Unbalanced power flow algorithm in phase representation

[lthurner]

The current unbalanced power flow is based on symmetric components and a mixture of Newton-Raphson (positive sequence) and current iteration (zero/negative sequence) according to the paper "Improved Three-Phase Power-Flow Methods Using Sequence Components". This method works and gives accurate results that have been validated against commercial software.

However, there are two main drawbacks:

• current iteration usually does not scale well with system size
• symmetric component approach does not allow to model 1/2 phase load/transformer elements

That is why we want to switch to Newton-Raphson solver in phase representation.

The admittance matrices are already validated in positive/negative/zero sequence components, so it makes sense to keep them this way. They could be transformed to Ya/Yb/Yc matrices and then solved with a Newton-Raphson. Does anyone know of a good description for an unbalanced Newton-Raphson in literature?

[lthurner]

This seems like a good source: https://repository.tudelft.nl/islandora/object/uuid%3A505450d0-2cc0-46fc-bb7d-2f9578645e25