-
Anonymous users2024-02-06Hello! Short lead protection is mainly for the 500kV voltage level.
3/2 of the wiring mode. When a line is out of service, the corresponding primary protection is also taken out of service. If the main transformer is still running at this time, there is no protection for quick action if the short lead on the circuit breaker side fails, so the short lead differential protection is added.
There is no selectivity for short-lead differential protection, so the line (or unit) disconnector is generally used.
The auxiliary contact to control the investment and withdrawal protection. That is: the line stops, the short lead is cast, and vice versa.
Supplement: the main wiring adopts a series of switches in the wiring mode of 3 2 switches, when a line in a series of switches is deactivated, the isolation switch on the side of the line will be disconnected, and the voltage transformer for protection is also deactivated, and the main protection of the line is deactivated, so there will be no rapid protection to cut off the fault in the short lead range. For this purpose, it is necessary to set up short lead protection, that is, short lead longitudinal differential protection.
In the case of the above-mentioned faults, the protection can quickly remove the fault.
When the line is running and the line-side isolation switch is put into operation, the short-lead protection ** roadside fault will act inselectively, so the short-lead protection must be deactivated. Generally, it can be controlled by the auxiliary contact of the line-side disconnector, and the short lead protection is deactivated when closing.
-
Anonymous users2024-02-05The short lead is the part between the side switch and the middle switch in the 3 2 wiring mode.
When the line is running, the protection range of the short lead ** road protection, and when the ** road exits the operation (the line knife is opened), the line protection then exits the operation, at this time, the short lead loses protection, therefore, a special short lead protection is set up to protect the short lead in this case.
-
Anonymous users2024-02-04The so-called short lead protection is in the 3 2 circuit breaker (or angle) wiring, when the components (lines or transformers) connected between the two circuit breakers are withdrawn or overhauled, and in order to ensure the reliability of power supply, the string is restored to the ring network operation in a specific way, and the protection device is installed to protect the connection between the two circuit breakers and the short lead to the capacitive voltage transformer. It is essentially a type of current differential protection. Short lead faults should be acted upon when both circuit breakers trip and their reclosers are locked.
-
Anonymous users2024-02-03It is a type of relay protection. It refers to the wiring of 3 2 circuit breakers or bridge wiring or expansion unit wiring, when the line or transformer connected between the two circuit breakers is deactivated, due to the main protection of the line or transformer exits, a small section of the connection between the two circuit breakers becomes a protection dead zone.
Basic principle. The protective relay must have the function to correctly distinguish whether the protected element is in normal operation or has failed, and whether it is a fault in the protected area or outside the zone. In order to realize this function, the protection device needs to be composed based on the characteristics of the change of electrical and physical quantities before and after the failure of the power system.
By taking advantage of the change in the amount of electrical power in the event of a short-circuit fault, it is possible to construct relay protection based on various principles.
In addition, in addition to the above-mentioned protection of the reaction power frequency electrical quantity, there is also the protection of the reaction non-power frequency electrical quantity, such as gas protection.
-
Anonymous users2024-02-02In general, double busbars do not need to be equipped with short lead protection. The short lead is only used when wiring 3 2. Since I haven't touched the booster station, or you send a ** I'll take a look at your main wiring.
When the equipment is put into operation for the first time, it is generally to exit the tripping outlet pressure plate of the bus differential protection, so as you said, to prevent the secondary current from being connected wrongly, causing the difference current to be too large, and jumping off the original line in normal operation. The pressure plate you return should be the pressure plate for bus protection, right?
There is no set standard for this, as long as you like it. It's either personality or tradition. >>>More
What is the three long and two short seasons? The answer is the Tiger, the Tiger is the third in the zodiac, people born in the Year of the Tiger have strong independence and self-esteem, like to act alone, are too gregarious, like others to obey him, be a big brother, and are the protectors of ordinary people. >>>More
Sleeping in an unfamiliar place for the first time, many people are not used to it. >>>More
Answer: Why did primitive man have a short lifespan.
The reasons are as follows: 1. The level of medical care is low, and there are many diseases without modern medicines** Countless people die of illness, and the mortality rate of children at birth is high; >>>More
The key is awareness and thinking, and Japanese players know how to use their strengths. To put it bluntly, the Japanese have the same way of thinking when playing football as European players, and the technical polishing is easy to achieve as long as there is a good training environment when you are a child. Besides, now little Japan's body doesn't want to be short anymore, and it's also very good.