Power System Communication Research Articles

A Novel Approach to Investigate the Impact of Hetero-High-K Gate Stack on SiGe Junctionless Gate-All-Around (JL-GAA) MOSFET

It is a well-known fact that the gate stacking is used to improve the electrostatic behavior of Si0.5Ge0.5 Junctionless Gate-All-Around (JL-GAA) MOSFETs. In gate stacking, the high-k oxide material is stacked with an interfacial silicon dioxide (SiO2) layer. In the recent past, oxide engineering techniques have been investigated as an alternative approach to improve the driving current of JL-GAA MOSFETs. In this paper, oxide engineering has been applied to improve the electrostatic performance of JL-GAA MOSFETs. The comparative study of the three device structures, namely Double Hetero gate oxide (DHGO), Triple Hetero gate oxide (THGO), and Quadruple Hetero gate oxide (QHGO) has been performed for various performance parameters. The objective behind this investigation is to highlight a significant enhancement in the driving current of JL-GAA MOSFETs. The comprehensive analysis shows that the DHGO device offers the highest ON-current, lowest subthreshold swing, and DIBL. Hence, the proposed device will be a perfect match for low power and high-speed communication systems.

Research on key technologies for fault knowledge acquisition of power communication equipment

Abstract With the development of Energy Internet and Smart Grid, power communication equipment has gradually become an important pillar supporting the information transmission. However, when equipment failure occurs, more and more attention has been paid to the rapid realization of equipment fault research and judgment from a large amount of equipment fault information. Based on the fault data of power communication equipment, a fault model of power communication equipment is designed in this paper. It combines BERT and BiLSTM-CRF model for knowledge extraction, and constructs the equipment fault knowledge graph to realize the visual display of power communication equipment. Through this model, fault knowledge extraction can be realized accurately, and a visual model of fault analysis can be formed, which can effectively improve the fault research speed and work efficiency of maintenance personnel.

Load balancing selection method for heterogeneous power communication equipment based on software defined network

In order to overcome the problem of poor load balance of power heterogeneous communication equipment, this paper proposes a software defined network (SDN)-based load balance selection method for po...

Load balancing selection method for heterogeneous power communication equipment based on software defined network

Load balancing selection method for heterogeneous power communication equipment based on software defined network

Artificial Intelligence Based Intrusion Detection System for IEC 61850 Sampled Values Under Symmetric and Asymmetric Faults

Modern power systems require increased connectivity to implement novel coordination and control schemes. Wide-spread use of information technology in smartgrid domain is an outcome of this need. IEC 61850-based communication solutions have become popular due to a myriad of reasons. Object-oriented modeling capability, interoperable connectivity and strong communication protocols are to name a few. However, power system communication infrastructure is not well-equipped with cybersecurity mechanisms for safe operation. Unlike online banking systems that have been running such security systems for decades, smartgrid cybersecurity is an emerging field. A recent publication aimed at equipping IEC 61850-based communication with cybersecurity features, i.e. IEC 62351, only focuses on communication layer security. To achieve security at all levels, operational technology-based security is also needed. To address this need, this paper develops an intrusion detection system for smartgrids utilizing IEC 61850‘s Sampled Value (SV) messages. The system is developed with machine learning and is able to monitor communication traffic of a given power system and distinguish normal data measurements from falsely injected data, i.e. attacks. The designed system is implemented and tested with realistic IEC 61850 SV message dataset. Tests are performed on a Modified IEEE 14-bus system with renewable energy-based generators where different fault are applied. The results show that the proposed system can successfully distinguish normal power system events from cyberattacks with high accuracy. This ensures that smartgrids have intrusion detection in addition to cybersecurity features attached to exchanged messages.

Detecting Electromagnetic Geographical Environment Changes Based on the Frequency‐Intensity Curve

Electromagnetic geographic environment is closely related to human life. With continuous popularization of public infrastructures and daily electronic instruments, such as electric power communication systems and household appliances, electromagnetic radiation sources have increased sharply in the geographic environment, which leads to increasingly serious electromagnetic radiation pollution. Thus, it is significant to monitor, evaluate, and analyze the electromagnetic radiation condition and explore its changing law in the environment. However, the traditional monitoring method can only detect anomalies within certain frequencies in the fixed stations. To fill this gap, this research first develops a vehicle‐mounted electromagnetic environment monitoring system to collect both spatial positioning data and electromagnetic data of the whole frequency range. The acquired data are then used to construct the location‐based frequency‐intensity curve to reflect the variation of electromagnetic radiation at different frequency ranges. On this basis, a curve similarity measurement method is introduced to analyze the similarity of different curves, which is effective to diagnose time‐varying sources from both global and local perspectives. This research provides a real‐time mobile monitoring method, which is significant to know the dynamic variation of local electromagnetic environment and promotes subsequent comprehensive geographic analyses.

