Hot Backup Research Articles

Research on flexible uninterrupted neutral section passing system based on V-clamp multilevel converter

This paper proposes a novel flexible uninterrupted neutral section passing system based on four-leg V-clamp multilevel converter (VMC). It can better solve a series of problems such as overvoltage, overcurrent and speed loss caused by the interruptible over-phase scheme used in electrified railway, and compensate the negative sequence and reactive current in traction power supply system at the same time. VMC is a new type of multilevel converter with common DC-link capacitors. VMC has advantages in the number of devices to some extent, and its expansion from odd level to even level is very simple. Compared with schemes based on modular multilevel converter (MMC), this system has the advantages of low converter hardware cost and no energy loss resulting from hot backup. The system configuration, working process and operating principle are analyzed in detail, and a control strategy for the whole process of neutral section passing is designed. Next, the method based on zero-sequence voltage component injection is used to solve the voltage-balancing problem existed in multilevel converter with common DC-link capacitors, which does not need additional switching times and is easy to realize in three-phase three-wire system. Finally, the simulation results are given to verify the feasibility and effectiveness of the system.

Reliability Analysis and Redundancy Optimization of a Command Post Phased-Mission System

This paper divides the execution process of the command post system into four stages: information acquisition, information processing, decision control and response execution. It combines multilayer complex networks with a phased-mission system. Most studies have only evaluated the reliability of phased-mission systems. This paper evaluates and optimizes the reliability of a phased-mission system. In order to improve the mission success rate and maximize the reliability of a command post system, this paper provides a multitasking node criticality index, and the index is used to identify the key nodes in the command post’s four-stage network Then, the hot backup system of the node is selected to determine the redundant structure of the key node. Under the constraints of the operation and maintenance costs of key nodes, with the goal of maximizing the reliability of the information processing network layer, the multitask redundancy optimization model of each stage is established. Finally, the reliability of the missions before and after redundancy optimization is compared, using the case analysis of the four-layer network to verify the effectiveness of the proposed model.

A Method of Realizing the Reliable Operation of the Variable Frequency Drive – Hot Backup Switching

In this paper, a method to realize the reliable operation of the variable frequency drive(VFD)is proposed: Hot Backup switching, and the electrical design, software design and test results are given. And meanwhile, also state the switching control principle, clearly indicate the distinctive difference and improved performance between traditional switching mode and Hot Backup switching mode. At the end, gain the conclusion based on test results and extend to bigger size of motor.

КОНЦЕПЦІЯ INTERNET OF ENERGY ДЛЯ УПРАВЛІННЯ ОБ’ЄКТАМИ ЕЛЕКТРОМЕРЕЖ

Purpose. Determination of a promising way of managing electric networks in the conditions of an increase in the number of implemented distributed generation facilities using renewable sources. Dispatch systems are the object, methods of building dispatch systems are the subject. Methods. Research was carried out on the basis of system and elemental-structural approaches. Results. The article analyzes the subject industry and the evolution of energy facility management systems. The relevance of the work lies in the acute study of modern approaches to the management of electric power facilities, designed to change not only management methods, but also to generally revise the concept of modernization of existing systems and construction of new networks. It has been determined that information networks become not only the means of communication between people, but also open completely new ways of exchanging telemetric information regarding the management of technological processes between devices. The energy sector is no exception, where every year the penetration of telecommunication technologies is deepening, creating new approaches to the management of energy systems of electricity generation and distribution. The work considers ways of organizing network management and increasing its stability with a decrease in the level of inertia, based on the use of differential meters, the concept of hot backup, the use of intelligent forecasting and information exchange technologies, and the introduction of modern communication technologies, and parallels between the levels of power distribution and data transmission in information networks. Scientific novelty. It has been offered to increase the efficiency of management in electrical networks with distributed generation with the help of energy routers. Practical significance. The work proves that the IoE concept is the most promising for the use in power grids in the conditions of an increase in the number of distributed objects of small generation.

Optimization Model for Multiple Backup Resource Allocation With Workload-Dependent Failure Probability

This paper proposes a multiple backup resource allocation model with a workload-dependent failure probability to minimize the maximum expected unavailable time (MEUT) under a protection priority policy. The workload-dependent failure probability is a non-decreasing function which reveals the relationship between the workload and the failure probability. The proposed model adopts hot backup and cold backup strategies to provide protection. For protection of each function with multiple backup resources, it is required to adopt a suitable priority policy to determine the expected unavailable time. We analyze the superiority of the protection priority policy for multiple backup resources in the proposed model; we provide the theorems that clarify the influence of policies on MEUT. We formulate the optimization problem as a mixed integer linear programming (MILP) problem. We provide a lower bound of the optimal objective value in the proposed model. We prove that the decision version of the multiple resource allocation problem in the proposed model is NP-complete. A heuristic algorithm inspired by the water-filling algorithm is developed with providing an upper bound of the expected unavailable time obtained by the algorithm. The numerical results show that the proposed model reduces MEUT compared to baselines. The priority policy adopted in the proposed model suppresses MEUT compared with other priority policies. The developed heuristic algorithm is approximately 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> times faster than the MILP approach with 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> performance penalty on MEUT.

