These metal parts are not connected with the shell or bus by the way of metal contact through charge. The image shows how PD emits energy. Am Stat. IEEJ Trans Power Energy 115:11361139. These sensors would be connected to the splice or termination by using the frequency spectrum of the discharges. In recent years, artificial intelligence has developed rapidly and has shown strong ability in many fields. This phenomenon is related to the movement of free particles in GIS. https://doi.org/10.1109/PES.2008.4596196. If we take a two-dimensional image I as input, we may also want to use a two-dimensional kernel K. Because the convolution operation is commutative, it can also be operated in the following way: The pooling layer function uses the overall statistical characteristics of the adjacent outputs in a location to replace the output of the network in that location. Finally, the experiment of the evaluation is presented to verify that the evaluation system can effectively and accurately perform GIS partial discharge monitoring and improve the reliability of power grid operation. PD occurs whenever there is a stressed region due to some impurity/cavity inside the insulation or when there is a protrusion outside it. It occurs because of the presence of cavities in solid or liquid insulation and the discharges are formed when the gas within the cavity is over-stressed. IEEE Trans Dielectr Electr Insul 7:124132. By Rudy Wodrich, VP of Engineering Services The number of PD pulses was counted from the raw data as preprocessing to calculate the feature value for the machine learning. Corona at sharp points in switchyards isnt usually detrimental. Never make contact on energized equipment with an ultrasound device! 9. The five types of partial discharge PRPD spectrogram are shown in Fig. Metal protrusion: There are some fixed defects in GIS, such as metal tip on the high voltage bus, metal tip on the metal shell, and metal protrusion on the pot insulator. Finally, the experiment of the evaluation is presented to verify that the evaluation system can effectively and accurately perform GIS partial discharge monitoring and improve the reliability of power grid operation. 2. Pattern recognition of partial discharge type is the recognition of phase resolved partial discharge (PRPD), PRPS, and other spectrograms in the final analysis, and the current image recognition technology has a very strong foundation, so it will have excellent performance when applied to partial discharge type recognition. According to the five partial discharge models mentioned above, the partial discharge experiments of typical insulation defect models in GIS are carried out, and the partial discharge characteristics are observed under AC high voltage. 4. Most of these characteristic parameters are defined according to experience. The model and physical design for free particle discharge are shown in Fig. It is significant to study GIS partial discharge and effectively classify the types of GIS partial discharge. Because the insulated epoxy board is opposite to the high-voltage electrode, and the lower part is opposite to the plane grounding electrode, it simulates GIS insulation defects of the floating conductor caused by loose parts and poor contact. J Phys D Appl Phys 35:2532. Download an information kittoday thats packed with information, including case studies, technical specifications, case studies and service information. On the other hand, the internal PD takes place inside the material and they are generally associated with defective manufacturing as they are caused due to cavities or holes inside the equipment that generate small gas breakdowns. The Trans Inst Electr Eng Jpn 105:269275. The activation function led to an increase in the nonlinear ability of the whole network. It is important to recognize and keep track of the partial discharges within electrical equipment from the moment of the arrival, as this is a progressive phenomenon that is necessary to check within established maintenance periods. It means that when the voltage phase reaches 90 or 270, partial discharge is more likely to occur. Considering that the amplitude of each discharge pattern is not the same, if the comparison is made directly, there may be a large error or even a probability error judgment, so we need to normalize all signals. The input graph data are convoluted through a multi-layer convolution layer, and the convolution operation is carried out through convolution kernel of the input data. What is the difference between control panel and MCC? The most practical ways revolve around detecting different radio frequency signals. please share your content to my mail id klionelr@gmail.com. The two ways are presented in our system as follows. The tf.train.AdamOptimizer (1 105).minimize function in tensorflow is used to get the minimum value of loss function. Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. https://doi.org/10.1109/TDEI.2002.1038663, Article Flukes innovative SoundSight technology converts ultrasound into a clear visual. The discharge capacity of the floating conductor is large, which will produce strong partial discharge and then lead to insulation breakdown. 