What Is Atresia?

[Word]: lock

[bì su]

[Word]: lock

[Interpretation]: In the natural sciences, it means that a certain system is isolated from the outside world and is not related. Medically, the old fingers and valves are tightly closed: aorta ~ incomplete. ^[1]

[Word]: lock

[Interpretation]: In the natural sciences, it means that a certain system is isolated from the outside world and is not related. Medically, the old fingers and valves are tightly closed: aorta ~ incomplete.

Locking is the connection method between the gun and the barrel during firing. The purpose of the lock is to withstand the pressure on the bottom of the bullet when the bullet is fired. To prevent the premature back seat of the gun. The locking method is divided into inertia lock and rigid lock. Inertia lock is There is no mechanical connection between the gun and the barrel during firing, and it is locked by the inertia of the mass of the gun. There are free guns, semi-free guns, roller delay and other types. Rigid locking is a certain The mechanism is directly connected to the barrel, and then the unlocking mechanism is used to release the gun and release it into the back seat. There are types of gun rotation, barrel swing, clip-iron swing, clip-iron extension, and oblique cymbal.

Simply put, it is the function of the fuse. It was identified as a major equipment accident according to the original "Procedures for the Investigation of Electricity Industry Accidents". After the incident, experts conducted investigation and analysis from various sources and concluded that the equipment's error prevention function was defective and could not play a role in preventing errors. This was one of the main reasons leading to the accident. According to relevant regulations, all high-voltage electrical equipment that may cause misoperation should be equipped with anti-misoperation devices and corresponding anti-misoperation electrical blocking circuits. The anti-misoperation lockout device at the production site mainly implements five prevention functions: preventing the load from closing and closing the isolation switch; preventing the circuit breaker with a ground wire (grounding switch) from being closed; preventing people from entering the charging interval by mistake; preventing the incorrect division and misconnection of the circuit breaker; preventing the electrification Hang the ground wire (close the ground switch); The basic method to achieve the non-synchronous parallel connection is to realize the synchronous blocking by means of pressure difference and frequency difference appraisal devices. During the switching operation, the synchronous blocking device is put in place in time to prevent the non-synchronous closing of the two systems with asynchronous power supply. Implementation methods and characteristics of the five defense functions. For manually operated switchgear, mechanical interlocking is generally achieved mechanically; electrically operated switchgear is connected to the control loop according to a certain logical relationship through auxiliary contacts in the auxiliary switch of the circuit breaker to achieve operation interlocking.

The latching includes: Mechanical latching is a mechanism in which the mechanical structure of the operating mechanism of the switchgear restricts each other to achieve interlocking.

Electromagnetic lock is the use of auxiliary contacts such as circuit breakers, disconnectors, circuit breaker cabinet doors, etc. to turn on or off the power supply of electromagnetic locks such as isolation switches, switch cabinet doors that need to be blocked, so that their operating mechanisms cannot be operated, thereby achieving Interlocking between each other. This locking device is simple in principle and convenient to implement, and can be locked between non-identical switching devices; it operates more reliably in a dry environment. But limited by our "national conditions", most of them are installed on indoor equipment of 35 kV and below. In use, due to various reasons, the auxiliary transfer switch cannot be switched normally, and the electromagnetic lock cannot meet the sealing requirements and is corroded by moisture, which makes the lock often fail. Most of the outdoor high-voltage switchgear to achieve anti-false lockout is electrical logic lockout.

The electrical circuit logic blocking is to use auxiliary contacts of equipment such as circuit breakers and disconnectors to access the electric operation circuits such as isolation switches or grounding knife gates to be blocked, so as to achieve mutual blocking between switching equipment. The characteristic is that the secondary circuit is complicated, the installation and maintenance workload is large, and the comrades who need maintenance often assist or cooperate with the operation in order to eliminate the locking failure in time. The basic condition for its realization is on the device mechanism of electric operation. At present, most outdoor switchgears of 330 kV and below use this type of locking device, but the actual operation situation is far from the ideal target. The main factors are the poor sealing of the auxiliary transfer switch, corrosion and incomplete switching.

Frequent failures of electrical latching, electromagnetic latching, and mechanical latching are often forced to suspend the shutdown operation, and sometimes the chief technical officer has to be instructed to forcibly unlock the operation with the "master key" or remove the latching device. In order to improve the difficult situation of anti-false lockout and the need for safe production, a microcomputer-based anti-false lockout system using functional components such as a host computer, a computer key, an electric code lock, and a mechanical code lock has been applied and promoted. The microcomputer anti-mislocking system is a circuit breaker, an isolating switch, a grounding knife (grounding wire), and auxiliary contacts of a switch cabinet door (or combined with a main wiring simulation drawing board), which is realized by a microcomputer coded lock. The switch device operation program (rules) or the lockout logic is input into the program lock by the software system to perform the reverse operation, that is, adding a microcomputer five-proof contact to the operating power circuit of the electrically operated knife gate or ground knife mechanism box. Microcomputer five defense system is completed independently. However, the five-defense system of the microcomputer is required to have "anti-run (missing items during operation)" measures. At present, a relatively complete microcomputer lock developed by a company in Zhuhai has been widely used in the country. The use of a computer-based anti-false lock system is cumbersome, slow, and the code lock is not easy to install, and individual crashes have restricted its use and promotion.

First of all, it is necessary to ensure that the synchronization circuit wiring is correct, and the synchronization blocking device works well; once the equipment is changed or the synchronization circuit wiring is changed, the phase or nuclear phase must be timely; the operator must be familiar with the synchronization point of the unit and the synchronization circuit at the same time Side-by-side operation prevents two simultaneous power switches from being put into operation; manual synchronization operations must undergo synchronization verification to achieve synchronization lockout; tripping of power connection lines without synchronization verification or higher-level dispatch permission is strictly prohibited.