Structure Design And Analysis Of A New Type HVDC Relay

With the implementation of the national new energy strategy,especially the promotion of new energy vehicles and their high-power quick charging piles,as well as the vigorous development of aviation and other industries,the demand of HVDC relay will increase rapidly,and its performance parameters and safety requirements will become higher and higher.Meanwhile,cost control is also an important factor.This paper will focus on some problems of the traditional DC relay,a new type of motor type HVDC relay which using micro-motor as driving power is designed and analyzed at the first time,namely the structure of the new type DC relay feasibility and the main transmission mechanism and arc performance of touch head off open-close and its related arcing measures has carried on the simulation and experimental analysis,specific work is as follows:1.The types and characteristics of existing relays are described.The types and characteristics of existing traditional relays are comprehensively analyzed.In other words,with the large-scale demand for high-power relay in the new energy vehicle market,the electromagnetic drive mode of traditional relay will have certain development limitations--with the increase of power,the consumables of its excitation coil and permanent magnet system are greatly increased,and their weight,cost and manufacturing difficulty are correspondingly increased.2.Preliminarily completed the structural scheme design of the new type of HVDC relay with motor.Micro motor driven by magnetic coil is used as the driving force to realize the closing and breaking process of electrode contact through gear transmission.The opening and closing distance of the contact can reach several times of the traditional structure.According to the extinguishing principle of DC arc,the arc extinguishing methods,such as large distance separation of contact points,transverse magnetic blowing and a new type of sheet turning partition,are selected.The overall design of the structure scheme is also very compact,which can save a lot of copper wire materials and lower the processing cost,and can be applied to a wide range of voltage and current.Theoretically analyzed the relationship between the contact breaking speed of the new type dc relay and the design parameters of the transmission mechanism,and the design parameters of the transmission mechanism corresponding to the relay breaking speed of 100mm/s are calculated.3.ANSYS Workbench was used to analyze the structural statics of the designed gear transmission mechanism.The stress and deformation distribution cloud diagram of the gear drive mechanism under the design condition is obtained.The dangerous parts of gear failure are analyzed.The maximum stress of the gear group is compared with the yield limit of the material.The results show that the gear transmission mechanism can meet the design requirements of strength and deformation.4.Select the DC voltage parameter of 400V/100A to conduct the simulation analysis of the micro-motor DC relay by using COMSOL finite element software.Based on MHD theory,the arc simulation model is established.The characteristics of arc motion in the process of contact breaking are analyzed and the influence of electrode contact spacing on the current density between contacts is obtained.The breaking arc motion of contacts under different external magnetic field intensities and breaking speeds is modeled.The influence of different applied transverse magnetic field intensity and breaking speed on the airflow between contacts of a new type of DC relay is analyzed.The arc temperature field distribution,current density distribution and arc voltage are analyzed.By analyzing and comparing the characteristics of arc under different conditions,the law between the intensity of the applied magnetic field,the breaking speed of the contact and the arc combustion is summarized.The results show that there are critical saturation values of the influence of the transverse magnetic blowing intensity and the breaking speed of the contact on the arc.5.Designed a new type of dc relay electrical life test scheme.Electrical life test of new type dc relay was carried out.Its electrical life reaches the electrical life standard certified by the relay.It is verified that the structure of the new dc relay transmission mechanism is reasonable and safe and the performance of the arc extinguishing device is good.The design and preliminary analysis of the new HVDC relay in this paper will provide a theoretical basis for the follow-up research,optimization and application of the micro-motor HVDC relay,and provide a new development option for the product development of the HVDC relay in the field of new energy.