SELECTING POWER TRANSFORMERS WITH DIFFERENT SHORT CIRCUIT VOLTAGES FOR PARALLEL OPERATION
Parallel operation of transformers (TR) is one of the key solutions for improving the reliability of power supply, production, traction power substations, port production capacities. TR operation influences the cost effectiveness of different cycles of equipment operation and no-load losses when the equipment is not operated. Creating the most economical cycle of operation of the entire port infrastructure is considered, which will ensure not only the equipment operation, but also maintainability with trouble-free power supply cycle. TR operation requires the precise calculation and necessary conditions for switching, which allows to conduct prompt repair of equipment, proper control of the operation of each TR and each node separately. A complete shutdown of equipment with its further conservation during the period when the equipment is not needed is found possible. There were carried out calculations for the TR parallel operation, which prove the economic benefits of TR parallel operation. Some formulas are derived from the theoretical foundations of electrical engineering. Many calculations present the empirical studies in the field of transformer engineering and power networks. Practical solutions are summarized in tables, where TR options with different passport data are presented. There has been found which of the TRs on the market meet the condition of parallel connection. There are considered the TRs most convenient for gaining the required power. The research results can facilitate the choice of TR when designing new power supply sections and upgrading existing ones. It has been stated that the TR models designed for operation in difficult geoclimatic conditions, on the offshore platforms, in zones of extreme cold and high temperatures are not presented. TR of this design require a separate study due to the specific working conditions.