Power Control Centers Research Articles

A Review on Automatic Control in Power System

Power systems are the foundation of contemporary society, providing energy for businesses, homes, and technological advancements. Precision, adaptability, and reliability are essential for these systems' complicated network of parts to satisfy the rising needs of our energy-hungry society. In this review paper, the vital function of automatic control systems in power systems is examined, along with how very important they are to maintaining stability, dependability, and sustainability. In the opening section of the essay, the basic building blocks of power systems generators, transformers, transmission lines, distribution networks, substations, and control centers are explained. The complex interactions between these components highlight how dynamic and complicated power systems are, posing several problems that need for clever control measures. Different control methods are examined, from conventional ones like proportional-integral-derivative (PID) control to cutting-edge ones like model predictive control and adaptive control methods. Each approach is evaluated for its unique benefits and innate weaknesses, providing a thorough grasp of its applicability in various operational settings. The command and control of the current power grid depends on Wide-Area Monitoring and Control (WAMS) systems, which are made possible by synchrophasor technology and reliable communication networks. Grid operators have the tools they need to maintain stability and respond quickly to emergencies thanks to their capacity to offer real-time data and improve situational awareness.

Application of GNS3 to Study the Security of Data Exchange between Power Electronic Devices and Control Center

This paper proposes the use of the GNS3 IP network modeling platform to study/verify whether the exchanged information between power electronic devices and a control center (Monitoring and Control Centre) is secure. For the purpose of this work, a power distribution unit (PDU) and a UPS (Uninterruptable Power Supply) that are used by internet service providers are studied. Capsa Free network analyzer and Wireshark network protocol analyzer were used as supporting tools. A working model of an IP network in GNS3 has been created through which this research has been carried out. In addition to checking whether the exchanged information is secure, a characterization of the generated traffic has been made, showing results for the generated traffic and which ports generate the most traffic. These carried-outstudies show that the exchanged information is not secure. As a way to secure the exchanged information, the use of VPN (Virtual Private Network) technology is proposed; thanks to a VPN, the exchange of information is secure. The obtained results confirm this and validate the applicability of GNS3 to test/study whether data exchange between power electronic devices and a control center is secure.

Power System Control Centers and Their Role in the Restoration Process after a Major Blackout

Power control centers have evolved since their ground-breaking inception in the 1960s, and they are extremely important for the operation of the power system, ensuring maximum reliability. There has been much discussion about mandating reliability requirements, but for the most part, reliability standards are already in place for electricity grid design and operation. Unfortunately, these standards do not examine in detail monitoring and control, possibly due to the false belief that reliability primarily comes from redundancies in transmission and generation. The grid can operate even more closely to its limits thanks to improved grid control and monitoring, which also increase reliability. In this paper, the significant role of the power system control centers in the event of a major blackout is discussed, proving their significance in the restoration process.

Corrigendum: Static equivalent of distribution network with distributed PV considering correlation between fluctuation of PV and load

Incorrect AffiliationIn the published article, there was an error in affiliation(s) [1,2]. Instead of “[Electric Power Research Institute, State Grid Shandong Electric Power Company, Jinan, China; Shandong Electric Power Company, State Grid Corporation of China, Jinan, China]”, it should be “[Power Grid Technology Center, State Grid Shandong Electric Power Research Institute, Jinan, China; Shandong Electric Power Dispatching and Control Center, State Grid Shandong Electric Power Company, Jinan, China]”. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.Incorrect Author NamePlease also check that the initials used in the Author Contributions section or elsewhere in the article are correct. In the published article, an author name was incorrectly written as [Kang Zhao2]. The correct spelling is [Kang Zhao1]. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.

Harmonics Extraction Scheme for Power Quality Improvement Using Chbmli-Dstatcom Module

In recent day’s power distribution system is distress from acute power quality issues. In this work, for compensating Power Quality (PQ) disturbances a seven level cascaded H-bridge inverter is implemented in distribution static compensator which protects power quality problems in currents. Distribution Static Compensator (DSTATCOM) aid to enhances power factor and removes total harmonic distortion which is drawn from non-linear load. The D–Q reference theory based hysteresis current controller is employed to generate reference current for compensation of harmonics and reactive power, additionally Probabilistic Neural Network (PNN) classifier is used which easily separates exact harmonics. In the meantime fuzzy logic controller is also used to maintain capacitor DC-link potential. When comparing to PI controller it decreases steady state time and reduces maximum peak overshoot. Cascaded H-bridge multilevel inverter converts direct current to Alternating current, through inductor opposite harmonics are injected in Power Control Centre reduces source current harmonics and reactive power. The implementation of CHBMLI in distribution STATic COMpensator simulation model is simulated by means of MATLAB.

