Instantaneous efficiency optimal control method for aviation parallel hybrid power system

Abstract

According to the instantaneous efficiency optimal control method for the aviation parallel hybrid power system, transfer of an engine working point and optimization of the system working efficiency can be achieved on the basis that the parallel hybrid power system can work in an electric or power generation mode through an electric motor / a power generator. At a certain rotating speed, when the power of an engine is greater than the power required by a propeller, considering that the current charging electric energy is output as mechanical work in the future, and dividing the fuel consumption in unit time by the total useful power to obtain an equivalent fuel consumption rate in a charging state; when the power of the engine is smaller than the power required by the propeller, the power difference value is supplemented for the power consumption of the motor, the current power consumption of the motor is considered as the average equivalent fuel consumption in the early charging state, and the equivalent fuel consumption rate in the discharging state is obtained by dividing the equivalent fuel consumption in unit time by the total useful power; the equivalent fuel consumption rate of the system at the current rotating speed can be obtained in the power generation or power consumption stage, and the engine power corresponding to the minimum value in the equivalent fuel consumption rate curve is the optimal engine power with the optimal instantaneous efficiency of the system in the current state; and the power distribution of the engine and the electric motor / generator is determined to be the instantaneous efficiency optimal power distribution of the parallel hybrid power system in the current state.

Description

Technical Field

[0001] The invention relates to the field of aviation hybrid power systems, and in particular to an instantaneous efficiency optimal control method for an aviation parallel hybrid power system. Background Art

[0002] For the energy management strategy of aviation parallel hybrid power system, in order to give full play to the respective advantages of the engine and electric / generator, coordinate the distribution of power sources, optimize fuel efficiency and reduce emissions, an effective energy management strategy needs to be formulated. Energy management strategies are rule-based energy management strategies and optimization-based energy management strategies. The rule-based strategy is easy to implement, so this method is mainly used in engineering; however, the rule-based control method mainly takes the engine working near the ideal operating curve as the main control target to achieve engine efficiency optimization, but this method does not take into account the loss of secondary energy in the electrical system, so this method cannot achieve the optimization of the system's instantaneous efficiency. At present, there is no optimal control method for the system's instantaneous efficiency that takes into account the loss of secondary energy in the electrical system for aviation parallel hybrid power system.

[0003] This patent analyzes the system equivalent fuel consumption rate of the parallel hybrid system under different power generation or power consumption states corresponding to different engine powers while determining the required propeller speed and required power, and obtains the system equivalent fuel consumption rate curve that changes with the engine power in the current state and the minimum equivalent fuel consumption rate (i.e., the system instantaneous efficiency optimal working point). According to the engine power corresponding to the minimum system equivalent fuel consumption rate, the engine and electric / generator power distribution under the current state system instantaneous efficiency optimal control situation is determined, thereby achieving the system instantaneous efficiency optimal control in the current state. Summary of the invention

[0004] In order to solve the control problem of simple and efficient energy management and instantaneous efficiency optimization of aviation parallel hybrid power system, the present invention proposes an optimal control method for instantaneous efficiency of aviation parallel hybrid power system.

[0005] The purpose of the present invention is achieved through the following technical solutions.

[0006] The present invention discloses an instantaneous efficiency optimal control method for an aviation parallel hybrid power system, comprising the following steps:

[0007] Step 1: The aircraft dynamics model can be established according to the principles of flight dynamics. The propeller model can be established based on the test data such as the power and thrust of the propeller at different pitch angles, advance ratios, altitudes, speeds and rotation speeds obtained from the test. The required propulsion power of the aircraft under certain flight conditions is solved according to the flight mission profile and the aircraft dynamics model. The propulsion power is provided by the propeller, so the required propulsion power is transmitted to the propeller model.

