مدلسازی و ادغام تقاضای انعطاف پذیر در سیستم انرژی یکپارچه شده گرما و برق Modeling and Integration of Flexible Demand in Heat and Electricity Integrated Energy System

I. INTRODUCTION THE growing awareness of climate change and environmental issues entails the transition towards a low-carbon and sustainable energy system [1]. As an efficient measure to improve energy efficiency, the integrated energy systems (IES) have gained rapid development in recent years. The heat and power integrated energy system (HE-IES), based on combined heat and power (CHP), is one of the most important forms of IES [2]. Countries around the world have made great efforts to develop CHP. In Denmark, CHP covers about 40% of the demand for space heating [3]. In northern China, CHP based district heating (DH) has been installed in more than 300 cities, serving 40% of China’s population [4]. However, the inharmony between the high-penetration wind power and the wide use of CHP has become a challenge for operating the energy systems [5]. On the one hand, the fluctuation of wind power makes electricity price vary significantly during the operating day. Thus, the profit of CHP units can be dramatically reduced in periods of low electricity price resulting from large wind power production [6]. On the other hand, the electricity generation of CHP units is constrained by their heat production, which must target on customers’ heat demand. This leads to high wind power curtailment when the electricity production of CHP units covers most of the electricity demand during the off-peak hours[4]. Facing the challenges of integrating wind power with CHP units, a lot of researches have been conducted on increasing the flexibility of CHP based energy system. These works are mostly focused on decoupling the heat production from electricity generation by coupling CHP units with thermal storage or electric heating systems (EHS), such as heat pumps and electric boilers [7, 8]. However, these measures are more appropriate for relatively small CHP units used for district heating. For the centralized and high-capacity CHP units, it would be difficult to install the thermal stores of corresponding capacity. Moreover, the utilization of the heat storage capacity of the district heating network for increasing the flexibility has been proposed in [9].