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Analysis and Advance Implementation of Automatic Power Factor Corrector Unit (APFC) for an Industrial Application

In today's evolving and limitless world where companies are growing rapidly, technology and control are needed. Our machines and equipment’s that required technology as well as superior controlling powering and protection for excellent output and efficiency. In this project we are especially taking look at the powering part. What is needed to control machine and equipment’s? The answer is "pcc panel”, i.e., power control center. Now what is that? It is basically cabinet which contains electrical components to control the various equipment’s, motors etc. PCC acts as gateway for electrical line. Today they are used in almost each and every industrial and commercial applications, control panels also gives protection to our equipment’s and machines.

A Practical GERI-Based Method for Identifying Multiple Erroneous Parameters and Measurements Simultaneously

Even with modern smart metering systems, erroneous measurements of the real and reactive power in the power system are unavoidable. Multiple erroneous parameters and measurements may occur simultaneously in the state estimation of a bulk power system. This paper proposes a gross error reduction index (GERI)-based method as an additional module for existing state estimators in order to identify multiple erroneous parameters and measurements simultaneously. The measurements are acquired from a supervisory control and data acquisition system and mainly include voltage amplitudes, branch current amplitudes, active power flow, and reactive power flow. This method uses a structure consisting of nested two loops. First, gross errors and the GERI indexes are calculated in the inner loop. Second, the GERI indexes are compared and the maximum GERI in each inner loop is associated with the most suspicious parameter or measurement. Third, when the maximum GERI is less than a given threshold in the outer loop, its corresponding erroneous parameter or measurement is identified. Multiple measurement scans are also adopted in order to increase the redundancy of measurements and the observability of parameters. It should be noted that the proposed algorithm can be directly integrated into the Weighted Least Square estimator. Furthermore, using a faster simplified calculation technique with Givens rotations reduces the required computer memory and increases the computation speed. This method has been demonstrated in the IEEE 14-bus test system and several matpower cases. Due to its outstanding practical performance, it is now used at six provincial power control centers in the Eastern Grid of China.

An optimal scheduling scheme for smart home electricity considering demand response and privacy protection

The implementation of demand response can not only ensure the stability of power system, but also reduce the cost of user’s power consumption. However, the real-time, fine-grained bi-directional communication between smart meters of smart homes and the power control center may lead to the privacy leakage of users. Aiming at the problems above, an optimal scheduling scheme for smart home electricity considering demand response and privacy protection is proposed. First of all, the smart home load models are established under two kinds of demand response, and then the BAS algorithm is used to get the lowest cost of electricity consumption. In addition, the user’s privacy are protected with the help of energy storage of electric vehicle to blur user’s electricity consumption data, and a privacy quantification method with adjustable weight is given. The simulation results show that the scheme can significantly reduce the user’s electricity cost by arranging household electricity reasonably in response to power grid DR, the users can also adjust the value of privacy protection weight α to meet their privacy and cost requirements.

Research on Real-time Application of Ubiquitous Power Internet of Things Information Based on Smart Sensor Technology

In view of the current situation that it is difficult for the power control centre to take into account the multi-source information to conduct effective risk assessment on the dynamic process of the power grid, the challenges and opportunities faced by the power grid risk assessment under the background of the ubiquitous power Internet of Things are pointed out. The framework of the dynamic risk assessment system for the grid of the Internet of Things. At the same time, in view of the monitoring and fault diagnosis functions of sensor technology, especially gas sensor in transformer oil chromatographic monitoring, the application of ubiquitous power Internet of Things sensor technology in online monitoring of power equipment is discussed. First, the application of online monitoring of power equipment is analysed. The inevitable trend will then discuss in detail the monitoring and fault diagnosis functions of gas sensor technology in transformer oil chromatographic monitoring from sensor technology, gas sensor, transformer oil chromatographic device, and gas analysis method.

Framework and technologies of App store in new generation power grid dispatching and control system

In the existing power grid dispatching and control system, the management mechanism of the software version is incomplete; the software quality is difficult to guarantee; the level of automation of the software release is low; the feedback mechanism of the software usage is lacking. So it is difficult to meet the openness requirements of New Generation Power Grid Dispatching and Control System (NGPGDCS). In this paper, we propose a framework of app store for NGPGDCS, and give some specific introductions to key technologies such as app review and release process, app precise recommendation and download, app intelligent upgrade, and app evaluation feedback. This solution has been piloted in some power grid dispatching and control centers at provincial level and above. Practice has proved that this solution helps to improve the quality of apps, enhance the degree of software automation release, and promote the continuous improvement of the quality of apps.

