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This paper discusses the effect of temperature on polarization and depolarization current measurements on paper oil insulation system. The influence of copper sulphide formed due to corrosive sulphur in mineral oil, on the changes in polarization and depolarization current at different temperatures are considered. A significant increase in the magnitude of polarization and depolarization currents due to deposits of copper sulphide on paper layers is observed. The conductivity of paper insulation increases significantly with increase in temperature. The increase in current is attributed to thermally active conducting particles of copper sulphide. The Debye model parameters of equivalent circuit under copper corrosion have been computed and a model for failure due to copper sulphide is explained using the data on polarization and depolarization currents. [ABSTRACT FROM PUBLISHER]

This paper proposes a method for estimation of tanδ of cellulosic parts in oil-paper insulation from frequency domain spectroscopy based on equivalent circuit model of oil-paper insulation in real-life transformers. Existing literature shows that overall condition of oil-paper insulation in transformer can be assessed by conventional frequency domain spectroscopy. Also, the condition of oil can be separately and easily predicted through analyzing its dielectric properties by taking out the oil samples from transformer. However, it is quite difficult to assess the dielectric properties of cellulosic parts in oil-paper insulation as it cannot be directly accessed from outside for an operating transformer. Considering the aforesaid fact, this paper presents a segregated equivalent circuit model of composite oil-paper insulation that can separately estimate the tanδ profiles for oil as well as cellulosic parts. The tanδ profiles of cellulosic parts obtained from the equivalent circuit model have been validated experimentally. Results show that the tan? profile obtained from experimental result holds good agreement with that of the proposed model. [ABSTRACT FROM PUBLISHER]

In comparison with the AC and DC working voltages, the effect of switching impulse voltage on insulation is very different because of its fast-rising rate and large amplitude. This paper mainly focuses on the characteristics of PD in oil-impregnated paper insulation under switching impulse voltage. First, a robust experimental platform was set up including the impulse power source, test samples with uniform gas and oil gap, and the signal acquisition and processing system. PD characteristics in the air and oil gap are analyzed and compared involving the time-domain waveforms, the variation tendency of the average amplitude and numbers of PD pulses, the occurrence time and the instantaneous value of impulse corresponding to the first PD. Based on the dielectric barrier discharge (filament) theory, a parallel microcircuit model was established to explain the similarities and dissimilarities, and to evaluate the gap discharge intensity. The occurrence and development of PD under switching impulse voltage of typical oil-impregnated paper defect were studied systematically with simulation, experiments, and modeling. [ABSTRACT FROM AUTHOR]

The paper presents new diagnostic method applied to assess aging degree for paper-oil insulation used in professional electrical power device, primarily including medium and high power transformers. The described method is based on modified diagnostics using the recovery voltage effect occurring in dielectrics (RVM ? Recovery Voltage Methods). Modification of the RVM method applied so far, which is now used only to assess moistening degree for paper-oil insulation in power transformers, consists in a new parametric analysis of recovery voltage time characteristics. Simulation and experimental tests carried out in laboratory conditions for adequately prepared insulation samples have proven that the time-constant of recovery voltage decay (?R_MIN) is the most susceptible parameter as regards quantitative change in the function of aging of the examined insulation. This conclusion is also confirmed by statistical studies, in which a multi-parameter variance analysis method has been applied. An original equivalent circuit diagram of the insulation has been used to simulate aging degree of paper-oil insulation samples in numerical tests. The diagram is based on the Cole-Cole type dielectric response model. [ABSTRACT FROM AUTHOR]

Samples of a dried composite oil-paper system were thermally aged in the laboratory under N2 in a sealed container and analysed using their dielectric response. The contributing loss processes were separated using an equivalent circuit model containing constant high frequency capacitances, dc-conductances, a dispersive capacitance, and a low frequency quasi-dc (q-dc) dispersion process as circuit elements. This low frequency dispersion in oil-paper samples is a bulk property of the system that is often mistaken for a dc conduction process when only the imaginary capacitance or ac-conductance is measured. The Dissado-Hill response function is proposed for the frequency dependence of the dispersive capacitance in the mid-frequency range rather than the Debye function because its cluster concepts correlate with the sample morphology of a matrix of oil-filled cavities. The quasi-dc dispersion is assigned to the transport of mobile charges between charge-clusters associated with locally connected oil filled cavities, which is a process that can be represented on a global scale by the form of hierarchical circuit system that leads to constant phase angle responses, and is here modelled by the Dissado-Hill q-dc function. It was found that the two dispersions moved together to higher frequency with thermal ageing of the composite material. The characteristic frequency common to the dispersions had an activation energy that decreased with thermal ageing, whereas their amplitude increased. This behavior is discussed in terms of possible changes to the oil-paper composite caused by the ageing process. [ABSTRACT FROM AUTHOR]

