Sumários
Newton, Quasi-Newton, decoupling, FDPF
12 outubro 2017, 11:00 • 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
Powerflow eqs in real format and Newton's
10 outubro 2017, 09:30 • 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