IEEE C62.22 および IEC 60099-4/5 に基づく MOV 避雷器選定。雷撃/開閉保護マージン (PM_L/PM_S)、TOV 能力検査、エネルギーダuty、分離距離補正、避雷器選択テーブルを計算。被保護機器端子の進行波 voltage を計算し、分離距離 adequacy を評価。跨分野 — あらゆる HV/MV システムに適用。ソーラーctx: PCS 変压器、変電所開閉器、集電系統用避雷器選定。
| MCOV (kV) | 定格 (kV) | LPL (kVp) | SPL (kVp) | PM_L (%) | PM_S (%) | TOV | エネルギー | 推奨 |
|---|
1. Lightning Protective Margin (PM_L)
PM_L = (BIL / LPL − 1) × 100% — IEEE C62.22 §5
Pass if PM_L ≥ 20% for self-restoring insulation.
PM_L = (BIL / LPL - 1) × 100 pm_l_pass = PM_L >= 20
2. Switching Protective Margin (PM_S)
PM_S = (BSL / SPL − 1) × 100% — IEEE C62.22 §5
Pass if PM_S ≥ 15% for switching impulse.
PM_S = (BSL / SPL - 1) × 100 pm_s_pass = PM_S >= 15
3. Separation Distance Voltage Correction
ΔV due to travel time: ΔV = 2 × τ × (rate of rise)
Effective level at equipment = datasheet level + ΔV
τ = d / v (one-way travel time in µs) ΔV_L = 2 × τ × (LPL / 1 µs) (lightning, 1 µs front) ΔV_S = 2 × τ × (SPL / 50 µs) (switching, 50 µs front) effectiveLPL = LPL + ΔV_L effectiveSPL = SPL + ΔV_S
4. Corrected Protective Margins at Equipment
Margins using effective protective levels at equipment terminals.
correctedPM_L = (BIL / effectiveLPL - 1) × 100 correctedPM_S = (BSL / effectiveSPL - 1) × 100
5. TOV Capability Check
IEEE C62.22 §6 TOV-withstand curve: duration → allowable factor × rated voltage.
E.g. 1 s → 1.8×, 10 s → 1.3×, 60 s → 1.2×, 3600 s → 1.0×.
allowableTOV = factor(tovDurationS) × arresterRatedVoltageKV tovCapabilityPass = tovExpectedKV <= allowableTOV
6. Energy Duty Check
Expected energy = energyDutyKJkV × MCOV (kJ)
Class thresholds: Distribution ≤ 1500 kJ, Intermediate ≤ 2500 kJ, Station ≤ 4000 kJ.
energyRequired_kJ = energyDutyKJkV × mcovKV energyDutyPass = energyRequired_kJ <= classEnergyThreshold
7. Arrester Class Selection (IEEE C62.22)
Distribution (Class A): system ≤ 52 kV AND LPL ≤ 100 kVp
Intermediate (Class B): 52 kV < system ≤ 345 kV OR LPL > 100 kVp
Station (Class C): system > 345 kV OR LPL > 150 kVp