Standby Power Supply Research Articles

Agro-Processing Value Chains Mapping and Technology Needs Assessment for Nyeri County, Kenya

A sectoral value chain mapping of the County Government of Nyeri, Kenya was initiated and implemented with regard to agro-processing of various forms of plant resources: food crops, textile/natural products, honey/animal feeds/ bio-energy/ICT, environment & biotechnology, essential oils, engineering services and Blue Economy. In this case, the following value-chain processes were assessed: Tea, Coffee; Oil crops; Banana & Dairy products with the support of service providers and prototypic environments. It also looked into value-addition practices and other cross-cutting factors. The cross-sectional study uncovered distinctions and issues including variability in the power supply, absence of Standard Operating Procedures (SOPs), minimal value addition, existence of counterfeit inputs, and unsuitable equipment. Recommendations include provision of standby power supply, provision of standard operating procedures, potential innovation in value addition, procurement of adequate equipment, and formulation of measures concerning genuine farm inputs. Therefore, by providing an enabling environment and putting into practice the strategies articulated in the study, sustainable agricultural-based growth and hence economic development in Nyeri County will be inevitably achieved under the Kenya Vision 2030.

Reliability and Sensitivity Analysis of Wireless Sensor Network Using a Continuous-Time Markov Process

A remarkably high growth has been observed in the uses of wireless sensor networks (WSNs), due to their momentous potential in various applications, namely the health sector, smart agriculture, safety systems, environmental monitoring, military operations, and many more. It is quite important that a WSN must have high reliability along with the least MTTF. This paper introduces a continuous-time Markov process, which is a special case of stochastic process, based on modeling of a wireless sensor network for analyzing the various reliability indices of the same. The modeling has been conducted by considering the different components, including the sensing unit, transceiver, microcontroller, power supply, standby power supply unit, and their failures/repairs, which may occur during their functioning. The study uncovered different important assessment parameters like reliability, components-wise reliability, MTTF, and sensitivity analysis. The critical components of a WSN are identified by incorporating the concept of sensitivity analysis. The outcomes emphasize that the proposed model will be ideal for understanding different reliability indices of WSNs and guiding researchers and potential users in developing a more robust wireless sensor network system.

POWER PROCESSING AND CONTROL UNIT OF THE EECTRIC PROPULSION SYSTEM

Abstract. The report presents the results of the development of the PPU-500, which is part of the SPS-500 electric propulsion system based on the ST-40 Hall thruster. PPU-500 contains all power supplies necessary for the operation of the propulsion system: discharge; electromagnet; cathode heater and keeper; power supplies for valves and heaters of the storage and feeding working substance, as well as a standby power supply that ensures the standby mode of PPU operation.The converter of the discharge power supply is built using a bridge topology with a phase-shifted output power control circuit. The remaining power supplies are built according to the topology of a step-down synchronous converter with current or voltage stabilization. The discharge power supply is a controlled power supply. The power supplies for the cathode heater and electromagnet current sources are. The accuracy of power supplies output parameters in not worse than 1.5%. The valves of the feeding system are controlled in order to stabilize the pressure in the receiver by periodically turning on/turning off the high- and low-pressure valves. For control the valves, signals taken from pressure sensors installed in the receiver are used. The PPU control unit ensures an accuracy of maintaining pressure in the receiver no worse than 2.5%. The control unit of the PPU is built using a microcontroller with an ARM core. It implements the functions of monitoring the condition of the program, restoring the program firmware if an integrity violation is detected, and the ability to remotely flash a new version. To communicate the SPS-500 with the on-board control system, a galvanically isolated CAN interface is used. It can be also the RS485/RS42 interface.During operation of the propulsion system, operating parameters are measured using multi-channel ADCs and DACs. The obtained data, on the one hand, is used to assess the current state of the propulsion system and control Hall thruster operating modes. On the other hand, they are transmitted as telemetry signals reflecting the current state of the SPS-500, operating mode and emerging emergency conditions of the equipment. PPU is possible to alternately control two thrusters. Solid-state switches are used to switch the corresponding power sources.Testing of the PPU-500 as part of the SPS-500 propulsion system with the ST-40 Hall thruster and a flight prototype of the working substance feeding system confirmed the technical solutions adopted. The operating efficiency of PPU-500 for the nominal operating mode of the propulsion system is 94%.

