Micro Grid
K. Mazlumi; A. Shabani
Abstract
In recent years, most of the loads and distributed generations are connected to the AC grid through the power electronic converters. Using the DC grid beside the AC grid can reduce the conversion stages and power losses. Protection of the DC grids is a challenging issue because of the new structures ...
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In recent years, most of the loads and distributed generations are connected to the AC grid through the power electronic converters. Using the DC grid beside the AC grid can reduce the conversion stages and power losses. Protection of the DC grids is a challenging issue because of the new structures of DC grids and fast transients of the DC faults. This paper studies the protection of the low voltage DC (LVDC) system in the presence of the photovoltaic (PV) and energy storage systems (ESS). An LVDC system consisting of a DC microgrid is considered and Different operating modes are analyzed. DC faults behavior and protection challenges are discussed for each mode through simulations employing MATLAB software. Finally, some methods are presented to solve the protection challenges. The results show that changing the protection arrangement of the system and choosing suitable control logics for the ESS and the PV prevent the unwanted outage of the loads and provide the possibility of the microgrid operation in islanded mode.
K. Mazlumi; M. Mohammad Gholiha1; R. Abbasi; F. Mazlumi
Volume 2, Issue 1 , June 2007, , Pages 32-39
Abstract
In this paper, a new method based on branch placement for the optimal positioning of Phasor Measurement Units (PMUs) in power systems is proposed. In this method, the PMUs are in type of single-channel and are installed at the beginning of the branches. Therefore, they are able to measure the bus voltages. ...
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In this paper, a new method based on branch placement for the optimal positioning of Phasor Measurement Units (PMUs) in power systems is proposed. In this method, the PMUs are in type of single-channel and are installed at the beginning of the branches. Therefore, they are able to measure the bus voltages. Also, the installation of the PMUs on the branches increases the security of observability in comparison to the bus placement method at the time of line or PMU outages. In this paper, the Genetic Algorithm (GA) method is used to solve the optimization problem. The proposed method is applied to IEEE 30-bus and 24-bus case study networks. In addition, the method is tested on a real 400 kV network in Iran.