qr code vb.net library Magnetic Coupling. Transformers in Visual Studio .NET

Encoder Code 128 Code Set A in Visual Studio .NET Magnetic Coupling. Transformers

CHAPTER 10 Magnetic Coupling. Transformers
Decode Code-128 In .NET Framework
Using Barcode Control SDK for VS .NET Control to generate, create, read, scan barcode image in VS .NET applications.
USS Code 128 Maker In Visual Studio .NET
Using Barcode creation for .NET Control to generate, create Code 128B image in Visual Studio .NET applications.
The Three-Phase Power System. Introduction
Code 128 Code Set A Recognizer In VS .NET
Using Barcode decoder for VS .NET Control to read, scan read, scan image in VS .NET applications.
Create Bar Code In Visual Studio .NET
Using Barcode drawer for Visual Studio .NET Control to generate, create bar code image in VS .NET applications.
Let us begin with the ordinary single-generator, two-wire, ac circuit of Fig. 245.
Reading Barcode In .NET Framework
Using Barcode scanner for .NET framework Control to read, scan read, scan image in VS .NET applications.
Creating Code 128 Code Set B In Visual C#
Using Barcode generation for VS .NET Control to generate, create Code 128 Code Set A image in .NET applications.
Fig. 245
Drawing Code 128 Code Set C In .NET Framework
Using Barcode maker for ASP.NET Control to generate, create Code 128 Code Set A image in ASP.NET applications.
Encode USS Code 128 In VB.NET
Using Barcode drawer for VS .NET Control to generate, create Code 128 Code Set A image in .NET applications.
We ll refer to this as a single-phase circuit, in which the basic equations for current and power are " " " I V =Z L and P VI cos 
Bar Code Generator In Visual Studio .NET
Using Barcode drawer for Visual Studio .NET Control to generate, create barcode image in .NET applications.
Draw Barcode In Visual Studio .NET
Using Barcode drawer for .NET framework Control to generate, create barcode image in .NET applications.
" " where V and I denote the magnitudes of the rms vector quantities V and I , and where  is " and I vectors. " the phase angle between the V The single-phase circuit of Fig. 245 is, of course, very basic and much used in lowpower applications. It is, however, not well-suited for the generation and transmission of large amounts of power, nor for the operation of large industrial-type ac motors. Thus, instead of the simple single-phase circuit of Fig. 245, almost all commercial electric power is generated and transmitted using what is called the three-phase system.* There are important reasons for this. One is that the overall generation and transmission e ciency of three-phase systems is considerably higher than that of single-phase systems. Another reason (as we ll show later on) is the fact that the INSTANTANEOUS POWER in a balanced three-phase system is constant, which is completely unlike the pulsating form of power in a single-phase system. This is an important advantage in the operation of high-horsepower ac motors. Also, in regard to the much-used single-phase system of Fig. 245, there are three such single-phase circuits available in a three-phase circuit. Three-phase power is produced by a three-phase generator, which can basically be described as follows. A three-phase generator fundamentally consists of three separate but identical SINGLE-PHASE GENERATORS rigidly attached to a common shaft. The three generators produce EQUAL MAGNITUDES OF RMS VOLTAGE of the same frequency, but the three sets of windings are positioned on the shaft so that there is a PHASE DISPLACEMENT OF 120 DEGREES between the three single-phase voltage waves. The three separate generators are then connected together to form ONE COMPLETE, SYMMETRICAL, SINUSOIDAL THREE-PHASE GENERATOR. In regard to the last statement, let us note that the three component generators will be connected together to form either a Y-connected generator or D-connected (deltaconnected) generator. These two basic generator connections are shown in Figs. 246 and
Drawing Bar Code In .NET Framework
Using Barcode drawer for VS .NET Control to generate, create barcode image in .NET framework applications.
Generate UPCE In VS .NET
Using Barcode creator for .NET framework Control to generate, create UPC - E1 image in .NET framework applications.
* FREQUENCY is understood to be 60 cycles/second (60 Hz), ! 2f 377 rad/sec.
Generate GTIN - 13 In Visual C#.NET
Using Barcode generation for VS .NET Control to generate, create GTIN - 13 image in VS .NET applications.
European Article Number 13 Generator In Visual Studio .NET
Using Barcode creator for ASP.NET Control to generate, create UPC - 13 image in ASP.NET applications.
