Power Swing Detection Research Articles

Improving power swing detection in the presence of doubly-fed induction generator wind farms based on setting adaptation

This article proposes a new approach to improve the security of transmission line protection by correctly detecting power swing when large-scale doubly-fed induction generator wind farms (DFIGWF) exist in the proximity of the relay. In the presence of large-scale DFIGWFs, following large disturbances, power swing may probably cause the distance protection to malfunction. This issue can also lead to widespread transmission line outage and cause instability in the power system. Therefore, a new approach is proposed to solve the challenge by adapting the power swing blocking (PSB) function in the distance protection relays and utilizing the dominant power system oscillation modes. Thus, related calculations are performed in a central module remotely connected to intelligent electronic devices (IEDs) for distance protection and stabilized against power swing. The calculation to adjust the PSB setting of the IEDs in the central module is based on the oscillation modes of the power system and the rate of change of impedance, which is influenced by the penetration rate of the DFIGWFs. Simulation studies have been done on two test systems and the results reveal that the proposed scheme significantly improves the security of distance protection against power swing under different DFIGWF intrusion conditions.

A non-PMU-based WAN protection scheme for swing detection and stability enhancement in power systems

This paper presents a scheme for power swing detection and stability assessment for multi-machine power systems in addition to a brief survey on that topic. The scheme adopts smart grid perception. It is an asynchronous scheme that uses the rate of change of the angle of the generator bus voltage instead of synchronously estimating the absolute rotor angle value for stability assessment. Therefore, it does not require phasor measurement units (PMUs). Instead, it uses commercially available intelligent electronic devices (IEDs). It introduces a new application of the multicast Generic Object Oriented Substation Event (GOOSE) protocol or its routable version (R-GOOSE) to reflect the disturbance in the power grid on the transmission pattern of data packets over the grid data network. In this scheme, the angle change information is transmitted in the form of GOOSE packets simultaneously from the IEDs that readily measure the angles of the affected generators. On the other hand, the detecting device identifies the stability status of each affected generator. The proposed scheme is validated by simulating disturbances on the IEEE 39-bus system. The results show that the scheme can discriminate between stable and unstable swings. In addition, the loss of synchronism of the unstable generator is predicted ahead of its occurrence by enough time to take an appropriate action.

A new power swing detection method in power systems with large‐scale wind farms based on modified empirical‐mode decomposition method

AbstractHigh energy consumption around the world and concerns over climate change and high greenhouse gas emissions have led to a significant increase in using renewable energy resources, particularly wind power plants. In spite of using small wind farms in distribution networks as distributed generation, the interest in employing large‐scale wind farms in transmission levels has grown significantly in recent years. The presence of large‐scale wind farms with a synchronous generator to supply the energy demand can affect the power swing parameters. These effects are in a way that can mislead power swing detection methods and cause undesirable tripping of transmission line due to mal‐operation of distance relay against power swing . Therefore, in this paper, a method has been presented based on modified empirical mode decomposition (EMD) method to differentiate fault from power swing in the networks connected to the large‐scale wind farms. The results prove the efficiency of the presented method in detecting the power swing in large‐scale wind farm networks. Finally, a comparison is conducted between the proposed method and similar methods which proves the efficiency and superiority of the proposed method in terms of noise tolerance, detection fault detection speed, and multi‐mode power swing detection compared to the current methods.

An overview of power swing detection methods in distance relays and the factors involved

An overview of power swing detection methods in distance relays and the factors involved

Power Swing Detection in Parallel Transmission Lines Connected to Wind Farms Employing del2sg Method

Power Swing Detection in Parallel Transmission Lines Connected to Wind Farms Employing del2sg Method

Power Swing and Fault Detection in the Presence of Wind Farms Using Generator Speed Zero-Crossing Moment

Nowadays, due to the entry of wind power plants into the power systems, which causes changes in the network parameters, power swing detection has become more important. Changes in the wind speed and noncontinuity of the wind power plants lead to changes in the power swing characteristic. Therefore, the impedance seen by the distance relay is changed, and so the maloperation of the relay during the stable power swing may occur. This paper proposes a new method to detect power fluctuations based on the synchronous generator speed while it is independent of the network parameters. Based on the proposed method, the generator speed at any moment does not pass through zero during the stable power swing. In contrast, it passes through zero by occurring fault types with high and low fault resistance, fault types during power swing, and an unstable power swing. Therefore, the method prevents maloperation of distance protection. It is worth noting that the proposed method is applicable for distance protection in any power system with and without wind power plants, such as in the distance protection of compensated transmission lines. The obtained results indicate that the proposed method detects power fluctuations in a short time.

