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Effect of high capacitance at no load resulted from the long MV cabling?
Wiki User
∙ 14y ago
No load conditions on lines with large amounts of capacitance will cause the voltage to rise. This is similar to if a cap bank was installed at that location. I'm not sure how much capacitance is really involved at MV; I've never seen this to be a problem. Usually at these voltage levels, the step down Transformers have on load tap changers, and can adjust for this.
This is often a problem on EHV lines (230kV and above). On these lines, large inductors are used to counteract the capacitance of the line.
Wiki User
∙ 14y ago
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What is the effect if capacitance in transmission line is high?
higher phase shift lower impedance
What is the effect of capacitance at high frequencies?
A: Is the same as low frequency except it becomes a predominant factor.
Why the 3 phase of high voltage conductor or cable transposed?
3 phase cable is transposed to minimize the effect of leakage/capacitance current.
What is the stray capacitor?
Stray capacitance is undesired capacitance. Any electronic component (wires, resistors, etc.) has SOME capacitance; at high frequencies, this can become significant, becoming a problem for circuit design.
What is the effect of capacitance in high frequency circuits and how it is getting added?
First, capacitance is the resistance of something to a change in voltage. And capacitance exists anywhere there is a conductor that is insulated from another conductor. With that definition, anything has capacitance. And that's correct. It is also the key to understanding the capacitance in high frequency (radio frequency or RF) circuits. The fact that a circuit had conductive pathways and component leads and such means that there is a lot of little bits of capacitance distributed around the circuit. The capacitance is already there; it isn't "added" later as might be inferred. Normally, this bit of capacitance isn't a problem. But at higher and higher frequencies, it is. Remember that the higher the frequency of an AC signal, the better it goes through a given cap. So at higher and higher frequencies, the distributed capacitance in the circuit "shorts the signal to ground" and takes it out of the circuit. The RF is said to be coupled out of the circuit through the distributed capacitance in that circuit. The higher the frequency a given circuit is asked to deal with, the more signal will be lost to this effect. It's just that simple. Design considerations and proper component selection minimize the distributed capacitance in a circuit.
What is stray capacitance and how is different from ordinary capacitor?
Any two adjacent conductors can be considered a capacitor, although the capacitance will be small unless the conductors are close together for long. This (often unwanted) effect is termed "stray capacitance". Stray capacitance can allow signals to leak between otherwise isolated circuits (an effect called crosstalk), and it can be a limiting factor for proper functioning of circuits at high frequency. Stray capacitance is often encountered in amplifier circuits in the form of "feedthrough" capacitance that interconnects the input and output nodes (both defined relative to a common ground). It is often convenient for analytical purposes to replace this capacitance with a combination of one input-to-ground capacitance and one output-to-ground capacitance. (The original configuration - including the input-to-output capacitance - is often referred to as a pi-configuration.) Miller's theorem can be used to effect this replacement. Miller's theorem states that, if the gain ratio of two nodes is 1/K, then an impedance of Z connecting the two nodes can be replaced with a Z/(1-k) impedance between the first node and ground and a KZ/(K-1) impedance between the second node and ground. (Since impedance varies inversely with capacitance, the internode capacitance, C, will be seen to have been replaced by a capacitance of KC from input to ground and a capacitance of (K-1)C/K from output to ground.) When the input-to-output gain is very large, the equivalent input-to-ground impedance is very small while the output-to-ground impedance is essentially equal to the original (input-to-output) impedance.
Why ordinary diodes dont work properly At high frequencies?
Because of stray capacitance. At very high frequencies, the inter-electrode capacitance has a low enough impedance that the diode no longer cuts off when reverse-biased, there is still significant conduction via capacitive coupling. High-frequency diodes are constructed so as to minimize this capacitance.
What is meant by stray capacitance?
ANSWER Stray capacitance is the capacitance in a circuit not caused by capacitor components. There is a small capacitive effect, often on the order of a few picofarads, between leads of ICs, traces on a PCB, wires in a cable, the power and ground planes in a PCB, etc. In high-speed circuits, stray capacitance can be enough to completely change the operation of a circuit -- even to the point of keeping it from working as designed. Note that capacitor "components" can include PCB traces specifically designed to act as capacitors.
What does not limit current flow in a circuit - capacitance - high conductor resistance or longer conductor?
Of the three choices, capacitance does not limit current flow in an AC circuit.
Modern capacitors which have high capacitance in small size use a dielectric of?
mylar
Modern capacitors which have high capacitance in small size use a dielectric?
Ceramic
Is it possible to measure capacitance using only one 555 timer?
yes, it is possible to measure capacitance using only one 555 timer for it's monostable operation. When the output is high time is given by the equation t=1.1RC. From the output pulse measuring t(high) and then by measuring R we can calculate the capacitance.