[0008] Step 2: According to the propeller model, the input interface information is mainly propeller speed n, pitch angle, altitude and flight speed. Among the above demand information, only n is unknown when determining the flight time. This paper adopts the Newton iteration method, gives n an initial value, and uses the difference between the required propulsion power and the propeller model output propulsion power as the iterative solution function to iteratively solve n under the current aircraft demand. After n is determined, the propeller load demand power P at the current moment can be determined. pro And other information; the Newton iteration formula is:

[0009]

[0010] Where n k+1 With n k Respectively represent the propeller speed before and after iteration, g(n k ) represents the propeller model function, g′(n k ) represents the derivative of the propeller model function;

[0011] Step 3: According to the engine fuel consumption rate f is related to the engine power P eng and engine speed W eng The engine fuel consumption rate can generally be expressed as f(P eng ,W eng ), f(P eng ,W eng )General form:

[0012]

[0013] In the formula, α 2 , α 1 , α 0 Yes and W eng Correlation coefficient; f(P eng ,W eng ) is smaller, indicating that the corresponding working point system has higher working efficiency;

[0014] Step 4: According to n and P pro Considering the efficiency loss caused by the secondary energy conversion of the electric system charging and discharging, the working power P of the electric / generator can be changed. mot Move the engine operating point, thereby changing the system efficiency, where P pro The balance constraint needs to be met, and each component must also meet certain power constraints:

[0015]

[0016] P eng =P pro +P mot(4)

[0017] P mot,min ≤P mot ≤P mot,max (5)

[0018] P bat,min ≤P bat ≤P bat,max (6)

[0019] P min =max{P pro -P mot,max ,P pro -P bat,max η disc η mot ,P eng,min} (7)

[0020] P max =min{P pro -P mot,min ,P pro -P bat,min η gen η cha ,P eng,max} (8)

[0021] P min ≤P eng ≤P max (9)

[0022] Where τ is the reduction ratio from engine to propeller, P mot is the motor / generator working power, P mot,min is the maximum power generation power of the motor / generator (negative value in power generation state), P mot,max is the maximum electric working power of the motor / generator (positive value in electric state), P bat is the battery operating power, P bat,min is the maximum charging power of the battery (the charging state is a negative value), P bat,max is the maximum discharge working power of the battery (discharge state is positive), P eng,min is the minimum working power of the engine in the current state, P eng,max is the maximum working power of the engine in the current state, η gen is the mechanical efficiency of the motor / generator when generating electricity, η cha is the battery charging efficiency, η disc is the battery discharge efficiency, η mot P is the mechanical efficiency of the electric / generator consuming electricity to do work. min In order to comprehensively consider the actual minimum power of the engine, P maxTo comprehensively consider the actual maximum operating power of the engine;

[0023] Step 5: Determine P according to the parallel hybrid system pro The system efficiency can be changed by the participation of the motor / generator. Select W eng A certain engine power P under eng,i , P eng,i The value range is [P min ,P max ], at this time the motor / generator working power is P mot,i , when P eng,i ≥P pro When the electric motor / generator generates and stores electrical energy, the stored electrical energy will be output as useful work in the future in the form of mechanical work. mot,i It will go through four stages: electric / generator power generation, battery charging, future battery discharge, and future electric / generator power consumption and work. The future battery discharge efficiency takes its average efficiency η disc,avg , the future electric / generator power consumption efficiency takes its average efficiency as η mot,avg , define the total energy conversion efficiency of the four stages as η all , current W eng and P eng,i The equivalent fuel consumption rate Ef of the system cha / disc,i = Total equivalent fuel consumed per unit time divided by total useful power, state of charge Ef cha / disc,i The calculation formula is:

[0024]

[0025] η all =η gen η cha η disc,avg η mot,avg (11)

[0026] Step 6: Determine P according to the parallel hybrid system pro The system efficiency can be changed by the participation of the motor / generator. The motor / generator output P mot,i When supplementing power demand, P mot,i The energy consumed by the electric motor / generator can be converted into fuel by converting the electric energy stored in the previous electric motor / generator. Its equivalent fuel consumption rate is the average equivalent fuel consumption rate Ef of the system's previous charging. cha,avg , in the early stage of power generation (a certain engine power generation power P eng,j Greater than or equal to P pro When), the calculation formula is:

[0027]

[0028] Where, t j Ef is the cumulative operation time of the corresponding working point in the previous power generation. cha / disc,j is the system equivalent fuel consumption rate of the corresponding working point of the previous power generation; therefore, when P eng,i <P pro When the system equivalent fuel consumption rate is the total equivalent fuel consumed per unit time divided by the total useful power, the power consumption state Ef cha / disc,i The calculation formula is:

[0029]