Synchrophasor Assisted Power Swing Detection Scheme for Wind Integrated Transmission Network

Integration of wind-based renewable energy sources into long Extra High Voltage/Ultra High Voltage uncompensated/compensated power transmission network poses significant problems in terms of proper detection of power swings and effective discrimination between symmetrical faults and power swing situations. As the existing protection strategies are unable to detect the said circumstances, a novel technique, based on the difference between sending end and receiving end positive sequence currents angles of the transmission line, is proposed in this paper. The required data is collected with the help of Phasor Measurement Units placed on both sides of the line. The scheme results in effective discrimination between distinct faults and circumstances of asymmetrical/symmetrical power swing and achieves satisfactory outcome during current transformer saturation condition. The proposed algorithm is evaluated on the wind-integrated IEEE-9 bus system by producing power swings, various cases of faults, and faults during power swings. Validation of the suggested technique was carried out by the execution of hardware-in-loop simulation on a Real-Time Digital Simulator. The achieved outcomes disclose higher sensitivity and better discriminating ability of the presented technique in comparison with those of numerous prevailing methods.

Analysis of wind farm penetration on power swing detection in distance relays

Distance protection plays an essential role in the protection of sub-transmission and transmission lines in power systems. However, power swings have occasionally led to the mal-operation of this type of protection. A significant number of large disturbances, such as blackouts, start with power swings. Thus, improving the circumstances leading to this disruptive phenomenon becomes a great priority. Nowadays, the wind power share of worldwide electricity generation and the use of wind farms have increased. As a result, to predict future events, it is necessary to assess the network in the presence of these renewable sources. In this paper, the effects of the wind resources penetration on power swing have been evaluated. Simulations and analyses have been performed in PSCAD/EMTDC and MATLAB environments, respectively. To provide a comprehensive analysis, maximum power passing through the transmission line and power swing frequency have been utilised as criteria. The results show that wind farms presented acceptable behaviour in the presence of power swing and instability. Therefore, in view point of a power swing, induction generator based wind power plants, compared to synchronous generators, led to better overall conditions. Finally, the effect of fixed and variable speed wind turbines on power swing is compared.

Modeling and Implementation of Power Swing Detection and Out-of-Step Protection

Modeling and Implementation of Power Swing Detection and Out-of-Step Protection

Rotating negative-sequence phasors for blocking and unblocking the distance protection during power swings

When power swings occur in transmission lines, the apparent impedance seen by the distance relay can shift toward the protection zone. This may result in unwanted trips in the protection system. This study proposes novel algorithms for detecting power swings and performing power swing blocking (ANSI 68) and unblocking through fault detection during power swings. The algorithms are free of settings and apply mathematical tools employed in commercial relays, such as the Fourier filter and symmetrical components. They are based on an analytical solution originally proposed in this study that demonstrates that negative-sequence phasors present a rotating behavior during a power swing, which can be used as a fundamental principle for power swing detection. The IEEE 9-bus electrical system is implemented in Matlab/Simulink to validate the proposed algorithms. The results show that the proposed algorithms effectively achieve blocking through power swing detection and achieve unblocking through fault detection. The latter function is shown to perform better than two algorithms available in the literature.

Detection of power swing and blocking the distance relay using the variance calculation of the current sampled data

Detection of power swing and blocking the distance relay using the variance calculation of the current sampled data

Power Swing Blocking Algorithm based on Real and Reactive Power Transient Stability

Power swing due to the disturbance in the power system is a cause of the untrue operation of protective elements. Previously, many blackouts have been perceived and recorded due to reactive power mismatch problems, active power mismatch problems, and system venerability. The power system stability is usually disturbed due to the sudden loss of transmission lines, generators, and transformers. The present work proposes the concept of apparent power transient stability due to the transient disturbance. By considering that concept, we propose a power swing blocking algorithm to prevent mal-operation of distance relay. The proposed algorithm uses the relative frequency between the sending end bus and system standard frequency with simultaneous measurement of voltage decay of the transmission line. We have implemented the proposed algorithm on a single machine infinite system (SMIB) and the IEEE-9 bus system to compare the power swing detection and blocking performance with mho type out of step relay in different power swing conditions. In the end, results show the accurate performance, simplicity, reliability, and correct co-ordination of the proposed relay with distance relay, which ultimately solved the issue of mal-operation of zone-3 distance relay during complex power swing conditions.

Comprehensive power swing detection by current signal modeling and prediction using the GMDH method

Power swing is an undesirable variation in power flow. This can be caused by large disturbances in demand load, switching, disconnection or reclosing lines. This phenomenon may enter the zones of distance relays and cause relay malfunction leading to the disconnection of healthy lines and undermining network reliability. Accordingly, this paper presents a new power swing detection method based on the prediction of current signal with a GMDH (Group Method of Data Handling) artificial neural network. The main advantage of the proposed method over its counterparts is the immunity to noise effect in signals. In addition, the proposed method can detect stable, unstable, and multi-mode power swings and is capable of distinguishing them from the variety of permanent faults occurring simultaneously. The method is tested for different types of power swings and simultaneous faults using DIgSILENT and MATLAB, and compared with some latest power swing detection methods. The results demonstrate the superiority of the proposed method in terms of response time, the ability to detect power swings of different varieties, and the ability to detect different faults that may occur simultaneously with power swings.

