Design of a 300-W Isolated Power Supply for Ultrafast Tracking Converters
TL;DR: In this article, the authors presented a medium power-rating isolated power supply for ultrafast tracking converters and MOS-gate driver circuits in medium and high voltage applications, which maximizes its immunity from noise due to fast changes in voltage.
Abstract: This paper presents the design of a medium-power-rating isolated power supply for ultrafast tracking converters and MOS-gate driver circuits in medium- and high-voltage applications. The key feature of the design is its very low circuit input-to-output parasitic capacitance, which maximizes its immunity from noise due to fast changes in voltage. The converter is a voltage-controlled current source, utilizing a transformer with extremely low interwinding parasitic capacitance, which is achieved by separating the windings by a significant distance. Experimental measurements show that an overall circuit input-to-output parasitic capacitance of 10 pF in a 300-W prototype can be achieved. The circuit input-to-output capacitance per watt is therefore 30 times lower than that of existing approaches. A mathematical model of the interwinding capacitance of the proposed transformer, circuit analysis, and experimental results are provided to prove the feasibility of the converter.
Citations
More filters
TL;DR: A novel non-Y-capacitor EMI design concept for SMPS is proposed for the first time and optimized transformer architecture is presented, demonstrating the effectiveness and feasibility of the proposed non- Y-Capacitor design schemes.
Abstract: In order to construct a low-impedance loop for common-mode electromagnetic interference (EMI) signals, traditional method is to use Y-capacitors as filtering components. However, in the commonly used isolated ac-dc switching-mode power supplies (SMPS), the Y-capacitors branch also behaves as a terrible leakage current loop. For the safety of human beings, this leakage current is not allowed in commercial used equipment, such as chargers, medical instruments, etc. Therefore, certain works should be done to both acquire good EMI performance and satisfy the strict leakage current limitation. The goal of this paper is try to meet these two demands at the same time. In this paper, a novel non-Y-capacitor EMI design concept for SMPS is proposed for the first time. By getting rid of traditional EMI filtering component-the Y-capacitors, the leakage current can be eliminated entirely. Meanwhile, to face with EMI design challenge, optimized transformer architecture is presented. Analysis of the transformer architecture as well as the auxiliary winding has been carried out. Then, a novel topology suitable for non-Y-capacitors converter is proposed and the design procedure of the proposed topology is discussed in detail. The proposed concept is applied to several popular converter topologies. The experiment results demonstrated the effectiveness and feasibility of the proposed non-Y-capacitor design schemes.
37 citations
TL;DR: A novel isolated gate driver power supply using high-frequency wireless power transfer (WPT) with a nonoverlapped winding arrangement for a small coupling capacitance is proposed and a grounded shield is added to further reduce the effective coupling capacitors and the CM current.
Abstract: A high-voltage operation and breakneck switching speed of medium-voltage (MV) silicon carbide (SiC) devices demand gate drivers (GDs) with high voltage withstanding capability, high common-mode (CM) transient immunity and a reliable short-circuit protection. An isolated GD to meet these challenging requirements is presented in this article. A novel isolated gate driver power supply using high-frequency wireless power transfer (WPT) with a nonoverlapped winding arrangement for a small coupling capacitance is proposed. Moreover, a grounded shield is added to further reduce the effective coupling capacitance and the CM current. The receiver (Rx) coil of the WPT system along with its power processing circuit have been epoxy encapsulated to achieve a very high breakdown voltage and an extremely small form factor without violating very demanding clearance and creepage distance requirements. The impact of epoxy, winding arrangement, Rx circuits, and the grounded shield on the coupling capacitance is analyzed in details. In addition, a sophisticated overcurrent protection (OCP) scheme with soft-turn- off capability for MV SiC devices is developed. The designed OCP scheme achieves fast protection and simultaneously avoids false tripping due to very high current overshoot associated with the MV SiC devices during turn- on transitions. An experimental prototype is developed and the performance of the proposed GD under various operating conditions is evaluated experimentally.
26 citations
TL;DR: In this paper, a high-bandwidth NSE emulator is developed that is able to simulate the behaviors of a typical nonlinear source under different critical conditions that can happen during their operations.
