China
Africa
Explore chapters and articles related to this topic
Load Tap Changers
Published in Robert M. Del Vecchio, Bertrand Poulin, Pierre T. Feghali, Dilipkumar M. Shah, Rajendra Ahuja, Transformer Design Principles, 2017
Robert M. Del Vecchio, Bertrand Poulin, Pierre T. Feghali, Dilipkumar M. Shah, Rajendra Ahuja
A phase shifting transformer is ideally a transformer with a 1:1 voltage ratio which has the ability to change the phase angle of its output voltage relative to its input. This feature is used by electric power companies to help transfer power more efficiently within the electrical grid. In these transformers, the voltage from the tapped windings is added in quadrature with the input line terminals, producing an effective phase shift in the output. There are quite a few possible connections to achieve this, and some of these are discussed in Chapter 7. Let us just mention here that in a-phase shifting transformer, the tap changer is a key element and the size and rating of the tapped windings are much higher than for conventional transformers.
Load Tap Changers
Published in Robert M. Del Vecchio, Bertrand Poulin, Pierre T. Feghali, Dilipkumar M. Shah, Rajendra Ahuja, Transformer Design Principles, 2017
Robert M. Del Vecchio, Bertrand Poulin, Pierre T. Feghali, Dilipkumar M. Shah, Rajendra Ahuja
A phase-shifting transformer is ideally a transformer with a 1:1 voltage ratio that also has the ability to change the phase angle of its output voltage relative to its input. Electric power companies use this feature to help transfer power more efficiently within the electrical grid. In these transformers, the voltage from the tapped windings is added in quadrature with the input line terminals, producing an effective phase shift in the output. Many connection types are available to achieve this, some of which are discussed in Chapter 7. We will just mention here that the tap changer is a key element in a phase-shifting transformer and the sizes and ratings of the tapped windings are much higher than those for conventional transformers.
Transformer Connections
Published in Leonard L. Grigsby, Electric Power Transformer Engineering, 2017
The development of large, high-voltage power grids has increased the reliability and efficiency of electric power systems. However, the difference of voltages, impedance, loads, and phase angles between paralleled power lines causes unbalanced line loading. The phase-shifting transformer is used to provide a phase shift between two systems to control the power flow. A phase-shifting transformer is a transformer that advances or retards the voltage phase-angle relationship of one circuit with respect to another circuit. In some cases, phase-shifting transformers can also control the reactive power flow by varying the voltages between the two circuits. This application is discussed in Chapter 4.
Determination of Maximum Loadability by a Mixed Complementarity Formulation of the Adjusted Power Flow Problem
Published in Electric Power Components and Systems, 2018
Sunil S. Damodhar, Krishna Suryanarayan
The phase-shifting transformer acts to regulate the active power flow P through the transmission line within the specified minimum value and maximum value . Accordingly, within the control range, the operating point lies inside the rectangle ABCD shown in Figure 4(a). In this work, the control range is chosen to be linear within the rectangle specified by the maximum and minimum phase-shifter angles and the maximum and minimum active powers. Though θp can take only certain discrete values, it is initially assumed that θp is continuous. The linear characteristic is decided as follows. Let the initial operating point be O. Lines DOB′ and D′OB connect the initial operating point with the corners D and B of the rectangle. There are two possibilities as shown in Figure 4(a) and 4(b). Only one of the lines DOB′ and D′OB lies entirely within the rectangle specified by the system data, and this line is considered as the characteristic in the control range. If DOB′ lies within the rectangle, as shown in Figure 4(a), define as the power at B′ and . The resulting characteristic is shown in Figure 4(c). If, on the other hand, D′OB lies within the rectangle, as shown in Figure 4(b), define as the power at D′ and , resulting in the characteristic shown in Figure 4(c). Within its control range, the phase-shifting transformer regulates the active power flow through the transmission line. The additional set of relations due to the presence of phase-shifting transformer is exactly one of the following: where Xs represents the slope of the control range and P0, θp0 are the initial power flow and phase shift, respectively.