- Email: [email protected]
03321 A compact CO selective oxidation reactor for solid polymer fuel cell powered vehicle application
06 Nectricalpower supply and utilizabon (scientific, technical)
the system temperature is above 1900 C; under an oxidizing mode this temperature is 145O’C. For plutonium, the thermodynamically preferred solid-phase compound is PuO:(s) up to about 1500°C under either a reducing or an oxidtzing mode. As the temperature increases, the compound will vaporrre mainly rnto Its vnpour phase, i.e. PuO*(g), up to about 2000°C. Above thts temperature, the system contains only vapourphase compounds. In addition to equilibrium composition, the effective vapour pressure and the fraction m vapour phase for the two metals have also been evaluated. The existence of chlorine has not been found to affect the simulation results significantly. The simulation results have been compared with those generated from the HSC programme and the results have indicated that the HSC programme contains inappropriate thermodynamic data for uranium and plutonium simulations.
Economics,
policy, supplies,
forecasts
00103310 1999 load factors analysed by NSSS vendors Knox, R. NIX/ EIIX_In/.. 2000. 45, (551) 26-27. This article analyses the four main types of reactors and those vendors that have sold four or more of each respective type. The load factor averages, total reactor years of operation and total energy use is just some of the data presented about the nuclear reactors in this paper.
00103311 A mature and capable industry Price, M. Nncl. & In/.. 2000. 45, (551), 2X-31. Delegates to transport m the nuclear industry had been informed of the problems of surface contamination of large spent fuel transport flasks, and turned their attention to new revisions of transport regulations.
00/03312 A pattern-matching model for operator cognitive behaviors during accident conditions at a nuclear power plant Jo”, H. M. c, rrl. Annrris ~~f’Nuc/. Erzrrg~. 2000, 27, (IO), 935-948. This paper proposes an integrated framework of modelling human operator behaviours during accident conditions at a nuclear power plant. The operator model consists of the model for cognitive process and the memory system that supports the cognitrve process. As for cognitive process, using frame and membership function, the state-oriented behaviour, i.e. patternmatching is explicitly implemented, which is identified as the dominant cognitive process of an operator responding to an accident sequence. A computer code, OPEC, is formulated to specifically incorporate the pattern-matching along with logical reasoning into the integrated framework of modelling human cognitive behaviours. As a case study, the code is actually applied to an SCTR accident sequence in order to obtain the simulated behavinurs of a responding operator.
00103313 NEI honors Alliant, Southern for innovations NW/ NF\I..V,2000. 43. (7). 20-27. Alliant Energy and Southern Nuclear Operating Company shared in receiving the Nuclear Energy Institute’s top Industry practice (TIP) Award for developing new safety-focused inspection and testing programmes for their Dane Arnold and Farley nuclear power plants, respectively.
00103314 Parliament rejects Minatom’s waste plans Perera, J. and Fell, N. Vrrcl. Eng. Ifrr, 2000. 45, (551). 16-17. Russia’s nuclear energy ministry sees a potentially lucrative business opportunity in importing foreign spent fuel for storage or reprocessing. However, Minatom‘s plans have met opposition from the Federation Council.
00103315 The human performance improvement program at Duke Power nuclear stations Shiel, T. Vrrclcur Ncn~. 2000, 43. (6), 30-34. A conscientious effort to get at the root of human performance short-falls has led to the development of a system that has taken Duke Power’s McCuire nuclear station from an average performer five years ago to one of the more effictent, reliable stations m the country.
00103316 The nuclear industry learns its market value Davies, E. Nucl. En!: Inr.. 2000, 45. (551). 18-23 This paper revtcws the main events that have occurred throughout world in the nuclear industry since June 1999.
the
00103317 The U.S. nuclear plant market: the search for value Donoghue. D. rr (I/ Nrrci ,Ycn~.s.2000. 43, (7). 32 -36. Interest in acquiring US nuclear power plants has Increased, after slow start, compared to the acqursition of fossil-based capacity.
