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High switching frequencies (several MHz) allow the integration of low power DC/DC converters. Although, in theory, a high switching frequency would make possible to implement a conventional voltage mode control with very high bandwidth, in practice, parasitic effects and robustness make very complex to achieve bandwidths higher than 1MHz. This paper proposes a fast control technique to optimize the...
The interaction between the loads and grid impedances can cause deleterious effects on the dynamic model of shunt active power filters (SAPF). These effects may lead to instabilities on the control system, specially if the loads vary randomically. These side effects could be minimized if SAP F employs a robust control strategy which controller gains are adjusted by adaptation. To overcome these side...
Recently, there has been increasing interest in the parallel operation of DC-DC converters for reasons of increasing system reliability, facilitating system maintenance, allowing for future expansion, and reducing system design cost. In order to achieve desirable characteristics when operating converter modules in parallel, this paper proposes a unified systematic approach for modeling of parallel...
The increasing penetration of generation power plants based on renewable energies in the electrical networks has boosted the number of systems connected to the grid. In this scenario the microgrid, providing advanced functionalities to improve the stability and operation of the network, have become very popular. In this paper a control strategy for the microgrid management is presented. The proposed...
This paper proposes an analysis of the impact of five different synchronization methods on the performance of the compensation currents generated by shunt active filters. The discrete model of shunt active filter is presented considering its implementation in a DSP. Furthermore, two control loops are used to perform the control, an external loop to regulate dc-link voltage that uses a servo system...
The design of the voltage loop and current loop of three-phase high power factor PWM rectifier was introduced, the strategy of dual-mode control that combine fuzzy control to PI regulator is proposed, which use fuzzy controller to obtain quick dynamic response when deviation is in small range and adopt PI regulator to realize no static error when deviation is in long range, improving the control accuracy...
A two stages robust Generalized PI feedback controller for a single-phase active multilevel rectifier is proposed. The controller is based on the system modeled in the d-q synchronous reference frame. Based on input-output linearization theory a current controller that decouples the d-q components and compensates unknown perturbations is obtained. Performing a transformation of the system, stability...
A control scheme constituted by a nonlinear state feedback current controller and a PI voltage controller for a single-phase active multilevel rectifier is designed. The control is based on the system modeled in the d-q synchronous reference frame. Through input-output linearization theory a current controller that decouples the d-q components is obtained. Stability of zero dynamics is verified. Due...
A tension adaptive variable-structure control system was designed for constant tension of electric cable plastic wrapping automatic production process. This system contains two inner loops for current and velocity control using PI regulators; its outer loop is for tension control using model reference adaptive controller. Simulation results indicate that the adaptive variable-structure controller...
The increasing penetration of generation power plants based on renewable energies in the electrical networks has boosted the number of systems connected to the grid. In this scenario the microgrid, providing advanced functionalities to improve the stability and operation of the network, have become very popular. In this paper a control strategy for the microgrid management is presented. The proposed...
Self oscillating control of LCC current-output resonant converter is presented based on varying the phase angle between the fundamental of the input voltage and current. Unlike other commonly employed control methodologies, the proposed technique is shown to provide a convenient, linear system input-output characteristic suitable for the design of regulators. The method is shown to have a similar...
In this manuscript, we propose an adaptive fuzzy logic controller for a DC-DC boost converter with parametric and load uncertainties. The control strategy aims to achieve accurate voltage tracking with unknown dynamics, highly parameter and load variations, and no current sensing. Therefore, robustness to uncertainties of large magnitudes is achieved without the inner current control loop, which reduces...
This paper presents a new technique of designing a direct digital controller for a single-phase pulse width modulation (PWM) converter system, based on closed-loop identification. It is difficult to analytically design a controller due to the double loop structure of the PWM converter control system. The design procedure consists of three steps. First, obtain a current controller for the inner loop...
A nonlinear mathematical model of three-phase voltage source PWM rectifier is established in the dq rotating frame. Aiming at the poor dynamic performance of conventional PI controlled three-phase PWM rectifier, a control system with double close-loops of voltage and current is designed based on the mathematical model of 3-phase PWM rectifier. A sliding-mode control algorithm on synchronous rotating...
This paper deals with shunt active power filtering for power quality improvement under unfavourable non-linear load and source conditions. A simple hybrid control strategy is used, based on a numerical integrator proportional (IP) DC bus controller combined with a phase-locked loop (P.L.L.) output to generate reference currents. A second analogue current controller is developed to insure- three phase...
In this paper an average current sharing mu-based robust controller for parallel multi-inverter systems is presented. There is one common output voltage controller to achieve low total harmonic distortion (THD) and good regulation. Each inverter module has also a robust current controller to track the averaged output current. This loop provides equal current distribution between inverters. The command...
Passivity-based control (PBC) is based on a procedure including energy/power shaping and series/parallel damping injection to control several nonlinear systems such as power converters. In this paper, PBC is used to design a controller for three phase/level/switch PWM (Vienna I) rectifier. Passivity-based controller is supposed to regulate the output voltage and the input three phase sinusoidal currents...
Summary form only given. This paper presents a new control strategy for islanded (autonomous) operation of an electronically-coupled distributed generation (DG) unit and its local load. The DG unit utilizes a voltage-sourced converter (VSC) as the coupling medium. In a grid-connected mode, based on the conventional dq-current control strategy, the VSC controls real- and reactive-power components of...
This paper presents a modified adaptive Kalman filter for sensorless current control of a three-phase inverter based distributed generation system. The delay introduced by measurements and the digital signal processor is compensated using a modified Kalman filter. The states of control variables can be estimated one sample in advance and the number of the measurement sensors can be reduced. For system...
A novel current assisted Hinfin controller for boost converter is presented in this paper. The proposed controller combines the Hinfin robust stabilization technique and classical loop-shaping. The current loop of the boost converter is closed with constant gain and then, the Hinfin controller is estimated and applied to the converter, closing the voltage loop. The derived controller has been compared...
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