Thursday, September 17, 2015

Lighting terminology

Panasonic.net

Some of the terminology used in lighting practice and analysis, and in studying the environmental effects of light, are not commonly used elsewhere, or have different meanings when used in this context. Some terms are commonly used when talking about lighting practice, but have different meanings to different people; this is a frequent source of talking cross-purposes in our field.

Corona Phenomena

The electric transmission grid represents a network that serves to the transmission and the interregional exchange of electric energy.

Within the transmission network is made an energy balance that takes into account the network losses.

System losses are:

• Power losses (ΔP) represent the consumption of electric power necessary for the transmission of electricity and for the distribution process;

• Energy losses (ΔW) represent the consumption of electric energy necessary for the transmission of electricity and for the distribution process;

Soft Starter

Schneider softstarter

Motors that run typical industrial applications employing conveyors, pumps, blowers, and compressors all have one common quality , they draw a large amount of current when they start up, perhaps six times what they draw during normal operation. This level of current can stress motor components and cause power quality issues on plant electrical systems, particularly for larger motors of 1 hp or more. That is why motors of this size frequently employ soft starting.

Air Circuit Breaker

Schneider Electric (NW&NT) air circuit breaker

Air Circuit Breaker (ACB)

The type of circuit breaker, which operates in air (where air-blast as an arc quenching medium) at atmospheric pressure, is known to be an Air Circuit Breaker. Air circuit breaker has completely replaced by oil circuit breaker. In different countries, still it is a preferable choice to use an Air circuit breaker up to 15KV because, there is no chance of oil fire like in oil circuit breaker.

Harmonic and capacitor selection

Effects of Harmonics

Schneider Capacitor

Harmonics in electrical installation

The presence of harmonics in electrical systems means that current and voltage are distorted and deviate from sinusoidal wave forms.

Harmonic currents are currents circulating in the networks and which frequency is an integer multiple of the supply frequency.

Improving the PF can maximize current-carrying capacity, improve voltage to equipment, reduce power losses, and lower electric bills. The simplest way to improve power factor is to add PF correction capacitors to the electrical system. PF correction capacitors act as reactive current generators. They help offset the non-working power used by inductive loads, thereby improving the power factor. The interaction between PF capacitors and specialized equipment, such as variable speed drives, requires a well-designed system.

Power Factor

Loads in electrical distributer systems are inductive Loads which need a magnetic field to operate, Such as motors, transformers, ballasts and furnace.

In first we should know what is the two kinds of power that be needed in the inductive loads;

Conductors & Stranded Types

Conductors

Conductors have the function of getting electricity from one point to another in an electrical circuit.

Copper and aluminum are the main materials discussed because of their balance between high conductivity and reasonable price.

MCCB & Trip Unit

What is a Circuit Breaker?

Schneider Electric

The definition of a circuit breaker varies between the standards organizations, but the most commonly used definitions are:

Defines circuit breakers as “devices designed to open and close a circuit by non-automatic means, and to open the circuit automatically on a predetermined overcurrent without injury to itself when properly applied within its rating.

a mechanical switching device, capable of making, carrying and breaking currents under normal circuit conditions and also making, carrying for a specified time and breaking currents under specified abnormal circuit conditions such as those of short-circuit.

MCB

What is The MCB ?

Schneider Electric

The definition of MCB is Miniature Circuit Breaker . MCB is electromechanical device which is used to protect electrical circuit from the overcurent which may caused due to ( short circuit , overloads or faulty design). It interrupts the continuity of electrical flow through the circuit once a fault is detected . now we can define the MCB as a switch which automatically turns off when the current flowing through it passes the maximum allowable limit.

Centrifugal Pumps ( Part 2)

We talk in the part one about Centrifugal Pumps . Now we complete in the second part the other Centrifugal Pumps parts.

Motor Starting Method (1- DOL Method )

When a motor is switched on , there is a high inrush current from the mains, ( The starting current of an AC motor can vary from 3 to 8 times the nominal current). The high current drawn from the network can cause problems such as voltage drop, high transients and, in

Schneider Electric DOL

some cases, uncontrolled shutdown. High starting current also causes great mechanical stress on the motor’s rotor bars and windings, and can affect the driven equipment and the foundations. Several starting methods exist, all aiming to reduce these stresses To overcome this , There are several starting systems which differ according to the motor and load specifications. The choice is governed by electrical, mechanical and economic factors. The kind of load driven is also important in the choice of starting system.