Compared to conventional ac cables, the current rating of HVDC cable circuits is more complicated because the permissible current is not only limited by the operating temperature, but also by the electrical stress within the insulation. Therefore the IEC60287 current rating standard is considered insufficient for some HVDC applications because it fails to include the stress limitation. This paper presents an analytical methodology to calculate an electrical stress-limited rating for HVDC cables, which considers the maximum dielectric stress as the current limiting factor. This paper represents the first part of a project which has comprehensively reviewed cable rating calculations for mass impregnated HVDC cable systems. [ABSTRACT FROM PUBLISHER]

This article presents a bibliography of the papers related to relay literature. The papers listed in this bibliography include references to the subjects of service restoration, testing and methods of calculation well as to the field of relaying. The references also include the title, author, publication information and a summary of the subject matter. Some of the entries in this bibliography are: "Symmetrical Components Estimation through Non-Recursive Newton-type Numerical Algorithm," "Signal Processing Module for Power System applications," "Variable-Window Algorithm for Ultra-High-Speed Distance Protection," "Wavelet-Based ANN Approach for Transmission Line Protection," and "Enhanced Transmission Line Protection Settings."

This paper proposes a systematic method for the identification of the load circuit parameters (say the $\boldsymbol{R}$ , $\boldsymbol{L}$ , and $\boldsymbol{C}$ elements) based only on the information of the instantaneous voltage and current measured at the point of common coupling (pcc). Geometric Algebra (GA) and concepts of differential geometry are used to produce a rigorous mathematical framework. The identification is formulated as a multidimensional geometrical problem that is solved conveniently by means of GA. Once the passive elements of the load have been identified, the active and reactive powers can be computed from first electromagnetic principles (Maxwell Equations). The theory is general and is verified with linear and nonlinear circuits. The paper shows single-phase circuits but the theory can be extended to three-phase circuits. The method is easy to program and has shown to be very robust for all tested cases. Because of its generality, the method presented will find applications beyond electric circuits. [ABSTRACT FROM AUTHOR]

An increasing need for fast and reliable models has led to a continuous development of Fourier-based (FB) analytical modeling. This paper presents an overview of the techniques that are currently available in FB modeling for electric machines. By coupling that overview to the most relevant literature related to the subject, an interesting starting point is provided for anyone who wants to use or improve FB models. The following seven aspects of FB models are discussed in detail: 1) the magnetic potential (scalar or vector potential); 2) the coordinate system and the solution of the partial-differential equations for each magnetic potential and for each coordinate system; 3) the way in which time dependence is accounted for; 4) the implementation of the source terms; 5) the possibilities to account for slotted structures; 6) the modeling of eccentricity; and 7) the post-processing computation of physical quantities, such as flux density, electromotive force, torque, losses, and eddy currents in conductive objects. Furthermore, this paper gives the closed form solution of the Laplace, Poisson, and Helmholtz equations in each coordinate system. In addition, this paper tackles other important features of FB models such as computational time reduction and coupling the machine model to an electric circuit. [ABSTRACT FROM AUTHOR]

A call for papers for 2014 IEEE International Reliability Physics Symposium on topics related to circuits and products and devices process and materials reliability.

A transient and static hybrid-triggered active clamp is proposed in this paper. By skillfully incorporating different detection mechanisms, the proposed clamp achieves enhanced static electrical overstress protection capability over the transient one. Furthermore, the proposed clamp achieves improved electrostatic discharge reaction speed in both human body model and charged device model events over the static one. Moreover, the superior transient-noise immunity of the proposed clamp over traditional transient ones is essentially revealed in this paper. The proposed clamp is successfully verified in a 65-nm bulk CMOS process. In addition, the design flexibility of the proposed clamp for other processes is also deeply discussed in this paper. [ABSTRACT FROM PUBLISHER]

Provides instructions and guidelines to prospective authors who wish to submit manuscripts. [ABSTRACT FROM AUTHOR]

Comments on a paper which suggests a ring hybrid adopting a Marchand balun. Use of the main concept that the ring hybrid consists of an in-phase divider and a balun; Comparison between measured and theoretical results of a Marchand balun without an in-phase power divider.