PLC Controlled Substation Standby Power Form the Input System

This paper introduces the application of Siemens S7-200 PLC in standby power supply. PLC collects the normal running state signal of the primary equipment, which is used as the starting condition and locking condition of the standby power supply automatically input. It realizes different functions through programming to adapt to different running modes. Through PLC and king view in the laboratory, I verified the operation mode. It is also increases the obstacles, enriches the content of the standby self-casting system, and realizes the simulation of the joint adjustment with PLC. It is more obvious to watch the practical application of the stand auto-casting and the diversification of its functions.

Review of Degradation Mechanism and Health Estimation Method of VRLA Battery Used for Standby Power Supply in Power System

As the backup power supply of power plants and substations, valve-regulated lead-acid (VRLA) batteries are the last safety guarantee for the safe and reliable operation of power systems, and the batteries’ status of health (SOH) directly affects the stability and safety of power system equipment. In recent years, serious safety accidents have often occurred due to aging and failure of VRLA batteries, so it is urgent to accurately evaluate the health status of batteries. Accurate estimation of battery SOH is conducive to real-time monitoring of single-battery health information, providing a reliable guarantee for fault diagnosis and improving the overall life and economic performance of the battery pack. In this paper, first, the floating charging operation characteristics and aging failure mechanism of a VRLA battery are summarized. Then, the definition and estimation methods of battery SOH are reviewed, including an experimental method, model method, data-driven method and fusion method. The advantages and disadvantages of various methods and their application conditions are analyzed. Finally, for a future big data power system backup power application scenario, the existing problems and development prospects of battery health state estimation are summarized and prospected.

Deep-implanting oxygen vacancy into VOx by alkylamine intercalation for life-oriented modular pouch supercapacitors

Aqueous supercapacitors have gained recent attention as a green energy storage option thanks to their low cost and high safety. However, to date, commercial applications of aqueous supercapacitors have not been realized. To this end, we try to promote the innovation in aqueous supercapacitors with copious V2O5. Admittedly, V2O5 materials are subject to poor energy storage performance, and thus remain second-tier candidates for supercapacitors. Herein, originating from alkylamine intercalation between V2O5 interlayer, a VOx with substantial deep-implanted oxygen vacancies within molecular interlayers is synthesized. The optimization of charge storage kinetics by the oxygen vacancies ensures a desirable specific capacitance of 1301F g−1 at 1 A/g, and even the initial specific capacitance of 81 % is retained at 10 A/g. Moreover, the long-cycle durability of 60,000 cycles without obvious attenuation is further guaranteed, which, to our knowledge, is superior to that of most reports. Further, an industrialized technique was applied to encapsulate the modular pouch device. As a verification, we demonstrate a modular pouch device with an energy density of 66.1 Wh kg−1 at 100.5 W kg−1 that can effectively withstand severe external stimuli during operation, really transferring the risk for the user. The arbitrary combination also practices the feasibility of the modular pouch device as a stand-by power supply for 3C products such as tablets and smartphones. We firmly believe that this innovative strategy will provide new impetus for the revolution of aqueous pouch supercapacitors.

A high performance vanadium oxide@molybdenophosphate composite for 2.2 V aqueous symmetric supercapacitors

Aqueous energy storage devices hold great promise for smart electric grids and electric vehicles due to their high ionic conductivity, high safety and low cost, but are often limited by electrode materials with rather low voltage window and sluggish mass transport kinetics through thicker electrode materials. Herein, we design a vanadium oxide@molybdenophosphate composite on oxygen-functionalized carbon substrate with wide potential range of −1.2 to 1.0 V vs. SCE and highly enhanced electron/ion delivery kinetics. The oxygen-functionalized 3D carbon scaffold can bind strongly with VOx through V-O-C bonding, leading to fast electron transport within electrodes and effective suppresses structural pulverization of oxides. The molybdenophosphate coating layer improves not only the electronic structure and electrical conductivity of VOx but also the charge storage performance of the composite. Due to those effective interactions, the vanadium oxide@molybdenophosphate composite exhibits an outstanding capacitance of 3,954 mF cm−2 and good rate capability. Realistically, the assembled symmetric supercapacitor device can operate stably with a voltage window of 2.2 V and delivers extraordinary energy density of 7.56 mWh cm−3, which is superior to most advanced supercapacitors. Arbitrary series connection also practices the feasibility of the device as a stand-by power supply for 3C products such as tablets. This innovative synergistic strategy opens up new opportunities for aqueous energy storage.

