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Inverter
Kinds of Inverter Selected AbstractsWaveform distortion caused by high power adjustable speed drives part II: Probabilistic analysisEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 6 2003D. Castaldo Waveform distortion caused by high power adjustable speed drives is considered in a probabilistic scenario. In a companion paper, two high computational efficiency drive models, one using the Line Commutated Inverter and the other the Pulse Width Modulated Inverter, have been proposed. These models are used inside a simulation procedure for the probabilistic analysis of waveform distortion on both the supply and motor sides of the two kinds of drives considered. The results obtained considering both mechanical and supply voltage variability are presented and commented. [source] Thin-Film Transistors: Transparent Photo-Stable Complementary Inverter with an Organic/Inorganic Nanohybrid Dielectric Layer (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 5 2009Mater. On page 726, Minsuk Oh and co-workers describe the fabrication of a transparent complementary thin-film transistor inverter with a ZnO top gate and bottom gate of pentacene channels. Twelve nanometer-thin organic,inorganic hybrid dielectric layers with high capacitance are adopted to allow the ZnO and pentacene transistors to operate under only 3 V, and the inverter action appears very stable even under a few mW of white light. This discovery could herald the arrival of a new type of transparent logic device. [source] Transparent Photo-Stable Complementary Inverter with an Organic/Inorganic Nanohybrid Dielectric LayerADVANCED FUNCTIONAL MATERIALS, Issue 5 2009Min Suk Oh Abstract Transparent electronics has been one of the key terminologies forecasting the ubiquitous technology era. Several researchers have thus extensively developed transparent oxide-based thin-film transistors (TFTs) on glass and plastic substrates. However, work in transparent electronics has been limited mostly to high-voltage devices operating at more than a few tens of volts, and has mainly focused on transparent display drivers. Low-voltage logic devices, such as transparent complementary inverters, operating in an electrically stable and photo-stable manner, are now very necessary to practically realize transparent electronics. Electrically stable dielectrics with high strength and high capacitance must also be proposed to support this mission, and simultaneously these dielectrics must be compatible with both n- and p-channel TFTs in device fabrication. Here, a nanohybrid dielectric layer that is composed of multiple units of inorganic oxide and organic self-assembled monolayer is proposel to support a transparent complementary TFT inverter operating at 3,V. [source] A simple instant-estimation method for time-average quantities of single-phase power and application to single-phase power grid connection by inverterELECTRICAL ENGINEERING IN JAPAN, Issue 2 2007Shinji Shinnaka Abstract This paper presents and analyzes a new simple instant-estimation method for time-average quantities such as rms values of voltage and current, active and reactive powers, and power factor for single-phase power with the fundamental component of constant or nearly constant frequency by measuring instantaneous values of voltage and current. According to the analyses, the method can instantly estimate time-average values with accuracy of the fundamental frequency, and estimation accuracy of the power factor is about two times better than that of voltage, current, and powers. The instant-estimation method is simple and can be easily applied to single-phase power control systems that are expected to control instantly and continuously power factor on a single-phase grid by inverter. Based on the proposed instant-estimation method, two methods for such power control systems are also proposed and their usefulness is verified through simulations. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(2): 34,43, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20236 [source] A high-efficiency diode-clamped linear amplifierELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 6 2008Hideaki Fujita Abstract This paper proposes a new power converter without any switching operation and which works as a linear amplifier. The main circuit of the proposed converter consists of series-connected MOSFETs, series-multi DC power supplies, and clamping diodes. The circuit configuration is similar to a diode-clamped multi-level inverter, except for using complementary power devices, which are n- and p-channel MOSFETs. One of the series-connected MOSFETs operates in an active state just like a linear amplifier, while the other MOSFETs operate in on or off states like an inverter circuit. As a result, the proposed converter achieves an acceptable efficiency as high as 90% without any ripples or harmonics caused by switching operation. Experimental results demonstrate that the proposed converter has the capability to drive a 2.2-kW three-phase induction motor. © 2008 Wiley Periodicals, Inc. Electron Comm Jpn, 91(6): 47,56, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10120 [source] Generalised algorithm of novel space vector modulation: for N -level three-phase voltage source inverterEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 2 2008Hachemi Chekireb Abstract This paper concerns the development of a generalised algorithm of