Author Affiliation: University of Picardie; General Electric Co. Abstract: In recent years, marked improvement has been achieved in the design and manufacture of ...
What Stator Current Processing Based Technique To Use for Induction Motor Rotor Faults Diagnosis Benbouzid, M.E.H.; Kliman, G.B. Author Affiliation: University of Picardie; General Electric Co. Abstract: In recent years, marked improvement has been achieved in the design and manufacture of stator winding. However, motors driven by solid-state inverters undergo severe voltage stresses due to rapid switch-on and switch-off of semiconductor switches. Also, induction motors are required to operate in highly corrosive and dusty environments. Requirements such as these have spurred the development of vastly improved insulation material and treatment processes. But cage rotor design has undergone little change. As a result, rotor failures now account for a larger percentage of total induction motor failures. Broken cage bars and bearing deterioration are now the main cause of rotor failures. Moreover, with advances in digital technology over the last years, adequate data processing capability is now available on cost-effective hardware platforms to monitor motors for a variety of abnormalities on a real-time basis in addition to the normal motor protection functions. Such multifunction monitors are starting to displace the multiplicity of electromechanical devices commonly applied for many years. For such reasons, this paper is devoted to a comparison of signalprocessing-based techniques for the detection of broken bars and bearing deterioration in induction motors. Features of these techniques that are relevant to fault detection are presented. These features are then analyzed and compared to deduce the most appropriate technique for induction motor rotor fault detection. Keywords: Induction motor, rotor fault diagnosis, stator current. Preprint Order Number: PE-555EC (05-2002) Discussion Deadline: October 2002
Energy Development and Power Generation Energy Yield Simulations of Interconnected Solar PV Arrays Kaushika, N.D.; Gautam, N.K. Author Affiliation: Indian Institute of Technology. Abstract: The electrical characteristics of array interconnection schemes are investigated, using simulation models to find a configuration that is comparatively less susceptible to shadow problems and power degradation resulting from the aging of solar cells. Three configurations have been selected for comparison: simple series-parallel (SP) array, which has zero interconnection redundancy; total-cross-tied (TCT) array, which is obtained from the simple SP array by connecting ties across each row of junctions and which may be characterized as the scheme with the highest possible redundancy; and bridge-linked (BL) array, in which all cells are interconnected in bridge rectifier fashion. The explicit computer simulations for the energy yield and current-voltage distributions in the array are presented, which seem to favor cross-tied configurations (TCT and BL) in coping with the effects of mismatch losses. Keywords: Solar PV array, cross-tied array, solar interconnection schemes, energy yield, shadow problem. Preprint Order Number: PE-240EC (05-2002) Discussion Deadline: October 2002
Optimal Design of Power System Stabilizers Using Evolutionary Programming Abido, M.A.; Abdel-Magid, YL. Author Affiliation: King Fahd University of Petroleum and Minerals. Abstract: The optimal design of power system stabilizers (PSS) using the evolutionary programming (EP) optimization technique is presented. The proposed approach employs EP to search for optimal 62
