Loss, efficiency, and adjustment rate of transformers

Loss is the electrical energy consumed by the transformer itself, and the smaller the range allowed for charging, the better. It includes load losses when used with load and no-load losses when unloaded.

Load loss is the input power when the secondary side is short circuited and a low voltage at the rated frequency is applied to the primary side. When the current is at the rated value, the main loss is copper, which is directly related to the material, cross-sectional area, and winding manufacturing process of the copper wire used.

No load loss refers to the loss caused by opening the primary side and applying the rated voltage at the rated frequency to the secondary side. It mainly consists of iron loss, including hysteresis loss and eddy current loss. The hysteresis loss is directly proportional to the weight of the silicon steel sheet and to the nth power of the magnetic flux density. The eddy current loss is proportional to the square of magnetic flux density, the square of silicon steel thickness, the square of frequency, and the weight of the magnetic material. So it is directly related to the design parameters. Our company uses silicon steel sheets with a thickness of 0.35mm from Nippon Steel H14 in Japan, and greatly reduces iron loss through reasonable design.

Efficiency is the ratio of output power to input power, and the higher the value within the allowable range, the better. The efficiency is highest when the actual load is 60% of the rated value. However, users should choose the optimal load range of 75% -90% of the rated value for cost and practicality considerations. E. The adjustment rate of the transformer. It is the change in the output voltage of the transformer when there is a change in the load current. The reason is the voltage drop caused by the resistance of the winding and the voltage drop caused by the reactance on the leakage flux winding. The smaller the variation of this value within the allowable range, the better. Our company's design value is 1% of the output voltage value.