A privacy protection scheme of smart meter for decentralized smart home environment based on consortium blockchain

In order to ensure the reasonable dispatch and utilization of power in smart homes, decentralized smart homes need to send power information to the power control center, and the power control center need to send control instructions to smart homes. However, the bi-directional interaction between smart homes and the power control center may lead to a series of security problems, such as smart meters of smart homes collect fine-grained real-time power consumption data and upload it to the control center, which will lead to the leakage of users’ privacy. The existing schemes protect users’ privacy by signcryption and data aggregation usually, and elliptic curve bilinear pairing or exponential operation are used in most of them, whose computation costs is high. In addition, the existing schemes for centralized storage of power consumption data may result in some security problems, such as single point failure, malicious tampering of data, etc. Aiming at the problems above, a privacy protection scheme of smart meter for decentralized smart home environment based on consortium blockchain is proposed, elliptic curve point multiplication operation is used in the certificateless aggregated ring signcryption algorithm, which reduces the computing and communication costs; distributed storage of users’ data with consortium blockchain is used to solve the problem of single point failure and data tampering. Theoretical analysis proves that the scheme not only guarantees users’ privacy, but also has characteristics of confidentiality and unforgeability, and experiments show that the scheme has lower computing and communication costs.

Unsupervised Machine Learning-Based Detection of Covert Data Integrity Assault in Smart Grid Networks Utilizing Isolation Forest

Being one of the most multifaceted cyber-physical systems, smart grids (SGs) are arguably more prone to cyber-threats. A covert data integrity assault (CDIA) on a communications network may be lethal to the reliability and safety of SG operations. They are intelligently designed to sidestep the traditional bad data detector in power control centers, and this type of assault can compromise the integrity of the data, causing a false estimation of the state that further severely distresses the entire power system operation. In this paper, we propose an unsupervised machine learning-based scheme to detect CDIAs in SG communications networks utilizing non-labeled data. The proposed scheme employs a state-of-the-art algorithm, called isolation forest, and detects CDIAs based on the hypothesis that the assault has the shortest average path length in a constructed random forest. To tackle the dimensionality issue from the growth in power systems, we use a principal component analysis-based feature extraction technique. The evaluation of the proposed scheme is carried out through standard IEEE 14-bus, 39-bus, 57-bus, and 118-bus systems. The simulation results show that the proposed scheme is proficient at handling non-labeled historical measurement datasets and results in a significant improvement in attack detection accuracy.

Optimal Configuration of Interdependence Between Communication Network and Power Grid

Smart grid is a cyber-physical system with interdependent power grid and communication network. Such interdependence make the smart grid fragile against cascading failures, where an initial failure in communication network may lead to further failures in power grid, and vice versa. We prevent such inter-network cascading failure by stopping an initial failure from propagating. This is achieved by providing a sufficient number of power-disjoint communication routes between power nodes and control center. The number of power-disjoint routes is a robustness metric. We aim to maximize robustness by configuring the interdependence relationship between power grid and communication networks. Such relationship indicates which power node supplies energy to which communication node, and which communication route is used to connect which power node to the control center. Following Menger's Theorem, we transform such configuration problem into a Maxflow problem and solve it using the simplex algorithm. We have evaluated the proposed method through extensive simulations. The results confirm the optimality and computational efficiency of the proposed method. The number of power-disjoint routes increases with an increase in the network size, but can never exceed the number of node-disjoint routes for a same network.

Analysis of Power System Vulnerability Considering Multiple Disturbances Corresponding to Information and Physics

With the continuous development of smart grid, the automation degree of power system continues to improve. The number of measurement-calculating and decision-controlling units of the power grid has greatly increased, and the scale of the power information network has become larger and larger. The stable operation of the power system is inseparable from the real-time dispatch of its information system. As the key infrastructure, power system has a huge impact on national security, economic development and social stability, and has become one of the key targets of terrorist destruction. In view of the fact that information network and power network integrate with each other currently, this paper focus on the functions of the power control center, modeling information systems together with physical systems. Considering that the power system has suffered multiple disturbances corresponding to information and physics, the quantitative analysis method is used to simulate the dynamic evolution process after the accident, and the loss of load is used as the evaluation index to analyze the vulnerability of the power system, to find the vulnerable components of the power grid. So effective protection measures can be taken to reduce the loss of the power system after this type of destruction. The constructed model is solved by mixed integer nonlinear programming method. IEEE Reliability Test System-24 verifies the feasibility and effectiveness of this model.

