Wednesday, 27 June 2018 12:10-14:00
Chairperson: Abhijit D. Pathak, International Rectifier, USA
|Application of High-voltage 750V Aluminum Electrolytic Capacitor in Inverter
Kezhuang Yu, Shenzhen Zeasset Electronic Technology Co., Ltd. , China
In the three-phase 380V inverter, 2 pieces 400VDC capacitors in series are usually used. Zeasset succeeds in developing one single aluminum electrolytic capacitor with voltage endurance up to 750VDC to replace them. The replacement enables the reduction of numbers of parallels and series, the simplication of circuit design for users and higher reliability of system.
|Improved Analysis and Modelling of Leakage Inductance for Planar Transformers
Ziwei Ouyang, Technical University of Denmark, Denmark
Planar transformers have often been mistaken to essentially have lower leakage inductances. The “radial effect” is a nature characteristic for planar windings due to a higher aspect ratio of conductor width to conductor thickness, which gives a reduction of leakage inductance. Traditional formulas of leakage inductance calculation for traditional transformers are not well suitable for planar transformers. This paper specifically tailors the previous 1-D solution of leakage inductance calculation, and proposes a new formula with the consideration of both ac (high frequency skin and proximity effect) and dc effects (radial effect). The new formula gives a more accurate prediction of leakage inductance in planar transformers. Finite Element Analysis (FEA) simulation and measurements are carried out to validate the proposed formula.
|A Comprehensive Loss Analysis for Quasi Resonant Flyback Converter with Design Purpose
Halil Alper Onay, Akim Metal San. Ve Tic. A.Ş., Turkey
Flyback converter is a hard switched topology which means that current and voltage signals cross each other during turn-on and turn-off switching transitions and efficiency is relatively low in between 75% to 90% for universal input AC/DC applications. To increase efficiency, quasi resonant switching method is implemented in new generation ICs. However, it is hard to find a practical guide in order to estimate component power losses during design process. For this reason, a comprehensive power loss analysis is investigated for a discontinuous mode quasi resonant flyback converter in this paper. Moreover, design limitations of the topology is examined by changing some conditions of the application that is used. For those purposes, firstly, design procedure of the topology is provided and the required information about the application is obtained. Afterwards, crucial loss items is illustrated on a basic schema and detailed calculations is done by taking practical world conditions into consideration. Right after those calculations, the conditions like frequency, rising time of voltage on the semiconductor switch and output power level is changed and limitations of the design is observed. Evaluation of the results is also discussed at the end of the paper.
|Comparison of Modeling and Analyzing Methods for Magnetic Resonance Wireless Power Transmission System
Jingjing Yang, Fuzhou University, China
The Magnetic Resonance Wireless Power Transmission (WPT) system can be used in portable electronic devices, implantable microelectronic devices, high-power electric vehicles，and so on. Physicists and electrical engineers use Coupled-Mode Theory (CMT) and Lumped Parameter Electrical Circuit Theory (ECT) to design and optimization of the WPT system, respectively. However, a direct comparison between these two approaches is lacking. This paper compares in detail the similarities and differences of CMT and ECT. We present analysis of several important parameters and characteristics two different Magnetic Resonance WPT systems via CMT and ECT. The calculated and measured results show that the CMT is only applicable to the systems with high quality factor (Q) and small mutual coupling (k), and the ECT is applicable to all types of systems. But the CMT can simplify the analysis in multi-coil WPT system compared to the ECT.
First we established the model of the Magnetic Resonance WPT system utilizing CMT and ECT, respectively. Second, we research this system in steady and transient state. In steady state, we obtained the loop currents, the load output power and the power transfer efficiency by solving the difference equations via CMT and ECT. Then we discussed the impedance matching conditions and compared their theoretical calculations expressions. In transient analysis, we utilized both CMT and ECT in researching the dynamics of energy exchange between transmitting and receiving resonant coils. The energy stored in each coil over time is calculated, respectively. Finally, we simulated two kinds of Magnetic Resonance WPT systems with different parameters in PSpice circuit simulator and computed the theoretical equations in MATLAB, in order to compare the accuracy of energy equations derived from CMT and ECT. We also designed and fabricated a 2-coil WPT system. The theoretical calculations have a good agreement with the measured data.
According to the above analyzed results, we found the conclusion that both methods have the same results when the coils have high-Q and small-k. In other conditions, the CMT is not accurate but the ECT is still accurate. In addition, we can calculate all parameters via ECT. But we cannot obtain all expressions of the important parameters like the transmitting and receiving loop currents via the CMT. Because the ECT analyzes the circuits utilizing lumped models, well known Kirchhoff’s current/voltage laws and a method often called reflected load theory that are applied to any sort of circuit analysis. The analysis process of the WPT system with an intermediate resonator coil shows that the CMT can simplify the circuit analysis by reducing the order of the differential equations when the number of coils in the WPT system increases compared to the ECT. The reason is that CMT models each resonant object, the resonant inductors in high-Q and small-k system, with a first-order differential equation, while in the electrical circuit analysis the order of the equations increases by each independent energy storage element not only inductor but also capacitor. Hence, the CMT is helpful in analyzing the transient behavior of complicated WPT system.
