LEADER 03162nam 2200697Ia 450 001 9910970326703321 005 20200520144314.0 010 $a9786612966583 010 $a9781282966581 010 $a1282966588 010 $a9780821386750 010 $a0821386751 024 7 $a10.1596/978-0-8213-8672-9 035 $a(CKB)2560000000055107 035 $a(EBL)635551 035 $a(OCoLC)704434211 035 $a(SSID)ssj0000472975 035 $a(PQKBManifestationID)11323270 035 $a(PQKBTitleCode)TC0000472975 035 $a(PQKBWorkID)10436698 035 $a(PQKB)11120076 035 $a(MiAaPQ)EBC635551 035 $a(Au-PeEL)EBL635551 035 $a(CaPaEBR)ebr10440507 035 $a(CaONFJC)MIL296658 035 $a(The World Bank)ocn689858608 035 $a(US-djbf)16566043 035 $a(Perlego)1484085 035 $a(EXLCZ)992560000000055107 100 $a20101203d2011 uf 0 101 0 $aeng 135 $aurcn||||||||| 181 $ctxt$2rdacontent 182 $cc$2rdamedia 183 $acr$2rdacarrier 200 10$aScience, technology, and innovation in Uganda $erecommendations for policy and action /$fCaroline S. Wagner ... [et al.] 205 $a1st ed. 210 $aWashington, D.C. $cWorld Bank$dc2011 215 $axxi, 105 pages $cillustrations ;$d26 cm 225 0 $aWorld Bank study 300 $aDescription based upon print version of record. 311 08$a9780821386729 311 08$a0821386727 320 $aIncludes bibliographical references. 327 $aCover; Title Page; Copyright; Contents; Acronyms and Abbreviations; Acknowledgments; Executive Summary; This Report's Purpose; 1. Science, Technology, and Innovation Strategies and Actors in Uganda; 2. Policy Recommendations; Annex 1. Science and Technology in Uganda; Annex 2. Agroindustry: Oilseed Sector Case Study; Annex 3. Health: Ethnobotany Case Study; Annex 4. Energy Case Study; Annex 5. Transport and Logistics Case Study; References; Back Cover 330 $aScience, Technology and Innovation in Uganda is part of the World Bank Studies series. These papers are published to communicate the results of the Bank's ongoing research and to stimulate public discussion.This study presents a unique methodology to view science, technology and innovation (STI) in developing countries. The study provides a set of cases studies drawn from a diverse range of experiences across the Ugandan private sector and offers concrete policy recommendations on how to support broader development of STI in Uganda. The study finds that of all the STI challenges facing firms, 410 0$aWorld Bank e-Library. 410 0$aWorld Bank study. 606 $aScience and state$zUganda$vCase studies 606 $aTechnology and state$zUganda$vCase studies 615 0$aScience and state 615 0$aTechnology and state 676 $a338.96761/06 701 $aWagner$b Caroline S$0989586 801 0$bMiAaPQ 801 1$bMiAaPQ 801 2$bMiAaPQ 906 $aBOOK 912 $a9910970326703321 996 $aScience, technology, and innovation in Uganda$94353820 997 $aUNINA LEADER 11204nam 22006013 450 001 9911006701203321 005 20231110220843.0 010 $a1-83724-570-3 010 $a1-5231-4232-4 010 $a1-83953-271-8 035 $a(MiAaPQ)EBC6803682 035 $a(Au-PeEL)EBL6803682 035 $a(CKB)19410374900041 035 $a(OCoLC)1286431426 035 $a(NjHacI)9919410374900041 035 $a(BIP)080795919 035 $a(MiAaPQ)EBC32265447 035 $a(Au-PeEL)EBL32265447 035 $a(OCoLC)1495015717 035 $a(EXLCZ)9919410374900041 100 $a20211117d2022 uy 0 101 0 $aeng 135 $aurcnu|||||||| 181 $ctxt$2rdacontent 182 $cc$2rdamedia 183 $acr$2rdacarrier 200 10$aProtection of Electricity Distribution Networks 205 $a4th ed. 210 1$aStevenage :$cInstitution of Engineering & Technology,$d2022. 210 4$dİ2022. 