scholarly journals A New Passive Islanding Detection Solution Based on Accumulated Phase Angle Drift

2018 ◽  
Vol 8 (8) ◽  
pp. 1340 ◽  
Author(s):  
Jinlei Xing ◽  
Longhua Mu
Keyword(s):  
Phase Angle ◽  
Low Cost ◽  
Rate Of Change ◽  
Islanding Detection ◽  
Physical Systems ◽  
Power Cycle ◽  
Three Phase ◽  
Voltage Phase ◽  
System Frequency ◽  
Vector Shift

The existing passive methods for islanding detection are mainly based on the detection of voltage and frequency deviation after islanding, using protections such as voltage vector shift (VVS) and rate of change of frequency (ROCOF). Although there are reported issues with these passive methods such as inherent non-detection zones and nuisance trips, utilities prefer the passive methods due to the low cost and simplicity of deployment. In this paper, one composite passive islanding detection method is presented. It tracks the voltage phase angle, the system frequency, and ROCOF every power cycle. If three phase voltage vectors shift in the same direction and the rotated angle values are balanced, the calculation of the accumulated phase angle drift (PAD) will be initiated. This calculation continues until the ROCOF measurement is below the ROCOF setting threshold. If the accumulated phase angle drift reaches the set angle threshold, the condition for islanding is claimed. The performance of this composite method is verified under different scenarios based on Matlab Simscape multidomain physical systems and practical waveforms recorded from sites. Although there are still non-detection zones, this composite PAD solution has better sensitivity than existing VVS and ROCOF methods and is stable under external system faults.

scholarly journals Islanding Detection Using a Micro-Synchrophasor for Distribution Systems with Distributed Generation

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5180
Author(s):  
Karthikeyan Subramanian ◽  
Ashok Kumar Loganathan
Keyword(s):  
Distributed Generation ◽  
Phase Angle ◽  
Distribution Systems ◽  
Detection Algorithm ◽  
Rate Of Change ◽  
Islanding Detection ◽  
Phase Angle Difference ◽  
Angle Difference ◽  
Voltage Phase ◽  
Islanded Grid

Distributed Generation (DG) has changed the power generation system to small-scale instead of large-scale generation. The demanding issue with the interconnection of DG is the detection of unintended islanding in a network. Several methods proposed in the literature show drawbacks such as high non-detection zones (NDZ) and higher tripping time. In this paper, the IEEE 13 bus distribution network with DGs like wind and solar power plants is integrated at two buses. Islanding is detected by utilizing data from a micro-synchrophasor located at the distribution grid and the DG. The micro-synchrophasor-based unintended islanding detection algorithm is based on parameters such as voltage, rate of change of voltage, frequency, rate of change of frequency, voltage phase angle difference and the rate of change of the voltage phase angle difference between the utility and the islanded grid. The proposed islanding detection algorithm discriminates between islanding and non-islanding conditions and is highly efficient under zero power mismatch conditions. The proposed method has null NDZ and satisfies the IEEE 1547 standard for DG tripping time. The effectiveness of the proposed IDM was verified when there are multiple DGs in the islanded grid. Also, the proposed method does not require additional hardware as it can be incorporated in digital relays with synchrophasor functionality.

Identificación de polaridad de los devanados en un motor trifásico de 6 terminales

2019 ◽  
pp. 13-19
Author(s):  
José Luis Viramontes-Reyna ◽  
Josafat Moreno-Silva ◽  
José Guadalupe Montelongo-Sierra ◽  
Erasmo Velazquez-Leyva
Keyword(s):  
Low Cost ◽  
Voltage Reference ◽  
Three Phase ◽  
Voltage Phase ◽  
The Law ◽  
And Control

This document presents the results obtained from the application of the law of Lens to correctly identify the polarity of the windings in a three-phase motor with 6 exposed terminals, when the corresponding labeling is not in any situation; Prior to identifying the polarity, it should be considered to have the pairs of the three windings located. For the polarity, it is proposed to feed with a voltage of 12 Vrms to one of the windings, which are identified randomly as W1 and W2, where W1 is connected to the voltage phase of 12 Vrms of the signal and W2 to the voltage reference to 0V; by means of voltage induction and considering the law of Lens, the remaining 4 terminals can be identified and labeled as V1, V2, U1 and U2. For this process a microcontroller and control elements with low cost are used.

