@article {6564,
	title = {Hybrid Passive-Overcurrent Relay for Detection of Fault in Low- Voltage DC Grids },
	journal = {IEEE Transactions on Smart Grid},
	volume = {8},
	year = {2015},
	pages = {1129 - 1138},
	abstract = {<p>Detection of high-resistance faults on meshed low-voltage dc grids poses a challenge, as such faults have very low fault current magnitudes. This paper proposes a hybrid passive-overcurrent relay to overcome this problem. The proposed relay consists of one current and one voltage transducer, as well as two passive elements: 1) an inductor; and 2) a capacitor. For bolted and relatively low-resistance faults, the relay uses a simple overcurrent function to detect the resultant high fault current magnitudes within 2 ms. On the other hand, for relatively high-resistance faults, a real-time discrete wavelet transform is used to detect the voltage transients generated by the relay passive elements in less than 5 ms. Furthermore, the proposed relay is inherently capable of identifying the type of fault. The proposed approach relies on local-bus measurements to detect and classify various types of faults with resistance up to 200 ohms. Analytical modeling proves that the proposed approach is system independent. Testing the hybrid passive-overcurrent relay on a {\textpm}750 V meshed TN-S dc grid reveals that the proposed relay is fast, sensitive, and selective under various conditions.</p>},
	url = {http://ieeexplore.ieee.org/abstract/document/7283661/},
	author = {K. A. Saleh and Ali Hooshyar and E. El-Saadany}
}
