Transformer selection for industrial building

Choose high efficiency and energy saving transformer

Distribution transformer is the main power supply equipment commonly used in distribution system. It is also a device that consumes a certain amount of power. It runs on the grid for a long time after it is turned on. In general, it is only taken off the grid during maintenance. The accumulated power consumption of improper selection is large, so it is necessary to choose an energy-saving transformer with no load and low load loss. For example, compared to the s9, the S7 series has a higher iron loss rate of 1% and copper loss rate of 28%. The new amorphous alloy transformer is more energy efficient than the S9. The no-load loss of 10kv amorphous alloy transformer is 80% lower than that of s9. The service life of transformers is generally several decades. Replacing energy-intensive transformers with high-efficiency and energy-saving transformers can not only improve energy conversion efficiency, but also save a lot of electricity during the service life. At the same time, it can also bring good environmental benefits, reduce the greenhouse gas emissions of power plants to the atmosphere, reduce the direct pollution to the environment.

Reasonable calculation

The rated capacity of the transformer should meet the needs of all power loads, but cannot be overloaded for a long time. The repeat load of the transformer should be 60% of the rated capacity of the transformer, which is the most effective. Transformer “big horse car” not only makes the capacity of the transformer not fully utilized, but also reduces the operation efficiency of the transformer (increasing the loss rate), which is a waste of transformer operation and investment. Therefore, the capacity of the transformer can not be selected according to the optimal load rate of the transformer, but should be slightly higher than the optimal load rate of the transformer. In general, 75-% is reasonable.

The main distribution facilities of general civil buildings are concentrated in substations, and the power factor of electrical equipment such as lighting and air conditioning is high. Therefore, centralized compensation is mainly used in substations. However, for mechanical factories, some machine tool processing equipment, welding machines, cranes and other power factors are relatively low, and some factories are larger. Due to process requirements, the distribution station cannot penetrate the load center, resulting in a long power supply line for the equipment. According to the current calculation formula,{5 = P; /(broadcast U, because jealous), the lower power factor will directly lead to the current rise, the selection of switches and cables will increase, it is not in line with the principle of energy saving. In this case, it is necessary to disperse local compensation capacitors according to the capacity and nature of the factory equipment, and implement the combination of centralized compensation in the substation and decentralized compensation in the workshop.