An example showing the improvement of power factor by installing capacitors is shown below:

Example 1. A chemical plant installed a transformer 1500 KVA . The plant needs in the first 1160 KVA with power factor 0.70. The percentage of transformer loading about 78 percent (1160/1500 = 77.3 percent). To improve the power factor and to avoid penalties by electricity suppliers, the plant adds approximately 410 kVAr the motor load. This improves the power factor up to 0.89 and this can reduces the KVA that required becomes 913 KVA , which is the sum vector of KVAR and KW. 1500 kVA transformer and then only under load 60 % from the capacity. So that the plant will be able to increase the load on the transformer in the future

Example 2. A group of incandescent lamps with a voltage of 220V/58 W, coupled with a fluorescent lamp 12,, 11 W, there are 30 pieces of incandescent and fluorescent lamp. Power factor measured by cos alpha1 = 0.5. Calculate the apparent power of the load and the magnitude of current I1 before the compensation, if desired work factors becomes cos alpha2 = 0.9. Calculate the magnitude of current I2 (after compensation).

1. The amount of the combined light

PG = (58 W x 18) + (11 W x 12) = 1176 watts = 1.176 KW

Cos phi 1 => PG/S1 > S1 => Pg / Cos phi 1 => 1.176 KW/ 0.5 => 2.352 kVA.

I1 = S1 / U = 2.352 V = 10.69 kVA/220 ampere (A) -> before compensation

2. The amount of power after compensation (cos phi = 0.9)

S2 = PG / Cos phi2 = 1.176 kW / 0.9 = 1.306 kVA

Then I2 = S2 / U = 1.306 V = 5.94 kVA/220 A -> after compensation

In alternating current system there are three types of power that must be known, especially for load impedance (Z), namely:

• The pseudo-(S, VA, Volt Ampere)
• The active Power (P, W, Watt)
• The reactive power (Q, VAR, Volt Ampere Reactive)

For AC power circuit, the voltage waveform and sinusoidal current, the amount of power is not same in every time. Then the power which is the average power measured in Watts, this power form the active energy per time unit and can be measured with a kWh meter and also the real power or active power (shaft power, real power) used by load to perform a specific task.

While the apparent power is expressed in units of Volt-Ampere (abbreviated, VA), stating the capacity of electrical equipment, as indicated on the generator and transformer equipment. At some installations, particularly in factories / industries there are also certain expenses such as electric motors, which require other forms of power, i.e. reactive power (VAR) to create a magnetic field or in other words, the reactive power is used as an energy power generating magnetic flux, so causing the magnetization and this power is restored to the system due to the effects of electromagnetic induction itself, so that power is actually a load (demand) in an electric power system.

Understanding Power Factor

Power factor is the ratio between active power (watts) to apparent power / total power (VA) or the cosine corner between active power and apparent power / total power. High reactive power will increase this corner, and as a result, the power factor will be lower. The power factor is always less than or equal to one.

Theoretically, if the entire load power is supplied by the power company has a unity power factor then, the maximum power that transferred is equivalent to the capacity of the distribution system. So, the load-induced and if the power factor ranged from 0.2 to 0.5, then the electricity distribution network capacity to become depressed. So, reactive power (VAR) should be as low as possible for the same kW output in order to minimize total power requirements (VA).

Power factor describes the phase corner between the active power and apparent power. Low power factor detrimental because it resulted in a high load current. This power factor improvement is using a capacitor.

If this happens, one thing to consider is a history of exposure to the tools that give rise to electromagnetic radiation. There is the possibility of electrical interference sensitivity. Electrical sensitivity is a physiological disorder with neurological signs and symptoms as well as sensitivity, a variety of symptoms and complaints.

This disorder is usually caused by electromagnetic radiation from high voltage power lines or extra high, home electronic appliances, office and industry. Including cell phones (mobile phones) and microwave oven, it potentially raises a variety of complaints.

“Electrical sensitivity”

In fact has long been concern in the community would arise negative effects of electromagnetic radiation on health, especially with the growing use of non-ionizing radiation sources. Man-made sources of non-ionizing radiation such as high voltage power lines as well as extra high, laser, radar, microwave ovens, cell phones, and so on. Seldom realized that the highest risk from non-ionizing radiation sources it comes from nature, the sun’s ultra violet rays

Potential health problems, which arise due to exposure to electromagnetic field can occur in various body systems, among others: (1) the blood system, (2) the reproductive system, (3) the nervous system, (4) the cardiovascular system, (5) endocrine system, (6) psychological, and (7) hypersensitivity. While manifestations from hypersensitivity is also known by the term electrical sensitivity, which describes the physiological disorders of neurological signs and symptoms as well as sensitivity to electromagnetic fields, with typical symptoms.

Even some cases of electrical shock can result in death. Why 12 Volt power supply voltage on the accumulator do not sting and dangerous to humans? Because the human body has a safety limit for electricity, some studies say up to 50 miliampere (mA) electric current, is the safe limit for humans.

The heart as an organ of the body most vulnerable to the influence of electrical current flow and there are four boundaries if we are exposed to electric shock.

• Region 1 (0.1 to 0.5 mA), the heart is not affected at all even in the long term.
• Region 2 (0.5 to 10 mA), the heart reacts and tingling appear on the surface of the skin. Above 10mA to 200mA, the heart resistant to a maximum period of 2 seconds.
• Region 3 (200 up to 500mA), heart felt a strong shock and pain, if the past 0.5 seconds into the danger area.
• Region 4 (above 500mA), the heart will be broken and can permanently damage the circulatory system and even result in death.