06
ELECTRICAL POWER SUPPLY AND UTILIZATION Scientific,
technical
00103318 Fuel reforming and electrical performance studies in intermediate temperature ceria-gadolinia-based SOFCs Livermore, S. J. A. er
Fuel and Energy Abstracts
November 2000
373
06 Nectrical
power
supply and utilization (scientific, technical)
1s4 Ii&es and experimental results show that the selective oxidation unit can reduce the CO from up to 2% to less than 15 ppm and is suitable for a vehicle fuel cell power plant of 20 kW,. 00103322 A comparison of hydrogen, methanol and gasoline as fuels for fuel cell Ogden, J. M. rr al. J. Power Sources, 1999, 79. (2). 143-168. As a fuel, hydrogen is required in all fuel cells currently being developed for near term use in electric vehicles. The gas can be stored directly or produced onboard the vehicle by reforming methanol or hydrocarbon fuels derived from crude oil (e.g. gasoline, diesel, or middle distillates). The vehicle design is simpler with direct hydrogen storage, but requires developing a more complex refuelling infrastructure. In this paper, modelling results are presented comparing three leading options for fuel storage onboard fuel cell vehicles: (a) compressed gas hydrogen storage, (b) onboard steam reforming of methanol, (c) onboard partial oxidation (POX) of hydrocarbon fuels derived from crude oil. A fuel cell vehicle model has been developed, as well as detailed models of onboard fuel processors. This allows an examination of the vehicle performance, fuel economy, weight, and cost for various vehicle parameters, fuel storage choices and driving cycles. The infrastructure requirements are also compared for gaseous including the added costs of fuel hydrogen, methanol and gasoline, production, storage, distribution and refuelling stations. The delivered fuel cost, total lifecycle cost of transportation, and capital cost of infrastructure development are estimated for each alternative. Possible fuel strategies leading to the commercialization of fuel cell vehicles are discussed, considering both vehicle and infrastructure issues. 00103323 A dynamic simulation model for power plants with atmospheric and pressurized circulating fluidized bed combustion - interactions of plant components and design studies Glasmacher-Remberg, C. and Fett, F. N. Proc. Inr. Cor~f. Fluid. Berl Comhus,., 1999, 1429-1452. This paper presents a dynamic simulation model for power plants with atmospheric circulating fluidized bed combustion (ACFBC) and pressurized circulating fluidized bed combustion (PCFBC) consisting of comprehensive sub-models for the subsystems gas turbine, circulating fluidized bed combustor and water/steam cycle. Apart from the investigation of the complete power plant, the simulation programme enables the analysis of the three mentioned subsystems separately. Each subsystem is described by a set of unsteady-state differential and algebraic equations solved by an implicit Euler-method using a modified Newton-Raphson method. With the aid of the dynamic simulation programme for a selected power plant, the effect of changes in plant operation will be examined for full and part load as well as the transient response of the system due to the operation carried out. Emphasis is laid on the characterization of the interactions between the subsystems. The dynamic simulation programme can be used for design studies and it is investigated how the operation characteristics of the example plant are influenced by changes in the plant design. 00/03324 A low-temperature electrolyte for lithium and lithiumion batteries Plichta, E. _I.and Behl, W. K. Journal o/Power Sources, 2000, 88, (2), 192196. An electrolyte consisting of 1 M solution of lithium hexafluorophosphate in 1:1:1 ethylene carbonate(dimethyl carbonate(DMC)-ethyl methyl carbonate(EMC) is proposed for low temperature applications of lithium and lithium-ion cells. The new electrolyte has good conductivity and electrochemical stability. Lithium and lithium-ion cells using the new electrolyte were found to be operable at temperatures down to -40”. The paper also reports on the electrochemical stability of aluminium metal, which is used as a substrate for the positive electrodes in lithium-ion cells, in the new electrolyte. 00103325 A new genetic algorithm for preventive unit maintenance scheduling of power systems Wang, Y. and Handschin, E. E/w. Power md Energy Sysr.. 2OOU).22. (5). 