Simulation Research On Emergency Power Supply With Double Transform Function

With the rapid development of science and technology in today’s world,almost all life and work are inseparable from the supply of electric energy,especially in various large-scale industrial fields,medical and health fields,and national defense and military fields.Once the power supply of the power grid fails,it is likely to cause Serious safety accidents or huge economic losses.Therefore,when the power grid fails,it is an important goal to be able to provide sufficient power and ensure high-quality power quality.Therefore,a variety of emergency power supply（EPS）devices are constantly being developed and researched.A complete set of emergency power supply consists of several basic components,including battery pack,rectifier charger,inverter,AC and DC filters,etc.The more traditional emergency power supply technology is mainly based on battery charging technology,DC/AC inverter technology,and emergency power supply system composed of bypass switching.However,the traditional design has many shortcomings,such as the switching after the grid failure is not fast enough,the output voltage is not stable enough,and the power quality is poor.In this paper,the emergency power supply with double conversion function is designed using SPWM pulse width modulation technology,that is,on the basis of PWM pulse width modulation technology,a sine wave is used to modulate a square wave that changes according to the sine law,and the research on emergency power supply is carried out.The double conversion function is added on the basis of the emergency power supply.The core of the emergency power supply system with double conversion function is two aspects.On the one hand,when the grid is normal,the grid directly supplies power to the load.When the battery pack is under-powered and needs to be charged,the AC power input from the grid is stepped down by the PWM converter and the bidirectional DC/DC converter to charge the battery pack.At this time,the PWM converter is in a rectifying state.When the power grid fails,the battery pack needs to start to discharge,and the output DC power is converted into AC power after the bidirectional DC/DC converter boosts and PWM converter,and supplies power to the load in an emergency.At this time,the PWM converter is in reverse change state.Finally,after a sufficient theoretical analysis,MATLAB/Simulink is used to simulate and design each part of the emergency power supply circuit,and the circuit combination is completed to realize the function of the emergency power supply,and the waveforms of the power grid in normal and abnormal states are analyzed respectively.