[0030] Step 7: Derived from the constraints that each component of the parallel hybrid system needs to meet through step 4, the calculation formula of the equivalent fuel consumption rate of the system in the charging state derived from step 5, and the calculation formula of the equivalent fuel consumption rate of the system in the power consumption state derived from step 6, according to n and P pro , by [P min ,P max ]Traverse P in the interval eng,i Multiple discrete points of each P eng,i Corresponding to Ef in step 5 or step 6 cha / disc,i , and finally the summation can get the current n and P pro NextEf cha / disc , Ef cha / disc The engine power corresponding to the minimum value is the optimal engine power P in the current state. eng,opt , that is, the power distribution between the engine and the electric / generator is the instantaneous efficiency optimal power distribution of the parallel hybrid system in the current state. The objective function is shown in formula (15):

[0031]

[0032] In summary, the optimal control method for the instantaneous efficiency of the parallel hybrid power system in the current state is confirmed. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In the accompanying drawings, Figure 1 The specific implementation steps of the invention content "A method for optimizing instantaneous efficiency of an aviation parallel hybrid power system" are described. Figure 2 The schematic diagram of the example "equivalent fuel consumption rate curve under a certain required propeller speed and required power" in the invention content is described. Figure 3 An example "full flight mission profile" diagram is described in the Summary of the Invention. DETAILED DESCRIPTION

[0034] Technical solution:

[0035] This embodiment provides an optimal control method for instantaneous efficiency of an aviation parallel hybrid power system, comprising the following steps:

[0036] Step 1: The aircraft dynamics model can be established according to the principles of flight dynamics. The propeller model can be established based on the test data such as the power and thrust of the propeller at different pitch angles, advance ratios, altitudes, speeds and rotation speeds obtained from the test. The required propulsion power of the aircraft under certain flight conditions is solved according to the flight mission profile and the aircraft dynamics model. The propulsion power is provided by the propeller, so the required propulsion power is transmitted to the propeller model;

[0037] Step 2: According to the propeller model, the input interface information is mainly propeller speed n, pitch angle, altitude and flight speed. Among the above demand information, only n is unknown when determining the flight time. This paper adopts the Newton iteration method, gives n an initial value, and uses the difference between the required propulsion power and the propeller model output propulsion power as the iterative solution function to iteratively solve n under the current aircraft demand. After n is determined, the propeller load demand power P at the current moment can be determined. pro And other information; the Newton iteration formula is:

[0038]

[0039] Where n k+1 With n k Respectively represent the propeller speed before and after iteration, g(n k ) represents the propeller model function, g′(n k ) represents the derivative of the propeller model function;

[0040] Step 3: According to the engine fuel consumption rate f is related to the engine power P eng and engine speed W eng The engine fuel consumption rate can generally be expressed as f(P eng ,W eng ), f(P eng ,W eng )General form:

[0041]

[0042] In the formula, α 2 , α 1 , α 0 Yes and W eng Correlation coefficient; f(P eng ,W eng ) is smaller, indicating that the corresponding working point system has higher working efficiency;

[0043] Step 4: According to n and P proConsidering the efficiency loss caused by the secondary energy conversion of the electric system charging and discharging, the working power P of the electric / generator can be changed. mot Move the engine operating point, thereby changing the system efficiency, where P pro The balance constraint needs to be met, and each component must also meet certain power constraints:

[0044]

[0045] P eng =P pro +P mot (4)

[0046] P mot,min ≤P mot ≤P mot,max (5)

[0047] P bat,min ≤P bat ≤P bat,max (6)

[0048] P min =max{P pro -P mot,max ,P pro -P bat,max η disc η mot ,P eng,min} (7)

[0049] P max =min{P pro -P mot,min ,P pro -P bat,min η gen η cha ,P eng,max} (8)

[0050] P min ≤P eng ≤P max (9)

[0051] Where τ is the reduction ratio from engine to propeller, P mot is the motor / generator working power, P mot,min is the maximum power generation power of the motor / generator (negative value in power generation state), P mot,max is the maximum electric working power of the motor / generator (positive value in electric state), P bat is the battery operating power, P bat,min is the maximum charging power of the battery (the charging state is a negative value), P bat,max is the maximum discharge working power of the battery (discharge state is positive), Peng,min is the minimum working power of the engine in the current state, P eng,max is the maximum working power of the engine in the current state, η gen is the mechanical efficiency of the motor / generator when generating electricity, η cha is the battery charging efficiency, η disc is the battery discharge efficiency, η mot P is the mechanical efficiency of the electric / generator consuming electricity to do work. min In order to comprehensively consider the actual minimum power of the engine, P max To comprehensively consider the actual maximum operating power of the engine;

