Brazil (ONS Submódulo 2.10) ride-through requirements
Low-voltage ride-through, High-voltage ride-through, Frequency ride-through for Brazil. 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 — a curve read off a figure the clause states no numbers for.
What is the low-voltage ride-through envelope for Brazil (ONS Submódulo 2.10)?
The plant must ride through for any voltage that stays on or above this envelope. The envelope holds 0.2 pu from t = 0 to 500 ms; then ramps linearly from 0.2 pu at 500 ms to 0.85 pu at 1 s; then 0.85 pu from 1 s to 5 s; then 0.9 pu from 5 s onward — the last band the envelope defines, with no stated end time.
The clause states this boundary as a line, but does not give its vertices numerically — the points plotted here were read off the published figure.
Applies to Converter-connected wind and PV plants joining the transmission system (Rede Básica, ICG or DIT)
| From | To | Voltage | Between the points |
|---|---|---|---|
| 0 | 500 ms | 0.2 pu | Held flat |
| 500 ms | 1 s | 0.2 → 0.85 pu | Ramps linearly |
| 1 s | 5 s | 0.85 pu | Held flat |
| 5 s | no stated end | 0.9 pu | Held flat |
The clause this came from
ONS, Procedimentos de Rede, Submódulo 2.10 'Requisitos técnicos mínimos para a conexão às instalações de transmissão', Revisão 2025.02 (aprovada pela REN ANEEL nº 1.112/2025 de 11/02/2025; vigência 01/03/2025), item 5.7 'Suportabilidade a subtensões e sobretensões dinâmicas' and Figura 13 'Tensão nos terminais dos aerogeradores ou inversores da central geradora' — lower boundary. The clause states no numbers; every value is read from the figure. Measured at the wind turbine or inverter terminals, not at the point of connection, and satisfied by the phase with the largest variation. Section 5 governs converter-connected wind and photovoltaic plants; synchronous hydro and thermal plant follow item 4.2 with materially different bands. Current index: https://www.ons.org.br/paginas/sobre-o-ons/procedimentos-de-rede/vigentes. Supersedes Submódulo 3.6 rev. 2019.08, whose numbering now belongs to an unrelated submodule on system-service charges.
What is the high-voltage ride-through envelope for Brazil (ONS Submódulo 2.10)?
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 2.5 s; then 1.1 pu from 2.5 s onward — the last band the envelope defines, with no stated end time.
The plotted points approximate the boundary the clause states.
Applies to Converter-connected wind and PV plants joining the transmission system (Rede Básica, ICG or DIT)
| From | To | Voltage | Between the points |
|---|---|---|---|
| 0 | 2.5 s | 1.2 pu | Held flat |
| 2.5 s | no stated end | 1.1 pu | Held flat |
The clause this came from
ONS, Procedimentos de Rede, Submódulo 2.10 'Requisitos técnicos mínimos para a conexão às instalações de transmissão', Revisão 2025.02 (aprovada pela REN ANEEL nº 1.112/2025 de 11/02/2025; vigência 01/03/2025), item 5.7 'Suportabilidade a subtensões e sobretensões dinâmicas' and Figura 13 — upper boundary of the must-remain-in-operation region: 1,20 pu to 2,5 s, then 1,10 pu. The clause states no numbers; every value is read from the figure. Section 5 governs converter-connected wind and photovoltaic plants; synchronous hydro and thermal plant follow item 4.2 with materially different bands. Current index: https://www.ons.org.br/paginas/sobre-o-ons/procedimentos-de-rede/vigentes. Supersedes Submódulo 3.6 rev. 2019.08, whose numbering now belongs to an unrelated submodule on system-service charges.
What is the frequency ride-through envelope for Brazil (ONS Submódulo 2.10)?
