Optimal control method for electric vehicle range extender

Abstract

The invention relates to an optimal control method for a range extender of an electric vehicle, and designs a multi-stage power following control method suitable for the operation of a range-extended electric vehicle in cities. The control process is as follows: First, according to the current operating conditions of the electric vehicle, determine the working area with the lowest fuel consumption, and select one of the N operating points for matching; determine the current power demand value and actual power value, and adjust the range extender Control the output power, determine the current demand value of the range extender in the static coordinate system, and finally control the working current of the range extender according to the current demand value; based on the switching of the engine at N operating points, the speed point will be switched accordingly , so the output frequency of the generator will also work stably at N frequency points ω according to the change of the rotational speed 1 , ω 2 … ω N . Therefore, the present invention simplifies the coordinate transformation of the control process, and improves the stability, robustness and real-time tracking characteristics of the system.

Description

Technical field: [0001] The invention relates to a hybrid electric vehicle, and further relates to an optimal control method for a range extender of the electric vehicle. Background technique: [0002] In order to overcome the shortcoming of a pure electric vehicle (Electric Vehicle, EV) with insufficient range, more and more types of electric vehicles have been defined and developed. Extended Ranger Electrical Vehicle (EREV) is considered as a low-cost solution. EREV mainly has three structural forms: battery power generation system, fuel cell system, engine and generator combination system. Among them, the engine and generator combined power generation system is the most widely used, and a small generator set is integrated inside it. The structural diagram of the power system is shown in the attachment figure 1 shown. The difference between EREV and HEV hybrid electric vehicle (Hybrid Electric Vehicle, HEV) is that the power output part of HEV is directly connected to t...

AI Technical Summary

Problems solved by technology

[0005] Technical route 2 is to use PI controller to control the power of the system, and use voltage and current sensors to calculate the power feedback value. Since the current loop using PI control contains current coupling items, compensation items need to be added to ensure the dynamic performance of the current loop, resulting in The system control structure is complex and lacks robustness. Some literatures also give robust control methods, such as fuzzy logic control, and the control method using DP technology to obtain the optimal solution

However, these control strategies, such as the DP algorithm, are not suitable for real-time control, because this control method is based on the calculation of multiple driving cycles, thus requiring a large amount of data processing

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