Gajahwong River Continuous Flow Simulation by Using Soil Moisture Accounting (SMA) of HEC HMS

Gajahwong River is located in the southern part of Java Island, Indonesia, specifically on Daerah Istimewa Yogyakarta. Gajahwong River has an important role along the area where its discharge is used especially for irrigation water supply. Other factors stressing Gajahwong basin’s water supply purpose are population number rise and land cover change that influence river streamflow in the whole year. Hence, a continuous flow simulation was conducted to analyze Gajahwong River water availability to supply its requirement. The Soil Moisture Accounting (SMA) module of HEC-HMS was employed to simulate the continuous flow of Gajahwong River, particularly in Wonokromo Outlet. The continuous flow was simulated from the year 2012 until 2015 based on observed discharge data availability. Comparison between simulated and observed discharge was quantified by using R2, Nash-Sutcliffe efficiency and PBIAS statistic value. The statistic above parameter values yielded a value of 0.90, 0.58, and 2.02%, respectively for daily time series simulation.

Penanganan Pencilan pada Peramalan Data Deret Waktu Menggunakan Metode Pemulusan Holt dan Robust Holt

The time series data used is time series data following the LLTM (local linear trend model) model with four different error conditions. These conditions are Clean Data (CD), Symmetric Outliers (SO), Asymmetric Outliers (AO) and Fat-tailed data (FT). The time series data contains symmetric and asymmetric outliers that can affect forecasting. The forecasting method used for the trend data pattern is the Holt smoothing method. The forecasting of the data series when it is spinning using the Holt smoothing method is not good enough so that it requires a handler with the smoothing method of Holt robustness. The Holt robustness smoothing method that is carried out on time series simulation data is better used for the condition of scattered data compared to the Holt smoothing method. This is indicated by the value of evaluating the goodness of the method, namely the value of MAD (Mean Absolute Deviation) produced. The smaller MAD value for CD condition training data is the Holt smoothing method, while the data testing method for Holt and robust Holt smoothing is almost comparable. SO's condition for training data and data testing for smaller MAD values is the smoothing method of robust Holt. The condition of AO for training data and data testing for smaller MAD values is the smoothing method of robust Holt. In addition, the MAD value in FT conditions for training data and data testing found almost comparable results between the two methods.

Evaluating the Curtailment Risk of Non-Firm Utility-Scale Solar Photovoltaic Plants under a Novel Last-In First-Out Principle of Access Interconnection Agreement

With the increasing share of distributed energy resources on the electric grid, utility companies are facing significant decisions about infrastructure upgrades. An alternative to extensive and capital-intensive upgrades is to offer non-firm interconnection opportunities to distributed generators, via a coordinated operation of utility scale resources. This paper introduces a novel flexible interconnection option based on the last-in, first-out principles of access aimed at minimizing the unnecessary non-firm generation energy curtailment by balancing access rights and contribution to thermal overloads. Although we focus on solar photovoltaic (PV) plants in this work, the introduced flexible interconnection option applies to any distributed generation technology. The curtailment risk of individual non-firm PV units is evaluated across a range of PV penetration levels in a yearlong quasi-static time-series simulation on a real-world feeder. The results show the importance of the size of the curtailment zone in the curtailment risk distribution among flexible generation units as well as that of the “access right” defined by the order in which PV units connect to the grid. Case study results reveal that, with a proper selection of curtailment radius, utilities can reduce the total curtailment of flexible PV resources by up to more than 45%. Findings show that non-firm PV generators can effectively avoid all thermal limit-related upgrade costs.

An Alternative Proposal for Quantification of Technical Losses Using a Reduced Equivalent Circuit

Electrical grid technical losses affects the electricity tariff and the planning of new lines. Nonetheless, their assessment by means of time-series or real-time simulations is computationally burdensome for large grids. In order to achieve simplified equivalent circuits, reduction techniques have been developed. The only one that is applicable for unbalanced grids is the multiphase reduction, but it does not preserve the losses. This paper proposes an algorithm that allows indirect evaluation of total losses, thus extending the multiphase reduction technique. In the validation process, IEEE 34-bus and a Brazilian real feeder are evaluated. A daily time-series simulation, with hourly loadshapes, is performed in OpenDSS. Using this novel method, the losses errors obtained are lower than 2%. The proposed algorithm, therefore, may be applied to speed up the definition of electricity tariff and the planning process of unbalanced grids.

Highway wind power energy assessment of Al-Durra highway street in Baghdad, Iraq

In certain spots on the planet which have less attainable of utilizing enormous breeze power plants, the expressway wind vitality can be utilized to help little loads in the main grids. Interstates road lighting for instance of that heaps that is expending a great deal of vitality and cost every year. When the vitality that originates from vehicles development along the highway avenues can be taken in thought, this paper has examined the outcomes if moment vehicles wind speed during 24 hours per day. 24 hours, brief interim of vehicles wind speeds have been estimated by utilizing anemometer put in the road. A vertical pivot wind turbine (VAWT) has been proposed to be utilized in this task. All venture regulation has been simulated by utilizing Opendss program; it can support time series simulation. The outcomes demonstrated that the undertaking is possible to be utilized in Al-Durra Highway Street. The normal breeze speed of moving vehicles is 4.7 m/s which can deliver 67.3 watt by the proposed turbine. The got energy saw that it as contributed to be utilized by the maingrid during the day time. All the demonstrated bends of the outcomes speak to the Iraq grid support by diminishing the main demand and operational expenses too.