Hesamoddin Marzooghi

Aggregated demand response modelling for future grid scenarios

Abstract With the increased penetration of intermittent renewable energy sources (RESs) in future grids (FGs), balancing between supply and demand will become more dependent on demand response (DR) and energy storage. Thus, FG feasibility studies will need to consider DR for modelling net future demand. This paper proposes a generic demand model which represents the aggregated effect of DR in terms of a simplified market model of a FG. The model is based on a unit commitment problem aiming to minimise the system cost, and is intended specifically for modelling net demand by including the effect of DR in FG scenario studies. However, the model does not presume any particular market structure. As such, it is not suitable for modelling of existing electricity markets, but rather its aim is to capture the behaviour of future electricity markets provided a suitable market structure is adopted. The conventional demand model in the optimisation formulation is augmented by including the aggregated effect of numerous users equipped with rooftop photovoltaic (PV)-battery systems at higher voltage levels, without explicitly modelling the distribution level. In the model, the users are aiming to maximise self-consumption and are assumed to be price anticipators . As a case study, the effect of the demand model is studied on the load profile, balancing and loadability of the Australian National Electricity Market in 2020 with the increased penetration of RESs. The results are compared with the demand model in which users are assumed to be price takers .

Performance and Stability Assessment of Future Grid Scenarios for the Australian NEM

Shifting towards higher penetration of diverse renewable energy sources (RESs) in power systems is motivated mainly by reducing carbon emissions. In the long term of several decades, which we refer to in terms of the future grid (FG), balancing between supply and demand will become more challenging. Also, displacing conventional generators with RESs, especially inverter-based and intermittent RESs, could have significant effects on performance and stability of FGs. So far, FG feasibility studies have mostly considered simple balancing, but largely neglected network related issues such as line overload and stability. The main contribution of this paper is to present a simulation platform for performance and stability assessment of FG scenarios. As a case study, preliminary results on the balancing and stability of the Australian National Electricity Market in 2020 are illustrated with the increased penetration of wind and solar generation in the grid. Simulation results illustrate the importance of power system stability assessment for FG feasibility studies.

Impact study of prosumers on loadability and voltage stability of future grids

Feed-in-tariffs (FiTs) have been reduced due to combinations of economic and technical reasons. So, existing and new rooftop-photovoltaic (PV) owners are left with the option to either concede the low value arrangement or to use battery storage to maximise their self-consumption, and so minimise their electricity cost. This paper explores the effect of increasing penetration of residential battery systems on balancing and voltage stability of future grid (FG) scenarios. For this purpose, a generic demand model based on a Stackelberg game is employed to capture the interaction between an independent system operator (ISO) and prosumers. In this arrangement, the ISO attempts to minimise the total generation cost, whereas the prosumers aim to maximise their self-consumption by reducing their feed-in power. As a case study, we use the Australian National Electricity Market (NEM) to explore the impact of increased penetration of residential battery system on performance of the grid in 2020.

Aggregated effect of demand response on performance of future grid scenarios

The existing future grid (FG) feasibility studies have mostly considered simple balancing, but largely neglected network related issues and the effect of demand response (DR) for modelling nett future demand. This paper studies the effect of DR on performance of the Australian National Electricity Market in 2020 with the increased penetration of renewable energy sources (RESs). The demand model integrates the aggregated effect of DR in a simplified representation of the effect of market/dispatch processes aiming at minimising the overall cost of supplying electrical energy. The conventional demand model in the optimisation formulation is augmented by including the aggregated effect of numerous price anticipating users equipped with rooftop photovoltaic (PV)-storage systems. Simulation results show that increasing penetration of DR improves loadability and damping of the system with the increased penetration of RESs.

Generic Demand Model Considering the Impact of Prosumers for Future Grid Scenario Analysis

The increasing uptake of residential PV-battery systems is bound to significantly change demand patterns of future power systems and, consequently, their dynamic performance. In this paper, we propose a generic demand model that captures the aggregated effect of a large population of price-responsive users equipped with small-scale PV-battery systems, called prosumers, for market simulation in future grid scenario analysis. The model is formulated as a bi-level program in which the upper-level unit commitment problem minimizes the total generation cost, and the lower-level problem maximizes prosumers’ aggregate self-consumption. Unlike in the existing bi-level optimization frameworks that focus on the interaction between the wholesale market and an aggregator, the coupling is through the prosumers’ demand, not through the electricity price. That renders the proposed model market structure agnostic, making it suitable for future grid studies where the market structure is potentially unknown. As a case study, we perform steady-state voltage stability analysis of a simplified model of the Australian National Electricity Market with a significant penetration of renewable generation. The simulation results show that a high prosumer penetration changes the demand profile in ways that significantly improve the system loadability, which confirms the suitability of the proposed model for future grid studies.

Aggregated effect of price-taking users equipped with emerging demand-side technologies on performance of future grids

The increased penetration of intermittent renewable energy sources (RESs) requires flexible resources such as demand response (DR) and energy storage to achieve balance between demand and supply in future grids (FGs). Hence, it is necessary to consider the impact of emerging demand-side technologies for modelling net demand in FG Scenarios. This paper studies the aggregated effect of PRICE-TAKING USERS equipped with such technologies on the performance of FGs. For such a study, a GENERIC demand model is developed, which captures the essential behaviour of those users at higher voltage levels. The demand model, inspired by the smart home concept, is formulated as an optimisation problem aiming to minimise the electricity cost. To showcase the performance of the model, we study the effect of price-taking users equipped with rooftop photovoltaic (PV)-battery systems on the load profile, balancing and loadability of the Australian National Electricity Market with an increased penetration of RESs.