An experimental model of a 2kw, 2500 volt power converter for ion thrustors using gate controlled switches in two phase-shifted parallel inverters summary report

Power converter for ion thrustors using electronic gate controlled switches in two phase-shifted parallel inverter

Soft-Switched Resonant DC-DC Converter in Underwater DC Power Distribution Network

Power distribution with DC source is advantageous over its AC counterpart in long distance distribution network due to the absence of effects of reactive components. Long distance power distribution with traditional voltage source suffers from drop in voltage over the length of the cable due to its impedance and forces the converters in the network to be over-designed with higher power rating than needed. In underwater power distribution network such as ocean observatory, marine sensors on the sea-bed etc., power conversion modules are situated at a distance far away from the shore, ranging from tens of kilometers to hundreds of kilometers. DC current distribution offers ruggedness against voltage drop over the length of the trunk cable and thus eliminates the need of converter over-design, making it the preferred choice in underwater long distance power distribution network. Moreover, distribution with DC current source improves the overall system reliability with robustness under cable fault scenarios. Converters used in underwater system require operation with high reliability with little to no maintenance due to their geographical locations. Resonant converters offer quiet and efficient operation with low EMI due to low di/dt and dv/dt owing to sinusoidal current and/or voltage and soft-switching. This makes resonant converters an excellent choice for reliable, long term operation in underwater distribution system. However, designing resonant converters with constant current input imposes certain challenges as compared voltage source input, which are analyzed in this work. Addressing these challenges it is shown how different resonant power conversion topologies can be suitably selected and designed to meet the end goal of regulating its output current or voltage for wide range of loads. Soft switching requirements of these topologies are also investigated with appropriate vi solutions to ensure devices used in these converters switch with low loss and dv/dt. Some of the critical loads in the system demand bidirectional power transfer capability which is also presented in this work with befitting topology. Detailed modeling, analysis, design and experimental results from hardware prototypes are presented for all the converters in the system operating with 250 kHz switching frequency, regulating its output voltage or current from 1 A DC current source, up to a power level of 1 kW

Optimization study of high power static inverters and converters Final report

Optimization study and basic performance characteristics for conceptual designs for high power static inverter

Integralni pristup sustavima energetske elektronike

Today\u27s power electronics systems are typically manufactured using non-standard parts, resulting in labor-intensive manufacturing processes, increased cost and poor reliability. As a possible way to overcome these problems, this paper discusses an integrated approach to design and manufacture power electronics systems to improve performance, reliability and cost effectiveness. Addressed in the paper are the technologies being developed for integration of both power supplies and motor drives. These technologies include the planar metalization to eliminate bonding wires, the integration of power passives, the integration of current sensors, the development of power devices to facilitate integration as well as to improve performance, and the integration of necessary CAD tools to address the multidisciplinary aspects of integrated systems. The development of Integrated Power Electronics Modules (IPEMs) is demonstrated for two applications: (1) 1 kW asymmetrical half-bridge DC-DC converter and (2) 1–3 kW motor drive for heating, ventilation and air conditioning (HVAC). Electrical and thermal design tradeoffs of IPEMs and related enabling technologies are described in the paper.Današnji sustavi energetske elektronike se obično proizvode iz nestandardnih dijelova. Posljedica toga je laboratorijska proizvodnja elektroničkih učinskih pretvarača, povećani troškovi i smanjena pouzdanost. Jedan od mogućih načina prevladavanja ovih poteškoća jest integralni pristup projektiranju i proizvodnji sustava energetske elektronike. Posebice se razmatraju tehnologije razvijene za integraciju učinskih krugova i motora. Ove tehnologije uključuju postupke planarne metalizacije za izbjegavanje žičanih vodova, integraciju pasivnih dijelova učinskih krugova, integraciju strujnih senzora, te razvoj takvih poluvodičkih komponenata koje olakšavaju integraciju i poboljšavaju karakteristike uređaja. Pri projektiranju, zbog multidisciplinarnih aspekata integriranih sustava, treba primijeniti nužne CAD alate. Razvoj integriranih modula elektroničkih učinskih pretvarača (engl. integrated power electronics modules, IPEM) ilustriran je na dvije primjene: (1) istosmjerni pretvarač snage 1 kW u asimetričnom polumosnom spoju i (2) elektromotorni pogon snage 1 . . . 3 kW za grijanje, ventilaciju i klimatizaciju (engl. heating, ventilation and air conditioning, HVAC). Na IPEM-u objašnjeni su projektantski i tehnološki kompromisi električkog i toplinskog projekta

