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This paper presents a methodology for the design of over-frequency containment schemes in low inertia, high renewable systems. This methodology is demonstrated through the comprehensive redesign of the containment scheme for significant over-frequency events (e.g., the loss of an exporting HVDC interconnector) in the Ireland and Northern Ireland power system (All-Island System). The new scheme allows an existing synchronous generator runback system integrity protection scheme to be replaced with fixed wind tripping and dynamic response from wind. This exploits the capabilities of renewable generation to create effective protection and control resources. The methodology provides the steps required to determine the key parameters of the scheme (e.g., maximum allowable frequency, required volume of tripping, lowest trip frequency). A key consideration of the methodology is the volume of dynamic response from wind that can be deployed before frequency limits are violated (e.g., inertia and wind penetration). Dynamic simulations are performed in DSE Tools for the All-Island system considering a 2020 operational scenario. These simulations support the application of the methodology and demonstrate the effectiveness of the scheme designed for the All-Island system. [ABSTRACT FROM AUTHOR]

Accurate and rapid load forecasting for industrial customers has been playing a crucial role in modern power systems. Due to the variability of industrial customers’ activities, individual industrial loads are usually too volatile to forecast accurately. In this paper, a short-term load forecasting model for industrial customers based on the Temporal Convolutional Network (TCN) and Light Gradient Boosting Machine (LightGBM) is proposed. Firstly, a fixed-length sliding time window method is adopted to reconstruct the electrical features. Next, the TCN is utilized to extract the hidden information and long-term temporal relationships in the input features including electrical features, a meteorological feature and date features. Further, a state-of-the-art LightGBM capable of forecasting industrial customers’ loads is adopted. The effectiveness of the proposed model is demonstrated by using datasets from different industries in China, Australia and Ireland. Multiple experiments and comparisons with existing models show that the proposed model provides accurate load forecasting results. [ABSTRACT FROM AUTHOR]

In view of the increasing levels of renewable generation across the world, the operational dynamics of power systems are changing. One of the dimensions of this transformational change is the nature of fault ride through behavior of renewable technologies such as wind and the associated differences compared to conventional generation. This paper investigates the impacts of fault ride through behavior of wind farms on the system stability in detail, using full dynamic model of a low inertia island power system. Recorded PMU measurements are used to establish the variations in wind farm behavior during and after a fault. A detailed sensitivity analysis on the active and reactive power injection behavior of wind farms is carried out to establish the component of fault ride through behavior that is most critical to system stability, using the full model of the Ireland and Northern Ireland Power system (All island power system). Detailed investigation of the mechanics of a fault in a low inertia, wind generation dominated system is carried out to reveal potential technical scarcities. Finally, mitigations for identified scarcities arising from non-ideal fault ride through behavior of wind farms are presented in terms of Transmission System Operator led novel system services. [ABSTRACT FROM AUTHOR]

This paper describes a power system inertia estimation method that utilizes power perturbations caused by the flow switch on an HVDC interconnector. The analysis is performed using real power system measurements from Ireland's all-island power system. The method employs an energy based estimation technique which permits a non-step power change to be used for inertia calculation and encapsulates the challenges associated with the use of real data. While it is shown that synchronous generators account for most of the power system inertia, other contributors are also investigated, namely power station auxiliary load, distributed generation and power system demand. Time-of-day and wind related effects on Ireland's power system inertia are explored. Recommendations are made for the practical implementation of the method. [ABSTRACT FROM AUTHOR]

The capacity value of wind power indicates the extent to which wind power contributes to the generation system adequacy of a power system. The related data requirements may be subject to difficulties due to the temporal variability and spatial distribution of wind power in connection with the limited databases currently available. This paper presents a methodology to identify the minimal amount of data required for reliable studies. Based on wind power data of 74 stations in Ireland, covering up to ten years, the effects of different numbers of stations and different time periods of data on the capacity value are analyzed. The calculations are performed by means of a fast calculation code. The results show that at least four to five years of data in an hourly resolution are necessary for reliable studies and that 40 to 50 evenly distributed stations give an acceptable representation of the total wind power generation in Ireland. [ABSTRACT FROM AUTHOR]

Tidal stream generation is a form of renewable energy that is predicable but variable in nature. The paper initially identifies the tidal resource around Ireland, utilizing the most appropriate and developed tidal energy technology, thus providing a potential magnitude and output profile. Methods of deployment and control, including the down rating of the generator relative to turbine size and operational output reduction, are suggested to reduce capital cost, increase the capacity factor and reduce the impact on the grid system. The combination of the potential resource and the application of control methods provide the basis to study the effect on the grid system in terms of ramp rate and the demand profile. The same inputs also provide the ability to analyze generator characteristics such as the capacity credit. [ABSTRACT FROM AUTHOR]

Synchronous island power systems, such as the combined Ireland and Northern Ireland power system, are facing increasing penetrations of renewable generation. As part of a wider suite of studies, performed in conjunction with the transmission system operators (TSOs) of the All-Island system (AIS), the frequency stability challenges at high and ultra-high wind penetrations were examined. The impact of both largest infeed loss and network fault induced wind turbine active power dips was examined: the latter contingency potentially representing a fundamental change in frequency stability risk. A system non-synchronous penetration (SNSP) ratio was defined to help identify system operational limits. A wide range of system conditions were studied, with results showing that measures such as altering ROCOF protection and enabling emulated inertia measures were most effective in reducing the frequency stability risk of a future Ireland system. [ABSTRACT FROM AUTHOR]

Although wave power installations are currently limited in number, the capacity value of wave power is of interest in power system planning. The capacity value of wind power has been studied in previous work, but the value for wave power is not known. Continuous time series characterizing the wave energy resource at multiple sites are generated from raw wave data. These time series are analyzed with a forced outage rate imposed for individual devices, as may be encountered by real wave energy farms. The capacity value of wave power at various sites is evaluated with reference to 500 MW of installed capacity. Portfolios are created, allocating wave power capacity to individual sites, with the impact of geographical aggregation being examined. The inter-annual variation for each portfolio is then determined in order to examine the robustness of the results. Comparison is also made between sites off the west coasts of Ireland and Portugal. The implications for the power system resulting from an increase in generation adequacy are discussed. [ABSTRACT FROM PUBLISHER]

A stochastic mixed integer linear optimization scheduling model minimizing system operation costs and treating load and wind power production as stochastic inputs is presented. The schedules are updated in a rolling manner as more up-to-date information becomes available. This is a fundamental change relative to day-ahead unit commitment approaches. The need for reserves dependent on forecast horizon and share of wind power has been estimated with a statistical model combining load and wind power forecast errors with scenarios of forced outages. The model is used to study operational impacts of future high wind penetrations for the island of Ireland. Results show that at least 6000 MW of wind (34% of energy demand) can be integrated into the island of Ireland without significant curtailment and reliability problems. [ABSTRACT FROM AUTHOR]

A model suitable for studying the short-term dynamic response of a combined-cycle gas turbine (CCGT) to a system frequency deviation is developed. The model is used in conjunction with a larger system model to study the impact of increasing levels of CCGT generation on frequency control of a small island system. The study considers single contingencies and does not consider severe cascading-type events. A consequence of the results is that as the number and proportion of base-loaded CCGTs increases, frequency control may become more challenging. The results indicate that with additional CCGTs on the system large frequency excursions will be more likely, and the transmission system operators on the island of Ireland should review their frequency control strategies in the future to avoid the shedding of customers. [ABSTRACT FROM AUTHOR]