2007 - 2023 Amperis Products S.L. https://doi.org/10.1023/A:1010933404324, Agoris DP, Hatziargyriou ND (1993) Approach to partial discharge development in closely coupled cavities embedded in solid dielectrics by the lumped capacitance model. The derivation of a multivariate composite function meets the chain rule, so the training of the neural network is also called gradient back propagation. Pollution will lead to electric field distortion along the surface and then lead to partial discharge, which will lead to breakdown in serious cases. We also use third-party cookies that help us analyze and understand how you use this website. When alternative materials to porcelain started to be introduced into switchgear and dry terminations started being widely introduced, some critical aspects of design and installation were not fully appreciated. https://doi.org/10.1007/s00202-021-01306-5, DOI: https://doi.org/10.1007/s00202-021-01306-5. The experiment results show that the generalization ability of the proposed algorithm is excellent, and the classification accuracy of our GIS partial discharge evaluation system is up to 94%. However, when entering a substation, you should always use your own senses. your institution, https://doi.org/10.1109/TDEI.2002.1038663, https://doi.org/10.1049/iet-gtd.2017.1012, https://doi.org/10.1541/ieejpes1990.121.9_1169, https://doi.org/10.1088/0022-3727/35/1/306, https://doi.org/10.1109/TDEI.2008.4712652, https://doi.org/10.1088/0022-3727/32/9/312, https://doi.org/10.15587/2312-8372.2017.102240, https://doi.org/10.1088/1742-6596/899/8/082001, https://doi.org/10.15587/2312-8372.2018.123309, https://doi.org/10.1541/ieejfms1972.105.269, https://doi.org/10.1109/UKRCON.2019.8879931, https://doi.org/10.1088/0022-3727/29/11/028, https://doi.org/10.1088/0022-3727/35/11/309, https://doi.org/10.1109/TDEI.2005.1430399, https://doi.org/10.1016/j.elstat.2017.03.004, https://doi.org/10.1541/ieejpes1990.111.7_706, https://doi.org/10.1541/ieejpes1990.115.10_1136, https://doi.org/10.1541/ieejeiss1987.116.7_734, https://doi.org/10.1109/ICACACT.2014.7223616, https://doi.org/10.1109/ACCESS.2020.2971319, https://doi.org/10.1109/ACCESS.2019.2962775, https://doi.org/10.1016/j.epsr.2019.106053, https://doi.org/10.1109/ICCSNT47585.2019.8962457, https://doi.org/10.1109/IEEECONF44664.2019.9048830, https://doi.org/10.1109/ICDAR.1995.598994, https://doi.org/10.1541/ieejfms1990.120.4_490, https://doi.org/10.1541/ieejfms1990.120.5_620. These PD are produced on the interface between two insulation mediums due to the permittivity change between them (materials with different relative permittivity). In the process of GIS component production, friction, environmental impact during installation, collision caused by component action in work, and failure to completely clean particles during GIS maintenance are all possible to produce metal particle adhesion. The most practical ways revolve around detecting different radio frequency signals. Anyone you share the following link with will be able to read this content: Sorry, a shareable link is not currently available for this article. Built-in capacitive sensors are also used to do the PD measurement. What are the differences between circuit breaker and fuse ? In: 2019 53rd Asilomar conference on signals, systems, and computers, pp 779783. Let Carlos (a consultant for a company developing solar PV system installations) tell you more about this topic. The circular hole with voids in the middle of the outer epoxy sheet simulates the defect of GIS voids. https://doi.org/10.1541/ieejpes1990.115.10_1136, Hara T, Hiraiwa N, Hirotsu K, Fukunage S (1996) Detection of partial discharges in power cables by neural network. If left unchecked, insulation failure can result not only in loss of supply to processes or customers but can also endanger staff. Some PRPD spectrogram cases of partial discharge: (a) metal protrusion, (b) voids discharge, (c) free particle discharge, (d) floating conductor, and (e) surface discharge. This cookie is set by GDPR Cookie Consent plugin. In the process of training, the batch_size is set as 128, and the model for the sample test is adopted after training. At present, deep learning usually uses GPU parallel computing to shorten the training time. The PD test would detect the insulation defects and also it can detect the insulation deterioration due to its operating conditions. https://doi.org/10.1109/IEEECONF44664.2019.9048830, Ho TK (1995) Random decision forests. All Rights Reserved.Legal Disclosures | In the second stage, the implementation stage feeds data to the corresponding variable space and then solves the problem. The RNN is a kind of recurrent neural network, which takes sequence data as input, recurses in the evolution direction of sequence, and all nodes are linked by chain.8,9 In addition, it has the advantage of memory and parameter sharing. Partial discharge often appears in GIS in the early stage of insulation deterioration. It is important that when the total data size N changes, the number of small batches m generally remains the same. Technology Audit and Production Reserves 39:3641. 