With the increasing ubiquity of computing, more engineering programs now require their students to take one or more computing courses. At institutions where significant numbers of engineering students take computer courses, computing instructors and educators often assume roles that have them teaching their computing courses for non-majors as service courses, dealing with students with diverse backgrounds and varied motivations. Although teaching computing courses to non-majors is not new, the increasing importance of computing in future undergraduate engineering curricula poses new challenges. In this Special Issue, four of the papers offer insight into, and give evidence of, teaching computing to engineering students; the fifth paper investigates computational modeling abilities in conceptual understanding of electric circuits. [ABSTRACT FROM AUTHOR]

This paper proposed a method of synthesizing absorptive common-mode filters (A-CMFs) analytically with high absorption efficiency and two designable absorption bands. The proposed method is carried out by a novel circuit architecture and its analysis procedure. In differential mode, the integrity of the differential signals is maintained, and in common mode (CM), two absorption frequency bands can be obtained theoretically. These bands are designable with the analytical equations derived in this paper, so a dual-band or broadband A-CMF design can be easily synthesized by our proposed method. The authors also show that this method can make any one of R-CMFs “upgrade” to an A-CMF by simply adding an additional circuit, and this might be a revolutionary progress for the currently used CM-suppression techniques. To make the proposed concept more understandable, an example is used to demonstrate how the synthesizing methodology works, where a broadband A-CMF with its absorption bands located at 2.4 and 3.6 GHz is designed and implemented. Furthermore, a test sample of this A-CMF is fabricated on a four-layer printed circuit board. It is measured on a probing station, and the measured results are very similar to the simulated results. Finally, a comparison table of all the related works is given, showing that this proposed method really makes a significant improvement for A-CMF techniques. It is worth noting that this circuit design can provide a broadest 95%-absorption band to our best knowledge. [ABSTRACT FROM AUTHOR]

In this paper, the analysis of the accuracy of the electromagnetic time reversal method for unmatched media is carried out when the terminal impedances of the transmission line and/or of the defects along it are frequency dependent. Some numerical examples involving a medium-voltage power line and a high-speed interconnect are considered and the results discussed. [ABSTRACT FROM AUTHOR]

Stacks of 2-D materials, known as van der Waals (vdW) heterostructures, have gained vast attention due to their interesting electrical and optoelectronic properties. This paper presents an intuitive circuit model for the out-of-plane electrostatics of a vdW heterostructure composed of an arbitrary number of layers of 2-D semiconductors, graphene, or metal. We explain the mapping between the out-of-plane energy band diagram and the elements of the equivalent circuit. Although the direct solution of the circuit model for an n-layer structure is not possible due to the variable, nonlinear quantum capacitance of each layer, this paper uses the intuition gained from the energy band picture to provide an efficient solution in terms of a single variable. Our method employs Fermi–Dirac statistics while properly modeling the finite density of states (DOS) of 2-D semiconductors and graphene. The approach circumvents difficulties that arise in commercial TCAD tools, such as the proper handling of the 2-D DOS and the simulation boundary conditions when the structure terminates with a nonmetallic material. Based on this methodology, we have developed 2dmatstacks, an open-source tool freely available on nanohub.org. Overall, this paper equips researchers to analyze, understand, and predict experimental results in complicated vdW stacks. [ABSTRACT FROM AUTHOR]

First harmonic analysis (FHA) is arguably the most widely used analytical technique for wireless power transfer (WPT) circuits due to its simplicity. Although FHA can provide closed-form solutions, the existence of rectifier diode forward voltage drop and higher order harmonics, especially the second and third harmonics at variable duty cycle operation, can significantly deteriorate its accuracy. This paper presents an accurate and efficient method called enhanced multiple harmonic analysis (eMHA) for the optimal design and optimal control of WPT systems. The eMHA method considers the nature of nonlinear rectification networks under nonsinusoidal current and reexamines the concept of the equivalent load. As a result, the rectified WPT system is transformed into a series of linear systems with complex load impedances. The steady-state electric quantities can be then explicitly calculated. This enables eMHA to seamlessly work with numerical optimization algorithms to facilitate the automated design and optimization of WPT systems. An example of optimal design and optimal control of a 10 W WPT system is demonstrated. The results obtained by eMHA and FHA are also compared. A prototype of the designed circuit was constructed. The accuracy and effectiveness of eMHA are verified by experimental measurements. This paper is accompanied by a MATLAB-based analytical tool with a graphical user interface demonstrating the effects of circuit variables on electrical quantities and waveforms. [ABSTRACT FROM AUTHOR]

