• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.3
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• pp.49-58
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• 2000

This paper deals with a systematic approach to neural network controller design for static VAR compensator (SVC) using a learning algorithm of error back propagation that accepts error and change of error as inputs, the momentum learning technique is used for reduction of learning time, to improve system stability. A SVC, one of the Flexible AC Transmission System(FACTS), constructed by a fixed capacitor(FC) and a thyristor controlled reactor(TCR), is designed and implemented to improve the damping of a synchronous generator, as well as controlling the system voltage.TO verify the robustness of the proposed method, we considered the dynamic response of generator rotor angle deviation, angular velocity deviation and generator terminal voltage by applying a power fluctuation and rotor angle fluctuation in initial point when heavy load and normal load. Thus, we prove the usefulness of proposed method to improve the stability of single machine-infinite bus with SVC system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.26-31
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• 2017

The conventional method of improving the transient stability in a power system is the use of reactive power compensation devices, such as the STATCOM and SVC. However, this traditional method cannot prevent the rapid voltage collapse brought about by the stalling of the motor due to a system fault. On the other hand, the ESS (Energy Storage System) provides fast-acting, flexible reactive and active power control. The fast-acting power compensation provided by an energy storage system plays a significant role in enhancing the transient stability after a major fault in the power system. In this paper, a method of enhancing the transient stability using an energy storage system is proposed for power systems including a dynamic load, such as a large motor. The effectiveness of the energy storage system compared to conventional devices in enhancing the transient stability of the power system is presented. The results of the simulations show that the simultaneous injection of active and reactive power can enhance the transient stability more effectively.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.6
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• pp.40-50
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• 2002

In this paper, we present a GA(Genetic Algorithm) approach to select weighting matrices of an optimal LQ(Linear Quadratic) controller for SVC(Static VAR Compensator). A SVC, one of the FACTS(Flexible AC Transmission System), constructed by a FC(Fixed Capacitor) and a TCR(Thyristor Controlled Reactor), was designed and implemented to improve the damping of a synchronous generator, as well as to control the system voltage Also, a design of LQ controller depends on choosing weighting matrices. The selection of weighting matrices which is not a trivial solution is usually carried out by trial and error. We proposed an efficient method using GA of finding weighting matrices for optimal control law. Thus, we proved the usefulness of proposed method to improve the stability of single machine-infinite bus with SVC system by eigenvalues analysis and simulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.592-597
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• 2019

A conventional method to improve transient stability in power system is the use of reactive power compensation devices such as STATCOM and SVC. However, this traditional method cannot prevent a rapid voltage collapse brought on by motors stalling due to system fault. On the other hand, ESS(Energy Storage System) provides fast-acting, flexible reactive and active power control. The fast active power compensation with energy storage system plays a significant role in transient stability enhancement after a major fault of power system. In this paper, transient stability enhancement method by using energy storage system is proposed for the power system including a dynamic load such as large motor. The effectiveness of energy storage system compared to conventional devices in enhancing transient stability of power system is presented. The results of simulations show that the simultaneous injection of active and reactive power can enhance more effectively transient stability.

• Journal of Power Electronics
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• v.15 no.3
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• pp.830-840
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• 2015

The H-bridge inverter is the fundamental power cell of the cascaded distribution static synchronous compensator (DSTATCOM). Thus, cell reliability is important to the compensation performance and stability of the overall system. The concept of the power electronics building block (PEBB) is an ideal solution for the power cell design. In this paper, an H-bridge inverter-based “plug and play” HPEBB is introduced into the main circuit and the controller to improve the compensation performance and reliability of the device. The section that discusses the main circuit primarily emphasizes the design of electrical parameters, physical structure, and thermal dissipation. The section that presents the controller part focuses on the principle of complex programmable logic device -based universal controller This section also analyzes typical reliability and anti-interference issues. The function and reliability of HPEBB are verified by experiments that are conducted on an HPEBB test-bed and on a 10 kV/± 10 Mvar DSTATCOM industrial prototype.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.79-80
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• 2013

MMC(Modular Multilevel Converter)는 여러 개의 Power Module을 직렬로 연결하여 정현파에 가까운 고전압의 파형을 얻을 수 있는 토폴로지로 대용량 전력변환 분야의 요구를 만족하면서 전력 품질을 향상시킬 수 있어 근래에 상당히 주목받고 있다. 당사에서는 5Mvar급 STATCOM(STATic synchronous COMpensator)을 MMC 형태로 제작하였다. 제작된 5Mvar급 STATCOM은 한 상당 12대의 Power Module로 구성하여 25-Level로 제작되었다. 제어시스템은 DSP(Digital Signal Processor)를 이용하였으며, 하나의 Main Controller와 다수의 Cell Controller, FPGA 보드 등으로 구성되어 있다. Controller 간의 상호 정보를 교환하기 위해 CAN 통신을 이용하였고, Power Module의 스위칭을 위한 보드는 각각에 연결되어 있으며, Cell Controller보드와는 절연을 위해 광신호로 연결하였다. 본 논문에서는 MMC 시스템의 제어기간 CAN 통신인터페이스와 Power Module의 PWM 동기화에 대해 설명을 하였다.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.5
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• pp.250-256
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• 2003

In this papur, the STATCOM (STATic synchronous COMpensator) application for efficient operations of wind farm is described. The wind farm connected with the electric power network is one of good alternative energy sources. However, it would be also highly possible that interconnection of wind farm causes unwanted influences on distribution system operation, protection and control. This paper proposes the STATCOM application for reducing the negative effects from interconnection of wind farm with distribution networks. The simulation results show that STATCOM would be on effective and useful device to resolve the bad influences from wind farm on distribution networks and improve the operational efficiency of wind farm. In the simulation, the radial distribution network of IEEE 13 bus was modeled using PSCAD/EMTDC.

• Journal of Energy Engineering
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• v.13 no.1
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• pp.68-74
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• 2004

This paper presents the design of DSTATCOM (Distribution Static Synchronous Compensator) controller. The results are verified by using PSCAD/EMTDC package. The state equation derived by decomposition analysis of DSTATCOM current component is applied to load model and the combined model which considered constraint condition. In case of single line to ground fault, the conventional method of Pl control is compared with LQR control technique. LQR control is shown to be superior in terms of response profile and composition of voltage sag.

• Journal of Electrical Engineering and Technology
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• v.6 no.2
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• pp.182-191
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• 2011

Genetic algorithms (GA) and particle swarm optimization (PSO) are the most famous optimization techniques among various modern heuristic optimization techniques. These two approaches identify the solution to a given objective function, but they employ different strategies and computational effort; therefore, a comparison of their performance is needed. This paper presents the application and performance comparison of the PSO and GA optimization techniques for a static synchronous series compensator-based controller design. The design objective is to enhance power system stability. The design problem of the FACTS-based controller is formulated as an optimization problem, and both PSO and GA optimization techniques are employed to search for the optimal controller parameters.

• Journal of Power Electronics
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• v.1 no.1
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• pp.48-55
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• 2001

This paper describes a switching-level simulation model and scaled hardware model for SSSC, which is useful for analyzing the dynamic interaction between the SSC and the power transmission system. A detailed simulation model with EMTP was developed to verity the SSSC operation with control system, and its increasing capability of power transmission through the line for a typical one-machine infinite-bus system. The simulation results of the developed model are compared with the experimental results froma scaled model fo 2KVA rating for evaluation the whole system operation.