Research On Transient Disturbance Protection Technology Of Power Electronic System

In recent years,electrification,intelligence,networking,and sharing have gradually gained practical application in the automotive industry.The electromagnetic environment in automotive use is becoming increasingly complex.The requirements for anti-electromagnetic interference ability of on-board electronic equipment are becoming stricter.Transient disturbance protection ability is an important part of automobile anti-electromagnetic interference,which mainly includes transient transmission pulse protection and electrostatic discharge protection of power lines.The major international standards for these two types of interference in the automotive industry are ISO7637-2,ISO16750-2 and ISO10605.In this paper,the protection technology of transient conduction pulse and electrostatic discharge pulse of power line is studied by the methods of theoretical calculation,modeling simulation and physical verification.The paper derives the voltage function of the transient pulse generator by deriving the load voltage function in the relevant standards.The transient frequency distribution of the voltage function of the transient pulse generator shows that the frequency spectrum of the transient conduction pulse is mainly distributed in the low frequency range,and the energy is high,which is the main cause of device damage.Transient conducted pulse interference can be absorbed by selecting appropriate protective devices.However,unlike transient conduction pulses,electrostatic discharge pulses contain not only high-energy and low-frequency interference components,but also abundant lower-energy high-frequency interference components.High-frequency interference mainly affects the normal transmission of signals through parasitic capacitance and inductance between layers on the PCB board and between lines.Therefore,for the protection against electrostatic discharge pulses,in addition to selecting suitable protective devices to absorb high-energy and low-frequency interference components,it is also necessary to eliminate the coupling path through PCB layout optimization to reduce the impact of high-frequency interference.The paper uses the pulse energy equivalent method to accurately calculate the transient pulse energy,which can effectively guide the parameter selection of the protective element.The protection circuit for negative transient transient pulses can be protected by selecting a diode or MOS according to the operating current.Based on the above conclusions,the paper builds a PSPICE model of partial pulse(Pulse1,2a,3a,3b,5b,and electrostatic discharge)generators,and builds an actual circuit for verification.It is proved that the transient pulse constructed in this paper is equivalent to the standard,and the protective measures are feasible.In addition,the paper deduces the calculation method of parasitic capacitance and inductance between PCB layers and wires,and gives effective PCB layout and suggestions.When the working frequency is different,the PCB layout scheme is also different.The paper used COMSOL software to verify the feasibility of the layout scheme.This paper has conducted a complete study on transient pulse interference protection technology.This paper deduces the voltage function of the transient pulse generator and the calculation method of parasitic capacitance and inductance between PCB layers and wires.The pulse energy equivalent method is used to accurately calculate the transient pulse energy.Some transient pulse generation methods in ISO7637-2,ISO16750-2 and ISO10605 standards are given,and protection circuits are designed.Laboratory verification shows that using the method described in the paper,the transient pulses generated by the transient pulse generator are highly equivalent to the standards,and the protection circuit and PCB layout scheme are reliable.