Railguns are current-driven guns that allow reaching large muzzle velocities and energies. In the military context, the long-range artillery scenario makes use of these two capabilities to enable the launch of hypervelocity projectiles to target distances above 100 km. As of today, the most advanced railgun project is conducted by the Office of Naval Research, Arlington, VA, USA, and features railguns with a muzzle energy of 32 MJ. Such large artillery railgun systems with efficiencies above 30% are fed by a pulsed power system with a nominal energy content of about 100 MJ. In contrast to this, experiments with French-German Research Institute’s (ISL) most powerful railgun, PEGASUS, have reached muzzle energies of 2 MJ, only. The nearer future ISL has to answer two questions: 1) is the railgun technology adequate for a long-range artillery scenario? 2) can the railgun launch a hypervelocity projectile which is being developed by other groups in ISL? To do so and to support the development of the hypervelocity projectile, a larger railgun installation with a significant increase of the energy and free flight capability is required. In this paper, three different railgun systems were investigated using an electric circuit simulation code. The systems are referred to by the energy being stored in the capacitors as 25, 50, and 100 MJ. The aim of this paper is to investigate what masses can be accelerated to the relevant velocity range for the long-range artillery scenario by these different primary energies. The results of this paper can be used to aid the decision about the required size, with respect to the military scenario, of a potential future railgun system. [ABSTRACT FROM AUTHOR]

This paper describes a multifunctional microwave device that can be reconfigured to behave either as a filter or an antenna. The device is based around a single-resonant element, referred to as a building block element that is connected to four ports. The resonant element is a microstrip square patch working in the 2.45 GHz unlicensed Industrial Scientific and Medical band used for IEEE 802.11 WiFi. The proposed building block is simple in its design and construction. This paper also presents devices composed of three building blocks, which can realize more complex filtering and antenna mode performance. In addition, p-i-n diodes have also been incorporated into the devices in order to facilitate electronic control. Measured results, pertaining to fabricated prototypes, show that filter and antenna operation can be achieved in the same device at a frequency of around 2.45 GHz with acceptable insertion loss and efficiency. In the future, it is anticipated that this could lead to a new paradigm, namely, a device that is analogous to a field programmable gate array operating in the microwave frequency regime. [ABSTRACT FROM AUTHOR]

This paper describes the International Electrotechnical Commission (IEC) type A (ac only) ground-fault detection circuit and its limitations in accurately detecting electrical ground-fault currents in today's modern electrical installations. Discussed are the effects of waveform modifying power sources and the effect of the dc component on the efficacy of type A safety devices. Limitations of the UL1053 standard for ground-fault sensing and relaying equipment are discussed. The paper will lead to recommending and applying IEC type B (ac/dc) detection technology for solving these shortcomings. [ABSTRACT FROM PUBLISHER]

Recently, voltage-source converter (VSC)-based high-voltage dc (HVDC) transmission systems have gained more attention. In this paper, a control method for a modular VSC-based HVDC transmission system with high-frequency isolation referred to as high-frequency isolated modular converter is proposed. In the high-frequency isolated modular converter configuration, several floating dc capacitors in all three phases are connected in series, and voltage balancing control of these floating dc capacitors is required. In this paper, an appropriate control structure with the capacitor voltage balancing controller is proposed. The proposed control scheme consists of three layers to control terminal dc bus voltage and balance dc capacitor voltages of each building block. Detailed PSCAD simulation results are presented to evaluate the performance of high-frequency isolated modular converter. Controller hardware-in-the-loop simulation of the high-frequency isolated modular converter is also performed by real-time digital simulator (RTDS), and RTDS results are presented to verify the control structure. Finally, laboratory-scale experimental results are presented to validate the proposed control method. [ABSTRACT FROM PUBLISHER]

Prestrike phenomenon in circuit breakers (CBs) can cause electromagnetic transients in power systems. Therefore, the investigation of this phenomenon has considerable importance. The scope of this paper is to investigate the effects and importance of arcing contact shape on the prestrike in SF6 gas CBs. In order to simulate the prestrike with high accuracy, a multi-physics model is developed precisely. In this model, equations of motion of the SF6 gas, the electric charge conservation equation, turbulent equations, heat transfer equation in fluids, and the governing equations of an electric circuit in which the CB works are considered simultaneously. The numerical study is performed on a 72.5-kV single pressure puffer type SF6 CB. Three different types of arcing contacts are investigated in this paper. Numerical results show that the arcing contact shapes have an important effect on the prestrike in gas type CBs. [ABSTRACT FROM AUTHOR]

