G. Weller

Bio: G. Weller is an academic researcher from Alstom. The author has contributed to research in topics: Busbar & Wavelet transform. The author has an hindex of 1, co-authored 1 publications receiving 29 citations.

Application of wavelet transform in transient protection-case study: busbar protection

Abstract: This paper presents extensive studies of the application of wavelet transforms to detecting power system faults and describes a number of new protection principles and techniques based on the wavelet transform. These include a number of novel protection schemes for the protection of transmission lines, distribution feeders, generators and transformers. The significant advantages of these protection schemes are outlined in the paper. Finally the application of the proposed technique to busbar protection is presented to examine the feasibility of new protective algorithm.

High-speed differential busbar protection using wavelet-packet transform

Abstract: A novel wavelet-packet-transform- (WPT-) based differential busbar-protection technique is presented. The paper uses the wavelet-packet- transform (WPT) method to extract features from a fault-current signal. The WPT can decompose the fault signal into different frequency bands in the time domain. The differential signal is computed from the decomposed extracted signal. The WPT-based differential busbar-protection scheme solves several problems of current protective relays. The CT error and ratio-mismatch problems do not have any impact on the proposed WPT-based scheme. ATP simulations are used to test and validate the proposed technique for model-power-system faults.

An overview of wavelet transforms application in power systems

Abstract: Wavelet transform has received great attention in power community in the last years, because are better suited for the analysis of certain types of transient waveforms than the other transforms approach. This paper presents a descriptive overview of the wavelet transform applications in power systems. The main publications carried out in this field have been analyzed and classified by areas. A list of 116 references is also provided.

A Traveling-Wave-Based Amplitude Integral Busbar Protection Technique

Abstract: This paper proposes an extra high-speed busbar protection technique according to the propagation theory of traveling wave. When the fault occurs on the busbar, the detected initial traveling waves on all connected lines will come from their back, which are defined as positive direction traveling waves. While a fault occurs on any one of these lines, the detected initial traveling waves on all healthy lines are positive direction traveling waves; however, the traveling wave direction on the faulted line is negative. Within a short duration of postfault, a criterion discriminating fault direction can be established according to the amplitude integral relationships between the positive direction traveling wave and the negative direction traveling wave. Analyzing the detected traveling wave directions for all lines, a distributed busbar protection scheme can be constructed. To evaluate the proposed technique, a typical busbar model was built. Simulation results show that the proposed method can rapidly and reliably discriminate the internal faults from external faults, and the protection performances are immune to fault resistances, fault inception angles, fault types, and current-transformer saturation.

Computationally Efficient Wavelet-Transform-Based Digital Directional Protection for Busbars

Abstract: This paper proposes a novel wavelet-transform-based directional algorithm for busbar protection. The algorithm decomposes the current and voltage signals into their first-level details, which consist of frequencies in 500- to 1000-Hz bandwidth, for generating directional signals. A high level of computational efficiency is achieved compared to the other wavelet-transform-based algorithms proposed, since only the high-frequency details at the first level are employed in this algorithm. The validity of this method was exhaustively tested by simulating various types of faults on a substation modeled in the alternative transients program/electromagnetic transients program. The algorithm correctly discriminated between bus faults, various types of external faults, and transformer energization even in the presence of current-transformer saturation. This paper also provides the design details of the algorithm using field-programmable gate array technology.

A Novel Busbar Protection Method Based on Polarity Comparison of Superimposed Current

Abstract: This paper proposes a novel busbar protection method based on the polarity comparison of superimposed current. Analysis shows that all lines connected to the faulted busbar have the same polarities for the superimposed currents in case of an internal fault to busbar; but for a fault occurring on any one of these lines, the polarity on the faulted line is opposite of those on healthy lines. According to this important characteristic, the busbar protection criterion can be established. To improve the reliability of the busbar protection method, waveforms of superimposed currents are integrated within a short time after the fault. Moreover, a new phase-mode transformation matrix is proposed to realize that single aerial modulus can reflect all fault types. A real 500-kV substation busbar model was built in PSCAD to evaluate the performance of busbar protection. Simulation results demonstrate that the proposed protection method has good adaptability, fast operation speed, and high reliability. In addition, its performance is rarely influenced by the fault initial conditions, series compensation, and CT saturation, etc.