Capacitor Current / Capacitance / Reactor Rate
From reactive compensation, compute capacitor phase current, per-phase capacitance, and rated voltage, with series reactor rate and resonant order.
Key points
Capacitor Current / Capacitance / Reactor Rate: From reactive compensation, compute capacitor phase current, per-phase capacitance, and rated voltage, with series reactor rate and resonant order. Formula: Q_c = P·(tanφ₁ − tanφ₂) | C = Q_phase/(2πf·U_c²) | h = 1/√p. Enter parameters on the DD-CAT IDE online tool page to get results instantly, with a calculation-model diagram that updates with the inputs. Compensation follows P(tanφ₁−tanφ₂); capacitor output scales with voltage squared, so low voltage reduces compensation. In harmonic environments use series reactors: 7% avoids the 5th, 14% avoids the 3rd. Reactors raise capacitor terminal voltage, so select a higher capacitor rating.
Inputs
Q_c = P·(tanφ₁ − tanφ₂) | C = Q_phase/(2πf·U_c²) | h = 1/√pCalculation model (updates with parameters)
| Required compensation Q_c | 55.32 kvar | P·(tanφ₁−tanφ₂) |
| Per-phase compensation | 18.44 kvar | 三相均分 |
| Capacitor phase voltage U_c | 400 V | Δ 接承受线Voltage |
| Per-phase capacitance C | 366.9 µF | Q_相/(2πf·U_c²) |
| Capacitor line current I_c | 79.85 A | 选接触器、熔断器and导线用 |
| Series reactor rate p | 7 % | Resonant order h ≈ 3.8 |
| Suggested capacitor rated voltage | 430.1 V | Reactor会抬高Capacitance器端Voltage，不能按System voltage直接选 |
| Resonant order h | 3.78 次 | h = 1/√p |
Engineering notes
- Compensation follows P(tanφ₁−tanφ₂); capacitor output scales with voltage squared, so low voltage reduces compensation.
- In harmonic environments use series reactors: 7% avoids the 5th, 14% avoids the 3rd. Reactors raise capacitor terminal voltage, so select a higher capacitor rating.
- Capacitor banks need dedicated breakers / capacitor-switching contactors, fuses, and discharge resistors; do not use ordinary contactors for frequent switching.
FAQ
- What is Capacitor Current / Capacitance / Reactor Rate for?
- From reactive compensation, compute capacitor phase current, per-phase capacitance, and rated voltage, with series reactor rate and resonant order.
- What is the formula for Capacitor Current / Capacitance / Reactor Rate?
- Core formula: Q_c = P·(tanφ₁ − tanφ₂) | C = Q_phase/(2πf·U_c²) | h = 1/√p. The tool returns results instantly using this formula and the selected parameters.
- What engineering notes should I keep in mind when using Capacitor Current / Capacitance / Reactor Rate?
- Compensation follows P(tanφ₁−tanφ₂); capacitor output scales with voltage squared, so low voltage reduces compensation. In harmonic environments use series reactors: 7% avoids the 5th, 14% avoids the 3rd. Reactors raise capacitor terminal voltage, so select a higher capacitor rating. Capacitor banks need dedicated breakers / capacitor-switching contactors, fuses, and discharge resistors; do not use ordinary contactors for frequent switching.