kilovoltból

The kilovoltampere (symbolized as kVA) is a unit of apparent power in the International System of Units (SI), commonly used in electrical engineering to quantify the capacity of electrical equipment such as transformers, generators, and circuit breakers. Apparent power represents the vector sum of real power (measured in kilowatts, kW) and reactive power (measured in kilovolt-amperes reactive, kVAR), combining both resistive and inductive or capacitive loads in an alternating current (AC) system. Unlike real power, which performs actual work, apparent power accounts for the total energy flow in an electrical circuit, including energy that oscillates between the source and load without performing useful work.

The kilovoltampere is derived from the voltampere (VA), where one kilovoltampere equals 1,000 voltamperes. It is calculated by multiplying the root mean square (RMS) voltage (in kilovolts, kV) by the RMS current (in amperes, A). For example, a transformer rated at 100 kVA with a voltage rating of 10 kV would carry a maximum current of approximately 10 amperes (100 kVA ÷ 10 kV = 10 A). This rating ensures the equipment can handle the specified load without overheating or failure.

In power systems, kVA ratings help engineers determine the suitability of equipment for a given application, considering both the real and reactive components of the load. Unlike kilowatts, which measure only the useful power consumed, kVA accounts for the entire power flow, making it essential for designing efficient electrical systems. The distinction between kVA and kW is particularly important in applications involving inductive loads, such as motors and transformers, where reactive power significantly impacts system performance.