2, the sample data signal is stored in the form of the PRPD spectrum in the sample database computer, which is converted from digital to analog through the sample data output system, and output in the form of UHF (ultra-high frequency) signals. Types of partial discharges A partial discharge (PD) is an electrical breakage phenomenon that is located in an insulating medium between two conductors that are at different potential. In this type piezoelectric transducer is used to convert the acoustic energy into electric energy, accelerometers, and acoustic emission sensors are the sensors that are used for acoustic detection. Most of the amplitude is below 0.1 V, and the discharge amplitude is low. https://doi.org/10.1109/TDEI.2017.006013, Lemke E (2012) A critical review of partial-discharge models. Technol Audit Prod Reserv 35:4449. Google Scholar, Okamoto T, Tanaka T (1985) Analysis of partial discharge characteristics by an equivalent circuit with fluctuating discharge time lag. The multi-layer is introduced in the hidden layer, and sigmoid or tanh function is applied to simulate the response of neurons to the excitation, so the neural network is optimized to overcome some previous shortcomings. IEEE Trans Dielectr Electr Insul 9:763808. Sulfur hexafluoride can be injected into the tank. During this process, there could be a hissing sound, violet glow, production of ozone . Any of these indicators can be a sign of severe PD and an unsafe environment. Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. The circuit schematic diagram is shown in Fig. Partial discharge is caused by dielectric stress caused by the presence of a high and non-homogeneous voltage in the insulation materials. E: Electrical Field Necessary cookies are absolutely essential for the website to function properly. This type of testing is done without disrupting the plant operation. This led to a spike in failure rates due to surface PD. For more information, see the section partial discharge detectors, Amperis is an ISO 9001 Certified Company. Enough data can better mine the inherent law of partial discharge in GIS and effectively improve the recognition rate of partial discharge types. In this figure Vc is the voltage in the cavity which is a fraction of the applied voltage Va. Analytical cookies are used to understand how visitors interact with the website. Detecting partial discharge in an electric power distribution facility with the Fluke ii910 Precision Acoustic Imager. The common source of the floating conductor is the shield electrode inside GIS. The charge will form a pulse current through the circuit, so that a pulse voltage signal proportional to the apparent discharge amount can be collected on the detection impedance. When the contact in GIS is loose, these metal parts are not connected with the two poles and become a point body separately, which will cause the discharge to the high voltage end or ground. A polyethylene sheet was used as the sample, and PD was generated by applying a high AC voltage to four different types of electrodes. Random gradient descent introduces randomness in every iteration. Electrical treeing originates from a defective point such as a small gas vacuum, a sharp electrode edge or a metallic particle, where the electric field is high. https://doi.org/10.1109/MEI.2011.5699446, Gouda OE, ElFarskoury AA, Elsinnary AR, Farag AA (2018) Investigating the effect of cavity size within medium-voltage power cable on partial discharge behaviour. The maximum pooling function gives the maximum value within the adjacent rectangular region. Partial discharge (PD) is a localized electrical discharge that only partially bridges the insulation between conductors and which may or may not occur adjacent to a conductor.. Das S, Purkait P (2008) -q-n pattern analysis for understanding partial discharge phenomena in narrow voids. Surface PD occurs across the surface of insulation. Capacitive couplers are used in rotating machines in order to detect the PD. 10, the following phenomena can be observed. Cond Monit Diagn 2018:16. Physical Signs of PD: Odors (ozone, burning, metallic), discolored lines or carbon tracks. The map pixel is 100 180. Of primary concern for most is safety. MathSciNet The optimization functions on neural networks generally have the following forms: where N represents the number of training samples and f(xi, yi) is the loss function of group i data. IEEJ Trans Fundam Mater 120:620630. The charge exchange will be generated by partial discharge. https://doi.org/10.1109/34.709601, Breiman L (2001) Random forests. It doesn't span the whole distance between two insulated electrodes - that's why it's called 'partial'. Non-intrusive instruments use the electromagnetic and ultrasonic emissions to detect problems. 10 fun and interactive questions. Partial discharge (PD) can occur in medium and high voltage switchgear. All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (. This is related to the well-known Corona Effect which is an electrical phenomena caused when the intensity on the conductor surface exceeds the breakdown strength of the surrounding gas and ends up creating the so-called corona sparks (PD) around the conductor (metal). Typical insulation defect setting on GIS entity equipment, B. https://doi.org/10.1007/s00202-021-01306-5, access via Practicality pictures of defects on the GIS entity equipment. This weak spot can grow and grow over time forming a tree within the insulation. This work was partially supported by the Japan Society for the Promotion of Science KAKENHI (Grant Number JP20H02140). Currently there are several methods of detecting partial discharge. https://doi.org/10.1109/TDEI.2017.006635, Trotsenko Y, Brzhezitsky V, Masluchenko I (2017) Circuit simulation of electrical breakdown in air using Kinds equal-area criterion. The following figure shows how the PD emits pulses in relation to the applied voltage. When there are external factors, such as interference, the metal