# Calculate Capacitors Power

In general, to calculate the necessary Power of Capacitors, we can use the following formula:

Qc = P ( tgφ1 – tgφ2 )

where :

- Qc : the Power of Capacitors.

- P : the total Power of Loads that are running during normal working.

- tgφ1 : the tangent of φ1 ( the angel between current & voltage before compensation )

- tgφ2 : the tangent of φ2 ( the angel between current & voltage after compensation )

In all cases, we should take into consideration the following points :

1- It will be better to oversize the calculated Qc by " 10 to 15% ".

2- Be careful when compensate the PF of a Motor to avoid the Over-excitation case, but we can verify it by using the following formula : Qc (motor) = 2 x P (1 - Cos φ ), where :

- P : the Motor's Power.

- Cos φ : the PF of the motor before compensation.

3- After calculation of Qc, the choosing of Capacitors type will be done according to the Harmonic Distortion percentage. Noting that in some case where the Harmonic Distortion percentage is high, we should use " Detuned Reactors " with Capacitors, and when this percentage is too high, we can't install the Capacitors before minimizing or eliminating the harmonics that their percentages are too high.

Qc = P ( tgφ1 – tgφ2 )

where :

- Qc : the Power of Capacitors.

- P : the total Power of Loads that are running during normal working.

- tgφ1 : the tangent of φ1 ( the angel between current & voltage before compensation )

- tgφ2 : the tangent of φ2 ( the angel between current & voltage after compensation )

In all cases, we should take into consideration the following points :

1- It will be better to oversize the calculated Qc by " 10 to 15% ".

2- Be careful when compensate the PF of a Motor to avoid the Over-excitation case, but we can verify it by using the following formula : Qc (motor) = 2 x P (1 - Cos φ ), where :

- P : the Motor's Power.

- Cos φ : the PF of the motor before compensation.

3- After calculation of Qc, the choosing of Capacitors type will be done according to the Harmonic Distortion percentage. Noting that in some case where the Harmonic Distortion percentage is high, we should use " Detuned Reactors " with Capacitors, and when this percentage is too high, we can't install the Capacitors before minimizing or eliminating the harmonics that their percentages are too high.

If you look back over history you will find how things started out from the early engineers and scientists looking at materials and developing systems that would meet their transmission goals. I recall when ...

Before breaker's selecting for your electrical system, you need to calculate value of expected short circuit current at the place of breaker's installation. Then you need to calculate value of heat pulse and ...

I work across the scale of power electronics in voltages and currents. From switchers of 1W for powering ICs to 3kW telco power supplies up to multi-megawatt power converters for reactive power control in AC ...

Variable frequency drive includes main circuit, power circuit, IPM drive and protection circuits, cooling fan and other several parts. The structure is mostly unitized or modular. Incorrect or unreasonable ...

There are hundreds of applications for a frequency inverter. I use them on a pump to test pumps with voltages from 208-600VAC 3PH 50 and 60 HZ. You just have to size the frequency inverter to the largest 208 ...

Gozuk Blog: all about electric motor control & drives industries development in energy saving applications.

Like pumps, fans consume significant electrical energy while serving several applications. In many plants, the VFDs (variable ...
A frequency inverter controls AC motor speed. The frequency inverter converts the fixed supply frequency (60 Hz) to a ...
Motor starter (also known as soft starter, motor soft starter) is a electronic device integrates soft start, soft stop, ...
Soft starter allows the output voltage decreases gradually to achieve soft stop, in order to protect the equipment. Such as the ...
Soft Starter reduces electric motor starting current to 2-4 times during motor start up, reduces the impact to power grid during ...

why the ct has turns ratio 1 or 5 in the secondary side irrespective of the primary side?

High saturation flux ferrite for PFC Choke

HiPot v/s Megger Test

How to check transformer Oil IR value

DC Power Supply 5VDC @ 1A from solar panel array

In what way is OPC better for PLC-SCADA comms?

how we can differentiate faults and disturbances in a power system??

Selection of motor rpm and gear ratio

High saturation flux ferrite for PFC Choke

HiPot v/s Megger Test

How to check transformer Oil IR value

DC Power Supply 5VDC @ 1A from solar panel array

In what way is OPC better for PLC-SCADA comms?

how we can differentiate faults and disturbances in a power system??

Selection of motor rpm and gear ratio