settings of PSS parameters that shift the system eigenvalues associated with the electromechanical modes to the left in the s-plane. Incorporation of the EP algorithm in the design of PSSs significantly reduces the computational burden. The performance of the proposed PSSs under different disturbances, loading conditions, and system configurations is investigated for a multimachine power systems. The eigenvalue analysis and the nonlinear simulation results show the effectiveness and robustness of the proposed PSSs to damp out the local as well as the interarea modes of oscillations and work effectively over a wide range of loading conditions and system configurations. Keywords: PSS design, evolutionary programming, and dynamic stability. Preprint Order Number: PE-258EC (05-2002) Discussion Deadline: October 2002
Theoretical and Experimental Analyses of Photovoltaic Systems with Voltage and Current-Based Maximum Power Point Tracking Masoum, M.A.; Dehbonei, H.; Fuchs, E.F. Author Affiliation: Iran University of Science & Technology; Curtin University of Technology; University of Colorado. Abstract: Detailed theoretical and experimental analyses are presented for the comparison of two simple fast and reliable maximum power point tracking (MPPT) techniques for photovoltaic systems (PV): the voltage-based (VMPPT) and the current-based (CMPPT) approaches. A microprocessor-controlled tracker capable of online voltage and current measurements and programmed with both VMPPT and CMPPT algorithms is constructed. The load of the solar system is either a water pump or a resistance. Simulink facilities are used for simulation and modeling of the novel trackers. The main advantage of this new MPPT, as compared with present trackers, is the elimination of reference (dummy) cells, which results in a more efficient, less expensive, and more reliable PV system. Keywords: Photovoltaic, maximum power, tracker, pump. Preprint Order Number: PE-808EC (05-2002) Discussion Deadline: October 2002
Coal Mill Modeling by Machine Learning Based on On-Site Measurements Zhang, YG.; Wu, Q.H.; Wang, J.; Oluwande, G.; Matts, D.; Zhou, X.X. Author Affiliation: Electric Power Research Institute; University of Liverpool; National Power PLC. Abstract: This paper presents a novel coal mill modeling technique using genetic algorithms (GA) based on routine operation data measured on-site at a National Power (NP) power station, in England, U.K. The work focuses on the modeling of an E-type vertical spindle coal mill. The model performances for two different mills are evaluated, covering a whole range of operating conditions. The simulation results show a satisfactory agreement between the model responses and measured data. The appropriate data can be obtained without recourse to extensive mill tests and the model can be constructed without difficulty in computation. Thus the work is of general applicability. Keywords: Coal mill, control system, genetic algorithms, system modeling. Preprint Order Number: PE-029EC (05-2002) Discussion Deadline: October 2002
Municipal Solid Waste Fueled Power Generation for India Palanichamy, C.; Babu, N.S.; Nadarajan, C. Author Affiliation: Sultan Saiful Rijal Technical College; Drexel University; Magnum Power. Abstract: The energy policy of the government of India aims at ensuring adequate energy suppiles at a minimum cost, achieving IEEE Power Engineering Review, August 2002
self-sufficiency in energy supplies and protecting the environment from the adverse impact of utilizing energy resources in an injudicious manner. To achieve its goals, the Indian govemment invited the support of the private sectors as before for the development and exploitation of environmental friendly new and renewable sources of energy. This paper proposes one such technology of generating electricity from municipal solid waste (MSW), to be implemented in Tamilnadu State. To do so, a complete feasibility survey has been conducted with a probable developer, and the benefits of this project are compared with the existing wind farm project to attract more investors in future. Keywords: Municipal solid waste, wind farm, electricity generation, environmental issues. Preprint Order Number: PE-005EC (05-2002) Discussion Deadline: October 2002
Adaptive Fuzzy Neural-Network Control for Induction Spindle Motor Drive Lin, F.J.; Wai, R.J. Author Affiliation: National Dong Hwa University.
