Current Source Power Supply Research Articles

A pulsed bipolar current-mode power supply with high power factor in a single stage for dielectric barrier discharge application

Purpose Dielectric barrier discharge (DBD) is widely used in the treatment of skin disease, surface modification of material and other fields of electronics. The purpose of this paper is to design a high-performance power supply with a compact structure for excimer lamps in electronics application. Design/methodology/approach To design a high-performance power supply with a compact structure remains a challenge for excimer lamps in electronics application, a current-source type power supply in a single stage with power factor correction (PFC) is proposed. It consists of an excitation voltage generation unit and a PFC unit. By planning the modes of the excitation voltage generation unit, a bipolar pulse excitation voltage with a high rising and falling rate is generated. And a high power factor (PF) on the AC side is achieved by the interaction of a non-controlled rectifier and two inductors. Findings The experimental results show that not only a high-frequency and high-voltage bipolar pulse excitation voltage with a high average rising and falling rate (7.51GV/s) is generated, but also a high PF (0.992) and a low total harmonic distortion (5.54%) is obtained. Besides, the soft-switching of all power switches is realized. Compared with the sinusoidal excitation power supply and the current-source power supply, the proposed power supply in this paper can take advantage of the potential of excimer lamps. Originality/value A new high-performance power supply with a compact structure for DBD type excimer lamps is proposed. The proposed power supply can work stably in a wide range of frequencies, and the smooth regulation of the discharge power of the excimer lamp can be achieved by changing the switching frequency. The ideal excitation can be generated, and the soft switching can be realized. These features make this power supply a key player in the outstanding performance of the DBD excimer lamps application.

Analysis and Experimental Validation of an Integrated Current-Source Power Supply With High Power Factor for DBD Applications

An integrated current-source high-frequency pulse excitation power supply with high power factor (PF), low total harmonic distortion (THD) of the input current, and high efficiency for dielectric barrier discharge (DBD) loads is proposed in this article. The proposed power supply consists of a current source unit and a bipolar pulse excitation voltage generation unit. The current source unit is used to generate a current source for the excitation voltage generation unit and achieve a high PF and a low current harmonic distortion in the ac side of the proposed power supply. By planning the modes of the excitation voltage generation unit, not only a bipolar pulse excitation voltage with high rising and falling rates on the DBD loads is generated, but also the soft-switching of all power switches is achieved. The experimental results show that not only a unity PF ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&gt;$</tex-math> </inline-formula> 0.99) and a low THD ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&lt;$</tex-math> </inline-formula> 10%) are achieved, but also a bipolar high-frequency (hundreds of kilohertz) pulse excitation voltage with high average rising and falling rates (7.227 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> 109 V/s) for a DBD excimer lamp is generated. Finally, in comparison with different power supplies, the proposed power supply can not only fully take advantage of the potential of the DBD excimer lamp but also has many advantages of high efficiency (92%), integrated structure, and simple driver.

Thermionic Electron Beam Current and Accelerating Voltage Controller for Gas Ion Sources

Thermionic emission sources are key components of electron impact gas ion sources used in measuring instruments, such as mass spectrometers, ionization gauges, and apparatus for ionization cross-section measurements. The repeatability of the measurements taken with such instruments depends on the stability of the ion current, which is a function, among other things, of the electron beam current and electron accelerating voltage. In this paper, a laboratory thermionic electron beam current and accelerating voltage controller is presented, based on digital algorithm implementation. The average value of the percentage standard deviation of the emission current is 0.021%, and the maximum electron accelerating voltage change versus the emission current is smaller than 0.011% in the full operating range of the emission current. Its application as a trap current or emission current-regulated ion source power supply could be useful in many measuring instruments, such as in microelectromechanical system (MEMS) mass spectrometers as universal gas sensors, where a stable emission current and electron energy are needed.

Design of automatic measurement system for pre-tightening parameters of multi-axis wrist force pressure sensor

Aiming at the shortcomings of low efficiency and poor accuracy of the existing pressure sensor pre-tightening parameter measurement system, an automatic multi-axis wrist force sensor pre-tightening parameter measurement system is designed. The multi-axis wrist force sensor module is used to collect real-time tension signal from the loaded hand wheel. After amplification, the signal is transmitted to the multi-channel gating module through RS485 communication module to realize the tested sensing. After fast switching and constant current source power supply control function, the data collector collects the pull signal obtained by multi-axis wrist force pressure sensor and transmits it to the upper computer of the system designed by LabVIEW through RS485 bus. The upper computer controls and collects the pressure sensor according to the pull signal feedback from the data collector, and the pre-tightening displacement of multi-axis wrist force sensor is determined by parameters such as axial displacement and friction resistance moment. The experimental results show that the designed system can fully measure the pre-tightening parameters of the sensor, and the starting moment measurement error is only 0.102%. The system can meet the requirements of batch measurement and calibration of multi-axis wrist force sensor with accuracy of 1%-0.1%.