The plant must ride through between the upper and lower bands. The upper (over-frequency) band holds 63 Hz from t = 0 to 10 s; then 62.5 Hz from 10 s onward — the last band the envelope defines, with no stated end time. The lower (under-frequency) band holds 56 Hz from t = 0 to 20 s; then 58.5 Hz from 20 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 Converter-connected wind and PV plants joining the transmission system (Rede Básica, ICG or DIT)
Upper limit
| From | To | Frequency | Between the points |
|---|---|---|---|
| 0 | 10 s | 63 Hz | Held flat |
| 10 s | no stated end | 62.5 Hz | Held flat |
Lower limit
| From | To | Frequency | Between the points |
|---|---|---|---|
| 0 | 20 s | 56 Hz | Held flat |
| 20 s | no stated end | 58.5 Hz | Held flat |
The clause this came from
ONS, Procedimentos de Rede, Submódulo 2.10 'Requisitos técnicos mínimos para a conexão às instalações de transmissão', Revisão 2025.02 (aprovada pela REN ANEEL nº 1.112/2025 de 11/02/2025; vigência 01/03/2025), item 5.2.1 'Operação em regime de frequência não nominal' sub-items (a)-(e), summarised by Figura 5 'Faixas de operação da central geradora em regime de frequência não nominal': instantaneous disconnection permitted below 56 Hz; below 58,5 Hz for at least 20 s; 58,5-62,5 Hz unlimited; above 62,5 Hz for at least 10 s; instantaneous disconnection permitted above 63 Hz. Sub-item (d) adds that the overfrequency trip delay is set from a dynamic-performance study, so the 10 s is a floor rather than the setting. Section 5 governs converter-connected wind and photovoltaic plants; synchronous hydro and thermal plant follow item 4.2 with materially different bands. Current index: https://www.ons.org.br/paginas/sobre-o-ons/procedimentos-de-rede/vigentes. Supersedes Submódulo 3.6 rev. 2019.08, whose numbering now belongs to an unrelated submodule on system-service charges.
Operating requirements beyond the envelopes.
The envelopes above are what Brazil (ONS Submódulo 2.10) 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 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.
| Requirement | What the code states | Clause |
|---|---|---|
| P-Q envelope at POI: Q/Pmax ±0,329 (FP 0,95), Pmax = contracted MUST Reactive capability | Steady-state operation required at any point of the Figure 6 area at the connection point: Q/Pmax from -0,329 (indutivo) to +0,329 (capacitivo), corresponding to FP = 0,95 at P/Pmax = 1,0; the full ±0,329 width is held down to P/Pmax = 0,2, below which the envelope tapers to zero Q at zero P (values -0,329 / 0,329 / 0,2 / FP=0,95 read from the Figure 6 axis labels on the page image). The Pmax basis is the contracted MUST (Montante de Uso do Sistema de Transmissão) at the connection point. Binds wind and photovoltaic centrais geradoras under section 5 (transmission-connected; also certain DIT/distribution cases per §5.1.2), at the point of connection to transmission-agent installations, in regime permanente. Storage is not mentioned anywhere in section 5; battery plants are neither named nor excluded — storage treatment is unclear in this revision. Hybrid/associated plants: wind/PV technologies within them are bound to these section-5 requirements via §6.1.3(b). §5.2.2.3 additionally requires zero net reactive exchange capability at the POI when the generators produce no active power (paraphrase, clause cited). The §5.2.2.1 quote below prints "Figura 4" — an apparent cross-reference typo in the document itself; the P-Q envelope it describes is Figura 6, and the quote is reproduced as printed. | §5.2.2, §5.2.2.1 and Figura 6 - Faixa de geração/absorção de potência reativa no ponto de conexão da central geradora + §5.2.2.1 |
The clauses this row cites§5.2.2, §5.2.2.1 and Figura 6 - Faixa de geração/absorção de potência reativa no ponto de conexão da central geradora — “ Geração/absorção de potência reativa: na conexão da central geradora às instalações sob responsabilidade de agente de transmissão, as centrais geradoras devem propiciar os recursos necessários para, em regime permanente, operar com fator de potência indutivo ou capacitivo em qualquer ponto da área indicada na Figura 6. ” Translation: “ Reactive power generation/absorption: at the connection of the generating plant to the installations under the responsibility of a transmission agent, the generating plants must provide the resources needed to operate, in steady state, with inductive or capacitive power factor at any point of the area indicated in Figure 6. ” (ONS Procedimentos de Rede, Submódulo 2.10, Revisão 2025.02, accessed 2026-08-08) §5.2.2.1 — “ A potência ativa máxima a ser considerada como referência na Figura 4 é o Montante de Uso do Sistema de Transmissão (MUST) contratado no respectivo ponto de conexão, conforme o Submódulo 8.1 – Administração dos Contratos. ” Translation: “ The maximum active power to be considered as the reference in Figure 4 is the Montante de Uso do Sistema de Transmissão (MUST) [amount of transmission system use] contracted at the respective connection point, in accordance with Submódulo 8.1 – Administração dos Contratos [Administration of Contracts]. ” (ONS Procedimentos de Rede, Submódulo 2.10, Revisão 2025.02, accessed 2026-08-08) | ||
