Abstract
A technique for conducting online estimation of the intrinsic parameters of encapsulated three-phase harmonic filter capacitors is presented. The concept is based on firstly sampling the line voltage and current associated with the encapsulated capacitor, then formulating a capacitor current estimator to estimate the line currents with the sampled line voltages, and finally using the errors of the estimated and actual line currents to estimate the intrinsic parameters with a modified particle swarm optimization algorithm. A decoupled technique is formulated to estimate the unmeasurable circulating current in the encapsulated capacitor with the measured line voltages. A prototype for estimating the intrinsic parameters of an encapsulated three-phase capacitor in the harmonic filter for an adjustable speed drive for a 1.1kW motor-generator set has been built and evaluated. To facilitate the application of the proposed technology for Internet-of-Things (IoT) devices, the impact of different durations, sampling frequencies, and data lengths on the estimation accuracy is evaluated. The results are favorably compared with the theoretical predictions and the measurement results obtained on a calibrated network analyzer. In addition, the performance of the proposed technique is favorably compared with the Trust-Region-Reflective Least Squares Method.
Highlights
Power electronic systems (PES) are switching circuits in nature
The proposed m-particle swarm optimization (PSO) is an enhanced PSO that has random perturbation introduced for searching solution within the operation boundaries
With the Least Squares Method (LSM), the estimation error is more than 5% when the data length is one-fourth of the line cycle
Summary
Power electronic systems (PES) are switching circuits in nature. they consist of input filters for eliminating switching noises from getting into the supply, they still generate low-order input current harmonics in processing the energy converted from the input to the output, causing voltage and current distortion in the distribution network, and deteriorating the power quality of the power grid. Some variants are based on identifying the change of the resonant frequency in an LC filter to determine the variation of the capacitor [6] and the harmonic spectra in the filter current [11] Those methods have the following operational considerations: 1. A technique for conducting online estimation of the intrinsic parameters of encapsulated capacitors is presented It can only require a quarter line-cycle information of the measurable line voltage and associated capacitor currents. OPERATING PRINCIPLE Fig. 1 shows the equivalent circuit of an encapsulated three-phase harmonic filter capacitor It consists of three delta-connected capacitors Cab, Cbc, and Cca. The line currents are i1, i2, and i3 and the currents through the three capacitors are iab, ibc, and ica. Where iab,act , ibc,act , and ica,act are the actual currents of iab, ibc, and ica, respectively
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