Torque/current spectral analysis for healthy and eccentricity faulty synchronous reluctance machine using mathematical modeling method

Summary In this research, considering slot opening and distributed winding effects, torque ripple analysis is studied for four separate synchronous reluctance machines (SynRMs) under health and eccentricity fault conditions using a mathematical method. A finite element method (FEM) validated model is produced by mathematical modeling, and numerical method is used for the machine's behavior studying with voltage source supplying. With this aim, the machine's parameters have been computed under health and eccentricity fault conditions, using modified winding function theory (MWFT). A method of dynamic and static eccentricity fault diagnosis is proposed, which uses machine vibration analysis, and the results suggest that the eccentricity fault does not have any significant effect on the machine's currents. Moreover, unbalance magnetic pull (UMP) is computed under eccentricity fault conditions and mechanical un-stability is shown. Mathematical base model and voltage source machine supply and also presenting a discrete machine modeling method are the main advantages of this paper compared with other similar works that are usually FEM-based studies or have been based on current source power supply. The research is applicable to healthy and faulty machine behavior, and the methodical modeling is obviously applicable to other machines. Copyright © 2015 John Wiley & Sons, Ltd.

The Feasibility of a Current-Source Thermoelectric Power Generator and Its Corresponding Structure Design

Traditional thermoelectric power generators consist of thermoelectric elements connected electrically in series and thermally in parallel. Current flowing inside the thermoelectric power generator is conventionally considered to be driven by the Seebeck effect-induced electric field and the output voltage-induced reverse electric field. This paper proposes a more comprehensive model that implies that current is also driven by chemical potential and carrier density variation. Therefore, the thermoelectric power generator can be treated as a current-source power supplier when the current driven by carrier density variation dominates. This paper performs holistic finite element implementation of the new holistic model where a thermoelectric power generator unit behaves like a current-source while the working temperature conditions maintain stability. This result validates that the thermoelectric element shows the behaviors of a current-source power supply under certain conditions. This discovery brings a new perspective on the behaviors of thermoelectric elements, which potentially will lead to the development of novel thermoelectric power generator design.

Current-Fed High-Frequency AC Distributed Power System for Medium–High-Voltage Gate Driving Applications

A current-fed high-frequency alternating-current (HFAC) distributed power system is presented in this paper for medium- or high-voltage gate driving applications. The distributed gate driving modules (GDMs) at the high-voltage side are isolated from the low-voltage-side current-source power supply through magnetic coupling of current transformers (CTs), which are assembled by a high-voltage cable carrying HFAC and passing through the center of toroid magnetic cores. The centralized high-frequency current-source power supply is designed and composed of a two-stage resonant inverter and a double $\Gamma$ -CL resonant network. The resonant network is parameterized by considering the tradeoff between the quality factor and component stress. Different magnetic core samples are tested and compared to construct the CTs for improving transmission efficiency. A 400-W prototype was built and experimentally evaluated with two load conditions, including resistive loads and practical GDMs. It showed significant improvements with regard to sinusoidal current output, system stability, and efficiency. Finally, the proposed current-fed HFAC power supply system was successfully applied to a practical solid-state fault current limiter, demonstrating the advantages of multiple outputs ( $n >$ 10), high-voltage isolation, low harmonic distortion, high efficiency, easy installation, and flexible extensibility.

Analysis and Design of an LCL-T Resonant Converter as a Constant-Current Power Supply

An LCL-T resonant converter (LCL-T RC) is shown to behave as a current source when operated at resonant frequency. A detailed analysis of the LCL-T RC for this property is presented. Closed-form expressions for converter gain, component stresses, and the condition for converter design optimized for minimum size of resonant network is derived. A design procedure is illustrated with a prototype 200-W 20-A current-source power supply and experimental results are presented. The LCL-T RC as a current source offers many advantages such as easy parallel operation and low circulating currents at light load. Additionally, with appropriate phase shift in paralleled modules, the peak-peak ripple in output current is reduced and the ripple frequency is increased, reducing filtering requirements. The leakage inductance of a transformer can be advantageously integrated into the resonant network. These merits make the topology applicable in various applications such as magnet power supply, capacitor charging power supply, laser diode drivers, etc.

Superconducting linear synchronous motor tests

We have tested a large superconducting linear synchronous motor designed for high-speed magnetically levitated vehicles. A single superconducting magnet, from the array of 45 carried by the proposed vehicle, interacts with guideway windings mounted on the rim of a 7.6 m diameter rotating wheel. The split 3-phase "stator" windings are energized from a variable-frequency 40 kVA current-source inverter power supply. All forces and torques developed on the magnet have been monitored over the complete 360° cycle of force angle for a range of suspension heights, lateral displacements, and pitch, roll and yaw angles, at speeds up to 100 km/h. Controlled starting, stopping and section entry have been demonstrated. The results are in excellent agreement with analysis based on mutual inductance computations and on a coupled circuit model of the machine. Highlights of the results are discussed.