On a wing and a prayer

The article talks about recent Defense Research Projects Agency (DARPA) presolicitation notice in the area of hybrid insect micro-electromechanical systems (MEMs). DARPA's goal is to fund promising interdisciplinary research that will permit the creation of "insect-cyborgs"     

旋转器与反照器的电路综合

为达到多端口回转器的归一化设计,使其能采用集成电路生产和灵活使用的目标,将阻抗实参数对称矩阵Z分解成Z=R0.Gb.R0T的形式,并且给出了求R0、Gb的方法和用(p+q)端口回转器综合对称实参数阻抗矩阵的电路,将二端口旋转器传输参数矩阵方程转化成阻抗矩阵参数矩阵方程,采用对称实参数阻抗矩阵的分解和(3+2)端口回转器综合二端口旋转器的方法,形成(p+q)端口回转器综合旋转器和反照器电路。且只需调整(p+q)端口回转器外接参数即能适应旋转器和反照器的参数变化,故(p+q)端口回转器能用归一化电路器件实现。因此,旋转器与反照器可用归一化单元电路实现。     

Fundamental characteristics of a MEMS‐diaphragm actuator using a thermal expansion drive composed of a conductive polymer

Performance of a MEMS actuator using a thermal expansion drive of a conductive polymer (CP) is investigated by applying electricity to it. The actuator consists of a thin polymer diaphragm (5 mm diameter) and a thin CP (ion‐doped polythiophene) layer coated on the diaphragm surface. Polyimide (10 μm thickness) and PET (110 μm thickness) sheets were chosen as the diaphragm materials. The diaphragm is deflected by the thermal expansion of the CP by applying electricity to it. Merits of using the CP instead of metal are realizing flexible actuators and the applicability to a low‐heat‐resistant material diaphragm. The relationship between thickness of the CP layer (10–50 μm thickness) and electrical resistance (30–600 Ω) and the relationship between the input voltage (1–8 V) and the generated diaphragm displacement (several tens of micrometers) were investigated experimentally. These relationships were compared with those in the case of using the thermal expansion of a vapor‐deposited aluminum layer (0.1 μm thickness). The results of the investigation indicate that the diaphragm based on CP can produce the required displacement. In the case the CP‐layer‐based thermal expansion, however, larger input voltage than in the case of the aluminum‐layer‐based thermal expansion is needed to obtain the same displacement amplitudes. Therefore, the main problem concerning use of the CP‐based diaphragm is considered to be enhancing the electrical conductance of the CP layer. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Method for a Parallel Solution of a Combined Economic Emission Dispatch Problem

The power system simulation software tools are traditionally designed for serial codes and optimized using single-processor computers. They are inadequate in terms of computational efficiency and execution time for the ever-increasing complexity of the power grid. Due to the above-mentioned sequential computing demerits, this paper used MATLAB data parallelism message passing interface software to execute the Lagrange's and Particle Swarm Optimization (PSO) algorithms in parallel with multiple processor units with different and large data sets for the solution of the Combined Economic Emission Dispatch (CEED) problem. The two important advantages of using parallel computing approach to solve the power system economic dispatch problem are 1) to increase the efficiency (solution quality) and 2) to reduce the execution time (speed-up) of the parallelization process for the CEED problem solution. The comparison between the Lagrange's and PSO data-parallel solution quality and execution time is presented for the CEED problem for Institute of Electrical and Electronic Engineers (IEEE) 30 bus and IEEE 118 bus systems. The paper contributes to the on-line real-time market analyses of the deregulated power system, which need improved solution quality and a fast computation process to solve the power system energy management (CEED) problems for proper discussion and decision making at the control center level.     

Extension of a driving-point and a transfer function to a positive real two-port matrix

A solution is presented to the problem, which arises in two-port modelling, of determining a second driving-point function from a given driving-point function and a transfer function. the given functions must have a common denominator and satisfy the necessary positive real (PR) matrix conditions: the driving-point function must be PR and on the imaginary axis the real part of the transfer function must be zero whenever the real part of the driving-point function is zero. By using a partial fraction expansion and determining a required first-order polynomial, a unique second (minimum) driving-point function is obtained. Examples to illustrate the method are worked out.     

Converting a three-phase AC line to a three-wire DC line by a modified converter

Converting existing AC lines to DC for increasing power transmission has been an interesting topic for scientists, such applications could be managed by conventional converters. Converting AC lines to DC upgrades the power capacity of existing lines up to square root of two. In this paper, a modified converter that would use all three existing AC lines at the same time for DC transmission will be introduced. This converter will then be used to model a high-voltage direct current transmission (HVDC) system which enables to convert high-voltage alternating current (HVAC) transmission lines to HVDC lines. The mathematical model of the converter is developed and the system is tested by modeling with PSCAD/EMTDC software for operation and dynamic stability. A practical model is also developed in laboratory conditions and tested for operation.     