Impact of Inverter Based Resources on System Protection

Inverter-based resources (IBRs) exhibit different short-circuit characteristics compared to traditional synchronous generators (SGs). Hence, increased uptake of IBRs in the power system is expected to impact the performance of traditional protective relay schemes—set under the assumption of a SG-dominated power system. Protection engineers need to study these challenges and develop remedial solutions ensuring the effectiveness of system protection under higher levels of IBRs. To address this need, this paper studies the impact of IBRs on a variety of protective relay schemes including line distance protection, memory-polarized zero sequence directional protective relay element, negative sequence quantities-based protection, line current differential protection, phase comparison protection, rate-of-change-of-frequency, and power swing detection. For each protection function, potential misoperation scenarios are identified, and recommendations are provided to address the misoperation issue. The objective is to provide an improved understanding of the way IBRs may negatively impact the performance of traditional protection schemes as a first step towards developing future remedial solutions ensuring effective protection under high share of IBRs.

A New Model of Numerical MHO Distance Relay Associated with Power Swing Detector

In conventional transmission line protection, a distance relay is used to provide the primary as well as backup protection. The voltage and current phasors measurement needed by the distance relay for determining the impedance may be affected by the power disturbances such as power swing. Consequently, this power swing may cause mal-operation of Zone three distance relays which in turn may affect on the reliability of the whole protective scheme. Many power swing blocking functions (PSB) have been developed to mitigate these effects. In this paper, a new model of Mho distance relay with dual-quadrilateral power swing detection characteristic has been developed and implemented first in PC using LabVIEW, then tested using Power System Simulink Model under different faults and power swing conditions. Finally, the relay prototype has been realized using acquisition card NI USB-6009, which acquires real-time signals of the currents and the voltages, processes them digitally and outputs tripping or blocking signal to the circuit breaker. The obtained results show that the relay provides good discrimination between a fault and power swing condition.

Detection of power swing and prevention of mal‐operation of distance relay using compressed sensing theory

Power system protection has become an essential challenge with the development of the power system. This study presents a new method in detecting a power swing based on compressed sensing. The proposed method is tested on the IEEE 39-bus network using MATLAB and DIgSILENT software. The simulation results show that the presented method is able to detect and differentiate between different types of power system conditions: stable, unstable, and multi-mode power swings. In addition, this method has a high speed in detecting the simultaneous fault with the power swing phenomenon. Moreover, the proposed method is capable of operating correctly despite noise signal in the system. This study has proven that the suggested method outperforms most of the existing methods as shown in the comparison section.

A Fast Fourier Transform-Based Method for Power Swing Detection and Distance Relay Malfunction Prevention

Fourier transform has abundant applications in the field of power systems. One of the chief uses of this technique is differentiating between power swings and the faults occurring simultaneously with these swings in the power system. Despite many efforts to use Fourier transform for this purpose, the available methods have significant restrictions that affect their applicability. This paper introduces a new method based on Fourier transform for detecting power swings and various types of simultaneous faults that occur during the power swings. The strength of the proposed method in comparison with currently used schemes is the capability of detecting the unstable and multi-mode power swings and also detection of high-impedance faults. Since the performance of the proposed method depends on defining a threshold value, this paper also provides a quick and simple way to determine this threshold value for various power networks. DIgSILENT and MATLAB softwares have been used to test the proposed method on the standard IEEE 39-bus test system for different scenarios of power swing and simultaneous fault conditions.

A Study on the Out-of-Step Detection Algorithm Using Time Variation of Complex Power-Part II: Out-of-Step Detection Algorithm and Simulation Results

One of the established unstable power swing (out-of-step) detection algorithms in micro grid/smart grid power systems uses a trajectory of apparent impedance in the R-X plane. However, this algorithm is not suitable for fast out-of-step conditions and it is hard to detect out-of-step conditions exactly. Another algorithm for out-of-step detection is using phasor measurement units (PMUs). However, PMUs need extra equipment. This paper presents the out-of-step detection algorithm using the trajectory of complex power. The trajectory of complex power and generator mechanical power is used to identify out-of-step conditions. A second order low pass digital filter is used to extract the generator mechanical power from the complex power. Variations of complex power are used to identify equilibrium points between stable and unstable conditions. The proposed out-of-step algorithm is based on the modification of assessment of a transient stability using equal area criterion (EAC). The proposed out-of-step algorithm is verified and tested by using alternative transient program/electromagnetic transient program (ATP/EMTP) MODELS.

Modern Techniques for Power Swing Detection and Classification - A Review

Modern Techniques for Power Swing Detection and Classification - A Review

Power swing detection and blocking of the third zone of distance relays by the combined use of empirical‐mode decomposition and Hilbert transform

This study aimed to develop a new method for detecting power swings and faults that may occur during these swings based on the combined use of empirical-mode decomposition and Hilbert transform. Power swings including line disconnection, fault occurrence, large sudden changes in the demand load, and reclosing, can cause a distance relay to malfunction and sever healthy lines from the network. Therefore, power swings and their simultaneous faults can pose a major challenge to protect the power systems. The proposed method in this study was tested on the standard IEEE 39-bus network for different power swing and fault states. It was also implemented on a distance relay manufactured by Vebko-Amirkabir Co. The evaluations show that the proposed method completely outperforms the conventional industrial method and other available methods in the literature. Since the proper functioning of this method depends on the choice of a threshold value, the current study also provides a simple and practical way to determine this threshold.