Self-healing Control Research Articles

Development and Application of Smart Distribution Grid Self-Healing Control System

Self-healing is an important feature of smart distribution grid. Self-healing control for smart distribution grid covers risk prevention and operation optimization before accidents, in addition, it covers fault location, fault isolation and power restoration. The research of self-healing control theory, risk assessment, fault diagnosis and safety warning for smart distribution grid provides technical supports to help build a safe, reliable, efficient, high-quality, flexible and compliant smart distribution grid.

Self-Healing Control for a Class of Uncertain Power Distribution Network Based on Fuzzy Sets Theory

The self-healing control problems attract many concerns of researchers who major in power distribution network. This paper proposes a novel self-control method for a class of power distributed network with uncertainties. The fuzzy set idea is introduced to solve the uncertainties considered here. The efficiency of the proposed method is demonstrated by simulation results.

Comprehensive Operational Planning Framework for Self-Healing Control Actions in Smart Distribution Grids

Self-healing is a major driving force in the smart grid vision. This paper proposes a comprehensive design and operational planning framework to generate optimum self-healing control actions in a distribution system. For this purpose, a distribution system with optimally allocated distributed generators (DGs) is divided into a set of microgrids with high self-adequacy through allocation of distributed energy storage resources (DESRs) and distributed reactive sources (DRSs). Afterwards, by using the predicted load and generation of renewable-based distributed generators for the next hour of the day and other important factors (self-adequacy in the unfaulted microgrids, total distribution system's energy losses and the total supplied loads according to their requested reliability), the optimum self-healing strategy is planned for the system for all possible future faults. The IEEE 123-bus distribution system is selected as the test system; optimum microgrids are designed and several case studies are presented to demonstrate the effects of optimization coefficients on the optimum self-healing control actions.

An Intelligent Control Scheme to Support Voltage of Smart Power Systems

The intelligent control of power systems is one of the main tasks for realizing a smart grid. Because of the high-dimensional dynamics and discrete control of power systems, realizing an optimal control to support system voltages is a hard combinatorial optimization problem. In this paper, a new intelligent scheme based on a genetic learning progress for optimal voltage control is proposed. This learning control scheme combines the genetic algorithm (GA) with a memory which saves knowledge accumulated from past experiences. In each run of search by GA, past experiences in memory is exploited to speed up the searching of GA and improve the quality of the solutions while the knowledge in memory is also refined by the new solutions. With the help of this learning capability, a fast and self-healing voltage control is realized and the control performance can be improved gradually over time. A case study on the New England 39-bus power system showed that the purposed learning control can successfully prevent the system from voltage instability and at the same time a fast and adaptive system response is provided.

A 10-Bit 2-GS/s DAC-DDFS-IQ-Controller Baseband Enabling a Self-Healing 60-GHz Radio-on-Chip

A 10-bit 2-GS/s mixed-signal baseband (BB) circuit, which enables a self-healing 60-GHz 4-Gb/s radio-on-chip implemented in a 65-nm complementary metal-oxide semiconductor, is described. The BB circuit autonomously senses and optimizes transmitter (TX) P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub> , OIM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> , and image suppression, reducing the yield loss because of process variations. On-chip test tones are generated using a 10-bit 2-GS/s current-steering digital-to-analog converter (DAC) and direct digital frequency synthesizer (DDFS). Using the generated test tones, the aforementioned impairments are measured by an envelope detector at the power amplifier output. Based on this information, the programmable digital IQ phase amplitude and offset controller (IQ_CTRL) in the BB circuit improves the TX image suppression from -32.4 to -42.6 dBc, and digital control signals generated by the on-chip self-healing controller heal the TX P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub> and OIM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> from 9.5 to 13.2 dBm and from -32.5 to - 40 dBc, respectively. In terms of achieving the target specifications, namely, TX image suppression , , and , healing increases yield on ten dies from 0% to 100%. The BB circuit consumes only 49 mW, of which 37 mW comes from the DACs and 12 mW from the DDFS and the IQ_CTRL.

The Control and Analysis of Self-Healing Urban Power Grid

In this paper, the concept and system structure of the self-healing urban power grid (UPG) are presented. The proposed method has five operating states and four subcontrols, which are emergency control, restorative control, corrective control and preventive control. The entire self-healing UPG is controlled by the multiagent system (MAS). The agent system has three layers, each of which comprises several agents. This paper discusses the design and function of each agent, as well as the agents' structures and their communication methods. A practical test case based on the urban power grid in Jiangning County in China is employed to demonstrate the ability of the proposed agent-based system to perform self-healing functionality. Research findings indicate that the self-healing control system proposed in this paper can intelligently adjust the operating state to eliminate all the potential threats, and thus achieving the desired operation objectives.