Fault-Tolerant Optimal Neurocontrol for a Static Synchronous Series Compensator Connected to a Power Network

This paper proposes a novel fault-tolerant optimal neurocontrol scheme (FTONC) for a static synchronous series compensator (SSSC) connected to a multimachine benchmark power system. The dual heuristic programming technique and radial basis function neural networks are used to design a nonlinear optimal neurocontroller (NONC) for the external control of the SSSC. Compared to the conventional external linear controller, the NONC improves the damping performance of the SSSC. The internal control of the SSSC is achieved by a conventional linear controller. A sensor evaluation and (missing sensor) restoration scheme (SERS) is designed by using the autoassociative neural networks and particle swarm optimization. This SERS provides a set of fault-tolerant measurements to the SSSC controllers, and therefore, guarantees a fault-tolerant control for the SSSC. The proposed FTONC is verified by simulation studies in the PSCAD/EMTDC environment.      

Radiation from a dipole embedded in a dielectric slab

A unified analytical treatment of the radiation from an electric dipole of arbitrary orientation embedded at an arbitrary location within a symmetrically clad dielectric slab is presented. Both the emission into three-dimensional (3-D) radiation modes, corresponding to emission within the critical angle escape cone within the dielectric slab, and into the two-dimensional (2-D) waveguide modes are evaluated from a single calculation. The model is valid for arbitrary dielectric contrast between the slab and the cladding. The mathematical approach uses well-known complex analysis techniques: the 3-D radiation is described by a steepest descents integration around branch cuts while the 2-D waveguide modes correspond to simple poles. The division of the radiated power between the 3-D and 2-D modes is evaluated across the entire range from small dielectric contrast appropriate to diode lasers (≲1,1) to the very large dielectric contrast of free-standing semiconductor slabs (~12-19). Both enhancement and suppression, depending on position, slab width, dielectric contrast, and wavelength, of the total radiated power in comparison with that in an unbounded dielectric-medium are found for slab widths on the order of a wavelength with a maximum enhancement of ~30% for these one-dimensional Fabry-Perot structures. For thicker slabs the total radiation is almost constant and equal to that in the unbounded medium for low dielectric contrast while still exhibiting some modulation as increasing thickness allows additional waveguide modes     

Nonstationary processes in a controlled electric drive with a high-voltage frequency converter intended for a mainline pump of a heat-supply station

Results of the studies of nonstationary electromagnetic and electromechanical processes that develop during the start-up (restart) of a frequency-controlled electric drive of a mainline pump as result of perturbation in the electric supply system are presented.     

Coal-fired small-capacity cogeneration station with a two-zone gas generator with a fluidized bed

The operation of coal gas generator with a fluidized bed is considered, the air gasification products of which are used in the gas-piston internal-combustion engines (ICE) with the electric generator and in the network heaters (heat utilizers) for the heat supply.     

Usefulness of a frequency‐hybrid vector control for a sensorless induction motor drive

This paper examines and demonstrates the usefulness of a frequency‐hybrid vector control scheme for sensorless induction motor drive through actual‐machine‐based performance evaluation tests. The new approach utilizes a new indirect orientation scheme and a stable‐filter‐embedded direct orientation scheme, and exploits their advantages. It is confirmed through extensive tests with small and large standard motors such as 0.3, 3.7, 30 kW and special low‐voltage motors dedicated to electric vehicles that the sensorless vector control scheme has the following potential usefulness: (1) it can make machines that produce more than 200% rated torque at standstill, (2) in both motoring and regenerating modes, the rated torque can be produced even in the very slow speed range, including zero speed and zero frequency, (3) for constant speed, good linearity of torque response is attained, (4) it has the ability to track variable speed acceleration commands up to ±5000 rad/s² in the mechanical frequency sense, (5) it can accept a zero‐speed command and settles the machines to a stable standstill with no vibration, (6) it accepts instant injection of rated load even for zero‐speed control, and (7) it accommodates a load with huge inertia. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(4): 44–58, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10073     

Evaluation of a duplex power transmission bundle as a communication link

The two subconductors which form one phase of a duplex-bundled power transmission line can serve as a wideband (several megaherzt, say) two-wire communications circuit (called an “intrabundle communications” circuit) if the spacers and tower suspension assemblies are suitably insulated. Appropriate modifications to standard spacers and suspension assemblies used in New Zealand are described. The encouraging performance of a trial 1.4 km length of transmission line is reported. Attenuations of 0.17 and 0.29 dB/km were measured at spot frequencies in the 2.5 – 5.0 MHz band.     

