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The model testing/simulations. Yasuhiro Honma. Technical Session on Home Networks Geneva , 29/04/2011. Outline. Mechanism of internal ports lightning surge Experiment and Simulation model Relation between AC mains lightning surge current and induced Internal port surge voltage/current
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The model testing/simulations Yasuhiro Honma Technical Session on Home Networks Geneva, 29/04/2011
Outline • Mechanism of internal ports lightning surge • Experiment and Simulation model • Relation between AC mains lightning surge current and induced Internal port surge voltage/current • Occurrence probability of AC mains surge current • Estimation for relation between Failure rate and test levels • Conclusion Technical Session - Home Networks - Geneva
Mechanism of internal port lightning surge for ONT/HGW Even fiber optic ONT/HGW equipment, if telecom. equipment is connected to the port which uses AC mains power, the surge voltage is generated during the internal ports. Case 2: Damage occurred between two internal ports of telecom equipment Damage: Telecom. Equip 1 (FAX), Home Gate Way & Telecom. equip 2 (PC) Route: AC mains(1) – TE1 -- HGW – TE2 – SPD – Local PE
Overvoltage measured in experimental house model Arrangement VPhase IEnt IPhase The relation ship between IEnt (current flow on entrance point) and Vphase/Iphase (Induced voltage and current) was examined experimentally
Spice model To investigate the effect of wire length, amplitude of entrance point current and so on, the results were compared between the SPICE simulation and experiment IEnt Table 1 Simulated parameters VPhase IPhase Technical Session - Home Networks - Geneva
Overvoltage measured in experimental house model Visuals Technical Session - Home Networks - Geneva
Results (1) waveformsExperiment and Simulation IEnt IPhase VPhase A VPhase VPhase B IEnt Technical Session - Home Networks - Geneva
Results (2) Peak valuesRelation between IEnt and Vphase , Iphase 7.5kA ⇒5kV Iphase Current [A] Vphase Voltage [kV] IEnt [kA] IEnt [kA] Figure 1 Relation between IEnt and Vphase Technical Session - Home Networks - Geneva
Observed lightning current on AC mains port Measurement period: 3 months. Frequency of currents >1 kA = 0.0009 per thunderstorm day. Frequency of currents >3 kA = 0.00015 per thunderstorm day. Cumulative occurrence frequency [times/thunder storm day] Lightning current peak value [A] Figure 2 Relation between lightning current peak value and occurrence frequency J.Kato T.Tominaga et.al, “Measurement results of Lighting surge current on ac mains line connected to access network equipment” EMC’04/Sendai Technical Session - Home Networks - Geneva
Calculation between Failure rate and Internal ports voltage (1) Estimation for occurrence probability of IEnt Assuming the Failure rate RFA[%] and the thunderstorm days per year DTS [Day/year] , The Occurrence Probability of IEnt is obtained by following equation , From the occurrence probability of IEnt, the maximum current flow on entrance point IEnt is obtained by Figure 2 (2) Estimation for Internal ports voltage of Vphase From the expected current flow of IEnt, the expected internal voltage VPhase is obtained by Figure 1 Technical Session - Home Networks - Geneva
Calculated results;Failure rate and Internal port voltage On average 20 thunderstorm days per year 15 million users of optical network equipment in Japan. If the failure rate assumes 0.05 %, the 7500 failures per year will occur. Technical Session - Home Networks - Geneva
Consideration on AC mains distribution system We reported that the lightning overvoltage between the internal ports of telecommunications equipment that used an optical line occurred due to lightning surges from the electric power line in the TT system (Japanese). We also evaluated the lightning overvoltage generated at the internal telecommunication ports for various system earthings. See TD 562:Evaluation of lightning overvoltage at internal telecommunication ports for various system earthings Fig. 14/TD 562 TN-C-S system (case 4) The internal ports voltage may occur. Technical Session - Home Networks - Geneva
Overvoltage measured in experimental house model Arrangement VPhase IEnt IPhase The relation ship between IEnt (current flow on entrance point) and Vphase/Iphase (Induced voltage and current) was examined experimentally
Conclusion • Introduced the mechanism of lightning over-voltage applied between the internal ports for ONT/HGW. • Derived a relationship between the AC mains lightning current and internal ports voltage/current from the experiment and simulation. • Assuming the failure rate is 0.05%, and thunderstorm days is 30 day, the internal ports voltages was estimated, the calculated voltage was almost 10 kV. Technical Session - Home Networks - Geneva