215 $a1 online resource (548 pages) 225 1 $aEnergy Engineering 311 08$a1-83953-270-X 327 $aIntro -- Title -- Copyright -- Contents -- About the authors -- Preface and acknowledgements -- Preface to second edition -- Preface to third edition -- 1 Introduction -- 1.1 General -- 1.2 Basic principles of electrical systems -- 1.3 Protection requirements -- 1.4 Protection zones -- 1.5 Primary and backup protection -- 1.5.1 Primary protection -- 1.5.2 Backup protection -- 1.6 Directional protection -- 1.7 Relay models -- 1.8 Adaptive protection -- 2 Calculation of short circuit currents -- 2.1 Modelling for short circuit current calculations -- 2.1.1 Effect of the system impedance -- 2.1.2 Effect of rotating machinery -- 2.1.3 Types of fault duty -- 2.1.4 Calculation of fault duty values -- 2.2 Fault calculation for symmetrical faults -- 2.3 Symmetrical components -- 2.3.1 Importance and construction of sequence networks -- 2.3.2 Calculation of asymmetrical faults using symmetrical components -- 2.3.3 Equivalent impedances for a power system -- 2.4 Supplying the current and voltage signals to protection systems -- 2.5 General considerations of fault currents from DERs -- 2.6 Analysis tools for short circuit current calculation -- 3 Classification and function of relays -- 3.1 Classification -- 3.1.1 Construction -- 3.1.2 Incoming signal -- 3.1.3 Function -- 3.1.4 International identification of electrical devices -- 3.2 Electromechanical relays -- 3.2.1 Attraction relays -- 3.2.2 Relays with moveable coils -- 3.2.3 Induction relays -- 3.3 Evolution of protection relays -- 3.4 Numerical protection -- 3.4.1 General -- 3.4.2 Characteristics of numerical relays -- 3.4.3 Typical architectures of numerical relays -- 3.4.4 Standard functions of numerical relays -- 3.5 Supplies to the relay circuits -- 4 Current and voltage transformers -- 4.1 Voltage transformers -- 4.1.1 Equivalent circuit -- 4.1.2 Errors -- 4.1.3 Burden -- 4.1.4 Selection of VTs. 327 $a4.1.5 Capacitor VTs -- 4.2 Current transformers -- 4.2.1 Equivalent circuit -- 4.2.2 Errors -- 4.2.3 AC saturation -- 4.2.4 Burden -- 4.2.5 Selection of CTs -- 4.2.6 Accuracy classes established by the ANSI standards -- 4.2.7 DC saturation -- 4.2.8 Precautions when working with CTs -- 5 Overcurrent protection -- 5.1 General -- 5.2 Types of overcurrent relay -- 5.2.1 Definite-current relays -- 5.2.2 Definite-time/current or definite-time relay -- 5.2.3 Inverse-time relays -- 5.3 Setting overcurrent relays -- 5.3.1 Setting instantaneous units -- 5.3.2 Coverage of instantaneous units protecting lines between substations -- 5.3.3 Setting the parameters of time-delay overcurrent relays -- 5.4 Constraints of relay coordination -- 5.4.1 Minimum short circuit levels -- 5.4.2 Thermal limits -- 5.4.3 Pickup values -- 5.5 Coordination across Dy transformers -- 5.5.1 Three-phase fault -- 5.5.2 Phase-to-phase fault -- 5.5.3 Phase-to-earth fault -- 5.6 Coordination with fuses -- 5.7 Coordination of negative-sequence units -- 5.8 Overcurrent relays with voltage control -- 5.9 Setting overcurrent relays using software techniques -- 5.10 Use of digital logic in numerical relaying -- 5.10.1 General -- 5.10.2 Principles of digital logic -- 5.10.3 Logic schemes -- 5.11 Adaptive protection with group settings change -- 5.12 Exercises -- 6 Fuses, reclosers and sectionalisers -- 6.1 Equipment -- 6.1.1 Reclosers -- 6.1.2 Sectionalisers -- 6.1.3 Fuses -- 6.2 Criteria for coordination of time/current devices in distribution systems -- 6.2.1 Fuse-fuse coordination -- 6.2.2 Recloser-fuse coordination -- 6.2.3 Recloser-recloser coordination -- 6.2.4 Recloser-relay coordination -- 6.2.5 Recloser-sectionaliser coordination -- 6.2.6 Recloser-sectionaliser-fuse coordination -- 6.2.7 Current-limiting fuses. 