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The Buck converter exhibits interesting nonlinear phenomena which many studies have addressed, and the resonant parametric perturbation is effective to control these nonlinear phenomena. We investigate the control mechanism by using the monodromy matrix derived from the Filippov's method when the perturbation has an appropriate phase shift and the duty ratio is not changed. We find that only one term...
Boost converters are widely used in several applications such as solar PV systems, energy storage systems, etc. In order to improve its dynamic performance, several model predictive control (MPC) strategies have been proposed to govern this DC-DC converter. However, in general, they require long prediction horizons to achieve a stable closed-loop due to its well-known non-minimum phase behavior. A...
Power consumption and device size have been placed at the primary concerns for battery-operated portable applications. Switching converters also known as DC/DC convertors gain popularity in powering portable devices due to their high efficiency, compact sizes and high current delivery capability. Currently, the Synchronous Buck convertor has become much more popular in portable devices due to their...
Modular multilevel converters (MMC) are used in the applications such as medium voltage multi-megawatt drives and in HVDC power transmission. The converter has several sub-modules connected in series that are switched appropriately to regulate the pole voltage. Besides regulation of output voltage, it is also essential to regulate the individual sub-module capacitor voltages. In this paper, a novel...
In this paper, a power module capacitor voltage balancing method is presented for a ±350 kV/ 1000 MW modular multilevel converter (MMC) oriented for a back-to-back grid interconnecting project. In this method, a Balancing Adjusting Number (BAN) is proposed to adjust the voltage balancing effect and the switching frequency of the power modules. An accurate switching frequency calculation method is...
Different modulation techniques used to control multilevel converters can be classified based on the selected converter topology and optimization goals. Among all proposed modulation methods low switching frequency modulation techniques are very popular for multilevel converters yet non-real time low switching frequency methods cannot be applied to multilevel converters with unequal or varying DC...
In order to analyze and calculate the switching frequency of power switches in modular multilevel converter (MMC) quantitatively, a mathematical model for sinusoidal pulse width modulation (SPWM) and nearest level modulation (NLM) is proposed in this paper. The factors influencing the switching frequency are summarized, and the superior and inferior limits in extreme cases of operation are analyzed...
This paper presents a multilevel multistage inverter design and its corresponding control strategy. The hybrid inverter has a high voltage stage composed of the six-switch conventional three phase inverter with its output connected in series with the outputs of three-level H-bridge medium and low voltage stages. The voltage ratio has been selected to enable both one state — approximation and PWM control...
With the increase of switching frequency, dissipation of switching device became one of the most important factors which constrained the efficiency of DC-DC converter. A phase-shifted full-bridge circuit which based on the phase-shifted quasi-resonant converter was introduced in this paper. We developed a switching power supply prototype for 1000W. Some specific circuits, waveforms from the saber...
This paper presents a look-up table based digital control approach to on-line efficiency optimization over wide ranges of operating conditions. The proposed digital controller allows programmable modes of operation based on off-line efficiency characterization and optimization. Applied to a flyback dc-dc converter, the controller adopts valley switching in discontinuous conduction mode (DCM), which...
Minimization of the dc capacitor is an essential step towards developing and manufacturing compact low-cost hybrid electric vehicle (HEV) converter/inverter systems for high temperature operation, long life and high reliability. Previously, most papers have been focused on the AC-DC-AC pulse-width modulation (PWM) converters with relatively complicated close-loop control methods, while few papers...
This paper reports the implementation of high voltage step-up converters in standard 130nm 1.2V CMOS technology. Two hybrid boost converters have been fabricated and are compared, each of which are enabled by the development of enhanced high voltage devices for the standard process: Schottky diodes and stacked NMOS switches. Each device can sustain blocking voltages near 10V or greater in the 1.2V...
One of the most important aims in the electronic industry is the reduction of the size of the magnetic components, since it allows the improvement on the power density and the decrease in the cost of the power electronics equipment. In this paper, the chopped sinusoid peak current control scheme in critical conduction mode (CRM) PFC converter is proposed to reduce the inductance and the peak inductor...
Methods and a circuit implementation of audible noise reduction in switch-mode converters with variable switching frequency are presented. The audible noise caused by magnetic components is reduced by controlling the switching frequency so that it stays above the audible range as the load decreases. This is accomplished by decreasing the peak value of the main switch current pulses in discrete steps...
In this paper, a new zero-voltage-switching high power-factor (PF) rectifier with Line-Modulated Fixed-Off-Time current control is introduced, that off time is a function of the instantaneous line voltage. The auxiliary circuit provides soft switching for all semiconductor devices, without any extra current and voltage stress on the main switches. The proposed converter is bridgeless, and all semiconductor...
Buck regulators are widely employed in portable devices due to their high power-conversion efficiency. However, due to their spurious output noise, they are not directly used to power sensitive analog/RF modules, and subsequent linear low-dropout regulators (LDOs) are needed to generate secondary low-noise supply rails for these modules. This results in lower efficiency, and increased size and cost...
Cascaded H-bridge multilevel inverter topology is one of the most popular topologies in high voltage applications. This topology uses multiple units of H-bridge power cells connected in series chain to produce AC voltage. Multilevel inverters have other topologies that can be used according to condition and demand. Pulse width modulation is a popular method to control Cascaded H-bridge inverters....
In this paper a sliding mode controller is proposed for a continuous current mode buck converter. High proficiency and simplicity of implementation are the most significant features of the proposed controller. To fix the switching frequency of the converter, the sign function which generates the discontinuous control law in sliding mode controller, is replaced with a hysteresis relay whose cycle is...
This work introduces a set of PWM SEPIC dc-dc converters specially designed for high voltage-gain conversion, the voltage gain in the proposed converters can be adjusted by PWM and by adding diodes and capacitors in a diode-capacitor multiplier structure. They main features are: (i) high-voltage gain, without extreme duty cycles and transformer-less which allow high switching frequency and without...
Traditional EDM power supplies convert the energy at low frequency, directly from the utility line and they are able to deal with a wide spectrum of output power. The EDM power supply must achieve high voltage to generate the spark and large current to maintain the ion column. To achieve this, large and heavy transformers and inductances are required. Resonant converters are desirable for power conversion...
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