Reactive Power Control in Electric Systems. Published in: Electronics and Power (Volume: 29, Issue: , July-August ). Article #. Page(s): A unified approach to the fundamental principles and practices of reactive power control in AC power systems. Emphasizes voltage control, variable loads, and. Download  Reactive Power Control in Electric Systems.
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Such constant-voltage compensators are active compensators and can be synchronous condensers, saturated-reactor compensators, or thyristor-controlled compensators. In the analytical field, attention is focussed on the optimal deof compensators, the relative merits of series and shunt comschemes for long lines, and the modeling of compensators in ower systems on the digital computer. The ideal compensator will not be expected to eliminate harmonic distortion existing in the load current or the supply voltage this function being assigned to an appropriate harmonic filter ; but the ideal compensator would not itself generate any extra harmonics.
Co pensation which can be said to have the objective of modifying Zo Po will be termed surge-inrpedarrce comperrsatioir or Zo-conrpetrsation. The degree to which variations are objectionable depends not only on the magnitude of the light variation but also on its frequency or rate of change, because of the sensitivity characteristics of the human eye. Thus, a direct way of increasing power transfer capacity in transmission systems, and of reducing voltage drop in distribution systems, is to compensate part of the series inductive reactance by series capacitors.
Reactive power control in electric systems (eBook, ) 
A separate reason for the importance of harmonics in a book on reactive power control is that reactive compensation almost always xvii Preface Preface influences the resonant frequencies of the power system, at least locally, and it is important that capacitors, reactors, and compensators be deployed in such a way as to avoid problems with harmonic resonances.
If we take the definition of reactive current as the part that does no work, we are undone by the simple case of a purely sinusoidal voltage applied across a non-linear resistor.
It is during this period that surge arresters, spark gaps, and nonlinear reactors including transformer magnetizing reactances act to prevent extreme voltages which would cause insulation failure. Transient Period, 3. Mallick made several helpful suggestions in connection with Chapters 1 and 2.
The angle between V and Ipis 4. If a short-circuit fault had preceded the line outage and caused the breakers to operate under relay control, the unit’s acceleration would be greater than that caused by merely opening the breakers without the fault.
Reactive power control is an essential tool in maintaining the quality of supply, especially in preventing voltage disturbances, which are the commonest type of disturbance.
The maximum transmissible power in particular is now determined by the “weakest link in the chain,” which is generally the longest section. Reviews User-contributed reviews Add a review and share your thoughts with other readers.
The curves labeled “U” are for the uncompensated line; those labeled “L” apply when the shunt reactor discussed in Section 2. These 14 locations in All: The Transient Period To illustrate the electrical behavior of a system during this period, consider one phase of the positive-sequence eystems circuit of a twomachine system in Figure 3a. Operation is at point C in Figure On shorter lines, or on sections of line between unswitched reactors, the overvoltage problem is less severe and the reactors may be switched frequently to assist in the hour-by-hour management of reactive power as the t.j.e.millre varies.
Future Developments and Requirements, 5. Also shown is the variation transmission angle that would be obtained without compensation. The reactive load line is shown in Figure 8b.
Unbalanced operation gives rise to components of current in the wrong phase-sequence i. There is a fundamental and important interrelation between active and reactive power transmission.
In an actual compensator, the value would be determined automatically by a control loop.
Reactive Power Control in Electric Systems
Please enter your name. The theory would apply with circuit resistances and charging included, and these assumptions are made for ease of illustration only. There will be a transmitted power above which it is uneconomic to provide the necessary reactive power, and at this level alternatives may need to be considered [e.
Here xlSh and by, are the reactance and susceptance per mile of the shunt compensating inductance. The reason is that, immediately following a disturce, the voltages and currents are not pure sine waves. Open to the public N ; Transient Period The concept of the system’s reactive load line, introduced in Chapter 1 to describe the quasi-steady state, can be extended to visualize the effect of fixed capacitors and reactors on the positive-sequence component of voltage during other transition periods, including the transient period.
Wireless Power Transfer Naoki Shinohara. Cooling System, 5.
Reactive Power Control in Electric Systems
These 2 locations in Western Australia: The Uncompensated Line Under Load: As applied on transmission systems, the TCR includes a clos ltage regulator and thyristor gating-angle control system.
This promising new subject is given the last word in leaving the reader to the future. Lower include a comma in your tag, surround the tag with double quotes. Protection arrangements for the compensator and coordination electfic other protection systems, including reactive power limits if necessary. The voltage profile, the maximum transmissible power, and the reactive power requirements of each section can then be determined separatelythe problems in each independent section being less severe than in the line as a whole.
That is, instead of acting as a voltage regulator, the compensator acts as a power-factor corrector. Uncorrected voltage deviations, even if temporary, may lead to an outage or damage to utility or consumer-owned equipment.
Search WorldCat Find items in libraries near you. University of Queensland Library. This equation tells how B, must vary with the transmission angle 6 in order to maintain the midpoint voltage equal to Em. If they are to correct for momentary half-second overvoltages or voltage dips, they must be switched on or off rapidly, and in some cases in a repeated manner.