Capacitor as Voltage Regulator

[sesa190510_brid]

Dear Expert,

LE GUILLOU THIERRY, Ravindra N KULKARNI Yeong Jia CHENG

I have discussion with friend about that it is possible to use Capacitor bank to regulate voltage.

What I understand, the capacitor will be used as "generator of reactive power" and reduce the current demand. Then, it will reduce voltage drop.

However, I still wondering about the controller. If it used as voltage regulator, then the controlled parameter must be voltage, doesn't it? CMIIW

Could we use Varlogic or another typical VAR regulator for this purpose?

Or what should we do?

I also notice, if the system inductance is becoming lower, then it is possible the capacitor will be "Over compensation" and lead to overvoltage. Is there some limitation of allowed maximum voltage to reach?

Thank you for your attention.

BR

Yorga

[sesa47073_bridg · Accepted solution]

Hi Yorga ROHIMMUDIN EFFENDI, please see the summary of using PFC according to IEEE STD 1036.

The capacitor by itself can be used for many purposes. However, the main purpose of Varlogic is to control the turning on/off of cap bank to ensure the targeted PF is achieved. And you are right, voltage regulator requires the input reference to be voltage and hence I believe Varlogic is not designed for that voltage regulation purpose.

If you required voltage regulation, you have to use the equipment which is designed to regulate the voltage. For example the SureVolt from UST Power.

Of course, when you over compensate the system (leading PF = more capacitive), then the voltage will increased according to the equation given by IEEE STD 1036. See slide 25 in the "Energy Savings & PQ.ppt" which I've uploaded.

I hope this helps.

[sesa190510_brid]

Hi John,

Thank you for your information.

BR,