343-348. Based on the essence of genetic algorithms (GAS), this paper presents a more efficient GA for unit maintenance scheduling of power systems. This new GA improves GA computation performance by adopting a codespecific and constraint-transparent integral coding method. To form a more promising convergence sequence and to refrain from the occurrence of unfeasible solutions, in this new GA, GA operators are redesigned according to the specific characteristics of the problem to be solved. Comparisons of this new GA with a traditional binary GA are also discussed. 00103326 A new immobilized-alkali Hz/O2 fuel cell Rowshanzamir, S. and Kazemeini, M. Journcrl of Power Sources, 2000, 88, (2), 262-268. A new kind of fuel cell has been designed and constructed. This is called an immobilized-alkali H2/0z single fuel cell, where the electrolyte is embedded in a porous matrix. Also, a different approach to electrode production for alkaline fuel cells is considered. Electrodes are single-layer, Teflon-bonded, gas-diffusion type and prepared by the pressing technique. Details of the preparation for these electrodes and their physical characterization by means of BET analysis, porosimetry, scanning electron microscopy and
374
Fuel and Energy Abstracts
November 2000
electrochemical evaluation (including Tafel and potentiostaic studies) are reported. The voltage-current behaviour of the fuel cell is determined under different operational conditions. The efficiency is 66% at a temperature of 25°C and a pressure of 1 bar. 00/03327 A new load frequency variable structure controller using genetic algorithms Al-Hamouz, Z. M. and Al-Duwaish, H. N. Eleclric Power Sys~rms Research, 2000, 55. (I), l-6. In this paper, a selection of the variable structure controller (VSC) feedback gains by genetic algorithms (GA) is presented contrary to the trial and error selection of the variable structure feedback gains reported in the literature. This is considered as one of the main underlying problems associated with VSC. The proposed method provides an optimal and systematic way of feedback gains selection in the VSC. To test the effectiveness of the new selection method, the proposed design has been applied to the load frequency problem of a single area power system. The system performance against step load variations has been simulated and compared to some previous methods. Simulation results show that not only the dynamic system performance has been improved, but also the control effort is dramatically reduced. 00103328 A study of carbon deposition on fuel cell power plants - morphology of deposited carbon and catalytic metal in carbon deposition reactions on stainless steel Sone, Y. et ul. Journd qf Power Sources, 2000, 86, (l-2), 334-339. Carbon deposited on SUS304 stainless steel (18Cr 8Ni) has been observed by two different methods. One method was field emission transmission electron microscopy (FE-TEM), with developed preparation for in situ observation of a cross-section of the deposited carbon from the base (SUS) to the top. The other method was X-ray photoelectron spectroscopy (XPS), obtaining composition-depth profiles by argon ion sputtering. Carbon was deposited on SUS304, 550°C 1 atm, HaICOICOz = 75/15/10, after drained the steam-reformed natural gas composition. One result from FE-TEM identified the major form of deposited carbon was tubular in shape with a variety of diameters, ranging from approximately 7 to 100 nm. Some tubes contained metallic particles which were about 20 nm in size at their tips. Therefore, it can be established that the carbon deposition mechanism is similar to that reported for metals such its iron, nickel, and that the deposited carbon can grow after the SUS surface is covered with deposits under the above conditions. Observations from EDX attached to FE-TEM also determined that most of the particles consisted of iron and from XPS, that the content of iron on the surface of the reaction plate was lower than on the unreacted sample. This indicates that carbon deposition oil stainless steel was influenced by iron rather than nickel and chromium. 