327 $a6.3 Criteria for coordination of time/current devices under automated feeder reconfiguration -- 6.4 Criteria for coordination of time/current devices with DG intermittent sources -- 7 Directional overcurrent relays -- 7.1 Construction -- 7.2 Principle of operation -- 7.3 Relay connections -- 7.3.1 30° Connection (0° AMT) -- 7.3.2 60° Connection (0° AMT) -- 7.3.3 90° Connection (30° AMT) -- 7.3.4 90 Connection (45 AMT) -- 7.4 Directional earth-fault relays -- 7.5 Coordination of instantaneous units -- 7.6 Setting of time-delay directional overcurrent units -- 7.6.1 Pickup setting -- 7.6.2 Time dial setting -- 7.7 Importance of the directional protection -- 7.8 Exercises -- 8 Differential protection -- 8.1 General -- 8.2 Classification of differential protection -- 8.3 Transformer differential protection -- 8.3.1 Basic considerations -- 8.3.2 Selection and connection of CTs -- 8.3.3 Inrush restraint -- 8.3.4 Percentage of winding protected by the differential relay during an earth fault -- 8.3.5 Determination of the slope -- 8.3.6 Distribution of fault current in power transformers -- 8.3.7 Dual slope setting -- 8.3.8 Overexcitation (V/Hz) -- 8.3.9 High setting (this defeats the differential protection) -- 8.4 Differential protection for generators and rotating machines -- 8.5 Line differential protection -- 8.6 Busbar differential protection -- 8.6.1 Differential system with multiple restraint -- 8.6.2 High-impedance differential system -- 8.7 Exercises -- 9 Distance protection -- 9.1 General -- 9.2 Types of distance relays -- 9.2.1 Impedance relay -- 9.2.2 Directional relay -- 9.2.3 Reactance relay -- 9.2.4 Mho relay -- 9.2.5 Completely polarised mho relay -- 9.2.6 Relays with lens characteristics -- 9.2.7 Relays with polygonal characteristics -- 9.2.8 Relays with combined characteristics -- 9.3 Setting the reach and operating time of distance relays. 327 $a9.4 The effect of infeeds on distance relays -- 9.5 The effect of arc resistance on distance protection -- 9.6 Residual compensation -- 9.7 Impedances seen by distance relays -- 9.7.1 Phase units -- 9.7.2 Earth-fault units -- 9.8 Power system oscillations -- 9.9 The effective cover of distance relays -- 9.10 Maximum load check -- 9.10.1 Mho relays -- 9.10.2 Relays with a polygonal characteristic -- 9.11 Drawing relay settings -- 9.11.1 Starting unit settings -- 9.11.2 Residual compensation constant setting -- 9.11.3 Time setting -- 9.11.4 Load check -- 9.11.5 Determination of the effective cover -- 9.12 Intertripping schemes -- 9.12.1 Underreach with direct tripping -- 9.12.2 Permissive underreach intertripping -- 9.12.3 Permissive overreach intertripping -- 9.13 Distance relays on series-compensated lines -- 9.14 Technical considerations of distance protection in tee circuits -- 9.14.1 Tee connection with infeeds at two terminals -- 9.14.2 Tee connection with infeeds at all three terminals -- 9.15 Use of distance relays for the detection