Chaos in a series circuit with a nonlinear capacitor and a nonlinear inductor

This paper proposes a nonlinear circuit that generates chaotic oscillations. The proposed nonlinear circuit includes a nonlinear capacitor and a nonlinear inductor by using Generalized Impedance Converters. Both computational experiments and experiments on real circuits show that the region for chaotic oscillation is very wide, demonstrating that the proposed circuit is effective as a chaos generator. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(2): 35–42, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10361     

Monitoring Around a Vehicle by a Spherical Image Sensor

This paper describes a prototype of a full-view spherical image sensor, gives a method for sensor calibration, and discusses display modalities of the captured full-view image for monitoring around a vehicle. To monitor the whole surrounding situation of a dynamic environment by a single camera, a spherical field of view (FOV) is divided into two hemispherical views. Each hemispherical FOV is imaged by a fisheye lens. Both of the hemispherical views are fused by a mirror to acquire them on a single image plane. To calibrate the full-view spherical image sensor, a three-dimensional (3-D) calibration pattern is used to compute the internal parameters of each fisheye lens and their relative orientation based upon a spherical camera model. Finally, several display modalities are discussed to show drivers the relevant spherical image information on planar displays for monitoring around a vehicle     

Small signal stability enhancement of a large scale power system using a bio-inspired whale optimization algorithm

A whale optimization algorithm (WOA)-based power system stabilizer (PSS) design methodology on modified single machine infinite bus (MSMIB) and multi-machine systems to enhance the small-signal stability (SSS) of the power system is presented. The PSS design methodology is implemented using an eigenvalue (EV)-based objective function. The performance of the WOA is tested with several CEC14 and CEC17 test functions to investigate its potential in optimizing the complex mathematical equations. The New England 10-generator 39-bus system and the MSMIB system operating at various loading conditions are considered as the test systems to examine the proposed method. Extensive simulation results are obtained which validate the effectiveness of the proposed WOA method when compared with other algorithms.     

Proposal for a benchmark model of a laminated iron core and a large‐scale and highly accurate magnetic analysis

This paper describes a benchmark model proposed for the clarification of the characteristic of various methods for modeling the laminated iron core. In order to obtain a reference solution of the benchmark model, a large‐scale nonlinear magnetostatic field analysis with a mesh fine enough to represent the microscopic structure of the laminated iron core is carried out by using the hybrid finite element–boundary element (FE‐BE) method combined with the fast multipole method (FMM) based on diagonal forms for translation operators. The computational costs and accuracy of two kinds of homogenization methods are discussed, comparing them with the reference solution. As a consequence, it is verified that the homogenization methods can analyze magnetic fields in laminated iron core within acceptable computational costs. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(1): 26–35, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20809     

Characterizing a Thermoelectric Module as Part of a Semiconductor Course Laboratory

Thermoelectric modules (TEM), also known as Peltier modules, form an interesting topic to cover in an introductory semiconductor course. They provide insight on some important semiconductor principles, namely the Seebeck effect (the reverse of the Peltier effect) and thermal conductance. This paper presents a new methodology to characterize a TEM using a custom-designed test apparatus along with a simplified method for determining the TEM's three key parameters: its Seebeck coefficient, its electrical resistance, and its thermal conductance. Results obtained using this methodology were validated by comparing the anticipated theoretical behavior of the TEM (using the experimentally determined parameters) to the actual results obtained in a vacuum environment. The suggested methodology has been evaluated by students and the results of this demonstrate its usefulness in an educational environment.     

Game-theoretic analysis of a buy-back system and a cogenerator-customer wheeling system

Electricity markets are experiencing widespread changes that are significantly altering the industry. The purpose of this paper is to analyze the economic consequence of various rules of purchased power pricing and wheeling fees of an electric utility by game theory. A regulator, an electric utility, and a cogenerator are included in this model as players of the game. Consider an extensive game model of an electricity market where a cogenerator sells excess electricity to anelectric utility or an end user. The regulator behaves so as to maximize social welfare. The electric utility and the cogenerator intend to maximize their own profit. The wheeling fee between the electric utility and the cogenerator is adjusted to maximize the sum of incremental profits. We have found that a buy-back system (the utility purchases cogenerated power) and a cogenerator-customer wheeling system are equally efficient and are more desirable than a monopoly system. The buy-back rate should be equal to (in the LP bargaining solution) or less than (in the Nash bargaining solution) the marginal cost of the electric utility. We also conducted an analysis of two-period electricity market.     

电压源型SMES 功率调节特性研究

在论述电压源型SMES(VSMES) 调节输出功率的机理的基础上,利用MATLAB 建立了VSMES 的时域仿真模型,利用所建立的模型,分别对VSMES 的有功功率、无功功率及有功和无功同时独立四象限调节特性进行了仿真研究,所得的结论为VSMES 的建模、运行、设计和系统参数的选择提供了依据。     

ESD characteristics of a three-body system including a ground plane

Capacitance coefficients are measured for a system of three conductors positioned above a horizontal ground plane. The system is used to model the approach of a charged floating conductor (the human body) to a two-conductor system (the electronic system under test) in which either or both conductors are floating or one is grounded. Body potentials and energies are calculated for various source/sink geometries and ground plane separations; both main and second discharge conditions are analyzed. The results, which are based on the measurement of system capacitance coefficients, provide a better understanding of the basic ESD characteristics of the three-body problem. The information can be applied in the design of electronic systems and is of use in the simulation and analysis of the ESD event