00103329 A study of SOFC-PEM hybrid systems Dicks, A. L. er al. Journul of Power Sources, 2000, 86. (l-2), 501-506. The benefits of a system combining high- and low-temperature fuel cell types have been assessed using computer predictions. A high-temperature solid oxide fuel cell (SOFC) may be used to produce electricity and carry out fuel reforming simultaneously. The exhaust stream from an SOFC can be processed by shift reactors and supplied to a low-temperature polymer electrolyte membrane (PEM) cell. The overall efficiency predicted for the hybrid system is shown to be significantly better than a Reformer-PEM system or an SOFC-only system. Approximate capital and running cost estimates also show significant benefits compared to the other two systems, 00/03330 AC chopper voltage controller-fed single-phase induction motor employing symmetrical PWM control technique Ahmed, N. A. Electric Power Systems Research, 2000, 55, (I), 15-25. Due to the growing demand in improving the performance of motor drives, there is an increasing need to improve the quality and reliability of the drive circuit. AC-to-AC converter schemes using pulse width modulation (PWM) are proved to achieve substantial advantages over conventional linecommutated AC controllers. With the increasing availability and power capability of MOSFET’s and IGBT’s switches, PWM converters can efficiently and economically be used in low and medium power applications, However, such controllers have been applied only to control the voltage of passive R-L loads. In this paper, the performance characteristics of a symmetrical PWM AC chopper controller-fed single-phase induction motor drive are evaluated. The developed analysis is verified experimentally using a mathematical model. 00103331 Advanced design of valve-regulated lead-acid battery for hybrid electric vehicles Lam, L. T. el al. Journul of Power Sources, 2000, 88, (I), 92-97. A novel design of lead-acid battery has been developed for use in hybrid electric vehicles (HEVs). The battery has current take-offs at both ends of each of the positive and negative plates. This feature markedly reduces battery operating temperatures, improves battery capacity, and extends cycle-life under HEV duty. The battery also performs well under partialstate-of-charge (PSoC)/fast-charge, electric-vehicle operation. The improvements in performance are attributed to more uniform utilization of the plate active-materials. The battery, combined with an internalcombustion engine and a new type of super-capacitor, will be used to power an HEV, which is being designed and constructed by an Australian industry-government consortium.
the system temperature is above 1900 C; under an oxidizing mode this temperature is 145O’C. For plutonium, the thermodynamically preferred solid-phase compound is PuO:(s) up to about 1500°C under either a reducing or an oxidtzing mode. As the temperature increases, the compound will vaporrre mainly rnto Its vnpour phase, i.e. PuO*(g), up to about 2000°C. Above thts temperature, the system contains only vapourphase compounds. In addition to equilibrium composition, the effective vapour pressure and the fraction m vapour phase for the two metals have also been evaluated. The existence of chlorine has not been found to affect the simulation results significantly. The simulation results have been compared with those generated from the HSC programme and the results have indicated that the HSC programme contains inappropriate thermodynamic data for uranium and plutonium simulations.
Economics,
policy, supplies,
forecasts
00103310 1999 load factors analysed by NSSS vendors Knox, R. NIX/ EIIX_In/.. 2000. 45, (551) 26-27. This article analyses the four main types of reactors and those vendors that have sold four or more of each respective type. The load factor averages, total reactor years of operation and total energy use is just some of the data presented about the nuclear reactors in this paper.
00103311 A mature and capable industry Price, M. Nncl. & In/.. 2000. 45, (551), 2X-31. Delegates to transport m the nuclear industry had been informed of the problems of surface contamination of large spent fuel transport flasks, and turned their attention to new revisions of transport regulations.
00/03312 A pattern-matching model for operator cognitive behaviors during accident conditions at a nuclear power plant Jo”, H. M. c, rrl. Annrris ~~f’Nuc/. Erzrrg~. 2000, 27, (IO), 935-948. This paper proposes an integrated framework of modelling human operator behaviours during accident conditions at a nuclear power plant. The operator model consists of the model for cognitive process and the memory system that supports the cognitrve process. As for cognitive process, using frame and membership function, the state-oriented behaviour, i.e. patternmatching is explicitly implemented, which is identified as the dominant cognitive process of an operator responding to an accident sequence. A computer code, OPEC, is formulated to specifically incorporate the pattern-matching along with logical reasoning into the integrated framework of modelling human cognitive behaviours. As a case study, the code is actually applied to an SCTR accident sequence in order to obtain the simulated behavinurs of a responding operator.
