Research On Electronic Ballast For Electrodeless Lamp And Its Intelligent Control System

Electrodeless lamp is highly appreciated for it’s major advantages,such as long life,high light efficiency,saving energy and protecting environment.Therefore,it has been already widely used in various lighting situation,such as tunnels,factory floors,mines.The performance of electronic ballast is the key to ensuring stable work of electrodeless lamp.As Intelligent lighting is able to meet the diverse requirements of lighting.Therefore,the research on the electronic ballast and its intelligent control system has the great significance and application prospects.This paper firstly introduces the development and research status of electronic ballast for electrodeless lamp,then analysis operating principle,load matching and circuit characteristics of electronic ballast which based on LCCL resonant network.According to the different working status of the electrodeless lamp with the starting process to steady state,a digital control of electronic ballast which suits for the load characteristic of the electrodeless lamp is designed.Through the automatic sweeping frequency which can generate a high frequency and high voltage pulse required by the starting process when the working frequency is equal to natural resonant frequency of the circuit.So,it realized the safety and reliability of the lamp start.Due to the change of load and the resonant parameters which causes the problem of the resonant frequency-shift and power output variation,a closed loop frequency tracking control scheme based on the phase difference as the control variable is designed,which can effectively track the resonant frequency of the resonant network and guarantee the circuit to work in the best condition.A bi-frequency constant power close-loop and indirect control scheme with resonant converter input current as control variable,which solves the problem of power output variation and realizes constant output power of the system.The paper presents a combination of the bi-frequency modulation and the improved pulse density modulation composite dimming scheme which realizes the full range and the high precision dimming of electrodeless lamp.According to the requirement of intelligent lighting control,we put the Zigbee technology into the electronic ballast of the electrodeless lamp and then design a intelligent control system.Giving the specific implementation method of the intelligent lighting control system,including hardware circuit and software design process.Finally,a 100W the electronic ballast of the electrodeless lamp experimental prototype using dsPIC microcontroller as the main controller and Zigbee dimming is developed.The experimental data and waveform analysis verify the correctness of the theoretical study.