a novel space vector modulation (SVM) for N -level three-phase voltage source inverter. It is considering that the (N,1) DC input voltages of inverter are constant. The proposed method ensures initially the determination of the N3 inverter switching states, the extraction of the redundancies to obtain 3N(N -1),+,1 independent switching states and their organisation by sector in six distinct matrices Wk with k,=,(1,,,,,6). After that, these matrices Wk with k,=,(2,,,,,6) are ordered as the matrix W1 related to the first sector. So, the research of the three closest vectors to the reference vector is carried out only in first sector and for this purpose, the equivalent reference vector is introduced which is resulting from the rotation by ,(k,1),/3 of the reference vector. The on-line choice of the three vectors (three switching states of the inverter) is based on the distances between the equivalent reference vector and some vectors located in its vicinity in the (,,,) plane of the first sector. Moreover, a simple method for the calculation of the duty cycles for these three switching states is proposed which exploits directly the three shortest distances associated to these three selected vectors. The sequence of these three switching states over a sampling period is investigated in view to reduce the harmonic contents of the voltage output. The application is carried out on an N -level three-phase voltage source inverter, where N is an arbitrary odd integer. Finally, the phase voltage and its harmonic spectrum provided by a three-phase N- level inverter with N,=,(3,5,7,9,13,15) are presented to confirm the generalisation of this method. Copyright © 2007 John Wiley & Sons, Ltd. [source] Stability analysis and simulation of a single-phase voltage source UPS inverter with two-stage cascade output filterEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 1 2008Jawad Faiz Abstract The primary role of an uninterruptible power supply (UPS) systems is to produce sinusoidal output voltage with minimum total harmonic distortion (THD) and fast dynamic response. This paper investigates the performance of two-stage cascade output filter for single-phase voltage source UPS inverter and it is compared with an LC output filter. The simulation result shows harmonic reduction of output voltage of the inverter due to using multiple-filter. Both THD of the low output voltage and good voltage utilization can be achieved by the proposed filter scheme. The THD of the output voltage in various load condition are all less than 4%. A good agreement between the simulation and experimental results is achieved. Copyright © 2007 John Wiley & Sons, Ltd. [source] Mixed p-z approach for analytical analysis of an induction motor fed from space-vector PWM voltage source inverterEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 6 2002J. Klima This paper proposes an analytical method for calculating both the steady-state and transient performance of an induction motor fed from the three-phase voltage source inverter. As a modulation technique of the inverter we consider space vector modulation. The proposed method makes use of the Laplace and modified Z-transformation of the space vectors (mixed p-z approach) to predict current response of induction motor. From the Laplace transform of the stator voltage vector we can also derive Fourier analysis to predict the voltage harmonic spectrum. Experimental tests have been carried out confirming the validity of the analytical results. [source] Measurements on electrical power systems under bi-tone conditions by using the virtual time-domain approachEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 1 2002L. Peretto The virtual time-domain approach is very convenient for the characterization of multi-tone signals, both quasiperiodic and periodic with very low fundamental frequency. Measurements on a three-phase load controlled by an inverter have been performed by means of a digital method implementing that approach. The results are reported and discussed also in comparison with those provided by a validation procedure. [source] New control system for an ac-excited synchronous machine to achieve a wide field weakening range and a high overload capabilityEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 3 2001J. Haag In the conventional AC-excited synchronous machine operated with mains excitation [1,2], the commutation conditions in the machine-side thyristor converter do not allow the drive to be notably overloaded. In addition operation with field weakening and full four-quadrant operation are not possible due to the principle. If on the other hand the AC-excited synchronous machine is excited by a small insulated gate bipolar transistor inverter (IGBT), then the commutation conditions in the machine-side thyristor converter can be improved with the control system presented here. Therefore a considerable overload capability and a field weakening range of 1:2 and more can be realized with the AC-excited synchronous machine. Areas of application previously excluded are thus opened up to the AC-excited synchronous machine. [source] High power factor ac/dc/ac converter with h-bridge cascade five-level pwm inverterEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 2 2001B.