An approach for robustness analysis of non-dominated solutions to a multi-objective optimization model of an energy management system aggregator (EMSA) in face of uncertainty is presented. The EMSA is an intermediary ...
详细信息
ISBN:
(纸本)9781509042418
An approach for robustness analysis of non-dominated solutions to a multi-objective optimization model of an energy management system aggregator (EMSA) in face of uncertainty is presented. The EMSA is an intermediary entity between households and the System Operator (SO), capable of contributing to balance load and supply, and therefore coping with the intermittency of renewable energy sources (RES) and facilitating a load follows supply strategy in a Smart Grid environment. Household clusters provide load flexibility to satisfy system services requested by the SO, involving decreasing or increasing load in specific time slots. The EMSA multi-objective optimization model considers the maximization of profits and the minimization of the imbalance between the amounts of load flexibility provided by the end-user clusters to satisfy SO requests, taking into account revenues from the SO and payments to the clusters. A hybrid evolutionary approach combining Genetic Algorithms (GA) with Differential Evolution (DE) has been designed to deal with this model, and its behaviour subject to different scenarios of uncertainty is evaluated. The robustness analysis of non-dominated solutions produced by the hybrid evolutionary approach is based on the degree of robustness concept, taking into account the changes in the performance of the objective functions when small perturbations of the model nominal coefficients occur.
Tools used by clinicians to diagnose and treat insomnia typically include sleep diaries and questionnaires. Overnight polysomnography (PSG) recordings are used when the initial diagnosis is uncertain due to the presen...
详细信息
Tools used by clinicians to diagnose and treat insomnia typically include sleep diaries and questionnaires. Overnight polysomnography (PSG) recordings are used when the initial diagnosis is uncertain due to the presence of other sleep disorders or when the treatment, either behavioral or pharmacologic, is unsuccessful. However, the analysis and the scoring of PSG data are time-consuming. To simplify the diagnosis process, in this paper we have proposed an efficient insomnia detection algorithm based on a central single electroencephalographic (EEG) channel (C3) using only deep sleep. We also analyzed several spectral and statistical EEG features of good sleeper controls and subjects suffering from insomnia in different sleep stages to identify the features that offered the best discrimination between the two groups. Our proposed algorithm was evaluated using EEG recordings from 19 patients diagnosed with primary insomnia (11 females, 8 males) and 16 matched control subjects (11 females, 5 males). The sensitivity of our algorithm is 92%, the specificity is 89.9%, the Cohen's kappa is 0.81 and the agreement is 91%, indicating the effectiveness of our proposed method.
This paper investigates the performance of a three phase permanent magnet synchronous machine (PMSM) drive operating under a single fault, adopting a fault tolerant (FT) control, based on deadbeat - direct torque and ...
详细信息
ISBN:
(纸本)9781509007387
This paper investigates the performance of a three phase permanent magnet synchronous machine (PMSM) drive operating under a single fault, adopting a fault tolerant (FT) control, based on deadbeat - direct torque and flux control (DB-DTFC). DB-DTFC offers an independent regulation of the electromagnetic torque and the stator flux linkage by using a control law based on an inverse discrete time physical model. During fault conditions, the PMSM drive requires very limited hardware and software reconfigurations. The drive model equations result very similarly to those adopted for the healthy electric drive just by using a different matrix transformation set when the drive operates under a faulty condition. The proposed fault tolerant DB-DTFC ensures satisfactory faulty operations and drive stability, without increasing the computational efforts.
Variability of the solar energy resources requires highly effective maximum power point tracking (MPPT) to ensure maximum energy harvesting from the photovoltaic (PV) modules. To accomplish this, a MPPT controller typ...
详细信息
ISBN:
(纸本)9781509007387
Variability of the solar energy resources requires highly effective maximum power point tracking (MPPT) to ensure maximum energy harvesting from the photovoltaic (PV) modules. To accomplish this, a MPPT controller typically requires accurate knowledge of the voltage and current from the PV module, and must converge quickly with minimal hunting around the maximum power point (MPP). Conventional MPPT techniques use fixed step-size perturbation which need to be optimized for one of two objectives: reducing the convergence settling time, or reducing the steady state ripple. Also, the required sensors increase system cost and can cause reliability issues, particularly for the current sensors which can exhibit thermal drift and degrade over time. This paper presents a highly efficient, variable-step sensorless current MPPT controller using an observer-based model derived from the principles of model predictive control (MPC) to adaptively determine the perturbation step-size. The proposed variable step, sensorless current, model predictive control maximum power point tracking (VS-SC-MPC-MPPT) continuously adjusts the perturbation step size using the predicted dynamic model to enable fast convergence and small limit cycle, without the need of expensive measuring devices. The performance of the VS-SC-MPC-MPPT in this paper is compared to previously developed MPC-MPPT methods. The provided investigation aims to demonstrate higher system efficacy with lower cost. The feasibility of the proposed controller is verified though computer simulation and real time simulation using dSPACE DS1007.
