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This paper presents the interleaved operation of a soft-switching boost converter operated in boundary conduction mode. First, the operating principle of the converter as well as the basic concept of the interleaving is presented. Then, the dynamic behavior is modeled using the z-transform to obtain a converter model that is independent of the switching frequency. With the model, the stability of the closed-loop system with a proportional–integral (PI) controller is analyzed. It is shown that an adaptive PI controller can be easily implemented to achieve a minimal settling time over a wide operating range. Finally, the controller is validated with two converters with a 40-kW nominal output power and an output voltage of 3 kV. The tests at different output voltages under different load conditions show a stable interleaved operation. [ABSTRACT FROM PUBLISHER]

Medium and high beta cavities used in linear colliders or spallation sources are supplied by klystrons or inductive output tubes amplifiers. The cathode voltage for these amplifiers can be generated by long-pulse modulators generating highly accurate high voltage pulses in the length of milliseconds. With existing modulator topologies, all the demanding requirements like fast pulse rise time, high accuracy, and low voltage ripple hardly can be satisfied at the same time. Common designs like bouncer modulator topologies using pulse transformers become huge for long pulses. The series–parallel resonant converter (SPRC) avoids this drawback as the transformer is operated at high frequencies. In this paper, the comprehensive multidomain model of an SPRC including an electrical model of the inverter, a magnetic model, and an isolation design procedure of the transformer is verified with a prototype of a single module operated under full-load conditions. In addition, a comparison between the predicted parasitics like leakage inductance and stray capacitance of the transformer and the measured values are given. An evaluation of the isolation of the transformer, which is especially crucial for a series connection of the modules, is also performed. In addition, different possibilities to realize the desired series inductance are discussed. [ABSTRACT FROM PUBLISHER]

In this paper, limitations of compact and durable solid state modulators, using a 4.5-kV IGBT in combination with a pulse compression (PC) circuit are evaluated. Two investigated modulators uses two separate paths: one for ignition voltage and one for high currents. In the first modulator, ignition voltage is generated with a PC circuit based on saturable transformers, which is used to charge a series capacitor. After saturation, the capacitor is connected to the output. The second modulator combines together pulse transformer and magnetic switch. Parasitics have been estimated to find the optimal modulator configuration. Measurement results for validating the models as well as the simulation results are presented. Main limitation factors are described and possible solutions are discussed. [ABSTRACT FROM PUBLISHER]

Switching devices based on SiC offer outstanding performance with respect to operating frequency, junction temperature, and conduction losses enabling significant improvement of the performance of converter systems. There, the cascode consisting of a MOSFET and a JFET has additionally the advantage of being a normally off device and offering a simple control via the gate of the MOSFET. Without dv /dt-control, however, the transients for hard commutation reach values of up to 45kV/\mus, which could lead to electromagnetic interference problems. Especially in drive systems, problems could occur, which are related to earth currents (bearing currents) due to parasitic capacitances. Therefore, new dv/d t-control methods for the SiC JFET/Si MOSFET cascode as well as measurement results are presented in this paper. Based on this new concepts, the outstanding performance of the SiC devices can be fully utilized without impairing electromagnetic compatibility. [ABSTRACT FROM AUTHOR]