[0052] Step 5: Determine P according to the parallel hybrid system pro The system efficiency can be changed by the participation of the motor / generator. Select W eng A certain engine power P under eng,i , P eng,i The value range is [P min ,P max ], at this time the motor / generator working power is P mot,i , when P eng,i ≥P pro When the electric motor / generator generates and stores electrical energy, the stored electrical energy will be output as useful work in the future in the form of mechanical work. mot,i It will go through four stages: electric / generator power generation, battery charging, future battery discharge, and future electric / generator power consumption and work. The future battery discharge efficiency takes its average efficiency η disc,avg , the future electric / generator power consumption efficiency takes its average efficiency as η mot,avg , define the total energy conversion efficiency of the four stages as η all , current W eng and P eng,i The equivalent fuel consumption rate Ef of the system cha / disc,i = Total equivalent fuel consumed per unit time divided by total useful power, state of charge Ef cha / disc,i The calculation formula is:

[0053]

[0054] η all =η gen η cha η disc,avg η mot,avg (11)

[0055] Step 6: Determine P according to the parallel hybrid system pro The system efficiency can be changed by the participation of the motor / generator. The motor / generator output P mot,i When supplementing power demand, Pmot,i The energy consumed by the electric motor / generator can be converted into fuel by converting the electric energy stored in the previous electric motor / generator. Its equivalent fuel consumption rate is the average equivalent fuel consumption rate Ef of the system's previous charging. cha,avg , in the early stage of power generation (a certain engine power generation power P eng,j Greater than or equal to P pro When), the calculation formula is:

[0056]

[0057] Where, t j Ef is the cumulative operation time of the corresponding working point in the previous power generation. cha / disc,j is the system equivalent fuel consumption rate of the corresponding working point of the previous power generation; therefore, when P eng,i <P pro When the system equivalent fuel consumption rate is the total equivalent fuel consumed per unit time divided by the total useful power, the power consumption state Ef cha / disc,i The calculation formula is:

[0058]

[0059] Step 7: Derived from the constraints that each component of the parallel hybrid system needs to meet through step 4, the calculation formula of the equivalent fuel consumption rate of the system in the charging state derived from step 5, and the calculation formula of the equivalent fuel consumption rate of the system in the power consumption state derived from step 6, according to n and P pro , by [P min ,P max ]Traverse P in the interval eng,i Multiple discrete points of each P eng,i Corresponding to Ef in step 5 or step 6 cha / disc,i , and finally the summation can get the current n and P pro NextEf cha / disc , Ef cha / disc The engine power corresponding to the minimum value is the optimal engine power P in the current state. eng,opt , that is, the power distribution between the engine and the electric / generator is the instantaneous efficiency optimal power distribution of the parallel hybrid system in the current state. The objective function is shown in formula (15):

[0060]

[0061] In summary, the optimal control method for the instantaneous efficiency of the parallel hybrid power system in the current state is confirmed.

[0062] Figure 2An example in a specific implementation is described, which shows an equivalent fuel consumption rate curve under a certain propeller required speed and required power, and the system equivalent fuel consumption rate curve in the current state is obtained according to the current required speed and power. From the system equivalent fuel consumption rate curve, it can be seen that the system instantaneous efficiency in the current state is optimal. The engine power is 36.6kW, and the electric / generator power is 0kW.

[0063] In this implementation case, the main parameters of the parallel hybrid aircraft are shown in Table 1 below:

[0064] Table 1 Main parameters of parallel hybrid aircraft

[0065]

[0066] See also Figure 3 As shown in FIG. 2 , it is a mission profile diagram of the entire flight process of this implementation case. According to this mission profile, the traditional IOL strategy and the energy management strategy of the present invention are respectively used for simulation comparison. The simulation results are summarized in Table 2. It can be seen from the simulation results that under the energy management strategy of the present invention, the fuel consumption is smaller and the system efficiency is higher, which means that the strategy of the present invention has a better energy-saving effect and can save more fuel.

[0067] Table 2 Comparison of simulation results of the energy management strategy implemented by the present invention and the existing IOL strategy

[0068] index IOL The present invention Fuel consumption 9.8kg 9.1kg System efficiency 18.2％ 22.1％

[0069] Compared with the prior art, the aviation parallel hybrid power system instantaneous efficiency optimal control method obtained in this embodiment can help the aviation parallel hybrid power system achieve instantaneous efficiency optimal control.

