Performance Investigation of Shunt Hybrid Active Power Filter With A Synchronous Reference Frame BasedController

ABSTRACT:  

This paper presents a novel synchronous reference frame based (SRF) control strategy for shunt hybrid active power filter (SHAPF). The control strategy includes a direct current control (DCC) and an indirect current control (ICC) strategy. SHAPF can achieve harmonic compensation and dynamic reactive power compensation with the proposed controller.

In this proposed method, as distinct from studies in literature, dynamic reactive power compensation and dc link voltage control is realized with ICC and harmonic current compensation is realized with DCC. Also, the proposed controller provides a variable SHAPF dc link voltage which is adjusted according to the reactive power compensation requirements in order to decrease the switching losses of converter and achieve power savings. The performance of proposed controller is verified with experimental results.

KEYWORDS:

  1. Active Power Filter (APF)
  2. Harmonics
  3. Reactive Power Compensation
  4. Direct Current Control
  5. Indirect Current Control

 SOFTWARE: MATLAB/SIMULINK

 CIRCUIT DIAGRAM:

Fig. 1. Power Circuit Diagram of SHAPF

 EXPECTED SIMULATION RESULTS:

(a)

(b)

Fig.2. Reactive Power Trend (a) and Current Harmonic Spec. (b) of Case I

(a)

(b)

Fig.3. Reactive Power Trend (a) and Current Harmonic Spec. (b) of Case II

CONCLUSION:

 This paper presents a SRF based controller approach for SHAPF. In proposed control method, DCC strategy is preferred for harmonic compensation control to maintain superior dynamic and steady state performance on the compensation of low order harmonics. ICC strategy is used for the reactive power compensation controller and the dc link voltage controller to simplify the controller and provide a successful performance without being affected by dynamic changes in active and reactive current components.

Additionally, the dc link voltage is determined with adaptive to the reactive power demand of load by the proposed control method. By the help of this ability, the switching losses of SHAPF is decreased by keeping only required voltage level on dc link. The proposed control method is applied on the laboratory prototype of SHAPF. The steady state and dynamic performance of controller is verified with the experimental results.

REFERENCES:

[1] H. Fujita and H. Akagi, “A practical approach to harmonic compensation in power systems-series connection of passive and active filters,” IEEE Trans. Ind. Appl., vol. 27, no. 6, pp. 1020–1025, 1991.

[2] H. Akagi, “Active and hybrid filters for power conditioning,” ISIE’2000. Proc. 2000 IEEE Int. Symp. Ind. Electron. (Cat. No.00TH8543), vol. 1, 2000.

[3] H. Fujita, T. Yamasaki, and H. Akagi, “A hybrid active filter for damping of harmonic resonance in industrial power systems,” IEEE Trans. Power Electron., vol. 15, no. 2, pp. 215–222, Mar. 2000.

[4] S. Srianthumrong and H. Akagi, “Medium-voltage transformerless ac/dc power conversion system consisting of a diode rectifier and a shunt hybrid filter,” IEEE Trans. Ind. Appl., vol. 39, no. 3, pp. 874–882, May 2003.

[5] R. Inzunza and H. Akagi, “A 6.6-kV Transformerless Shunt Hybrid Active Filter for Installation on a Power Distribution System,” IEEE Trans. Power Electron., vol. 20, no. 4, pp. 893–900, Jul. 2005.

Design of a SRF Based MC UPQC Used for Load Voltage Control in Parallel Distribution Systems

ABSTRACT:

This paper manages another plan dynamic model of synchronous-reference-outline (SRF)- based control in three stage framework under various load contemplations to enhance control quality by utilizing power conditioner with multi converters. The proposed MCUPQC framework can control the heap voltages/transport voltages on Parallel power appropriation frameworks under adjusted and contorted load conditions and acquire the state space demonstrate for MC-UPQC. The reenactment results to help the SRF-based control strategy displayed in this paper is finished utilizing Matlab/Simulink.

  

BLOCK DIAGRAM:

Fig.1.The single line diagram of conventional MC-UPQC

 

 EXPECTED SIMULATION RESULTS:

Fig. 2.a and b. the phase bus voltage, VS1 and load voltage VL1

Fig. 3.c and d. the phase bus voltage, VS2 and load voltage VL2

Fig.4.a & b. the phase Source Current, IS1 and Load CurrentIL1

Fig. 5 and 6 .a, b and c. The phase bus voltage, injected voltage and load Voltages

Fig. 7.a, b and c. The phase Source Currents (IS1), load Currents (IL1) and DC Capacitor Voltage(VDC).

Fig. 8.a, b, c, d, e and f. the phase bus voltage (VS1), load Voltages (VL1), load Voltages (VL2), the phase source currents (IS1), load Currents (IL1) and DC Capacitor Voltage (VDC).

  

CONCLUSION:

In this paper the SRF Based control MC-UPQC for directs of load voltage and load current in adjoining parallel feeder has been proposed and contrasted with a customary MC-UPQC, the proposed control topology is able to do completely ensuring basic and touchy burdens against sudden evolving loads, voltage list/swells, and blame interference in two-feeder circulation frameworks. The execution of the SRF based MC-UPQC is tried under different unsettling influence conditions.

