THE ABCs OFPOWER CONDITIONING

A Simplified Approach to Understanding Power Quality

Problems and How to Solve Them.

What is the origin of power quality problems?

Usually they have an earthly source

Hildegard, switch off the mixer, my monitor is

flickering!

And I don‘t mean this one . . . .

Where Do Power Quality Problems Start?

• Disturbances are generated external to a facility.

• Disturbances are generated internal to a facility.

The Four D’s of Power Disturbances

• Destruction– High energy

– Short duration

– Visible evidence

– Easy to establish cause and effect

The Four D’s of Power Disturbances

• Degradation– Low energy

– Constant exposure

– Cumulative damage

– No visible evidence

– Electronic rust

The Four D’s of Power Disturbances

• Disruption– Low energy– Interferes with

operation of logic circuits

– Lockups, reboots, program dumps

– No trouble found system failures

– Frustration

The Four D’s of Power Disturbances

• Dynamics– Noise that can be heard

– Noise that can be seen

– Noise that interferes with the enjoyment of the production, performance, or meeting

How Do Power DisturbancesEnter an Electronic System?

There are two pathways

Normal ModePhase (hot) to Neutral

Should be <10 volts

Common ModeNeutral to Ground

Should be < ½ volt

The Nature of Power Problems

• 10% of problems are outages

• 90% are noise, voltage surges, harmonics, etc.

• It’s what you don’t see that can kill you

10%

90%

What Devices Are Used To Solve Power Problems. Which Device Is The Appropriate One

To Use?

SIMPLE AS A-B-C

The Voltage Surge

A – The Surge Diverter

Clamping Level

Power Line Noise

AC – The Surge Diverter & Filter

Common Mode Voltage

• Voltage measured neutral to ground– Voltage spikes– Conducted noise– Radiated noise– Unbalanced electrical distribution– Circuit loading

GEAR

B – Isolation Transformer

Balanced Power Transformer

H

G

N

60 volts

60 volts

Voltage Sags and Swells

• Short term (less than 1 minute) decrease or increase in line voltage

• Variety of causes both internal and external

• Most modern loads are relatively immune

D – The Voltage Regulator

• Variety of technologies– Ferroresonant (undesirable for modern gear)– Tap switching autoformer (better)– Tap switching isolation transformer (better yet)– Electronic regulator with isolated output (best

bet)

Power Outages

• Complete loss of power for seconds to hours in duration

• Usually the result of a power company failure although may have internal facility causes, too.

E – The Uninterruptible Power Supply (UPS)

• Converts chemical energy stored in batteries to electrical energy to power the load

• A variety of technologies (standby, line interactive, on line

• Some are power conditioned some are not

• BUYER BEWARE!

Not All UPSs Are Alike

If You Need a UPS

• It should be sine wave inverter design

• Inverter topology depends on the gear and application (standby or on line)

• Must have an isolation transformer if you want it to also provide power conditioning

An Integrated Approach

• Using an integrated ABCs approach will– Prevent destruction, degradation, and disruption

and safeguard dynamics– Protect from the full range of power quality

problems that affect your systems– Improve system performance– Reduce operating and repair costs– Increase satisfaction

Questions ?