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![Average hourly solar irradiance for the different seasons in Riyadh, 2017 [16].](profile/Siddig-Omer/publication/351848245/figure/fig3/AS:1027379061342209@1621957664375/Average-hourly-solar-irradiance-for-the-different-seasons-in-Riyadh-2017-16.png)
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![Figure 3. The 2017 monthly sum of electricity load in Riyadh [15].](profile/Siddig-Omer/publication/351848245/figure/fig2/AS:1027379061338114@1621957664354/The-2017-monthly-sum-of-electricity-load-in-Riyadh-15_Q320.jpg)
It is widely believed that the incorporation of renewable energy to the current power grid is the way forward in achieving sustainable power generation. Currently, with the reduction of PV prices, many countries have started connecting PV systems into their grid network, hence leading to a sharp increase of the penetration levels of renewable elect...
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Context 1
... hourly Global Horizontal Irradiance (GHI) data and the ambient temperature data were obtained from King Abdullah City for Atomic and Renewable Energy (K.A.CARE). The collected hourly Global Horizontal Irradiance (GHI) data and the ambient temperature data are shown in Figures 4 and 5, respectively. ...
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... the power ramps of the net load at different PV penetrations levels to the grid were compared to the power ramps of the original load. This was represented in a duration curve in terms of the ramping requirements per hour, which is shown in Figure 14. The duration curve in Figure 14 can be furtherly analyzed to showcase the ramping requirements for the grid's conventional generation system at various PV penetration levels to the grid. ...
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... was represented in a duration curve in terms of the ramping requirements per hour, which is shown in Figure 14. The duration curve in Figure 14 can be furtherly analyzed to showcase the ramping requirements for the grid's conventional generation system at various PV penetration levels to the grid. Table 3 showcases the ramping requirements for the grid's conventional generation system at various PV penetration levels to the grid in order to fully eliminate the curtailment of the PV energy due to the grid's ramping constraint. ...
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... 3 showcases the ramping requirements for the grid's conventional generation system at various PV penetration levels to the grid in order to fully eliminate the curtailment of the PV energy due to the grid's ramping constraint. According to Figure 14, the period from 1 to 1460 h coincided with the up ramping of the grid's conventional generation system due to the down ramping of the PV system. Generally, most of this period coincided with the afternoon period. ...
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... For instance, authors have tested the frequency stability at 5%, 10%, and 20% PV penetration concluded that the frequency stability of the grid is adversely affected at 20% PV penetration. Another study reported frequency deviations 59.37 to 60.54 Hz from nominal frequency (60 Hz) at 50% PV penetration level [29]. ...
Distributed photovoltaic (PV) systems are growing rapidly owing to considerable reduction in PV panel prices, renewable energy supporting policies, and technological advancements in inverter and controller designs. The variability and non-dispatchability of PV energy generation affect the reliability and stability of the electricity grid, leading to PV energy generation curtailment and its integration to power system. High penetration of PV systems in an electricity distribution grid causes various issues regarding voltage fluctuation, violation and unbalance. Installations of PV systems at transmission/sub-transmission level affect the power system frequency more than nodal voltages. Frequent changes in PV energy generation caused by passing clouds badly affect the grid frequency. As, penetration of PV systems in the electricity grids is accelerating, therefore, flexibility options to tackle the challenges of PV energy generation needs to be ensured/exercised. Amongst the available flexibility options, demand side management (DSM) seems to have considerable potential to cope with uncertain PV energy generation in an effective manner. This strategy refers to modulate the energy consumption patterns of flexible loads subject to time varying electricity pricing signals. DSM can provide regulatory services to the grid through the application of demand response (DR). DR enabled smart buildings have a great potential to provide ancillary services for accommodating PV energy generation in a power system. Grid service provision through smart buildings must give explicit consideration to occupants’ preferences. A paradigm that ensures the integrated operation of buildings and grid is named as building-to-grid (B2G) system. In this research work, B2G frameworks are further classified as: (1) buildingto-distribution-network (B2DN) for distribution system operation control (2) buildingto-transmission-network (B2TN) for transmission system operation control. Model predictive control (MPC) strategy embeds real-time disturbances i.e., PV energy generation and/or weather variations while performing optimization. This feature makes the MPC best fit to optimize the integrated operations of the buildings and a grid. Therefore, MPC based B2DN and B2TN are developed for distribution and transmission networks operations control. Existing B2DNs consider only best case PV generation scenario, ignoring the effects of PV generation variations. Therefore, to compensate for PV generation variations, the MPC has to be operated for real-time supply-demand balancing which requires a large potential of load flexibility and accurate prediction of PV energy generation. PV curtailment is believed to be an instant solution to rectify the variations in PV energy generation, however, resulting in wastage of PV energy generation resources. This research work focuses on an integrated solution of DR and PV energy generation curtailment in a B2DN paradigm. In this context, a two-stage B2DN optimization framework is developed. In first stage, PV energy generation is shaped through an on-site PV energy generation utilization parameter ‘g’ to solve intermittency issue. In second stage, MPC based optimization is performed that uses the synergy of energy storage system (ESS) and heating ventilation and air conditioning (HVAC) systems to extend the demand flexibility to provide voltage regulatory service. These two operational strategies, (1) PV self-consumption curtailment without DR (first stage operation only) and, (2) PV self-consumption curtailment with DR (two-stage operation) are compared in terms of B2DN’s performance parameters including building’s electricity cost, PVself consumption ratio (PV-SCR), grid’s load factor (LF), ramp rate control, and voltage regulation. Moreover, different PV energy generation scenarios are analyzed showing the effect of PV energy generation variations on B2DN performance parameters. Regarding transmission network operation control, existing B2TNs lack the integration of PV energy generation resources in electricity grids. In this context, this research work develops a decoupled B2TN integration mechanism based on frequency based real-time pricing (RTP) signals that facilitates the application of DR service and PV systems integration for the provision of frequency regulation. Separate MPC controllers are developed to control the dynamics of building and transmission networks. Building’s dynamics are modeled using grey box model (Resistor-capacitor network). Building’s MPC embeds real-time pricing (RTP) and real-time disturbances to the HVAC system such as outdoor temperature, solar irradiance and internal heat gains while performing optimization. The behaviour of power system frequency is described by swing equation at transmission system level. Grid’s MPC embeds load and PV energy generation variations in the optimization process. The interaction between buildings’ and grid’s MPCs is formulated through frequency based RTP. Three frequency based RTP signal generators namely;linear, hyperbolic tangent and inverse hyperbolic tangent are used to map frequency deviations to RTP signals. To enable DR service, a price responsive MPC for optimal scheduling of HVAC load is devised where reference temperature set point is dynamically adjusted with respect to RTP. The performance of the proposed B2TN is investigated in terms of frequency deviations suppression in clear and cloud covered sky conditions.
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