Selective harmonic-compensation control for single-phase active power filter with high harmonic rejection

(c) 2009 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.This paper presents a linear current control scheme for single-phase active power filters. The approach is based on an outer voltage loop, an inner current loop, and a resonant selective harmonic compensator. The design of the control parameters is carried out using conventional linear techniques (analysis of loop gain and other disturbance-rejection transfer functions). The performance of the proposed controller is evaluated and compared with two reference controllers: a basic control and an advanced repetitive control. In comparison with these controllers, the proposed control scheme provides additional attenuation to the harmonics coming from the load current, the grid voltage, and the reference signal, resulting in a grid current with lower harmonic distortion. Experimental results are reported in order to validate this paper.Peer ReviewedPostprint (updated version

A 0.1–5.0 GHz flexible SDR receiver with digitally assisted calibration in 65 nm CMOS

© 2017 Elsevier Ltd. All rights reserved.A 0.1–5.0 GHz flexible software-defined radio (SDR) receiver with digitally assisted calibration is presented, employing a zero-IF/low-IF reconfigurable architecture for both wideband and narrowband applications. The receiver composes of a main-path based on a current-mode mixer for low noise, a high linearity sub-path based on a voltage-mode passive mixer for out-of-band rejection, and a harmonic rejection (HR) path with vector gain calibration. A dual feedback LNA with “8” shape nested inductor structure, a cascode inverter-based TCA with miller feedback compensation, and a class-AB full differential Op-Amp with Miller feed-forward compensation and QFG technique are proposed. Digitally assisted calibration methods for HR, IIP2 and image rejection (IR) are presented to maintain high performance over PVT variations. The presented receiver is implemented in 65 nm CMOS with 5.4 mm2 core area, consuming 9.6–47.4 mA current under 1.2 V supply. The receiver main path is measured with +5 dB m/+5dBm IB-IIP3/OB-IIP3 and +61dBm IIP2. The sub-path achieves +10 dB m/+18dBm IB-IIP3/OB-IIP3 and +62dBm IIP2, as well as 10 dB RF filtering rejection at 10 MHz offset. The HR-path reaches +13 dB m/+14dBm IB-IIP3/OB-IIP3 and 62/66 dB 3rd/5th-order harmonic rejection with 30–40 dB improvement by the calibration. The measured sensitivity satisfies the requirements of DVB-H, LTE, 802.11 g, and ZigBee.Peer reviewedFinal Accepted Versio

Future work on harmonics : some expert opinions part I : wind and solar power

A workshop on power system harmonics was organized in Stockholm in January 2014. On the agenda was among others a discussion on what are the main issues on harmonics at the moment and in the near future. The results of this discussion are summarized in this paper and some of the issues are discussed in more detail in this paper and in its companion paper. This paper discusses emission from wind and solar power as well as advantages and disadvantages of active and passive filters

Fast selective harmonic mitigation in multifunctional inverters using internal model controllers and synchronous reference frames

This paper presents a fast selective harmonic current mitigation strategy for inverters with active power filter capabilities based in synchronous reference frames and twodegrees-of-freedom internal model controllers. The advantage of this control strategy over the conventional PI solution is a significant increase in the speed of harmonic detection and mitigation. Furthermore, this control strategy reduces the computational burden when applied in a digital controller. These characteristics make this strategy desirable for applications where fast/harmonic detection and mitigation are needed. Mathematical analysis and simulations are presented to corroborate the performance of the proposed controller strategy. Finally, the results of this proposal are verified in a 1kW 3-phase multifunctional inverter with harmonic compensation capabilities up to the 17th harmonic

Dynamic behavior of current controllers for selective harmonic compensation in three-phase active power filters

Current regulators are a critical part of active power filters (APFs). The design of current regulators capable of compensating high-frequency harmonics created by nonlinear loads is a challenging task. Selective harmonic current compensation using harmonic regulators is a viable method to achieve this goal. However, their design and tuning is not an easy task. The performance-and even the stability-of harmonic current regulators strongly depends on implementation issues, with the tuning of the controller gains being critical. Furthermore, the presence of multiple current regulators working in parallel can create unwanted couplings with the fundamental current regulator, which can result in a deterioration of APF current control, i.e., oscillations and settling times larger than expected. This paper addresses the design and tuning of selective harmonic compensators, with a focus on their stability analysis and transient behavio