Abstract: An induction spindle motor drive using synchronous pulse width modulation (PWM) and dead-time compensatory techniques with an adaptive fuzzy neural-network controller (AFNNC) is proposed in this study for advanced spindle motor applications. First, the operating principles of a new synchronous PWM technique and the circuit of dead-time compensator are described in detail. Then, since the control characteristics and motor parameters for high speed operated induction spindle motor drive are time-varying, an AFNNC is proposed to control the rotor speed of the induction spindle motor. In the proposed controller, the induction spindle motor drive system is identified by a fuzzy neural-network identifier (FNNI) to provide the sensitivity information of the drive system to an adaptive controller. The back-propagation algorithm is used to train the FNNI online. Moreover, the effectiveness of the proposed induction spindle motor drive system is demonstrated using some simulated and experimental results. Keywords: Adaptive control, fuzzy neural network, synchronous pulse width modulation, dead-time compensator, induction spindle motor. Preprint Order Number: PE-067EC (05-2002) Discussion Deadline: October 2002
Enhancement of Transient Stability of an Industrial Cogeneration System with Superconducting Magnetic Energy Storage Unit Hsu, C.T. Author Affiliation: Southem Taiwan University of Technology. Abstract: This paper has developed the coordination of load shedding scheme and superconducting magnetic energy storage (SMES) unit to enhance the transient stability of a large industry cogeneration facility. The load-shedding scheme and the tie-line tripping strategy by using the frequency relays have been designed to prevent the power system from collapse when an extemal fault of utility power system occurs. An actual extemal fault case and a simulated intemal fault case have been selected to verify the accuracy of the load shedding scheme by executing the transient stability analysis. To improve the frequency and voltage responses, an SMES unit with various control modes has been installed in the cogeneration system. The sensitivity analysis of the SMES unit with different parameters is applied to achieve better system responses. Besides, a SMES unit with active power deviation as feedback signal is also considered to improve the electric power fluctuation of the study plant with rolling mills. It is found that the SMES system will enhance the electric power quality and minimize the economic losses of the cogeneration facility due to unnecessary load shedding. Keywords: Superconducting magnetic energy storage, cogeneration, transient stability. Preprint Order Number: PE-61 IEC (05-2002) Discussion Deadline: October 2002 IEEE Power Engineering Review, August 2002
Large Band Simulation of the Wind Speed for Real-Time Wind Turbine Simulators Nichita, C.; Luca, D.; Dakyo, B.; Ceanga, E. Author Affiliation: GREAH, the University of Le Havre; University Dunarea De Jos. Abstract: We propose two modeling procedures for wind speed simulation. These procedures could be implemented on the structure of a wind turbine simulator during studies concerning stand-alone or hybrid wind systems. The evolution of a horizontal wind speed has been synthesized taking into account two components. The medium- and long-term component is described by a power spectrum associated with a specific site. The turbulence component is assumed to be dependent on the medium- and long-term wind speed evolution. It is considered as a nonstationary process. Two simulation methods for this component using rational and nonrational filters are proposed. In both procedures, the turbulence model is defined by two parameters, which are either obtained experimentally, or adopted a priori according to information from the considered site. Numerical results and implementation aspects are also discussed. Keywords: Windmills, simulators, real time systems, wind speed, turbulence, power spectral density, numerical simulation, nonstationary signals, shaping filters. Preprint Order Number: PE-074EC (05-2002) Discussion Deadline: October 2002
Probabilistic Model of a Two-Site Wind Energy Conversion System Karaki, S.H.; Salim, B.A.; Chedid, R.B. Author Affiliation: American University of Beirut Abstract: A general probabilistic model of a two-site wind-energy conversion system (WECS) is described. The wind speeds at the two sites are not assumed independent, thus preventing the convolution theorem from being directly applicable. Instead, a model based on the conditional probability theorem and mutually exclusive events is presented. The model allows the assessment of the energy resource available to supply a given load represented by its load duration curve, taking into consideration wind-turbine failure modes and the intermittent nature of the wind resource. The model is based on a capacity-probability table constructed using fundamental probability theorems on conditional and mutually exclusive events. The table is then combined with a load model in order to assess its performance and determine the expected energy not supplied (EENS) of the system. A planning study is then reported on a realistic system to illustrate how the most efficient wind turbines can be selected to support an existing thermal system using a procedure based on a minimization of the incremental marginal cost of operation. Keywords: Renewable energy, reliability evaluation, diesel generators, wind turbines. Preprint Order Number: PE- 1 I OEC (05 -2002) Discussion Deadline: October 2002
Insulated Conductors A Novel Extension Method for Transformer Fault Diagnosis Wang, M.H. Author Affiliation: National Chin-Yi Institute of Technology. Abstract: Dissolved gas analysis (DGA) is one of the most useful techniques to detect incipient faults in power transformers. However, the identification of the faulted location by the traditional method is not always an easy task due to the variability of gas data and operational variables. A novel extension method, which is based on the matter-element model and extended relation functions, is presented for fault diag63
