Induced Overvoltage Caused by Indirect Lightning Strikes in Large Photovoltaic Power Plants and Effective Attenuation Techniques

Abstract

Indirect Lightning Stroke (ILS) is considered an urgent issue on overall power systems due to its sudden dangerous occurrence. A grid-connected solar Photovoltaic (PV) power plant of 1MW was considered and analyzed using PSCAD/EMTDC software. The effect of grounding grid resistance (R g ) on the induced voltages caused by the indirect strokes was discussed. The Transient Grounding Potential Rise (TGPR) variation with R g was presented and discussed. Four different models were proposed and installed for the system under study, which includes a combination of the Externally Gapped Line Arrester (EGLA) with the Non-Gapped Line Arrester (NGLA). The results show that when the R g was reduced from 5 to 1 ohm, TGPR decreased by about 79.63%, whereas the peak value was reduced by about 91.3% nearby the striking position. Four models of EGLAs were proposed to reduce the induced transient overvoltage effectively. The four models showed a remarkable ability to reduce the backflow current (BFC) and, consequently, the induced overvoltage. The EGLA's type with the composite air gap reduced the TGPR by about 77.04 % and reduced the induced overvoltage nearby the striking position by about 51.3%.INDEX TERMS ILS, EGLA, NGLA, backflow current (BFC), PV, grounding grid design (GGD), composite insulator, discharge voltage.

Fast frequency response technology of photovoltaic power plant based on equivalent modelling

“…The AGC system receives the frequency and power signals of the grid-connected point of the photovoltaic power station, determines and calculates as required, and sends the power adjustment command to the photovoltaic inverter through the communication unit [15][16][17][18].…”

“…The AGC system receives the frequency and power signals of the grid‐connected point of the photovoltaic power station, determines and calculates as required, and sends the power adjustment command to the photovoltaic inverter through the communication unit [15–18]. Key technical points: The frequency measurement accuracy and frequency sampling period of the existing photovoltaic power station measurement and control devices are mostly unable to meet the fast frequency response requirements.…”

Support Vector Machine Parameters Optimization for 500 kV Long OHTL Fault Diagnosis

“…The ATPDraw model SM59/58 represents the station (Synchronous Generator (SG) =1250 MVA/500 kV) [32], [33].…”

External Multi-Gap Lightning Arrester Modeling Using the Integration Method

“…Some studies have shown an increase of reliability in distribution networks when using EGLAs in the primary of the transformers [21] as long as their protection level is low, i.e., with the lowest possible value of inception voltage, or combined with grounding systems of special characteristics, such as resonant grounding [22,23]. When grounding resistance values are greater than or equal to 5 Ohm, EGLAs perform better in terms of reducing backflow currents [24]. However, the use of these devices presents certain challenges in terms of stochastic operation of the gap discharge ignition and fast forward residual voltage pulses applied to the primary of the protected transformers.…”

“…Regardless of the protection measure used, a study of the effect of a lightning strike must always be performed in which, through modeling and simulation, the effectiveness of the protection scheme is evaluated to verify that the electrical stresses applied to the equipment during lightning events are maintained within their support margins [30,31]. For these studies, adequate modeling of all parts and components, such as line insulators, poles, grounding, transformers, and protection devices, among others, is required, since the reliability of the results depends directly on the quality and accuracy of the models used [24,32].…”