Shortcircuits

25 outubro 2012, 11:00 • Luis Marcelino Ferreira

What is meant by a shortcircuit

Nonsimultaneous sc

Effects of sh and the importance of sc analysis

How to model the network

Choice of an appropriate linear network

Review of basic linear circuits: concepts of admittance and impedance

1-port, 2-port, multiport networks

Thevenin equivalent

Superposition principle

Modelling of a sc using two opposite voltage sources

Overall summary

Two power flow problems

23 outubro 2012, 11:00 • Luis Marcelino Ferreira

A hypothetical 5-node system with a pf solution

How to compute power flow in a given line

Consider a new two-port element and a procedure to obtain the nodal impedance matrix

Computation of Y12

The opposite problem: given a phase shifter what are possible results for a laboratory testing

How to consider the insertion of the element in the 5-node system between node 2 and node 4

Lab problem #2: how to make an equivalent 2-node system

When could one have to consider a 3-node system

Can one generator and two loads be simplified into a system of one generator and one load? When? Example

Sensitivities, radial networks, probabilistic power flow

23 outubro 2012, 09:30 • Luis Marcelino Ferreira

Review of loss sensitivities

Example of a situation in which one could compute sensitivity of losses wrt power injections

Radial networks and distribution system

Why a radial structure for networks

Trees and the relationship parent-child

Power flow for distribution networks

Upward sweeping for currents

Downward sweeping for voltages

Convergence criterion

Loads are uncertain: fuzzy vs probabilistic

Radially currents are random variables and what adds up are random variables

Types of random variables for loads

Mean values add up, as E(.) is a linear operator

std(.) is not linear

Near the top (of the tree), the current’s distribution is more concentrated near the mean value: smaller std

For security reasons the system is planned for values far from mean values (2 std’s); numerical values for currents in a node do not add up

Probabilistic analysis if the network is meshed: an introduction to Monte Carlo

What are the final results of a probabilistic analysis

TE4

22 outubro 2012, 08:00 • Luis Marcelino Ferreira

Revisão de TE3

Discussão de TE4

Apresentação da estrutura de resolução

Resultados numéricos

TE3

19 outubro 2012, 08:00 • Luis Marcelino Ferreira

Discussão do problema

Apresentação da estrutura de resolução

Resultados numéricos