• Journal of Electrical Engineering and Technology
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• 제4권3호
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• pp.315-322
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• 2009

Penetration and installation of a new dynamic technology known as Flexible AC Transmission Systems (FACTS) in a practical and dynamic network requires and force expert engineer to develop robust and flexible strategy for planning and control. Unified Power Flow Controller (UPFC) is one of the recent and effective FACTS devices designed for multi control operation to enhance the power system security. This paper presents a dynamic strategy based on Particle Swarm Optimization (PSO) for optimal parameters setting of UPFC to enhance the system loadability. Firstly, we perform a multi power flow analysis with load incrementation to construct a global database to determine the initial efficient bounds associated to active power and reactive power target vector. Secondly a PSO technique applied to search the new parameters setting of the UPFC within the initial new active power and reactive power target bounds. The proposed approach is implemented with Matlab program and verified with IEEE 30-Bus test network. The results show that the proposed approach can converge to the near optimum solution with accuracy, and confirm that flexible multi-control of this device coordinated with efficient location enhance the system security of power system by eliminating the overloaded lines and the bus voltage violation.

• Smart Structures and Systems
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• 제22권1호
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• pp.81-94
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• 2018

Automatic Generation Control (AGC) has functionally controlled the interchange power flow in order to suppress the dynamic oscillations of frequency and tie-line power deviations as a perturbation occurs in the interconnected multi-area power system. Furthermore, Flexible AC Transmission Systems (FACTS) can effectively assist AGC to more enhance the dynamic stability of power system. So, Static Synchronous Series Compensator (SSSC), one of the well-known FACTS devices, is here applied to accurately control and regulate the load frequency of multi-area multi-source interconnected power system. The research and efforts made in this regard have caused to introduce the Fractional Order Proportional Integral Derivative (FOPID) based SSSC, to alleviate both the most significant issues in multi-area interconnected power systems i.e., frequency and tie-line power deviations. Due to multi-objective nature of aforementioned problem, suppression of the frequency and tie-line power deviations is formularized in the form of a multi-object problem. Considering the high performance of Multi Objective Bees Algorithm (MOBA) in solution of the non-linear objectives, it has been utilized to appropriately unravel the optimization problem. To verify and validate the dynamic performance of self-defined FOPID-SSSC, it has been thoroughly evaluated in three different multi-area interconnected power systems. Meanwhile, the dynamic performance of FOPID-SSSC has been accurately compared with a conventional controller based SSSC while the power systems are affected by different Step Load Perturbations (SLPs). Eventually, the simulation results of all three power systems have transparently demonstrated the dynamic performance of FOPID-SSSC to significantly suppress the frequency and tie-line power deviations as compared to conventional controller based SSSC.

• Journal of Power Electronics
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• 제17권3호
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• pp.766-776
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• 2017

In modern power systems, high penetration of distributed generators (DGs) results in high stress on system stability. Apart from the intermittent nature of DGs, most DGs do not contribute inertia or damping to systems. As a result, a new control method named virtual synchronous machine (VSM) was proposed, which brought new characteristics to inverters such as synchronous machines (SMs). In addition, different active power droop controls for VSMs are being proposed in literatures. However, they are quite different in terms of their dynamic characteristics despite of the similar control laws. In this paper, mathematical models of a VSM adopting different active power droop controls are built and analyzed. The dynamic performance of the VSM output active power and virtual rotor angular frequency are presented for different models. The influences of the damping factor and droop coefficient on the VSM dynamic behaviors are also investigated in detail. Finally, the theoretical analysis is verified by simulations and experimental results.