접촉 전류와 전자파 방해를 고려한 정전식 절연형 클래스 E 컨버터 설계

학위논문(박사) -- 서울대학교대학원 : 공과대학 전기·정보공학부, 2021.8. 하정익.This dissertation studies a method to reduce the common-mode current in capacitive isolated class E converter. Removing a transformer from a galvanically isolated converter has been researched a lot to design a high power density DC/DC converter. One way to remove the transformer is to use a capacitor instead of a transformer for galvanic isolation. However, using a capacitor increases the common-mode current, which can cause high touch current and conduction EMI (Electromagnetic Interference). Due to a user's safety and compatibility with other electronic devices, all electronic devices' touch current and EMI are strictly regulated. Therefore, methods to reduce a common-mode current in a capacitive isolated DC/DC converter are studied in this dissertation. In this dissertation, common-mode current in the grid frequency band and switching frequency band are analyzed separately. A common-mode current in the grid frequency band is related to touch current, while the switching frequency component of a common-mode current is responsible for conduction EMI. Since grid frequency is relatively low-frequency, the impedance of a capacitor is high at this frequency range. This dissertation, thus, calculates a maximum capacitance allowed to meet the touch current regulation. For DC/DC converter topology, a class E converter is chosen since this topology is suitable for operating in high frequency and reduce the capacitor to block touch current. A balanced class E converter is proposed for lowering the common-mode current in the switching frequency band. The converter's balanced structure can eliminate the common-mode voltage and thus decrease the common-mode current. A common-mode current in class E DC/DC converter with LC series network and T-network is analyzed in this dissertation. T-network is used to set the voltage gain between input and output voltage of the DC/DC converter, and the design method for this network is also written in this dissertation. The common-mode current in a conventional and a balanced class E converter is compared. The effect of parameter error on a common-mode current in a balanced class E converter is also analyzed. Lastly, a self-powered gate driver circuit for providing power to gate drive is presented. Since a high side switch needs to be placed to operate a balanced class E converter, a circuit providing stable power to a gate driver is necessary. Therefore, a self-powered gate driver circuit that can draw power from the voltage across the switch is proposed. Conduction EMI and touch current are measured using 40W 7cm by 3cm converter prototype. From the experiment, the proposed balanced class E converter has lower EMI noise compare to the conventional class E converter. Also, the measured touch current satisfies the regulation ensuring the safety of a proposed capacitive isolated converter.본 논문은 정전식 절연형 클래스 E 컨버터에서 발생하는 공통모드 전류를 분석하고 줄이는 방식을 제안한다. 고전력 밀도의 DC/DC 컨버터 설계를 위해 절연형 컨버터의 변압기를 제거하는 연구가 많이 진행되어 왔다. 변압기를 제거하는 한 방법은 변압기 대신에 커패시터를 이용해 갈바닉 절연을 달성하는 방법이다. 그러나 커패시터를 사용하게 되면 커패시터를 통해 공통모드 전류가 흐르게 되고 이는 접촉 전류와 전도 전자 방해 노이즈를 발생시킨다. 