Self-Healing Control Flow Protection in Sensor Applications

Since sensors do not have a sophisticated hardware architecture or an operating system to manage code for safety, attacks injecting code to exploit memory-related vulnerabilities can present threats to sensor applications. In a sensor's simple memory architecture, injected code can alter the control flow of a sensor application to either misuse existing routines or download other malicious code to achieve attacks. To protect the control flow, this paper proposes a self-healing scheme that can stop attacks from exploiting the control flow and then recover sensor applications to normal operations with minimum overhead. The self-healing scheme embeds diversified protection code at particular locations to enforce access control in code memory. Both the access control code and the recovery code are designed to be resilient to control flow attacks that attempt to evade the protection. Furthermore, the self-healing scheme directly processes application code at the machine instruction level, instead of performing control or data analysis on source code. The implementation and evaluation show that the self-healing scheme is lightweight in protecting sensor applications.

Design and validation of an FPGA-based self-healing controller for hybrid machine tools

It has been recognised that the ability of dynamic reconfiguration and parallel computation for field programmable gate array (FPGA) provides significant advantages, particularly for increasing reliability and maintainability of electromechanical products. An FPGA-based self-healing controller for hybrid machine tools (HMTs) is developed to meet the high speed sampling rate requirement and a circuit of self-healing controllers as well as velocity profile generators for HMTs is designed using the very high speed integrated circuit hardware description language (VHDL) and implemented with an FPGA. A self-healing controller framework for HMTs is proposed and incorrectly measured leg position faults (LPFs) and incorrectly measured leg velocity faults (LVFs) are considered as examples. Faults are detected by fault detection and isolation (FDI) module considering the closed-loop kinematic chain constraints of spatial hybrid mechanism utilising a sensored passive leg. When a fault is detected, the control system and the desired joint space trajectory are reconfigured according to the nature of the isolated fault and the task is resumed to the largest extent possibility. Feasibility and performance of above self-healing controller are validated by experiments and simulation examples.

Restoration message transfer mechanism and restoration characteristics of double-search self-healing ATM network

The self-healing network is particularly interesting with regard to ATM networks, because the restoration time can be shortened by using the advantages of the ATM network. This paper studies a self-healing ATM network based on virtual path (VP) protection switching. First, a novel self-healing algorithm/spl minus/the double-search self-healing algorithm/spl minus/is proposed. It is shown that this algorithm can restore failed bidirectional VPs faster and find alternate VPs more effectively than existing self-healing algorithms. Second, it is shown that the restoration information for self-healing control (SHC) messages must be transferred by specific cells carrying the control and OAM information (Ic&o). Message parameters and a cell format are proposed. Third, evaluation of the restoration characteristics using the proposed self-healing algorithm by computer simulation indicates that good performance against a transmission link failure is obtained even in a large-scale network model with 110 nodes. The results also indicate that the VP group (VPG) method can improve the restoration time without reducing the restoration ratio.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Control protocol and its performance analysis for distributed ATM virtual path self-healing network

A restorable network comprised of a mesh of ATM virtual paths (AVPs) is expected to be superior to distributed SONET digital cross-connect self-healing networks in terms of restoration time. The paper presents a reliable protocol and evaluation of its performance for control information transfer in distributed AVP self-healing networks. Two error-recovery technologies for the data-link level (selective retransmission and go-back-N) in AVP networks are reviewed, and a model for evaluating the delay of the go-back-N method that has been used in existing terrestrial systems is derived analytically. The proposed analytic model is combined with a self-healing simulator for AVP mesh networks to evaluate the restoration time characteristics. Case study results for the worst-case scenario show that the total restoration time, including link-by-link error control for self-healing control messages, is expected to be less than 2 s, which is the time objective for complete restoration for a metropolitan LATA network. The results also show that the estimated average delay penalty for adding the link-by-link error recovery process is 7.5 ms for complete service restoration. >

Distributed self-healing control in SONET

This paper proposes a distributed self-healing architecture which contains two self-healing techniques. In this proposal, a path restoration by Self-Healing Ring (SHR) and a path restoration by Dynamic Self-Healing (DSH) algorithm are jointly applied in a network. In the architecture, SHR is applied for a part of a path which is terminated by an Add-Drop Multiplexer (ADM), and DSH is applied for another part of a path which is terminated by two Digital Cross-Connect Systems (DCSs). Based on the architecture, DSH can be applied for a part of a path which is terminated by an ADM. Next, a network design algorithm is described in order to optimize the amount of spare capacity. As a result, spare capacity reduction is realized by using the algorithm for a network where the proposed architecture is applied.

A Self-Healing Control

This article describes an electronic computer self-repair technique which does not require system duplication. It identifies the properties demanded of control hardware to effect this end and considers their practicability. It also decribes a prototype computer constructed to test the feasibility of this form of self-repair, and discusses test results.