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Nowadays capacity of the photovoltaic systems in the grid is remarkable and provides a major part of energy in the grid. Therefore, an abruption of these systems from the grid can create a damage to the grid. Unlike in the past that PV systems disconnected from the grid when a voltage drop occurred, nowadays these systems should have Low Voltage Ride-Through (LVRT) capability. The PV system should...
The modular multilevel converter (MMC) is considered among the top choices for very high-power applications due to its superior features. To operate with good performance, effective control and modulation techniques are required to suppress the detrimental effects, including the circulating current and the capacitor voltage ripples. This paper proposes an efficient variable nearest level control-model...
In this paper, a current control is studied based on D-Σ digital control to improve the grid-connected performance for a three-level T-type inverter. The control principle is analyzed in accordance with the single-phase equivalent circuit of the three-level T-type inverter. The influence of the neutral-point voltage on both output current error and modulation signal is discussed, and the relationship...
This paper proposes a method for zero-crossing approximation of a band-limited sinusoidal signal embedded by a white Gaussian noise-like distortion. It consists of passive low-pass filter and dynamic-hysteresis comparator circuits. Simplicity and wide dynamic range are the main goal of the proposed approach. Theoretical calculations were formulated to select proper circuit components values. Simulation...
For the discussion about the neutral point potential (NPP) control of single phase three-level rectifiers, most of the methods solve the NPP problem by adjusting the zero-sequence voltage under symmetrical load conditions. However, when one phase voltage reaches to the maximum voltage, the other phase voltage goes to the minimal voltage. As a result, the NPP control ability is limited since there...
This paper focused on a fast mechanical switch applied in 2kV hybrid DC contactor. An integrated design of vacuum switch based on Permanent Magnetic Actuator (PMA) is proposed. The stainless steel bellows is removed to avoid vacuum failure caused by air leakage and eliminate restriction of bellows' fatigue life compared to conventional vacuum switch. Both monostable structure and compact springs'...
This paper introduces a control method for finite time stabilization of continuous-time controllable linear time invariant multiple-input multiple-output systems. The proposed approach uses higher order sliding mode control to reduce the system order to zero and thus providing the system states to reach the origin in finite time. Such control is called finite time order zeroing control, because it...
SF6 is a potent greenhouse gas and one of the promising alternatives is CO2. So this paper took CO2 rotating arc chamber as research object. The influence of the breaking angle and the magnetic field on the chamber was analyzed theoretically. Ansoft Maxwell software was used to simulate the magnetic field distribution in order to analyze the influence of the factors. Those factors are the number of...
In this paper, the design of a switched non-PDC controller, for a class of switched nonlinear systems subject to external disturbances is investigated for the purpose of satisfying robust H∞ output-feedback tracking performances. Based on multiple switched non quadratic-like Lyapunov functions, sufficient conditions for the existence of a switched non-PDC controller are formulated in terms of Linear...
In this paper, a new strategy combining the MDPSO (multimodal delayed particle swarm optimization) and continuous Bezier curve is developed for the global smooth path planning of mobile robots. Firstly, the preliminaries on Bezier curve and the MDPSO are briefly introduced. Secondly, the environment modeling is presented and the smooth path planning problem is mathematically formulated. Then, the...
This paper describes the application of a simplified indirect model predictive current control strategy for a direct Matrix Converter. The direct matrix converter has a large number of available switching states which implies that the implementation of predictive control high computational cost. In this paper, a predictive current control strategy is proposed in order to simplify the computational...
This paper presents a case study of different control approaches for a single phase Dual Active Bridge (DAB) based MVDC Shipboard power system (SPS). The Line Regulating Converters (LRCs) are based on DAB topology and the load side converters or Point of Load Converters (POLs) are based on buck topology. The tightly controlled POLs exhibit a constant power load (CPL) behaviour, which has a destabilising...
This paper presents a complete analysis, design and implementation of an enhanced space vector pulse width modulation (SVPWM) control for six-phase to three-phase grid connected matrix converter. The matrix converter (MC) is designed based on 18 bidirectional switches in order to interface a high performance fault tolerant multiphase permanent magnet synchronous generator (PMSG) to the main utility...
In the gene regulatory network, the gene regulation loop often occurs with multiple positive feedback, multiple negative feedback and coupled positive and negative feedback forms. In the above gene regulation loops, the auto-activation loop acts are ubiquitous regulatory motifs in complex bio-molecular networks. In this paper, we study the effect of the substrate concentration for gene expression...
The photovoltaic (PV) source simulators are widely used to test solar inverters, evaluate their control algorithms and study their grid integration issues in the laboratory settings. Many commercial programmable dc power supplies can be re-programed to be PV simulators. Due to the bulky output dc capacitors, the dynamic response and the bandwidth of these PV simulators are significantly limited, which,...
This paper proposes a digitally controlled bipolar converter for dc micro grids. The bipolar converter configuration is based on the combination of SEPIC and CUK converter with the modifications in both the converters. In the proposed bipolar converter, the equivalent series resistance (ESR) of the transfer floating capacitor is increased by inserting a series resistance in the both SEPIC and CUK...
The problem of control system design is discussed for a high frequency DC-DC converter which is based on the push-pull circuit with autotransformer. The proposed converter may be used as a battery discharge unit in power supply system of satellites. The mathematical model of the converter is described. The proportional-integral (PI) current controller and PI voltage controller are designed based on...
Wide band gap power semiconductor devices are now replacing the Si-MOSFET or IGBT. GaN-HEMT achieves the reduction in size and weight, thanks to its high frequency switching behavior. However, its high-speed switching characteristics and low threshold voltage may cause a false turn-on phenomenon, which is a fatal effect for the applications. It is urgent issue to tackle and avoid this problem by modifying...
Present paper demonstrates the effectiveness of the predictive deadbeat current control for Permanent Magnet (PM) Brushless (BL) DC motor drive in injection of square-wave phase current even at higher speed as compared to conventional PI controller employed for phase current control. Effectiveness has been demonstrated in terms of capability of minimizing current ripples and torque ripples ensuring...
This paper presents the application of a multiple switching pattern selective harmonic elimination on three level inverter. The aim of this work is to eliminate low rank harmonics (3rd, 5th, 7th and 9th) from an AC voltage waveform generated by DC to AC converter and also control the fundamental component, the modulation algorithm is based on the Newton-Raphson method which is one of the simplest...
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