parts will be loose, which will produce some floating conductor and then lead to repetitive partial discharge. Partial discharges produce damage that on the long term can end up in electrical failure, which is why it is convenient to establish preventive maintenance in order to consider replacement at proper time before the electrical failure takes place. PRPD spectrogram of partial discharge: (a) metal protrusion, (b) voids discharge, (c) free particle discharge, (d) floating conductor, and (e) surface discharge. According to the characteristics of each kind of insulation defect, the model building methods for five types of GIS partial discharge are given as follows. J Phys D Appl Phys 29:29222931. Alternately, Transient Earth Voltage (TEV) detection may be appropriate on some equipment. The stressed region is formed if there are sharp edges or protrusions around the conductor. In our paper, tensorflow will be selected as the training tool of neural networks. When the voltage at both ends of the bubble is higher than a certain value, partial discharge will occur. The general convolutional neural network consists of the following four layers: convolutional layer, pooling layer, fully connected layer, and activation function. However, the quantity of the data collected by the detection system is limited, so it is impossible to obtain a large amount of data. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. This type of testing is a reliable method to check for partial discharge. Further, when the field increases the breakdown capacity of this defect, it breaks down and discharges different forms of energy which result in partial discharge. IEEJ Trans Power Energy 111:706712. The practicality pictures of defects on the GIS entity equipment are shown in Fig. By watching your cables and switchgear, EA Technologys Astute HV Monitoring service can alert you to suspicious spikes and pinpoint which parts of your HV system should be investigated. The activation function layer is also called the nonlinear mapping layer. The convolutional neural network has the ability of representation learning, which can classify input information according to its hierarchical structure by shift invariant classification. Electrical treeing is one of the main degradation mechanisms in high-voltage polymeric insulation. The authors declare that there is no conflict of interest. How to help Electrical Engineering Community. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. https://doi.org/10.1109/MEI.2012.6340519, Hikita M, Yamada K, Nakamura A, Mizutani T, Oohasi A, Ieda M (1990) Measurements of partial discharges by computer and analysis of partial discharge distribution by the Monte Carlo method. Cavity-induced PD in solid dielectrics. The establishment of a highly accurate PD diagnostic technique has become necessary in recent years. If left unchecked, insulation failure can result not only in loss of supply to processes or customers but can also endanger staff. Since continuing education is encouraged by the executive management at your company, you arranged the training event. Partial discharge (PD) measurement is a diagnostic technique used for electrical insulating systems. Classification accuracy of GIS partial discharge in our evaluation system. First, the hardware of the evaluation system is introduced in detail. Partial discharge events are classified into two main groups: 1) External and surface partial discharges External and surface discharges include corona, glow and sliding discharges, pulse-free partial discharges, Trichel pulses to electrodes with sufficiently high Download an information kittoday thats packed with information, including case studies, technical specifications, case studies and service information. Google Scholar, Altman NS (1992) An introduction to kernel and nearest-neighbor nonparametric regression. You also have the option to opt-out of these cookies. Learn more about Institutional subscriptions, Bartnikas R (2002) Partial discharges their mechanism, detection and measurement. https://doi.org/10.2307/2685209, Article The major effect of a partial discharge is insulation breakdown, in medium and high voltage equipment the partial discharge is the indication of the insulation breakdown. As shown in Fig. The training weight matrix is back propagated according to the method of minimizing the error. Research Division of Product Reliability, Osaka Research Institute of Industrial Science and Technology, 7-1, Ayumino-2, Izumi-shi, Osaka, 5941157, Japan, You can also search for this author in Corona PD is what we often hear in outdoor switchyards, particularly when humid. Think you know PD? So in this test high voltage will be supplied to the insulation it is a withstand test, so high voltage will be supplied to the dielectric for fifteen minutes and the supply frequency will be 0.1HZ. Beyond personal safety, damaging partial discharge can cause: These issues can be avoided if the PD is detected early before substantial damage occurs. Some PRPD spectrogram cases of partial discharge are shown in Fig. Be Safe! Any of these indicators can be a sign of severe PD and an unsafe environment. It doesnt span the whole distance between two insulated electrodes thats why its called partial. Presence of bubbles in solid and liquid insulation. It is the key to obtain the partial discharge data for studying the algorithm of partial discharge type recognition in GIS.