AC power source, current flows into the human body at Ik, past the prisoner’s hand touch, Ruth, RKI human body, and the prisoners Ru2 footrest. Prisoners of the average human body Ώ 1000, the current that is safe for the human body is a maximum of 50mA, then the magnitude of touch voltage is equal to:

UB = Rk. Ik = 1000 Ώ x 50 mA = 50 V

Well…! all been answered why the accumulator voltage 12V do not sting when we held positive terminal and negative terminals, because the human body just feel the influence of electrical voltage is above 50V.

The story above is not a figment or myth about open source but a real incident that occurred in Australia. Integral Energy is the second largest of electrical provider in Australia. Concerns about virus attacks, hacker, or cyber terrorists from another country that would attack the country’s vital object have been the concern of some in the Australian government. In fact, they are also concerned about the use of Windows in infrastructure that is critical and vital.

In this integral Energy case, it turns out a lot of Windows-based computers in the network of Integral Energy which had been infected with the virus and must be rebuilt.

I hope the experience from another countries serve as a lesson for managers of existing power plants across the country in the world, especially those already integrated control system and Windows-based computers that are used. Because it is possible, it occurs also in some countries, due to disappointment over the performance of electrical companies, as the sole operator of electrical energy in a country, which is considered by most people, are still not able to provide electrical energy as needed.

The cable is one component of the network owned by electric utilities. Besides cable, small stations, transformers, electricity generator, and the other devices of connective to carry the electricity from electricity generation to the some homes or office.

When the electrical left the generation, he move to the substation, then its distributed to the wire that have high of voltage transmission. When it is used to transmit the broadband connection, a high voltage cable which is the first barrier. Electricity that flows on the transmission cable can be a high-voltage about 150 kV or even extra-high voltage above 500 kV. The magnitude of this voltage is not suitable for transmitting data.

As noted above, the electric current and RF use different frequencies. In order the data can be transmitted clearly from one point to another, then the required line, which supports the radio spectrum to vibrate without interferenced by other sources. Hundreds of thousands of volts of electricity does not vibrate at a fixed frequency. Electric current in the amount bulldoze all of the spectrum, and when moving in the RF spectrum used, it is certain signal transmission will drop or even fall apart.

BPL bypasses this problem by avoiding the use of high-voltage cable joint. This system lowers the voltage data to 7200 volts, or equal to the voltage supplied to the medium-voltage cables.

Yet by using power lines as the last mile, internet penetration would have been banded (broadband) would be much more effective and equitable. With Broadband over Power Line technology (BPL), anyone staying plugged into any PC socket (electrical outlet), and instantly be able to immediately enjoy high-speed internet. By combining the principles of radio technologies, wireless networking and modems, developers can create a way to transmit data over power lines to residential and office space with speeds ranging from 500 Kbps to 3 Mbps (equivalent to a speed DSL).

With a few modifications to the electrical cable, BPL developers could work with electricity providers and ISPs (Internet Service Provider) to bring broadband connections to every customer. At this point, the proposal to make electrical wiring as the last mile service offers two types, namely:

-          Connect electrical devices in your home or office.

-          Access BPL will bring broadband connection using a cable, and allows electric utilities to control the electrical system in your home or office.

High-speed data transmission using electrical cable, posing a potential to connect all the electrical devices are plugged in or connected inside the house. Imagine if the electrical devices you have at home or auto power timer, such as home alarm, light switches, coffee maker or even a washing machine can communicate with each other via a high-speed internet connection. The morning will look completely different.

• Electrolytic copper, which must satisfy some normalization condition, both the electrical conductivity and the mechanical properties.

• Brons, who has greater mechanical strength, but has a low electrical conductivity. Often used for grounding wire.

• Aluminium, which has advantages because the material is so light. The drawback is the rather low electrical conductivity and wires a little stiff. The price is very competitive. Therefore a serious rival for the copper and it can be said that in practice are now beginning to be more widely used for electrical installations of the new strong currents from the use of copper.

• Aluminium steel core, which is usually known as ACSR (Aluminium Cable Steel Reinforced), an aluminum conductor cable that comes with the unit at the core of steel wire cord. Steel wire was necessary to increase the tensile strength of the cable. ACSR is widely used to wire channels air conductivity.

• Aldrey, kind of a mixture of aluminum wire with a silicium (concentration about 0.4% – 0.7%), Magnesium (concentrations between 0.3% – 0.35%) and ferum (concentrations between 0.2% – 0, 3%). This wire has a very large mechanical strength, but rather low electrical conductivity.

• Cooper-weld, steel wire surrounding a given layer of copper.

• Steel, the most widely used materials as well as wire lightning and grounding wire.

Based on the above overview, it can be said that the most important material for the channel is electrically conductive copper and aluminum, so that both materials are widely used as a wire conductor of electricity, either air or cable channel conductivity of the soil.

For those who are still less understand what’s the frequency? I try to give an overview in this article.

Frequency is the characteristic of the voltage which is generated by the generator. So when it says 50 Hz frequency, mean voltage generator which produced a change in value over time, its value is changed repeatedly as many as 50 cycles per second.

So the voltage from zero to a maximum (+) and then zero again and then to the maximum value but its direction reversed (-) and then zero again and so on (if represented by a graph will form a sinusoidal wave) and this happens once in a fast-time, 50 cycles in one second. So if we look at electrical loads such as lights, in fact has been repeatedly lost its voltage (zero) but because it occurred within a very fast then the light is still alive.

So if we observe this phenomenon and try to experiment, let’s create that if the frequency is low, we take such a conservative who Hz, what happens then everyone second voltage will be lost and then the light will appear to the death over and over again like a light flip-flop (see animation on the right).

From the above analysis we can conclude that the appeal to the stability of the electrical load required on high frequency voltage to be completely smooth (do not feel life and death).

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