-R. Lin This paper presents an AC/DC/AC converter which consists of a three-phase switch-mode rectifier (SMR) and a three-phase multilevel inverter with separate isolated DC power supplies. Based on a hysteresis current control scheme in the stationary reference frame, the three-phase SMR is controlled to supply sinusoidal currents with high power factor and low current distortion. The separate DC bus voltages are provided by regulated switch-mode DC/DC converters. The series connection of H-bridge cells is adopted to provide multilevel phase voltage. The control scheme of the three-phase multilevel inverter is based on a look-up table with sine-triangular pulse-width-modulation (PWM) method. The voltage unbalance problem between the separate isolated DC bus voltages is improved by using the proposed control scheme. The proposed control algorithm of the AC/DC/AC converter is verified by simulation and experimental results. [source] Thin-Film Transistors: Transparent Photo-Stable Complementary Inverter with an Organic/Inorganic Nanohybrid Dielectric Layer (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 5 2009Mater. On page 726, Minsuk Oh and co-workers describe the fabrication of a transparent complementary thin-film transistor inverter with a ZnO top gate and bottom gate of pentacene channels. Twelve nanometer-thin organic,inorganic hybrid dielectric layers with high capacitance are adopted to allow the ZnO and pentacene transistors to operate under only 3 V, and the inverter action appears very stable even under a few mW of white light. This discovery could herald the arrival of a new type of transparent logic device. [source] Energy-Saving Technologies for Inverter Air ConditionersIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 2 2008Kazunobu Ohyama Senior Member Abstract Almost all residential air conditioners in Japan are inverter air conditioners in which a permanent magnet synchronous motor (PMSM) is driven by a PWM inverter. The inverter technology can reduce the energy consumption to less than half that of air conditioners driven by a constant-speed induction motor (IM). This paper reviews the trends and the latest energy-efficient technologies for the motor and the power converter that achieve considerable energy saving. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Towards Entire-Carbon-Nanotube Circuits: The Fabrication of Single-Walled-Carbon-Nanotube Field-Effect Transistors with Local Multiwalled-Carbon-Nanotube InterconnectsADVANCED MATERIALS, Issue 13 2009Xuelei Liang Single-walled-carbon-nanotube field-effect transistors with multiwalled carbon nanotubes as local interconnects have been fabricated and integrated into a complementary metal oxide-semiconductor inverter. This device prototype sheds light on future integrated circuits made entirely of carbon nanotubes. [source] Trans-admittance control for eliminating the temperature effect of piezoelectric transformer in the CCFL backlight moduleINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 8 2008Yu-Kang Lo Abstract A half-bridge (HB) resonant inverter for driving a cold cathode fluorescent lamp (CCFL) backlight module with a piezoelectric transformer (PT) is analyzed in this paper. The resonant inductance of the HB inverter is expressed as a function of the load current, the load resistance and the PT circuit parameters. Also, the trans-admittance of the PT-CCFL combination network is measured to track the operating frequency for the HB resonant inverter, which may be varied due to the temperature rise of PT. The lamp driving current and power can thus remain almost constant in a wide temperature range. Experiments show that the observed results match the theoretical analyses. Copyright © 2008 John Wiley & Sons, Ltd. [source] Efficient output waveform evaluation of a CMOS inverter based on short-circuit current predictionINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 5 2002A. Chatzigeorgiou Abstract A novel approach for obtaining the output waveform, the propagation delay and the short-circuit power dissipation of a CMOS inverter is introduced. The output voltage is calculated by solving the circuit differential equation only for the conducting transistor while the effect of the short-circuit current is considered as an additional charge, which has to be discharged through the conducting transistor causing a shift to the output waveform. The short-circuit current as well as the corresponding discharging current are accurately predicted as functions of the required time shift of the output waveform. A program has been developed that implements the proposed method and the results prove that a significant speed improvement can be gained with a minor penalty in accuracy. Copyright © 2002 John Wiley & Sons, Ltd. [source] Refrigeration plant exergetic analysis varying the compressor capacityINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 7 2003C. Aprea Abstract The paper presents an exergetic analysis of a vapour compressor refrigeration plant when the refrigeration capacity is controlled by varying the compressor speed. The aim is performance evaluation of both the whole plant and its individual components. The analysis of the exergy flow destroyed in each device of the plant varying the compressor speed has been carried out in order to determine the relative irreversibility of the plant components. The vapour compression plant is subjected to a commercially available cold store. The compressor working with R22, R407C and R507 and designed for a revolution speed corresponding to 50 Hz supply current frequency, has been used varying the frequency in the range 30,50 Hz. In this range, the