Flexibility Evaluation Method of Power Systems with High Proportion Renewable Energy Based on Typical Operation Scenarios

Abstract

The development of renewable energy represented by wind, photovoltaic and hydropower has increased the uncertainty of power systems. In order to ensure the flexible operation of power systems with a high proportion of renewable energy, it is necessary to establish a multi-scenario power system flexibility evaluation method. First, this study uses a modified k-means algorithm to cluster operating scenarios of renewable energy and load to obtain several typical scenarios. Then, flexibility evaluation indices are proposed from three perspectives, including supply and demand balance of the zone, power flow distribution of the zone and transmission capacity between zones. Next, to calculate the flexibility evaluation indices of each scenario—and according to the occurrence probability of each scenario—we multiplied the indices of each scenario by the scenario occurrence probability to obtain comprehensive evaluation indices of all scenarios. Based on the actual historical output data of renewable energy and load of a southern power system in China, a flexibility evaluation was performed on the modified IEEE 14 system and modified IEEE 39 system. The results show that the proposed clustering method and flexibility indices can effectively reflect the flexibility status of the power system.

Adaptive Grid Partitioning Considering Power Supply and Load Distribution

“…The flexibility evaluation index in the region includes the poor flexibility index on supply and demand in the region. The inter-regional flexibility assessment index includes the poor flexibility index of inter-regional transmission capacity [26].…”

“…Regional upward and downward flexibility supply is provided by thermal power units and energy storage devices, and the calculation process is as follows: Based on the above mentioned upward and downward flexibility demand and supply, the index of upward and downward flexibility can be obtained[26]:…”

Emerging Technologies in Power Systems

“…RES in the power system causes uncertainty problems due to their intermittent characteristic [10][11][12]. The paper in [10], with the title of "Transmission grid expansion planning of a high proportion renewable energy power system based on flexibility and economy", presents a multi-objective transmission system planning model considering economy and flexibility.…”

“…The proposed approach derives a solution by formu-lating separate objective functions for fuel cost, power losses, as well as combined economic and environmental costs (CEEC) of power system. The paper in [12], entitled "Flexibility Evaluation Method of Power Systems with High Proportion Renewable Energy Based on Typical Operation Scenarios", presents a power system flexibility evaluation method based on several general scenarios by clustering the operation scenarios of renewable energy and loads using the modified k-means algorithm. The flexibility evaluation method is expressed as an index by considering the demand balance, power flow, and transmission capacity.…”

Low Sensitivity Predictive Control for Doubly-Fed Induction Generators Based Wind Turbine Applications

“…Accordingly, to slow down the increase of the earth temperature, all the governments around the world started to increase the share of renewable energy systems in the power generation. Two types of renewable energy systems are extensively installed worldwide: Wind and photovoltaic energy systems [1][2][3][4]. The constant-speed wind turbines with squirrel-cage induction generators are the first type that appeared in the wind turbines market.…”