Transformer A loading
80%
Kalkulator Operasi Paralel Transformator
Verifikasi apakah dua transformator dapat beroperasi paralel (kelompok vektor, rasio, impedansi, rasio kapasitas) dan lihat bagaimana beban terbagi di antara keduanya dalam proporsi terbalik terhadap impedansi hubung singkatnya.
Hasil
Masukkan beban Anda → dapatkan desain lengkap & BOM dalam hitungan detik
Contoh keluaranParallel load sharing
798 / 502 kVA
1300 kVA total across 1000 kVA (uk 6%) + 630 kVA (uk 6%) · Feasible for parallel operation ✓
Transformer B loading
80%
Combined capacity
1630 kVA
Overall load factor
80%
Parallel-operation conditions (IEC 60076)
| Condition | Value | Verdict |
|---|---|---|
| Same vector group | Matched (e.g. Dyn11 = Dyn11) | PASS ✓ |
| Same voltage ratio | 0% difference (≤ 0.5% recommended) | PASS ✓ |
| Impedance within tolerance | |uk_A − uk_B| = 0.0% of mean (≤ 10%) | PASS ✓ |
| Capacity ratio ≤ 3:1 | 1.59 : 1 | PASS ✓ |
Load sharing calculation
| Weight A | Sa ÷ uk_A = 1000 ÷ 6 = 166.7 |
| Weight B | Sb ÷ uk_B = 630 ÷ 6 = 105.0 |
| Load A | 1300 × 166.7 ÷ 271.7 = 798 kVA (80%) |
| Load B | 1300 × 105.0 ÷ 271.7 = 502 kVA (80%) |
Conclusion
The two units can operate in parallel; load splits in inverse proportion to their short-circuit impedance.
Bill of materials
| Equipment | Spec | Qty | Subtotal |
|---|---|---|---|
| Transformer A (oil-immersed S11) | 1000 kVA · uk 6% | 1 | POA |
| Transformer B (oil-immersed S11) | 630 kVA · uk 6% | 1 | POA |
| Total equipment | POA |
Untuk insinyur sistem tenaga dan pabrik yang menghitung ukuran bank transformator paralel untuk redundansi, ekspansi kapasitas, atau keandalan N−1.
Gunakan kalkulator
Contoh perhitungan
Contoh referensi yang telah dihitung sebelumnya (dapat dirayapi — tidak memerlukan JavaScript). Masukkan parameter Anda sendiri di atas untuk hasil langsung.
Contoh 1 — 1000 kVA + 630 kVA, impedansi 6% yang cocok
Parallel load sharing
798 / 502 kVA
1300 kVA total across 1000 kVA (uk 6%) + 630 kVA (uk 6%) · Feasible for parallel operation ✓
Transformer A loading
80%
Transformer B loading
80%
Combined capacity
1630 kVA
Overall load factor
80%
Parallel-operation conditions (IEC 60076)
| Condition | Value | Verdict |
|---|---|---|
| Same vector group | Matched (e.g. Dyn11 = Dyn11) | PASS ✓ |
| Same voltage ratio | 0% difference (≤ 0.5% recommended) | PASS ✓ |
| Impedance within tolerance | |uk_A − uk_B| = 0.0% of mean (≤ 10%) | PASS ✓ |
| Capacity ratio ≤ 3:1 | 1.59 : 1 | PASS ✓ |
Load sharing calculation
| Weight A | Sa ÷ uk_A = 1000 ÷ 6 = 166.7 |
| Weight B | Sb ÷ uk_B = 630 ÷ 6 = 105.0 |
| Load A | 1300 × 166.7 ÷ 271.7 = 798 kVA (80%) |
| Load B | 1300 × 105.0 ÷ 271.7 = 502 kVA (80%) |
Conclusion
The two units can operate in parallel; load splits in inverse proportion to their short-circuit impedance.
