Power Distribution Management System revisited: Single-thread vs. Multithread Performance

Power Distribution Management System (PDMS) uses very sophisticated algorithms to deliver reliable and efficient functioning of power distribution networks (PDN). PDNs are represented using very large sparse matrices, whose processing is computationally very demanding. Dividing large PDNs into smaller sub-networks results in smaller sparse matrices, and further processing each sub-network in parallel significantly improves the performance of PDMS. Using multithreading to further process each sub-network however degrades PDMS performance. Single-thread processing of sub-network sparse matrices gives much better performance results, mainly due to the structure of these matrices (indefinite and very sparse) and synchronization overhead involved in multi-thread operations. In this paper an overview of PDMS system is presented, and its performance given single-thread and multiple threads is compared. The results have shown that for some applications, single-threaded implementation in multi-process parallel environment gives better performance than multithreaded implementation

Power System Probabilistic and Security Analysis on Commodity High Performance Computing Systems

<p>Large scale integration of stochastic energy resources in power systems requires probabilistic analysis approaches for comprehensive system analysis. The large-varying grid condition on the aging and stressed power system infrastructures also requires merging of offline security analyses into online operation. Meanwhile in computing, the recent rapid hardware performance growth comes from the more and more complicated architecture. Fully utilizing the computing power for specific applications becomes very difficult. Given the challenges and opportunities in both the power system and the computing fields, this paper presents the unique commodity high performance computing system solutions to the following fundamental tools for power system probabilistic and security analysis: 1) a high performance Monte Carlo simulation (MCS) based distribution probabilistic load flow solver for real-time distribution feeder probabilistic solutions. 2) A high performance MCS based transmission probabilistic load flow solver for transmission grid probabilistic analysis. 3) A SIMD accelerated AC contingency calculation solver based on Woodbury matrix identity on multi-core CPUs. By aggressive algorithm level and computer architecture level performance optimizations including optimized data structures, optimization for superscalar out-of-order execution, SIMDization, and multi-core scheduling, our software fully utilizes the modern commodity computing systems, makes the critical and computational intensive power system probabilistic and security analysis problems solvable in real-time on commodity computing systems.</p

A mixed-signal computer architecture and its application to power system problems

Radical changes are taking place in the landscape of modern power systems. This massive shift in the way the system is designed and operated has been termed the advent of the ``smart grid''. One of its implications is a strong market pull for faster power system analysis computing. This work is concerned in particular with transient simulation, which is one of the most demanding power system analyses. This refers to the imitation of the operation of the real-world system over time, for time scales that cover the majority of slow electromechanical transient phenomena. The general mathematical formulation of the simulation problem includes a set of non-linear differential algebraic equations (DAEs). In the algebraic part of this set, heavy linear algebra computations are included, which are related to the admittance matrix of the topology. These computations are a critical factor to the overall performance of a transient simulator. This work proposes the use of analog electronic computing as a means of exceeding the performance barriers of conventional digital computers for the linear algebra operations. Analog computing is integrated in the frame of a power system transient simulator yielding significant computational performance benefits to the latter. Two hybrid, analog and digital computers are presented. The first prototype has been implemented using reconfigurable hardware. In its core, analog computing is used for linear algebra operations, while pipelined digital resources on a field programmable gate array (FPGA) handle all remaining computations. The properties of the analog hardware are thoroughly examined, with special attention to accuracy and timing. The application of the platform to the transient analysis of power system dynamics showed a speedup of two orders of magnitude against conventional software solutions. The second prototype is proposed as a future conceptual architecture that would overcome the limitations of the already implemented hardware, while retaining its virtues. The design space of this future architecture has been thoroughly explored, with the help of a software emulator. For one possible suggested implementation, speedups of four orders of magnitude against software solvers have been observed for the linear algebra operations