Non-linear least-squares-based harmonic estimation algorithm for a shunt active power filter

Chudamani, R.; Vasudevan, Krishna; Ramalingam, C.S.

doi:10.1049/iet-pel:20080006

Cited by 29 publications

(25 citation statements)

References 8 publications

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“…But for IPQT method the %THD increase is by 3% in all 3 phases which in turn makes the total harmonic distortion percentage of the compensated supply current exceed the maximum permissible limit of 5% as prescribed in the IEEE standards. Thus the CB algorithm is able to maintain the %THD of the supply current within 5% even under conditions of unbalance in supply voltage which is not the case for IPQT algorithm as observed by other researchers [13]. The above set of results clearly indicate that the proposed CB based method performs equally good as IPQT method under steady state conditions , but provides better results under transient conditions.…”

Section: ) Unbalanced Supply Voltage Conditionsupporting

confidence: 52%

“…Under these sudden load changing condition it is observed that time taken to restabilize by the APF with CB method was much lesser (i.e.12ms) than that with IPQT method which took 22 ms for the same condition. The reason behind this is the use of low pass filters in the IPQT algorithm which introduces a delay in processing of the measured signals [13].This was validated by observing the change obtained in the DC voltage waveform across the capacitor connected in parallel to the APF, as shown in Fig.7 and Fig.8 respectively. In this testing condition the load type on the DC side of the 3 phase diode bridge rectifier is suddenly changed from resistivecapacitive type to resistive type.…”

Section: )mentioning

confidence: 90%

“…It eliminates the use of low pass filters which therefore limits the response time for CB method to 12 ms in contrast to IPQT method which delays for 22ms. Of course in [13] authors have shown even a lesser delay time of 7ms, but the algorithm used involves heavy computations which requires a high speed processor for practical implementation [7].…”

Section: ) Unbalanced Supply Voltage Conditionmentioning

confidence: 99%

“…But the results of the algorithm deteriorates in an unbalanced three phase system and frame transformation calculations in the algorithm increase the computation burden of the processor wherein it is implemented. Also, the use of low pass filters in the algorithm decreases the rate of execution of the algorithm [13]. Therefore to overcome these problems Synchronous Reference frame (SRF) [14]- [16] theory and other Phase Locked Loop (PLL) [17]- [18] based method have also been proposed.…”

Section: Introductionmentioning

confidence: 99%

“…As a result of this, methods based on Artificial Neural Network (ANN) [7], [19], adaptive learning [20]- [22], nonlinear least square based method [13], genetic algorithm [23], Kalman Filters [24] were subsequently proposed in the literature for the harmonic current extraction of APF's. However out of the above mentioned methods, ANN requires a lot of training data for reliable operation [13], the Kalman filtering method produces around 3 cycle delay for sudden load changes [13], the nonlinear least square approach involves heavy iterative computations [7]. The speed and accuracy of the adaptive learning based methods depends upon the learning rate of the weight update rule used [9] and all the other methods involves high amount of computations for the processor.…”

Section: Introductionmentioning

confidence: 99%

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A New Method of Harmonic Current Extraction for Shunt Active Power Filters

Ghosh¹,

Koley²,

Roy³

2017

IJERT

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Abstract:-Application of active power filters (APFs) towards the ever increasing problem of harmonic distortion in industrial power system, due to nonlinear loads, has become a reliable and flexible alternative. In this paper, a new method of harmonic current extraction based on charge balance principle, for shunt active power filter towards mitigation of harmonics and maintaining unity power factor both under steady state and transient operating conditions, is presented. This method involves simple mathematical calculations devoid of any iterative estimation process, so as to facilitate easy hardware implementation for industrial use. Finally simulation results for a comparative study between the proposed method and the popularly used Instantaneous PQ theory (IPQT) method is presented which reveals improved performance of the former with respect to performance, theoretical simplicity and required computation for improvement in power quality.

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Section: ) Unbalanced Supply Voltage Conditionsupporting

confidence: 52%

Section: )mentioning

confidence: 90%

Section: ) Unbalanced Supply Voltage Conditionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A New Method of Harmonic Current Extraction for Shunt Active Power Filters

Ghosh¹,

Koley²,

Roy³

2017

IJERT

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Implementation of EMD‐based control algorithm for a cascaded multilevel inverter–based shunt active filter

Dash

Panda

Lenka

2019

Int Trans Electr Energ Syst

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Summary This paper describes an empirical mode decomposition control algorithm to extract the fundamental component and set the reference for harmonic extraction in a cascaded multilevel inverter–based shunt active filter. The proposed technique is fully reliant on the data samples that are decomposed instantaneously and does not require any weighing factor. The fundamental component of load current is found by applying a novel empirical mode decomposition algorithm from the nonlinear load current samples. Spline interpolation is used to extract the intrinsic mode function. For online implementation, the maxima and minima points of load current are stored using a modified field programming gate array (FPGA)‐based circular buffer circuit. Finally, the proposed cascaded multilevel inverter–based shunt active filter is investigated both by simulation and hardware implementation. The results obtained validates the performance of the proposed control technique under balanced and unbalanced loading conditions.

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Tracking of power quality disturbances using sparse model–based extended Kalman filters

Sahoo

Subudhi

Mishra

2018

Adaptive Control & Signal

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Accurate estimation and tracking of power quality (PQ) disturbances requires efficient adaptive model-based techniques, which should have elegant structures to be applicable in practical systems. Though extended Kalman filter (EKF) has been used as a popular estimator to track the time-varying PQ events, the performance is limited due to higher-order nonlinearity exists in system dynamics.Moreover, the computational complexity and sensitivity to the measurement noise affect the estimation accuracy and error convergence properties. If the underlying sparse behavior of adaptive filters can be exploited through norm penalty, then significant improvement can be achieved in terms of convergence speed, stability, and steady state excess mean square error performance. In this paper, a modification to EKF is proposed by using sparse model to estimate PQ disturbances with better estimation accuracy and faster convergence speed.A thorough comparison is presented in terms of simulation results by using a family of existing algorithms like least mean square, recursive least square, and EKF. Adaptive estimation model incorporates real and complex state space representations to represent discrete time PQ disturbances. The convergence of the proposed sparse model-based filter is also mathematically proved considering the mean square error performance.

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Non-linear least-squares-based harmonic estimation algorithm for a shunt active power filter

Cited by 29 publications

References 8 publications

A New Method of Harmonic Current Extraction for Shunt Active Power Filters

A New Method of Harmonic Current Extraction for Shunt Active Power Filters

Implementation of EMD‐based control algorithm for a cascaded multilevel inverter–based shunt active filter

Tracking of power quality disturbances using sparse model–based extended Kalman filters

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