Piezoelectric Ceramic Type Injector Drive System

With the aggravation of the energy crisis and the increasingly stringent emission regulations,the traditional solenoid valve injectors are increasingly difficult to meet people's energy saving and environmental protection requirements.However,the piezoelectric ceramic injector with its fast response,small size,high sensitivity and high accuracy and resolution of displacement,fuel injector has become the mainstream direction of development.Therefore,the research on the driving system of piezoelectric ceramic injector has very important significance.In this paper,the characteristics of piezoelectric ceramics are introduced firstly,and then the working principle of piezoelectric ceramic stacks on the injector drive system is analyzed in detail.Then according to the characteristics of piezoelectric ceramic stacks,Current drive mode,the preferred choice of current drive mode.Aiming at the current driving mode,we choose the single-peak current driving mode and multi-peak current driving mode,which are common at present,to analyze and research.Finally,in theory,the piezoelectric ceramic actuator control system for high accuracy,fast response requirements,made in-depth theoretical analysis and design of a piezoelectric ceramic injector drive system.The system consists of a microcontroller MCU,DC / DC boost circuit,charge-discharge circuit,voltage feedback circuit,current feedback circuit.Its working principle is: Before injecting the fuel injector,the boost circuit of the MCU controls the voltage of the vehicle storage battery to12 V to 100 V so as to drive the piezoelectric ceramic stack to be deformed.The pulse width modulation(PWM)signal generated by the MCU Acting on the charge-discharge circuit,charge,discharge control,through the current,voltage feedback circuit circuit real-time information fed back to the MCU.Then the MCU uses the Fuzzy-PID algorithm to process the feedback result,and the processed result is applied to the charging and discharging circuit,so that the driving current and voltage of the driving circuit are kept within the set range,thereby improving the dynamic stability of the system,Fuel injection system current and voltage control more accurate,to achieve multiple injection.The experimental results show that the charge-discharge time of piezoelectric ceramic actuator is between 100?s and 200?s,and the voltage can be rapidly changed in about 150?s,which meets the control requirements of the driver and verifies the correctness and superiority of the system.