The frequency dependence as well as the current dependence of grounding resistance affects lightning overvoltages in electric power system. This paper proposes an equivalent circuit to simulate the frequency dependence of soil resistivity and permittivity. Constants of the equivalent circuit are determined based on empirical formulas for the frequency dependence of the soil parameters proposed by Alipio and Visacro. The equivalent circuit is represented in time domain. Therefore, the equivalent circuit is applicable to the calculation of the current dependence of the grounding resistance. An influence of the frequency dependence of the soil resistivity and permittivity on the current dependence of the grounding resistance is discussed by the use of the equivalent circuit. This paper proposes a modified CIGRE model to calculate the current dependence of the grounding resistance. The equivalent circuit is very convenient and useful for engineers to carry out lightning surge analysis. [ABSTRACT FROM AUTHOR]

In this paper, we propose a compact topology for high-frequency bandpass filters using coaxial cavities embedded in a bed of nails, including a complete design procedure combining equivalent circuit models and full-wave simulators. The resonance generated around a shortened cylindrical nail of the bed hosting structure is used as the basic element of the proposed filter, which is fed through groove gap waveguides. For design purposes, an equivalent circuit model of the considered resonance is first obtained, and then the coupling levels between resonators are recovered with the distance between adjacent shortened nails. In order to validate the proposed structure and its design procedure, a filter prototype with a bandpass response (centered at 30 GHz and with relative bandwidth of 1.7%) has been designed, manufactured, and measured. Good experimental results, in terms of insertion losses (with a minimum value of 1.6 dB) and return losses (greater than 16.6 dB in the whole passband), have been achieved. [ABSTRACT FROM AUTHOR]

Fully coupled transient analysis of electromagnetic (EM)-circuit systems is highly desirable for a number of applications. Over the last decade or so, there have been several papers that present effective solutions to this problem within the context of full-wave differential or integral equation solvers. The method typically espoused is as follows: discretize the underlying EM system, couple with the circuit subsystem self-consistently, and then solve the coupled system. Within this framework, nonlinearities are easily accounted for in the solution process. This is in direct contrast to frequency domain analysis, wherein one defines ports that couple the EM and circuit subsystems, i.e., the representation of the EM system using an effective impedance/admittance as seen at the circuit terminals. This approach permits: 1) solution only at the circuit level and 2) one can readily incorporate different circuits without having to solve the coupled system repeatedly. Achieving the same functionality in the time domain is a challenge. In this paper, we present a solution to this problem. We will prescribe the means to effectively represent the EM subsystem in terms of a transient admittance, thus facilitating a solution to the coupled system via a circuit-level solve. Several results are presented that serve to validate the proposed approach and demonstrate its effectiveness. [ABSTRACT FROM AUTHOR]

The poor quality of the die stacking process for 3-D integrated circuits can result in the failure of the process in the through-silicon-vias (TSVs) in dense regions. Previous works use the same number of redundant TSVs and architectures that do not consider the TSV density. A repair architecture and an appropriate number of redundant TSVs, which are chosen considering the TSV density, are required for an improved repair rate. This paper proposes a method that demonstrates such an architecture and calculates the required number of TSVs. The method has a high repair rate for clustered faults, and wire-length problems are solved using the shift-based repair method. [ABSTRACT FROM AUTHOR]

Due to many state-holding elements in asynchronous circuits, many faults need two-pattern tests. This paper presents a test methodology (DR-scan) for dual-rail asynchronous circuits. Our design for testability is a full-scan, clock-less technique that supports both one-pattern and two-pattern tests for single stuck-at faults. DR-scan is able to test memory elements in dual-rail logic without breaking local feedback loops. To reduce test time, we choose a minimum set of selected test configurations (TCs). If there are more than one selected TCs, we need to split scan latches into multiple scan chains. To apply two-pattern tests, we partition the circuit using vertex coloring. With our test methodology, we can apply traditional full-scan automatic test pattern generation (ATPG) to generate two-pattern tests with high test coverage. Experimental results show our methodology can achieve test coverage up to nearly 94% for various asynchronous circuits. [ABSTRACT FROM AUTHOR]