LED Technology

LEDs

Light emitting diodes, These are electronic components that produce light by conversion of electrical energy directly to light by the movement of electrons within the material of the diode. They are important because due to their efficiency and low energy, they are beginning to replace most conventional light sources.

The P-N junction is the basis of the functioning of the LED. The LED has an anode and a cathode separated by a crystal of semiconductor material. Addition of impurities to the semiconductor material produces P-N junctions within the chip. The entire assembly is housed within a plastic cover that can also double up as a lens to guide the light emitted by the LED.

Centrifugal Pumps ( Part 1)

The centrifugal pump is the most used pump type in the world. The principle is simple, well-described and thoroughly tested, and the pump is robust, effective and relatively inexpensive to produce. There is a wide range of variations based on the principle of the centrifugal pump and consisting of the same basic hydraulic parts.

What is the Pump

What is the pump :

pumps are mechanical devices that impart energy to a fluid .They are not only very useful, but are excellent examples of hydrostatics. Irrigation Pumps lift water from one elevation to a higher level , overcome friction losses during conveyance , provide pressure for sprinkler operation , and inject chemicals into irrigation systems . Irrigation pumps use mechanical energy to increase the potential pressure and kinetic energy of the irrigation water .

Lighting Behavior:

- Reflection
- Absorption
- Transmission
- Refraction
- Interference

Lighting Basics

What is the Lighting ?

Light is that part of the electromagnetic spectrum that is perceived by our eyes. The wavelength range is between 380 and 780 nm.

Synchronous motor

Synchronous motor and induction motor are the most widely used types of AC motor. Construction of a synchronous motor is similar to an alternator ( Ac Generator ) . A same synchronous machine can be used as a synchronous motor or as an alternator. Synchronous motors are available in a wide range, generally rated between 150kW to 15MW with speeds ranging from 150 to 1800 rpm.

Induction motors are the most commonly used electrical machines. They are cheaper, more rugged and easier to maintain compared to other alternatives.

Single Phase Induction Motor

Single Phase Induction Motor

The single-phase induction machine is the most frequently used motor for refrigerators, washing machines, clocks, drills, compressors, pumps, and so forth.
The single-phase motor stator has a laminated iron core with two windings arranged perpendicularly.
One is the main and The other is the auxiliary winding or starting winding

Motors

Motors vs Engines

• Motors convert electrical energy to mechanical energy.
• Engines convert chemical energy to mechanical energy.

UNITS OF ELECTRICAL MEASUREMENT

System Internationale (SI) Metric System

Electrical units of measurement are based on the International (metric) System, also known as the SI System. Units of electrical measurement include the following:

Ampere

Volt

Ohm

Siemens

Watt

Henry

Farad

ELECTRICAL TERMINOLOGY

Knowledge of key electrical terminology is necessary to fully understand principles in electrical science.

Analysis of One MW Photovoltaic Solar Power Plant Design

· Major Components of PV System.

1. PV Module.

2. Solar Charge Controller.

3. Inverter.

4. Battery Bank.

5. Load.

The Transformer

The principle parts of a transformer and their functions are:

• The core, which makes a path for the magnetic flux.

• The primary coil, which receives energy from the ac source.
• The secondary coil, which receives energy from the primary winding
and delivers it to the load.
• The enclosure, which protects the transformer from dirt, moisture, and
mechanical damage.

Electrical power Transmission Line

Flip on the lights, and you’re completing a circuit that connects your light bulb to the wires that serve your house, to the larger wires that serve your neighborhood and, ultimately, to a network of high capacity wires that deliver power over great distances. This network the power transmission system is complex, costly and critical to the nation’s economy and way of life. Many of those who influence the electric industry, however, lack a good understanding of the transmission system.

What is the power plant ?

A power plant is and industrial location which is used for the generation and distribution of electrical power .

Types of power station ?