Control method of operating point of hybrid electric vehicle engine

Abstract

The invention discloses a control method of an operating point of a hybrid electric vehicle engine. In the control process of the engine operating points, a hybrid control unit (HCU) adjusts and selects the best operating points of the engine in auxiliary drive state and in generating state respectively according to the state of charge (SOC) of power battery, and determines the necessity for actually adjusting the operating points of the engine by comparing ISG motor combined efficiency with the ratio relation between fuel consumption difference and energy consumption difference before and after the adjustment of the engine operating points. The technical proposal of the invention can bring the following advantages: (1) reducing engine displacement, thus effectively reducing emission and fuel consumption; (2) carrying out generation and auxiliary drive of the ISG motor according to the state of power battery, thus adjusting the engine operating points, improving work efficiency of theengine, and improving power performance; (3) synthesizing each system efficiency of the system, carrying out arbitration on overall efficiency of the system, and excluding the operating points withoutneed for adjustment.

Description

technical field [0001] The invention relates to the field of engine operating point control for hybrid electric vehicles, in particular to a method for improving the working efficiency of the engine and taking into account the working efficiency of the entire system when the charging and discharging depth of the power battery of the hybrid electric vehicle is small. A method for engine operating point control. Background technique [0002] With the increasing consumption of global oil resources causing the shortage of energy supply and the gradual deterioration of the global environment, from the perspective of alleviating resource tension and protecting the environment, as well as meeting the regulatory requirements of various governments and the promotion of government incentives, hybrid power As a new energy vehicle, automobiles have become popular all over the world. The powertrain system of a hybrid electric vehicle is a combination of the engine and the motor. One of ...

AI Technical Summary

Problems solved by technology

However, in the previous hybrid system design, it was often not taken into account to adjust the operating point of the engine according to the state of charge of the power battery, nor did it take into account the effect of the change in the efficiency of each component during the energy conversion process on the efficiency of the entire system. The impact of the motor, and the extremely low efficiency of the motor when it is working with a small torque, resulting in a large blindness in the adjustment of the generator operating point, which reduces the working efficiency of the entire system and increases fuel consumption.

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