The no-load loss is a very important value, representing a considerable amount of energy during the lifetime of the transformer. The no-load losses are caused by the no-load current which is necessary to excite the transformer core. Measuring the no-load loss and no-load current for a transformer is an important aspect of ensuring its efficiency and performance.
The no-load loss of a transformer refers to the power loss in the transformer when it is not connected to any load. This loss is due to core losses, which include hysteresis and eddy currents. The no-load current, on the other hand, is the current flowing through the transformer when it is not loaded. This current is also known as the magnetizing current, which is required to magnetize the core of the transformer.
Because there are decreased voltages required, the no-load size is carried out on the low-voltage facet of the transformer underneath the test. Built-in cutting-edge transformers need to be shorted all through the check and condenser bushing faucets need to be earthed. Before carrying out the no-load loss test, the voltage ratio has to be checked. For oil transformers, the bushings and Buchholz relay have to be vented and the oil stage of the transformer needs to be checked. Before the proper loss measurements take vicinity the transformer needs to be excited by way of 1,1 to 1,15 instances of rated voltage. The over-excitation reduces the consequences of remanence brought about by way of direct cutting-edge excitation throughout the resistance dimension or from the Switching impulse test. Until the measured figures are now not steady, the genuine loss dimension can't start.