Power Factor Correction
The first indication that power factor correction may be needed is a high electricity bill.
Many electricity retailers charge a higher tariff when a customer’s power factor drops to 0.8 or below. Our electrical engineers locate the causes, design the solutions and install the power factor correction equipment, such as capacitor banks, to deliver improvements across all business units – from production to OH&S to finance.
We also measure and verify the changes in power factor to ensure the solution is delivering the planned improvements.
Benefits of power factor correction include:
- Lower electricity bills
- Increased operational capacity – more power available for additional machinery without the need for new switchboards and cable
- Less unscheduled downtime in production or operations
- Increased machinery and equipment life
- Compliance with regulatory codes
- Safer workplace
WHAT IS POWER FACTOR?
Power factor is a measure of how efficiently the load current is being converted into useful work output. A poor power factor occurs when a load is drawing more electrical energy than is necessary for conversion into a given amount of useful work.
Equipment that is likely to impact power factor includes heavy load appliances, such as air conditioners, welding sets, AC motors, arc furnaces, high bay and fluorescent lighting, and transformer-based appliances, such as laptops and computers.
Power factor is calculated using a ratio of real power (kW) to apparent power (kVA), where apparent power is the sum of real power (powering work) and reactive power (not powering work but required by some equipment for it to operate eg creating a magnetic field). This results in a score between 0 and 1.
A system with PF 1 has 100% of the supply being used efficiently; PF 0.5 means half of the power is being wasted or used inefficiently. Once a system produces less than PF 0.9 (90%), it requires correction.
HOW DOES IT WORK?
So consider a barge being pulled by a horse.
Since the horse cannot walk on water its pulling effort is reduced by the “angle” of the tow rope.
If the horse could walk on water then all the horse power is being used to pull the load.
However, the relative position of the horse influences the power. As the horse gets closer to the barge, angle Ø1 increases and power is wasted, but, as the horse is positioned further away, then angle Ø2 gets closer to zero and less power is wasted
By improving Power Factor (reducing the angle), the reactive power component is reduced.