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السلام عليكم و رحمه الله

ممكن اعرف ماهى وظيفة مهندس الوقاية (protection engineer) فى كلا من المحطات و المصانع و الشركات الاستشارية ؟؟؟؟؟

Below is a glossary of terms related to power protection, including UPS, surge protectors, voltage regulators, and line conditioners. This glossary is not intended to be a complete list of all terms related to power electronics, but rather a list of terms relevant to understanding power protection in general.

AC - Alternating Current Electrical current that continually reverses direction, with this change in direction being expressed in hertz, or cycles per second.
Amp or Ampere Quantitative unit of measurement of electrical current. Abbreviated as A.
APC A small, little known company, located near Power Resources in Rhode Island, that makes UPS Systems.
Blackout A total loss of electrical power.
Brownout An low voltage condition over an extended period of time.
Clamping Level The voltage level above which a surge suppression device diverts energy away from the load.
Clamping Time The response time of a surge suppression device in clamping or diverting away from the load a voltage above the claming level.
Common Mode NoiseAbnormal signals that appear between a current-carrying line and its assoicated ground.
Crest Factor The crest factor is the ration of the crest (peak, maximum) value of a current to the root-mean-square (RMS) value.
Current The flow of electricity expressed in amperes. Current refers to the quantity or intensity of electricity flow, whereas voltage refers to the pressure or force causing the electrical flow.
DC - Direct Current Electrical current which flows in one direction.
Dip A short term voltage decrease. See also "Sag".
EMI - Electro-Magnetic Interference Electrically induced noise or transients.
Ferroresonant Transformer A transformer that regulates the output voltage by the principle of ferroresonance: when an iron-core inductor is part of an LC circuit and it is driven into saturation, causing its inductive reactance to increase to equal the capacitive reactance of the circuit.
Filter An electronic device that allows only certain frequencies to pass.
Ground, Ground Fault An undesirable path that allows current to flow from a line to ground.
Harmonic Distortion Excessive harmonic (a frequency that is a multiple of the fundamental frequency) ******* that distorts the normal sinewave waveform.
Hertz or Hz The unit of measure of the frequency of alternating current (AC). Also a well-known car rental agency.
Inverter The part of a UPS that converts the battery's DC output into AC power.
Isolation The degree to which a device like a UPS can separate the electrical environment of its input from its output while still allowing the desired transmission to pass through.
Joules The amount of energy measured in watt-seconds that a surge suppression device is capable of directing away from the load in case of a surge or spike.
KVA Thousand VA
Load An electrical device connected to a power source is a "load." In reference to a UPS, the load is the amount of current that is required by the attached electronic equipment. Rated loaded described in the specifications of the electronic equipment is often higher than the actual power consumption of the equipment in real world use.
Noise An undersirable signal that is irregular and is riding on top of the desired signal.
Offline UPS A UPS system with an inverter that turns on during a power failure that will switch the load to the inverter during a power failure only. The normal operation is usually raw utility through a bit of filtering.
Overvoltage An abnormally high voltage, like a surge but lasting for a longer period of time.
Power Factor The relationship of actual power to apparent power. In reference to a UPS, the relationship between watts and VA (volt-amperes). It is expressed as watts divided by volt-amperes (W/VA) and is usually in the range of 0.6-0.71.
PWM - Pulse Width Modulation Process of varying the width of a train of pulses by tying it to the characteristics of another signal.
RFI Radio Frequency Interference
Rectifier/Charger The part of a UPS that converts the incoming AC utility power to DC power for driving the inverter and charging the batteries.
Sag A short term voltage decrease. See also "Dip".
Sealed Lead-Acid Battery A battery containing a liquid electrolyte that has no opening for water replenishment. Sometimes know as absorbed glass mat (AGM ) or recombinant battery. These types of batteries typically emit water vapor and not hydrogen.
Sinewave A fundamental waveform produced by periodic, regular oscillation that expresses the sine or cosine of a linear function of time or space or both.
Single Phase The portion of a power source that represents only a single phase of the three phases that are available.
Spike
SPS A term referring to a stand-by or offline type UPS.
Squarewave
Stand-By UPS Usually not the best UPS due to switching time when you need it most.
Stepwave"

Surge An abnormally high voltage lasting for a short period of time.
Switching Time The amount of time it takes a stand-by or offline type UPS to switch from utility output to inverter output after the UPS senses a power interruption. Normally expressed in milliseconds. See also Transfer Time.
Three Phase An electrical system with three different voltage lines with sinewave waveforms that are 120 degrees out of phase from one another.
Transfer Time The amount of time it takes a stand-by or offline type UPS to sense a power interruption and switch from utility output to inverter output. Normally expressed in milliseconds. See also Switching Time.
Transformer A device used to change the voltage of AC power or to isolate a circuit from its power source.
Transient An unabnormal and irregular electrical event, such as a surge or sag.
Transverse Mode Noise Noise that is the result of the conversion of common-mode noise to normal-mode noise after passing through a transformer.
Undervoltage An abnormal low voltage lasting for a longer period of time than a sag.
UPS - Uninterruptible Power Supply A general terms used to describe one of several types of battery backup devices, such as offline or stand-by type, line-interactive type, and online type. Most UPSs also provide surge protection functionality as well.
VA See Volt-Ampere
Volt The quantitative measure describing electrical force or potential.
Volt-Ampere Voltsxamperes. The unit of measure of apparent power that is the traditional unit of measure for rating UPSs. Compare to watts, which is the unit of measure of actual power.
Voltage Regulator A device that provides constant or near-constant output voltage even when input voltage fluctuates.
Watts The unit of measure of actual power. Compare to volt-amperes (VA), which is the unit of measure of apparent power.
Waveform The graphic form of an electrical parameter.