What is Power Factor?
Power Factor is a measure of how efficiently electrical power is consumed. In the ideal world Power Factor would be unity (or 1). Unfortunately in the real world Power Factor is reduced by highly inductive loads to 0.7 or less. This induction is caused by equipment such as lightly loaded electric motors, luminaire transformers and fluorescent lighting ballasts and welding sets, etc.
What does it do to my electricity bill?
In a 3 phase supply, kW consumed is (VOLTS x AMPS x 1.73 x Power Factor) / 1000. The Electricity Company supply you VOLTS x AMPS and they have to supply extra to make up for the loss caused by poor Power Factor.
PRIME TECHNOLOGIES can carry out Power Quality Analysis at your facility to determine your system loads and power factor at any given time.
When the power factor falls below a set figure, the electricity supply companies charge a premium on the kW being consumed, or, charge for the whole supply as kVA.
What causes Power Factor to change?
Inductive loads cause the AMPS to lag behind the VOLTS. The wave forms of VOLTS and AMPS are then "out of phase" with each other. The more out of phase they become then the lower the Power Factor. Power Factor is usually expressed as Cos Phi. (Ø)
PRIME TECHNOLOGIES offers Capacitors, Surge Capacitors for Overvoltage protection, and Automatic Capacitor banks to reduce your line losses, kVA and electricity bills.
Including, Motor Control devices, Peak load management devices, and overall electricity cost reducing equipment and technologies.
Some Information on Terminologies used in our Power Analysis Reports.
What sort of electrical devices generate Harmonics & What Are Harmonics?
Harmonics are waveforms which have a frequency which is a whole number multiple of the base frequency of the grid power supply (50Hz).
The effect of the harmonic waveform is to distort the supplied power to connected electrical loads.
Harmonics distortion is a destructive force in a power distribution system.
It creates safety problems, shortens the life span of transformers and interferes with operation of electronic devices.
Generally, electrical systems nowadays are increasingly flooded with non-linear load Variable Frequency Drives, Electronic Power Supplies etc. These devices in the end products cause Harmonic currents to flow into the electrical systems, which in turn leads to heating losses and unwarranted electrical consumption. Reducing the harmonic distortions to an acceptable level can result in savings of approximately 2 to 2.5% in electrical energy cost and the net savings by way of reduced down-times of equipment, derated electrical switchgears, cables and accessories may amount upto 30%. Harmonics are also: Any periodic wave can be described mathematically as a series of sinusoids (sine waves) summed together. This is known as the Fourier series. The sinusoids are integer multiples of the frequency represented by the periodic cycles. Each term in the series is referred to as a "harmonic" of the fundamental frequency (50 Hertz). The term having the same frequency as the fundamental is the first harmonic, and is sometime simply referred to as the "fundamental". The term having twice the fundamental frequency is the second harmonic (100Hz) and so on. What are the consequences of high harmonic distortion levels ? Just as high blood pressure can create stress and serious problems in the human body, high levels of harmonic distortion can create stress and resultant problems for the utility’s distribution system, the plant’s distribution system, as well as all of the equipment that is serviced by that distribution system. The result may be the plant engineer’s worst fear - the shutting down of important plant equipment ranging from a single machine to an entire line or process. Equipment shutdown can be caused by a number of events. As an example, the higher voltage peaks that are created by harmonic distortion put extra stress on motor and wire insulation which ultimately can result in insulation breakdown and failure. In addition, harmonics increase RMS current resulting in increased operating temperatures for many pieces of equipment resulting in greatly reduced equipment life. Harmonic distortion disrupts plants. Of greatest importance is the loss of productivity, throughout and possibly sales. These occur because of process shutdowns due to the unexpected failure of motors, drives, power supplies or just the spurious tripping of breakers. Plant engineers realise how costly downtime can be and pride themselves in maintenance and repair budgets can be severely stretched. For example, every 10oC rise in the operating temperatures of motors or capacitors can cut equipment life by 50%.
Total Harmonic Distortion (THD) is the ratio of Harmonic distortion to the fundamental frequency.
Ideally, Voltage THD should not exceed 5% and current THD should not exceed 20%.
- Variable frequency drives
- DC drives soft starters
- Welders, induction furnaces
- HID lighting, electronic ballasts
- Computers, UPS, copiers, faxes
What are the negative effects of harmonics?
- Additional heat in conductors and other distribution system components.
- Nuisance tripping of circuit breakers or fuses blowing.
- Erroneous operation of control system equipment.
- Electronic communication interference.
- The reverse phase rotation of negative harmonics reduces forward motor torque and increases the current demand.
- Zero sequence harmonics can cause additional heating in the Neutral conductor of 3 phase 4- wire system.
- The Neutral Current Problem.
The Neutral Current Problem: This is a typical problem, where these currents may be 173% larger than the phase conductor currents and are caused by the presence of Triplen harmonics (3rd, 6th, 9th....) and are zero sequence. This means that they have the same relationship in each conductor of a three phase circuit.