Claims

1. An optimal control method for instantaneous efficiency of an aviation parallel hybrid system: Step 1: The aircraft dynamics model can be established according to the principles of flight dynamics. The propeller model can be established based on the test data such as the power and thrust of the propeller at different pitch angles, advance ratios, altitudes, speeds and rotation speeds obtained from the test. The required propulsion power of the aircraft under certain flight conditions is solved according to the flight mission profile and the aircraft dynamics model. The propulsion power is provided by the propeller, so the required propulsion power is transmitted to the propeller model. Step 2: According to the propeller model, the input interface information is mainly propeller speed n, pitch angle, altitude and flight speed. Among the above demand information, only n is unknown when determining the flight time. This paper adopts the Newton iteration method, gives n an initial value, and uses the difference between the required propulsion power and the propeller model output propulsion power as the iterative solution function to iteratively solve n under the current aircraft demand. After n is determined, the propeller load demand power P at the current moment can be determined. pro and other information; The Newton iteration formula is: Where n k+1 With n k Respectively represent the propeller speed before and after iteration, g(n k ) represents the propeller model function, g′(n k ) represents the derivative of the propeller model function; Step 3: According to the engine fuel consumption rate f is related to the engine power P eng and engine speed W eng The engine fuel consumption rate can generally be expressed as f(P eng ,W eng ), f(P eng ,W eng )General form: In the formula, α2, α1, α0 are related to W eng Correlation coefficient; f(P eng ,W eng ) is smaller, indicating that the corresponding working point system has higher working efficiency; Step 4: According to n and P pro Considering the efficiency loss caused by the secondary energy conversion of the electric system charging and discharging, the working power P of the electric / generator can be changed. mot Move the engine operating point, thereby changing the system efficiency, where P pro The balance constraint needs to be met, and each component must also meet certain power constraints: P eng =P pro +P mot (4) P mot,min ≤P mot ≤P mot,max (5) P bat,min ≤P bat ≤P bat,max (6) P min =max{P pro -P mot,max ,P pro -P bat,max η disc η mot ,P eng,min } (7) P max =min{P pro -P mot,min ,P pro -P bat,min or gen or cha ,P eng,max } (8) P min ≤P eng ≤P max (9) Where τ is the reduction ratio from engine to propeller, P mot is the motor / generator working power, P mot,min is the maximum power generation power of the motor / generator (negative value in power generation state), P mot,max is the maximum electric working power of the motor / generator (positive value in electric state), P bat is the battery operating power, P bat,min is the maximum charging power of the battery (the charging state is a negative value), P bat,max is the maximum discharge working power of the battery (discharge state is positive), P eng,min is the minimum working power of the engine in the current state, P eng,max is the maximum working power of the engine in the current state, η gen is the mechanical efficiency of the motor / generator when generating electricity, η cha is the battery charging efficiency, η disc is the battery discharge efficiency, η mot P is the mechanical efficiency of the electric / generator consuming electricity to do work. min In order to comprehensively consider the actual minimum power of the engine, P max To comprehensively consider the actual maximum operating power of the engine; Step 5: Determine P according to the parallel hybrid system pro The system efficiency can be changed by the participation of the motor / generator. Select W eng A certain engine power P under eng,i , P eng,i The value range is [P min ,P max ], at this time the motor / generator working power is P mot,i , when P eng,i ≥P pro When the electric motor / generator generates and stores electrical energy, the stored electrical energy will be output as useful work in the future in the form of mechanical work. mot,i It will go through four stages: electric / generator power generation, battery charging, future battery discharge, and future electric / generator power consumption and work. The future battery discharge efficiency takes its average efficiency η disc,avg , the future electric / generator power consumption efficiency takes its average efficiency as η mot,avg , define the total energy conversion efficiency of the four stages as η all , current W eng and P eng,i The equivalent fuel consumption rate Ef of the system cha / disc,i = Total equivalent fuel consumed per unit time divided by total useful power, state of charge Ef cha / disc,i The calculation formula is: or all =the gen or cha or disc,avg or mot,avg (11) Step 6: Determine P according to the parallel hybrid system pro The system efficiency can be changed by the participation of the motor / generator. The motor / generator output P mot,i When supplementing power demand, P mot,i The energy consumed by the electric motor / generator can be converted into fuel by converting the electric energy stored in the previous electric motor / generator. Its equivalent fuel consumption rate is the average equivalent fuel consumption rate Ef of the system's previous charging. cha,avg , in the early stage of power generation (a certain engine power generation power P eng,j Greater than or equal to P pro When), the calculation formula is: Where, t j Ef is the cumulative operation time of the corresponding working point in the previous power generation. cha / disc,j is the system equivalent fuel consumption rate of the corresponding working point of the previous power generation; therefore, when P eng,i <P pro When the system equivalent fuel consumption rate is the total equivalent fuel consumed per unit time divided by the total useful power, the power consumption state Ef cha / disc,i The calculation formula is: Step 7: Derived from the constraints that each component of the parallel hybrid system needs to meet through step 4, the calculation formula of the equivalent fuel consumption rate of the system in the charging state derived from step 5, and the calculation formula of the equivalent fuel consumption rate of the system in the power consumption state derived from step 6, according to n and P pro , by [P min ,P max ]Traverse P in the interval eng,i Multiple discrete points of each P eng,i Corresponding to Ef in step 5 or step 6 cha / disc,i , and finally the summation can get the current n and P pro NextEf cha / disc , Ef cha / disc The engine power corresponding to the minimum value is the optimal engine power P in the current state. eng,opt , that is, the power distribution between the engine and the electric / generator is the instantaneous efficiency optimal power distribution of the parallel hybrid system in the current state. The objective function is shown in formula (15): In summary, the optimal control method for the instantaneous efficiency of the parallel hybrid power system in the current state is confirmed.

