Vietnam BESS (Circular 05/2025/TT-BCT Art. 44) — ride-through requirements

The LVRT, HVRT, FRT envelopes a grid-scale battery must meet under Vietnam BESS (Circular 05/2025/TT-BCT Art. 44) (Vietnam), digitized breakpoint by breakpoint and checked against the clause it came from.

By Sergey Syrvachev — Director of Product Engineering, grid-scale BESS · 10+ GWh delivered

Part of: the grid-code ride-through chart — compare this against 63 other standards in 42 countries.

What this is, and is not. A reading aid compiled from the clause cited below — not a compliance document. The primary text governs. Every value here was read from a current primary source.

Breakpoints

Times are seconds from the start of the disturbance. Voltage is per-unit of nominal; frequency in hertz. An LVRT curve is a lower boundary (stay connected while voltage is on or above it), an HVRT curve an upper boundary, and FRT gives the band between its High and Low boundaries.

Event Duty Breakpoints Status
low-voltage ride-through (LVRT) ride-through 0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.3 pu; 0.6s → 0.3 pu; 0.601s → 0.38 pu; 1.2s → 0.38 pu; 1.201s → 0.53 pu; 1.8s → 0.53 pu; 1.801s → 0.68 pu; 2.4s → 0.68 pu; 2.401s → 0.83 pu; 3s → 0.83 pu; 3.001s → 0.9 pu verified
high-voltage ride-through (HVRT) ride-through 0.001s → 1.2 pu; 0.5s → 1.2 pu; 0.501s → 1.15 pu; 3s → 1.15 pu; 3.001s → 1.1 pu verified
frequency ride-through (FRT) ride-through High: 0.1s → 52 Hz; 60s → 52 Hz; 60.001s → 51.5 Hz; 1800s → 51.5 Hz; 1800s → 51 Hz | Low: 0.1s → 47.5 Hz; 600s → 47.5 Hz; 600.001s → 48 Hz; 1800s → 48 Hz; 1800s → 49 Hz verified

Where these values come from

  • LVRT Circular 05/2025/TT-BCT dated 1 February 2025, Article 44 clause 3(a)-(c), as consolidated with Circular 46/2025/TT-BCT (in force 22 September 2025); identical envelope at Article 40 clause 6.
  • HVRT Circular 05/2025/TT-BCT dated 1 February 2025, Article 44 clause 3(c), 3(d) and 3(đ), as consolidated with Circular 46/2025/TT-BCT; identical envelope at Article 40 clause 6.
  • FRT Circular 05/2025/TT-BCT dated 1 February 2025, Article 44 clause 1, Table 17, as consolidated with Circular 46/2025/TT-BCT; identical table at Article 40 clause 2, Table 11.

Last checked against the source document on .

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