| Abstract: |
| High penetration of Converter Interfaced Generations (CIGs) presents challenges in both microgrid (μGrid) circuit
and other system with CIG resources, such as wind farms and PV plants. Specifically, protection challenges are
mainly brought by the insufficient separation between fault and load currents, especially for μGrids in islanded
operation, and the short connection length in μGrids. In addition, CIG resources exhibit limited inertia and weak
coupling to any rotating machinery, which can result in large transients during disturbances. To address the above
challenges, this paper proposes a Dynamic State Estimation (DSE) based algorithm for protection and control of
systems with substantial CIG resources such as a μGrid. It requires a high-fidelity dynamic model and time domain
(sampled value) measurements. For μGrid circuit protection, the algorithm dependably and securely detects internal
faults by checking the consistency between the circuit model and available measurements. For CIG control, the
algorithm estimates the frequency at other parts of a μGrid using CIG local information only and then utilizes it to
provide supplementary feedback control. Simulation results prove that DSE based protection algorithm detects
internal faults faster, ignores external faults and has improved sensitivity towards high impedance faults when
compared to conventional protection methods. DSE based CIG control scheme also minimizes output oscillation
and transient during system disturbances. |
| Key words: Converter interfaced generation (CIG), Dynamic state estimation (DSE), μGrid protection |
| DOI：10.1186/s41601-018-0104-2 |
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| Fund: |
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