Extraction of Harmonics Using Composite Observers

Selvajyothi, K.; Janakiraman, P.A.

doi:10.1109/tpwrd.2007.911141

Cited by 51 publications

(43 citation statements)

References 14 publications

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“…The sampling period is also 100 s µ . For a frequency deviation due to the variation of operating motor speed by ±10%, the observer performance is still good [15]- [16]. Fig.…”

Section: Simulation Resultsmentioning

confidence: 91%

Extension of the Operating Speed for Vector-Controlled Induction Machine Drives in the Overmodulation Range

Nguyễn¹,

Lee²

2012

Journal of Power Electronics

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This paper proposes a novel current control scheme for vector-controlled induction machine (IM) drives in the overmodulation (OVM) range, with which the voltage utilization of the voltage-source inverter (VSI) can be maximized. In the OVM region, the original voltage reference is modified by changing its magnitude and angle, which causes the motor current to be distorted, resulting in a deterioration of the current control performance. To meet with this situation, the harmonic components in the feedback currents should be eliminated before being input to the PI current controllers. For this, a composite observer is applied to extract the fundamental and harmonic components from the distorted currents, which gives a good performance without a delay and the effect of a fundamental frequency variation. In addition, through a detailed analysis of the response of the PI current controllers in the OVM range, the effectiveness of using the composite observer is demonstrated. Simulation and experimental results for a 3-kW induction motor drive are shown to verify the validity of the proposed method.

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“…The sampling period is also 100 s µ . For a frequency deviation due to the variation of operating motor speed by ±10%, the observer performance is still good [15]- [16]. Fig.…”

Section: Simulation Resultsmentioning

confidence: 91%

Extension of the Operating Speed for Vector-Controlled Induction Machine Drives in the Overmodulation Range

Nguyễn¹,

Lee²

2012

Journal of Power Electronics

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“…A composite observer is used to extract the individual harmonic components from a periodic signal which is composed of the DC component, y 0 (t), and the fundamental and high-order harmonic components, y 1 (t), ..., y N (t), respectively, where N is the maximum number of harmonic components [16], [17]. For practical applications, the composite observer is usually designed in the discrete time domain, which can be easily implemented by a digital signal processor (DSP).…”

Section: A Discrete Composite Observermentioning

confidence: 99%

Control Strategy for Three-Phase Grid-Connected Converters under Unbalanced and Distorted Grid Voltages Using Composite Observers

Nguyễn¹,

Lee²

2013

Journal of Power Electronics

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This paper proposes a novel scheme for the current controller for the grid-side converter (GSC) of permanent-magnet synchronous generator (PMSG) wind turbines to eliminate the high-order harmonics in the grid currents under grid voltage disturbances. The voltage unbalance and harmonics in three-phase systems cause grid current distortions. In order to mitigate the input current distortions, multi-loop current controllers are applied, where the positive-sequence component is regulated by proportional-integral (PI) controllers, and the negative-sequence and high-order harmonic components are regulated by proportional-resonance (PR) controllers. For extracting the positive/negative-sequence and harmonic components of the grid voltages and currents without a phase delay or magnitude reduction, composite observers are applied, which give faster and more precise estimation results. In addition, an active damping method using PR controllers to damp the grid current component of the resonant frequency is employed to improve the operating stability of VSCs with inductor-capacitor-inductor (LCL) filters. The validity of the proposed method is verified by simulation and experimental results.

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“…The DSTATCOM performance is dependent on the control algorithm used to derive the reference current components. Several control schemes have been reported in the literature [12][13][14][15][16][17][18][19][20][21]. Genetic and fuzzy logic algorithms have been used to find the PI controller parameters of the DSTATCOM [12,13].…”

Section: Introductionmentioning

confidence: 99%

“…In such methods, the EPLL is used for harmonic and interharmonic estimation. A composite observer-based control algorithm is implemented in a 3-phase DSTATCOM for improving power quality, e.g., harmonic elimination, reactive power compensation, load balancing, and neutral current compensation in a 3-phase 4-wire distribution system [18][19][20]. In [21], a linear sinusoidal tracer control algorithm based on adaptive theory is used by a DSTATCOM for the extraction of fundamental components of load currents in 3-phase loads.…”

Section: Introductionmentioning

confidence: 99%

A multifunctional DSTATCOM for power quality improvement

Mahdianpoor¹,

Kiyoumarsi²,

Ataei³

et al. 2017

Turk J Elec Eng & Comp Sci

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Abstract:The distribution static compensator (DSTATCOM) is used for various purposes such as load balancing, harmonic rejection, and power factor correction (PFC) in power distribution networks. In unbalanced and polluted power systems, the classic definition of power factor cannot be used for PFC due to the existence of harmonics and negative sequence components in voltage and current waveforms. In this paper, PFC is performed using the IEEE power factor definition for harmonic and unbalanced environments. Moreover, the application of a proportional-resonant (PR) controller is proposed as an effective controller in the stationary frame for DSTATCOM performance improvement. The PR controller is used in the abc-frame for load balancing and is then compared theoretically and by simulation with the conventional PI controller, which has the main drawback of steady-state error when used in the stationary frame. To improve the DSTATCOM structure, an LCL harmonic filter is used as it is advantageous over the L/LC filter in terms of the size of the filter. The proposed DSTATCOM compensates for the disturbances in the source current imposed by nonlinear, unbalanced, and low power factor loads. Simulation results show the capability of the DSTATCOM including the proposed PR controller in improving the power quality of distribution systems.

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Extraction of Harmonics Using Composite Observers

Cited by 51 publications

References 14 publications

Extension of the Operating Speed for Vector-Controlled Induction Machine Drives in the Overmodulation Range

Extension of the Operating Speed for Vector-Controlled Induction Machine Drives in the Overmodulation Range

Control Strategy for Three-Phase Grid-Connected Converters under Unbalanced and Distorted Grid Voltages Using Composite Observers

A multifunctional DSTATCOM for power quality improvement

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