Analysis of curved thin wires radiating over a layered medium and some engineering applications

The paper deals with modelling of radiation from arbitrarily shaped thin wires above a multilayer and related engineering applications. The formulation is based on the set of corresponding Pocklington integro-differential equations (IDEs) for curved wires. The influence of lower layered half-space is taken into account by means of simplified reflection coefficient stemming from modified image theory (MIT). The set of coupled IDEs is handled via Galerkin Bubnov variant of indirect boundary element method (GB-IBEM) for curvilinear elements. The related field radiated from a wire configuration is obtained from corresponding integral expressions including integration of the currents along a given wire configuration. Some illustrative computational examples for certain wire configurations pertaining to dipole antennas, power communication systems (PLC) and instrumental landing systems (ILS) are given in the paper.

Assessment of the robustness of cyber-physical systems using small-worldness of weighted complex networks

This paper extends the definition of Small-worldness to weighted complex networks and uses it to assess the robustness of Cyber-physical Critical Infrastructure Systems (CPCIS) and consequently to identify system critical components. System uncertain parameters – electric power system loading and communication network latency, are first incorporated in the model, and small-world property indices – Characteristic Path Length, Clustering Coefficient, and small-worldness are assessed in their dynamic (time-varying) forms to represent real-time uncertain criticalities, evaluated using probability distribution functions. The most critical physical and cyber system components are then identified, and their dependencies on physical and/or cyber system are identified. It was clearly demonstrated that the CPCIS components are mutually dependent on each other and that this dependency (represented by the drop of dynamic small-worldness in one system if a failure occurs in the other system) might vary from bus to bus. The proposed methodology is illustrated on a realistic interconnected 1326-bus transmission network and 88 bus star-connected ICT network, divided into 6 control zones.

The Impact of Virtualisation Techniques on Power System Control Networks

Virtualisation is a concept successfully applied to IT systems. In this work, we analyse how virtualisation approaches, such as edge computing, brokerage and software-defined networking, can be applied in the area of electricity grid management and control systems. Power system information and communications technology is currently subject to significant changes. Networked power grid components including renewable energy units, electric vehicles and heat pumps need to be integrated into grid management systems. We studied how virtualisation techniques can support system operators in increasing an energy and communication system’s dependability and situational awareness, and how manual (mostly field-level) configuration and engineering efforts can be reduced. Starting from a working hypothesis, three concrete use-cases were implemented and the performance enhancements were benchmarked to allow for well-informed answers to the questions above. We took a close look at application-protocol-independent redundancy, grid-based routing and online system integrity control. In these study cases, we found significant improvements could be achieved with virtualisation in terms of reduced engineering effort, better system management and simplification in high-level system architecture, since implementation details are hidden by the virtualisation approach.

AoI-Optimal Joint Sampling and Updating for Wireless Powered Communication Systems

This paper characterizes the structure of the Age of Information (AoI)-optimal policy in wireless powered communication systems while accounting for the time and energy costs of generating status updates at the source nodes. In particular, for a single source-destination pair in which a radio frequency (RF)-powered source sends status updates about some physical process to a destination node, we minimize the long-term average AoI at the destination node. The problem is modeled as an average cost Markov Decision Process (MDP) in which, the generation times of status updates at the source, the transmissions of status updates from the source to the destination, and the wireless energy transfer (WET) are jointly optimized. After proving the monotonicity property of the value function associated with the MDP, we analytically demonstrate that the AoI-optimal policy has a threshold-based structure w.r.t. the state variables. Our numerical results verify the analytical findings and reveal the impact of state variables on the structure of the AoI-optimal policy. Our results also demonstrate the impact of system design parameters on the optimal achievable average AoI as well as the superiority of our proposed joint sampling and updating policy w.r.t. the generate-at-will policy.