most suitable working fluids proposed as substitutes of R22, as R407C (R32/R125/R134a 23/25/52% in mass), R507 (R125/R143A 50/50% in mass) and R417A (R125/R134a/R600 46.6/50/3.4% in mass), have been tested. The variable-speed compressor is fitted with a pulse-width modulated source inverter (PWM) predominantly used in medium power applications due to its relatively low cost and high efficiency. The basic difference between variable speed refrigeration and conventional refrigeration systems is in the control of the system capacity at part-load conditions. The conventional refrigeration systems are characterized by compressor on/off cycles arising from by the thermostatic control. On the contrary when the inverter is used the capacity of the refrigeration system is matched to the load regulating the compressor motor speed. When the control of the compressor capacity is obtained by varying its speed there is an energy saving with respect to the thermostatic control. The best results of the exergetic analysis have been obtained using R22 followed by the non-azeotropic mixture designed as R407C that confirms, among the fluid candidates R22 substitution a better performance, shown also at the compressor nominal speed. Copyright © 2003 John Wiley & Sons, Ltd. [source] A fast power loss calculation method for long real time thermal simulation of IGBT modules for a three-phase inverter systemINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 1 2006Z. Zhou Abstract A fast power losses calculation method for long real time thermal simulation of IGBT module for a three-phase inverter system is presented in this paper. The speed-up is obtained by simplifying the representation of the three-phase inverter at the system modelling stage. This allows the inverter system to be simulated predicting the effective voltages and currents whilst using large time-step. An average power losses is calculated during each clock period, using a pre-defined look-up table, which stores the switching and on-state losses generated by either direct measurement or automatically based upon compact models for the semiconductor devices. This simulation methodology brings together accurate models of the electrical systems performance, state of the art-device compact models and a realistic simulation of the thermal performance in a usable period of CPU time and is suitable for a long real time thermal simulation of inverter power devices with arbitrary load. Thermal simulation results show that with the same IGBT characteristics applied, the proposed model can give the almost same thermal performance compared to the full physically based device modelling approach. Copyright © 2006 John Wiley & Sons, Ltd. [source] A hybrid model predictive control approach to the direct torque control problem of induction motorsINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 17 2007Georgios Papafotiou Abstract Direct torque control (DTC) is a state-of-the-art control methodology for electric motor drives which features favourable control performance and implementation properties. In DTC, the core of the control system is the inverter switching table, and any efforts to enhance the system's performance aim at improving its design. This issue is addressed in this paper, where we propose a new design procedure for the DTC problem. The DTC drive, comprising a two- or three-level dc-link inverter driving a three-phase induction motor, is modelled in the hybrid mixed logical dynamical (MLD) framework, and a constrained finite-time optimal control problem is set up and solved over a receding horizon using model predictive control (MPC). Simulation results are provided and compared to the current industrial standard demonstrating the potential for notable performance improvements. Copyright © 2007 John Wiley & Sons, Ltd. [source] A second-order dual-band bandpass filter using a dual-band admittance inverterMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2008Hualiang Zhang Abstract In this article, a second-order dual-band bandpass filter is designed. The filter consists of two dual-band resonators connected by a dual-band admittance inverter. The dual-band resonator unit is made of two shunt stubs that coordinately produce two resonances. A novel dual-band quarter-wavelength line acts as the admittance inverter, providing suitable admittance transformations. To verify the design concept, a filter working at 2 and 5 GHz is devised and fabricated on Rogers' RO3006 printed circuit boards. In addition, the dual-band filter is connected with a bandstop filter to suppress the unwanted spurious response. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1184,1187, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23326 [source] Low-voltage, high-gain, and high-mobility organic complementary inverters based on N,N,-ditridecyl-3,4,9,10-perylenetetracarboxylic diimide and pentacenePHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 2 2008Shuhei Tatemichi Abstract The authors describe an organic complementary inverter with N,N,-ditridecyl-3,4,9,10-perylenetetracarboxylic diimide as an n-type semiconductor and pentacene as a p-type semiconductor. Each transistor of the inverter exhibited high carrier mobility: 1.62 cm2/Vs for an n-type drive transistor and 0.57 cm2/Vs for a p-type switch transistor. The gain of the inverter reached 125. Another inverter using Ta2O5 as a high , gate dielectric performed well with a gain of 500 and an operation voltage of only 5 V. