Power Factor Correction KW KVA KVAR

Reasons behind P.F corrections n Power Factor is the ratio between Power and Apparent Power n Motors

Formula P.F P.F = watts/va Or P.F = P/S

Power Factor Improvement n Over Correction n Individual power factor correction

Power Factor Improvement n Group power factor correction

Utility P.F Correction n centralized automatic power factor correction

Common Types of Capacitors

3 Phase Capacitor

Reactors n Shunt Reactors n Series Reactors

Underground Networks n Edmonton downtown network n Calgary downtown network

Benefits of Power Factor Correction n Reduce electrical costs. n Reduce load losses of the distribution system. I²R Loss n Increase the system's capacity. n Maintain a better voltage regulation on the system. n Improves P.F.

Safety n Capacitors hold charges n High Quality Capacitors n Capacitors in transit

Rules for P.F Calculations n Power input in a load is what the utility see as load n P= KW or W

Rules n Power is constant u KW or Watts n Output power is what the customer sees u KW or Watts

Rules n Cal. All Power original P.F 1 st SmPmQmSmPmQmSmPmQmSmPmQm n Cal. All Power New P.F (corrected p.f) u Using Pm – constant u S cor and Q cor or Delivered

Rules n Find the Qreq or the Q of the cap required to correct the P.F u Q cap = Q m - Q cor n Cal Size of Cap’s Xc value u Xc = E²/Qcap

Rules n Cal the Cap size to μF u C=1 x 10 6 / 2п f Xc n Assume 60 Hz

Rules n Size the cap for total bank size if required per individual cap divide by 3 n Remember Power is always constant Qt = √S² - P²