Sumários
Review, DCPF, and summary
11 outubro 2012, 11:00 • Luis Marcelino Ferreira
Review of PV buses
PVQ bus, P bus
Review of procedure
Review of FDPF
Where to get the idea of sepation of P,teta and Q, V
Direct current power flow, DCPF
Analogy with a resistive circuit and nodal current injections
The same B’, P injections; unknowns are teta
The ubiquitous role of a slack generator
Which power flow method is most used?
Why? Planning problems vs operations problems
A question of linearized and assume linearity pf vs linearized and successive linearizations
Summary of power flow problems and power flow methods
Neutra
9 outubro 2012, 11:00 • Luis Marcelino Ferreira
Não houve esta aula -- é a aula que fica vazia de 3 em 3 semanas
Newton, Quasi-Newton, decoupling, FDPF
9 outubro 2012, 09:30 • Luis Marcelino Ferreira
Complex pf eqs: Jacobi, Gauss, Seidel; no. of eqs
Real pf eqs: rectangular coordinates: Newton; no. of eqs
Real pf eqs: polar coordinates: Newton; no. of eqs
Experimentation with Newton Lab TE3: N and J zeroed; diagdiagN and diagdiagL; other experiments such as BB and diagdiagBB
Most simplified Newton (which works) vs Gauss: how they compare
Advantages and disadvantages of decoupling
Decoupling and not updating: keep Jacobian approximate and constant
Fast decoupling, Stott, approximation made in order to obtain B’ and B”
Why despite different Jacobians the solution remains exactly the same one
How to test convergence properties for Lab exercise: further loading; network weakening
Observe number of iterations, Jacobian eigenvalues
PV bus: assumption may not hold; how to proceed
TE1 (cont) and TE2
8 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)
Powerflow eqs in real format and Newton's
4 outubro 2012, 11:00 • Luis Marcelino Ferreira
Powerflow eqs in real format
Based on separation of the matrix form of I=YV
Vectors P, Q; Matrices G and B
Polar form: V, theta
Rectangular form: Re(V), Imag(V)
Advantages and disadvantages of polar vs rectangular
Can Newton’s be used in rectangular form?
PV buses: how to handle them
Power flow without a I=YB matrix base: nodal power eqs
Newton’s method and the role of derivatives
Computation of dPi/dthetaj, dPi/dVj, dQi/dthetaj and dQi/dVj
Use (.)/dVj/Vj instead: historical advantages
Assembling J
inv(J) is merely symbolic: do not use it for Newton’s, not even in Matlab
Matrix factorization: review basics
Numerical example of a J