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New Class-E DC-DC converter topologies with constant switching frequency

Y.-F. Liu, P.C. Sen

1996
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IEEE transactions on industry applications
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kT < t1 < T and 0 < m < 1. Define m as the current filling factor. After mathematical manipulation, m = 1 = M 2 k R 2fL : From the above equation, we can see that the DCM is caused by the following factors. • Switching frequency f is too low. • Duty cycle k is too small. • Inductance L is too small. • Load resistor R is too big. In the DCM, current i L increases during switch-on and decreases in the period from kT to (1 0 k)mT . The corresponding voltages across L are V I and 0(V C 0 V I ).
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... efore, kT V I = (1 0 k)mT (V C 0 V I ): Hence, Since all C, C1, and CO are large, The voltage transfer gain in the DCM is MDCM = 1 + k 2 (1 0 k) R 2fL : The relation between dc voltage transfer gain M and the normalized load at various k in the DCM is also shown in Fig. 2 (f). We can see that, in DCM, the output voltage increases as the load resistance R is increasing. III. SIMULATION AND EXPERIMENTAL RESULTS OF SELF-LIFT CUK CONVERTER A. Simulation Results Microsim Design Center (including PSPICE) is a standard electronic circuit simulation software package. Using the Design Center 8 (Evaluation Version) to simulate the proposed new dc-dc converters is a helpful method for circuit design. In the simulation, the switch is an NMOS IRF540 and the diode is an MR824. The other parameters are: R = 30 , k = 0:4, C = C 1 = C O = 100 F, and L = L O = 100 H. Input voltage is V I = 30 V. The simulation waveforms are shown in Fig. 3(a) . From the simulation waveforms, we can see that the output voltage is essentially a dc voltage. B. Experimental Results A particular breadboard prototype of the proposed self-lift Cuk converter was constructed. The semiconductor switch S is an NMOS IRFP460. The diode is an MR824. The other parameters are: R = 30-340 , k = 0:1-0.9, C = C O = 100 F, and L = 470 H. Input voltage is V I = 0-30 V. The experimental waveforms shown in Fig. 3(b) are: channel 1 of the oscilloscope is the pulsewidth modulation (PWM) switching signal, and channel 2 is the output voltage. It can be seen that the output voltage is essentially a dc voltage. There are spikes in the switching point because the PWM signal is not ideal and the components are not ideal. IV. CONCLUSIONS This letter has introduced the skills of the voltage lift technique applied in the design of dc-dc converters. A group of new dc-dc step-up (boost) converters-six self-lift converters-has been developed by applying the voltage lift technique. These converters are different from the conventional converters, and have higher output voltage and better characteristics. They will be used in consumer engineering projects and industrial applications. REFERENCES [1] F. L. Luo, "Positive output Luo-converters: Voltage lift technique," Proc. Abstract-Induction machines supplied by power electronic inverters for variable-speed systems are different from those fed directly from a utility power line. The design strategies of induction machines considering power electronic supply are presented and implemented. The proposed approach permits the integration of the design of machines with inverters, comprehensive performance analysis, and system optimization. Index Terms-Induction machine, integration design, inverter drive.

doi:10.1109/28.511655
fatcat:jhnsu5owobgwnhvvkew7zodihe