00103313 NEI honors Alliant, Southern for innovations NW/ NF\I..V,2000. 43. (7). 20-27. Alliant Energy and Southern Nuclear Operating Company shared in receiving the Nuclear Energy Institute’s top Industry practice (TIP) Award for developing new safety-focused inspection and testing programmes for their Dane Arnold and Farley nuclear power plants, respectively.
00103314 Parliament rejects Minatom’s waste plans Perera, J. and Fell, N. Vrrcl. Eng. Ifrr, 2000. 45, (551). 16-17. Russia’s nuclear energy ministry sees a potentially lucrative business opportunity in importing foreign spent fuel for storage or reprocessing. However, Minatom‘s plans have met opposition from the Federation Council.
00103315 The human performance improvement program at Duke Power nuclear stations Shiel, T. Vrrclcur Ncn~. 2000, 43. (6), 30-34. A conscientious effort to get at the root of human performance short-falls has led to the development of a system that has taken Duke Power’s McCuire nuclear station from an average performer five years ago to one of the more effictent, reliable stations m the country.
00103316 The nuclear industry learns its market value Davies, E. Nucl. En!: Inr.. 2000, 45. (551). 18-23 This paper revtcws the main events that have occurred throughout world in the nuclear industry since June 1999.
the
00103317 The U.S. nuclear plant market: the search for value Donoghue. D. rr (I/ Nrrci ,Ycn~.s.2000. 43, (7). 32 -36. Interest in acquiring US nuclear power plants has Increased, after slow start, compared to the acqursition of fossil-based capacity.
06
ELECTRICAL POWER SUPPLY AND UTILIZATION Scientific,
technical
00103318 Fuel reforming and electrical performance studies in intermediate temperature ceria-gadolinia-based SOFCs Livermore, S. J. A. er
Fuel and Energy Abstracts
November 2000
373
06 Nectrical
power
supply and utilization (scientific, technical)
1s4 Ii&es and experimental results show that the selective oxidation unit can reduce the CO from up to 2% to less than 15 ppm and is suitable for a vehicle fuel cell power plant of 20 kW,. 00103322 A comparison of hydrogen, methanol and gasoline as fuels for fuel cell Ogden, J. M. rr al. J. Power Sources, 1999, 79. (2). 143-168. As a fuel, hydrogen is required in all fuel cells currently being developed for near term use in electric vehicles. The gas can be stored directly or produced onboard the vehicle by reforming methanol or hydrocarbon fuels derived from crude oil (e.g. gasoline, diesel, or middle distillates). The vehicle design is simpler with direct hydrogen storage, but requires developing a more complex refuelling infrastructure. In this paper, modelling results are presented comparing three leading options for fuel storage onboard fuel cell vehicles: (a) compressed gas hydrogen storage, (b) onboard steam reforming of methanol, (c) onboard partial oxidation (POX) of hydrocarbon fuels derived from crude oil. A fuel cell vehicle model has been developed, as well as detailed models of onboard fuel processors. This allows an examination of the vehicle performance, fuel economy, weight, and cost for various vehicle parameters, fuel storage choices and driving cycles. The infrastructure requirements are also compared for gaseous including the added costs of fuel hydrogen, methanol and gasoline, production, storage, distribution and refuelling stations. The delivered fuel cost, total lifecycle cost of transportation, and capital cost of infrastructure development are estimated for each alternative. Possible fuel strategies leading to the commercialization of fuel cell vehicles are discussed, considering both vehicle and infrastructure issues. 