Problems and Discussions

2 outubro 2012, 11:00 • Luis Marcelino Ferreira

Problems: Lab (by computer), Exam (by hand); sometimes a lab problem can be used as an exam problem, with a different approach

Discussion on approaches

Problem for one purely reactive line, two same specified-voltage buses, known active power injected: quest: reactive power and power factor

Review and Introduction to Newton's method

2 outubro 2012, 09:30 • Luis Marcelino Ferreira

Review of power flow equations as I=YV

Jacobi-Gauss: application, origin as from Ax=b for exact or approximate results

Linearity and nonlinearity, diagonal properties

Moving into Newton’s methods: what is the idea, what is expected, what is needed

Power flow equations in real format

Based on matrix analysis

Based on line parameters

Number of variables and number of equations

Which index should be given to the reference bus

Generator buses need only one eq per bus

Fundamentals of Newton’s

The importance of derivatives

Newton’s and Taylor’s

Interpretation

TE1 (cont) and TE2

1 outubro 2012, 08:00 • Luis Marcelino Ferreira

Review for TE1: results must be equal

Jacobi-Gauss vs solve()

TE2: discussion of problem, presentation of results

Again: Jacobi-Gauss vs solve()

Solution on a real parameter by trial and error (bissection, etc)

Ficha TE1

28 setembro 2012, 08:00 • Luis Marcelino Ferreira

Discussão do enunciado

Resolução em aritmética complexa

Discussão de resultados

Load and xf

27 setembro 2012, 11:00 • Luis Marcelino Ferreira

Active load and constant power

Passive load and constant admittance

Load as constant current

Load as a combination of loads

The concept of elasticity or sensitivity of power demand wrt voltage

P=KV^alpha

Nonpolynomial versus polynomial forms

Convenience of moving passive loads to diagonal elements of Y

Xfs as an important element of the networks

1, 2, 3, 4 winding xfs (per phase)

When, where and what for

Voltage regulating xf

Another form to make a PV bus

Steinmetz models

Models: RLC model, matrix model

Nonsymmetric admittance matrix for phase-shifter