Abstract: As research and development of renewable and clean energy based systems is advancing rapidly, the nonlinear source emulator (NSE) is becoming very essential for testing of maximum power point trackers or downstream converters. Renewable and clean energy sources play important roles in both terrestrial and nonterrestrial applications. However, most existing NSEs have only been concerned with simulating energy sources in terrestrial applications, which may not be fast enough for testing of nonterrestrial applications. In this paper, a high-bandwidth NSE is developed that is able to simulate the behaviors of a typical nonlinear source under different critical conditions that can happen during their operations. The proposed 200-W NSE, which consists of a fourth-order output filter buck converter and a novel nonlinear small-signal reference generator, can quickly react not only to an instantaneous change in the input source but also to a load step between nominal and open circuit. Moreover, all of these operation modes have a very fast settling time of only 10 $\mu$ s, which is hundreds of times faster than that of existing works. This attribute allows for higher speed and a more efficient maximum power point tracking algorithm. The proposed NSE, therefore, offers a superior dynamic performance among devices of the same kind.
18 citations
TL;DR: An evaluation method to measure the equivalent CM noise capacitance of the two main CM current conduction paths and a CM noise cancellation scheme based on the transformer winding design is proposed combining the measurement technique and the FEM simulation tool.
Abstract: Common-mode (CM) conduction electromagnetic interference (EMI) is a challenge for switched-mode power supply (SMPS) designers. A flyback converter is a traditional topology used in low-power isolated applications. The size and cost of EMI filters are important considerations for higher power density and lower cost of SMPS design. In most cases, the CM current is generated by voltage pulsation (dv/dt) assigned on the primary winding and the secondary winding. The CM current conduction paths can be mainly categorized into two categories. One is the interwinding parasitic capacitance of the transformer, and the other is the parasitic capacitance between the semiconductor switches and the protective ground. This paper proposed an evaluation method to measure the equivalent CM noise capacitance of the two main CM current conduction paths, respectively. Then, this paper proposed a CM noise cancellation scheme based on the transformer winding design combining the measurement technique and the FEM simulation tool. Planar transformers with PCB windings also have advantages in low profile, good heat dissipation, and good stray parameter consistency. Based on these considerations, an 18-W adapter is designed and tested to verify the effectiveness of the proposed evaluation method and the design scheme.
11 citations
01 Jun 2021
TL;DR: A unified fast-dynamic direct-current (FDDC) control scheme is proposed for improving the dynamic performance of these I2ACL isolated dc-dc converters and the specialized design principles of the PI parameters in the unified FDDC control method are presented.
Abstract: The isolated dc-dc converters with middle inductive AC links dc-dc converter have been extensively studied in modern energy conversion applications for safety and reliability, especially those featuring intermediary inductive ac-link (I2ACL) configurations such as full-bridge dc-dc converter and dual-active-bridge (DAB). However, up to now, the dynamic equivalence in these I2ACL type converters has not been systematically revealed. To fill such a gap, in this paper, the existing I2ACL isolated dc-dc converters are reviewed thoroughly, including unidirectional type and bidirectional type. Then, the general current transferred features of these two groups are analyzed, respectively, and the transferred current during the transient process is just influenced by the middle inductance little. So, the I2ACL isolated dc-dc converter can be regarded as the first-order converter. Based on the discovered general characteristic, a unified fast-dynamic direct-current (FDDC) control scheme is proposed for improving the dynamic performance of these I2ACL isolated dc-dc converters. Such a scheme can also facilitate the uniform control design for existing or emerging new topologies with the same electrical equivalence. Moreover, the specialized design principles of the PI parameters in the unified FDDC control method are also presented. Finally, to verify the universality and feasibility of the proposed general FDDC control strategy, both simulation and experiment results are presented with demonstration examples, e.g., full-bridge type, DAB-type, and the three-phase DAB type dc-dc converters.
6 citations
Cites methods from "Design of a 300-W Isolated Power Su..."
...According to the voltage value, the two-level I2ACL isolated dc-dc converter and the three-level I2ACL isolated dc-dc converter can be employed in some low voltage conditions [33], [35], [42], [47]....
[...]
References
More filters
TL;DR: An improved interleaving structure with optimal behaviors is proposed, which constructs the top layer paralleling with the bottom layer and then in series with the other turns of the primary, so that a lower magnetomotive force ratio m can be obtained, as well as minimized ac resistance, leakage inductance, and even stray capacitance.
