Does South Africa (NRS 097 / RPP) require ride-through, or only that the plant does not trip?

Ride-through, for the envelopes on this page — that is what each of them is. It is not everything South Africa (NRS 097 / RPP) contains: the clauses quoted under the charts also address when the plant may or must trip. The requirement sentence under each chart says which side of the curve is the compliant one.

Are the numbers on this page taken from South Africa (NRS 097 / RPP) itself?

Every breakpoint is read from the code, and where a point was taken off a published figure rather than stated in the clause, the section under that chart says so — on this page that includes an envelope that stops where its published chart stops. The clause each curve came from is quoted under it.

Which events are charted for South Africa (NRS 097 / RPP)?

South Africa (NRS 097 / RPP) is charted here with 3 envelopes — low-voltage ride-through, high-voltage ride-through, frequency ride-through (LVRT, HVRT, FRT).

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

Low-voltage ride-through, High-voltage ride-through, Frequency ride-through for South Africa. Every breakpoint below is read from the code itself, and where a point was taken off a published figure rather than stated in the clause, the section under that chart says so — an envelope that stops where its published chart stops.

3Envelopes

LVRT · HVRT · FRTEvents

Transmission & distribution Connection level

LVRT

What is the low-voltage ride-through envelope for South Africa (NRS 097 / RPP)?

The plant must ride through for any voltage that stays on or above this envelope. The envelope holds 0 pu from t = 0 to 150 ms; then ramps linearly from 0 pu at 150 ms to 0.85 pu at 2 s; then 0.85 pu from 2 s to 20 s; then 0.9 pu from 20 s, plotted to 60 s.

The clause states this boundary as a line; intermediate points are interpolated between its stated vertices. The envelope stops where the published chart stops; the code states no end time.

Applies to RPP categories A3/B/C on transmission or distribution

Low-voltage ride-through envelope for South Africa (NRS 097 / RPP). Time runs on a logarithmic axis, so the ramp — a straight line in real time — only looks curved here. Scroll the chart sideways for the rest of the time axis →

Low-voltage ride-through breakpoints for South Africa (NRS 097 / RPP)
From	To	Voltage	Between the points
0	150 ms	0 pu	Held flat
150 ms	2 s	0 → 0.85 pu	Ramps linearly
2 s	20 s	0.85 pu	Held flat
20 s	plotted to 60 s	0.9 pu	Held flat

The clause this came from

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). The code defines a linear recovery ramp; the vertices are read from the clause and the chart draws the segment between them.

HVRT

What is the high-voltage ride-through envelope for South Africa (NRS 097 / RPP)?

The plant must ride through for any voltage that stays on or below this envelope. The envelope holds 1.2 pu from t = 0 to 2 s; then 1.1 pu from 2 s onward — the last band the envelope defines, with no stated end time.

Every breakpoint is stated in the clause cited below.

Applies to RPP categories A3/B/C on transmission or distribution

High-voltage ride-through envelope for South Africa (NRS 097 / RPP). Time runs on a logarithmic axis. Scroll the chart sideways for the rest of the time axis →

High-voltage ride-through breakpoints for South Africa (NRS 097 / RPP)
From	To	Voltage	Between the points
0	2 s	1.2 pu	Held flat
2 s	no stated end	1.1 pu	Held flat

The clause this came from

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

What is the frequency ride-through envelope for South Africa (NRS 097 / RPP)?

The plant must ride through between the upper and lower bands. The upper (over-frequency) band holds 52 Hz from t = 0 to 4 s; then 51.5 Hz from 4 s to 60 s; then 51 Hz from 60 s onward — the last band the envelope defines, with no stated end time. The lower (under-frequency) band holds 47 Hz from t = 0 to 6 s; then 47.5 Hz from 6 s to 10 s; then 48 Hz from 10 s to 60 s; then 49 Hz from 60 s onward — the last band the envelope defines, with no stated end time.

The last band has no stated end time. The clause below states a continuous region — highlighted; check which band it covers, because it is not always the last one.