Design and Implementation of Programmable Logic Controller Based Automatic Transfer Switch

A PLC-based automatic transfer switch (ATS) may improve production in the industry efficiency and also the household power connection. It's an electrical switch that may be used to change the load when the main power is failing to supply electricity. Manually controlled transfer switches exist. In this scenario, a switch must be thrown by an operator to take manual control of the system. Some, on the other hand, are activated automatically when the main power source fails. When a major source of electricity is no longer functioning, power from a new or used generator can be either manually or automatically transferred when utilize a transfer switch for transferring control to the on-side application. Using a programmable logic controller (PLC), we describe the implementation and design of an automatic transfer switch (ATS). The primary function of a transfer switch is to divert electricity from the main grid to a standby power supply. Single-phase and three-phase circuit breakers, Siemens Logo PLC, relays, and indicator lights are used in this system. This portable and economic system would be helpful to every domestic, industrial, factory, and academic institution.

Design and Implementation of Programmable Logic Controller Based Automatic Transfer Switch

A PLC-based automatic transfer switch (ATS) may improve production in the industry efficiency and also the household power connection. It's an electrical switch that may be used to change the load when the main power is failing to supply electricity. Manually controlled transfer switches exist. In this scenario, a switch must be thrown by an operator to take manual control of the system. Some, on the other hand, are activated automatically when the main power source fails. When a major source of electricity is no longer functioning, power from a new or used generator can be either manually or automatically transferred when utilize a transfer switch for transferring control to the on- side application. Using a programmable logic controller (PLC), we describe the implementation and design of an automatic transfer switch (ATS). The primary function of a transfer switch is to divert electricity from the main grid to a standby power supply. Single-phase and three-phase circuit breakers, Siemens Logo PLC, relays, and indicator lights are used in this system. This portable and economic system would be helpful to every domestic, industrial, factory, and academic institution.

Notlicht-Sicherheitsbeleuchtung

Even Europe, as highly industrialised as it may be, is not extensively protected against power failures. The increased use of renewable energy sources and the associated fluctuations in supply mean that additional power supply issues may arise. As a result, a standby power supply is an absolute must, both in public spaces and at business premises. Central battery systems as emergency lighting systems offer secure protection in the event of a power supply failure, safely providing the required lighting level even when the main supply network is unavailable.

On High-Temperature Galvanic Elements of Stand­by Power Supply Sources based on Energy Condensed Systems

Study of ignition, combustion and electrochemical processes occurring in thin multilayer high-temperature galvanic elements derived from low-gas energy condensed systems was carried out. The research results made it possible to design a wide range of multifunctional standby power supply sources with improved performance, differing in application types, initiation modes, activation and operation times, overall dimensions and shape.

Quality and Reliability-Exploitation Modeling of Power Supply Systems

This article describes the issues related to the analysis of the reliability-exploitation of power supply systems in transport telematics devices (PSSs in TTDs). This paper characterizes solutions, which are applied in supply systems, and describes a PSS in a TTD from a main source and a standby one. This enables determining the dependencies denoting the probabilities of the system staying in full ability state, safety threat state, and safety unreliability state. A quality analysis of the PSS in TTD was conducted, and the indicator value of the supply continuity quality was evaluated. This indicator allows the demonstration of continuity quality of power supply (CQoPS) dependency on many quality dimensions, not just reliability. An example demonstrates the calculation of CQoPS factor for both the main and the standby power supply, employing three observations, each influencing the quality. The presented considerations in the field of quality and reliability-exploitation modeling of a PSS can be applied as well in other public utility facilities (including those classified as critical infrastructure). The character of functions performed by critical infrastructure facilities demands an operating continuity of these systems at an appropriate level. The co-first authors of the article once again address the issue of determining CQoPS factor, this time on the basis of modeling using mathematical evidence. TTD is an example in this article, because the presented methods can be used in any kind of system, especially in the power source of critical systems.

