Series and Shunt Compensation of Transmission Lines: The performance of long EHV AC transmission systems can be improved by reactive compensation of series or shunt (parallel) type. Series capacitors and shunt reactors are used to reduce artificially the series reactance and shunt susceptance of lines and thus they act as the line compensators. Series and […]
Series and Shunt Compensation of Transmission Lines Read More »
Methods of Voltage Control in Transmission Lines: Practically each equipment used in power system are rated for a certain voltage with a permissible band of voltage variations. Voltage at various buses must, therefore, be controlled within a specified regulation figure. This article will discuss the Methods of Voltage Control in Transmission Lines by means of
Methods of Voltage Control in Transmission Lines Read More »
Power Flow through Transmission Line: So far the transmission line performance equation was presented in the form of voltage and current relationships between sending-and receiving-ends. Since loads are more often expressed in terms of real (watts/kW) and reactive (VARs/kVAR) power, it is convenient to deal with transmission line equations in the form of sending- and
Power Flow through Transmission Line Read More »
Equivalent Circuit of Long Transmission Line | π and T network: So far as the end conditions are concerned, the Equivalent Circuit of Long Transmission Line can be established in the form of a T- or π-network. The parameters of the equivalent network are easily obtained by comparing the performance equations of a π-network and
Equivalent Circuit of Long Transmission Line Read More »
Tuned Power Lines in Transmission: Equation (5.23) characterizes the performance of a Tuned Power Lines in long Transmission line. For an overhead line shunt conductance G is always negligible and it is sufficiently accurate to neglect line resistance R as well. With this approximation Hence Eq. (5.23) simplifies to Now if ωl√LC = nπ, n
Tuned Power Lines in Transmission Read More »
Ferranti Effect in Transmission Line: The effect of the line capacitance is to cause the no-load receiving-end voltage to be more than the sending-end voltage. The effect becomes more pronounced as the line length increases. This phenomenon is known as the Ferranti Effect in Transmission Line. A general explanation of this effect is advanced below:
Ferranti Effect in Transmission Line Read More »
Transmission Lines and Waveguides: As we know already that, γ is a complex number of Transmission Lines and Waveguides which can be expressed as The real part α is called the attenuation constant and the imaginary part β is called the phase constant. Now Vx can be written as where The instantaneous voltage vx(t) can
Transmission Lines and Waveguides Read More »
Long Transmission Line: For lines over 250 km, the fact that the parameters of a line are not lumped but distributed uniformly throughout its length, must be considered. Figure 5.10 shows one phase and the neutral return (of zero impedance) of a Long Transmission Line. Let dx be an elemental section of the line at
Long Transmission Line Read More »
Medium Transmission Line: For lines more than 100 km long, charging currents due to shunt admittance cannot be neglected. For lines in range 100 km to 250 km length, it is sufficiently accurate to lump all the line admittance at the receiving-end resulting in the equivalent diagram of Medium Transmission Line shown in Fig. 5.7.
Medium Transmission Line Read More »
Voltage Regulation of Transmission Line: Voltage Regulation of Transmission Line is defined as the rise in voltage at the receiving-end, expressed as percentage of full load voltage, when full load at a specified power factor is thrown off, i.e. where |VR0| = magnitude of no load receiving-end voltage |VRL| = magnitude of full load receiving-end
Voltage Regulation of Transmission Line Read More »
