A control method and device for switching between series and parallel modes of a dual-motor power system

Abstract

The invention relates to a control method and device for switching between series and parallel modes of a dual-motor power system. The method includes: when receiving a request for switching from a series mode to a parallel mode for a dual-motor power system, performing oil filling of the clutch and adjusting the rotational speed of the engine All reach preset conditions, wherein, the dual motors include a first motor and a second motor; when performing oil filling of the clutch and adjusting engine speed both reach preset conditions, it is judged whether the current working state of the clutch satisfies the locked state ; If the current working state meets the locked state, the clutch starts to lock and simultaneously performs torque compensation to the first motor or the second motor until the clutch is locked. After the clutch is locked, the first motor and the second motor Torque exchange between them, the drive system is switched from series mode to parallel mode; the present invention adopts the torque compensation of dual motors, which can offset the inertial torque difference caused by the inconsistency of the angular acceleration at both ends of the clutch, reduce the impact of clutch lock-up, and make the series The smooth transition of parallel mode switching improves drivability.

Description

technical field [0001] The invention relates to the field of hybrid power technology, in particular to a control method and device for switching between series and parallel modes of a dual-motor power system. Background technique [0002] With the development of the economy and the reduction of traditional energy sources, more and more car manufacturers are developing hybrid vehicles to replace traditional energy vehicles, which can solve the traditional energy reduction and meet the daily travel needs of people. [0003] At present, the mainstream products of hybrid systems on the market are single-motor hybrid architectures. However, when the engine intervenes at low and medium speeds in a single-motor hybrid system, the efficiency of the vehicle will be reduced because the engine cannot work in the high-efficiency range. Many Automakers have developed a dual-motor hybrid system, which can solve the problem that the engine cannot work in the high-efficiency range at low an...

AI Technical Summary

Problems solved by technology

[0003] At present, the mainstream products of hybrid systems on the market are single-motor hybrid architectures. However, when the engine intervenes at low and medium speeds in a single-motor hybrid system, the efficiency of the vehicle will be reduced because the engine cannot work in the high-efficiency range. Many Automakers have developed a hybrid system with a dual-motor architecture, which can solve the problem that the engine cannot work in the high-efficiency range at low and medium speeds, and improve vehicle efficiency

[0004] However, in an architecture similar to the dual-motor architecture, the switch between the serial mode (Serial Mode) and the parallel mode (Parallel Mode) is switched by controlling the opening and closing of a clutch. In the serial mode, the low-speed battery SOC is insufficient or When the output power of the battery does not meet the demand, the engine starts, and the engine speed is adjusted to an optimal working condition to use the P1 motor to generate power. The power generation is mainly used to drive the P2 motor. In the working condition, the engine speed can be adjusted freely because the clutch is open; in parallel mode, when the vehicle is running at high speed, the engine power is directly output through the gearbox through the clutch engagement, and the engine speed is very high at this time, which can easily reach the optimum Efficiency working range; when switching from the series mode to the parallel mode, the clutch needs to be combined. Generally, the speed difference between the two ends of the clutch reaches a certain value through speed regulation (motor speed regulation or clutch friction speed regulation) and then the clutch is locked. Realize switching between series and parallel connection, however, in the prior art, at the end of the speed regulation, if there is a difference in the angular acceleration of the shafts at both ends of the clutch, the lock-up clutch will generate inertial impact, which will affect the drivability

[0005] Therefore, in the prior art, due to the difference in the angular acceleration of the shafts at both ends of the clutch, the inertial impact of the clutch is an urgent problem for those skilled in the art.

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