Power system of range-extended hybrid electric vehicle and control method thereof

Abstract

The invention discloses a power system of a range-extended hybrid electric vehicle. The power system comprises an ISG, an engine, an EMS and an HCU. The ISG works as a starting motor of the engine or works as a generator. The HCU is connected with the EMS through a CAN bus and an independent cable. When the ISG works as the generator, the HCU transmits a target rotation speed signal and a target torque signal of the engine to the EMS through the CAN bus. The HCU further transmits an accelerator position simulation signal to the EMS through the independent cable. The EMS controls the engine to output rotation speed to reach target rotation speed and output torque to reach target torque. It is unnecessary to directly control the ISG by the HCU in the power generation process, so that the control mode of the HCU is simplified, the development difficulty of the range-extended hybrid electric vehicle is lowered, development time is shortened, cost is saved, and reliability is improved.

Description

technical field [0001] The present application relates to a power system of an extended-range hybrid electric vehicle. Background technique [0002] see figure 1 , the power system of a traditional car includes: [0003] ——Engine, usually a gasoline engine, connected to a drive mechanism such as a gearbox; [0004] ——Sensors, including air flow meter (or gas temperature and pressure sensor), engine speed sensor, crankshaft position sensor, etc.; [0005] ——Actuators, including intake valves, fuel injectors, ignition devices, etc.; [0006] ——Engine Management System (EMS for short), which collects the signals of each sensor and controls the operation of each actuator. [0007] The control method of the power system of a traditional car is as follows: various sensors provide the required signals for the EMS, and the EMS calculates the fuel supply amount for each working cycle according to the air-fuel ratio requirements of the engine's operating conditions, and controls v...

AI Technical Summary

Problems solved by technology

However, the rotational speed of the engine will change in a wide range, and the wide-range field weakening control technology of the permanent magnet synchronous motor is very difficult, and the dependence on the parameters of the ISG motor is strong and the dynamic response is poor.

As an alternative, when the ISG works as a generator, a DC-DC converter can also be used to achieve stable voltage generation, but this will increase system costs and reduce power generation efficiency

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