Abstract: The trend toward high power density, high operating frequency, and low profile in power converters has exposed a number of limitations in the use of conventional wire-wound magnetic component structures. A planar magnetic is a low-profile transformer or inductor utilizing planar windings, instead of the traditional windings made of Cu wires. In this paper, the most important factors for planar transformer (PT) design including winding loss, core loss, leakage inductance, and stray capacitance have individually been investigated. The tradeoffs among these factors have to be analyzed in order to achieve optimal parameters. Combined with an application, four typical winding arrangements have been compared to illustrate their advantages and disadvantages. An improved interleaving structure with optimal behaviors is proposed, which constructs the top layer paralleling with the bottom layer and then in series with the other turns of the primary, so that a lower magnetomotive force ratio m can be obtained, as well as minimized ac resistance, leakage inductance, and even stray capacitance. A 1.2-kW full-bridge dc-dc converter prototype employing the improved PT structure has been constructed, over 96% efficiency is achieved, and a 2.7% improvement, compared with the noninterleaving structure, is obtained.
295 citations
"Design of a 300-W Isolated Power Su..." refers background or methods in this paper
...Subjected to high-voltage stresses, the interwinding capacitance causes leakage currents and consequently contributes to the EMI problem [28]....
[...]
...The static capacitance between the inner primary turns and the secondary turns can be expressed as [28], [30]...
[...]
...The interwinding capacitance can be calculated by using the stored electric energy method [28]–[33], in which voltage distribution plays a vital role....
[...]
TL;DR: In this paper, the authors present a comprehensive procedure for calculating all contributions to the self-capacitance of high-voltage transformers and provide a detailed analysis of the problem, based on a physical approach.
Abstract: The calculation of a transformer's parasitics, such as its self capacitance, is fundamental for predicting the frequency behavior of the device, reducing this capacitance value and moreover for more advanced aims of capacitance integration and cancellation. This paper presents a comprehensive procedure for calculating all contributions to the self-capacitance of high-voltage transformers and provides a detailed analysis of the problem, based on a physical approach. The advantages of the analytical formulation of the problem rather than a finite element method analysis are discussed. The approach and formulas presented in this paper can also be used for other wound components rather than just step-up transformers. Finally, analytical and experimental results are presented for three different high-voltage transformer architectures.
255 citations
"Design of a 300-W Isolated Power Su..." refers background in this paper
...The static capacitance between the inner primary turns and the secondary turns can be expressed as [28], [30]...
[...]
TL;DR: In this paper, the two-port network approach and the step-response approach are used for determining stray capacitances in a two-winding high frequency transformer for circuit simulation and computeraided design purposes.
Abstract: This paper presents practical techniques for determining stray capacitances in a two-winding high frequency transformer for circuit simulation and computer-aided design purposes. These techniques fall into two categories: The two-port network approach; and the step-response approach. The first approach can be employed for high frequency transformer circuit models with the effect of stray capacitances modeled as a /spl pi/-shape network of three lumped stray capacitances. The second approach is useful for the transformer circuit model with the overall effects of stray capacitances modeled as lumped stray-capacitance connected cross the primary side. These techniques have been verified in the modeling and numerical simulation of a 500 W 25 kHz two winding E-core transformer. The merits and limitations of these techniques are also discussed.
200 citations
24 Oct 2005
TL;DR: A new simple procedure for modeling parasitic capacitances that is based on the known approaches is proposed and the resulting equations are verified by measurements on four different high voltage transformers.
Abstract: Parasitic capacitances of conventional transformers can be used as resonant elements in resonant DC-DC converters in order to reduce the overall system size. For predicting the values of the parasitic capacitors without building the transformer different approaches for calculating these capacitances are compared. A systematic summary of the known approaches is given and missing links between the different theories and missing equations are added. Furthermore, a new simple procedure for modelling parasitic capacitances which is based on the known approaches is proposed. The resulting equations are verified by measurements on four different high voltage transformers.
199 citations
TL;DR: In this paper, a general balance concept is proposed to cancel the common mode noise, and the theoretical analysis, simulation, and experiment prove that the proposed balance technique is efficient enough to reduce common mode noises.
Abstract: In this paper, the boost converter model for electromagnetic interference noise analysis is first investigated. Based on this model, a general balance concept is proposed to cancel the common mode noise. Theoretical analysis, simulation, and experiment prove that the proposed balance technique is efficient enough to reduce common mode noise.
169 citations