CHAPTER 10 Magnetic Coupling. Transformers
Code 128B Recognizer In .NET Framework
Using Barcode decoder for .NET Control to read, scan read, scan image in .NET framework applications.
Make Code39 In VB.NET
Using Barcode creation for Visual Studio .NET Control to generate, create Code 39 Full ASCII image in .NET framework applications.
Fig. 246. Y connection.
DataMatrix Maker In Java
Using Barcode printer for Android Control to generate, create DataMatrix image in Android applications.
Print EAN / UCC - 13 In None
Using Barcode generation for Font Control to generate, create UCC.EAN - 128 image in Font applications.
Fig. 247. D connection.
Make Bar Code In Java
Using Barcode encoder for Eclipse BIRT Control to generate, create barcode image in Eclipse BIRT applications.
DataMatrix Printer In None
Using Barcode maker for Office Excel Control to generate, create Data Matrix image in Microsoft Excel applications.
" " " 247, in which Va , Vb , and Vc are the three single-phase voltages which, from now on, will be called the PHASE VOLTAGES. In the above, A, B, and C denote the OUTPUT TERMINALS of the three-phase generators. These three terminals will be connected, by means of a three-wire transmission line, to a three-phase load. A three-phase system is thus basically a three-wire system, driven by three interconnected single-phase generators of the same frequency and same rms voltage but with phase di erences of 120 degrees. A three-phase generator satisfying these conditions is said to be a BALANCED generator.
Y-Connected Generator; Phase and Line Voltages
In all of our work we ll assume a Y-connected type of generator, since this is normally the connection used in three-phase power generation, and we ll assume the generator to be completely balanced, unless speci cally stated otherwise. (The load impedance, however, can be of either the Y-type or the D-type.) This is illustrated in Fig. 248, in which a balanced Y-connected generator is connected to a balanced three-phase load. (The load is said to be balanced because all three
Fig. 248
CHAPTER 10 Magnetic Coupling. Transformers
" impedances are given to have the same value of Z ohms.) In the gure we ve used, for the purpose of comparison, both the standard arrow notation and the double-subscript notation to denote the positive direction of the rms voltage and current vectors relative to some particular reference vector. * In this section we wish to nd the relationships between the PHASE VOLTAGES and the LINE VOLTAGES, the line voltage being the voltage between any two output " " " lines (shown as VAB , VBC , and VCA in the gure). With this in mind, let us concentrate our attention on the generator end of the gure, paying special attention to the subscript notation, in which SMALL subscript letters denote PHASE voltages and LARGE subscript letters denote LINE voltages. Let us take the junction point n as the common reference point in the system. The three individual vector phase voltages are then given with respect to the point n. Thus, if " we take the phase voltage Vna to be the reference vector, then let us agree that, by de nition, we have " Vna Vna =08 where Vna Vnb Vnc Vp because it is given that the phase voltages all have EQUAL MAGNITUDES. Thus the relationships in eq. (421) can be written as " Vna Vp =08 " Vnb Vp = 1208 " Vnc Vp = 2408 422 " Vnb Vnb = 1208 " Vnc Vnc = 2408 421
where Vp is the MAGNITUDE of the phase voltages. Now, in the gure, imagine the junction point n to be the origin of the complex plane, and that Vna lies on the positive x-axis. Then the quantities in eq. (422) could be written in the complex rectangular form Vp cos  j sin  ; thus, using degrees, and remembering that cos  cos  and sin  sin , " Vna Vp cos 0 j sin 0 Vp " Vnb Vp cos 120 j sin 120 Vp cos 120 j sin 120 0:5 j0:8660 Vp " Vnc Vp cos 240 j sin 240 Vp cos 240 j sin 240 0:5 j0:8660 Vp 425 424 423
Let us now look VERY CAREFULLY at Fig. 248, beginning with the two lines A and B, shown again in Fig. 249. " In Fig. 249, note that VAB is the voltage drop from line A to line B. If, now, we choose to start at A and trace around the loop in the cw sense (following the usual rule of setting the vector sum of the voltage drops equal to the vector sum of the generator voltages), we have that " " " VAB Vnb Vna Then, upon making use of eqs. (424) and (423), you should nd that " VAB 1:5 j0:8660 Vp
Copyright © OnBarcode.com . All rights reserved.