Papers by Keyword: Hybrid Simulation

Abstract: The present paper suggests an on-line hybrid test environment for evaluating the seismic performance of steel bracing connections. The test method combines substructuring techniques and finite element analysis. The behavior of the brace member is simulated by the finite element analysis program ABAQUS, while the bracing end connections are physically tested. Two actuators are used to simulate the physical continuity between the analytical and experimental substructures by controlling axial load and out-of-plane rotation. A MATLAB user subroutine is created as the interface between the main control program and ABAQUS to impose the target rotation and axial force to the connection quasi-statically. A gusset plate connection designed to behave as a pin connection is tested and its efficiency to accommodate inelastic rotations up to a 4.0% story drift is evaluated. The test method is reasonable and smooth operation is achieved. The test system ensures pragmatic loading and boundary conditions to the brace connections, which are tested in full interaction with the brace member until failure. The maximum strength and rotation capacity of the connection can be clarified under actual cyclic inelastic rotations and varying axial loads derived from the inelastic behavior of the brace member.

Abstract: Hybrid simulation, or hybrid testing, is understood here as a numerical technique for investigating dynamic properties of mechanical systems with components that are difficult to model numerically. This technique can be also referred to as hardware-in-the-loop simulation.The idea of hybrid simulation is that the non-linear part of the system that is difficult to model numerically is tested experimentally and the rest of the system is modeled numerically. Therefore two models are created – the experimental model and the analytical model. During the simulation both models are in strict cooperation in order to act like the undivided system.The following paper focuses on utilizing FPGA (field-programmable gate array) in the computations performed in the analytical model. FPGA is an integrated circuit that is configured by the user. Physically FPGA is an array of logic blocks that the user can program and reconfigure interconnects that will allow to connect logic blocks in the desired way in order to perform complex functions. The most important advantages of using FPGA are flexibility, highly parallel data processing (thanks to simultaneous operation of independent circuits), high efficiency and reliability. Therefore complex digital computations that are implemented to FPGA can be executed with great speed.In the presented research the non-experimental part of the mechanical system is modeled using Finite Element Method (FEM). In order to control the experimental model in a closed loop, the FEM computations must be performed in real time. As FEM is computationally demanding method, the computations must be conducted as efficiently as possible in order to enable real-time without losing accuracy. The following paper describes increasing the time performance of the hybrid simulation algorithm by executing it on the microprocessor of a microcontroller equipped with real-time operating system while performing the most computationally demanding operations on the FPGA.

Abstract: The work presents simulation method of dynamic properties used as assistance in the construction process of suspension systems for high-speed tracked vehicles. Special consideration has been given to the real-time coupling of virtual models with the dynamic response of actual elastic-damping elements of the vehicles. An original design method has been proposed. The method is characterized by the fact that each of the design stages are not performed sequentially, but are parallel to each other and that at each level, mutual coupling between the tasks of the design process occurs. The proposed simulation method using the dSpace system is based on the integration of virtual environment such as LMS Virtual Lab or MATLAB/Simulink with the actual object such as a damper, by means of dedicated input/output devices operating in real time. The method developed in the work allowed for an extension of the classic co-simulations, that is, simulations in two coupled virtual environments, to include an actual component or, rather – its dynamic – often non-linear – characteristic, its response to excitation. The method developed in the work allowed for an extension of the classic co-simulations, that is, simulations in two coupled virtual environments, to include an actual component or, rather – its dynamic – often non-linear – characteristic, its response to excitation.The developed test method and the computer programs have been verified by means of experimental measurements of the dynamic characteristics of the actual object during test-ground tests and in the laboratory. The obtained results of the simulations and experiments allow to confirm the validity of the assumed thesis, which has been included in the summary.

Abstract: The article presents the results of the synthesis of universal mathematical model of the excitation system of synchronous machines that can adequately reproduce a variety of excitation systems with different regulation laws. The information about the practical verification of the mathematical model is given in the paper.

Abstract: This article summarizes the results of an analytical review of usage in Russian and the world information and telecommunications decision support systems for dispatching personnel of electric power systems (ITDSS DP EPS). The need for a fundamentally new and effective ITDSS DP EPS has been identified. A comparative evaluation of the effectiveness of the possible directions of research in the field of ITDSS DP EPS has been done. As the key methods for development of ITDSS DP EPS the numerical and hybrid approaches to electric power system (EPS) simulation were highlighted. Theoretical substantiation of unacceptability of the first variant allowed choosing the hybrid approach as a major which allows developing and applying the most effective methods, ways and means for every significant aspect of the problem of creation of ITDSS DP EPS. In accordance with this approach, two possible constructions of ITDSS DP EPS have been proposed, discussed and described briefly in the article.

Abstract: The analysis of existing problem of reliability and verification of simulation tools of electrical power systems is presented in this article. It is proved, that the solution of this problem is not possible by using simulation tools utilizing numerical methods. Described the concept and tools are based on alternative way of electrical power systems simulation called the hybrid simulation. This way provides an effective solution to the problem of reliability and verification simulation tools of electrical power systems.

Abstract: Power system dynamic simulation is an effective way to fully grasp the power system dynamic response, and it is also the basis guiding power system planning, design and operation. The operation of the generator characteristics determines the dynamic characteristics of the power system to some extent, so enhancing the accuracy of generating set model parameters has great significance on improving the reliability of power system dynamic simulation. Due to the operation of the power system characteristics and special requirements on the safe and stable operation, we cannot understand its correctness of dynamic response by means of exerting disturbance test, which limits the simulation error evaluation work of the generating set. PMU data from effective disturbance scenarios is used in this paper to study the realization of the generator speed control system of hybrid simulation technology based on data measured by PMU. The corresponding hybrid simulation program is developed by using C++. The evaluation of speed regulation system error of the model parameters is realized on the basis of the simulation error index. The validity of speed control system model parameter error evaluation methods is proved by PMU data measured from disturbance scenarios of four Units in an area.

Abstract: In this article we will focus on creating of testbed based on hybrid real-time power system simulator (HRTSim) for setting up and testing of relay protection (RP), automatic (AS) and control systems (CS), as well as the opportunities and prospects of its application. The simulator has physical outputs, which allows using it for close-loop testing of RP, AS and CS. Physical currents and voltages generated in the simulator during a simulation process can be transmitted to the analog inputs of tested device by means of external amplifiers. There are no restrictions on the dimension of the simulated power system and time interval for HRTSim. These opportunities and usage of adequate models of primary and auxiliary power system equipment allows reducing the number of possible equivalenting and creating as closely as possible to the real conditions for setting up and testing of any RP, AS and CS, including wide-area protection and control systems.

Abstract: The ship autopilot can't work properly on the land due to the lack of the real rudder angle and heading feedback signal. The paper established the ship motion mathematic model and designed a rudder angle generating device. Applying the real autopilot, a detection and simulation system is developed. The proposed system can connect the output data between the ship autopilot and ship motion mathematic model, then the real ship autopilot performance can be detected and evaluated.

Abstract: The paper build the large region grid model of ultra-high voltage in electro-magnetic and electro-mechanical hybrid simulation system, and researched the effectiveness of ultra-high voltage transmission line to large region grid, especially the N-1 short tripping fault caused transient stability problems.