A new Recursive Power Flow (RPF) algorithm for balanced/unbalanced radial distribution systems is proposed in this paper. Four generalized constant matrixes, that are calculated based on the graph theory, are used to obtain the power flow... more
A new Recursive Power Flow (RPF) algorithm for balanced/unbalanced radial distribution systems is proposed in this paper. Four generalized constant matrixes, that are calculated based on the graph theory, are used to obtain the power flow solution. These matrixes completely describe topology of a distribution system and models of its elements. In this method, each branch of a distribution system is considered as a bipolar. The method is able to consider detailed model of the elements. Solvability and convergence properties of the method have been mathematically presented. The method has been studied on the standard 16, 33 and 69-bus balanced distribution systems. In addition, this method is tested on 4 and 13-bus unbalanced standard distribution systems. Also, the method is tested on a 1337-bus real distribution system in Lorestan Electrical Power Distribution Company, Iran. The simulation results demonstrate the accuracy, computational efficiency and robustness of the proposed method.
The study and use of solid state transformers (SST) has grown exponentially, and new technologies are being developed every day. The application of a series resonant converter in a SST allows improvement of its efficiency, through soft... more
The study and use of solid state transformers (SST) has grown exponentially, and new technologies are being developed every day. The application of a series resonant converter in a SST allows improvement of its efficiency, through soft switching of the power switches. The present paper proposes a bidirectional topology capable of receiving an AC voltage in its input, and delivers the same AC voltage on its output through a series resonant converter and a push-pull AC-AC converter, with all switches operating with soft switching. The converter has three different switching elements and is capable of adjusting the output voltage level by changing the switching frequency. In this paper, the description of the converter's operation and simulation results are presented. A prototype is being built to be tested in laboratory.
This dissertation gives the investigation in the area of AC/AC power conversion and DC/DC with solid state transformer. The proposed single phase solid state transformer with bidirectional flow capability may find application in compact... more
This dissertation gives the investigation in the area of AC/AC power conversion and DC/DC with solid state transformer. The proposed single phase solid state transformer with bidirectional flow capability may find application in compact isolated PWM AC drives. This topology along with the proposed control has the following advantages. A)input power factor correction b) Common mode voltage suppression at the load end , c) high quality output voltage waveform (compared to the conventional space vector PWM) and d)minimizing output voltage losses, And lossless commutation for soft switching .
A New Model Solid State Transformer (NMSST) is used as a controllable bidirectional transmission device that can transfer power between asynchoronous networks and functionally similar to back-to-back-HVDC. This paper describes the basic... more
A New Model Solid State Transformer (NMSST) is used as a controllable bidirectional transmission device that can transfer power between asynchoronous networks and functionally similar to back-to-back-HVDC. This paper describes the basic concept of a New Model Solid State Transformer (NMSST). NMSST is a new technology used for many applications like Traction , Distribution Systems, Power Quality Improvement, Power factor correction etc. A digital simulation model of NMSST and its control system are developed using MATLAB. In this application field substantial weight and volume reduction can be achieved while providing additional functionality at the same time, also in this paper a survey of recent R&D efforts in this field are presented.
With the incremental power demand throughout the world, it becomes very much necessary to integrate Distributed Energy Resources (DERs) into the existing grid. Among the different DERs, the wind power has gained a great importance and... more
With the incremental power demand throughout the world, it becomes very much necessary to integrate Distributed Energy Resources (DERs) into the existing grid. Among the different DERs, the wind power has gained a great importance and market value. Because of being uncontrollable and unreliable resource, various issues related to power quality, stability and protection arise during the grid integration of wind power. Some other issues also occur because of the characteristics of different wind generators and interfacing devices like transformer and static reactive power compensators. Solid State Transformer (SST), a multistage converter based high frequency transformer has already proved its importance in different applications including DER integration for its inherent multi-functionalities. But still most of those functionalities have not been verified in all applications especially in wind power integration. In this thesis, one three phase SST is modeled and used for wind power interfacing. The possibility of power quality improvement is verified through simulation case study based on the data of Kanjikode 2MW SCIG based wind farm. The protection issues in wind based microgrid are identified. An adaptive sectional protection algorithm is proposed and verified through its simulation implementation in a wind power integrated microgrid test system.
