South Africa (NRS 097 / RPP) — ride-through requirements

The LVRT, HVRT, FRT envelopes a grid-scale battery must meet under South Africa (NRS 097 / RPP) (South Africa), 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 → 0.053 pu; 0.381s → 0.159 pu; 0.613s → 0.266 pu; 0.844s → 0.372 pu; 1.075s → 0.478 pu; 1.306s → 0.584 pu; 1.538s → 0.691 pu; 1.769s → 0.797 pu; 2s → 0.85 pu; 20s → 0.85 pu; 20.001s → 0.9 pu verified
high-voltage ride-through (HVRT) ride-through 0.001s → 1.2 pu; 2s → 1.2 pu; 2.001s → 1.1 pu verified
frequency ride-through (FRT) ride-through High: 0.2s → 52 Hz; 4s → 52 Hz; 4.001s → 51.5 Hz; 60s → 51.5 Hz; 60.001s → 51 Hz | Low: 0.2s → 47 Hz; 6s → 47 Hz; 6.001s → 47.5 Hz; 10s → 47.5 Hz; 10.001s → 48 Hz; 60s → 48 Hz; 60.001s → 49 Hz verified

Where these values come from

  • LVRT Grid Connection Code for Renewable Power Plants (RPPs) connected to the Electricity Transmission or Distribution System in South Africa, Version 3.1, January 2022 - clause 5.2.1(b)(3) 'withstand voltage drops to zero ... for a minimum period of 0.150 seconds' and Figure 4 'Voltage Ride through Capability for the RPPs of Category A3, B and C utilising non-synchronous machines' (time axis breakpoints 0.0 / 0.15 / 2.0 / 4.0 / 20.0 s; 85% level marked).
  • HVRT Grid Connection Code for RPPs in South Africa, Version 3.1, January 2022, clause 5.2.1(b)(4) and Figure 4 Area D (p.16); Umax from Table 1 (p.12).
  • FRT SA RPP Grid Code v3.1 (Jan 2022), clause 5.1(5) 'When the frequency on the NIPS is higher than 51.5 Hz for longer than 4 seconds, the RPP shall be disconnected' and Figure 2 'Minimum frequency operating range of a RPP (during a system frequency disturbance)' - upper boundary steps at 4 s (52 -> 51.5) and 60 s (51.5 -> 51.0); continuous range 49.0-51.0 Hz.

Last checked against the source document on .

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