• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.498-501
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• 1994

This paper presents a digital calculation method of instantaneous reactive power component for standby power supply(SPS) system. Reactive current is defined in time domain, calculated instantaneously by using a TMS320C25. The theoretical analysis is verified by the digital simulation and experimental results.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.934-935
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• 2015

This paper presents the sensorless control method that employs the adaptive back-EMF(Electromotive Force) and current model observer of interior permanent magnet synchronous motor(IPMSM). The estimated back EMF considering a saliency is obtained by using the adaptive control method. The estimated EMF is inputted to the current model observer which is connected in series with adaptive back EMF estimator and is used to estimate the position and speed of the rotor. In order to improve the shortcomings of conventional method using the current error components multiplied in the compensation constant, the modified instantaneous reactive power compensator is applied. The validity of the control system presented is verified by the simulation.

• 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).

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.475-478
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• 2004

본 논문에서는 부하단에서 발생하는 고조파를 검지하는 방법으로 순시 무효전력 방법(IRPM: Instantaneous Reactive Power Method)을 사용하였다. 이 방식은 DQ변환을 통해 순시 무효 전력을 사용하여 고조파를 검지하는 방식이다. 그러나 순시 무효전력 방식은 3상 인버터를 기반으로 하는 DQ변환 방식을 이용하기 때문에 단상 시스템에는 적용될 수 없다. 본 논문에서는 단상에서도 임의의 가상축을 만들어 DQ변환을 수행할 수 있도록 함으로써 순시무효전력 보상 방식을 단상 능동 전력 필터 시스템에도 적용될 수 있는 방안을 제시하였다. 또한 검지된 고조파를 효과적으로 보상할 수 있는 3레벨 NPC 타입 멀티레벨 인버터를 사용하여 고전력 능동 필터를 구성할 수 있도록 하였다.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.207-209
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• 2005

Recently, the use of IPMSM is coming to be active, in many industrial applications. In sensorless drive of IPMSM, it is important to know the exact information of the initial rotor position, because the wrong estimation of the initial rotor position brings about the decrease of the starting torque, or a temporary reverse revolution, In addition, PMSM is necessary to use the accurate information of the inductance for the precise torque control owing to the reluctance torque. In this paper presents initial rotor position estimation method and, measure method of the each-axis inductance. And to minimize the speed estimations error, the estimated speeds are compensated by using an instantaneous reactive power in synchronously rotating reference frame.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.6
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• pp.361-368
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• 2018

This paper proposes a grid - connected CTTS system that can be soft switched to meet the government's effective resource allocation policy for emergency generator. In order to eliminate the system instability caused by the large inrush current generation in the system switching, a new virtual rotation coordinate method for the dissimilar power source is proposed. The proposed virtual rotation coordinate method improves the voltage detection accuracy of the voltage difference of the dissimilar power supply, and it is proved that the synchronous switching characteristic is excellent. In addition, zero current and system stabilization can be achieved by realizing zero current when blocking CTTS with instantaneous reactive power control. Simulation was carried out to verify the validity of the proposed method, and the 500[kVA] system was fabricated and verified to demonstrate the superiority of the proposed method.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.237-239
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• 2001

This paper presents a new speed sensorless control method of permanent magnet synchronous motors based on instantaneous reactive power. The proposed system is constructed in a synchronously rotating reference frame and is very simple. The new approach is not dependent upon the stator resistance, nor is it affected by mechanical motor parameters. The effectiveness of the proposed system is confirmed by the simulation results.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.149-151
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• 2005

This paper deals with the novel control algorithm of single-phase hybrid active power filter for the compensation of harmonic current components in nonlinear R-L load with passive active power filters. To construct two-axes coordinate, an imaginary second phase was made by giving time delay to line current. In this proposed method, the new signal, which was the delayed through the filtering by the phase-delay property of low-pass filter, is used as the secondary phase. Because two phases have different phase, instantaneous calculation of harmonic current is possible. In this paper, a reference voltage is created by multiplying gain of filter by compensation current using the rotating reference frames that synchronizes with source-frequency, not applying to instantaneous reactive power theory which has been used with the existing fixed reference frames. This paper shows the experimental results, which provide a high accuracy and extremely fast response of single-phase hybrid active Bower filter under the operation with the proposed control method.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.214-216
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• 2005

IPMSM is necessary to use the accurate values of the inductance for the precise torque control, because of using the reluctance torque of the IPM. This paper presents method to uses the hysteresis loop inclination of the flux and current measured by applying the positive and negative voltage pulse alternately on the each-axis. Moreover, presents algorithm for speed sensorless control based on parameter identification and instantaneous reactive power.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1049-1051
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• 2001

This paper proposes a new control strategy of multifunctional uninterruptible power supply(UPS) with the performance of active power filter which compensate the harmonics and reactive power. To improve the transient response for the effective compensation in active power filter mode, it is considered that a simple and precise calculation method of the compensation reference current for the harmonics and reactive power compensation. So a novel closed-loop control strategy is used to calculate the reference current. And the current regulated instantaneous voltage control scheme is used in back-up power mode. The system model and control algorithm are described and analyzed, and the system performance is verified by the simulation results.