Traditionally Security Constrained Optimal Power Flow and VAr planning methods consider static security observing voltage profile and flow constraints under normal and post contingency conditions. Ideally, these formulations should be extended to consider dynamic security. This paper reports on a B.C. Hydro/CEPEL joint effort establishing a Dynamic Security Constrained OPF/VAr planning tool which considers simultaneously static constraints as well as voltage stability constraints. This paper covers the details of formulation and implementation of the tool together with the test results on a large scale North American utility system and a reduced Brazilian system.

The objective of contingency screening and ranking function is to shortlist a specified number of critical contingencies from a large list of credible contingencies and rank them according to their severity. This paper summarizes the work conducted as part of the EPRIA3.C. Hydro on-line voltage stability project in developing a Contingency Screening and Ranking (CS&R) module. The two methods of Reactive Support Index (RSI) and Iterative Filtering are derived in this paper and tested on the large scale systems of B.C. Hydro and another Major Unnamed Utility. The results obtained indicate that RSI on its own or in combination with the Iterative Filtering method can be used for CS&R depending on the acceptable level of misranking. The RSI method is a very fast and powerful CS&R method and is suggested for systems where some misclassification of contingencies can be tolerated. On the other hand, for systems where an exact list of critical contingencies is intended, then the Iterative Filtering method can be used for screening complemented with another method like RSI for ranking. The latter technique is being integrated in the EPRU6.C. Hydro On-line Voltage Stability tool.

The integration of power-to-heat (PtH) assets as grid oriented flexibilities can help balancing and stabilizing the increasingly strained distribution grid level. As a result of using demand side response, conventional grid reinforcements could be avoided/deferred in certain cases. Furthermore, decentralized renewables could be integrated more effectively. A multi-objective approach aims to improve the economics of the PtH asset using the flexibility in an optimized way. Whereas the grid oriented usage is chosen in certain times of grid restrictions due to fluctuating wind feed-in, system-/market oriented flexibility usage can be applied during the remaining time periods. Besides the technical solution of using different optimized flexibility dimensions, also the regulatory discussion for distribution grid operators is part of this paper indicating a need for actions to enable a suitable usage of demand side response potentials.

No abstract