Use of a Graded Approach in Application of Management System Requirements for ETRR-2: Maintenance of the Standby Power Supply System as a Case Study

A process for establishing an Integrated Management System (IMS) for operation and maintenance of the ETRR-2 reactor is initiated. Development and application of the IMS consider the usage of a graded approach in order to commensurate the resources devoted to management system with the importance of an item/activity and the magnitude of the risks. Literatures have introduced different methods for the concept of graded approach which is very important in applying the management, safety and technical requirements. This paper provides an additional example for the methodology of applying such approach. It suggests a grading methodology and determines the considerations that need to be taken into account in grading the application of IMS requirements. The paper introduces a proposal for classification of items or activities in the ETRR-2 into four grades. Then gives a grading example of specific controls for maintenance of structures, systems and components (SSCs) in the plant and explains the management requirements appropriate for each grade. Finally, the approach is explained briefly using an application practice on the Standby Power Supply system of the plant as a case study.

Evaluation of the cost-benefit of standby retrial systems incorporating switching failure and general repair times

A robust power supply system with high availability and acceptable cost/benefit is essential for many service systems, such as communication networks and product manufacturing processes. This investigation is concerned with the evaluation of the cost-benefit of a standby retrial power supply system incorporating standby switching failure and general repair times, which is the first work on the comparative analysis of retrial availability systems incorporating switching failure and general repair times. Four different standby power supply retrial configurations are included and each configuration consists of a different number of primary and standby generators. The investigated system assumes that the time-to-failure and the time-to-repair of the primary and standby generators obey the exponential and general distributions, respectively. We also take that the switching over standbys may be failed into account. By using the supplementary variable technique, the explicit expressions of the steady-state availability for each configuration are derived. A comparative analysis of the availability and the cost-benefit ratio among four retrial systems is presented. We also rank the configurations based on the steady-state availability and cost-benefit ratio for two repair time distributions, Weibull and lognormal. The calculated numerical results can provide managers with decision reference for stable power supply system and cost reduction.

Power Management in Low-Power MCUs for Energy IoT Applications

In this paper, we identify and address the problems of designing effective power management schemes in low-power MCU design. Firstly, this paper proposes an application-based multipower domain architecture along with a variety of working modes to effectively realize the hierarchical control of power consumption. Furthermore, devices in energy IoT (eIoT) do not always work under the main power supply. When the main power supply is unavailable, the standby power supply (usually the battery) needs to maintain the operation and save the data. In order to ensure the complete isolation between these two power sources, it is always necessary to insert a diode in both select-conduction paths, respectively. In this paper, we built a stable and smooth power switching circuit into the chip, which can effectively avoid the diode voltage loss and reduce the BoM cost. In addition, in the sleep mode, considering the relaxed output voltage range and a limited driving capability requirement, an ultra-low-power standby power circuit is proposed, which can autonomously replace the internal LDO when in sleep, further reducing the sleep power consumption under the main power supply. Fabricated in a standard 0.11 μm CMOS process, our comparative analysis demonstrates substantial reduction in power consumption from 1 μA to 0.1 μA.

Power Control Framework for Green Data Centers

In recent years, renewable energy, such as wind and photovoltaic electric power has been increasingly integrated into data center power provisioning systems to address high energy consumption of data centers. However, in reality, the intermittency and randomness of renewable energy (power supply fluctuation) is detrimental to the reliable operation of sophisticated IT equipment in those so-called green data centers. In this article, we address the problem of data center power regulation explicitly taking into account the unreliability and instability of renewable energy sources. To this extent, we design a novel data center power control framework that smoothens the power fluctuation and instability of renewable energy sources. The core of our framework is two power regulation optimization algorithms. In particular, a server workload scheduling algorithm deals with high frequency fluctuations while an Uninterruptable Power Supply (UPS) power regulation algorithm handles low frequency and large extent power fluctuations. These algorithms are also designed to satisfy service level agreement (SLA) and standby power supply capacity. We have conducted an extensive evaluation study using trace data of a real data center of 30000-node cluster with 50 x 250 UPS battery groups and 24-hour power generation data from real wind farm and photovoltaic power station. The experimental results show our framework effectively smoothens fluctuations of data center power supply, more effective use of renewable energy, and extend the UPS batteries’ lives to reduce the skyrocketed data center operating expenses.