Sequence Component-Based Improved Passive Islanding Detection Method for Distribution System with Distributed Generations

2019 ◽  
Vol 20 (2) ◽  
Author(s):  
Bhatraj Anudeep ◽  
Paresh Kumar Nayak
Keyword(s):  
Distributed Generation ◽  
Distribution System ◽  
Low Cost ◽  
Rate Of Change ◽  
Islanding Detection ◽  
Detection Scheme ◽  
Small Power ◽  
Distributed Generations ◽  
Sequence Components ◽  
Detection Schemes

Abstract In distributed generation (DG) systems, the rate of change of voltage and the rate of change of frequency are the two most common and widely used simple and low-cost passive islanding detection schemes. Unfortunately, these passive islanding detection schemes find limitation for detecting the islandings that cause very small power imbalance. In this paper, an improved passive islanding detection scheme is proposed by using the two newly derived indices from the sequence components of the current signal with the conventional voltage and frequency parameters. The performance of the proposed scheme is tested for numerous islanding and non-islanding cases generated on IEEE Std 399–1997 and IEC microgrid model distribution system integrated with both inverter-interfaced and synchronous DGs through PSCAD/EMTDC. The obtained results confirm the effectiveness of the proposed scheme.

scholarly journals Improved Three-Phase AFD Islanding Detection Based on Digital Control and Non-Detection Zone Elimination

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2421
Author(s):  
Xinxin Zheng ◽  
Rui Zhang ◽  
Xi Chen ◽  
Nong Sun
Keyword(s):  
Control System ◽  
Phase Angle ◽  
Digital Control ◽  
Detection Method ◽  
Frequency Drift ◽  
Phase System ◽  
Islanding Detection ◽  
Detection Zone ◽  
Three Phase ◽  
Three Phase Inverter

This paper proposes an improved active frequency drift (AFD) islanding detection method of a three-phase inverter. Different than the existing single-phase AFD method, in the three-phase system, the disturbance is added to the phase angle, which takes part in coordinate transformation calculations. Thus, the frequency drift of the three-phase reference current can be realized by the disturbance of the phase angle. It is unnecessary to add frequency drift to each phase respectively with the proposed method, which can simplify the control system. Furthermore, the non-detection zone can be eliminated by updating certain parameters; therefore, the detection method is sensitive. In this paper, the application of the proposed method in a digital control system is discussed in detail. The non-detection zone is analyzed, and an elimination method is proposed. Finally, the simulation and experimental results are given to verify the theoretical analysis.

Preventing third zone maloperation during power system stressed conditions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kasimala Venkatanagaraju ◽  
Monalisa Biswal
Keyword(s):  
New England ◽  
Average Rate ◽  
Test System ◽  
Rate Of Change ◽  
Distance Relay ◽  
Power Cycle ◽  
Power Swing ◽  
Protective Relay ◽  
Three Phase ◽  
Nuisance Tripping

Abstract The back-up third zone unit of distance relay may issue nuisance tripping command during different system critical events like power swing, voltage stress/instability and load encroachment. Since, such events are system symmetry phenomenon, the protection unit will not always able to discern them from three phase (symmetrical) fault in the distance relay third-zone region. The conventional relay algorithm fails to make a proper decision and results in unwanted tripping. This may further lead to system blackout. To mitigate this problem, a new approach based on the average rate of change of current (ARCC) is proposed. The method will work in integration with the conventional distance relay impedance setting algorithm to provide better results. The main advantage of the method is that it considers only local end current information. Within one power cycle, an accurate decision can be taken by the protective relay. The proposed method is validated considering IEEE 39-bus New England test system and the Indian regional power grid model modeled using EMTDC/PSCAD software. The simulation results for various critical cases and comparative analysis with existing methods shows effectiveness of the proposed method.

scholarly journals Evaluation of Passive Islanding Detection Methods for Line to Ground Unsymmetrical Fault in Three Phase Microgrid Systems: Microgrid Islanding Detection Method

2021 ◽  
Vol 11 (5) ◽  
pp. 7591-7597
Author(s):  
L. Bangar Raju ◽  
K. Subba Rao
Keyword(s):  
Phase Angle ◽  
Power Distribution ◽  
Distribution Systems ◽  
Detection Method ◽  
Rate Of Change ◽  
Detection Methods ◽  
Islanding Detection ◽  
Detection Zone ◽  
Local Methods ◽  
Nuisance Tripping

Distributed Generators (DGs) are incorporated in the power distribution systems to develop green energies in microgrids. Islanding is a challenging task in a microgrid. Different types of islanding methods, e.g. local and remote methods, have been developed for handling this task, with local methods being easier to implement, while remote methods are communication-based and costly. The local methods are classified as passive, active, and hybrid, out of which the passive methods are more simple and economical. In this paper, a passive islanding detection method is proposed to detect single line to ground fault. This fault is considered to represent the 60 to 70% of the total un-intentional faults of this category. The available passive methods cannot detect islanding at lower power mismatches as the variations in voltage and frequency fall within thresholding values. In this method, the voltage signals are first retrieved at the targeted DG output and then the phase angle is estimated. Finally, the phase angle is differentiated to get Rate Of Change Of Voltage Phase Angle (ROCOVPA) to detect islanding, and then it is compared with the Rate Of Change Of Frequency (ROCOF) at zero percent power mismatch. Simulation results depict that the ROCOVPA is more effective than ROCOF. The proposed method not only reduces detection time and Non-Detection Zone (NDZ) but is also stable during non-islanding cases like load connection and disconnection to avoid nuisance tripping.

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