Research And Development Of LED Drive Power Performance Test System

The driving power is an important part of the LED lighting system.Its performance directly affects the lighting quality and life of the lighting system.Therefore,it is of great significance to test and evaluate the performance of the LED driving power.At present,the special testing equipment for LED driving power is expensive and bulky,which is not convenient for testing in outdoor occasions.Therefore,it is particularly important to develop a low-cost and portable LED driving power performance test system.This thesis combines virtual instrument and data acquisition technology to design a performance test system for LED driving power.The system can implement functions such as data acquisition,waveform display,parameter calculation,and level evaluation.It is universal and extensible.The main research contents of the paper are as follows:(1)The design requirements of the LED driving power performance test system are studied.The main parameters of performance test include voltage,current,total harmonic distortion rate,ripple crest factor,efficiency,power factor,etc.Reasonable and feasible implementation schemes are also proposed,including hardware and software.(2)Based on the requirements of the test system,a performance test system for LED driving power is designed.Firstly,the appropriate data acquisition card and converter are selected.Then,the filter parameters and the signal conditioning circuit are designed.Through signal conditioning,the voltage(current)is converted into a voltage signal within the input range of the acquisition card.Finally,the ripple detection circuit is designed according to the principle of the ripple signal.The ripple and DC components of the output signal are sent to the data acquisition card respectively to test performance parameters such as the ripple factor of the driving power supply.(3)An electronic load that can be used for LED driving power test is designed.Fuzzy-PID control algorithm is applied to electronic load.The real-time detection circuit voltage(current)is taken as the controller input.Then,the control signal is adjusted in time by querying the control decision table to improve the stability and accuracy of the electronic load software control unit.The control voltage of the circuit is calculated by the current-voltage fitting function of the LED,so that the electronic load can simulate the nonlinear relationship between the current and voltage of the LED.(4)The software program and test front panel of the LED driving power performance test system are designed.According to the principle of modular programming,the programs of the user login module and the performance test module are designed separately.The performance test module includes data acquisition,waveform display,basic parameter test and analysis,harmonic current test and analysis,and ripple test and analysis programs.The system can implement functions such as user management,dynamic acquisition,over-limit signal alarm,and level evaluation.At the end of the thesis,the test platform is built to verify the function of each test module.Then the paper evaluates the feasibility of the system by analyzing the stability and bias of the test data.The research shows that the system can complete the test of key performance parameters of LED driving power.