calculate the refrigeration demand speed N1 of the battery by using the parameters obtained by looking up the table in the correspondence table.

[0047] S3: Obtain the difference between the actual temperature and the target temperature of the evaporator, and calculate the refrigeration demand speed N2 of the occupant compartment by looking up the parameters obtained from the corresponding relation table.

[0048] S4: Take the sum of the battery refrigeration demand speed N1 and the occupant compartment refrigeration demand speed N2 as the compressor speed to perform compressor speed regulation control.

[0049] Specifically, after the central controller HCU of the whole vehicle determines that the soft start of the compressor is completed, it enters the compressor speed regulation control: when there is a battery refrigeration demand, the HCU calculates the target speed N1 of the compressor by looking up the parameters obtained from the difference between the actual temperature of the battery water inlet and the target temperature of the water inlet requested by the BMS. When there is a refrigeration demand in the occupant compartment, the HCU calculates the target speed N2 of the compressor by looking up the parameters obtained from the difference between the actual temperature of the evaporator and the target temperature of the evaporator, where the target temperature of the evaporator is related to the ambient temperature. Finally, the compressor speed = battery refrigeration demand speed N1 + occupant compartment refrigeration demand speed N2, and the HCU controls the operation of the compressor according to the final compressor speed.

[0050] Furthermore, if the HCU detects multiple refrigeration demands, it can perform cooling control in descending order of priority: battery forced cooling -> battery normal cooling / occupant compartment cooling.

[0051] Battery forced cooling demand determination: The HCU determines whether the current battery system needs forced cooling according to the highest temperature of the battery cells fed back by the battery, to prevent battery thermal runaway. To avoid repeatedly entering and exiting forced cooling, the temperature setting for exiting forced cooling should be greater than the entering temperature by a certain value.

[0052] This method further includes:

[0053] Judge whether there is a cooling demand for the occupant compartment and / or the power battery according to the refrigeration status signals fed back by the air conditioner controller and the battery management controller.

[0054] If there are cooling demands for both the occupant compartment and the power battery, before starting the compressor, control the condenser fan to start working, control the electric water pump in the battery cooling circulation pipeline to work at full speed, and control the opening of the battery SOV valve and the occupant compartment SOV valve according to the set opening.

[0055] Continuously detect the working states of the electric water pump and the condenser fan. If the normal working duration exceeds the set time, judge whether the condition for starting the compressor is met. If so, perform compressor soft start control.

[0056] After the compressor starts up, perform compressor speed regulation control according to the battery refrigeration demand and / or the occupant compartment refrigeration demand.

[0057] Specifically, further, if the HCU determines that battery conventional cooling / occupant compartment cooling is required, the cooling system needs to be pre-treated before starting the compressor. The pre-treatment includes: 1) controlling the condenser cooling fan to start working; 2) when there is a battery refrigeration demand, controlling the battery thermal management water pump to work at full speed; 3) opening the battery SOV valve / occupant compartment SOV valve. After the HCU controls the above actions, it is necessary to continuously detect the working status of the cooling water pump and the condenser fan. If the normal working duration exceeds a certain time, the compressor start control can be carried out, which can avoid the compressor working in a cooling system failure state.

[0058] At the same time, after the HCU determines that the conditions for starting the compressor are met, soft start control is performed on the compressor to avoid excessive starting power damage to the compressor:

[0059] 1) The soft start time is set to 10 s;

[0060] 2) During the soft start process, the HCU requests the compressor to start and sets the compressor target speed to 1000 rpm.

[0061] Further, the compressor speed regulation control according to the battery refrigeration demand and / or the occupant compartment refrigeration demand includes:

[0062] According to the formula: NS = △T1 × 150, the compressor reference speed NS corresponding to the occupant compartment refrigeration is calculated, where △T1 is the difference between the actual temperature of the evaporator and the target temperature of the evaporator.

[0063] According to the temperature change range △T2 of the evaporator in the previous adjustment period, it is determined whether the compressor speed in the next period increases or remains unchanged, so as to perform corresponding compressor speed regulation control on the occupant compartment refrigeration.

