A transformer is an electrical machine whose device is designed to convert one alternating current value into another. Transformers operate on alternating current. These machines have received the widest distribution, since electricity must be transmitted over long distances at voltages that are much higher than the level that is necessary to power industry or for use at home. Thus, the use of a transformer makes it possible to reduce the losses of electricity during its transmission and increase the quality of the process. One of the most important characteristics of this machine is the efficiency of the transformer, that is, the efficiency. Another important characteristic is the transformation ratio, which is determined by the ratio of the input voltage to the output voltage.
A transformer is usually a static device. A conventional transformer (and there are several types) consists of a core, which is assembled from ferromagnetic plates, as well as secondary and primary windings, which are located opposite to the core. As already mentioned, there are main types of transformers: step-up (the output voltage is greater than the input) andstep-down (voltage at the output is less than at the input). One of the important conditions for the operation of the device is one voltage frequency.
To determine the efficiency of a transformer, we introduce the following notation:
- P1 - electrical power consumed by the transformer,
- P2 - output power,
- PL is the power loss.
In this case, the energy conservation law will take the form: P1=P2+ PL. Using these notations, it is easy to derive the formula for the efficiency of a transformer. The efficiency formula will look like this: n=P2/ P1=(P1- PL)/ P1=1- PL/ P1. As you can see, it can be presented in several versions. From the last formula it can be seen that the efficiency of the transformer cannot be more than 1 (that is, it is impossible to obtain an efficiency greater than one hundred percent). This is understandable.
Correctly calculating the efficiency of a transformer is a more complex issue than it might seem at first glance. When designing and developing circuits and the overall design of a transformer or a series of transformers of a certain type, design engineers often encounter certain problems. For example, to reduce the cost of a transformer, it is necessary to minimize the consumption of materials. However, on the other hand, in order to make the device more reliable in operation, the consumption of these materials will have to be increased.
It is for these conflicting reasons that the efficiency of a transformer is usually made standard, thereby normalizing losses. When determining the value of the coefficientThe efficiency of the transformer must take into account the cost of materials, the cost of electricity and transmission lines, that is, take into account many economic factors. The efficiency of a transformer may vary with load, and this factor must also be taken into account when designing this unit.