Unlike balanced frequency currents, which cancel in the neutral, balanced Triplen currents add arithmetically in the neutral. This can create a hazardous situation, especially in wiring systems with undersized neutral conductors. In the US, the national Electrical Code no longer allows derating of neutral conductors in circuits serving electronic loads.
These neutral currents can cause unwanted MCB (Miniature Circuit Breaker) tripping in the power system; data corruption in computer systems; and unwarranted breakdowns in critical sectors such as hospitals equipment and telecom equipment power systems. The right solution to overcome these problems is to conduct Harmonic Analysis and Audit at these sites, and install Third Harmonic Filters at each of the major loads producing harmonics. Prime Technologies specializes in conducting such audits and specifying, and installing such harmonic filters wherever necessary.
Harmonics and Power Factor Correction In Industrial environments, the addition of Power factor Correction Capacitors in systems present with harmonic generating equipment causes the harmonic current to resonate and grow larger, resulting in major breakdowns of equipment.
We believe that our knowledge in solving Harmonics related problems is unmatched in the Industry, and this gives us a technological advantage when specifying the inclusion of Power Factor Correction Systems, as we always conduct an audit to ensure that harmonic distortions are filtered out through the use of Automatic Harmonic Filters and that the Power Factor Correction Systems provide the savings promised, and not magnify the bad quality of power present in the system, which so commonly occurs.
POWER FACTOR
In AC power systems, Electrical load is comprised of resistive and reactive loads. The resistive component of the load is the one that produces actual work (Active Power). This is measured in Watts or Kilowatts.
The reactive component of energy is alternately stored and returned to the system and is used to charge capacitors or induce magnetic fields. The reactive component does not produce useful work like turning a motor. (Reactive Power)
The combination of Active and Reactive Power Components makes up the Apparent Power that is supplied by the Utility. This is measured in KVA (Kilovolt Amperes)
However, the power utility company still needs to generate and supply the reactive component. This is measured in VAR’s (Reactive Volt Amperes).
And needless to say the utility company also bills for the reactive power demand that the consumers system places on the utility.
Power Factor is a ratio of the Active Power consumed to the Apparent Power supplied by the Utility Company. The utility companies imposes heavy financial penalties on consumers who have inefficient load profiles around the world.
Poor Power Factor translates to high Electricity Bills!
Poor power factor means that equipment and switchgear will usually be rated higher than is necessary and this again comes at a price.
PTINC can offer solutions to measure and analyze load profiles and power factor. We can also design, supply and install Power factor correction capacitor banks.
The Benefits of Power Factor improvement is immediate, measurable and consistent.
- Reduced kVA demand from utility translates directly to the bottom line.
- Reduced load ratings on transformers, switchgear and other electrical equipment.
- Cooler equipment operation
- Longer equipment life.
PHASE IMBALANCE
In an ideal situation a three phase load should be evenly distributed between the phases. This all too often is not the case.
A small voltage imbalance will cause a high current imbalance, overheating would then occur in one or more of the phase windings of a three-phase motor. In some cases the overheating is serious enough to cause motor windings failure due to insulation breakdown.
A single-phase load connected, to a phase, which is out of balance with the other phases will also be subject to heat related problems.
A SAMPLE VOLTAGE AND CURRENT ANALYSIS IS SHOWN BELOW
VOLTAGE SURGES AND DIPS.
The phenomenon of voltage dips and surges is all too familiar to the Electrical Engineering professionals.
A transient surge in the order of milliseconds is enough to destroy electrical equipment.
Even if the failure is not immediate, voltage spikes and dips have the effect of reducing life expectancy, integrity of insulation, safety, reliability and efficiency of electrical equipment.
PTINC can offer solutions for detecting and analyzing the presence of surges and dips in your power supply. If you do not have the correct monitoring equipment in place you may not be able to see a problem coming but you will see the downtime it causes.
PTINC can specify and supply tailor made surge protection solutions.
WHAT IS THE COST OF DOING NOTHING?
When any of the above described power quality and Energy -usage issues are present in a power system the result is:
1. Inefficient plant and process operation.
2. Increased spend on equipment maintenance.
3. Increase in plant downtime.
4. Critical Equipment failure.
5. Reduced lifespan of electrical equipment.
6. Reduced Profit Margins.
WHAT WOULD YOU LIKE TO DO ABOUT YOUR ENERGY USAGE?
- Would you like to reduce your electric power bills?
- Do you want to reduce your peak KVA demand?
- Do you need to add more electrical load to your transformer, but it is already at its maximum capacity?
- Do you have power quality problems associated with harmonics?
- Do you have power quality problems associated with voltage surges and dips?
- Do you have power quality problems associated with phase imbalance?
- Do you have issues with Ground current/ Earth Leakage?
- Do you have unexplained and frequent equipment failure or erratic operation?
- Can you no longer afford downtime, wastage of raw material, time and resources used to restart after unplanned shutdown?
- Do you want to reduce your bills for overtime pay and outsourced labor due to downtime incidents?
TALK TO US TODAY!
WE HAVE A SOLUTION FOR YOU!
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