High-power hybrid vehicle energy management method considering heat dissipation and energy consumption

Abstract

A high-power hybrid vehicle energy management method considering heat dissipation and energy consumption comprises the steps that the heating value of each component of a power system is calculated, and a heating model is established; establishing a cooling system heat dissipation power model through data fitting by taking the fan air volume and the water pump flow speed as control variables; and obtaining the required power of the whole vehicle by combining with the traction power requirement of the driving module based on a longitudinal kinetic equation, and performing energy management on the basis of the requirement. According to the method, heat dissipation energy consumption of the cooling system is introduced for energy management, and compared with a traditional control strategy formulated based on traction power, the adaptability of the control strategy is enhanced, and the energy consumption economical efficiency of the high-power hybrid power vehicle is improved.

Description

Technical Field

[0001] The invention relates to the field of hybrid vehicle energy management, and in particular to a high-power hybrid vehicle energy management method taking heat dissipation and energy consumption into consideration. Background Art

[0002] Hybrid vehicles combine engines, generators, and energy storage units together. Through good coordinated control between the components, they can give full play to the respective advantages of internal combustion vehicles and pure electric vehicles, effectively improve energy economy, and reduce exhaust emissions.

[0003] When formulating energy management strategies for common small hybrid passenger cars, most of them use traction power as the target power to formulate power allocation strategies due to their small power and low heat dissipation power, without considering the heat dissipation power. This has little effect on the energy economy of the formulated strategy. However, high-power hybrid vehicles have high power demand and correspondingly high heat generation, requiring the cooling system to consume a large amount of power for cooling and heat dissipation. At this time, if only traction power is used as the target power, the target power is quite different from the actual demand power, and the formulated energy management strategy does not match the usage scenario, reducing the energy economy of the vehicle. Summary of the invention

[0004] In order to make the optimized target power close to the actual power and improve the energy consumption economy of high-power hybrid vehicles, the present disclosure provides a high-power hybrid vehicle energy management method taking into account the heat dissipation energy consumption. The method takes into account the heat dissipation energy consumption of the cooling system, establishes a cooling system heat dissipation model through test data fitting and formulas, calculates the heat dissipation power, and uses traction power and heat dissipation power as the total required power to formulate an energy management strategy, thereby improving the energy consumption economy of high-power hybrid vehicles.

[0005] The present invention provides an energy management method for high-power hybrid vehicles that takes into account heat dissipation energy consumption. The method establishes a heat generation model for power system components; selects the heat dissipation power of the radiator as a state variable, and the fan speed and the water pump speed as control variables, and establishes a cooling system heat dissipation model through data fitting; and then establishes a total power demand calculation model for the hybrid vehicle.

[0006] The specific steps include:

[0007] S1, calculate the heat generated by each component of the power system and establish a heat generation model of the power system;

[0008] S2, calculate the heat dissipation power requirement of the cooling system;

[0009] S3, obtaining the power requirement of the entire vehicle based on the heat dissipation power requirement of the cooling system obtained in step S2 and the traction power requirement determined according to the longitudinal dynamics equation;

[0010] S4, performing energy management optimization based on the vehicle power demand obtained in step S3.

[0011] Furthermore, in step S1, the power system heat generation model includes: an engine heat generation model, a motor heat generation model, a battery heat generation model, and other component heat generation models, wherein:

[0012] The engine heating model is:

[0013] Among them, a is the ratio of the heat transferred from the engine to the cooling system to the total heat of the fuel; g e is the fuel consumption rate; P e is the power of the engine; H f The fuel has a low calorific value;

[0014] The motor heating model is: Q2 = P m ·(1-η)

[0015] Among them, P m is the power of the motor; η is the efficiency of the motor;

[0016] The battery heating model is:

[0017] Where R0 is the sum of the ohmic internal resistance and the polarization internal resistance; I is the battery current; T bat is the battery thermodynamic temperature; is the temperature coefficient;

[0018] The heat generated by other heat source components is expressed by constant Q4 through simulation;

[0019] The heat generated by the power system is obtained as follows: Q f =Q1+Q2+Q3+Q4.