[0064] Further, the determination of whether the compressor speed in the next period increases or remains unchanged according to the temperature change range △T2 of the evaporator in the previous setting period includes:

[0065] Set the correlation table of the compressor speed, △T1, △T2 and the change value of the compressor speed;

[0066] Obtain △T1 and △T2 corresponding to each period, and look up the corresponding change value through the correlation table, and then increase the corresponding change value on the compressor reference speed.

[0067] In practical applications, the compressor speed regulation process is executed once every 5 seconds to avoid frequent adjustments; the maximum speed of the compressor needs to refer to the vehicle speed to avoid poor heat dissipation of the condenser and high working noise of the compressor at low vehicle speeds. The required speed for cabin cooling is first the reference speed NS of the compressor calculated from △T1, and then whether the speed in the next 5-second cycle increases or remains unchanged is determined according to the temperature change amplitude △T2 in the previous 5 seconds.

[0068] In one embodiment, the process of regulating the speed of cabin cooling is as follows:

[0069] According to the formula: NS = △T1 × 150, calculate the reference speed NS of the compressor;

[0070] △T1 = actual evaporator temperature - target evaporator temperature;

[0071] △T2 = evaporator temperature collected last time (5S ago) - current evaporator temperature; where, △T1 and △T2 are positive or negative.

[0072] Establish a correlation table of the compressor speed, △T1, △T2 and the change value of the compressor speed, as shown in Table 1:

[0073]

[0074] The speed regulation control of the compressor is based on △T1 and △T2, look up the corresponding change value in the table, and then determine the final compressor speed in the next cycle according to the reference speed of the compressor and the corresponding change value.

[0075] Further, the compressor speed regulation control according to the battery cooling demand and / or the cabin cooling demand further includes:

[0076] Determine the reference speed of the compressor corresponding to battery cooling according to the difference between the actual temperature of the battery water inlet and the target temperature of the battery water inlet;

[0077] Conduct the compressor speed regulation control corresponding to battery cooling according to the speed change value corresponding to the battery temperature change obtained by calibration and the reference speed of the compressor corresponding to battery cooling.

[0078] Further, if there is an uneven distribution of cooling capacity between the cabin and the battery, the SOV valve can be opened and closed for the side with surplus cooling capacity with reference to the actual cooling effect to increase the side with insufficient cooling capacity.

[0079] It can be seen that the present invention provides a refrigeration control method for a plug-in hybrid vehicle. By calculating the refrigeration demand speed of the passenger compartment through the actual temperature and the target temperature of the evaporator, and calculating the refrigeration demand speed of the battery through the actual temperature and the target temperature of the battery water inlet, the speed of the compressor is controlled accordingly, so as to accurately control the refrigeration capacity required by the components, thereby achieving the effect of common refrigeration and being able to control the power consumption of the compressor to the lowest. It solves the problem that the refrigeration control of the whole vehicle of the existing hybrid vehicle adjusts the speed of the compressor too frequently, which is easy to cause high losses, can improve the accurate control of the refrigeration capacity, and enhance the refrigeration effect.

[0080] Correspondingly, as Figure 2 shown, the present invention also provides a refrigeration control system for a plug-in hybrid vehicle, which uses the above-mentioned refrigeration control method for the whole vehicle and includes: a compressor, an air-conditioning condenser, a first three-way joint T1, a passenger compartment SOV valve V1 and a battery SOV valve V2. The output end of the compressor is connected to the input end of the air-conditioning condenser, the output end of the air-conditioning condenser is connected to the first end of the first three-way joint T1, the second joint of the first three-way joint T1 is connected to the input end of the passenger compartment SOV valve, and the third joint of the first three-way joint T1 is connected to the input end of the battery SOV valve. The passenger compartment SOV valve V1 is used to control the refrigerant flow rate of the passenger compartment; the battery SOV valve V2 is used to control the refrigerant flow rate of the battery cooling device.