of the loss of excitation in generators -- 9.16 Exercises -- 10 Protection of low-voltage systems -- 10.1 Protection devices -- 10.1.1 Overcurrent relays -- 10.1.2 Direct-acting devices in power breakers and MCCBs -- 10.1.3 Combined thermal relay contactor and fuse -- 10.1.4 MCCBs with numerical protection -- 10.2 Criteria for setting overcurrent protection devices associated with motors -- 10.2.1 Thermal relays -- 10.2.2 Low-voltage breakers -- 10.3 Arc flash -- 10.3.1 Arc flash calculation methods -- 10.3.2 Arc flash and approach boundary -- 10.3.3 Hazard study methodology -- 10.3.4 Electrode configurations -- 10.3.5 Selection of PPE -- 10.3.6 Arc thermal performance value -- 10.3.7 Energy break-open threshold -- 10.3.8 DC arc flash calculations -- 11 Industrial plant load shedding. 327 $a11.1 Power system operation after loss of generation -- 11.2 Design of an automatic load shedding system -- 11.2.1 Simple machine model -- 11.2.2 Considerations of implementing a load shedding system -- 11.3 Criteria for setting frequency relays -- 11.3.1 Operating times -- 11.3.2 Determination of the frequency variation -- 11.4 Example of calculating and setting frequency relays in an industrial plant -- 11.4.1 Calculation of overload -- 11.4.2 Load to be shed -- 11.4.3 Frequency levels -- 11.4.4 Load shedding stages -- 11.4.5 Determination of the frequency relay settings -- 11.4.6 Verification of operation -- 11.5 Load shedding using logic schemes -- 12 Protection schemes and substation design diagrams -- 12.1 Protection schemes -- 12.1.1 Generator protection -- 12.1.2 Motor protection -- 12.1.3 Transformer protection -- 12.1.4 Line protection -- 12.2 Types of substations -- 12.3 Substation design diagrams -- 12.3.1 Single-line diagrams -- 12.3.2 Substation layout diagrams -- 12.3.3 Diagrams of AC connections -- 12.3.4 Diagrams of DC connections -- 12.3.5 Wiring diagrams -- 12.3.6 Digital substations -- 12.3.7 Logic diagrams -- 12.3.8 Cabling lists -- 13 Communication networks for power systems automation -- 13.1 IEC 61850 overview -- 13.2 Standard documents and features of IEC 61850 -- 13.3 System Configuration Language -- 13.4 Challenges facing the testing of IEC 61850 devices -- 13.5 Configuration and verification of GOOSE messages -- 13.5.1 Configuration of the system -- 13.5.2 System verification test -- 13.6 Substation IT network -- 13.7 Process bus -- 14 Installation, testing and maintenance of protection systems -- 14.1 Installation of protection equipment -- 14.2 Testing protection schemes -- 14.2.1 Factory acceptance test -- 14.2.2 Commissioning tests -- 14.2.3 Maintenance test -- 14.2.4 Troubleshooting. 327 $a14.3 Commissioning numerical protection. 330 $aThis book provides an overview of most aspects of electrical protections. The emphasis is on distribution systems, but protection of generation and transmission systems are also treated. For this 4th edition, new topics are added, such as protection of renewable power plants and transient stability analysis. 410 0$aEnergy Engineering 606 $aElectric power distribution 615 0$aElectric power distribution. 676 $a621.319 700 $aGers$b Juan M$0745233 701 $aHolmes$b Edward$066164 801 0$bMiAaPQ 801 1$bMiAaPQ 801 2$bMiAaPQ 906 $aBOOK 912 $a9911006701203321 996 $aProtection of Electricity Distribution Networks$94390407 997 $aUNINA