Measurement and Modelling of Leakage Current Behaviour in ZnO Surge Arresters under Various Applied Voltage Amplitudes and Pollution Conditions

Latiff, Nurul Ain Abdul; Illias, Hazlee Azil; Bakar, Ab Halim Abu; Dabbak, Sameh Ziad Ahmad

doi:10.3390/en11040875

“…We notice that relation (5) offers a very good estimation compared to (7). The time evolution of the temperature, during the "after pulse" cooling process, for the same previous randomly chosen point, is shown in Fig.6.…”

Section: Resultsmentioning

confidence: 87%

Computer Aided Model for a Low Voltage Varistor with Increased Thermal Stability

Olariu¹,

Frigura-Iliasa²,

Balcu³

et al. 2018

EECSI

0

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Metal Oxide Varistors are a very common power electronic device, applied for efficient overvoltage protection at any voltage level. This piece of equipment has a high non-linear current response function of the applied voltage, and, it provides a relatively high heat absorption capacity in case of accidental overvoltage pulse (shock)s. The crossing response current is clearly activated by temperature of that device, and, by consequent, overheating could be disastrous. Actual researches must be carried out both for a new more performant material as well as for new technical solutions for the design of all equipment integrating them, by studying heat extraction and heat transfer inside a new complex varistor device. Our article proposes a totally new device, used basically for low voltage applications, having a supplementary metal mass added to the body of that varistor, shaped as small disk. It actions like a heat pump immediately after the voltage pulse (shock) and as additional radiators at the end of the heating process caused by a transitory overvoltage. A CAD solution combined with a finite element model, followed by some experimental results are also presented, for confirming the performance of that newly design. By placing additional metal alloy masses inside a new varistor structure it will have a higher heat pumping and dissipation capability, in order to reduce temperature stress and all aging effects.

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“…where f -Frequency (Hz); I-Rated current (A); W-Coil number (Turn); et-Every potential (V); H-Average reactance height of two coils (m); ΣD-Magnetic flux leakage area (m 2 ); ρ-Rockwell coefficient; K-Additional reactance coefficient, generally take 1. The SVG's output voltage is connected to the grid after being boosted by the transformer, which reduces the SVG's insulation voltage design difficulty [17,18], reduces the number of each phase power modules connected in series, and simplifies the design of the control system. In order to improve the reactive output current and meet the demand for large-capacity reactive power compensation In order to meet the requirements of the connection between SVG and power grid, the value of the transformer leakage reactance range is 8-13%.…”

Section: Svg Structurementioning

confidence: 99%

Low-Harmonic DC Ice-Melting Device Capable of Simultaneous Reactive Power Compensation

Lu

¹

,

Zhu

²

,

Li

³

et al. 2018

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As a result of the high efficiency of ice-melting and the small power supply capacity, DC ice-melting devices are widely used in relation to transmission lines in the power grid. However, it needs to consume reactive power when ice-melting, and voltage fluctuation of the substation may be caused when the demand for reactive power is large. It also generates a large number of 5th and 7th harmonics when ice-melting. In this paper, combined with the demand for ice-melting for transmission lines and the dynamic reactive power of substations, a low-harmonic DC ice-melting device capable of simultaneous reactive power compensation is studied. The function of ice-melting and reactive power compensation can be operated simultaneously and the rectifier's main harmonics can be eliminated. The simulation and experimental research on the device was carried out in the 500 kV Chuanshan substation. The actual ice melting was carried out on the 500 kV Chuansu I line and took only 68 min to melt the ice. The 500 kV bus voltage had no negative deviation, and the positive deviation decreased from +3.09% to +1.57% within 24 h of testing. The results prove the feasibility of the proposed DC ice-melting device in this paper.

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“…As previously explained, the most important issue concerning heat absorption capacity is to maintain the varistor inside the so-called "thermal stability" envelope, by carefully limiting its service temperature [7].…”

Section: Additional Metal Mass Principlementioning

confidence: 99%

Computer Aided Model for a Low Voltage Varistor with Increased Thermal Stability

Olariu¹,

Frigura-Iliasa²,

Balcu³

et al. 2018

EECSI

0

View full text Add to dashboard Cite

Metal Oxide Varistors are a very common power electronic device, applied for efficient overvoltage protection at any voltage level. This piece of equipment has a high non-linear current response function of the applied voltage, and, it provides a relatively high heat absorption capacity in case of accidental overvoltage pulse (shock)s. The crossing response current is clearly activated by temperature of that device, and, by consequent, overheating could be disastrous. Actual researches must be carried out both for a new more performant material as well as for new technical solutions for the design of all equipment integrating them, by studying heat extraction and heat transfer inside a new complex varistor device. Our article proposes a totally new device, used basically for low voltage applications, having a supplementary metal mass added to the body of that varistor, shaped as small disk. It actions like a heat pump immediately after the voltage pulse (shock) and as additional radiators at the end of the heating process caused by a transitory overvoltage. A CAD solution combined with a finite element model, followed by some experimental results are also presented, for confirming the performance of that newly design. By placing additional metal alloy masses inside a new varistor structure it will have a higher heat pumping and dissipation capability, in order to reduce temperature stress and all aging effects.

show abstract

Measurement and Modelling of Leakage Current Behaviour in ZnO Surge Arresters under Various Applied Voltage Amplitudes and Pollution Conditions

Cited by 37 publications

References 32 publications

Computer Aided Model for a Low Voltage Varistor with Increased Thermal Stability

Computer Aided Model for a Low Voltage Varistor with Increased Thermal Stability

Low-Harmonic DC Ice-Melting Device Capable of Simultaneous Reactive Power Compensation

Computer Aided Model for a Low Voltage Varistor with Increased Thermal Stability

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