[0081] The system further includes: an electric water pump P1, a water storage tank 12 and a cooler 11; the cooler 11, a power battery, the water storage tank 12 and the electric water pump P1 are respectively connected in series on the battery cooling circulation pipeline; the refrigerant input end of the cooler is connected to the output end of the battery SOV valve V2, and the water inlet end of the cooler 11 is connected to the electric water pump through the battery cooling circulation pipeline, so that the refrigerant output by the battery SOV valve V2 exchanges heat with the circulating liquid in the battery cooling circulation pipeline in the cooler to refrigerate the power battery.

[0082] The system further includes: a second three-way joint T2; the first joint of the second three-way joint T2 is connected to the refrigerant output end of the passenger compartment evaporator, the second joint of the second three-way joint T2 is connected to the refrigerant output end of the cooler, and the third joint of the second three-way joint T2 is connected to the input end of the compressor.

[0083] The system further includes: a condenser fan F1; the condenser fan F1 is arranged on the air-conditioning condenser to perform air-cooling control on the air-conditioning condenser.

[0084] The system further includes: a central controller; the central controller is respectively connected to the compressor, the condenser fan F1, the battery SOV valve V2, and the occupant compartment SOV valve V1 in a signal connection manner; the central controller determines the final compressor speed according to the target evaporator temperature and the target temperature of the battery water inlet, and controls the compressor to adjust its speed according to the final compressor speed, and controls the corresponding opening degrees of the battery SOV valve and the occupant compartment SOV valve.

[0085] It can be seen that the present invention provides a plug-in hybrid vehicle refrigeration control system, which controls the refrigerant flow rates of the occupant compartment and the battery cooler through the occupant compartment SOV valve and the battery SOV valve to achieve precise control of the refrigeration capacity, so as to achieve the effect of common refrigeration. The refrigeration demand speed of the occupant compartment is calculated through the actual temperature and the target temperature of the evaporator, and the refrigeration demand speed of the battery is calculated through the actual temperature and the target temperature of the battery water inlet. Furthermore, the speed of the compressor is controlled, and the power consumption of the compressor can be controlled to the lowest. It solves the problem that the existing hybrid vehicle refrigeration control adjusts the compressor speed too frequently, which is easy to cause high losses, can improve the precise control of the refrigeration capacity, and enhance the refrigeration effect.

[0086] The above has detailed the structure, features and function effects of the present invention according to the illustrated embodiments. The above is only the preferred embodiment of the present invention, but the present invention is not limited to the implementation scope shown in the drawings. Any changes made according to the concept of the present invention, or modified into equivalent embodiments with equivalent changes, still within the spirit covered by the specification and the drawings, should be within the protection scope of the present invention.

Claims

1. A plug-in hybrid vehicle refrigeration control method, characterized in that: include: Set the corresponding relationship table between temperature difference and compressor speed; Obtain the difference between the actual temperature of the battery water inlet and the target temperature of the battery water inlet, and calculate the battery cooling demand speed N1 by looking up the parameters obtained in the corresponding relationship table; Obtaining the difference between the actual evaporator temperature and the target evaporator temperature, and calculating the required speed N2 of passenger compartment cooling by looking up the parameters obtained by the corresponding relationship table; The sum of the battery cooling demand speed N1 and the passenger compartment cooling demand speed N2 is used as the compressor speed to perform compressor speed control.

2. The plug-in hybrid vehicle cooling control method according to claim 1, characterized in that: Also includes: According to the cooling status signals fed back by the air conditioning controller and the battery management controller, it is determined whether the passenger compartment and / or the power battery need to be cooled; If both the passenger compartment and the power battery need to be cooled, the condenser fan is controlled to start before the compressor is turned on, the electric water pump in the battery cooling circulation pipeline is controlled to work at full speed, and the battery SOV valve and the passenger compartment SOV valve are controlled to open according to the set opening; Continuously detecting the working status of the electric water pump and the condenser fan, and if the normal working duration exceeds the set time, determining whether the compressor start-up condition is met, and if so, performing the compressor soft start control; After the compressor is started, the compressor speed is controlled according to the battery cooling demand and / or the passenger compartment cooling demand.