Applies to RPP categories A3/B/C on transmission or distribution

Frequency ride-through envelope for South Africa (NRS 097 / RPP). Time runs on a logarithmic axis. Scroll the chart sideways for the rest of the time axis →

Upper limit

Frequency ride-through breakpoints for South Africa (NRS 097 / RPP) — Upper limit
From	To	Frequency	Between the points
0	4 s	52 Hz	Held flat
4 s	60 s	51.5 Hz	Held flat
60 s	no stated end	51 Hz	Held flat

Lower limit

Frequency ride-through breakpoints for South Africa (NRS 097 / RPP) — Lower limit
From	To	Frequency	Between the points
0	6 s	47 Hz	Held flat
6 s	10 s	47.5 Hz	Held flat
10 s	60 s	48 Hz	Held flat
60 s	no stated end	49 Hz	Held flat

The clause this came from

SA RPP Grid Code v3.1 (Jan 2022), clause 5.1(4) (RPP shall be capable of operating for the minimum operating range illustrated in Figures 1 and 2), 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 from the grid' and 5.1(6) 'When the frequency on the NIPS is less than 47.0 Hz for longer than 200ms, the RPP may be disconnected'; Figure 2 'Minimum frequency operating range of a RPP (during a system frequency disturbance)' (p.13) — upper boundary steps at 4 s (52 -> 51.5) and 60 s (51.5 -> 51.0); lower boundary steps at 200 ms (-> 47), 6 s (47 -> 47.5), 10 s (47.5 -> 48) and 60 s (48 -> 49); continuous range 49.0-51.0 Hz.

Beyond ride-through

Operating requirements beyond the envelopes.

The envelopes above are what South Africa (NRS 097 / RPP) demands during a disturbance. The rows below are the same regime’s operating and fault-response requirements — reactive capability, frequency response, continuous operating range, ramp rate, RoCoF withstand and fault-current injection — each researched from the document its own row cites, separately from the plotted corpus. Every row carries its clause and a verbatim quote, so you can check it the same way. A row marked secondary source was read from an authoritative summary, not the standard itself, and is labelled so it cannot pass as clause-stated text.