This paper describes the fringing electric field modeling and performance of four different shaped poly methyl methacrylate-coated capacitive sensors for soil moisture measurement. Experiments are carried out in the laboratory by placing the sensor inside the soil. The analytical solution for such fringing field system is difficult to obtain, so COMSOL Multiphysics software is used for modeling the capacitive sensor surrounded by the soil. Experimental data are compared with the software simulated value. Statistical root-mean-square error (RMSE) and percentage of normalized RMSE for polynomial fit are studied for the sensitivity and performance analysis. Effect of external temperature on the performance of the sensor is also discussed. The proposed signal conditioning circuit is implemented in printed circuit board to measure the output voltage with respect to capacitance change. Obtained results are transmitted through a global system for mobile communication module for remote observation of soil moisture. The thermogravimetric method is used for voltage to soil moisture calibration, and based on the experimental data, results are analyzed further. A review of some relevant fringing field capacitive sensors and their instrumentation system reported in past 7–8 years are studied for comparison with the proposed sensor system. [ABSTRACT FROM AUTHOR]

A parallel hybrid modular multilevel converter (PHMMC) belongs to the class of modular multilevel converters, which have become potential candidates for high-voltage direct-current (HVDC) transmission systems. Due to the circuit topology of a PHMMC, the dc bus voltage contains low-order harmonics and cannot be fully regulated at a constant dc voltage. The dc bus voltage, if not properly controlled, leads to improper power transfer and increases the magnitude of dc current ripple on the dc transmission line. This paper proposes a zero-sequence voltage injection (ZSVI)-based model predictive control (MPC) strategy to control the dc current/power flow and simultaneously minimize the dc current ripple. The proposed strategy takes advantage of a cost function minimization technique to determine and inject the optimal zero-sequence voltage components into the dc- bus voltage of a PHMMC system. This paper derives a discrete-time dynamic model of the dc transmission-line current and, correspondingly, develops a predictive model. The predictive model is used to inject the appropriate amount of zero-sequence voltage components to the dc bus reference voltage waveform. Compared with the existing triplen harmonics injection method, the proposed ZSVI-MPC strategy improves the performance of a PHMMC system in terms of minimization of the dc current/voltage ripple. Performance of the proposed strategy for a 21-level PHMMC-based HVDC station system is evaluated based on time-domain simulation studies in the PSCAD/EMTDC software environment. The reported results demonstrate superior performance of the PHMMC-HVDC station operating based on the proposed ZSVI-MPC strategy, under various operating conditions, as opposed to the existing triplen harmonics injection method. [ABSTRACT FROM AUTHOR]

This paper focuses on the security condition of line worker during the implementation of helicopter live-line work by platform method on 1000 kV ultrahigh voltage (UHV) transmission lines. First, a model of helicopter live-line work is presented, and the electric field distribution of line worker when performing live-line work on 1000 kV UHV transmission lines is analyzed. Then, the capacitances between helicopter live-line work platform, transmission lines, and ground are obtained by energy method, and an equivalent circuit model is presented to analyze the current characteristic of bonding procedure. At the end of this paper, an experiment of helicopter live-line work is performed, the electric field distributions of line worker and the discharge current are measured and compared with simulation results, which will be used to judge the security condition of line worker and the feasibility of helicopter live-line work by platform method on 1000 kV UHV transmission lines. [ABSTRACT FROM PUBLISHER]

This paper proposes a novel kind of direct-current and alternate-decay-current hybrid integrative magnetization and demagnetization power supplies applied to transformer dc bias treatment based on a nanocomposite magnetic material. First, according to the single-phase transformer structure, one dc bias magnetic compensation mechanism was provided. The dc bias flux in the transformer main core could be eliminated directionally by utilizing the material remanence. Second, for the rapid response characteristic of the magnetic material to an external magnetic field, one positive and negative dc magnetization superimposed decaying ac demagnetization hybrid integrative power supplies based on single-phase rectifier circuit and inverter circuit was designed. In order to accurately control the magnetic field strength by which a good de/-magnetization effect could be achieved, this paper adopts the double-loop control technology of the magnetic field strength and magnetizing current for the nanocomposite magnetic state adjustment. Finally, two 10 kVA transformers and the experiment module of the hybrid integrative power supplies were manufactured and built. Experimental results showed that the integrated power supplies have good de/-magnetization effect and practicability, proving the validity and feasibility of the proposed scheme. [ABSTRACT FROM AUTHOR]