• Journal of Power Electronics
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• 제16권4호
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• pp.1598-1611
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• 2016

In some special occasions with strict size requirements, such as mine hoists, improving the design accuracy of the forced-air cooling systems of NPC three-level inverters is a key technology for improving the power density and decreasing the volume. First, a fast power-loss calculation method was brought. Its calculation principle introduced in detail, and the computation formulas were deduced. Secondly, the average and dynamic power losses of a 1MW mine hoist acting as the research target were analyzed, and a forced-air cooling system model based on a series of theoretical analyses was designed with the average power loss as a heat source. The simulation analyses proves the accuracy and effectiveness of this cooling system during the unit lifting period. Finally, according to an analysis of the periodic working condition, the maximum power-loss range of a NPC three-level inverter under multi cycle operation was obtained and its dynamic power loss was taken into the optimized cooling system model as a heat source to solve the power device damage caused by instantaneous heat accumulation. The effectiveness and feasibility of the optimization design based on the dynamic power loss calculation of the maximum power-loss range was proved by simulation and experimental results.

• 전기학회논문지P
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• 제54권4호
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• pp.224-229
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• 2005

This paper presents a bidirectional pulse power electrochemical etching system for groove manufacturing of the dynamic bearings. To manufacture the dynamic bearing for the groove, it is very important to consider the depth and roughness. If the precision of the groove is not exact, we can not get the desirable performance for the target of the dynamic bearing. To make the groove of bearing precise, we propose the method of electrochemical etching system. In order to design the depth and roughness exactly, the bidirectional pulse power converter is proposed. With the bidirectional pulse power converter, we obtain the condition and the parameters of converter such as frequency, duty ratio, time, temperature, velocity, pressure and so on. In this paper, we get the experimental results to verify the precise groove manufacturing.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.203-203
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• 2000

The P&S(Power Plant Simulation System) is a powerful simulation software system for the dynamic behavior of power plants. The P&S module libraries provide plant models with higher flexibility of dynamic simulations for process and control designs. The P&S software was effectively available for PCS based on Linux and modem workstations based on Unix. The P&S was applied for simulating the dynamic behaviors of the SOVR(Supercritical Once-Through Variable Pressure Reheater) according to the operations such as stan-up, shutdown, load following, load change and trip in order to obtain an optimal operation procedure for Unit 5/6 of Taeahn fossil power plant consisted of SOVRs and steam turbines.

• 한국인터넷방송통신학회논문지
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• 제8권2호
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• pp.49-55
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• 2008

To address the convergence issue of power control algorithms, a number of algorithms have been developed hat shape the dynamics of up-link power control for cellular network. Power algorithms based on fixed point iterations can be accelerated by the use of various methods, one of the simplest being the use of Newton iterations, however, this method has the disadvantage which not only needs derivatives of the cost function but also may be weak to noisy environment. we showed performance of the power control schemes to solve the fixed point problem under static or stationary channel. They proved goof performance to solve the fixed point problem due to their predictor based optimal control and quadratic convergence rate. Here, we apply the proposed power control schemes to the problem of the dynamic channel or to dynamic time varying link gains. The rigorous simulation results demonstrated the validity of our approach.

• Journal of Power Electronics
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• 제7권4호
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• pp.336-342
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• 2007

This paper presents the development of a fuel cell dynamic simulator using a programmable DC power supply and LabVIEW graphical user interface. The developed simulator closely describes the static and dynamic characteristics of an actual proton exchange membrance fuel cell (PEMFC). The experimental results are provided to verify the operation of the simulator. The developed simulator can be used as a convenient and economic alternative to an actual fuel cell for developing and testing a fuel cell power conditioning system.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.113-118
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• 1998

In modern mechatronics new concepts of machines and processes are found by using the collected knowledge of all disciplines and by offering functional solutions. Most of the problems in the field of mechatronics demand technical innovations on the field of actuators, sensors and control methods. It demands also high dynamic drives with power electronics, able to cope with the new requirements. The paper presents some trends and industrial experiences with power components for high dynamic drives.

• 전기의세계
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• 제24권5호
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• pp.67-71
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• 1975

A dynamic stability analysis of a large interconnected power system takes much time even though the modern large computer is used because of the high order of the system dynamic equations. By the necessity of the low order power system models, a simplified power system model of the generator with the high speed solid state exciter is developed in this paper. The usefulness of the reduced model is confirmed by comparing its eigenvalues and the transient responses with those of the original model in the single machine to infinite bus power system.