Supplementary operating requirements for South Africa (NRS 097 / RPP)
Requirement	What the code states	Clause
Category C reactive envelope at POC (PF 0.95 at nominal voltage) Reactive capability	Rectangular Q envelope from 5% to 100% of Pn: at nominal POC voltage Qmin/Qmax correspond to cos phi 0.95 under-/over-excited (Q/Pn = -0.330 to +0.330 per Figures 10b/11); Qmin and Qmax are voltage-dependent (Figure 11 maps Q/Pn 0.228/0.330/0.410 to cos phi 0.975/0.950/0.925 across Umin-Un-Umax); below 5% Pn no capability requirement, only a Q tolerance band of +/-5% of rated power Binds RPPs of Category C (rated power >= 20 MVA, transmission- or distribution-connected), measured at the Point of Connection (POC); control mode (V, PF or Q) and operating point agreed with the NSP. Read from the sseg.org.za public reprint of the identical Rev 3.1 document; the issuer copy at nersa.org.za (…/files/files/2022/01/SAGC-Requirements-for-Renewable-Power-Plants-Rev-3.1.pdf) is the primary locator but returned HTTP 403 to automated access when checked (Aug 2026).	Section 7.3(2)-(4) secondary source
The clause this row cites Section 7.3(2)-(4) — “ When operating between 5% and 100% of rated power Pn (MW) the RPP of category C shall have the capability of varying reactive power (Mvar) support at the POC within the reactive power capability ranges as defined by Figure 10a, where Qmin and Qmax are voltage dependent as defined by Figure 11. (3) At nominal voltage, the required RPP reactive power capability (measured at the POC) shall be as shown in Figure 10b. (4) When operating below 5% of rated power Pn (MW), there is no reactive power capability requirement, however the RPP can only operate within the reactive power tolerance range not exceeding +-5% of rated power; that is within Area A,B,C and D in Figure 10b. ” (Grid Connection Code for Renewable Power Plants (RPPs) Connected to the Electricity Transmission System (TS) or the Distribution System (DS) in South Africa, accessed 2026-08-10)
Category B reactive envelope at POC (PF 0.975 at nominal voltage) Reactive capability	Rectangular Q envelope from 5% to 100% of Pn: at nominal POC voltage the required capability corresponds to cos phi 0.975 under-/over-excited (Q/Pn = -0.228 to +0.228 per Figures 8b/9); Qmin/Qmax voltage-dependent per Figure 9; below 5% Pn only a Q tolerance band of +/-5% of rated power Binds RPPs of Category B (rated power 1 MVA to 20 MVA, MV-connected), measured at the POC; operating mode (V, PF or Q control) agreed with the NSP. Read from the sseg.org.za public reprint of the identical Rev 3.1 document; the issuer copy at nersa.org.za (…/files/files/2022/01/SAGC-Requirements-for-Renewable-Power-Plants-Rev-3.1.pdf) is the primary locator but returned HTTP 403 to automated access when checked (Aug 2026).	Section 7.2(2)-(4) secondary source
The clause this row cites Section 7.2(2)-(4) — “ When operating between 5% and 100% of rated power Pn (MW) the RPP of category B shall have the capability of varying reactive power (Mvar) support at the POC within the reactive power capability ranges as defined by Figure 8a, where Qmin and Qmax are voltage dependent as defined by Figure 9. (3) At nominal voltage, the required RPP reactive power capability (measured at the POC) shall be as shown in Figure 8b. ” (Grid Connection Code for Renewable Power Plants (RPPs) Connected to the Electricity Transmission System (TS) or the Distribution System (DS) in South Africa, accessed 2026-08-10)
Primary frequency response droop and deadband (Category C) Frequency response	Each droop setting (Droop 1 / Droop 2 in Figure 7) adjustable 0% to 10%, actual setting as agreed with the SO; dead band and control band formed by settable frequency points f1-f4 (f1-f3 values agreed with SO); all points fmin, fmax, f1-f6 settable anywhere in 47-52 Hz with minimum accuracy of 10 mHz; defaults (Table 3): fmin 47 Hz, fmax 52 Hz, f4 = 50.5 Hz, f5 = 51.5 Hz, f6 = 50.2 Hz; reserve capability PDelta >= 3% of Pavailable (except PV) Binds RPPs of Category C (>= 20 MVA); contracted primary frequency response (below 50.5 Hz) requires a specific agreement with the SO — only the over-frequency response above 50.5 Hz is mandatory. Read from the sseg.org.za public reprint of the identical Rev 3.1 document; the issuer copy at nersa.org.za (…/files/files/2022/01/SAGC-Requirements-for-Renewable-Power-Plants-Rev-3.1.pdf) is the primary locator but returned HTTP 403 to automated access when checked (Aug 2026).	Section 6.2(2)-(5), (8) and Table 3 secondary source
The clause this row cites Section 6.2(2)-(5), (8) and Table 3 — “ It shall be possible to set the frequencies fmin, fmax, as well as f1 to f6 to any value in the range of 47 - 52 Hz with a minimum accuracy of 10 mHz. (4) The purpose of frequency points f1 to f4 is to form a dead band and a control band for for [sic] RPPs contracted for primary frequency response. The purpose of frequency points f4 to f6 is to supply mandatory critical power/frequency response. (5) The RPP shall be equipped with the frequency control droop settings as illustrated in figure 7. Each droop setting shall be adjustable between 0% and 10%. The actual droop setting shall be as agreed with the SO. ” (Grid Connection Code for Renewable Power Plants (RPPs) Connected to the Electricity Transmission System (TS) or the Distribution System (DS) in South Africa, accessed 2026-08-10)
Mandatory over-frequency power reduction (all RPPs) Frequency response	Mandatory active-power reduction as a function of frequency once NIPS frequency exceeds 50.5 Hz (per Figure 6, metering accuracy +/-10 mHz or better); trip required when frequency exceeds 51.5 Hz for longer than 4 s Binds all RPP categories as a mandatory (non-contracted) high-frequency response; the 50.5 Hz threshold equals default point f4 and 51.5 Hz equals default f5 in the Category C response curve. Read from the sseg.org.za public reprint of the identical Rev 3.1 document; the issuer copy at nersa.org.za (…/files/files/2022/01/SAGC-Requirements-for-Renewable-Power-Plants-Rev-3.1.pdf) is the primary locator but returned HTTP 403 to automated access when checked (Aug 2026).	Section 6.1(1)-(3) secondary source
