Research On Energy Recovery And Grid Connected Technology Of BLDC Power Generation

In the BLDC lifting system,when in the braking operation,it is in the generation state.The pumping voltage is produced on the DC bus of the BLDC driver.It is harmful to the filter capacitor.A energy recovery grid device is used to suppress the pumping voltage,solving the issue of the traditional energy consumption resistance:(1)the generation energy is consumed on the resistance,resulting in the waste of energy;(2)the heat generated by the resistance increases the temperature of the working environment and affects the normal operation of surrounding other equipments.The energy recovery device of the BLDC in the braking operation is essentially a three phase voltage source PWM rectifier.The main works are as follows:1.The mathematical model of three phase voltage source PWM rectifier is built in three phase stationary coordinate system and two phase synchronous rotating coordinate system.The principle and realization method of space vector pulse width modulation(SVPWM)are introduced.2.The feedforward decoupling method of the mathematical model of three phase voltage source PWM rectifier is completed.The voltage external loop and current inner loop are designed.The simulation model is built in the MATLAB,and the simulation results are analyzed.3.The power and control circuit of energy recovery device of the BLDC in the braking operation is designed.In the power circuit,the power switch tube,inductor and DC side capacitor are selected.In the control circuit,the minimum system,drive circuit,voltage and current sampling circuit and protection circuit are designed.4.The main program and subprogram of energy recovery device of the BLDC in the braking operation are designed.In the subprogram,the AD sampling program,the SVPWM modulation program and the protection program are designed.5.The test waveforms of BLDC power generation grid connected recovery device are analyzed,and the results of theoretical analysis are verified.The results of theoretical analysis,simulation and test prove that saving energy and increasing efficiency,improving work condition,advancing applicability in some special environment are achieved.