Research Of Electronic Control System On Electric Excavator

Excavator is one of the main building machinery of engineering construction.How to improve it, effectively save energy and protect the environment has been an issue that countries and enterprises fully focus on. Traditional excavator is powered by the diesel engine; it leads to large energy consumption and environmental pollution. Therefore, to develop a kind of energy conservation, environmental protection, safe and reliable electric excavator that used motor as power supply, can effectively solve the problem. Electronic control system is the core component of electric excavator, the research of that is of great significance for environmental protection and energy saving, also to improve the automation level of electric excavator.In this thesis the architecture and working principle of the electric excavator are analyzed. A design scheme that using motor instead of diesel engine based on frequency conversion and speed control is presented. For electric control system,direct torque control scheme is chosen, mathematical model of asynchronous motor and frequency converter is established, using the Simulink of simulation software Matlab to build and analyze the simulation model. In simulation analyses torque response within a certain range is fluctuating, it need to be adjusted with the research of control strategy. So in view of the existing problems, the control strategy of fuzzy PID is proposed. The system design is optimized by the fuzzy PI speed controller used in control strategy, the simulation results show that stator flux linkage waveform of direct torque control system is stable, torque response is rapid and torque ripple is reduced, speed control is accurate, it can meet the design requirements.The design of hardware and software of electronic control system of electric excavator are finished in this thesis. The PLC and frequency converter interface circuit, speed measurement circuit, power supply circuit, phase sequence protection circuit, hydraulic oil temperature measurement circuit, anti-jamming circuit, touchscreen interface circuit and its interface display design are mainly accomplished in hardware design. Software design included the design of PLC program,anti-jamming program design.Related test system is developed, tested and debugged in laboratory, the results show that this electronic control system speed control precisely, operate simply,drive safely, it achieves the desired effects.