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Integration of enhancement and depletion-mode AlGaN/GaN MIS-HFETs by fluoride-based plasma treatmentPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2007Ruonan Wang Abstract Enhancement-mode AlGaN/GaN metal,insulator,semiconductor HFETs (MIS-HFETs) are demonstrated by combining CF4 plasma treatment technique and a two-step Si3N4 deposition process. The threshold voltage has been shifted from ,4 to 2 V using this technique. A 15 nm Si3N4 layer is inserted under the gate to provide additional isolation between the gate metal and AlGaN surface, which can lead to higher gate turn-on voltage. The two-step Si3N4 deposition process is developed to reduce the gate coupling capacitances in the source and drain access regions, while assuring the plasma-treated gate region being fully covered by the gate electrode. The forward gate turn-on voltage can be as large as 6.8 V. By tuning the plasma treatment parameters, the threshold voltage of the enhancement-mode MIS-HFETs can be raised to as high as 4.3 V. By integrating with depletion-mode MIS-HFETs, a direct-coupled FET logic inverter has been fabricated, with logic low and high noise margins of 2.1 and 2 V. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] DC characteristics and high frequency response of GaN nanowire metal-oxide-semiconductor field-effect transistorPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue S2 2009Jeng-Wei Yu Abstract We report selected site lateral growth of crystalline [110] GaN nanowire (NW) with high channel mobility of 1050 cm2/V-s on SiO2/p-Si. This scheme enables photolithographic fabrication of top-gated GaN NW-MOSFET of 60 nm dia. and 2 ,m gate length. Device parameters with gm of 25 ,S, saturation current of 90 ,A, and cut-off frequency fT at 14 GHz have been extracted. In an active load configuration of GaN NW-MOSFET inverter we reported voltage gain of 2 and a high current on/off ratio of 104. These observations suggest promising functional diversification of the GaN NW-MOSFET on the Si-based CMOS platform for the sub-50 nm technology nodes. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] New control for HVDC system connected to large windfarmELECTRICAL ENGINEERING IN JAPAN, Issue 4 2009Kenichi Tanomura Abstract HVDC consisting of self-commutated inverters is able to be applied for power transmission connecting from a remote large windfarm to a weak AC system. Most self-commutated HVDC is applied for connection between two AC systems that have synchronous power sources, but it is not suitable for a windfarm that consists of induction generators without synchronous power source. This paper presents new control for the self-commutated HVDC system connected to a large windfarm of induction generators. The effect of the proposed control is shown by EMTP simulation. ©2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(4): 31,39, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20539 [source] Voltage fluctuation compensator for ShinkansenELECTRICAL ENGINEERING IN JAPAN, Issue 4 2008Tetsuo Uzuka Abstract In AC electric railways, three-phase voltage is changed into the single-phase circuit of two circuits with the Scott-connected transformer. If unbalancing of the load between single-phase circuits becomes large, voltage fluctuation becomes large on the three-phase side. Railway static power conditioner (RPC) was developed for the purpose of controlling voltage fluctuation on the three-phase side. An RPC is comprised of a pair of self-commutated PWM inverters. These inverters connect the main phase and teaser feeding buses, coupled with a DC side capacitor such as a back-to-back (BTB) converter. In this way, the two self-commutated inverters can act as a static var compensator (SVC) to compensate for the reactive power and as an active power accommodator from one feeding bus to another. 20 MVA/60 kV RPCs started commercial operation in 2002 at each two substations on the newly extended Tohoku Shinkansen for compensating voltage fluctuation on the three-phase side caused by traction loads, absorbing harmonic current. The results of operational testing indicate that an RPC can accommodate single-phase loads such as those of PWM-controlled Shinkansen and thyristor phase-controlled Shinkansen, and handle the exciting rush current of transformers, as well as compensate for harmonics successfully. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(4): 25,34, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20397 [source] Fabrication and evaluation of complementary logic circuits using zinc oxide and pentacene thin film transistorELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 9 2009Hiroyuki Iechi Abstract We fabricated hybrid complementary inverters with n-channel zinc oxide (ZnO) transistors as the n-type inorganic material and p-channel organic transistors using pentacene as the p-type organic material. The complementary inverter exhibited a large voltage gain of 10 to 12 and a cutoff frequency of 0.5 kHz. ZnO thin film transistors show n-type semiconducting properties having field-effect mobility of 2.1×10,3 cm2/Vs. On the other hand, pentacene thin film transistors show p-type semiconducting properties having field-effect mobility of 3.2×10,2 cm2/Vs. We describe basic charge transfer characteristics of ZnO thin films. The results obtained here demonstrate that it is important for the transistor using ZnO to be injected charge from electrode to semiconducting material effectively. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(9): 36,42, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10085 [source] Reduced pole placement method for cascaded frequency control via dispersed pulse invertersEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 4 2005J. Sachau Abstract For modular power systems, structures with parallel power inverters are favourable in view of both easy expandability and supply security. The inverters' embedded controllers are implementing voltage and frequency droops and the superimposed frequency control is coupled via fieldbus. This is a case where a superimposed control is acting via one or more locally dispersed subimposed control-loops. As the states of the subimposed loops are inaccessible, their feedback is no longer viable. The method of reduced pole placement allows reformulation of the design task as complete state feedback without employing a feedback of the single virtual state that just globally describes the one or more subimposed systems. Results are presented for a robust grid frequency controller acting via dispersed pulse inverters. Copyright © 2005 John Wiley & Sons, Ltd. [source] Organic Electronics: High Tg Cyclic Olefin Copolymer Gate Dielectrics for N,N,-Ditridecyl Perylene Diimide Based Field-Effect Transistors: Improving Performance and Stability with Thermal Treatment (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 16 2010Mater. Abstract A novel application of ethylene-norbornene cyclic olefin copolymers (COC) as gate dielectric layers in organic field-effect transistors (OFETs) that require thermal annealing as a strategy for improving the OFET performance and stability is reported. The thermally-treated N,N, -ditridecyl perylene diimide (PTCDI-C13)-based n-type FETs using a COC/SiO2 gate dielectric show remarkably enhanced atmospheric performance and stability. The COC gate dielectric layer displays a hydrophobic surface (water contact angle = 95° ± 1°) and high thermal stability (glass transition temperature = 181 °C) without producing crosslinking. After thermal annealing, the crystallinity improves and the grain size of PTCDI-C13 domains grown on the COC/SiO2 gate dielectric increases significantly. The resulting n-type FETs exhibit high atmospheric field-effect mobilities, up to 0.90 cm2 V,1 s,1 in the 20 V saturation regime and long-term stability with respect to H2O/O2 degradation, hysteresis, or sweep-stress over 110 days. By integrating the n-type FETs with p-type pentacene-based FETs in a single device, high performance organic complementary inverters that exhibit high gain (exceeding 45 in ambient air) are realized. [source] High Tg Cyclic Olefin Copolymer Gate Dielectrics for N,N,-Ditridecyl Perylene Diimide Based Field-Effect Transistors: Improving Performance and Stability with Thermal TreatmentADVANCED FUNCTIONAL MATERIALS, Issue 16 2010Jaeyoung Jang Abstract A novel application of ethylene-norbornene cyclic olefin copolymers (COC) as gate dielectric layers in organic field-effect transistors (OFETs) that require thermal annealing as a strategy for improving the OFET performance and stability is reported. The thermally-treated N,N, -ditridecyl perylene diimide (PTCDI-C13)-based n-type FETs using a COC/SiO2 gate dielectric show remarkably enhanced atmospheric performance and stability. The COC gate dielectric layer displays a hydrophobic surface (water contact angle = 95° ± 1°) and high thermal stability (glass transition temperature = 181 °C) without producing crosslinking. After thermal annealing, the crystallinity improves and the grain size of PTCDI-C13 domains grown on the COC/SiO2 gate dielectric increases significantly. The resulting n-type FETs exhibit high atmospheric field-effect mobilities, up to 0.90 cm2 V,1 s,1 in the 20 V saturation regime and long-term stability with respect to H2O/O2 degradation, hysteresis, or sweep-stress over 110 days. By integrating the n-type FETs with p-type pentacene-based FETs in a single device, high performance organic complementary inverters that exhibit high gain (exceeding 45 in ambient air) are realized. [source] Printed Sub-2 V Gel-Electrolyte-Gated Polymer Transistors and CircuitsADVANCED FUNCTIONAL MATERIALS, Issue 4 2010Yu Xia Abstract The fabrication and characterization of printed ion-gel-gated poly(3-hexylthiophene) (P3HT) transistors and integrated circuits is reported, with emphasis on demonstrating both function and performance at supply voltages below 2,V. The key to achieving fast sub-2,V operation is an unusual gel electrolyte based on an ionic liquid and a gelating block copolymer. This gel electrolyte serves as the gate dielectric and has both a short polarization response time (<1,ms) and a large specific capacitance (>10,µF cm,2), which leads simultaneously to high output conductance (>2,mS mm,1), low threshold voltage (<1,V) and high inverter switching frequencies (1,10,kHz). Aerosol-jet-printed inverters, ring oscillators, NAND gates, and flip-flop circuits are demonstrated. The five-stage ring oscillator operates at frequencies up to 150,Hz, corresponding to a propagation delay of 0.7 ms per stage. These printed gel electrolyte gated circuits compare favorably with other reported printed circuits that often require much larger operating voltages. Materials factors influencing the performance of the devices are discussed. [source] | |||||||||||||||||||||||||||||||