Research On The Reliability Of Elevator Inverter Drive System

Elevators and escalators are widely used in residential,commercial real estate and other fields.However,different kinds of elevator malfunctions and accidents have occurred recently including doors failing to open,car falling abnormally,elevator emergency stop,etc.,which have overshadowed the elevator system safety indeed.Elevators relate closely to people's livelihood and to public security.Therefore,an increasing and huge importance has been attached to elevators system safety by the government,industry committee,related companies and enterprises,etc.In addition,inverter drive is a core component of elevator system and plays a very crucial role in elevator operation stability.Based on the abovementioned background,reliability analysis and research of elevator-used drive system have been addressed and implemented in this thesis according to the application in the fields of domestic military products,aerospace and electric vehicles,etc.The main research object in this thesis is elevator-used inverter drive system which is divided into five sub-systems including the main control board?driver board,energy storage units,speed and position signal acquisition circuit,input/output interface circuit,etc.Reliability analysis of inverter drive system has been implemented according to the following four steps.Firstly,Understand the basic theory of reliability of the key components used in the frequency conversion system and the reliability parameters of the electronic components and the reliability standard of electronic components.Secondly,according to the specific parameters of the drive system of the elevator special drive system,calculate the relevant parameters of the drive system,build the drive system platform design and each subsystem circuit platform.Thirdly,the introduction of reliability concept in the design of driving system,the standard expected reliability of electronic equipment from the aerospace and military goods,reference military standard GJB/Z 299B-2006 and the military standard MIL-HDBK reliability prediction of MCU control chip,MOSFET,transistors,resistors,capacitors and other electronic components failure modeling reference standard 217 two a reliability,according to the actual conditions in the elevator drive system in the field of environmental stress,selection of components Quality Coefficient,Component Structure Coefficient and circuit working stress related parameters to estimate the product failure rate.To calculate the series components reliably predicted model,the failure rate of components can be accumulated in the subsystems and the total system failure rate,but also by the product of the MTBF(Mean Time Between Failures).Fourthly,with the help of reliability analysis methods widely recognized at home and abroad of FMEA to determine the driving system of the potential failure modes and failure consequence,put forward related preventive measures to reduce or solve the potential failure probability measures,improve the reliability of drive system products.The results show that the reliability of work is a tedious and persistent work,not a short duration of time to complete.It requires designers and maintainers to maintain and update.Reliability Prediction and DFMEA can be in the stage of product design for the quality of the role of escort.