Control method for improving warming-up speed of engine of hybrid power system

Abstract

The invention provides a control method for improving the warming-up speed of an engine of a hybrid power system. The advantages of a hybrid power system framework are fully utilized, the effects of a generator and a power battery are exerted, the engine warming-up speed during low-temperature cold start of the engine is improved, the response speed of a special vehicle is increased, and the waiting time of the vehicle under the low-temperature start condition is shortened. According to the method, for a hybrid power system architecture vehicle of a generator controlled in a voltage mode, an engine controlled in a rotating speed mode and a power battery in a floating charging form, the target rotating speed of the engine and the target generating voltage of the generator are adjusted in real time to change the generating power (namely, the load power of the engine) of the generator, and the warming-up efficiency of the engine can be improved. Compared with a traditional idling warming-up mode, the temperature increasing speed of the engine is higher, and the warming-up waiting time of the vehicle is shortened.

Description

technical field [0001] The invention relates to a control method, in particular to a control method for increasing the engine warm-up speed of a hybrid system, and belongs to the technical field of comprehensive control of a power system of a hybrid vehicle. Background technique [0002] At present, when a high-power diesel engine hybrid special vehicle is started from a cold engine, the low temperature of the engine leads to poor power characteristics and slow response speed of the engine, while the power output response of the generator under the same temperature condition is very fast; When you start driving the vehicle, it will be difficult to increase the engine speed, and the engine speed will be lowered or even stalled if you step on the accelerator a little faster. The performance of the above phenomenon at the vehicle level is: if the car is driven at a low-temperature cold start without sufficient warm-up, there will be problems of insufficient power, black smoke, ...

AI Technical Summary

Problems solved by technology

[0004] However, in some hybrid power system architectures of "'voltage mode' controlled generator + 'speed mode' controlled engine + 'float charge' power battery", due to the voltage fluctuation of the power battery when the low-temperature cold engine starts As a result, the appropriate power generation target voltage cannot be determined, the engine and generator do not have a power control mode, which makes it impossible to adjust the power of the generator to match the power of the engine in real time, and the charging and discharging of the power battery is uncontrollable. "running" warm-up method, the waiting time for warm-up is longer

[0005] Another commonly used method is as figure 1 The "fixed target power generation voltage" shown - the target power generation voltage = the static voltage of the power battery before the engine starts + the voltage increase value. This "voltage increase value" needs to be obtained through multiple tests, and the "voltage increase value" that is too large It will cause problems such as excessive load, engine speed throbbing, and battery charging current being too large when switching from "engine no-load idling operation" to "power generation mode with load operation"

At the same time, this method also has a limitation: as the "true voltage" of the power battery gets closer and closer to the target power generation voltage of the generator, the power of the generator will become smaller and smaller, which will affect the "on-load warm-up" of the engine. weak effect

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