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The DC current rejection of a single phase half-bridge grid-connected inverter with a line-frequency isolation transformer is researched in this paper. The impact of the magnetic dc bias of the transformer is given out from the mathematic model of the transformer in current-mode control. For the half-bridge current-mode inverter, the dc current rejection method is presented based on the relationship...
By analyzing luminous process and volt-ampere characteristics of gas discharge lamp, a piecewise linear regress mathematical model is proposed. An illuminated loop-locked intelligent adjust light controller is designed by using power switching devices and SPWM variable voltage variable frequency controlling means. The above design can modify pulse and control carrier-to-noise ratio. Within a certain...
This article, firstly, introduced the operating principle of variable speed constant frequency (VSCF) wind power generation based on a structure of dual PWM converter. Then the mathematical model of network-side and rotor-side converter was set up. Decoupling control and vector control technique were presented based on grid voltage orientation and stator flux orientation to simplify the control strategy...
This paper describes a fuzzy control system and simulation for ultrasonic motors. Although ultrasonic motor has much merit, such as small size, light weight, high precision, fast control dynamics and large driving force when low speed, etc. However, the nonlinear dynamic characteristic and the accurate mathematical model is difficult to obtain. So the traditional control method is almost no effect...
This article presents a new approach to fast mixed-mode simulation of phase-locked loops (PLLs) in time domain using Spice-like simulators and behavioral Verilog-A baseband (BB) models of voltage-controlled oscillators (VCO) and frequency dividers (FD). Other PLL blocks like phase-frequency detectors (PFD), charge pumps (CP), and loop filters (LP) can be transistor level and/or behavioral models....
The advance in energy storage technologies allows to improve significantly the performances of electrified light transportation systems. This is aligned with the massive requirement of competitiveness compared to other transportation technologies in terms of sustainable energy and high reduction of environmental impact. The installation of stationary storage devices, as widely recognized, allows the...
This paper proposes a combined Secondary and Tertiary Voltage Regulation (SVR+TVR) methodology based on real-time optimal power flows (OPFs) to periodically update the generators' voltage regulator set points. Minimum active power losses (MAPL) and maximum loadability (ML) OPF approaches are used for the proposed SVR+TVR control. The presented technique is compared against a “classical” SVR control,...
This paper presents three models for dynamic analysis of inverter-based distributed generators equipped with voltage positive-feedback anti-islanding protection. The models analyzed are: the switched model, where the switches are represented in details, the average model, where the switches and signal generators are replaced by controlled voltage sources, and the small-signal model, where the average...
In this paper, we present a variable speed wind induction generator associated to a flywheel energy storage system. Direct torque control strategy for an induction generator used in the flywheel energy storage system, is applied. Both rotor flux and DC bus voltage are regulated by the applied of the standard switching table for an operation in the 4 quadrants. This system is used for improving the...
This paper deals with an application of the power balance theory in a voltage and frequency controller (VFC) of an autonomous wind power generation 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. Three-leg voltage source converter (VSC)...
This paper presents the implementations of a new control algorithm for a three-phase shunt active power filter to regulate load terminal voltage, eliminate harmonics, and improve the power factor in systems with an uncontrolled rectifier and an AC controller as the non-linear loads. Different methods are used to control the active power filters. The reference current to be detected from the load current...
This paper presents artificial neural network (ANN) based controller model to simulate the automatic voltage regulator (AVR) response for the transient stability analysis. Two different models are simulated considering single machine connected to an infinite bus (SMIB) to check the response of NN behaviour with conventional controller. Based on simulation results, it is found that NN controller gives...
In this paper the operation of 50 kW PEM fuel cell system as distributed generation is studied. The objective of this work is to develop the modeling and control framework for such distributed generation to enable their operation in a distribution system. A new control strategy for the operation of the fuel cell system in both grid connected and islanded modes is proposed to enable better management...
Switched mode power supplies (SMPS) have become an indispensable part of modem electronic systems. In this paper, a generalized MATLAB/SIMULINK modeling techniques is presented. The proposed techniques have been successfully integrated into SMPS design course at Lunghua University, Taiwan. The main objective of the course is to teach final year undergraduate students and first year Master's students...
This paper develops the control system of a piezoelectric micropositioner with an optimal PID control approach. In the control system development, the piezoelectric micropositioner is actuated by a voltage amplifier which is implemented by a linear operational amplifier with a compensator cascaded and the optimal PID control approach for trajectory tracking is developed from an approximated second-order...
The control strategy for three-phase-high-power-factor PWM rectifier is studied, and the methodology of building the small signal model of the main power circuit is proposed in this paper. High frequency model for the rectifier mentioned and the input-to-output transfer function for the system are deduced with analysis. Design principle and method of the voltage regulator are given based on the model...
A novel hybrid control based on digital variable-band hysteresis discrete pulse modulation (DPM) control and repetitive control is proposed for a 400 Hz inverter. The good dynamic response of the DPM inverter is obtained by the digital hysteresis control, and the steady state control performance is improved significantly by the repetitive control. By utilizing the variable hysteresis band, the stability...
To develop and apply renewable energy, one of the key technologies is that a kind of inverter outputting high quality sinusoid signals to power network is required. This paper proposed a three-phase buck-boost inverter, which can generate a three-phase ac output voltage larger than the dc input one. Its basic configuration is introduced, and the system stability of open-loop is analyzed by constructing...
This paper presents a new solution, which can completely remove the DC offset and make the dynamic error of flux observation smaller when using the modified voltage model compensated by rotor flux oriented current model. The modified voltage model with error compensation not only completely eliminates the integration drift, but also realizes errorless flux estimation in steady state and dynamic state...
This paper presents a novel DC link voltage feedforward control to improve the electric drive system tolerance capability to the dc link voltage sag. A uniform mathematic model, comprising the battery packs, voltage source inverter (VSI), permanent magnet synchronous motor (PMSM) is built up in the d-q rotating coordinates rather in three-phase stationary coordinates. In order to study the influence...
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