Research On Electrical Power System Control Partitioning Based On Phase Measurement

The development of the Power Internet and the emergence of large-scale joint power grid makes the grid stability problems be increasingly prominent. So the research on the system’s security and stable operation of power grid hierarchical control methods are particularly important.In this thesis, the main job could be shown as follows:(1) Two kinds of phase measurement methods including zero-crossing detection method and the discrete Fourier transform method are compared in this paper, therefore, zero-crossing detection method is chosen to be applied to the Phase Measure Unit designing.(2) Phase Measure Unit’s designing is divided into hardware and software designing, GPS and AT89LV52 microcontroller with internal counter are used to cooperate with each other to establish a high-precision real-time clock system for high-precision measurement of the voltage phase angle foundation. The GPS clocks are taken for the whole network’s synchronization, the grid voltage zero crossing moments are selected as the exact time stamps, then the time stamps are uploaded to the PC by the communication portion, ultimately, grid voltage phase angles are calculated.(3) Partition methods are studied through the obtained grid voltage and current phase angle, therefore, fuzzy clustering based on fuzzy equivalence relation and fuzzy clustering based on the objective function of these two kinds of voltage partition method are proposed. On one hand, Both methods are based on the source of reactive power control thought, PQ nodes are objects to be classified, on the other hand, each of the control actions of reactive power source are considered to be its characteristic index of the object, ultimately, the index formed by such feature data are cluster analyzed to achieve the division of PQ nodes.Based on the different response process between PV and PQ nodes, all nodes are divided into two domains of thought, then PV nodes’ partitioning realized.(4) New England 39-bus system is taken as an example, at the same time, the method proposed in this paper is digital simulated. The results showed that both methods mentioned here are reasonable and effective, and fuzzy clustering method based on objective function has a simple algorithm, convergence to good effect and many other advantages.