Why does power factor matter Make-up of distribution capacitor banks Discussion Topics Why does power factor matter Make-up of distribution capacitor banks Benefits of power factor correction Switching considerations Conventional switching Synchronous switching

Why does Power Factor matter?

Why does Power Factor matter? We can visualize power delivery as being analogous to a glass of beer from a bar tap. Think of the beer as being real power, while the foam on top is reactive power. We only really care about the beer, but the less careful the person pouring is, the more of the glass will be filled with foam. Since the glass can only hold so much of anything, more foam means less beer. A small amount is OK, but too much foam means you’re not getting beer you paid for! Power distribution systems work the same way. The grid can only provide a certain amount of power, so when someone consumes lots of reactive power, it reduces the amount of real power available to sell to other customers. kVAr kW

Scope: Some causes of poor power factor

Scope: Components of a Distribution Pole bank For Power Factor Correction applications Pole banks (or pad-mounted banks) Frames free standing and self supporting 5kV thru 35kV Capacitor kVAr ratings from 150 to 3600 Shunt connected Fixed (no switches) or Switched Arresters Switches, junction boxes + wiring, frames Single phase or three phase measurement Control power transformer Controllers

Question: Name 3 major benefits of capacitor banks: Power Factor correction I2R loss reduction Voltage improvement

Power Factor Correction Decreases system reactive demand Shave peak demand to decrease energy costs

Placement example: Distribution feeder 300kW load at end of feeder 500 kVA

Power factor correction not applied Placement example: Distribution feeder Power factor correction not applied 500 kVA 300 kW 0.6 pf 400 kVAr Metered Demand 500 kVA

Power factor correction not applied 500 kVA 300 kW 0.6 pf 400 kVAr Metered Demand Placement example: Power factor correction not applied 500 kVA 500 kVA 300 kW 0.6 pf 400 kVAr Feeder Demand

300kVAr switched bank applied Placement example: 300kVAr switched bank applied 500 kVA 300 kW 0.6 pf 400 kVAr Metered Demand 300kVAr switched Cap Bank 500 kVA 500 kVA 300 kW 0.6 pf 400 kVAr Feeder Demand

300kVAr switched bank applied Placement example: 300kVAr switched bank applied 500 kVA 300 kW 0.6 pf 400 kVAr Metered Demand 300kVAr switched Cap Bank 500 kVA Feeder Demand 316 kVA 100 kVAr 0.95 pf 300 kW

Correction example: 450kVAr not applied 500 kVA Metered Demand 300 kW 0.6 pf 400 kVAr Metered Demand Correction example: 450kVAr not applied 450kVAr switched Cap Bank 500 kVA Feeder Demand 500 kVA 300 kW 0.6 pf 400 kVAr

Unity pf (slightly exceeded) Correction example: 450kVAr bank applied Unity pf (slightly exceeded) 500 kVA 300 kW 0.6 pf 400 kVAr Metered Demand 450kVAr switched Cap Bank 500 kVA 304 kVA 300 kW -0.99 pf 50 kVAr Feeder Demand

Boost Voltage Achieve voltage improvement by distributed placement of reactive compensation to: Reduce feeder reactive impedance Reduce feeder load, I2R drop, and voltage sags

Typical Voltage Sag

Voltage sag with 1 capacitor bank closed

Voltage sag with 2 capacitor banks closed

Voltage sag with 3 capacitor banks closed

Question: Name 3 major benefits of capacitor banks: Trinetics Capacitor Switches Question: Name 3 major benefits of capacitor banks: Power Factor correction I2R loss reduction Voltage improvement

Question: Name 3 major benefits of capacitor banks: Trinetics Capacitor Switches Question: Name 3 major benefits of capacitor banks: Power Factor correction I2R loss reduction Voltage improvement Conservation voltage reduction

Conservation voltage reduction Switch reactive compensation upon demand to: Inject voltage during system controlled kVA reduction programs. Reduce supply side metered demand peaks while maintaining service capacity and continuity. Dispatch capacity gains to serve new markets

Normal voltage level

Normal voltage level Reduced voltage level