A wide tuning range, low noise oscillator with FoM of -188 dBc/Hz in 45 nm CMOS

A wide tuning range, low phase noise oscillator with 3 stage differential configuration is presented. GPDK 45 nm CMOS Technology is selected for the design and simulation of the proposed circuit, under power supply impediment of 1.1 V. Proposed delay cell features ultra wide tuning range as it utilizes dual control voltages (Vc1 and Vc2), enabling large current to flow in the circuit. As frequency of oscillation has linear proportionality with the bias current, this oscillator generates frequencies from 534 MHz to 18.56 GHz. The proposed circuit occupies chip area of 102.87μm2. This circuit offers power consumption of 1.13 mWatt and phase noise of −108.61 dBc/Hz (10 MHz offset frequency) at 5.82 GHz oscillation frequency. Performance of the proposed circuit is evaluated on various temperature, supply voltage and process corners. Total Harmonic Distortion (THD) profile is also measured through simulation. Because of wide frequency spectrum, low phase noise, small area and low power budget, proposed circuit can be utilized in various power electronic applications, medical equipments, communication and navigation systems.

Reinforcement Learning Based Adaptive Resource Allocation for Wireless Powered Communication Systems

Wireless powered communication (WPC) is one of the promising techniques for future energy-constrained wireless networks. In this letter, we consider a WPC system composed of a hybrid access point and an energy harvesting node (EHN). In this system, we propose a reinforcement learning based adaptive resource allocation scheme that dynamically assigns the channel resources to minimize the outage probability of information transfer while satisfying the average power constraint at the EHN, which is formulated as a constrained Markov decision process (MDP) problem. To solve this challenging problem, we first transform the originally formulated problem into its equivalent unconstrained MDP with multi-objective. Then, to find the resource allocation policy, we propose a novel Q-learning algorithm. Numerical results demonstrate the superior performance and effectiveness of the proposed scheme.

Theoretical investigation of bending loss in step-index plastic optical fibers

Behavior of the step-index plastic optical fibers (SI POFs) is examined in a straight-curved configuration for various launching conditions and fiber curvature. This was achieved by applying the power flow equation to calculate the power distribution at the end of the straight fiber segment that precedes the curved one, allowing calculation of the power loss for the latter. We have shown that a small bend radius (r<0.04 m) and launch angles close to the critical angle should be avoided when using this type of SI POF in power delivery and communication systems. These results may be useful when choosing between various operating fiber conditions in order to prevent possibly high bending-induced losses.

Research on Energy Internet Power Line Communication Technology Based on Block Chain

With the continuous development of energy Internet technology, its requirements for communication systems are getting higher and higher. As for the energy Internet, it is based on the concept of the Internet and the existing smart grid. Its communication system also needs to rely on the existing power communication system. In the energy Internet, the use of block chain and intelligent contract technology to meet credible and automatic point-to-point energy transactions can improve the overall operating efficiency of the system, reduce management costs, and make the energy Internet a self-organizing and self-regulating structure. In essence, energy Internet and block chain technology must be built on the Internet of Things, a common intelligent device. This paper takes the power line communication technology of the Internet in the current power system as the research object, analyzes the main challenges and problems in the construction of energy Internet based on blockchain, and then provides the corresponding research basis for the future heterogeneous network integration.

A security-based observability method for optimal PMU-sensor placement in WAMS

Optimal PMU placement (OPP) problem is one of the most important issues in wide area measurement systems (WAMS). Delivering the measured data to the control center is possible through communication infrastructure (CI) that is a part of the WAMS. However, to well estimate the state of the system, observability of the measurement system is necessary. In this paper, a security-based observability (SBO) method for the PMUs and related CI is proposed. A hybrid wireless sensor-based structure including energy harvesting sensor nodes (EHSNs) and plug-in powered sensor nodes (PPSNs) is utilized as the communication system. The contingency-constraint optimal PMU placement and related sensor-based CI is proposed and formulated. To increase the reliability of the CI, a reliability index for the wireless sensors is added as a constraint to the objective function which includes the total cost minimization subject to power system observability and communication constraints. The effect of zero-injection buses (ZIBs) and radial buses in the power system are also included in the model to get more practical results. A mixed-integer linear programming (MILP) is used for contingency constraint PMU placement and a binary-coded genetic algorithm (BCGA) is accordingly used for solving the examined communication optimization. The IEEE 13-bus and IEEE 37-bus test feeder systems are utilized to evaluate the effectiveness of the proposed method.

