Interface Power Flow Research Articles

Transmission Interface Power Flow Adjustment: A Deep Reinforcement Learning Approach Based on Multi-Task Attribution Map

Transmission Interface Power Flow Adjustment: A Deep Reinforcement Learning Approach Based on Multi-Task Attribution Map

A Dispatching Method for Large-Scale Interruptible Load and Electric Vehicle Clusters to Alleviate Overload of Interface Power Flow

The study of dispatching methods for large-scale interruptible loads and electric vehicle clusters is of great significance as an optional method to alleviate the problem of overload in interface power flow. In this paper, the distribution model and transfer capacity of large-scale interruptible load and electric vehicle in two dimensions of time and space were firstly introduced. Then, a large-scale interruptible load and electric vehicle dispatching model considering transmission interface power flow balance was established. Finally, a case study was carried out with the city power grid as the research object. Studies show that by dispatching large-scale interruptible load and electric vehicle, the overload rate of interface power flow can be reduced by 12–17%, while the proportion of clean energy generation increased by 4.19%. Large-scale interruptible load and electric vehicles are quite different in terms of the role they play in grid regulation. The regulation cost of electric vehicles is higher than that of large-scale interruptible load, but it also has the advantages of promoting the consumption of clean energy and improving the overall operating economy. Which type of resource should be given priority is based on the actual state of the grid. In addition, the cost of electricity has a significant impact on the load response behavior of electric vehicles. It should be determined according to various factors, such as interface power flow control requirements, regulation costs, and power grid operation costs.

Calculating the Interface Flow Limits for the Expanded Use of High-Voltage Direct Current in Power Systems

Although loads are increasingly becoming concentrated in metropolitan areas, power generation has decreased in metropolitan areas and increased in nonmetropolitan areas; hence, power transmission must occur through interface lines. To achieve this, additional transmission lines must be secured because the existing interface lines have reached their large-scale power transmission limits. The Korea Electric Power Corporation has installed many high-voltage direct current lines, thereby impacting the determination of interface power flow limits. These serve as the basis for system operations. However, knowledge of operating high-voltage direct current lines as a simple transmission line in a single power system is lacking. The effects of high-voltage direct current and its related parameters for interface flow limit analysis remain unclear. Furthermore, whether high-voltage direct current should be included in the selection of the interface lines that serve as the basis for interface flow remains unclear. In addition, whether the high-voltage direct current line faults should be included in the contingency list for determining the interface flow limits has not been considered. Additionally, it has not been determined whether to operate the DC tap when performing the simulation This study addresses these issues and determines the conditions that are necessary for determining the interface flow limits when a high-voltage direct current transmission facility has been installed in a land power system. The results conclude how to reflect the above conditions reasonably when performing the interface flow limit analysis on a system that includes the HVDC lines.

KPI-based real-time situational awareness for power systems with high proportion of renewable energy sources

With the increasing complexity of power systems and the widespread penetration of renewable energy sources (RES), real-time situational awareness for power systems is of great significance for operation scheduling. With the impact of RES on power system operation considered, a situational awareness key performance index (KPI) system for power systems with high proportion of RES is proposed in this work, which consists of reserve capacity abundance, ramp resource abundance, center of inertia (COI) frequency deviation, interface power flow margin, synthesized voltage stability, and angle stability margin. Then, the KPIs are synthesized and visualized by decision tree method and radar chart method, respectively, for monitoring the operation states (i.e., normal, alert, and emergency states) of power systems with high proportion of RES. Numerical simulations are conducted in the revised New England 16-machine 68-bus power system and the actual CEPRI-RE power system in the northwest region of China with high proportion of RES. The results show that the proposed KPI-based situational awareness method is able to monitor the real-time state of power systems with high proportion of RES accurately, and can assist power dispatchers to make effective decisions.

육지계통 HVDC 확대와 DC Tap 설정에 따른 융통조류 여유량 산정에 관한 연구

The load continues to be concentrated in the metropolitan area, and the power generation is reduced in the metropolitan area, and the power generation in the non-metropolitan area is increased, so that power transmission is inevitably made through interface lines. In this environment, it is necessary to secure additional transmission lines because existing interface lines have reached the limit to transmit large-scale power. KEPCO has installed a number of HVDC alternatives, which will affect the determination of the limit of the interface power flow that is the basis for operating the system. In this paper, how to calculate the interface flow limit in this environment is described. According to DC tap setting in HVDC facilities, the interface power flow margin changes are monitored. It also discusses how to do with FV(Flow-Voltage) analysis in the future. The simulations were performed using the 8th planned Korean power systems data.

Determination of Interface Flow Stability Limits by Sensitivity Analysis of Transient Energy Margin

Due to the continued development and enhancement, the transient energy function method now provides accurate and reliable stability assessment. In this paper a procedure to determine stability limits in terms of interface power flow for a particular contingency is presented using analytical sensitivity of the energy margin. The proposed procedure is tested on a 17- generator equivalent of the network of the State of Iowa. Test results show that proposed procedure determines the stability limit accurately when the generation change is small or when the energy margin changes approximately linearly.