모든 전자기기는 사용자의 안전과 다른 전자기기와의 전자 적합성을 위해 공통모드 전류로 인해 발생하는 접촉 전류와 전도 전자 방해 노이즈를 제한하고 있다. 그러므로 본 논문에서는 정전식 절연형 클래스 E 컨버터에서 발생하는 공통모드 전류를 분석하고 이를 줄이는 방법을 연구한다. 먼저 계통 주파수 대역의 공통모드 전류를 먼저 분석하였다. 이 저주파수 대역의 공통모드 전류는 사용자의 안전을 위협하는 접촉 전류와 관련이 있다. 저주파수 대역에서는 커패시터가 높은 임피던스를 가지기 때문에 최대 커패시터 값을 설정해서 접촉 전류를 규정에 만족하도록 설정할 수 있다. DC/DC 컨버터의 토폴로지로는 클래스 E 컨버터를 선정하였다. 이 토폴로지는 영 전압 스위칭을 통해 고주파 스위칭이 가능하다는 장점이 있어 절연을 위해 사용하는 커패시터 값을 접촉 전류 규정에 맞게 줄일 수가 있다. 전도 전자 방해 노이즈를 발생시키는 고주파의 공통모드 전류를 제거하기 위해서는 컨버터를 대칭형으로 설계하는 방식을 사용한다. 본 논문에서는 LC 직렬 네트워크를 사용하는 정전식 클래스 E 컨버터와 T-네트워크를 사용하는 정전식 클래스 E 컨버터의 공통모드 전류를 분석하였다. 여기서 T-네트워크는 컨버터의 입출력비를 설정할 수 있도록 설계되었고 논문에서 이 네트워크를 설계 방식도 같이 제시하였다. 기존의 클래스 E 컨버터와 대칭형 클래스 E 컨버터의 공통모드 전류를 비교하였고 대칭형 컨버터에서 파라미터 오차에 의한 공통모드 전류도 본 논문에서 분석하였다. 마지막으로 대칭형 클래스 E 컨버터를 설계하기 위해서는 스위치가 상측에 배치되어야 하는데 이를 위해서는 스위치의 게이트 드라이버의 전원을 공급해주는 회로가 추가로 필요하다. 본 논문에서는 스위치에 인가되는 전압을 이용해 게이트 구동기의 전원을 공급해주는 회로를 제시한다. 제안한 컨버터는 40W급의 7cm x 3cm 크기의 프로토타입을 이용해 실험을 진행했다. LC 직렬 네트워크를 사용하는 정전식 절연형 클래스 E 컨버터와 T-네트워크를 사용하는 정전식 절연형 클래스 E 컨버터를 실험했고 접촉 전류와 전도 전자 방해 노이즈를 측정했다. 제안한 정전식 절연형 컨버터가 기존의 컨버터에 비해 전도 전자 방해 노이즈를 감소시킬 수 있었고 접촉 전류 또한 규정에 맞게 제한되어 제안하는 정전식 절연형 컨버터의 안정성을 확인하였다.1. Introduction 1 1.1 Research Background 1 1.2 Research Objective 11 1.3 Thesis Composition 12 2. Capacitive Isolated Converter Design 14 2.1 Modeling of Capacitive Isolated Converter 14 2.2 Grid Frequency Component Analysis 16 2.3 High-Frequency Converter Topology 26 2.3.1 Class E Converter Operation 30 2.3.2 Inverter and Rectifier Voltage Analysis 35 3. Class E Converter with LC Series Network 49 3.1 Common Mode Current in Class E Converter 49 3.2 Common Mode Current in Balanced Class E Converter 59 3.2.1 Common mode filter 72 3.3 Experimental Results 76 4. Class E Converter with T-model Network 83 4.1 Two-port Network Design 83 4.2 Common Mode Current in Class E Converter 100 4.3 Common Mode Current in Balanced Class E Converter 106 4.4 Experimental Result 117 5. Self-powered Gate Driver Circuit 120 6. Conclusion and Future Research 135 6.1 Conclusion 135 6.2 Future Research 138 Appendix 139 A.1 Safety Requirements for Medical Electrical Equipment 139 A.2 Common Mode Current in Class E Converter 143 Reference 146 국문 초록 155박

Bi-directional four quadrant (BDQ4) power converter development

The feasibility for implementation of a concept for direct ac/dc multikilowatt power conversion with bidirectional transfer of energy was investigated. A 10 kHz current carrier was derived directly from a common 60 Hz three phase power system. This carrier was modulated to remove the 360 Hz ripple, inherent in the three phase power supply and then demodulated and processed by a high frequency filter. The resulting dc power was then supplied to a load. The process was implemented without the use of low frequency transformers and filters. This power conversion processes was reversible and can operate in the four quadrants as viewed from any of the two of the converter's ports. Areas of application include: power systems on air and spacecraft; terrestrial traction; integration of solar and wind powered systems with utility networks; HVDC; asynchronous coupling of polyphase networks; heat treatment; industrial machine drives; and power supplies for any use including instrumentation