Inside Power Station

The relationship between current and voltage a long one phase of the line in term of the distributed parameters.

R = Series resistance.
G = Shunt conductance.
L = Series inductance.
C = Shunt capacitance.

z = R + jωl = series impedence per unit length/phase.
y = G + jωl = shunt admittance per unit length/phase.
l = length of the line.

Since G is negligible and R is small, high voltage lines are assumed to be lossless when we are dealing with lightning and switching surges. Hence the characteristic impedance Zc with losses neglected is commonly referred to as the surge impedance.

It is equal to (L/C)^1/2 and has dimension of a pure resistance. The power delivered by a transmission line when it is terminated by its surge impedance is known as the natural load or surge impedance load (SIL)

SIL = [(Vo)^2/Zc] Watt

Where Vo is the rated voltage of the line. If Vo is the line to neutral voltage, SIL given by the above equation is the per-phase value. If Vo is the line to line value, the SIL is the three-phase value.


Voltage and current along the length of a lossless line at SIL are given by

V = VR.(e)^ϒx

I = IR.(e)^ϒx

Where ϒ = jβ = jω.(L.C)^0.5

At SIL, transmission line (lossless) exhibit the following special characteristic
1. V and I have constant amplitude a long the line.
2. V and I are in phase throughout the length line.
3. The phase angle between the sending end and receiving end voltages (currents) is equal to βl.

At the natural load, the reactive power generated by C is equal to reactive power absorbed by L, for each incremental length of the line.

Hence, no reactive power is absorbed or generated at either end of the line, and the voltage and current profiles are flat. This is an optimum condition with respect to control of voltage and reactive power.

As we will see the natural or surge impedance loading of a line serve as a convinient reference quantity for evaluating and expressing its capability.

Table below gives typical parameters of overhead lines of nominal voltage.
















For easy to remember appoximate equivalent circuit applicable to an overhead line of 160km (100mi) length and of any voltage rating is shown. For the 500kV line whose parameter are listed in table above with a line length of 160km, we have














XL = 160 x 0.325 = 52 Ω
BC = 160 x 5.20x10^-6 = 8.32 x 10^-4 siemens

Expressed in per unit of Zc (250 Ω)
XL = 52/250 = 0.208 pu
BC = 8.32x10^-4 x 250 = 0.208 pu

Two type of cables are included; direct-buried paper insulated lead covered (PILC) and high pressure pipe type (PIPE).

In 200BC, a Greek named Hero designed a simple machine that used steam as a power source.

He began with a cauldron of water, placed above a fire. As the fire heated the cauldron, the cauldron shell transferred the heat to the water and the water reached the boiling point 100C.

It then changed form and then turned into steam. The steam passed through two pipes into a hollow sphere, pivoted at the both sides. As the steam escaped the sphere through two tubes, each bent at the angle, the sphere moved, rotating on its axis.



Intimately related to steam generation is the steam turbine, a device to change the energy of steam into mechanical work.

In the early 1600s, an Italian named Branca produces a unique invention. He first produced steam, based on Hero's aelopile.

Next, he channeled the steam to a wheel and the steam pressure caused the wheel to rotate. This marked the beginning of steam turbine developed.

Adopted from Steam, its generation and use.

To reach water quality as mention on http://www.anto-hendarto.blogspot.com/2009/10/water-quality.html, after the outage, need several steps as below.


First step is getting a good turbidity and low TSS. Second step after firing is making a good pH by ammonia dosing but still be monitored the conductivity. Also oxygen content need to reduced by opening de-aerator venting valve widely.
















































After the unit get synchronize to grid, our target is going to make a save operation by running the unit with 50% load following with purging the silica. Usually need 12h to get a good water quality for example low silica and low specific conductivity.

After the water quality reach, the unit ready to full load.

This equipment for pick miscellaneous metallic part broken mine tools.



When the speed of the conveyor belt is important (more than 2 m/s).

When the pieces to be extracted are very long and there is the risk to be minted between both bands or when the product coat on the conveyor is very thick, it is interesting to place the over band in the falling of the product on the frump of the head of the main band.

These different conditions make the position of the over band change between two side points.

In the coal fired power plant, magnetic separator which pick up the ferrous matal beside coal. And which non-ferrous metal use metal detector where it would initiate to trip the conveyor if the metal detected.

Metal detector and magnetic separator usually places before the crusher.