Many people, when they talk about such a thing as electrical power, mean a certain force. However, even in the school physics course, knowledge was given that power and strength are different concepts, although they are interconnected.
The very concept of "power" means the characteristics of a particular event. In this case, you can associate power with some object. Any physical action can be called the action of force. Perfect work is the path traveled with the help of the applied force. The work done by the force in a certain time will be equal to the power. Thus, power is a physical quantity equal to the ratio of the work done in a certain time by a certain force to this period of time.
However, we must not forget that power is also called a measure of energy. Therefore, we can take into account the statement that this term can also be used to refer to the change in energy in a certain system (the rate of energy conversion).
Although the above terms and definitions relate more to mechanical energy, from all this one can deduce such a concept as"electric power". The product of current and voltage is called current power. Since this concept depends equally on both voltage and current, we can say that the same electrical power is obtained both at high current and lower voltage, and at high voltages and low currents. This property underlies the transmission of electrical energy over long distances using power plants, substations, transformers (step-up and step-down), switchgears and other electrical equipment.
Electric power is divided into two main types: reactive and active. Active power is a characteristic of the transformation of electricity into other types of energy (heat, movement, light). Electrical power is measured in watts (W). In everyday life, such energy is usually measured in kilowatts, and large power plants use larger units - megawatts.
Reactive electrical power characterizes the electrical load in various devices. It is equal to the product of the voltage drop and the operating current and the sine of the phase angle (phase shift) between the current and the voltage drop. Reactive power is measured in reactive volt-amperes (VAr).
Active power can be associated with electrical power through such a concept as "cosine phi" - the difference between the phases of current and voltage. For most household appliances, this cosine will be about 0.8. For heating appliances, it is often raised to actuallyunits.
Electrical power is measured with a special device - a wattmeter. Such a device has two windings. The first is a thick wire, connected together with consumers of electricity and captures the change in current. The second winding consists of a thinner wire and is connected in parallel to account for the voltage in the network. Power plants often use the concept of "installed electrical power", which is the sum of all the rated powers of all electrical machines of only one type or type (for example, transformers, generators, motors).