[0020] Furthermore, in step S2, the method for calculating the heat dissipation power requirement of the cooling system includes:

[0021] S21, through the test, fitting the water pump speed-coolant flow rate-water pump inlet and outlet pressure difference curve, and then interpolating to obtain the coolant flow rate and the water pump inlet and outlet pressure difference at different water pump speeds;

[0022] The water pump cooling model is:

[0023] Where P m The heat dissipation power of the water pump; w p is the water pump speed; V is the coolant flow rate; H w f is the pressure difference between the inlet and outlet of the pump; e is the pump efficiency, which is taken as a constant;

[0024] S22, assuming that the wind resistance of the heat dissipation flow channel remains unchanged, a fan speed-power-air volume curve is obtained through the fan characteristic curve, and then the fan power and air volume at different fan speeds are obtained through interpolation;

[0025] The fan cooling model is obtained by fitting: P f =P fan (w f ), Q w =Q fan (w f )

[0026] Where P f is the fan cooling power; w f is the fan speed; Q w is the fan air volume;

[0027] Pfan and Qfan represent the functional relationship between fan speed and fan cooling power and between fan speed and air volume, respectively;

[0028] S23, through the test under the specific experimental temperature difference, different coolant flow rate V and air volume Q are fitted w The heat dissipation of the radiator f(V,Q w );

[0029] The heat dissipation model of the radiator is:

[0030] Among them, Q R is the heat dissipation of the radiator; f(V,Q) is the heat dissipation of the radiator under a specific temperature difference obtained in the experiment; V is the coolant flow rate; Q w is the air volume; T cool is the coolant temperature; T air is the air temperature; ΔT is the test temperature difference;

[0031] S24, combining the power system heating model with the cooling system heat dissipation model to make the heat dissipation Q R =Heat value Q f , the heat dissipation is Q R Coolant flow rate V and air volume Q at w ;

[0032] Then, using the water pump cooling model and the fan cooling model, the water pump power P is obtained. m And fan power P f ;

[0033] Finally, the cooling system heat dissipation power requirement is obtained: P s =P m +P f .

[0034] Furthermore, in step S3,

[0035] Among them, m is the mass of the vehicle; g is the acceleration of gravity; f is the rolling resistance; is the slope angle; C d is the drag coefficient; A is the frontal area; a is the acceleration; δ is the rotational mass conversion coefficient; v is the vehicle speed.

[0036] Furthermore, in step S3, the vehicle power requirement P is:

[0037]

[0038] Among them, P s To meet the heat dissipation power requirements.

[0039] The hybrid vehicle to which the above method is applied mainly includes:

[0040] (1) Power module, including engine, generator and energy storage unit. The engine crankshaft is connected to the generator rotor, and the engine can drive the generator rotor to rotate and generate electricity. The energy storage unit can provide electrical energy to the load and can also store the energy output by the engine-generator set;

[0041] (2) The control module allocates power to the power module according to the SOC of the energy storage unit, the total power demand considering the heat dissipation energy consumption, and the control strategy to meet the heat dissipation power and traction power requirements of the cooling system;

[0042] (3) Traction power module, which uses the longitudinal dynamics equation to calculate the traction power;

[0043] The control module calculates the heat dissipation power requirement of the cooling system according to the heat dissipation model and the heat generation model; wherein:

[0044] Heat dissipation model, including fan heat dissipation model, water pump heat dissipation model, and radiator heat dissipation model;

[0045] Heat generation model, including engine heat generation model, motor heat generation model, battery heat generation model, and heat generation models of other heat source components.

[0046] Compared with the prior art, the beneficial effects of the present invention are: (1) by introducing the heat dissipation energy consumption of the cooling system to formulate an energy management strategy, the accuracy of calculating the required power can be effectively improved; (2) the problem that when formulating the energy management strategy in the prior art, the traction required power calculated using the dynamic equation is quite different from the actual required power is solved, thereby improving the effectiveness of the energy management strategy; (3) the energy consumption economy of the hybrid vehicle operation is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present disclosure.

[0048] Figure 1 A flow chart of a method for energy management of a high-power hybrid vehicle considering heat dissipation;

[0049] Figure 2 Schematic diagram of energy management system considering heat dissipation;

[0050] Figure 3 is an exemplary fan power-air volume curve. DETAILED DESCRIPTION

[0051] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0052] The present disclosure proposes an energy management method suitable for high-power hybrid vehicles, which aims to formulate an energy management strategy by introducing the heat dissipation energy consumption of the cooling system to solve the problem that when formulating the energy management strategy, the traction demand power calculated using the dynamic equation is significantly different from the actual demand power.

