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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...
In this paper, a novel switching frequency control scheme to track the resonant frequency point (f0) is proposed. First, the synchronous rectifier (SR) gate driving signals are well tuned with proposed universal adaptive SR driving scheme by eliminating the body diode conduction. Then, the novel pulse width locked loop with digital implementation is presented to minimize the pulse width difference...
Cúk Converter operating in discontinuous capacitor voltage mode is an inherent PFC converter in which, unity power factor can be achieved using constant duty cycle and switching frequency. In this paper, a reduced-order switch network modeling technique is applied to Cúk converter operating in DCVM in order to derive small-signal model of the converter assuming a dc voltage source as the input source...
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 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...
An ac voltage regulating system of doubly Salient Electro-magnetic Generator has been performed in this paper. In order to maintain the high voltage 360VDC stable, the dual boost converter with fixed frequency PWM controlled is adopted. Three-phase dual buck inverter was adopted to output 115VAC/400Hz. the generating system configuration, control strategy of dual boost converter and three-phase dual...
In this paper we propose a controlled cross-coupled switched-capacitor based embedded DC-DC buck converter based on non-overlapping rotational time interleaving switching scheme and frequency control regulation. Proposed converter uses low swing internal signals to control half of the switches. In addition to reduction of switching power loss, the low swing control signals help to use smaller switches...
A novel half-bridge LLC DC-DC Resonant Converter for high power DC power supply is presented in this paper. The design consideration of resonant tank circuit paramerters are presented. The DC gain characteristics of the proposed converter is analyzed from its complex DC gain equation. First the performance of the converter is analyzed through simulation. The proposed converter operate with higher...
This paper describes technical solutions to be adopted by Electric Vehicles (EV) battery grid interfaces, in order to get the provision of ancillary services to the grid. The developed solution exploits an EV battery charge control approach based in a grid cooperative response to frequency and/or voltage deviations. To be effective, those cooperative actions must result from both centralized/coordinated...
A review of the state of the art in the sliding-mode control of DC-to-DC switching converters is presented. The method of the equivalent control is illustrated in the design of a two-loop control for the voltage regulation of a buck-boost converter. The theoretical predictions are validated by means of PSIM simulations. Prospective applications of the method reported are also discussed.
This paper deals with a voltage and frequency controller (VFC) of a stand-alone wind energy conversion system using an isolated asynchronous generator (IAG) feeding three-phase four-wire loads. The reference generator currents are estimated using the power balance theory to control the voltage and frequency of IAG system. Two-leg reduced switch integrated voltage source converter (VSC) with a battery...
A varying-frequency control Flyback rectifier for LED driving in Boundary-Conduction Mode (BCM) is presented. Comparing with Discontinuous-Conduction Mode, BCM has the advantages like smaller coupling inductor current, less current stress for circuit component, slight output current ripple, and higher power factor performance. For lower output application circumstance, the boundary conduction mode...
In this paper, a quasi sliding mode controller is proposed to control single phase PFC boost converter. The outer voltage loop is PI control and the sliding mode control is used in the inner current loop. The designed quasi sliding mode controller has advantages such as robustness when there are large variations in line voltage and output load. Moreover, the chosen sliding surface avoid the differentiator...
A novel constant on-time bi-frequency (COT-BF) control technique for switching dc-dc converters operating in discontinuous conduction mode (DCM) is proposed in this paper. The proposed COT-BF control technique realizes the output voltage regulation of switching dc-dc converters by adjusting the combination of high-frequency control pulse and low-frequency control pulse. COT-BF control technique is...
This paper proposes a novel soft-switching two-phase boost converter to behave as a power factor correction pre-regulator. This regulator is able to turn on both the active power switches at zero voltage to reduce their switching losses and evidently raise the conversion efficiency. The two boost converters are identical, and their operation analysis and design for the regulator become quite simple...
The paper deals with problems of electromagnetic compatibility (EMC) of frequency control drive of electromotive switch actuator of railway switch. The frequency converter with Pulse Width Modulation (PWM) and the output sinus filter are used for feeding of the asynchronous motor of the switch actuator. This drive is operated in isolated system of feeding voltages. The drive is fed by frequency converter...
This paper presents a capacitor current based adaptive hysteresis controlled DC-DC converter. This controller avoids wide range frequency band filter or complicated compensation. Based on that capacitor current reflects the load current directly and fast, the proposed system uses a simple analog differentiator to sense the voltage capacitor current. Meanwhile, a PI compensation loop is added to improve...
For a zero-voltage switching (ZVS) synchronous boost converter, the power stage efficiency undergoes significant limitation when the load is outside the ideal range. In order to achieve optimum efficiency at a range of load conditions, the magnitude of the resonant current must be controlled. The most effective method to control resonant current is to adjust the converter's switching frequency. Though...
A green-mode power converter is implemented in 0.13 ??m CMOS and achieves step-up/down variable output with adaptively optimized efficiency. Single-bound hysteresis control enables high-frequency switching regulation with suppressed error and noise. For Vm = 1.5 V and fs = 10 MHz, the output is regulated from 0.9 to 2.2 V with an efficiency of >80% over a 400 mW power range.
A development of a rig that demonstrates a load control scheme which provides primary frequency response is reported. The rig uses a commercially available smart meter and remotely controlled smart sockets. A load controller implemented in a computer sends control signals to switch smart sockets on and off. The meter communicates with the computer using Modbus protocol through RS485 - RS232 protocol...
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