Cost-effective telemetry for energy network of an electricity distribution company: part I

We present a novel application of radio frequency wireless mesh network and general packet radio service technologies in a telemetry solution to measure power flow in the energy network of an electricity distribution company. The telemetry solution utilizes some selected circuits of grid stations and calculates total power consumed, total power imported, and total power exported by the distribution company. The selection of circuits for sensors installation is the key for reducing solution cost as compared to the case when sensors are installed on all the power output points. The framework involves installation of specially developed energy sensors (smart energy meters) and data concentrator units at the selected grid stations for measurement of energy data that include active energy, reactive energy, active power, apparent power, current, voltage, and power factor. The measured data reach the data concentrator unit using a 433-MHz wireless mesh network and are transmitted to a remote power control center using general packet radio service. Energy data from different grid stations across the energy network are collected at the power control center and utilized in calculation of total power consumed, total power imported, and total power exported. The approach has been tested on two electricity distribution companies of Pakistan: the Islamabad Electric Supply Company and Peshawar Electric Supply Company. Also in this work, the result of overload detection based on a generalized likelihood ratio test for an industrial feeder of the Islamabad Electric Supply Company is included. Detection probability of 0.96 with a false alarm probability of 0.04 has been achieved for a 30-min data interval.

Design and microcontroller‐based hardware performance analysis of a security‐enhanced lightweight communication scheme for smart grid

In smart grid, usage reports of consumers are collected via the smart meters (SMs) and sent to the power management and control center. In addition, some instructions are sent from the control center to the SMs. These two‐way communications between customers and energy suppliers are subject to numerous security threats. Due to the limited processing capability and storage space of the SMs, it is required to employ lightweight communication schemes. To do so, quite recently, Liu et al have proposed an interesting lightweight authenticated communication scheme for the secure bidirectional communications of SMs and neighborhood gateways in smart grid. In this paper, we first demonstrate that their scheme suffers from the SM's memory modification attack and pollution attack, then, we propose an enhanced lightweight communication scheme that is secure against the mentioned attacks. The comparative performance analysis with recent works in this field shows that our scheme not only is more efficient in terms of computational complexity and communication cost, but also benefits from substantial reduction in the required storage space. Our realistic hardware implementation on two popular microcontrollers confirms this claim.

A Smarter Grid Operation: New Energy Management Systems in China

The power grid in China has been developing rapidly with the improvement of the national economy and standard of living. By the end of 2016, China's installed power generation capacity had reached 1,646 GW . Currently, China?s power grid has the largest installed capacity, the highest voltage level [1,000 -kV ultra-high voltage (UHV)], and the largest annual power generation in the world. The operation of such a large-scale power grid poses many major challenges for electric power control centers.

Power Distribution Design of MicroSat Power Control Unit Elegant Bread Board (EBB)

The Power Control Unit (PCU) in Micro-satellites program proposed to develop by NSPO, acts as the satellite power control and distribution center. One of the modules in the PCU, named the Power Distribution (PD), the main function provides the rated voltage and current of each power outlet for the satellite subsystem. When overload or short-circuit happens and persists for a time period, PD will limit the load current in a pre-designed value, and shut off the load to avoid damage on essential devices. In this paper, we will introduce the PCU EBB function and circuit design of PD.

Abductive identification of bad data: methodology and field test

This study describes a solution to discriminate the original sources of bad data which are concerned by the substation maintainers. Bad data caused by defects of monitoring system, such as mal-setting of monitoring devices or time skew, are concerned here. These bad data can be identified mostly in electric power control centre by bad data identification (BDI) methods including robust state estimation; however, these methods can hardly explain the relevant original sources of bad data in substations. Here, the authors propose a data-driven method named abductive identification (AbI) to discriminate the original sources of bad data already identified by BDI methods. In the AbI method, feature patterns of bad data, based on their residuals, are investigated. A feature pattern selection method for bad data is then proposed, in which both the absolute residual and relative residual are considered. Based on this feature selection approach, a Bayesian classifier is developed to identify the original sources of bad data. A two-level architecture for the AbI approach is introduced to deal with diverse bad data patterns of wide-area networks. Simulation and field test results demonstrate the applicability of the proposed method.