Many people, when they talk about such a thing as electric power, mean a certain force. However, even in the school physics course, knowledge was given that power and strength are different concepts, albeit interconnected.
The very concept of “power” means a characteristic of a particular event. In this case, you can associate power with some object. Any physical effect can be called the action of force. Perfect work is the path traveled with the help of applied force. Work done by force in a certain time will be equal to power. Thus, power is a physical quantity equal to the ratio of work done in a given 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 called the change in energy in a certain system (energy conversion rate).
Although the above terms and definitions relate more to mechanical energy, from this all we can deduce such a thing as "electric power". The product of current and voltage is called the current power. Since this concept depends equally on 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, motion, light). Electrical power is measured in watts (W). In everyday life, such energy is usually measured in kilowatts, and in large power plants, larger units, megawatts, are also used.
Reactive electrical power characterizes the electrical load in various devices. It is equal to the product of the voltage drop by the operating current and the sine of the phase angle (phase shift) between the current and the voltage drop. Measured reactive power in reactive volt-amperes (VAR).
Active power can be associated with electrical power through such a thing as “cosine phi” - the difference between the phases of the current and voltage. For most household appliances, this cosine will be approximately 0.8. For heating appliances, it is often raised practically to unity.
Electric power is measured by a special device - a wattmeter. Such a device has two windings. The first is a thick wire, connected together with consumers of electricity and records the change in the magnitude of the current. The second winding consists of a thinner wire and is connected in parallel to take into account the voltage in the network. Power plants often use the concept of “installed electrical power”, which is the sum of all the rated capacities of all electrical machines of only one type or type (for example, transformers, generators, motors).