In many practical applications PLC engineers face the problem, that some essential hardware the PLC is supposed to operate, is not available during software development and commissioning, yet. Because of missing feedb...
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In many practical applications PLC engineers face the problem, that some essential hardware the PLC is supposed to operate, is not available during software development and commissioning, yet. Because of missing feedback signals from field, testing the control software can in such circumstances be very difficult, if ever possible. The purpose of the paper is to propose a certain method of programming, which enables the programmer to overcome the problem, at least partially. The key point of the method lies in replacing feedback signals generated by real hardware and sampled at PLC inputs, by signals generated inside the PLC by a special program block, performing software simulation.
Power flow calculations for systems with a large number of buses, e.g. grids with multiple voltage levels, or time series based calculations result in a high computational effort. A common power flow solver for the ef...
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ISBN:
(纸本)9781538645055
Power flow calculations for systems with a large number of buses, e.g. grids with multiple voltage levels, or time series based calculations result in a high computational effort. A common power flow solver for the efficient analysis of power systems is the Newton-Raphson algorithm. The main computational effort of this method results from the linearization of the nonlinear power flow problem and solving the resulting linear equation. This paper presents an algorithm for the fast linearization of the power flow problem by creating the Jacobian matrix directly in Compressed Row Storage (CRS) format. The increase in speed is achieved by reducing the number of iterations over the nonzero elements of the sparse Jacobian matrix. This allows to efficiently create the Jacobian matrix without having to approximate the problem. A comparison of the calculation time of three power grids shows that comparable open-source implementations need 3-14x the time to create the Jacobian matrix.
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