real =VIcosO
reactive
= VI sino
A voltamp is a unit of apparent power, which is the combination of voltage and current in an electrical circuit. A watt, on the other hand, is a unit of real power, which is the actual power consumed by a device. The relationship between voltamps and watts is that in an ideal circuit with no reactive components, the apparent power (voltamps) is equal to the real power (watts). However, in real-world circuits with reactive components like inductors and capacitors, the apparent power can be greater than the real power due to the presence of reactive power.
Complex power is a measure of power in an alternating current (AC) circuit that combines both real power and reactive power. It is represented as a complex number, typically denoted by ( S = P + jQ ), where ( P ) is the real power (measured in watts) that performs useful work, and ( Q ) is the reactive power (measured in volt-amperes reactive, or VAR) that oscillates between the source and the load but does no net work. The magnitude of complex power indicates the total power in the system, while the angle provides information about the phase difference between voltage and current.
In a wattmeter used for measuring reactive power, the magnetic circuit (mc) terminal is not short-circuited to ensure that it can accurately measure the voltage across the load. Short-circuiting the mc terminal would eliminate the voltage component necessary for calculating reactive power, as reactive power is determined by the product of voltage and current at a phase difference of 90 degrees. This allows the wattmeter to differentiate between real and reactive power, providing a correct measurement of the reactive power in the system.
The main difference between VA and watts in measuring electrical power is that VA (volt-amps) represents the apparent power in an electrical circuit, which includes both real power (watts) and reactive power. Watts, on the other hand, only measure the real power consumed by a device. In simple terms, VA accounts for the total power used by a device, while watts measure the actual usable power.
Watts measure real power in an electrical circuit, while volt-amps measure apparent power, which includes both real and reactive power. Watts represent actual energy consumed or produced, while volt-amps account for the total power flowing in a circuit.
Use a wattmeter, as it only reads 'real power' of your load. Use an ammeter and a voltmeter, and the product of the two readings will give you 'apparent power' of your load. Since apparent power is the vector sum of real power and reactive power, use the following equation to find the reactive power of your load: (reactive power)2 = (apparent power)2 - (real power)2
According to Wikipedia, all forms of power can be expressed in Watts, but typically one expresses only REAL Power in Watts (& Kilowatts).The standard is to express Apparent Power in Volt-Amperes (VA) (& KVA).The kilowatt is the unit of measure for true power; apparent power is measured in volt amperes.However, the volt ampere and the reactive volt ampere (for reactive power) are traditional units, used to help differentiate between apparent, true, and reactive power. SI recognises the watt as the unit for each.
Watts measure real power, while VA (volt-amperes) measure apparent power. Real power is the actual power consumed by a device, while apparent power includes both real power and reactive power. In simple terms, watts represent the actual work being done, while VA accounts for the total power used by a device.
Watts measure real power, while VA (volt-amperes) measure apparent power. Real power is the actual power consumed by a device, while apparent power includes both real power and reactive power. In simple terms, watts represent the actual work being done, while VA accounts for the total power used by a device.
'Active power' (also known as 'true power' and 'real power') is the rate of energy dissipation by the in-phase component of current in an AC circuit, expressed in watts.Active power is the vector-difference between apparent power (measured in volt amperes) and reactive power (measured in reactive volt amperes).Expressed in terms of apparent power: Active Power = Apparent Power x power factor = U I cos (phi)
The firing delay angle is the point in the AC cycle at which a thyristor starts conducting. By adjusting this angle, the power factor of the system can be controlled as it affects the balance between real power and reactive power. A smaller firing delay angle can improve the power factor by reducing the phase difference between voltage and current.
A VAr meter only measures the reactive (imaginary) power. Apparent power is a combination of real and reactive power; thus having a VAr meter will not suffice to measure apparent power. Likewise, because the VAr meter only measures reactive power, it does not provide any information on real power.