Microservice Monitoring and Handoff Algorithm Based on Dual-node Hot Standby

The service provider nodes in distributed microservice architecture often exit, join the network or have faults, which will affect the availability of the system. One of the main causes of the problem is the “bump” of service nodes. In this paper, a monitoring and switching algorithm based on dual-node hot backup is adopted, which makes the probability of bumping lower than the traditional single machine and switching method. Moreover, with the gradual increase of system scale, the performance of dual-node hot backup algorithm is still stable. Experimental results show that this method can effectively reduce the occurrence of service consumption node access failure events and improve the availability of the system.

Application of the Stacking and LACP Technology in Communications Networks

A key factor that has been winning market competitive advantage by carrier markets is how to solve the selection of equipments with lowest cost which provides a reasonable solution on network security and topology. By introducing the stacking technology, this paper gives a detailed explanation on how to use the lowest cost to solve the equipment selection problem and the devices’ hot backup. As the same time, it is shown that the network link aggregation hot backup is resolved by using the Link Aggregation Control Protocol (LACP). Once there is a failure in both a link and an equipment, the system would detect the failure and automatically switch to the backup link and equipment to ensure the network security.

Design Optimization of Dual‐Redundancy PM Brushless DC Motors for Torque Enhancement

AbstractTo enhance the torque of short‐time duty permanent magnet (PM) dual‐redundancy brushless DC motors (DR‐BLDCM) and avoid the motor overheating under a fixed outer diameter and length, a design method based on the optimization of split ratio and stator magnetic density (Bm) considering thermal limitations is presented. The global thermal limitation of DR‐BLDCM is set by limiting loss density. The local thermal limitation of the winding is set by limiting current density. The thermal limitations are taken as the boundary of torque enhancement design optimization. Both the cold backup and hot backup DR‐BLDCM are studied in this paper. By researching the relationship between torque, split ratio, and Bm, the optimal combination of split ratio and Bm are calculated analytically. The influences of thermal limitations on the maximum torque and the optimal combination are analyzed, and the principle to determine the optimal combination is obtained. The analytically calculated results are verified by finite element simulation, and the error is less than 6.82%. A prototype is manufactured based on analytical design results. The error between the calculated and measured copper loss is 6.96%. The verification results show that the proposed optimization method can fully enhance the torque of DR‐BLDCM under the condition of fixed overall dimension and thermal limitations. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Navigation Information Fusion in a Redundant Marine Rotational Inertial Navigation System Configuration

A Rotational Inertial Navigation System (RINS) redundant configuration is commonly adopted in high-accuracy marine navigation. Single-axis RINS and dual-axis RINS redundant configurations are good choices with single-axis RINS being a hot backup system, and are trade-offs between position accuracy, reliability as well as cost. However, lack of information fusion between systems is common. Therefore, a novel navigation information fusion method based on an augmented error state Kalman filter is proposed for a RINS redundant configuration. The azimuth gyro drift of a single-axis RINS whose influence cannot be averaged out by single-axis rotation can be estimated, whereby the deterministic position error can be predicted and compensated. Hence, the position accuracy in the event of dual-axis RINS failure can be guaranteed by improving the performance of a single-axis RINS. In addition, an online performance evaluation method is proposed to select the better performance dual-axis RINS as master RINS in a triple RINS configuration, including two sets of dual-axis RINS and a single-axis RINS, which is used in some particularly high reliability applications. Semi-physical simulations and experiments show the proposed method works well.

A polar-region-adaptable systematic bias collaborative measurement method for shipboard redundant rotational inertial navigation systems

The shipboard redundant rotational inertial navigation system (RINS) configuration, including a dual-axis RINS and a single-axis RINS, can satisfy the demand of marine INSs of especially high reliability as well as achieving trade-off between position accuracy and cost. Generally, the dual-axis RINS is the master INS, and the single-axis RINS is the hot backup INS for high reliability purposes. An integrity monitoring system performs a fault detection function to ensure sailing safety. However, improving the accuracy of the backup INS in case of master INS failure has not been given enough attention. Without the aid of any external information, a systematic bias collaborative measurement method based on an augmented Kalman filter is proposed for the redundant RINSs. Estimates of inertial sensor biases can be used by the built-in integrity monitoring system to monitor the RINS running condition. On the other hand, a position error prediction model is designed for the single-axis RINS to estimate the systematic error caused by its azimuth gyro bias. After position error compensation, the position information provided by the single-axis RINS still remains highly accurate, even if the integrity monitoring system detects a dual-axis RINS fault. Moreover, use of a grid frame as a navigation frame makes the proposed method applicable in any area, including the polar regions. Semi-physical simulation and experiments including sea trials verify the validity of the method.

