Hybrid power system for hydraulic system and engineering machine

Abstract

The invention provides a hybrid power system for a hydraulic system. The hybrid power system comprises an engine, a gearbox, a coupling device, an alternating-current generator, a frequency converter, an alternating-current frequency conversion motor and a hydraulic pump, wherein the engine outputs a rotating speed and torque and is used for driving the alternating-current generator; the gearbox is connected to the engine, adjusts the rotating speed and torque of the engine and transmits the adjusted rotating speed and torque to the alternating-current generator through the coupling device, so that the alternating-current generator works at a rated rotating speed; the alternating-current generator is connected to the frequency converter, generates electric energy and transmits the electric energy to the frequency converter; the frequency converter controls voltage and current which are output to the alternating-current frequency conversion motor according to the adjusted output frequency; the alternating-current frequency conversion motor is connected to the hydraulic pump, and the rotating speed and torque of the alternating-current frequency conversion motor are adjusted according to the input voltage and current; and the hydraulic pump adjusts the output flow of hydraulic oil according to the rotating speed and torque of the alternating-current frequency conversion motor. The hybrid power system is more convenient to control by a mode that the hydraulic pump is only driven by the alternating-current frequency conversion motor, and the safety and energy-saving efficiency of the system are improved. The invention also provides an engineering machine.

Description

technical field [0001] The present invention relates to the technical field of power systems, in particular, to a hybrid power system for a hydraulic system and an engineering machine with the hybrid power system for a hydraulic system. Background technique [0002] At present, the small-tonnage full-hydraulic cranes (below 100 tons) are mainly connected to the hydraulic pump by the walking engine of the getting off the car through the gearbox to provide the power source for the hydraulic system on the car; while the large-tonnage full-hydraulic crane is equipped with a separate engine on the car, The engine is directly connected to the hydraulic pump to provide a power source for the hydraulic system on the vehicle. [0003] The frequency conversion type full-hydraulic crane hybrid power device disclosed in the related art, such as figure 1 As shown, it includes engine 1, engine coupling 2, hydraulic pump 3, hydraulic pipeline 4, hydraulic system 5, frequency adjustment pe...

AI Technical Summary

Problems solved by technology

[0005] 1) When there is no ground power supply, only the engine power source can be used, and frequency conversion speed regulation and energy saving cannot be realized;

[0006] 2) The parallel design of two hydraulic pumps makes the control of the hydraulic system pipeline and oil circuit more complicated, and also increases the production cost;

[0007] 3) The design of the electrical part is too simple, and there are potential electrical safety hazards;

[0008] 4) The control method is single, and there are too many processes that rely on human operation, so there are hidden dangers of human operation

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