The clause this row cites Section 6.1(1)-(3) — “ When the frequency on the NIPS exceeds 50.5 Hz, the RPP shall reduce the active power as a function of the change in frequency as illustrated in Figure 6 below. (3) Once the frequency exceed [sic] 51.5Hz for longer than 4 seconds the RPP shall be tripped to protect the NIPS. ” (Grid Connection Code for Renewable Power Plants (RPPs) Connected to the Electricity Transmission System (TS) or the Distribution System (DS) in South Africa, accessed 2026-08-10)
Continuous voltage range at POC (Table 1) Continuous operating range	Category A: continuous operation for −15% to +10% around nominal voltage at the POC; Categories B and C: continuous operation between Umin 0.90 pu and Umax 1.0985 pu (132 / 88 / 66 kV nominal) or Umax 1.08 pu (44 / 33 / 22 / 11 kV nominal), measured at the POC (Table 1) Binds Renewable Power Plants by category (A: <1 MVA in subcategories A1–A3; B: 1–20 MVA; C: ≥20 MVA) at the Point of Connection; the actual operating voltage is decided by the Network Service Provider in consultation with affected customers and implemented by the RPP generator. Storage applicability: not bound by this code's text — 'storage' does not appear anywhere in RPP Version 3.1 (full-text search, zero hits); South Africa regulates BESS through the separate NERSA Grid Connection Code for Battery Energy Storage Facilities (BESF), so this claim reaches storage only if a project instrument applies the RPP code by reference (unclear chain). Read from the sseg.org.za public reprint of the identical Rev 3.1 document; the issuer copy at nersa.org.za (…/files/files/2022/01/SAGC-Requirements-for-Renewable-Power-Plants-Rev-3.1.pdf) is the primary locator but returned HTTP 403 to automated access when checked (Aug 2026).	Grid Connection Code for RPPs in South Africa, Version 3.1 (January 2022), Section 5.1 'Normal Operating Conditions', clauses 5.1(2), 5.1(3) and Table 1 'Minimum and maximum operating voltages at POC', Page 12 + Same code and edition, clause 5.1(2), Page 12 secondary source
The clauses this row cites Grid Connection Code for RPPs in South Africa, Version 3.1 (January 2022), Section 5.1 'Normal Operating Conditions', clauses 5.1(2), 5.1(3) and Table 1 'Minimum and maximum operating voltages at POC', Page 12 — “ RPPs of Category B and C shall be designed to be capable of operating continuously within the POC voltage range specified by Umin and Umax as shown in table 1 below, measured at the POC. ” (Grid Connection Code for Renewable Power Plants (RPPs) in South Africa — Version 3.1, January 2022, accessed 2026-08-09) Same code and edition, clause 5.1(2), Page 12 — “ RPPs of Category A shall be designed to be capable of operating continuously within the voltage range of -15% to +10% around the nominal voltage at the POC. ” (Grid Connection Code for Renewable Power Plants (RPPs) in South Africa — Version 3.1, January 2022, accessed 2026-08-09)
Continuous frequency range 49.0–51.0 Hz (Figures 1–2) Continuous operating range	Continuous operating range 49.0 Hz to 51.0 Hz (Figures 1 and 2, 50 Hz nominal); above 51.5 Hz for longer than 4 s the RPP shall be disconnected; below 47.0 Hz for longer than 200 ms the RPP may be disconnected (note the shall/may asymmetry as printed) Binds all categories of RPPs (clause 5.1(1)) on the National Integrated Power System; frequency bands per Figure 1 (cumulative over plant life) and Figure 2 (during a system frequency disturbance), labelled 'Continuous Operating range (49.0 Hz to 51.0 Hz)' on Figure 1 and 'Continuous operating range (49.0 Hz to 51.0 Hz)' on Figure 2, as printed. Storage applicability: not bound by this code's text — RPP Version 3.1 never mentions storage; the separate NERSA BESF grid connection code governs BESS (chain to storage unclear absent a project instrument). Read from the sseg.org.za public reprint of the identical Rev 3.1 document; the issuer copy at nersa.org.za (…/files/files/2022/01/SAGC-Requirements-for-Renewable-Power-Plants-Rev-3.1.pdf) is the primary locator but returned HTTP 403 to automated access when checked (Aug 2026).	Grid Connection Code for RPPs in South Africa, Version 3.1 (January 2022), clause 5.1(4) with Figures 1 and 2, Pages 12–13 + Same code and edition, clauses 5.1(5) and 5.1(6), Page 13 secondary source
The clauses this row cites Grid Connection Code for RPPs in South Africa, Version 3.1 (January 2022), clause 5.1(4) with Figures 1 and 2, Pages 12–13 — “ The RPP shall be designed to be capable of operating for the minimum operating range illustrated in Figures 1 (total cumulative over the life of the RPP) and Figure 2 (during a system frequency disturbance). ” (Grid Connection Code for Renewable Power Plants (RPPs) in South Africa — Version 3.1, January 2022, accessed 2026-08-09) Same code and edition, clauses 5.1(5) and 5.1(6), Page 13 — “ When the frequency on the NIPS is higher than 51.5 Hz for longer than 4 seconds, the RPP shall be disconnected from the grid. … When the frequency on the NIPS is less than 47.0 Hz for longer than 200ms, the RPP may be disconnected. ” (Grid Connection Code for Renewable Power Plants (RPPs) in South Africa — Version 3.1, January 2022, accessed 2026-08-09)