00103323 A dynamic simulation model for power plants with atmospheric and pressurized circulating fluidized bed combustion - interactions of plant components and design studies Glasmacher-Remberg, C. and Fett, F. N. Proc. Inr. Cor~f. Fluid. Berl Comhus,., 1999, 1429-1452. This paper presents a dynamic simulation model for power plants with atmospheric circulating fluidized bed combustion (ACFBC) and pressurized circulating fluidized bed combustion (PCFBC) consisting of comprehensive sub-models for the subsystems gas turbine, circulating fluidized bed combustor and water/steam cycle. Apart from the investigation of the complete power plant, the simulation programme enables the analysis of the three mentioned subsystems separately. Each subsystem is described by a set of unsteady-state differential and algebraic equations solved by an implicit Euler-method using a modified Newton-Raphson method. With the aid of the dynamic simulation programme for a selected power plant, the effect of changes in plant operation will be examined for full and part load as well as the transient response of the system due to the operation carried out. Emphasis is laid on the characterization of the interactions between the subsystems. The dynamic simulation programme can be used for design studies and it is investigated how the operation characteristics of the example plant are influenced by changes in the plant design. 00/03324 A low-temperature electrolyte for lithium and lithiumion batteries Plichta, E. _I.and Behl, W. K. Journal o/Power Sources, 2000, 88, (2), 192196. An electrolyte consisting of 1 M solution of lithium hexafluorophosphate in 1:1:1 ethylene carbonate(dimethyl carbonate(DMC)-ethyl methyl carbonate(EMC) is proposed for low temperature applications of lithium and lithium-ion cells. The new electrolyte has good conductivity and electrochemical stability. Lithium and lithium-ion cells using the new electrolyte were found to be operable at temperatures down to -40”. The paper also reports on the electrochemical stability of aluminium metal, which is used as a substrate for the positive electrodes in lithium-ion cells, in the new electrolyte. 00103325 A new genetic algorithm for preventive unit maintenance scheduling of power systems Wang, Y. and Handschin, E. E/w. Power md Energy Sysr.. 2OOU).22. (5). 343-348. Based on the essence of genetic algorithms (GAS), this paper presents a more efficient GA for unit maintenance scheduling of power systems. This new GA improves GA computation performance by adopting a codespecific and constraint-transparent integral coding method. To form a more promising convergence sequence and to refrain from the occurrence of unfeasible solutions, in this new GA, GA operators are redesigned according to the specific characteristics of the problem to be solved. Comparisons of this new GA with a traditional binary GA are also discussed. 00103326 A new immobilized-alkali Hz/O2 fuel cell Rowshanzamir, S. and Kazemeini, M. Journcrl of Power Sources, 2000, 88, (2), 262-268. A new kind of fuel cell has been designed and constructed. This is called an immobilized-alkali H2/0z single fuel cell, where the electrolyte is embedded in a porous matrix. Also, a different approach to electrode production for alkaline fuel cells is considered. Electrodes are single-layer, Teflon-bonded, gas-diffusion type and prepared by the pressing technique. Details of the preparation for these electrodes and their physical characterization by means of BET analysis, porosimetry, scanning electron microscopy and
374
Fuel and Energy Abstracts
November 2000
electrochemical evaluation (including Tafel and potentiostaic studies) are reported. The voltage-current behaviour of the fuel cell is determined under different operational conditions. The efficiency is 66% at a temperature of 25°C and a pressure of 1 bar. 00/03327 A new load frequency variable structure controller using genetic algorithms Al-Hamouz, Z. M. and Al-Duwaish, H. N. Eleclric Power Sys~rms Research, 2000, 55. (I), l-6. In this paper, a selection of the variable structure controller (VSC) feedback gains by genetic algorithms (GA) is presented contrary to the trial and error selection of the variable structure feedback gains reported in the literature. This is considered as one of the main underlying problems associated with VSC. The proposed method provides an optimal and systematic way of feedback gains selection in the VSC. To test the effectiveness of the new selection method, the proposed design has been applied to the load frequency problem of a single area power system. The system performance against step load variations has been simulated and compared to some previous methods. Simulation results show that not only the dynamic system performance has been improved, but also the control effort is dramatically reduced. 