Power down flow processing method and system of Plug-in automobile

Abstract

The invention provides a power down flow processing method of a Plug-in automobile. The power down flow processing method comprises reducing a torque value of an engine to a firth preset scope when receiving key OFF gear signals, then reducing a rotate speed value of a generator to a second preset scope, sending stop instructions to a battery control unit, enabling the battery control unit to control a battery to stop power supply, sending instructions for closing an insulated gate bipolar translator (IGBT) to the generator, and discharging electric energy in the generator. The IGBT in the generator is closed after the torque value of the generator is reduced to the firth preset scope and the rotate speed value of the generator is reduced to the second preset scope, a load torque of the engine is small, a power generation assembly produces small electric energy, a direct current side of the generator cannot produce high transient voltage in the moment when the IGBT is closed, performance of the IGBT is not influenced, and service life of the generator is prolonged.

Description

technical field [0001] The present application belongs to the field of new energy vehicles, and in particular relates to a method and system for processing a power-off process of a Plug-in vehicle. Background technique [0002] A Plug-in vehicle is composed of a traditional internal combustion engine and an electric drive system. It can obtain electric energy from the power supply network through a charging device, and can drive the vehicle only through the electric drive system within a certain driving distance under the premise of ensuring the vehicle's dynamic performance. Reducing human dependence on petroleum resources can effectively reduce greenhouse gas emissions. [0003] The plug-in car replaces the flywheel of the engine with a generator, and the power generation assembly is composed of a generator and an engine. When the power generation assembly needs to start, the generator drives the engine to complete the starting process; when the power generation assembly ...

AI Technical Summary

Problems solved by technology

When the power generation assembly is working, the generator receives the HCU stop command. Since the load torque of the engine connected to the generator has not been completely unloaded, the power generation assembly will still generate electric energy during the decline of the generator speed. The change curve of the DC terminal voltage of the machine is as follows: figure 1 As shown, it can be seen that at the moment when the generator IGBT is turned off, a high peak voltage appears on the DC terminal of the generator. Once the peak voltage exceeds the maximum voltage that the IGBT can withstand, it will cause damage to the generator and reduce its service life.

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