SDN‐based teleprotection and control power systems: A study of available controllers and their suitability

SummaryWith the popularization of the smart grid paradigm, substation automation technology has gradually been upgraded with additional processing and communication capabilities within control and protection devices. Hence, the research community is pressured to find new, efficient, and reliable communication solutions for such a scenario. That task is complicated by the stringent temporal requirements defined by the International Electrotechnical Commission (IEC) 61850 standard for power system communication comprising teleprotection schemes. Further compounding the issue is the critical nature of the power grid, in which availability is definitely a strong requirement. Software‐defined networking (SDN) may provide powerful tools to fulfill those requirements at acceptable costs. As such, this paper surveys and compares several available SDN controllers and their applicability to the teleprotection scenario. It further evaluates controllers in terms of capacity and resilience through experiments in an emulated environment.

Study of Microgrid Resilience Through Co-Simulation of Power System Dynamics and Communication Systems

Smart grid technologies are deepening the interdependence of electric power and communication systems, but that interdependence is difficult to quantify. In the case of microgrids, communication systems can be essential to maintaining stability during islanded operations. Though many power system studies assume the presence of perfect communication networks, detailed modeling of power and communication systems for dynamic studies of microgrids is rare. This article develops a framework, for power and communication system co-simulation, to study the effects of communication systems on microgrid stability. An operational use case is examined, in which a battery energy storage system operates to offset the loss of generation in an islanded microgrid. The framework is evaluated for different communication technologies, network structures, and communication media.

Risk Element Identification of Grid Communication System Based on Improved Bayesian Network under SG and UPIOT

Now, Smart Grid and Ubiquitous Power Internet of Things are booming in China. The degree of coupling between the grid and the power communication system determines the degree of development of Smart Grid and Ubiquitous Electric Internet of Things. The rapid growth of Smart Grid has resulted in the risk transfer of Smart Grid Communication Systems with many levels and a strong correlation of indicators. This paper sorts out the risk indicators and provides a three-layer risk transfer network considering equipment, environment, business and operational dimension. Moreover, the triangular fuzzy number and DS evidence theory are used to assign the Bayesian network root node probability. At last, this paper identifies the risk element of SGCS and proposes preventive measures.

Decentralized Networked Load Frequency Control in Interconnected Power Systems Based on Stochastic Jump System Theory

Random transmission delay and packet loss may cause load frequency control (LFC) performance degradation or even instability in interconnected power systems. Traditional robust methods mainly focus on guaranteeing the asymptotic stability with pre-estimating a maximum delay case. As a result, the designed controller cannot satisfy the actual operational requirements completely since the improper network performance estimation. In this paper, based on jump system theory, the state-space model for LFC system with the different transmission delay is established as the jumping decision variable, which describes the possible dynamics of the networked LFC system with the bounded time delay. Secondly, in order to avoid the defect of conservative or optimistic design caused by imprecise pre-set delay, the upper boundary of the transmission delay in the power communication system is calculated by deterministic network theory. Furthermore, the asymptotic stability constraints in bilinear matrix inequality forms are deduced via construction of a Lyapunov function. Moreover, to reduce the peak value, peak time and setting time of frequency deviations caused by power mismatches, an iterative optimization algorithm is proposed to obtain the optimal feedback matrix. Simulation studies with two-area and five-area interconnected power systems show that the proposed method can avoid optimistic or conservative design effectively while the stability and dynamic performance can be ensured simultaneously.

On the Throughput of Interference-Based Wireless Powered Communications With Receive Antenna Selection

We propose an interference-based wireless powered communication system in which an energy constrained source harvests energy from a single dominant co-channel interferer and then transmits information to a destination equipped with N receive antennas. Assuming interference dominates noise power at the destination and the receive antenna that maximizes the signal-to-interference ratio is selected, we investigate the average throughput for the delay-limited and delay-tolerant transmission modes. In particular, we derive an analytical expression of the average throughput for the delay-limited transmission mode, and a precise lower bound on the average throughput for the delay-tolerant transmission mode. Furthermore, we derive simplified asymptotic expressions of the average throughput for both transmission modes assuming asymptotically large number of receive antennas (i.e., N → ∞). We use the obtained asymptotic expressions to derive insightful closed-form expressions for the optimal energy harvesting time, which maximizes the average throughput, for both transmission modes. We show that the throughput-optimal energy harvesting time for the delay-limited and the delay-tolerant transmission scale like O(1/√N) and O(1/log(N)), respectively, for asymptotically large N.