[0053] According to an exemplary energy management strategy formulation process considering heat dissipation energy consumption according to the present disclosure, as shown in the attached Figure 1 As shown:

[0054] An apparatus according to an exemplary embodiment comprises:

[0055] Step 1: Calculate the heat generated by the engine, motor, battery, and other components.

[0056] (1) The engine heating model is:

[0057] Among them, a is the ratio of the heat transferred from the engine to the cooling system to the total heat of the fuel; g e is the fuel consumption rate; P e is the power of the engine; H f The fuel has a low calorific value;

[0058] (2) Motor heating model: Q2 = P (1-η)

[0059] Where P is the power of the motor; η is the efficiency of the motor.

[0060] (3) The battery heating model is:

[0061] Where R0 is the sum of the ohmic internal resistance and the polarization internal resistance; I is the battery current; T bat is the battery thermodynamic temperature; is the temperature coefficient.

[0062] (4) The heat generated by other heat source components is expressed by the constant Q4 through simulation.

[0063] (5) Calculate the heat generated by the power system: Q f =Q 1+ Q 2+ Q3+Q4

[0064] Vehicle speed affects the power of the engine, motor, and battery, which in turn affects the heat generated by the power system.

[0065] Step 2: Calculate the cooling system heat dissipation power requirements.

[0066] (1) Through experiments, the water pump speed-coolant flow rate-water pump inlet and outlet pressure difference curve is fitted, and then the coolant flow rate and water pump inlet and outlet pressure difference at different water pump speeds can be obtained by interpolation.

[0067] The water pump cooling model is:

[0068] Where P m is the heat dissipation power of the water pump; w p is the water pump speed; V is the coolant flow rate; H w f is the pressure difference between the inlet and outlet of the pump; e is the water pump efficiency, which is taken as a constant; the coolant flow rate and the water pump inlet and outlet pressure difference are obtained by curve interpolation.

[0069] (2) Assuming that the wind resistance of the heat dissipation channel remains unchanged, the fan speed-power-air volume curve can be obtained through the fan characteristic curve, and then the fan power and air volume at different fan speeds can be obtained through interpolation.

[0070] The fan cooling model is: P f =P fan (w f ), Q w =Q fan (w f )

[0071] Where P f is the fan cooling power; w f is the fan speed; Q w It is the fan air volume.

[0072] (3) Through the test under a specific experimental temperature difference, the heat dissipation f(V,Q) of the radiator with different coolant flow rate and air volume is obtained by fitting. w );

[0073] The heat dissipation model of the radiator is:

[0074] Among them, Q R is the heat dissipation of the radiator; f(V,Q) is the heat dissipation of the radiator under a specific temperature difference obtained in the experiment; V is the coolant flow rate; Q w is the air volume; T cool is the coolant temperature; T air is the air temperature; ΔT is the test temperature difference.

[0075] (4) Combine the power system heat model with the cooling system heat dissipation model to make the heat dissipation Q R =Heat value Q f , the heat dissipation is Q R Coolant flow rate and air volume at the time;

[0076] Then the water pump power and fan power are obtained;

[0077] Finally, the cooling system heat dissipation power required P s =P m +P f .

[0078] Step 3: Calculate the traction power and total required power.

[0079] Calculation Model of Total Required Power for Hybrid Electric Vehicles

[0080]

[0081] Among them, m is the mass of the vehicle; g is the acceleration of gravity; f is the rolling resistance; is the slope angle; C d is the drag coefficient; A is the frontal area; a is the acceleration; δ is the rotational mass conversion factor; v is the vehicle speed; P s is the heat dissipation power.

[0082] Step 4: Based on the total power requirement considering the heat dissipation energy consumption, an energy management strategy is formulated using an optimization algorithm.

[0083] As attached Figure 2 As shown, the hybrid vehicle to which the above method is applied mainly includes:

[0084] The power module includes an engine, a generator and an energy storage unit. The engine crankshaft is connected to the generator rotor, and the engine can drive the generator rotor to rotate and generate electricity. The energy storage unit can provide electrical energy to the load and can also store the energy output by the engine-generator set.

[0085] The heating model, including the engine heating model, the motor heating model, the battery heating model, and the heating model of other heat source components, uses corresponding formulas to calculate the heating value.

[0086] The heat dissipation model, including the fan heat dissipation model, the water pump heat dissipation model, and the radiator heat dissipation model, uses corresponding formulas to calculate the heat dissipation.

