Anti misoperation locking method of isolating swit

Anti misoperation locking method of isolating switch in unattended station

electrical misoperation accident poses a great threat to electrical safety, equipment safety and personal safety. In the electrical misoperation, it is more serious to pull and close the switch by mistake with load. The more effective way to solve the misoperation of disconnector is to adopt the method of anti misoperation locking

with the progress of science and technology, substations have developed from manned to unattended, and the anti error locking of disconnectors has also developed from mechanical locking, ordinary electrical locking to microcomputer locking. The following mainly talks about several methods of realizing error proof locking of disconnectors in unattended substations

1 electrical error prevention locking

the electrical error prevention locking method is also a traditional error prevention locking method, which makes the 1 use additive in the eyepiece comply with the gb9685 standard. The horizontal line of the 0-word dash line is tangent to the front and rear edges of the wear spot respectively. This method has been used to operate and lock the disconnector from the conventional manned substation, and this method is still applicable to the unattended station (i.e. integrated automation substation). Electrical lockout is to connect the auxiliary contacts of relevant circuit breakers, disconnectors and grounding disconnectors in series in the electric operation circuit of the disconnector. Only when the positions of relevant circuit breakers, disconnectors and grounding disconnectors are correct, the electrical lockout circuit of the disconnector can be connected, and the disconnector can be operated electrically (that is, local and remote electric operations can be realized)

the reliability of electrical locking in the operation of unattended stations is not high. Because the locking principle is that several auxiliary contacts are connected in series in the electric operation circuit of the disconnector (knife switch), when one of the contacts is not in good contact, the whole circuit fault will be caused, so that normal operation cannot be achieved, especially when the substation is unattended, remote unlocking cannot be achieved. In addition, when other equipment in the electric operation circuit has faults, there is no locking limit when inspectors want to conduct local manual operation, so the electric locking only works during electric operation, and its locking reliability is not high

2 microcomputer anti misoperation lockout

the microcomputer anti misoperation lockout of unattended station is mainly through the communication between the anti misoperation computer and the integrated automation measurement and control device. The anti misoperation computer judges whether the disconnector to be operated meets the action conditions through the current position of the circuit breaker, disconnector and grounding knife switch collected by the measurement and control device. If it meets the action conditions, it sends a permission command to the measurement and control device to operate the disconnector, On the contrary, a locking command is sent. At the same time, the microcomputer anti misoperation locking device is also equipped with corresponding electrical lock (for local electric operation of the disconnector) and mechanical lock (for local manual operation of the disconnector)

microcomputer anti misoperation locking technology has been developed for more than ten years, and it also has a great breakthrough in anti misoperation. It not only solves the problem of unreliable contact of electrical locking (the normal operation of measurement and control device will not be affected when the anti misoperation microcomputer fails), but also solves the disadvantage that electrical locking cannot lock manual operation. The anti error locking mode of microcomputer is gradually accepted by most professionals

3 combination of electrical locking and microcomputer error prevention locking

although microcomputer error prevention locking solves the two shortcomings of electrical locking, its error prevention effect is also good, but once microcomputer error prevention fails, the isolating switch that completely relies on microcomputer error prevention will have no error prevention locking function, which is the disadvantage that PolyOne, a major player in microcomputer error prevention, will be on Chinaplas, the largest plastic products exhibition in Asia. The way to solve this problem is to combine the electrical locking with the microcomputer error prevention to prevent the error locking of the disconnector

this kind of locking method still works even in case of misoperation prevention microcomputer failure, and the reliability of misoperation prevention is quite high. However, the disadvantage of this method is the same as that of electrical locking, that is, when the contact of electrical locking circuit is poor and causes a fault, remote unlocking cannot be achieved

4 improvement of the combination of electrical locking and microcomputer error prevention locking

in order to solve the problem of poor contact and failure of normal operation in the combination of electrical locking and microcomputer error prevention locking, the control switch KK and remote control contact JS can be incorporated into the electrical locking circuit. The control switch KK is installed in the operating mechanism box or circuit breaker terminal box of the corresponding disconnector (depending on the actual situation of each station, the position should be the same as the local opening and closing buttons of the disconnector). Its function is to urgently unlock the electrical locking circuit when the local electric operation 2. Force measurement accuracy: 1n operation cannot be carried out normally. The remote control contact is introduced by the integrated automatic measurement and control device, which can be used for emergency unlocking of the electrical locking circuit when the remote operation cannot be carried out normally. After local or remote unlocking (i.e. closing the control switch KK or closing the remote control contact JS), the error prevention task of the disconnector is undertaken by the microcomputer error prevention device, and its reliability can still be guaranteed. If the disconnector cannot be operated after the electrical lockout is released, then the electrical lockout must be restored (i.e. opening KK or waiting for JS contact to return), and carefully check whether the operation steps are correct and whether the disconnector has been misoperated. It is not easy to unlock the microcomputer error prevention and forcibly operate the isolating switch

this locking method has high reliability, and also solves the shortcomings of electrical locking and microcomputer error prevention. This locking method has recommended value

locking is one of the most effective methods to prevent misoperation accidents, but the locking method is very complex, so it is difficult to achieve reliable locking and convenient operation. The anti misoperation locking design of unattended substation needs to be further improved in theory and practice, so that misoperation accidents can be reduced or even eliminated, and at the same time, it makes the operation convenient for operators