Control
alireza khoshsoadat; mohamad Abedini; mohammad reza mirzaei
Abstract
Objective: Three-phase boost rectifier is a Voltage-Source Converter that converts three-phase AC input voltage to a higher DC voltage. In this paper, an artificial intelligent-based system, with learning and adapting ability, is designed for using in the two voltage-based control methods of rectifiers, ...
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Objective: Three-phase boost rectifier is a Voltage-Source Converter that converts three-phase AC input voltage to a higher DC voltage. In this paper, an artificial intelligent-based system, with learning and adapting ability, is designed for using in the two voltage-based control methods of rectifiers, with the names of Voltage Oriented Control (VOC) and Direct Power Control (DPC). For implementation of this intelligent controller a hybrid structure of the Fuzzy Logic (FL) and Neural Networks (NN) that named as Adaptive Network-based Fuzzy Inference System (ANFIS) is used. Among the common network training algorithms, the error back propagation algorithm is known as the most common solution by providing an efficient computational method, so in this article, the above method is used to design the controller. This neuro-fuzzy-based control model is applicable in both VOC and DPC methods and increases the correctness of the output current and DC voltage with low ripple, short settling time and also dynamic operation. The implementation of the proposed controller is simple and requires only 49 fuzzy rules. Compared to other controllers whose structure is neural network and fuzzy, it has fewer layers and its accuracy is higher.
Industrial Electronics
Hamid Radmanesh; Masood Saeidi
Abstract
The AC/DC converter is one of the popular power electronic converters in industrial applications such as in the railway, power supply systems and electric vehicle. In this paper, a three-phase controllable rectifier is considered and its linear model is extracted. Because of MPC controllers benefits, ...
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The AC/DC converter is one of the popular power electronic converters in industrial applications such as in the railway, power supply systems and electric vehicle. In this paper, a three-phase controllable rectifier is considered and its linear model is extracted. Because of MPC controllers benefits, the continuous control set model predictive controller (CCs-MPC) is designed for controlling this rectifier output DC voltage. By considering rectifier dynamic response, the suitable criteria to choice the model predictive controller parameters such as sampling time, prediction horizon and control horizon is proposed. In experimental implantation the computing burden of microcontroller is limit therefore the reaching to optimal and minimum complexity in algorithms implantation is vital problem. In other words by using these proposed criteria for selection of sample time, prediction and control horizon the tradeoff between computational burden, system performance and dynamic stability is made. When using designed MPC controller, the rectifier and grid performance such as total harmonic distribution (THD), power factor (PF) and output voltage ripple have acceptable value. This controller can eliminated the effect of heavy load change on rectifier performance which is very common problem in indusial system. Also, this controller stability guaranteed is checked by using the dual-mode method. The simulation results are validated by using MATLAB software and showing the designed controller performance.
Industrial Electronics
Mohammad Monfard; Mohammad Babaei; Saeed Sharifi
Abstract
This paper presents a wide range gain buck-boost type PFC rectifier based on the conventional buck-boost DC-DC converter. This novel rectifier is fed by a buck-type Z-source network at the DC side with the help of an inductor smoothing the AC side input current. The proposed PFC rectifier offers better ...
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This paper presents a wide range gain buck-boost type PFC rectifier based on the conventional buck-boost DC-DC converter. This novel rectifier is fed by a buck-type Z-source network at the DC side with the help of an inductor smoothing the AC side input current. The proposed PFC rectifier offers better input and output waveform qualities compared to the conventional buck-boost PFC rectifier. Maintaining near to unity power factor (PF) and low total harmonic distortion (THD) in a wide range of load variations and also the simple single-loop control are the main features of the proposed PFC rectifier. Furthermore, the switching frequency of the proposed rectifier can be chosen very higher than the competitors, since it successfully lets incredibly increase the duty cycle for a same voltage gain compared to the traditional solutions. This leads to reduced size of passive components and volume of the rectifier. A 250 W prototype circuit is designed and simulated considering most practical issues to evaluate the performance of the proposed PFC in both buck and boost modes. The results are compared with some of the well-known conventional PFC rectifiers that confirm the superior performance of the proposed topology.
Control
YousefReza Jafarian; Amin Karimi; Hassan Bevrani
Abstract
Compared to individual DC or AC microgrids, the Hybrid microgrids (HMGs) are more efficient and inexpensive due to eliminating of multiple DC-AC-DC conversions. In HMGs, where AC loads are supplied by DC link, load demand disturbance has direct negative effects on the DC link voltage. In this study, ...
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Compared to individual DC or AC microgrids, the Hybrid microgrids (HMGs) are more efficient and inexpensive due to eliminating of multiple DC-AC-DC conversions. In HMGs, where AC loads are supplied by DC link, load demand disturbance has direct negative effects on the DC link voltage. In this study, primary and secondary controllers are applied to realize suitable operation conditions and control the microgrid converters. Each converter has primary controller to compensate the demand power fluctuations. The secondary controller is also designed for extra demand varieties and sends the proper control signals for primary controllers. The expressed capability of primary controllers can be obtained by designing a simple and robust secondary controller. Hence, the effects of demand fluctuations are eliminated and the system is stabilized. The overall state space model of system is conducted for stability analysis. To demonstrate the proposed controller efficiency, a prototype HMG is modeled and simulated. The stability analysis reveals that the system is stable when the secondary controller tracks the error signal of DC link. Simulation results show that the proposed method could efficiently manage the AC side voltage under load fluctuations.
