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This paper presents an approach for variable switching frequency digital control scheme under dynamic transients in order to improve the dynamic performance of the DC-DC switching power converter. The controller varies the switching frequency of the converter, higher or lower than the steady-state frequency, during the transient as a function of error signal depending on the amount and type of the...
An intelligent control stand-alone doubly-fed induction generator (DFIG) system using proportional-integral-derivative neural network (PIDNN) is proposed in this study. This system can be applied as a stand-alone power supply system or as the emergency power system when the electricity grid fails for all sub-synchronous, synchronous and super-synchronous conditions. The rotor side converter is controlled...
An efficient pre-filter based on interleaved DC-DC boost switching converters to mitigate high-frequency harmonics injection to power sources is proposed. The main feature of the pre-filter is to mitigate the ripple of power converters input-current, improving the efficiency of the whole power conversion chain. The pre-filter optimal operating conditions are calculated, and the circuit is modeled...
Voltage Source Converter (VSC) technology is very common in high-voltage direct current (HVDC) transmission systems. Compared to conventional VSC technology Modular Multilevel Converters (MMCs) offer advantages such as higher voltage levels, modular construction, longer maintenance intervals and improved reliability. For power transmission, stability, robustness of the control and especially the behavior...
The advent of grid-connected power electronics applications calls for a good understanding of the possible control methods. A common issue relates herein to the inherent nonzero steady-state error associated to stationary reference frame direct control of sinusoidal waveforms. This paper offers an alternative to the most-used proportional-integral-sinusoidal control solution (also called resonant...
The design of a Single Inductor Dual Output (SIDO) buck converter using two individual voltage mode control loops has been presented in this paper, and the limitation of using such control method has been indicated, then the control schemes for minimizing the cross regulation issue has been discussed. By using two separate control loops, the inductor energy is shared and regulated for both output...
PID controller has been frequently applied to various application areas because of mathematical definition and overall performance which is greatly depended on accuracy of the control parameters. Therefore, conventional and evolutionary algorithms have introduced to find these parameters as tuning methods. In present evolutionary algorithms have frequently used in PID tuning applications. However,...
The synthesis of a boost-converter-based loss-free resistor (LFR) operating in PWM is presented. The resulting LFR can be used as a preregulator for power factor correction in one-phase circuits. PSIM simulations are in good agreement with the theoretical predictions.
Input -series connected DC/DC converters based on one transformer is proposed for high voltage input and high power applications. Phase-shifted full-bridge (PS-FB) control strategy with common duty cycle control is adopted for each converter. Operation principles of the proposed converter are analyzed. Although primary currents vary for magnetic coupling and turns mismatch, combined peak current control...
Based on the input-output linearization method of differential geometry theory, the internal dynamics i.e. remaining dynamics of the nonlinear three-phase AC/DC voltage-source converter system, with output represented by (id, uc) i.e. direct voltage control and (id, iq) i.e. indirect voltage control respectively, are been studied. It is pointed out that the three-phase AC/DC voltage-source converter...
In this paper a fuzzy controller is designed for a recently developed voltage-boosting converter, named KY converter. The fuzzy controller neatly controls the switches of a 2nd-order KY converter via pulse-width-modulation (PWM) technology, which yields the voltage conversion ratio 2-plus-D where D represents the duty cycle. Experimental results show that the design simultaneously achieves faster...
This paper presents an alternative way for controlling the current of single-phase voltage source dc-ac inverters in a dq synchronous reference frame. In a dq reference frame, ac (time varying) quantities appear as dc (time invariant) quantities allowing the controller to be designed as for dc-dc converters presenting infinite control gain at the steady-state operating point to achieve zero steady...
This paper describes the complete design and implementation of a low-power sigma-delta DPWM (Sigma-Delta DPWM) controller for switching converter which can operate at a very high frequency. In the previous design approach, the effective resolution of Sigma-Delta DPWM, i.e. the effective number of bit (ENOB) is over-estimated by using the conventional signal-to-noise ratio (SNR) with a continuous-time...
This paper introduces a digital controller and a segmented power stage that dynamically change mode of operation to maximize power processing efficiency when highly dynamic loads are supplied. The controller operates as a mixed-signal peak current program mode voltage regulator, where a digital current reference is created and used for the efficiency optimization. The losses of the power stage are...
We consider a stabilization problem of DC-DC switching converters whose control input is given by pulse width modulation (PWM). In order to stabilize the DC-DC switching converter, this system is discretized. The discretized system is a nonlinear system for control input which is a duty ratio. Then, it is important to robustly stabilize an uncertain fixed point existed in the nonlinear system. In...
The predictive direct power control (P-DPC) strategy computes the application times of several voltage-vectors included in a predefined sequence. Until now only approximate solutions of the P-DPC have been presented. This contribution proposes two improvements to the P-DPC: the exact solution of the control problem and the fastest possible transient.
PID controller has the problems of inferior dynamic quality and bad anti-interference ability. However, variable structure controller has the disadvantages of chattering and big steady-state error. A new controller combines variable structure and PID control method for brushless DC motor (BLDCM) of magnetic suspended reaction flywheel (MSRW) is designed. It is based on analyzing of the MSRW system...
The highly need of flexibility and more robust controllers in areas such as motor controllers, renewable energy, and power electronics have opened the niche for applying and developing a new family of more active controllers such as: fuzzy, linear quadratic, passivity, pulse adjustment, etc. All these controllers are able to work in operations regions rather than at a single operation point and they...
Appling energy-shaping and port-controlled Hamilton (PCH) control principle, the model and control of the three-phase boost-type pulse-width modulated (PWM) ac/dc converters are presented in this paper. First of all, a PCH model of the three-phase PWM ac/dc converters is established in the d-q rotation frames. Then, according to the target of the controller design, the desired equilibrium point of...
An optimized control of PWM voltage source rectifiers (VSR) is presented. First, in a multi-input look-up table the different converter voltage-vectors are ordered with respect to their aptitude to increase (or decrease) the active power, depending on the angular position of the input voltage vector. A simple procedure allows the quick selection of the most suitable converter-voltage which ensures...
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