|An Improved Magnetic Coupling Resonant Wireless
Charging System for Cell Phones
Binlei Ju, Hefei University of Technology, China
As a new theory put forward in recent years, magnetically coupled resonant
wireless power transfer technology (WPT) has a promising prospect. However, there are still many problems to be solved in practical application, such as low transmission efficiency and large power loss. In this paper, to improved the transmission efficiency of magnetic coupling resonant wireless charging system for cell phones, we use the Litz wire coil and compare the difference between the circuit transmission efficiency of common switch tube and GaN switch tube. The transmitter changes 20V DC output by the adapter into AC, through the half-bridge high-frequency inverter circuit. It uses capacitors and coils in series resonance to transmit the power from transmitter to receiver. Through the filter circuit and LM7805 regulator, the output 5V constant voltage is got, so as to achieve the effect of ordinary charger. The proposed scheme is validated by the simulation results and tested results with a prototype.
|Introduction of temperature protection for a small IPM for home appliances application
Xiaoling Wang, Mitsubishi Electric & electronics (Shanghai) CO., Ltd, China
This paper present the design points of temperature protection for Mitsubishi electric SLIMDIP series of Dual In-line Package intelligent power module (abbr. as DIPIPM) for home appliances application. By adopting high performance 2nd Gen. RC-IGBT chip and optimized package design, SLIMDIP achieved higher performance and lower cost which is a suitable product for home appliances application. For home appliances application, temperature protection is important for the reliable operation of DIPIPM especially for air-conditioner application which may operate in high temperature environment. In this paper, SLIMDIP features, temperature protection circuit design are introduced. Example is given to analyze how to set the temperature protection trip level for SLIMDIP.
|A Novel SVPWM Strategy for High-Frequency Noise Suppression of Dual Three-phase PMSM
Boyuan Zheng, Harbin Institute of Technology, China
High-frequency noise due to high-frequency harmonics is audible to the human ear. Because of the existence of 1-2 plane (harmonic sub-plane), high-frequency harmonics are especially serious for dual three-phase PMSM. The novel SVPWM strategy in this paper can suppress the high-frequency harmonics around the switching frequency and other odd multiples. To remove high-frequency noise, the novel strategy need switching frequency around 10kHz instead of 20kHz under conventional two-vector SVPWM strategy. Therefore, the switching losses are significantly reduced using the novel strategy. The novel strategy has been verified by simulation results.
|Improved Smart Power Module for up to 9kW Industrial Motor Applications
Sangmin Park, ON semiconductor, Korea
This paper introduces the improved 1200V SPM® (Smart Power Module) in DIP package, which is fully optimized and intelligent integrated IGBT inverter modules for up to 9kW motor drive applications. It utilizes 1200V IGBT with the freewheeling diode, and built-in bootstrap diode. HVICs, multi-function LVIC, and built-in thermistor provide good reliable characteristics for the entire system. It also provides technical advantage such as the good thermal performances through DBC(Direct Bonded Copper) substrate. This paper provides an overall description of the improved 1200V SPM® 2 product.
|Research on Software RDC Decoding Algorithm and Conditioning Circuit
Hengyu LI, Institute of Electrical Engineering, Chinese Academy of Sciences, China
In the PMSM control system, it is very important to obtain the accurate rotor pole position of the motor. Resolver is installed to get accurate rotor position information. However, since the resolver output signal is a high-frequency modulated analogue, it is necessary to demodulate and convert the resolver output analog signal using a resolver-to-digital converter (RDC). Special chips have the problems of complex hardware circuit, inability to adjust online, phase lag and expensive price. This paper analysis conditioning circuit based on the principle of resolver, describes a software RDC decoding algorithm based on observer.
|High efficiency 1.5kW 48V-12V DCDC converter with Leadless MOSFET for Mild Hybrid Electric Vehicle
Rui RONG, Infineon Integrated Circuit (Beijing) Co., Ltd., China
The paper present a high efficiency 1.5kW 48-12V DCDC converter with leadless package of MOSFET for Mild Hybrid Electric Vehicles. The power loss of each part was precisely calculated to figure out that the power loss of semiconductor is the main part of total power loss. Especially the SSO8 leadless package MOSFET act a significate role in achieving high efficiency converter design. The efficiency is up to 96.5% with interleave multi-phase synchronous buck topology from experimental result. Even higher efficiency could be achieve with optimized MOSFET selection.
|Analysis of Negative Vce which can be generated in PFC IGBT under the Low Input Voltage Condition
Arnold Lee, ON Semiconductor, South Korea
In medium and high power system, IGBT is used as power switch for PFC block with boot diode. In the case of power MOSFET, there are monolithic anti-parallel diode which is called as body diode. However, IGBT does not have anti-parallel diode. If anti-parallel diode is not used with IGBT, unexpected large negative Vce can be generated at low input voltage condition. Level of negative Vce depends on voltage difference between output and input voltage combine with load inductor and IGBT parasitic capacitance. In this paper, reason of negative Vce generation in PFC IGBT will be explained and recommended prevention method will be presented based on the simulation result.
|Cleaning Requirements for Improved Efficiency and Reliability
Jerry Ji, ZESTRON China, China
This paper details power module applications including qualification tests, failure mechanisms and considerations for cleaning processes. Subsequent to its release, engineered aqueous based cleaning agents have been incorporated into power module manufacturing processes. Several customer case studies highlighting this cleaning alternative and the reliability impact on the process are detailed within this paper.