An Ultracapacitor Integrated Power Conditioner for Intermittency Smoothing and Improving Power Quality of Distribution Grid

ABSTRACT:

Penetration of various types of distributed energy resources (DERs) like solar, wind, and plug-in hybrid electric vehicles (PHEVs) onto the distribution grid is on the rise. There is a corresponding increase in power quality problems and intermittencies on the distribution grid. In order to reduce the intermittencies and improve the power quality of the distribution grid, an ultracapacitor (UCAP) integrated power conditioner is proposed in this paper. UCAP integration gives the power conditioner active power capability, which is useful in tackling the grid intermittencies and in improving the voltage sag and swell compensation. UCAPs have low energy density, high-power density, and fast charge/discharge rates, which are all ideal characteristics for meeting high-power low-energy events like grid intermittencies, sags/swells. In this paper, UCAP is integrated into dc-link of the power conditioner through a bidirectional dc–dc converter that helps in providing a stiff dc-link voltage. The integration helps in providing active/reactive power support, intermittency smoothing, and sag/swell compensation. Design and control of both the dc–ac inverters and the dc–dc converter are discussed. The simulation model of the overall system is developed and compared with the experimental hardware setup.

KEYWORDS:

  1. Active power filter (APF)
  2. Dc–dc converter
  3. D–q control
  4. Digital signal processor (DSP)
  5. Dynamic voltage restorer (DVR)
  6. Energy storage integration
  7. Sag/swell
  8. Ultracapacitors (UCAP)

 SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

 image001

Fig. 1. One-line diagram of power conditioner with UCAP energy storage.

EXPECTED SIMULATION RESULTS:

 image002

Fig. 2. (a) Source and load rms voltages Vsrms and VLrms during sag. (b) Source voltages Vsab (blue), Vsbc (red), and Vsca (green) during sag. (c) Injected voltages Vinj2a (blue), Vinj2b (red), and Vinj2c (green) during sag. (d) Load voltages VLab (blue), VLbc (red), and VLca (green) during sag.

image003

Fig. 3. (a) Currents and voltages of dc–dc converter. (b) Active and reactive

power of grid, load, and inverter during voltage sag.

 CONCLUSION:

In this paper, the concept of integrating UCAP-based rechargeable energy storage to a power conditioner system to improve the power quality of the distribution grid is presented. With this integration, the DVR portion of the power conditioner will be able to independently compensate voltage sags and swells and the APF portion of the power conditioner will be able to provide active/reactive power support and renewable intermittency smoothing to the distribution grid. UCAP integration through a bidirectional dc–dc converter at the dc-link of the power conditioner is proposed. The control strategy of the series inverter (DVR) is based on inphase compensation and the control strategy of the shunt inverter (APF) is based on id iq method. Designs of major components in the power stage of the bidirectional dc–dc converter are discussed. Average current mode control is used to regulate the output voltage of the dc–dc converter due to its inherently stable characteristic. A higher level integrated controller that takes decisions based on the system parameters provides inputs to the inverters and dc–dc converter controllers to carry out their control actions. The simulation of the integrated UCAP-PC system which consists of the UCAP, bidirectional dc–dc converter, and the series and shunt inverters is carried out using PSCAD. The simulation of the UCAP-PC system is carried out using PSCAD. Hardware experimental setup of the integrated system is presented and the ability to provide temporary voltage sag compensation and active/reactive power support and renewable intermittency smoothing to the distribution grid is tested. Results from simulation and experiment agree well with each other thereby verifying the concepts introduced in this paper. Similar UCAP based energy storages can be deployed in the future in a microgrid or a low-voltage distribution grid to respond to dynamic changes in the voltage profiles and power profiles on the distribution grid.

 REFERENCES:

[1] N. H. Woodley, L. Morgan, and A. Sundaram, “Experience with an inverter-based dynamic voltage restorer,” IEEE Trans. Power Del., vol. 14, no. 3, pp. 1181–1186, Jul. 1999.

[2] J. G. Nielsen, M. Newman, H. Nielsen, and F. Blaabjerg, “Control and testing of a dynamic voltage restorer (DVR) at medium voltage level,” IEEE Trans. Power Electron., vol. 19, no. 3, pp. 806–813, May 2004.

[3] V. Soares, P. Verdelho, and G. D. Marques, “An instantaneous active and reactive current component method for active filters,” IEEE Trans. Power Electron., vol. 15, no. 4, pp. 660–669, Jul. 2000.

[4] H. Akagi, E. H. Watanabe, and M. Aredes, Instantaneous Reactive Power Theory and Applications to Power Conditioning, 1st ed. Hoboken, NJ, USA: Wiley/IEEE Press, 2007.

[5] K. Sahay and B. Dwivedi, “Supercapacitors energy storage system for power quality improvement: An overview,” J. Energy Sources, vol. 10, no. 10, pp. 1–8, 2009.