Multi-Functional Mine Shaft Alarm System

As a component of multi-functional safety control, the man–machine mine shaft alarm system ensures safe conveyance of personnel and cargo in mines. The designed interfaces, circuits and architectures, hot backup and the objective-coordinated communication protocols guarantee strict orderliness, reliability and safety of mine control.

The Design of Data Disaster Recovery of National Fundamental Geographic Information System

Abstract. With the development of information technology, data security of information system is facing more and more challenges. The geographic information of surveying and mapping is fundamental and strategic resource, which is applied in all areas of national economic, defence and social development. It is especially vital to national and social interests when such classified geographic information is directly concerning Chinese sovereignty. Several urgent problems that needs to be resolved for surveying and mapping are how to do well in mass data storage and backup, establishing and improving the disaster backup system especially after sudden natural calamity accident, and ensuring all sectors rapidly restored on information system will operate correctly. For overcoming various disaster risks, protect the security of data and reduce the impact of the disaster, it’s no doubt the effective way is to analysis and research on the features of storage and management and security requirements, as well as to ensure that the design of data disaster recovery system suitable for the surveying and mapping. This article analyses the features of fundamental geographic information data and the requirements of storage management, three site disaster recovery system of DBMS plan based on the popular network, storage and backup, data replication and remote switch of application technologies. In LAN that synchronous replication between database management servers and the local storage of backup management systems, simultaneously, remote asynchronous data replication between local storage backup management systems and remote database management servers. The core of the system is resolving local disaster in the remote site, ensuring data security and business continuity of local site. This article focuses on the following points: background, the necessity of disaster recovery system, the analysis of the data achievements and data disaster recovery plan. Features of this program is to use a hardware-based data hot backup, and remote online disaster recovery support for Oracle database system. The achievement of this paper is in summarizing and analysing the common characteristics of disaster of surveying and mapping business system requirements, while based on the actual situation of the industry, designed the basic GIS disaster recovery solutions, and we also give the conclusions about key technologies of RTO and RPO.

Design and Implementation of Supporting IEEE1588 Industrial Ethernet Switch

Aiming at the reliability of real-time industrial Ethernet, the L2 Industrial Ethernet switch is designed using VSC7429. With the respect of real-time capacity, it is based on the IEEE1588 standard by adding logic modules between MAC £ ̈Medium Access Control£© layer and PHY £ ̈physical£© layer to process the clock stamp. It eliminates the delay and uncertainty of the protocol stack and provides the accurate synchronous clock. In terms of reliability, dual hot backup power supplies were applied. Owing to the harsh environment of the industrial field, the EMC (Electro Magnetic Compatibility) protection design was considered. The performance of the switch was tested including packet loss rate and bit error rate. Experimental results showed it met the requirement of industrial Ethernet standard.

The Application of ATCA Structure for Power Communication Switching System

In order to meet the needs of the power communication device This paper discusses the key technologies of the power switching equipment based on ATCA structure, including network topology selection and rack management system, as well as a system performance test result is given. The test results show that the power switching equipment based on ATCA structure has good rack management ability, and it can monitor and adjust parameters such as system temperature. It can realize hot backup of the system, making the system with high reliability and high transmission bandwidth.

Key Technologies and Application of Automatic Control System for Wide Stainless Steel Hot Strip Rolling Line

Wide stainless steel hot strip line integrated with mechanical electric hydraulic equipments is a complicated large system. Automatic control system is very important for improving mill efficiency and products quality. The new equipments and technology are introduced. The characteristics of hot strip line and its requests for automation, the ideas of control system design, system structure and configuration are explained in detail. Multilevel system, 1000M high speed fabric Ethernet between levels, 640M high speed global data memory network between controllers, high speed Profibus_DP network between controller and equipments, hot machine backup strategy of L2,Tri-cyclic fabric Ethernet redundancy of L1 and other innovative design ideas,and L2 main mathematic models, L1 key control models are all applied in the system. The design ideas of this paper and integrated automatic control system has been applied on several stainless steel hot strip lines.

