• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.6
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• pp.678-682
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• 1999

In this paper, we propose the algorithm which can control active power and reactive power independently in Battery Energy Storage System. The proposed algorithm is based on the instantaneous power theory that the inner product of the voltage vector and current vector represents the active power and the cross product of those represents the reactive power, and it can control active power and reactive power independently. To verify the validity of the proposed algorithm, we make model of the real power system in th KERI and simulate this algorithm. As a result of this simulation, we verified that the proposed algorithm can control active power and reactive power independently.

• Journal of Electrical Engineering and information Science
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• v.2 no.4
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• pp.46-52
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• 1997

In this paper th use of compensation based on a combination of active plus reactive power at distribution model system is proposed. The basic voltage-power relationships for the linearized case on an infinite bus are used and the compensation angle is defined based on the voltage magnitude response to small power injection. Compensation is supplied at several locations, and the system is subjected to varying fault scenarios, with its response observed under different system conditions. As number of control issues for a storage-based active/reactive power compensator as a bus voltage regulator are explored to compare the effectiveness of active/reactive again reactive-only compensation.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.33 no.10
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• pp.410-422
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• 1984

This paper presents a new practical method for optimal active and reactive power control for the economic operation in electrical power system, and the programs are developed for digital computer solution. The major features and techniques of this paper are as follows: 1) The method is presented for finding the equivalent active power balance equation applying the sparse Jacobian matrix of power flow equation instead of using B constant as active power balance equation considering transmission loss, and thus for determining directly optimal active power allocation berween generator unitw satisfying the equality and inequality constraints. 2) The method is proposed for solving directly the optimum economim dispatch problem without using gradient method and penalty function for both active and reactive power control. As a result, the computing time are reduced and convergence characteristic is remarkably improved. 3) Unlike most of conventional methods which adopt the transmission loss as a objective function for reactive power control, the total fuel cost of themal power plant is adopted as objective function for both active and reactive power control. consequently, more reasonable and economic profit can be achieved.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1351-1354
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• 2002

Wind farm which are composed with wind turbine generators can be a good alternatives to solve environmental problem and solutions to cope with energy crisis for using wind energy. Until now, these wind turbine generators have been being studied on the viewpoint of only active power control for reducing the burden of main grid. In this control scheme, we might demand a reactive power compensator in order to make reparation for the reactive power produced from wind turbine generator itself. Therefore, if the reactive power as well as active power of wind turbine generator were controlled according to the demand of reactive power, the installation of a additional reactive power compensator could be reduced. This paper presents the control method of a active and reactive power for wind turbine generators by means of SVPWM(Space Vector Pulse Width Modulation) inverting method and describes a operational coordination of wind turbine generators. The proposed power control algorithm can simply produce the output power of wind turbine generator needed in wind farm, which can reduce the power of main grid more and exclude a supplementary reactive power compensator. We assumed that wind farm are composed with two kinds of wind turbine generators, AC/DC/AC and induction generator types.

• Journal of Power Electronics
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• v.16 no.5
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• pp.1918-1927
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• 2016

This paper proposes active frequency drift (AFD) as an anti-islanding method applied to micro-inverters with uncontrollable reactive power. When using ordinary inverter topologies, such as full bridge inverters in photovoltaic systems, the islanding phenomenon can be detected with reactive power-based methods, such as reactive power variation. However, when the inverter topology cannot control the reactive power, conventional anti-islanding methods with reactive power cannot be utilized. In this work, the topology used in this paper cannot control the reactive power. Thus, an anti-islanding method that can be used in topologies that cannot control the reactive power is proposed. The conventional anti-islanding method of the topology that cannot control reactive power is introduced and analyzed. Unlike the conventional AFD method, the proposed method extends a zero current interval every predetermined cycle. The proposed method offers certain advantages over conventional AFD methods, such as total harmonic distortion. The proposed method is validated through simulation and experiment.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.213-214
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• 2014

This paper compares two instantaneous reactive power definitions in DFIG wind turbine with a back-to-back three-level neutral-point clamped voltage source converter under unbalanced grid conditions. In general, conventional definition of instantaneous reactive power is obtained by taking an imaginary component of complex power. The other definition of instantaneous reactive power can be developed based on a set of voltages lagging the grid input voltages by 90 degree. A complex quantity referred as a quadrature complex power is defined. Proposed definition of instantaneous reactive power is derived by taking a real component of quadrature complex power. The characteristics of two instantaneous reactive power definitions are compared using the ripple-free stator active power control algorithm in DFIG. Instantaneous reactive power definition based on quadrature complex power has a simpler current reference calculation control block. Ripple of instantaneous active and reactive power has the same magnitude unlike in conventional definition under grid unbalance. Comparison results of two instantaneous reactive power definitions are verified through simulation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.4
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• pp.127-133
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• 1999

Ths paper deals with the active and reactive power control of Battery Energy Storage System (BESS) during its interconnection operation to power distribution system When an interconnection operation of BESS to power distribution system, it is well suited for peak load shaving and distribution voltage compensation by controlling the real and reactive power. Equivalent mxiel of the distribution system and the BESS is derived and power flow equations are presented to control the real and reactive power of BESS. In this paper, to control the active and reactive power of BESS, $P-\delta$ and Q-V control method and ntJIrerical description is presented. To verify the proposed control method, using PSCAD/EMTDC program simulates the active and reactive power control of BESS.f BESS.

• Journal of Power Electronics
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• v.18 no.6
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• pp.1634-1641
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• 2018

This study focuses on a high-performance direct active and reactive power controller design that is successfully applicable to three-phase pulse width modulation (PWM) AC/DC converters used in renewable distributed energy generation systems. The proposed controller can overcome the sluggish transient dynamic response of conventional controllers to rapid power command changes. Desired active and reactive powers can be thoroughly obtained at the end of each PWM period through a deadbeat solution. The proposed controller achieves an exact nonlinear cross-coupling decoupling of system power without using a predefined switching table or bang/bang hysteresis control. A graphical and analytical analysis that naturally leads to a control voltage vector selection is provided to confirm the finding. The proposed control strategy is evaluated on a 3 kW PWM AC/DC converter in the simulation and experiment.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.5
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• pp.438-444
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• 2012

This paper deals with the active and reactive power control of Grid connected system. It was shown that active power and reactive power can be dependently controlled with two individually adaptable parameters. The two parameters are power angle and voltage magnitude. Transient state will occur with active or reactive power reference value variation. This paper presents a new control strategy for active and reactive power control of less interaction and improved transient response. The paper details the control technique by the mathematical and electrical network analysis of the methodology. The performance was verified through computer simulation using MATLAB Simulink and experiment.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1124-1136
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• 2017

Direct Power Control technique has become popular in the grid connected Voltage Source Converter (VSC) applications due to its simplicity, direct voltage vector selection and improved dynamic performance. In this paper, a direct method to determine the effect of voltage vector on the instantaneous active and reactive power variations is developed. An alternative Look Up Table is proposed which minimizes the commutations in the converter and results in minimum reactive power variation. The application of suggested table is established for Shunt Active Power Filter (SAPF) application. The Predictive Direct Power Control method, which minimizes apparent power variation, is further investigated to reduce commutations in converters. Both the methods are validated using 2 kVA laboratory prototype of Shunt Active Power Filters (SAPF).