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Voltage Regulation (voltage + regulation)
Selected AbstractsVOLTAGE REGULATION OF A BUCK BOOST CONVERTER,A HYBRID CONTROL APPROACHASIAN JOURNAL OF CONTROL, Issue 4 2007C. Sreekumar ABSTRACT In this paper, the output voltage regulation problem in a buck boost converter is defined as a hybrid control problem. For control design, the mutually interacting continuous and discrete dynamics are modeled as a hybrid automaton. Thus, the control problem is defined as a guard selection problem of the hybrid automaton. The system trajectory is switched between different modes based on the guards to achieve the required voltage regulation. The guards defined are fixed surfaces represented in terms of the state variables for a given operating condition. The logic-based switching in the state plane is stable in terms of the chaotic and bifurcation behavior. The effectiveness of the control scheme for buck and boost operation under line and load disturbances is demonstrated by simulation in the MATLAB-SIMULINK environment and the results are presented. [source] Local control of photovoltaic distributed generation for voltage regulation in LV distribution networks and simulation toolsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 6 2009Stefania Conti Abstract The increasing connection of distributed generation (DG) in distribution networks may affect the quality of power offered to customers. One of the most relevant issues is the possibility to have unacceptable voltage rise at the point of common coupling (PCC). This work focuses on the problem of voltage control in LV distribution networks in the presence of photovoltaic (PV) DG. The paper presents a local voltage control method based on PV generation curtailment as an alternative to ,on/off' operation, typically required by distribution operators to prevent overvoltage at the PCCs by means of overvoltage protections embedded in the PV unit. To show the effect of the proposed local voltage control, a simulation tool, developed in MATLAB®,Simulink® environment, is presented. Appropriate numerical models for network components and PV generators are provided in order to describe computer simulation implementation of the test system. The final results show that the control system is able to adjust the active power output of local generators to keep the voltage profile of the feeder, in which DG is installed, within the range allowed by Norm EN 50160. Copyright © 2008 John Wiley & Sons, Ltd. [source] Optimal Control of Voltage in Distribution Systems by Voltage Reference ManagementIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 5 2009Tomonobu Senjyu Student member Abstract Recently, renewable energy technologies such as wind turbine generators and photovoltaic (PV) systems have been introduced as distributed generations (DGs). Connections of a large amount of distributed generations may cause voltage deviation beyond the statutory range in distribution systems. A reactive power control of DGs can be a solution of this problem, and it also has a possibility to reduce distribution loss. In this paper, we propose a control methodology of voltage profile in a distribution system using reactive power control of inverters interfaced with DGs and tap changing transformers. In the proposed method, a one-day schedule of voltage references for the control devices are determined by an optimization technique based on predicted values of load demand and PV power generation. Reactive power control of interfaced inverters is implemented within the inverter capacity without reducing active power output. The proposed method accomplishes voltage regulation within the acceptable range and reduction of distribution loss. The effectiveness of the proposed method is confirmed by simulations. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] VOLTAGE REGULATION OF A BUCK BOOST CONVERTER,A HYBRID CONTROL APPROACHASIAN JOURNAL OF CONTROL, Issue 4 2007C. Sreekumar ABSTRACT In this paper, the output voltage regulation problem in a buck boost converter is defined as a hybrid control problem. For control design, the mutually interacting continuous and discrete dynamics are modeled as a hybrid automaton. Thus, the control problem is defined as a guard selection problem of the hybrid automaton. The system trajectory is switched between different modes based on the guards to achieve the required voltage regulation. The guards defined are fixed surfaces represented in terms of the state variables for a given operating condition. The logic-based switching in the state plane is stable in terms of the chaotic and bifurcation behavior. The effectiveness of the control scheme for buck and boost operation under line and load disturbances is demonstrated by simulation in the MATLAB-SIMULINK environment and the results are presented. [source] |