Open Power System Numerical Simulation System Based On Cloud Computing

The numerical simulation plays an irreplaceable role in the power system planning, operation and security. Having complete models, acceptable computation accuracy and efficiency is the basic requirement of power system numerical simulation software. With the scale of the power system increasing, analysis demands of users have been becoming more and more diverse. To enable users to analyse and solve various problems quickly and flexibly, developing power system simulation software with excellent openness is of great significance.Based on studying various power system numerical simulation softwares and analysing the problem of large amounts of idle computer resources, this paper presented an open power system numerical simulation system scheme which is based on the cloud concept. And the main contributions are stated below.Firstly, the concept and role of the openness of power system numerical simulation program were discussed, emphasizing the significance of API (Application Program Interface)-based secondary development for the simulation software. An open power system simulation software system based on Client/Server (C/S) mode has been developed. The communication between two sides was realized through TCP/IP and with an identical standardized database (a normalized function table) established on both sides, the open application program interface was realized through table lookup, so the interaction between the client side and server side was achieved. The client-side secondary development is not limited to one programming language. Interface software packages have been developed in different programming languages including C++, Matlab and Python. For the calculation engine on the server side, open power system load flow calculation module and open power system electromechanical transient simulation module have been developed. Through experiments, it is verified that this kind of secondary development proposal enables users to utilize server-side powerful resource and develop various advanced analysis program, which is most convenient and efficient. Secondly, the characteristics and applications of cloud computing were introduced. Combined with the concept of cloud resource sharing, the software system based on the C/S mode was extended to the cloud service mode. The power system numerical simulation system scheme based on the cloud concept was designed and the method of collaborative work between the client side and the cloud side was determined as well. In this scheme, cloud-side resource pool can be established quickly and easily. The calculation engine and service interface software are installed on a wide range of computers and the service interface software is connected to the cloud-side dispatching centre so as to establish the resource pool. Multiple interface softwares are installed on the high performance computers so that they can provide services to multiple clients at the same time.Finally, the computing ability index and available computing ability index were proposed, which were applied to the cloud service dispatching strategy of the power system numerical simulation system. The cloud-side dispatching centre is responsible for listening to user’s service application and monitoring the CPU utilization and memory utilization of various resources and facilities so as to calculate their current available computing ability indexes. When receiving user’s service application, the dispatching centre will assign the service interface of the computer whose current available computing abilitiy value is the biggest to the user, which ensures that the computer load balance. Through experiment, it is verified that this system is able to utilize all kinds of idle computing resources to supply service to users without affecting the normal work of resource supplier.