This paper presents a control method which combines sliding mode approach of direct power control and operates with constant switching frequency. This novel scheme Sliding Mode Constant Switching Frequency Direct Power Control (SM-CSF-DPC) employs a nonlinear sliding mode control (SMC) approach to directly calculate the required converter’s control voltage. The constant switching frequency (CSF...

Novel 3-level GTO inverter topology is presented. This new power circuit includes many advantages comparing with the conventional 3-level GTO inverter. The main advantages are snubberless and good device utilization by employing dual quasi-resonant dc-link which guarantees the complete zero voltage switching of the inverter GTO's. This 3-level GTO inverter can be operated with lower switching l...

This paper describes a new design for direct sliding mode method with a high switching frequency using the PD-PI type sliding surface applied to a negative output Luo converter worked in continuous current mode for applications required constant power source such as aerospace applications, medical equipment and etc. Because of the output power and line changes, the converter model is also nonli...

The present-day and potential benefits of highly integrated miniaturized applications like wireless micro-sensors and biomedical implants in military, space, medical, and commercial markets fuel the demand for self-sustaining micro-electronic systems. Extending operational life to practical levels in such volume-constrained environments is difficult because space limits energy and power. Althou...

This paper presents considerations on the switching frequency and duty cycle & operating equations of softswitching BUCK chopper. These considerations are discussed and applied to selected soft-switching families such as ZVS-QRC, ZCS-QRC, ZVS-QSW-CV, ZCS-QSWCC, ZVT-PWM and ZCT-PWM [1]. The limitations on switching frequency and duty cycle are derived in terms of: chopper input voltage (Vg), cho...

Two generic configurations of forced commutated PWM converters, i.e. voltage source inverters and current source inverters, have been proposed as advanced reactive power compensators'. A new configuration to combine the features of the two generic ones is proposed, designed and analyzed in this paper. It is composed of a PWM current source inverter handling high power with very low switching fr...

-This paper analyzes a high-power (50 kW) high frequency (150 kHz) voltage-fed inverter with a seriesresonant load circuit for industrial induction heating applications, which is characterized by a full bridge inverter made of insulated-gate bipolar transistor and a power control based on pulse density modulation (PDM). This power control strategy allows the inverter to work close to the resona...

An additional independent control needed to eliminate the undesirable variable switching frequency of quasi-resonant converters can be obtained if the output rectifier is replaced by an active switch. The concept is applicable to all classes of quasi-resonant converters. It is demonstrated that in addition to operation at constant switching frequency, selected classes of constant-frequency quas...

A scheme of frequency hopping spread spectrum (FHSS) frequency synthesizer suitable for synthesis of radio-frequency (RF) carrier signal in very high frequency (VHF) band is proposed, implemented and tested. The synthesizer is based on the direct digital frequency synthesis (DDFS or DDS) and phase locked loop (PLL) with dynamic monitoring of varicap’s voltage to reduce switching time. The resul...

We present ultrafast optical switching experiments on three-dimensional photonic band gap crystals. Switching the Si inverse opal is achieved by optically exciting free carriers by a two-photon process. We probe reflectivity in the frequency range of second order Bragg diffraction where the photonic band gap is predicted. We find good experimental switching conditions for free-carrier plasma fr...