With the solar panel system and a series of electrical systems into people’s daily life, more and more people began to consider the method of updating these electrical equipment, more and more about improving the efficiency of power supply and the advanced equipment has been put forward, which is about the power transmission efficiency of the circuit, higher power transmission efficiency can not only improve the power supply power of the electrical system, but also can greatly reduce the cost of waste in the process of power supply. Higher power transmission efficiency not only improves the power supply of the electrical system, but also greatly reduces the cost wasted in the power supply process. When it comes to power transmission efficiency, apparent power and effective power will inevitably be mentioned, about the difference between the two and what kind of measurement unit should be used. In this article, we will introduce you to the unit of measurement of apparent power, the kilovolt-ampere (kVA), and how to convert amperes to kilovolts.

1. What is an ampere (A)?

An ampere is a unit of current (I). It is commonly used to describe the amount of current in an electrical circuit. From a microscopic point of view, it indicates how much charge passes through a section of a circuit in an instant, i.e., how fast the current passes through a section.

2. What is the kilovolt-amperes (KVA)? What is the difference between kVA and other power units?

The kilovolt-ampere is a unit of power that is essentially the product of kilovolts and amperes. A similar unit of power is the volt-ampere, and the conversion multiplier between the two is:

1KVA = 1000VA

First of all, we need to know that the difference between the kilovolt-ampere and other units of power is from the difference in the efficiency of power transmission in the circuit, resulting in a difference between the effective power and apparent power, which also results in a difference between the kilovolt-ampere and watts and other units of power.

While both kilovolts and watts are units of measurement for power, kilovolts are commonly used to describe the apparent power (S) in a circuit, which is the product of the AC voltage and AC current in the circuit. The watt, on the other hand, is the unit of measurement for effective power, which is the power actually present in a circuit. When the current and voltage in a circuit are in agreement, the apparent power is equal to the effective power, and as the agreement between the current and voltage decreases, the difference between the two becomes greater and the effective power transferred in the circuit decreases but is generally not zero.

3. How is the conversion from amperes to kilovolts achieved?

After recognizing the physical units of measurement of amperes as well as kilovolt-amperes, we can learn how to convert from amperes to kilovolt-amperes. First of all, since the ampere and the kilovolt-ampere do not belong to the same unit of measurement of physical quantities, in order to realize the conversion between the two, we need to introduce an intermediate unit of measurement of physical quantities: the volt (v). After this, we can begin the conversion from amperes to kilovolt-amperes with the following conversion formula:

S (KVA) = I (A) x {V (v) ÷ 1000}

S in the above formula is the apparent power, I is the circuit current, and V is the circuit voltage. It is worth noting that the formula is divided by 1000, the reason for its existence is because the left side of the equation of the apparent power unit for the kilovolt-ampere, while the right side of the voltage unit is the volt, the two do not belong to the same level of units, in order to make the two balanced, you need to change the right side of the equation of the voltage unit of the volt to the kilovolt, that is, the value of the volt is divided by 1000.

In order for you to learn and master the above equation better, the following will be an example of a household circuit that requires you to try to calculate its apparent power. The circuit has a voltage of 110v and a current of 2A, and its apparent power S = 2A x (110V ÷ 1000) = 0.22KVA.

With this example, I believe you have mastered the above formula. As a matter of fact, for commonly used circuits, they are specifically categorized into two types, the first is DC and the other is AC. The above formula is generally only used when calculating DC, whereas for AC we need to use a more complex conversion formula.

First of all, AC circuits are categorized into single-phase AC and three-phase AC.

Single Phase AC

First, we need to understand what single-phase AC is. Single-phase AC refers to the type of circuit that has only a single AC voltage in the circuit, and the current and voltage generated in the circuit vary with time at a specific frequency.

For a single-phase AC circuit, the formula for converting amperes to kilovolt-amperes is:

S (KVA) = I (A) x {V (v) ÷ 1000}

It is worth noting that the V in the above formula will be changed to the RMS voltage in the AC circuit, i.e. the value of the DC voltage of that circuit versus the DC voltage capable of producing the same heating effect. The reason for this use is that since the voltage in an AC circuit varies with time, the RMS value of the voltage will be taken for the calculation. All other physical quantities are the same as in the DC circuit formula.