A Comprehensive Digital Protection Scheme for Low-inertia Microgrids Considering High Penetration of Renewables

Author(s):  
Gaber Magdy ◽  
Gaber Shabib ◽  
Adel A. Elbaset ◽  
Yasunori Mitani
2021 ◽  
Vol 9 ◽  
Author(s):  
Haitao Song ◽  
Li Yang ◽  
Shaoyu Chen ◽  
Wentao Huang ◽  
Nengling Tai

DC micro-energy system is an effective pattern to integrate high-penetration distribution generators. It has flexible operation modes and complicated fault characteristics, which requires protection with higher selectivity and sensitivity. This paper proposes a DC feeder protection method using the transient high-frequency currents. The fault direction and fault feeder are identified by comparing the amplitude of high-frequency currents of all ends. The amplitude ratio coefficient of DC voltages is introduced to detect the fault pole. The transient high-frequency components will not be affected by the communication delay and fault impedance. The protection scheme realizes the fast detection and clearance of different faults on feeders before the failure of the inverter-interfaced generators and loads, which ensure the reliable and safe operation of the non-fault zone. The model of a DC micro-energy system is established in MATLAB/Simulink and the efficiency of this method is verified by detailed simulations.


2020 ◽  
Vol 5 (2) ◽  
pp. 030-037
Author(s):  
Bernard Akindade Adaramola ◽  
Daniel Danjuma Chirpyen

Insulation of all electrical machinery is practically in the form of organic compounds that contain water as part of their make-up. Excessive temperature tends to dehydrate and oxidize the insulation and make it become brittle and disintegrate under vibration and shock. The insulation lifespan of turbo generators deteriorates slowly at low temperatures and more rapidly at high temperature. Economic factors, such as initial cost, replacement cost, obsolescence, and maintenance, are of prime importance when determining the years of useful service desired for the electrical insulation. Generator digital protection- fault diagnosis test was carried out to find out the cause of insulation breakdown on the turbo generator unit 411G3. The experimental procedure consists of an insulation resistance test, meggering (time-resistance absorption test), and pendulum over-speed test. A thorough investigation was conducted to identify all the stator bars that constituted the Red phase and other connections. Voltage drops on these stator bars were measured and values were used to detect ground faults which were rectified via an intelligent protection scheme.


2016 ◽  
Vol 57 ◽  
pp. 867-878 ◽  
Author(s):  
Sohrab Mirsaeidi ◽  
Dalila Mat Said ◽  
Mohd. Wazir Mustafa ◽  
Mohd. Hafiz Habibuddin ◽  
Kimia Ghaffari

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2350 ◽  
Author(s):  
Shazia Baloch ◽  
Saeed Zaman Jamali ◽  
Khawaja Khalid Mehmood ◽  
Syed Basit Ali Bukhari ◽  
Muhammad Saeed Uz Zaman ◽  
...  

To resolve the protection issues caused by high penetration of distributed energy resources, this paper proposes an efficient protection scheme for microgrids based on the autocorrelation of three-phase current envelopes. The proposed strategy uses a squaring and low-pass filtering approach for evaluating the envelope of the current signal. Then, the variance of the autocorrelation function is used to extract the hidden information of the distorted envelope to detect the fault signatures in the microgrid. Furthermore, the reactive power is used for determining the fault direction. The performance of the proposed protection scheme was verified on a standard medium-voltage microgrid by performing simulations in the MATLAB/Simulink environment (Version: R2017b). The proposed scheme was shown to be easy to implement and have good performance under looped and radial configuration for both grid-connected and islanded operation modes. The simulation results showed that the scheme could not only detect, locate, classify, and isolate various types of short-circuit faults effectively but also provide backup protection in case of primary protection failure.


2017 ◽  
Vol 10 (3) ◽  
pp. 18
Author(s):  
BHASKAR J. UDAY ◽  
KUMAR G. RAVI ◽  
TULASIRAM S.S. ◽  
◽  
◽  
...  

Sign in / Sign up

Export Citation Format

Share Document