Are there 110KV and 220KV voltage levels inside a power plant?

There are 110KV and 220KV voltage levels in power plants.

Power plant voltage level, there are 220V, 400V, 6KV, 11KV, 220KV.

Power plant voltage level division:

Electrical main wiring mainly refers to the power plant, substation, power system, in order to meet the predetermined power transmission and operation and other requirements designed to show that the high-voltage electrical equipment interconnected with each other in relation to the transmission of electric energy Circuit. High-voltage electrical equipment in the circuit includes generators, transformers, busbars, circuit breakers, disconnectors, lines and so on. The way they are connected plays a decisive role in power supply reliability, operational flexibility and economic rationality. Generally, when studying the main wiring scheme and operation mode, the three-phase circuit diagram is usually depicted as a single-line diagram for clarity and convenience. In the drawing of the main wiring diagram, the transformer, arrester, capacitor, neutral point equipment and carrier communication with the channel processing components (also known as high-frequency oscilloscope) and so on are also expressed.

For a power plant, the electrical main wiring in the plant design according to the unit capacity, plant size and power plant in the power system status, from the reliability of power supply, flexibility and ease of operation, economy, development and expansion possibilities, etc., determined after a comprehensive comparison. It is wired to reflect the supply and delivery of power under normal and accidental conditions. Electrical main wiring is also known as electrical primary wiring diagram.

500KV: the so-called unit wiring is the generator and the main transformer is directly connected to a unit, forming a generator-transformer group. It has the advantages of simple wiring, less switchgear, easy to operate. The generator - double winding transformer unit wiring, is a large unit commonly used wiring. Generator and transformer capacity matching. Such as 1000MW (1120MVA) unit is equipped with 3 × 380MVA main transformer to meet the generator with full load and deduct the plant power load part, the transformer capacity to match. The traditional generator-transformer group connection, in the generator outlet without circuit breakers, generator outlet through the split-phase fully enclosed bus and double-winding transformer directly connected to the low-voltage side, and then by the main transformer step-up to 500KV with the grid connection. At present, the advantages of installing a switch for the outlet of large units are more and more recognized, although the one-time investment is larger, but simplifies the plant power switching operation procedures, improves the protection level of generator and main transformer, high-voltage transformer, simplifies the same period of operation, facilitates the maintenance, debugging, shortens the fault recovery time, and improves the availability of the unit. It makes the power system stability as well as the flexibility of operation significantly improved, therefore, in the way of generator-transformer unit wiring, the use of generator outlet circuit breaker installation has become the trend. After installing circuit breakers at the generator outlet, the generator can realize the parallelism and de-parallelism with the system by operating the outlet circuit breaker, and after the shutdown, the plant system can send power backward through the main transformer, which eliminates the inverted gate operation of the plant system due to the shutdown. The power supply during normal start-up of the generator set can be back-fed from 500KV through the main transformer to the high-voltage plant transformer. When the generator fails, the faulty unit can also be quickly removed through the exit circuit breaker, ensuring the stability of the power system.

10KV and 6KV plant power system:

The voltage of the high-voltage plant power system adopts two levels of 6KV and 10KV, and the neutral point of the low-voltage side of the two high-voltage plant transformers of 6KV is grounded by a 6.1Ω resistance, and the neutral point of the low-voltage side of the 10KV is grounded by a 10.2Ω resistance, and the high-voltage plant busbar is a single-busbar wiring. Plant power system in accordance with the principle of generator export switch design, plant power source from the generator to the main transformer on the closed bus between the lead. Such as Taizhou power plant electrical main wiring diagram shown. When the generator is running, with the unit plant power; generator shutdown, just disconnect the generator exit switch, the plant load can still be from the system through the main transformer, and then through the high plant power supply.

The main feature of this wiring method is that the power supply is connected to the four high-voltage factory buses through two high-factory transformers, which not only carries the factory loads of the unit (machine, furnace and electricity), but also carries the public loads. The shutdown/overhaul transformer usually does not carry load.