3. The plug-in hybrid vehicle refrigeration control method according to claim 2, characterized in that: The compressor speed control according to the battery cooling demand and / or the passenger compartment cooling demand includes: The compressor reference speed NS corresponding to the passenger compartment cooling is calculated according to the formula: NS=△T1×150, where △T1 is the difference between the actual evaporator temperature and the target evaporator temperature; Based on the temperature change amplitude △T2 of the evaporator in the previous setting cycle, it is determined whether the compressor speed in the next cycle will increase or remain unchanged, so as to perform corresponding compressor speed control for passenger compartment cooling.

4. The plug-in hybrid vehicle refrigeration control method according to claim 3, characterized in that: The method of determining whether the compressor speed in the next cycle is increased or kept unchanged according to the temperature change amplitude ΔT2 of the evaporator in the previous set cycle includes: Set up a correlation table between compressor speed, △T1, △T2 and the change value of compressor speed; The ΔT1 and ΔT2 corresponding to each cycle are obtained, and the corresponding change value is obtained by looking up the association table, and then the corresponding change value is added to the reference speed of the compressor.

5. The plug-in hybrid vehicle refrigeration control method according to claim 4, characterized in that: The compressor speed control according to the battery cooling demand and / or the passenger compartment cooling demand also includes: Determine the reference speed of the compressor corresponding to the battery cooling according to the difference between the actual temperature of the battery water inlet and the target temperature of the battery water inlet; The speed control of the compressor corresponding to the battery cooling is performed according to the rotational speed change value corresponding to the battery temperature change obtained by calibration and the reference rotational speed of the compressor corresponding to the battery cooling.

6. A plug-in hybrid vehicle refrigeration control system, using the vehicle refrigeration control method according to any one of claims 1 to 5, characterized in that: include: Compressor, air conditioning condenser, first three-way connector, passenger compartment SOV valve and battery SOV valve; The compressor output end is connected to the input end of the air conditioning condenser, the output end of the air conditioning condenser is connected to the first end of the first three-way joint, the second joint of the first three-way joint is connected to the input end of the passenger compartment SOV valve, and the third joint of the first three-way joint is connected to the input end of the battery SOV valve; The passenger compartment SOV valve is used to control the refrigerant flow in the passenger compartment; The battery SOV valve is used to control the flow of refrigerant to the battery cooling equipment.

7. The plug-in hybrid vehicle refrigeration control system according to claim 6, characterized in that: Also includes: electric water pumps, storage tanks and coolers; The cooler, the power battery, the water storage tank and the electric water pump are respectively arranged in series on the battery cooling circulation pipeline; The refrigerant input end of the cooler is connected to the output end of the battery SOV valve, and the water inlet end of the cooler is connected to the electric water pump through a battery cooling circulation pipeline, so that the refrigerant output by the battery SOV valve exchanges heat with the circulating fluid in the battery cooling circulation pipe in the cooler to cool the power battery.

8. The plug-in hybrid vehicle refrigeration control system according to claim 7, characterized in that: Also includes: Second three-way connector; The first connector of the second three-way connector is connected to the refrigerant output end of the passenger compartment evaporator, the second connector of the second three-way connector is connected to the refrigerant output end of the cooler, and the third connector of the second three-way connector is connected to the input end of the compressor.

9. The plug-in hybrid vehicle refrigeration control system according to claim 8, characterized in that: Also includes: Condenser fan; The condenser fan is arranged on the air-conditioning condenser to perform air-cooling control on the air-conditioning condenser.

10. The plug-in hybrid vehicle refrigeration control system according to claim 9, characterized in that: Also includes: Central controller; The central controller is respectively connected to the compressor, the condenser fan, the battery SOV valve and the passenger compartment SOV valve by signal; The central controller determines a final compressor speed according to a target evaporator temperature and a target battery water inlet temperature, controls the compressor to adjust speed according to the final compressor speed, and controls corresponding openings of the battery SOV valve and the passenger compartment SOV valve.

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