Digital detection and fuzzy classification of partial discharge signals

-Reduction in pollution performance of polymeric insulators, aged due to water absorption stress and thermal stress, is a major threat to the reliable operation of power transmission and distribution system. Formation of partial discharges on the surface of wet polluted insulator plays a major role in determining the life time and pollution performance of outdoor polymeric insulators. However, reports on partial discharge characteristics of water absorption stress aged and thermal aged polymeric insulators are scanty. This paper discusses the pollution performance characteristics of accelerated aged polymeric insulators using the advanced ultra wide band PD signal measurement and analysis. Laboratory experiments on accelerated aged polymeric insulators were carried out as per IEC 60507 under AC voltage, at different humidity and contamination levels using NaCl as a contaminant. PRPD pattern and Time-Frequency map analysis of PD signals were carried out. From the results, it can be speculated that PD analysis is a well suited technique to understand the pollution performance of aged polymeric insulators.

Section: Separation Of Noise Signal From Pd Signalmentioning

confidence: 99%

Investigations of Accelerated Aged Polymeric Insulators Using Partial Discharge Signal Measurement and Analysis

Mekala¹,

Chandrasekar²,

Ravindran³

2015

“…At lightly polluted conditions (0.06 ESDD), the high frequency content ( 15-25 MHz) is also noticed in the frequency spectrum of the PD signal. With respect to increase in pollution level from 0.06 ESDD to 0.12 ESDD, the magnitude of high frequency content (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) significantly reduces and the dominant frequency content shifts towards 5-10 MHz. Energy content of the PD signal increases at long arcs and this will increase the surface local temperature of the thermal aged specimens, which will lead to faster erosion and degradation of the polymeric material.…”

Section: Time and Frequency Domain Analysis Of Pd Signalsmentioning

confidence: 99%

Flashover Prediction of Polymeric Insulators Using PD Signal Time-Frequency Analysis and BPA Neural Network Technique

Narayanan¹,

Karthik²,

Chandrasekar³

2014

-Flashover of power transmission line insulators is a major threat to the reliable operation of power system. This paper deals with the flashover prediction of polymeric insulators used in power transmission line applications using the novel condition monitoring technique developed by PD signal time-frequency map and neural network technique. Laboratory experiments on polymeric insulators were carried out as per IEC 60507 under AC voltage, at different humidity and contamination levels using NaCl as a contaminant. Partial discharge signals were acquired using advanced ultra wide band detection system. Salient features from the Time-Frequency map and PRPD pattern at different pollution levels were extracted. The flashover prediction of polymeric insulators was automated using artificial neural network (ANN) with back propagation algorithm (BPA). From the results, it can be speculated that PD signal feature extraction along with back propagation classification is a well suited technique to predict flashover of polymeric insulators.

“…The sensitivity ranges from 2 mV/div to 5V/div. PDBASE II also provides large number of digitized PD pulse waveforms and it is able to separate them according to the PD waveform shape [15][16][17][18]. The PD pulses were sent to a remote PC for further processing.…”

Section: Partial Discharge Testmentioning

confidence: 99%

“…In the case of PRPD pattern analysis peak discharge magnitude for each phase position window is plotted against the phase position. It investigates the PD patterns in relation to the 50Hz AC cycle [15][16][17][18].…”

Section: Prpd Pattern Analysismentioning

confidence: 99%

Investigations on PD Characteristics of Thermal aged Palm and Corn Oil for Power Transformer Insulation Applications

Senthilkumar¹,

Karthik²,

Chandrasekar³

2014

-Partial discharge (PD) detection plays a major role in the life time assessment of liquid insulation in power transformers. Many research works are being carried out to replace conventional mineral oil insulation in transformers by vegetable oils. It is necessary to understand the PD characteristics of vegetable oils before recommending them as an alternate for mineral oil. In this paper, the breakdown strength and PD characteristics of palm and corn oil were investigated in both unaged and thermally aged conditions. Laboratory experiments were performed as per IEC test procedures. PD signals were measured using wide band detection system. Phase resolved PD pattern of vegetable oils and mineral oil were compared. Effect of increase in voltage stress on the PD pattern of palm and corn oil were studied. Time and frequency domain analysis of PD pulses at needle-plane electrode configuration was carried out. Statistical analysis of PD pattern i.e. skewness and shape parameter variations with respect to applied thermal stress were also carried out. From the results, it is observed that palm and corn oils have better breakdown strength and PD characteristics even under long-term thermal stress and hence they can be used for power transformer applications.