High Reliable Motor Control System Based On New Type Of Failover Switches

Under the guidance of the supervisor,the author of the paper invented a motor control system based on a new type of failover switch which can improve the system reliability by the redundancy technique.The construction and operating principle of the new redundant system are introduced in the paper: If some branches in a system need high reliability,n-1 standby branches are added to the system.For example,the branch including controller and motor driver needs high reliability,n-1 standby branches are added to the control system.Among the n-1 standby branches and working branch,every branch have a failover switch in which a STM32 single chip microcomputer works as key part.During system operation,one branch keeps work and other branches wait as cold standby,and the STM32 in the n switches keep communication each other.Once the operating branch is out of order,its microcomputer will certainly send appointed signals to the microcomputers in all of the standby branches,and the n-1 switches of the standby branches will turn on simultaneously,thus all standby branches go to work simultaneously.The microcomputers will immediately judge whether the branches can work normally,and then,the system would select a normal branch to keep on work,while other circuit branches exit as the later backups.If the circuit branch failures again,above method things would be done again.In the paper,the calculation model for the reliability of the new redundant system is established and the practical computational formula was derived.The author designed and made three different prototypes of DC motor closed-loop control systems according to the model of the new redundant system.The overall design,hardware design and software program of the three prototypes were introduced in detail.In the paper,validity test and verification test for the calculation method of reliability for the failover switches are narrated.In order to quicken the test,some artificially failures such as short-circuit,disconnection,overload and locked-rotor are created in the experiments.The result of the experiments show that the three prototypes have got anticipative effect.Through information research,we know that all of available failover switch redundant systems have one failover switch.The reliability of the system is limited by the reliability of the failover switch.In available parallel redundant system,n redundant circuit branches operated simultaneously,so it was obvious that n-1 circuit branches waste electricity and consume life of hardware.In a control system,n parallel controllers sent n control signals to controlled objects,which will be disturbed and some adverse effects will occur.However,our new redundant structure can avoid the problems.In the paper,the superiority of the new redundant system is proved theoretically and practically.It was shown theoretically that our redundant system can achieve any anticipant task reliability.The new type of failover switch redundant system in the paper is the innovative design.The result of research presented in the paper are helpful for the theory and engineering practice of electromechanical system reliability.The result can be used for the aircrafts,space crafts,nuclear power stations,power plants,bullet trains,ships,warships and production facilities,and so on,especially for the machine systems for which the safety accidents may be caused by failure or important task will be influenced.