LCA of a solar heating and cooling system equipped with a small water–ammonia absorption chiller

The development of renewable energy technologies is a critical tool for reducing climate change and the reliance on fossil fuels. However, renewable energy technologies cannot be considered totally clean because they require energy consumption and have environmental impacts that cannot be neglected during their life cycle.In this paper, the life cycle assessment methodology was applied to assess resource use and other environmental burdens related to the entire life-cycle steps of a solar cooling plant. The investigated system works with an absorption chiller assisted by a solar plant. Two back-up configurations (hot back-up and cold back-up) were examined in two localities: Palermo (southern Italy) and Zurich (Switzerland).The benefits in terms of primary energy savings and greenhouse gases emission reduction were demonstrated by comparing the use of this innovative plant in substitution of a conventional one.Energy and CO2eq emission payback times and the energy return ratio of the system were calculated. For all the analysed configurations they ranged from 4 to 6years.A sensitivity analysis related to the calculation of the energy payback time was carried out to assess the influence of various system performance parameters on the payback index.The analysis stressed the following:–LCA of renewable energy technologies has to include a detailed analysis of the use phase to assess the benefits that arise from the energy produced by the system during its useful life and to obtain reliable and high-quality LCA results.–The use phase is responsible of about 70–90% of the energetic and environmental impacts of the plant life cycle.–The innovative plant has a lower environmental impact than the conventional plant.–The advantages of renewable energy technologies strongly depend on the climate of the installation site.

Research on Error-Tolerant Model of Master Control Computer for Electronic Automation System

The power system operates safely and stably depends on the reliable operation of electric automation system of which the master control computer is the core. To improve the reliability,security and real-time performance of the master control computer, the error-tolerant model of master control computer based on replication technology for electronic automation system is built and the implementing method of model is introduced in great detail. For the defects of dual-computer hot backup system and on the basis of three-machine voting system, the error-tolerant model of master control computer designed in this paper makes some improvements in system structure and voting algorithm ,so as to provide a reference for the construction of electronic automation system in the “strong” and "self-healing" smart grid.

Optimal internal pricing and backup capacity of computer systems subject to breakdowns

In a recent survey computers were found to break down nine times per year in the average company and computer downtime cost U.S. business $4 billion in 1991. The existing literature that combines pricing and queuing analysis of a shared service facility does not explicitly consider the failures of computer systems. The objective of this paper is to examine the impact of computer breakdowns on various aspects of the pricing and capacity decisions. It also examines the issue whether to acquire backup capacity when the computer system is in repair. The results of this paper show that computer breakdowns have significant impact on various aspects of concern. In general, computer breakdowns increase the expected time of jobs in the system, thus discouraging the submission of low-value jobs. Less computer capacity is needed to service the jobs with higher values compared to the case where a computer works all the time. The utilization ratio is lower in view of computer breakdowns. The firm, faced with computer breakdowns, has to increase the price of computer service and the increase in price is significant. Secondly, the findings suggest that it is imperative to acquire backup capacity when computing is critical to the firm in terms of high delay cost of jobs. The research results support the “hot backup” strategy, a common industry practice to operate in parallel two computers with the same capacity. Finally, the firm should charge users the total marginal capacity costs of the firm's computer as well as the backup.

Voting Software for Fault-Tolerant Aircraft Flight Control Systems

An intelligent and robust voting service is proposed. The novel voting service, is capable of forming a consensus based on performance of redundant applications in the value, time and reliability domains.The voter is distributed using a hot backup approach to ensure timely recovery in the event of voter failure. Specification diversity is advocated in order to improve upon the effectiveness of design diversity. The voter is designed to be a system building block, embedded in a framework of design tools which will allow the developer to express control concepts, such as deadlines, priorities, re-plication and voting.

The EIC Control System and Mathematical Models for a Large Blast Furnace

This paper introduces the configuration and features of the EIC Electric, Instrumentation, Computer) control system of a large modern blast furnace, as well as the content of the blast furnace mathematical models. It also provides their execution effect. The blast furnace EIC system is a two level automatic control system that consists of three parts:Process Computer (PROCOM).Distributed Control System (DCS) which belongs to instrumentation section, and Programmable Logic Controller (PLC) which belongs to electric control section. The PROCOM is a dual hot backup system.One works on line, the other in hot backup mode. The system can detect faults automatically and switch over automatically. The DCS consists of 9 dual field control section.3 operations with CRT's.3 consoles with CRT's, 2 gateways for communication with process computer and dual high-speed communication bus. The DCS implements two sorts of functions, operating, monitoring, management and control, as well as data acquisition. The electric control system is also a multi-level distributed system including 16 PLCs of various kinds, used for job control, job management and communication with PROCOM respectively. There are 8 blast furnace mathematical models grouped in two parts:1 one-line control algorithm models and 4 off-line algorithm models.