Stochastic dynamic behavior of solar energy necessitates the use of robust controllers for photovoltaic (PV) power electronics interfaces to maximize the energy harvest by continuous operation at maximum power point (...
详细信息
ISBN:
(纸本)9781509007387
Stochastic dynamic behavior of solar energy necessitates the use of robust controllers for photovoltaic (PV) power electronics interfaces to maximize the energy harvest by continuous operation at maximum power point (MPP). This paper proposes a sensorless current model predictive control maximum power point tracking (SC-MPC-MPPT) algorithm. By predicting the future behavior of the power conversion stage, the proposed controller features fast and stable performance under dynamic ambient condition and negligible oscillation around MPP at steady state. Moreover, it does not require expensive sensing and communication equipment and networks to directly measure the changing solar insolation level. The power conversion stage includes an upstream boost dc/dc power conversion to a dc-link capacitor, and a downstream seven-level sub-Multilevel Inverter (sMI) from the dc-link capacitor to the grid. The sMI is using three power arms cascaded with an H-bridge inverter. This topology brings considerable benefits such as reduced number of power switches and their gate drivers when compared to the traditional multilevel inverters. Model Predictive Control (MPC) is employed for current regulation of the sMI, thus eliminating the need of cascaded classical control loops and modulator. The proposed SC-MPC-MPPT technique for a boost converter is implemented experimentally using the dSPACE DS1007 platform.
Including millimeter-wave (mm-wave) data in multi-wavelength studies of the variability of active galactic nuclei (AGN) can provide insights into AGN physics that are not easily accessible at other wavelengths. We dem...
详细信息
This paper was retracted by IOP Publishing on 12 December 2018. This paper was published due to a technical error and was not intended to be included in this journal. Retraction published: 8 February 2019
This paper was retracted by IOP Publishing on 12 December 2018. This paper was published due to a technical error and was not intended to be included in this journal. Retraction published: 8 February 2019
Based on the formulation of the problem to be discussed by the writer is to know: the influence of 0.4 mm spark gap variation, and standard spark plug type, to CO and HC, the influence of 0.5 mm spark plug gap variati...
Based on the formulation of the problem to be discussed by the writer is to know: the influence of 0.4 mm spark gap variation, and standard spark plug type, to CO and HC, the influence of 0.5 mm spark plug gap variation, and variation of platinum spark plug on CO and HC, influence of spark gap variation 0,6mm, and variation of iridium spark plug type to CO and HC emission Method used to obtain data needed to support the writer that is research method with experiment, literature study method or literature study The result of this research concludes that there is spark gap influence 0.4 mm, with variations of standard plug, platinum and iridium spark plugs against CO and HC emissions, where the lowest CO value is 0.27% and HC 98 ppm, 0.5 mm spark plug with lowest CO 0.15% and HC 46 ppm, 0.6 mm spark plug gap the lowest CO value of 0.19% and HC 24 ppm. The results of this research will be disseminated using the website
A fully homomorphic encryption system hides data from unauthorized parties, while still allowing them to perform computations on the encrypted data. Aside from the straightforward benefit of allowing users to delegate...
详细信息
A methodology for optimizing the geometry of a high power (HP) light emitting diode (LED) luminaire is presented in this paper. The arrangement of a HP-LED luminaire is evaluated, technically and economically, for out...
详细信息
ISBN:
(纸本)9781509023219
A methodology for optimizing the geometry of a high power (HP) light emitting diode (LED) luminaire is presented in this paper. The arrangement of a HP-LED luminaire is evaluated, technically and economically, for outdoor lighting. Parameters that affect both heat dissipation and lighting efficiency are considered. A finite element method (FEM) simulator is used to determine the thermal analysis and a stochastic ray tracing simulator is used to perform the lighting distribution. The thermal analysis of a HP-LED luminaire model is simulated and validated with 7.5% average error in LED temperature. An evaluation function is developed that considers the illuminance distribution on the target plane and the maximum temperature that reaches the LED chip. Optimized thermal and luminous results are presented and discussed.
暂无评论