Active-power ramp-rate control (SO/NSP-set MW/min limit) Ramp rate	Settable: RPP must be capable of limiting its active-power ramp to a maximum MW-per-minute value set by the SO or NSP (no fixed numeric cap printed in the code); applies to start-up, normal-operation upward ramps and controlled shut-down downward ramps, but not to frequency regulation; Power Gradient Constraint setpoint changes must commence within 2 s and complete within 30 s of the order (Section 11.3(2)) Binds all RPPs via the required control functions (Table 4: Power gradient constraint required for Categories A3, B and C); the ramp limit itself is plant-specific, assigned by the System Operator or Network Service Provider. Read from the sseg.org.za public reprint of the identical Rev 3.1 document; the issuer copy at nersa.org.za (…/files/files/2022/01/SAGC-Requirements-for-Renewable-Power-Plants-Rev-3.1.pdf) is the primary locator but returned HTTP 403 to automated access when checked (Aug 2026).	Section 12(2)-(3) secondary source
The clause this row cites Section 12(2)-(3) — “ The RPP control system shall be capable of controlling the ramp rate of its active power output with a maximum MW per minute ramp rate set by SO or NSP. (3) These ramp rate settings shall be applicable for all ranges of operation including positive ramp rate during start up, positive ramp rate only during normal operation and negative ramp rate during controlled shut down. They shall not apply to frequency regulation. ” (Grid Connection Code for Renewable Power Plants (RPPs) Connected to the Electricity Transmission System (TS) or the Distribution System (DS) in South Africa, accessed 2026-08-10)
RoCoF ride-through RoCoF withstand	Remain connected for rate-of-change-of-frequency up to and including 1.5 Hz/s (no measurement/averaging window stated), provided frequency stays within the minimum operating range of Figures 1 and 2 Binds all RPP categories at the POC under the frequency-tolerance requirements (nominal system frequency 50 Hz; disconnection permitted below 47.0 Hz after 200 ms per clause 5.1(6) and required above 51.5 Hz after 4 s per clause 5.1(5)). Read from the sseg.org.za public reprint of the identical Rev 3.1 document; the issuer copy at nersa.org.za (…/files/files/2022/01/SAGC-Requirements-for-Renewable-Power-Plants-Rev-3.1.pdf) is the primary locator but returned HTTP 403 to automated access when checked (Aug 2026).	Section 5.1(7) secondary source
The clause this row cites Section 5.1(7) — “ The RPP shall remain connected to the NIPS during rate of change of frequency of values up to and including 1.5 Hz per second, provided the network frequency is still within the minimum operating range indicated in Figures 1 and 2. ” (Grid Connection Code for Renewable Power Plants (RPPs) Connected to the Electricity Transmission System (TS) or the Distribution System (DS) in South Africa, accessed 2026-08-10)
Reactive-current voltage support per Figure 5 (Categories B and C) Fault-current injection	Categories B and C: controlled reactive-current injection for maximum voltage support per Figure 5 — supply in Area B (voltage dips), Category C only: absorb in Area D (voltage peaks, Umax to 1.2 pu) — clause 5.2.1(b)(1) limits Area D to Category C RPPs; the Figure 5 characteristic runs from 0% additional reactive current (ΔIq/In) at Umin to 100% at U = 0.5 pu (axis −110% under-excited to +110% over-excited); control tolerance ±20% after 60 ms; reactive power has first priority in Area B; below 20% voltage (Area E) reactive current continues within design limits; ≥90% of the active power available immediately prior to the fault, restored within 1 s of fault clearance; Category A3 shall not inject any reactive current Binds Categories B and C only — the quoted duty names them and no others, and Category A3 must not inject. Applies at the POC for symmetrical fault sequences in Area B (Categories B and C) and Area D (Category C only, per clause 5.2.1(b)(1)) of the ride-through figures (clause 5.2.1(b)(8)); inverter-driven Category B and C RPPs must be able to disable reactive-current support at the request of the SO or local network operator. No numeric k-factor is printed in Version 3.1 — the gain is given graphically by Figure 5 (from its anchor points a slope of ≈2.5% additional reactive current per 1% voltage deviation below Umin can be derived; Derived value, not printed). Negative-sequence injection is not required — the reactive-current control duty is written for symmetrical fault sequences. Storage applicability: not bound by this code's text (zero mentions of storage in RPP v3.1; the separate NERSA BESF code governs BESS). Read from the sseg.org.za public reprint of the identical Rev 3.1 document; the issuer copy at nersa.org.za (…/files/files/2022/01/SAGC-Requirements-for-Renewable-Power-Plants-Rev-3.1.pdf) is the primary locator but returned HTTP 403 to automated access when checked (Aug 2026).	Grid Connection Code for RPPs in South Africa, Version 3.1 (January 2022), Section 5.2.1 'Tolerance to sudden voltage drops and peaks', subsection (b) 'RPPs of Categories A3, B and C', items (8)–(11), Page 18, and Figure 5 'Requirements for Reactive Power Support, IQ, during voltage drops or peaks at the POC', Page 19 + Same code and edition, Section 5.2.1(b), item (9), Page 18 secondary source
The clauses this row cites Grid Connection Code for RPPs in South Africa, Version 3.1 (January 2022), Section 5.2.1 'Tolerance to sudden voltage drops and peaks', subsection (b) 'RPPs of Categories A3, B and C', items (8)–(11), Page 18, and Figure 5 'Requirements for Reactive Power Support, IQ, during voltage drops or peaks at the POC', Page 19 — “ RPPs of category B and category C shall provide maximum voltage support by supplying a controlled amount of reactive current so as to ensure that the RPP assists in stabilising the voltage as shown in Figure 5; ” (Grid Connection Code for Renewable Power Plants (RPPs) in South Africa — Version 3.1, January 2022, accessed 2026-08-09) Same code and edition, Section 5.2.1(b), item (9), Page 18 — “ Control shall follow Figure 5 so that the reactive current follows the control characteristic with a tolerance of ±20% after 60 ms. ” (Grid Connection Code for Renewable Power Plants (RPPs) in South Africa — Version 3.1, January 2022, accessed 2026-08-09)