2. The method for optimizing instantaneous efficiency of an aviation parallel hybrid power system according to claim 1, characterized in that The modeling method of the propeller backward model described in step 4 is characterized in that: when the required propulsion power of the propeller is known, the Newton iteration method can be used to obtain the unknown information of the propeller at the current moment, and an initial value of n is given. The difference between the required propulsion power and the propeller model output propulsion power is used as an iterative solution function, and n, P are iteratively solved. pro And other information.

3. The method for optimizing instantaneous efficiency of an aviation parallel hybrid power system according to claim 1, characterized in that The calculation of the system equivalent fuel consumption rate under the charging state described in step 5 is characterized in that: under a certain n, when P eng,i ≥P pro When the motor / generator consumes P mot,i Used to generate electricity and store it, and output it in the form of mechanical work in the future, where P mot,i After four stages of electric / generator power generation, battery charging, future battery discharge, and future electric / generator power consumption, the total energy conversion efficiency is η all , from the current state W eng , P eng,i and f(P eng,i ,W eng ) can be used to calculate the fuel consumption per unit time. The useful work generated by the energy consumption of the engine is the sum of the required work of the propeller and the effective mechanical work output by the future motor. The Ef under the current charging state can be calculated by dividing the fuel consumption per unit time by the total useful power. cha / disc,i .

4. The method for optimizing instantaneous efficiency of an aviation parallel hybrid power system according to claim 1, characterized in that The calculation of the system equivalent fuel consumption rate under the power consumption state described in step 6 is characterized in that: under a certain n, when P eng,i <P pro , need to output P mot,i To make up for the remaining load power demand, considering that P mot,i The power generated by the fuel consumed in the previous period is converted into power by calculating Ef cha,avg , you can get the current output P mot,i The equivalent fuel consumption rate corresponding to the consumption of electric energy is the sum of the fuel consumption per unit time of the engine and the equivalent fuel consumption generated by the power consumption per unit time of the motor, which is the total equivalent fuel consumption per unit time of the system in the electric state. The total equivalent fuel consumption per unit time is divided by the useful power to obtain Ef under the current system power consumption state. cha / disc,i .

5. The method for optimizing instantaneous efficiency of an aviation parallel hybrid power system according to claim 1, characterized in that Ef when determining n in step 7 cha / disc Calculation, characterized in that: according to n and P pro , by [P min ,P max ]Traverse P in the interval eng,i Multiple discrete points of each P eng,i The following corresponds to Ef in step 5 or step 6 cha / disc,i , the parallel hybrid system is calculated at the current n and P pro Ef cha / disc , according to Ef cha / disc You can confirm P eng,opt , that is, confirming the optimal power distribution between the engine and the electric / generator, that is, completing the instantaneous efficiency optimal control method of the parallel hybrid system under the corresponding state.

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