Earticle

In this paper, a new modular active power filtering approach is proposed to eliminate harmonic currents and compensate reactive power. The method for identifying reference currents is based on FMVs “multi-variable filter”. This method uses two (FMVs) having the advantage of extracting harmonic directly from the axis, the first FMV (FMV Current) extracts the fundamental and individual harmonic component of the distorted line current signal and injects equal-but- opposite of each harmonic current into the line using a voltage source inverter VSI dedicated to that specific harmonic and the second FMV (FMV Voltage) estimates the fundamental component of the line voltage. Moreover the dc-side voltage is controlled by a fuzzy logic controller. The new approach has been illustrated in order to find the best way to reduce network harmonic currents and reactive power compensating of the connected load. All of the studies have been carried out through detail digital dynamic simulation using the MATLAB/Simulink Power System Toolbox.

In this paper, three phase four wire active power filter is proposed to eliminate harmonic currents both in the phases and in the neutral conductor of un unbalanced three-phase four wire electrical distribution system, feeding three single non-linear loads. A new method for identifying reference currents will be developed. It is based on pq theory using two improvements: multi-variable filter having the advantage of extracting harmonic voltages directly from the  axis and the second improvement consists on the use of fuzzy logic controller to extract current harmonics components. A comparison between classical method and the new approach has been illustrated in order to find the best way to reduce network harmonic currents. The Matlab numerical code is used for all simulations in this paper.

본 논문에서는 텔레메트리 시스템을 위한 가변 컷 오프 주파수 및 가변 샘플레이트 특성을 지니는 저면적 다채널 디지털 필터구조를 제안한다. 제안하는 디지털 필터는 임의의 컷 비율에 대해 필터 뱅크의 추가적인 설계 없이 컷 오프 주파수와 샘플레이트를 가변적으로 사용할 수 있는 필터 뱅크를 구현함으로써 하드웨어 면적을 줄일 수 있었다. 또한, 멀티플렉서 (MUX; Multiplexer) 컨트롤을 통해 통과하는 필터의 개수에 따라 샘플레이트를 가변적으로 선택할 수 있는 구조를 제안한다. 제안하는 디지털 필터는 Quartus의 FIR (finite impulse response) IP (intellectual property)의 TDM (time division multiplexing)을 이용함으로써, TDM을 사용하지 않았을 때보다 면적이 큰 DSP (digital signal processing) 블록을 80개에서 1개로 줄일 수 있었다. Kaiser 창 함수를 이용하여 Matlab을 통해 필터의 차수와 계수를 계산하였으며, VHDL (very high speed integrated circuits hardware description language)을 통해 하드웨어로 구현하였다. 텔레메트리 시스템에 적용 후, 실험 결과를 통해 제안하는 디지털 필터가 정상적으로 동작하고 있음을 확인하였다.

In this paper, We propose variable cut-off frequency and variable sample rate small-area multi-channel digital filter for telemetry system. Proposed digital filter reduced hardware area by implementing filter banks that can variably use cut-off frequency and sample rate without additional filter banks for an arbitrary cut ratio. In addition, We propose the architecture in which sample rate can variably be selected according to the number of filters that pass through the multiplexer control. By using time division multiplexing (TDM) supported by the finite impulse response (FIR) intellectual property (IP) of Quartus, the proposed digital filter can greatly reduce digital signal processing (DSP) blocks from 80 to 1 compared without TDM. Proposed digital filter calculated order and coefficients using Kaiser window function in Matlab, and implemented using very high speed integrated circuits hardware descryption language (VHDL). After applying to the telemetry system, we confirmed that the proposed digital filter was operating through the experimental results in the test environment.