00103328 A study of carbon deposition on fuel cell power plants - morphology of deposited carbon and catalytic metal in carbon deposition reactions on stainless steel Sone, Y. et ul. Journd qf Power Sources, 2000, 86, (l-2), 334-339. Carbon deposited on SUS304 stainless steel (18Cr 8Ni) has been observed by two different methods. One method was field emission transmission electron microscopy (FE-TEM), with developed preparation for in situ observation of a cross-section of the deposited carbon from the base (SUS) to the top. The other method was X-ray photoelectron spectroscopy (XPS), obtaining composition-depth profiles by argon ion sputtering. Carbon was deposited on SUS304, 550°C 1 atm, HaICOICOz = 75/15/10, after drained the steam-reformed natural gas composition. One result from FE-TEM identified the major form of deposited carbon was tubular in shape with a variety of diameters, ranging from approximately 7 to 100 nm. Some tubes contained metallic particles which were about 20 nm in size at their tips. Therefore, it can be established that the carbon deposition mechanism is similar to that reported for metals such its iron, nickel, and that the deposited carbon can grow after the SUS surface is covered with deposits under the above conditions. Observations from EDX attached to FE-TEM also determined that most of the particles consisted of iron and from XPS, that the content of iron on the surface of the reaction plate was lower than on the unreacted sample. This indicates that carbon deposition oil stainless steel was influenced by iron rather than nickel and chromium. 00103329 A study of SOFC-PEM hybrid systems Dicks, A. L. er al. Journul of Power Sources, 2000, 86. (l-2), 501-506. The benefits of a system combining high- and low-temperature fuel cell types have been assessed using computer predictions. A high-temperature solid oxide fuel cell (SOFC) may be used to produce electricity and carry out fuel reforming simultaneously. The exhaust stream from an SOFC can be processed by shift reactors and supplied to a low-temperature polymer electrolyte membrane (PEM) cell. The overall efficiency predicted for the hybrid system is shown to be significantly better than a Reformer-PEM system or an SOFC-only system. Approximate capital and running cost estimates also show significant benefits compared to the other two systems, 00/03330 AC chopper voltage controller-fed single-phase induction motor employing symmetrical PWM control technique Ahmed, N. A. Electric Power Systems Research, 2000, 55, (I), 15-25. Due to the growing demand in improving the performance of motor drives, there is an increasing need to improve the quality and reliability of the drive circuit. AC-to-AC converter schemes using pulse width modulation (PWM) are proved to achieve substantial advantages over conventional linecommutated AC controllers. With the increasing availability and power capability of MOSFET’s and IGBT’s switches, PWM converters can efficiently and economically be used in low and medium power applications, However, such controllers have been applied only to control the voltage of passive R-L loads. In this paper, the performance characteristics of a symmetrical PWM AC chopper controller-fed single-phase induction motor drive are evaluated. The developed analysis is verified experimentally using a mathematical model. 00103331 Advanced design of valve-regulated lead-acid battery for hybrid electric vehicles Lam, L. T. el al. Journul of Power Sources, 2000, 88, (I), 92-97. A novel design of lead-acid battery has been developed for use in hybrid electric vehicles (HEVs). The battery has current take-offs at both ends of each of the positive and negative plates. This feature markedly reduces battery operating temperatures, improves battery capacity, and extends cycle-life under HEV duty. The battery also performs well under partialstate-of-charge (PSoC)/fast-charge, electric-vehicle operation. The improvements in performance are attributed to more uniform utilization of the plate active-materials. The battery, combined with an internalcombustion engine and a new type of super-capacitor, will be used to power an HEV, which is being designed and constructed by an Australian industry-government consortium.