Abstract:In this paper, first the operating principles of a non-isolated universal bidirectional DC-DC converter are studied and analyzed. The presented power converter is capable of operating in all power transferring directions in buck/boost modes. Zero voltage switching can be achieved for all the power switches through proper modulation strategy design, therefore, the presented converter can achieve high efficiency. To further improve the efficiency, the relationship between the phase-shift angle and the overall system efficiency is analyzed in detail, an adaptive phase-shift (APS) control method which determines the phase-shift value between gating signals according to the load level is then proposed. As the modulation strategy is a software-based solution, there is no requirement for additional circuits, therefore, it can be implemented easily and instability and noise susceptibility problems can be reduced. To validate the correctness and the effectiveness of the proposed method, a 300 W prototyping circuit is implemented and tested. A low cost dsPIC33FJ16GS502 digital signal controller is adopted in this paper to realize the power flow control, DC-bus voltage regulation and APS control. According to the experimental results, a 12.2% efficiency improvement at light load and 4.0% efficiency improvement at half load can be achieved.
In Taiwan light source (TLS), Bira’s MCOR30 power converter modules are adopted as the corrector magnet power converters, the output is regulated by analog PWM IC that caused nonlinear behavior at zero cross and the adjustment of compensator for different kind of magnet load is inconvenient. To fulfill digital regulation control, the analog regulation IC of Bira’s MCOR30 is replaced by a fully digital regulation control circuit. With plugging the homemade fully digital regulation control card into MCOR30 that the current sensing component is a shunt that save cost of the power converter, the switching losses and output current ripple were reduced and stability of output current is improved. With the fully digital regulation control circuit, the parameters of the compensator for different magnet load are very easy to adjust. In addition, the feasibility and validity of MOSFET switching algorism is simulated with MATLAB Simulink and the performance of this power converter is verified, the output current ripple of this power converter could be within 10ppm, which is beyond the requirement of current TLS corrector power converter and qualified to be used in the future TPS facility.
Using software builda three-dimension simulation model of theTPS power supplies cable engineering. The civil engineering of TPS (Taiwan Photon Source) will soon be completed. The powersupply cables engineering should be done before the scheduled completion of the civil engineering. To use software (SolidWorks) to build a three-dimensionalcabling simulation model, we obtain detailed cablinginformation because the model is made to scale, 1 to 1. As all components are built into the model of the TPS accelerator, we can build accurately a model of the powersupply cabling project. For example, we can check the position for every cable. We also canestimate every length and the total cable length for purchase and budget control. As we can evaluate the conditions for every power cable to lay the cable tray from the power supply to the magnets, we can lay every cable to follow the sequence in the cable tray. We thereby convert the drawing of the two-dimensional construction graph when we design the finished three-dimensional cabling simulation model. The precise and excellent results are proved in this paper.
We designed and implemented a power converter to provide a dc power bus for the MCOR 12 correction supply. The characteristics of the dc power bus are variable frequency at both heavy and medium or light loads. These characteristics match the working requirement of the correction supply. The dc power bus has a relaxation oscillator that generates a symmetric triangular waveform, to which MOSFET switching is locked. The frequency of this waveform is related to a voltage to be modulated with feedback circuitry. As a result, the circuit and complex transformer are driven with a half-bridge. We designed the complex resonant transformer and describe in this paper a simulation model that is highly important, thus to exploit its frequency-dependent transfer characteristics. We obtained a power bus with small ripple to provide the correction power. The high-performance characteristics of the resonant dc power bus are illustrated in this paper.
The energy conversion and the step-down voltage waveform of apiezo transformer are required to achieve an optimal working condition of the resonant frequency. To fulfill this requirement, a reliable and precise instrument is needed to scan the resonant point of the piezo transformer such that its output power performance can conform to the required specification. This paper describes the design and modeling of a new step-down piezo transformer deployed in NSRRC. This transformer is capable of delivering energy conversion with a highly efficient performance, better than that of a traditional transformer, and the voltage transfer ratio is correct. Use ofa simulation circuit model to develop its driver circuit is included in the design of this new step-down transformer. It has been tested and proved to work satisfactorily in power conversion with excellent efficiency and reliability.
The correction power supplies are working in the Taiwan Photon Source (TPS) of NSRRC. They are required to output current at high quality and with high performance and that has long-term stability, with output current ripple required to be less than 10ppm. The TPS comprises more than 1200 units of independent power-supplymodules working together when the beam current is at3-GeV status. The power supplies are all working in current mode. We willplan to build a new measurement laboratory for conduction Electromagnetic Interference (EMI) to measure and to test the switching DC power bus thatfeeds the correction power supplies. We can get conduction electromagnetic interferencenoise from the measurement equipmentto measure the switching DC power bus is an AC-to-DC voltage bus source.With the LISN obtainingthe conduction noise, it is a high-frequency voltage noise generated by the switching mode of the power-supply conduction noise. The current signal passes an AC source-impedance stabilized network LISN, and a spectrum analyzer obtains the conduction noise. We use a noise separator to separate the common EMI noise and the difference-mode EMI noise for EMI filtering design. The measurement results are illustrated in this paper.
At the Taiwan Light Source (TLS), the booster ring provides energy injection at repetition frequency 10 Hz with injection capability in the top-up mode. To obtain the wide acceleration energy range 50 -- 1.5 GeV, a 'White-circuit' topology has been chosen. The White circuit is, briefly, a biased resonant circuit in which the energy is transferred between the booster bending magnets and a large capacitor bank. The White circuit uses a resonance axiom to ramp the current of the bending magnets. The peak current is 2300 A; the bending magnets can accelerate the energy of the booster electron beam current from 50 MeV to 1.5 GeV with the White circuit system. We analyze the characteristic of the White circuit to get a circuit model. Using the circuit model to simulate impedance and phase are identical with the measurement data of the White circuit. The results are described in this paper.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.