HVDC links may be broadly classified into the following categories: Monopolar Links Bipolar Links Homopolar Links The 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 […]
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Figure: A schematic of a bipolar HVDC system identifying main components
COMPONENTS OF HIGH VOLTAGE DC TRANSMISSION SYSTEM Read More »
1) CONNECTING REMOTE GENERATION Some 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 GRIDS Connecting AC grids is done for stabilization purposes and
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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 compensating the reactive power, each SSSC can provide
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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
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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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
OPERATING MODES OF UNIFIED POWER FLOW CONTROLLER UPFC Read More »
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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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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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
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