[0087] The traction power module uses the longitudinal dynamics equation to calculate the traction power.

[0088] The control module distributes power to the power module according to the SOC of the energy storage unit, the total power demand, and the control strategy to meet the heat dissipation power and traction power of the cooling system.

[0089] The above technical scheme is only an exemplary embodiment of the present invention. For those skilled in the art, it is easy to make various types of improvements or modifications based on the application methods and principles disclosed in the present invention, and it is not limited to the method described in the above specific embodiment of the present invention. Therefore, the method described above is only preferred and does not have a restrictive meaning.

Claims

1. A high-power hybrid vehicle energy management method considering heat dissipation and energy consumption, comprising the following steps: S1, calculate the heat generated by each component of the power system and establish a heat generation model of the power system; S2, calculate the heat dissipation power requirement of the cooling system; S3, obtaining the power requirement of the entire vehicle based on the heat dissipation power requirement of the cooling system obtained in step S2 and the traction power requirement determined according to the longitudinal dynamics equation; S4, performing energy management optimization based on the vehicle power demand obtained in step S3.

2. The method according to claim 1, characterized in that: In step S1, the power system heat generation model includes: an engine heat generation model, a motor heat generation model, a battery heat generation model, and other component heat generation models, wherein: The engine heating model is: Among them, a is the ratio of the heat transferred from the engine to the cooling system to the total heat of the fuel; g e is the fuel consumption rate; P e is the power of the engine; H f The fuel has a low calorific value; The motor heating model is: Q2 = P m ·(1-η) Among them, P m is the power of the motor; η is the efficiency of the motor; The battery heating model is: Where R0 is the sum of the ohmic internal resistance and the polarization internal resistance; I is the battery current; T bat is the battery thermodynamic temperature; is the temperature coefficient; The heat generated by other heat source components is expressed by constant Q4 through simulation; The heat generated by the power system is obtained as follows: Q f =Q1+Q2+Q3+Q4.

3. The method according to claim 2, characterized in that In step S2, the cooling system heat dissipation power requirement calculation method includes: S21, through the test, fitting the water pump speed-coolant flow rate-water pump inlet and outlet pressure difference curve, and then interpolating to obtain the coolant flow rate and the water pump inlet and outlet pressure difference at different water pump speeds; The water pump cooling model is: Where P m The heat dissipation power of the water pump; w p is the water pump speed; V is the coolant flow rate; H w f is the pressure difference between the inlet and outlet of the pump; e is the pump efficiency, which is taken as a constant; S22, assuming that the wind resistance of the heat dissipation flow channel remains unchanged, a fan speed-power-air volume curve is obtained through the fan characteristic curve, and then the fan power and air volume at different fan speeds are obtained through interpolation; The fan cooling model is obtained by fitting: P f =P fan (w f ), Q w =Q fan (w f ) Where P f is the fan cooling power; w f is the fan speed; Q w is the fan air volume; Pfan, Qfan represent the functional relationship between fan speed and fan heat dissipation power and between fan speed and air volume, respectively; S23, through the test under the specific experimental temperature difference, different coolant flow rate V and air volume Q are fitted w The heat dissipation of the radiator f(V,Q w ); The heat dissipation model of the radiator is: Among them, Q R is the heat dissipation of the radiator; f(V,Q) is the heat dissipation of the radiator under a specific temperature difference obtained in the experiment; V is the coolant flow rate; Q w is the air volume; T cool is the coolant temperature; T air is the air temperature; ΔT is the test temperature difference; S24, combining the power system heating model with the cooling system heat dissipation model to make the heat dissipation Q R =Heat value Q f , the heat dissipation is Q R Coolant velocity V and air volume Q at w ; Then, using the water pump cooling model and the fan cooling model, the water pump power P is obtained. m And fan power P f ; Finally, the cooling system heat dissipation power requirement is obtained: P s =P m +P f .

4. The method according to any one of claims 1 to 3, characterized in that: In step S3, the Among them, m is the mass of the vehicle; g is the acceleration of gravity; f is the rolling resistance; is the slope angle; C d is the drag coefficient; A is the frontal area; a is the acceleration; δ is the rotational mass conversion coefficient; v is the vehicle speed.

5. The method according to claim 4, characterized in that In step S3, the vehicle power requirement P is: Among them, P s For the heat dissipation power.

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