On Load Tap Changer Oil Immersed Power Transformer Technical Application
Regarding the oil-immersed transformer with on-load voltage regulation, in order to improve the quality of power supply, the load-regulated voltage is used to reduce the line loss. Because of the load adjustment of the oil-immersed transformer, the non-working balance state of the system cannot be changed. To avoid voltage collapse, the system should have sufficient dead capacity. In the design and non-efficiency planning of the grid, it is necessary to comprehensively consider increasing the voltage intensity of the grid. The system realizes the layered and partitioned balance of inactive power, optimizes sufficient emergency reserve capacity, collapses the voltage through switching operations, and avoids large-scale power outages. When the system is in great chaos and the voltage drops sharply, the regulator should take timely measures to cut off the load adjustment and part of the load, eliminate the shortage of active power and inactive power in the system, or set up an automatic load shedding device to control the system. Oil immersed transformer controls, high speed operation and restriction bureaus offset these negative effects. Partial mobilization develops into a network-wide or major network accident.
According to the Technical Guidelines for Power Systems, in addition to 220 kV, there are also access voltages for installing switching oil-immersed transformers and switching oil-immersed transformers (for example, bus junctions on the sending and receiving sides of power stations with large output variations). continue. Among them, the grid voltage may change greatly. Usually, it is not suitable to adjust the load voltage. Load voltage adjustment. Regarding high voltage and large capacity, it is equipped with branch switch submerged transformers (including step-up load switch submerged transformers and wiring load switch submerged transformers) to improve reliability and prevent resonant over-voltage as far as possible without grounding, only when necessary can be adjusted in air voltage mode. The oil pressure immersed transformer for full range voltage adjustment is protected by a zinc oxide surge arrester for absorbing voltage.
When two load switches operate in parallel, the rated load current of the oil-immersed transformer of 85% of the switches is lower than the allowable switch. The rated load current of the oil-immersed transformer for 85% of the switches is higher than the allowable switch. At the same time, in order to ensure the synchronous switching of the two oil-immersed transformers during load adjustment, reliable asynchronous protection is required. Strictly implement the Power System Voltage Failure Management Regulations. In the oil-immersed type, there is voltage regulation transformer management within the voltage management range. The power dispatching departments at all levels can automatically compensate the cutout when the voltage level of the positive terminal changes according to the changes of load and flow, so as to realize the comprehensive optimal management of system voltage and reactive power.