Fast motor bus transfer impact analysis in industrial plants, a dynamic perspective

One approach to deliver a dependable electrical power supply is fast bus transfer (FBT). In this method, electrical power of equipment is supplied through two sources and if the power to the main source is interrupted, the system will switch to the standby power supply. To make this process fast enough in order to avoid any interruption, it is necessary to use special equipment. Industry standards have defined many criteria to protect motors from transient dynamic forces, which may be induced during fast bus transfers, however since the introduction of these standards, many researchers have doubted their effectiveness for protecting motors, therefore new researches have been conducted to validate the functionality of these standards. In this paper, different aspects of FBT are analyzed, but the focus of this paper is dynamic analysis and its impact on motor's lifetime. Different influential factors in a successful FBT are analyzed and new recommendations are made.

An autonomous micro-generation site using alternative/autonomous sources of electric energy

Introduction: the article deals with development and implementation of an autonomous, scalable and flexible-capacity micro-generation site representing a combination of various alternative sources of electric energy (up to 30 kW). The co-authors offer a solution for an autonomous micro-generation site: a prototype of a modular platform for a hybrid power plant (MPHP), which enables the use of solar and wind energies, capacitors, as well as an autonomous standby power supply unit having an internal combustion engine. The basic idea underlying the concept of a modular platform and the module combination method are substantiated. Power supply patterns that comprise MPHP are provided. Testing results, as well as the economic efficiency of a system operating in a decentralized energy supply environment are presented in the article.Methods: the study is based on the analysis of strengths, weaknesses and features of existing energy systems using alternative/autonomous sources of electric energy with a view to the extension of capabilities and capacity by means of connecting new generating sources.Findings and discussion: the results of development of an autonomous micro-generation site are presented; a prototype of a modular platform for a hybrid power plant (MPHP) is manufactured.Conclusion: the modular platform of a hybrid power plant enables to combine different types of electric energy sources and retain effective control over operating modes, thus improving the energy supply reliability and saving organic fuel consumed for the generation of 1 kWh of electricity.

Design of Power Supply Package for Electricity Sales Companies Considering User Side Energy Storage Configuration

With the deepening of the reform of the power system, electricity sales companies are required to explore new business models and provide multi-faceted marketing programs for users. At the same time, with the reduction of energy storage (ES) costs and the gradual maturity of technology, user side ES, especially Battery ES, has become an effective means for enhancing users’ power supply reliability and reducing electricity bills. Battery ES, as the standby power supply, has a vast user side application. The configuration of ES can help users to ameliorate power quality and reduce electricity cost. It is a critical strategy for electricity sales companies to improve their competitiveness as well. Firstly, this paper analyzes the user side ES and introduces the user side ES development status and relevant policies. Then, we establish an ES configuration optimization model based on the cost–benefit system. To determine the optimal ES capacity of the system’s storage capacity, non-dominated sorting genetic algorithm with elite strategy (NSGA-II) is used as the method solving model. Finally, according to the cost-effectiveness of ES and the period of a contract signed by users, a price package with ES configuration is designed for users to choose.

A Hardware and Software Complex for Remote Monitoring of a High-Voltage Line Arrester under Operating Voltage

A hardware and software complex for remote monitoring of high-voltage line arresters (HVLAs) under operating voltage has been developed. The complex is a two-level distributed system with autonomous monitoring points. The main functional units of the complex are a block of current sensors, a registration and communication device, a self-contained power supply, a receiving base station, and an automated workplace (AWP). Apart from the total leakage current and number of operations, the complex registers the amplitude and duration of the HVLA lightning pulse. These parameters may be used for the assessment of the HVLA residual resources and making a decision as to the feasibility of its further operation. An optical sensor on the basis of a bismuth silicate crystal is used as a sensor of an impulse current; its operating principle is based on the Faraday linear magnetooptic effect. The advantage of the bismuth silicate crystal is the feasibility of the noncontact measurement of the pulse magnetic field strength, high temperature stability and high noise immunity. The standard of the wireless LoRa communication was selected for the transmission of information; its advantage is a high noise immunity, larger range of radio signal transmission (up to 10 km), low energy consumption, and high penetrating capacity penetrability. A solar battery with a standby power supply—a rechargeable battery—was selected as the self-contained power supply. Program modules for receiving and transmission of information and AWP were developed. The hardware and software system allow preventing the emergency situations on the high-voltage line, planning more service and repair operations more effectively and efficiently, and starting the operation of HVLAs based on technical conditions.