Bill of materials
| Equipment | Spec | Qty | Subtotal |
|---|---|---|---|
| Transformer A (oil-immersed S11) | 1000 kVA · uk 6% | 1 | POA |
| Transformer B (oil-immersed S11) | 630 kVA · uk 6% | 1 | POA |
| Total equipment | POA |
Contoh 2 — impedansi dan rasio yang tidak cocok
Parallel load sharing
883 / 417 kVA
1300 kVA total across 1000 kVA (uk 6%) + 630 kVA (uk 8%) · Not recommended — check conditions below ✗
Transformer A loading
88%
Transformer B loading
66%
Combined capacity
1630 kVA
Overall load factor
80%
Parallel-operation conditions (IEC 60076)
| Condition | Value | Verdict |
|---|---|---|
| Same vector group | Matched (e.g. Dyn11 = Dyn11) | PASS ✓ |
| Same voltage ratio | 1.5% difference (≤ 0.5% recommended) | FAIL ✗ |
| Impedance within tolerance | |uk_A − uk_B| = 28.6% of mean (≤ 10%) | FAIL ✗ |
| Capacity ratio ≤ 3:1 | 1.59 : 1 | PASS ✓ |
Load sharing calculation
| Weight A | Sa ÷ uk_A = 1000 ÷ 6 = 166.7 |
| Weight B | Sb ÷ uk_B = 630 ÷ 8 = 78.8 |
| Load A | 1300 × 166.7 ÷ 245.4 = 883 kVA (88%) |
| Load B | 1300 × 78.8 ÷ 245.4 = 417 kVA (66%) |
Circulating current
A 1.5% no-load ratio difference drives a circulating current of ≈ 80 kVA between the two units (adds to the load, does not supply the load).
Bill of materials
| Equipment | Spec | Qty | Subtotal |
|---|---|---|---|
| Transformer A (oil-immersed S11) | 1000 kVA · uk 6% | 1 | POA |
| Transformer B (oil-immersed S11) | 630 kVA · uk 8% | 1 | POA |
| Total equipment | POA |
Cara perhitungannya
- · Bobot pembagian beban: w = S_nom ÷ uk untuk setiap unit.
- · Beban unit A: S_A = S × w_A ÷ (w_A + w_B); unit B juga demikian.
- · Pembebanan: S_A ÷ S_nom,A (harus tetap ≤ 100%).
- · Kondisi paralel: kelompok vektor sama, rasio tegangan sama (≤0,5%), impedansi dalam ±10% satu sama lain, rasio kapasitas ≤ 3:1.
- · Arus sirkulasi (ketidaksesuaian rasio): I_c ≈ ΔU ÷ (Z_A + Z_B) dalam per-unit.
Standar yang dirujuk
| Standard | Scope |
|---|---|
| IEC 60076-1 | Transformator daya — persyaratan umum |
| IEC 60076-8 | Transformator daya — panduan aplikasi |
| IEEE C57.12.00 | Standar persyaratan umum untuk transformator distribusi dan daya terendam cairan |
Pertanyaan yang sering diajukan
What conditions must transformers meet to run in parallel?
Per IEC 60076, parallel transformers must match: voltage ratio (within ~0.5%), Vector Group, impedance voltage uk (within ~10%), and preferably power rating ratio under 3:1. Mismatched vector groups cause circulating current and severe overheating. The calculator checks these conditions and reports pass/fail.
How is load shared between parallel transformers?
Load shares inversely with impedance: the Transformer with lower uk carries more load. Two transformers of equal rating with uk 6% and 4.5% split load in the ratio 4.5:6, so the 4.5% unit carries 57%. The calculator computes the load share by impedance and flags overloading.
Why run transformers in parallel?
Parallel operation provides redundancy (one can be taken out for maintenance without outage), allows capacity to be added incrementally, and can improve efficiency at light load by running only one unit. The trade-off is higher fault level at the bus. The calculator models the parallel arrangement and its Fault Current.
What is circulating current between parallel transformers?
Circulating current flows when parallel transformers have unequal voltage ratios or different vector groups, even with no load, causing extra losses and heating. A 1% ratio mismatch can drive 5-10% circulating current. IEC 60076 limits the ratio difference to ~0.5%. The calculator checks for this.
What fault level results from paralleling transformers?
Paralleling transformers roughly sums their short-circuit contributions. Two 1000 kVA, 6% uk transformers give ~48 kA at the LV bus versus ~24 kA for one, so the switchgear must be uprated. The calculator computes the combined fault level so you can check panel ratings.
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