Engineering

PRIMARY SECONDARY AND TERTIARY FREQUENCY CONTROL

PRIMARY CONTROL:Primary control consists of changing a generating unit’s power versus the frequency, according to its static generation characteristic as determined by the speed governor settings.The objective of primary control is to re-establish a balance between generation and demand within the synchronous area at a frequency different from the nominal value. This is done at…

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ADVANTAGES OF THE THYRISTOR CONTROLLED SERIES CAPACITOR

Use of thyristor control in series capacitors potentially offers the following little-mentioned advantages:1. Rapid, continuous control of the transmission-line series-compensation level.2. Dynamic control of power flow in selected transmission lines within the network to enable optimal power-flow conditions and prevent the loop flow of power.3. Damping of the power swings from local and inter-area oscillations.4.…

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SYNCHRONOUS CONDENSER

A Synchronous Condenser is a device that control voltage on an electric utility’s transmission or distribution system. Voltage is the “pressure” needed to deliver electricity through such a system.Another device that controls voltage is a capacitor. Capacitors have no moving parts. Their simple design keeps their cost and maintenance requirements low.Synchronous Condensers have internal parts…

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BENEFITS OF VSC BASED TRANSMISSION SYSTEM

Voltage Source Converter (VSC) technology has been selected as the basis for several recent projects due to its controllability, compact modular design, ease of system interface and low environmental impact. Following are few factors which increase use of Voltage Source Converter in transmission system.Independent control of reactive and active power.Reactive control independent of other terminal(s).Simpler interface with ac…

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PRINCIPLE OF OPERATION OF UNIFIED POWER FLOW CONTROLLER UPFC

UPFC consist of two back to back converters named VSC1 and VSC2, are operated from a DC link provided by a dc storage capacitor. These arrangements operate as an ideal ac to ac converter in which the real power can freely flow either in direction between the ac terminals of the two converts and each…

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UNIFIED POWER FLOW CONVERTER UPFC

UPFC concept was proposed by GyuGyi in 1991. The UPFC was devised for real time control and dynamic compensation of ac transmission systems. It provides multifunctional flexibility to solve many of the issues facing the power delivery industries. UPFC is able to control synchronic or individually all the parameters (i.e. voltage, phase angle, and impedance)…

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OPERATING MODES OF UNIFIED POWER FLOW CONTROLLER UPFC

The UPFC has many possible operating modes. In particular, the shunt inverter is operating in such a way to inject a controllable current, Ish into the transmission line. The shunt inverter can be controlled in two different modes:1) VAR CONTROL MODE:The reference input is an inductive or capacitive VAR request. The shunt inverter control translates…

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NEED FOR FACTS DEVICES

Since the development of interconnection of large electric power systems, it has been the spontaneous system oscillations at very low frequencies in the range of 0.2–3.0 Hz. After starts, it would continue for a long period of time. In certain cases, it continues to develop causing system separation due to the lack of damping of…

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FACTS TECHNOLOGY

The FACTS technology is not represented by a single high-power controlling device, but it is a collection of all the controllers, these individually or in coordination with the others give the possibility to fast control one or more of the interdependent parameters that influence the operation of transmission networks. These parameters include e.g. the line…

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INTERLINE POWER FLOW CONTROLLER IPFC

Recent developments of FACTS research have led to a new device: the Interline Power Flow Controller (IPFC). This element consists of two (or more) series voltage source converter-based devices (SSSCs) installed in two (or more) lines and connected at their DC terminals. Thus, in addition to serially compensate the reactive power, each SSSC can provide…

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APPLICATIONS OF HIGH VOLTAGE DC TRANSMISSION

1) CONNECTING REMOTE GENERATIONSome energy sources, such as hydro and solar power, are often located hundreds or thousands kilometers away from the load centers. HVDC will reliably deliver electricity generated from mountain tops, deserts and seas across vast distances with low losses. 2) INTERCONNECTING GRIDSConnecting AC grids is done for stabilization purposes and to allow…

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CLASSIFICATION OF HVDC LINKS

HVDC links may be broadly classified into the following categories:Monopolar LinksBipolar LinksHomopolar LinksThe basic configuration of a monopolar link is shown in figure. It uses one conductor, usually of negative polarity. The return path is provided by ground or water. Cost considerations often lead to the use of such systems, particularly for cable transmission. This…

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COMPONENTS OF HIGH VOLTAGE DC TRANSMISSION SYSTEM

Figure: A schematic of a bipolar HVDC system identifying main components

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Importance of Reactive Power for System

Introduction: We always in practice to reduce reactive power to improve system efficiency .This are acceptable at some level. If system is purely resistively or capacitance it make cause some problem in Electrical system. Alternating systems supply or consume two kind of power: real power and reactive power. Real power accomplishes useful work while reactive…

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Electrical Energy Saving Tips

How to save  Electrical energy at Home In our home we use lot of electrical equipment like Tv, Freeze, Washing machine,Mp3 player. music system, computer laptop. But we have not adequate knowledge for how to use this electrical equipment in proper way Due to this ignorance we are paying more electricity Bill which we are…

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