Stationary frame voltage harmonic controller for standalone power generation

The paper presents a new control scheme for voltage control of voltage source inverter (VSI) with LC output filter. Proposed high performance control scheme with use of stationary regulators can be used in UPS or standalone power generation where sine wave output voltage is to be maintained. The proposed controller is able to compensate voltage distortion from unbalanced and nonlinear loads, thus controlling negative and positive voltage sequence and its harmonics. For the control purpose only voltage measurement in required. Besides, the controller can be further used in distributed power generation where the parallel operation is desired. In order to improve the parallel operation and sharing any kind of distorting loads, the proposed controller allows adjusting the gain of selected harmonics required for proper harmonic sharing. The proposed scheme is fully appropriate for digital implementation of UPS systems where high quality AC output voltage is in importance. The diagram block of the proposed controller is shown together with some simulation and experimental results. Presented controller shows outstanding performance under nonlinear and unbalanced loads which uses selective harmonic compensators

Study the Robustness Active Filter for a Three-Phase Power Rectifier Considering Line Frequency and Load Variations

ان مغيرات الكترونيات القدرة والتي يكون مبدأ عملها هو التغيير والتقويم تنتج التوافقيات التي تقوم بتشويه موجة الفولتية والتيار لمصدر تجهيز القدرة. عدة بحوث منشورة سعت الى استخدام تقنيات مختلفة لتقليل التوافقيات ومنها:(1- المرشحات الخاملة, 2- مغيرات حقن التيار, 3- المرشحات الفعالة, 4- المرشحات الهجينة). تستخدم المرشحات الفعالة بصورة واسعة مع المقومات ثلاثية الطور لتقليل التوافقيات باستخدام عناصر خاملة مع مفاتيح دوائر الكترونيات القدرة. يتناول هذا البحث خصائص المرشح الفعال عند تغيير تردد المصدر والحمل. حيث لوحظ ان قيمة التشوه التوافقي الكلي THD هي دائما عند الحد المسموح به (اقل من 5%) للمرشح الفعال, اما للمرشح الخامل فأن قيمة THD هي اعلى من 5% وخصوصاً لموجة التيارات عند تغيير تردد المصدر وان المرشح فقط يعمل عند التردد المصمم عنده (50Hz), وايضاً, في حالة تغيير الحمل من الحمل التام الى نصف الحمل فأن استجابة المرشح الفعال يكون اسرع من المرشح الخامل. تم استخدام تقنية المسيطر التخلفي الهستيري لتوليد نبضات المرشح الفعال. نتائج المحاكاة تبين اعلى قيم THD  للتيارات في الحالات: بدون استخدام اي مرشحات، استخدام المرشحات الخاملة واستخدام المرشحات الفعالة هي كالتالي: 24.36% ، 80.79% و 3.03%.Power electronic converters (e.g. AC-DC and DC-AC) produce harmonics which distorting the waveforms of voltage and current. Many research works have examined various techniques to mitigate harmonics at operating conditions (i.e. at a fixed line frequency and a specific load) such as: (i) passive filters, (ii) Current-injection converters, (iii) active filters and (iv) hybrid filters. Active filters are widely used with three-phase bridge rectifiers due to their excellent features for reducing harmonics using power switches instead of passive components that minimize the efficiency of the system. This paper investigates the robustness and the dynamic performance of active filters under the variation of line frequency and DC load. In case of using active filters, it is observed that total harmonic distortion (THD) of voltage and current waveforms is kept at IEEE Standard limits (i.e. less than 5%)  under the variation of line frequency . Whilst the performance of passive filters is highly affected by the variations of line frequency and THD of voltage and current waveforms is always greater than 5% except at designed frequency, i.e. 50 Hz. Moreover the load is changed from full-load to half-load, it is observed that the dynamic response of active filters is faster than passive filters for canceling harmonics. It is worth noting that the hysteresis-current-control method is utilized for adjusting the control pulses of active filters due to its rapid dynamic responsem. Simulation results present the highest values of THD of line currents in cases: without any filters , passive filters and active filters are 24.36%, 80.79% and 3.03%, respectively