Scope

Who does South Africa (NRS 097 / RPP) bind, and since when?

RPP categories A3/B/C on transmission or distribution. No date of effect is published here — grid codes are reissued, so check the current issue before relying on it.

These figures are a reading aid, not legal advice. Grid codes are reissued: verify against the current edition before you design to them.

Curve data last checked against the code on 2026-08-11 — 66 standards, 130 envelopes, published by bess.engineer under CC BY 4.0.

Questions

Questions this page answers about South Africa (NRS 097 / RPP)

Does South Africa (NRS 097 / RPP) require ride-through, or only that the plant does not trip?: Ride-through, for the envelopes on this page — that is what each of them is. It is not everything South Africa (NRS 097 / RPP) contains: the clauses quoted under the charts also address when the plant may or must trip. The requirement sentence under each chart says which side of the curve is the compliant one.
Are the numbers on this page taken from South Africa (NRS 097 / RPP) itself?: Every breakpoint is read from the code, and where a point was taken off a published figure rather than stated in the clause, the section under that chart says so — on this page that includes an envelope that stops where its published chart stops. The clause each curve came from is quoted under it.
Which events are charted for South Africa (NRS 097 / RPP)?: South Africa (NRS 097 / RPP) is charted here with 3 envelopes — low-voltage ride-through, high-voltage ride-through, frequency ride-through (LVRT, HVRT, FRT).

Ride-through, in context.

An envelope is a compliance boundary; understanding why it exists is a different question. The ride-through and grid-forming entries cover the engineering, and the Engineering Foundations course builds it from the physics up.

Elsewhere in Africa: Kenya (KNTGC VRPP), Morocco (CRENT), Nigeria (TCN Grid Code)

Other markets: Saudi Arabia (SAGC), UK G99 (Type A-C), UK G99 (Type D)

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