دانلود رایگان مقاله انگلیسی سیستم های تولید برق توزیع شده و محافظت - IEEE 2017

ABSTRACT

Continuously expanding deployments of distributed power-generation systems (DPGSs) are transforming the conventional centralized power grid into a mixed distributed electrical network. The modern power grid requires flexible energy utilization but presents challenges in the case of a high penetration degree of renewable energy, among which wind and solar photovoltaics are typical sources. The integration level of the DPGS into the grid plays a critical role in developing sustainable and resilient power systems, especially with highly intermittent renewable energy resources. To address the challenging issues and, more importantly, to leverage the energy generation, stringent demands from both utility operators and consumers have been imposed on the DPGS. Furthermore, as the core of energy conversion, numerous power electronic converters employing advanced control techniques have been developed for the DPGS to consolidate the integration. In light of the above, this paper reviews the power-conversion and control technologies used for DPGSs. The impacts of the DPGS on the distributed grid are also examined, and more importantly, strategies for enhancing the connection and protection of the DPGS are discussed.

V. CONCLUSION

The technological developments in DPGSs were explored. It was revealed that the DPGS-based wind and PV technologies will be dominant in the future market and in future power systems. This paper first provided an overview of the power electronic technologies for wind and PV DPGSs, as the power electronics are the core of the energy conversion. More importantly, as the wind and PV energies are variable, uncertain, and nondispatchable, connecting these renewables to the distributed grid may cause instability. Therefore, stringent demands have been placed on the DPGS. These were also reviewed in this article, and control strategies were discussed. The investigation revealed that multiple control functions can be provided by the DPGS in order to improve the reliability, performance, and resilience of the entire grid. The constraints can be implemented by properly controlling the power electronic converters of the DPGS. This has become one important aspect for inverterbased DPGSs. However, it also introduces side effects. As the inverter-dominated DPGS does not have much physical inertia, the DPGS must be oversized in order to provide a satisfactory amount of fault currents, which increases the total cost. Nonetheless, DPGS protection is challenging. In this paper, the challenging issues regarding the DPGS were summarized, and the state-of-the-art protection techniques that can be applied to the DPGS were reviewed. Table 1 lists the advantages and disadvantages of the protection schemes discussed for the DPGS.

It can be concluded that the DPGS can increase the grid resilience, as it can operate in both the grid-connected mode and the islanded mode. In the case of an islanded DPGS, critical loads can be supplied upon demand when the main grid is absent. Additionally, the DPGS can help to restore the transmission system after disruptions; in return, the DGPS benefits from the transmission grid when it must be restored after failures. Communication and date processing technologies may be critical for ensuring the reliable, efficient, and resilient operation of distributed grids.