| Proportional PFR >10 MW: deadband 0,1 Hz default (0,040–0,2), droop 5% default (2–8%) Frequency response | Plants with installed capacity above 10 MW must have proportional frequency-sensitive controllers (Figura 11). Tabela 2 settings: under- and over-frequency deadband (bmUF, bmOF) default 0,1 Hz, adjustable 0,040–0,2 Hz; under- and over-frequency droop (kUF, kOF) default 5%, adjustable 2–8%, on the nominal-power base ('na base de potência nominal'); PMIN not above 25% of plant nominal capacity. Dynamic performance per Tabela 3: tempo de reação ≤1 s; tempo de resposta (to 90% of final value at the POI) ≤10 s for ΔP < 50% and ≤30 s for ΔP ≥ 50% of nominal power. No operating reserve is required — underfrequency injection uses spare capacity when available (§5.2.9(g)). Binds wind and PV centrais geradoras (section 5) with potência instalada > 10 MW, measured at the connection point. Storage not mentioned; BESS applicability unstated in this revision. Basis caution: droop is on nominal power, not on MUST/Pmax. Tabela 2 and Tabela 3 values transcribed from the tables on PDF pp. 27–28 (page images checked). Note Tabela 3's 'Tempo de estabilização' cell for ΔP ≥ 50% prints as '1. s' in the PDF — an apparent typographical defect; not relied on here. | §5.2.9(a), Tabela 2 – Ajustes padrão e faixas de ajustes do controle primário de frequência, Tabela 3 – Requisito de desempenho dinâmico do controle primário de frequência + §5.2.9(g) |
The clauses this row cites§5.2.9(a), Tabela 2 – Ajustes padrão e faixas de ajustes do controle primário de frequência, Tabela 3 – Requisito de desempenho dinâmico do controle primário de frequência — “ As centrais geradoras com potência instalada superior a 10 MW devem dispor de controladores sensíveis às variações de frequência do tipo proporcional, conforme Figura 11, com os ajustes padrão e faixas de ajuste dos parâmetros indicados na Tabela 2. ” Translation: “ Generating plants with installed capacity above 10 MW must have controllers sensitive to frequency variations, of the proportional type, per Figure 11, with the default settings and parameter adjustment ranges indicated in Table 2. ” (ONS Procedimentos de Rede, Submódulo 2.10, Revisão 2025.02, accessed 2026-08-08) §5.2.9(g) — “ O requisito de injeção de potência ativa em condição de subfrequência de que trata o item 5.2.9. (a) não implica em estabelecimento de reserva de potência operativa para centrais geradoras, mas na utilização, quando disponível, de eventual capacidade ociosa da central de geração. ” Translation: “ The requirement for active power injection in an underfrequency condition dealt with in item 5.2.9. (a) does not imply the establishment of an operating power reserve for generating plants, but rather the use, when available, of any idle capacity of the generating plant. ” (ONS Procedimentos de Rede, Submódulo 2.10, Revisão 2025.02, accessed 2026-08-08) | ||
| Frequency bands: 58,5–62,5 Hz unlimited; ≥20 s below 58,5; ≥10 s above 62,5; trip allowed <56 / >63 Hz Continuous operating range | Non-nominal-frequency operating envelope (Figura 5): continuous (unlimited-time) operation 58,5–62,5 Hz; operation below 58,5 Hz for at least 20 s; operation above 62,5 Hz for at least 10 s (overfrequency trip timing set from a dynamic-performance assessment); instantaneous disconnection permitted below 56 Hz and above 63 Hz. Binds wind and PV centrais geradoras (section 5, converter-connected) — synchronous hydro/thermal plants follow item 4.2 with different bands. Storage applicability unstated. Related output constraint (§5.2.7(c)-(d), PDF p.25, paraphrase): no active-power output reduction is admitted for 58,5–60,0 Hz with 0,85–1,10 pu voltage at the POI; for 57–58,5 Hz a reduction of up to 10% is admitted. Note nominal frequency in Brazil is 60 Hz. | §5.2.1 items (a)–(e); §5.2.1.1 and Figura 5 - Faixas de operação da central geradora em regime de frequência não nominal |
The clause this row cites§5.2.1 items (a)–(e); §5.2.1.1 and Figura 5 - Faixas de operação da central geradora em regime de frequência não nominal — “ Em operação em regime de frequência não nominal, deve-se atender às seguintes condições: (a) desligamento instantâneo permitido para operação abaixo de 56 Hz; (b) operação abaixo de 58,5 Hz por período de tempo mínimo de 20 s; (c) operação entre 58,5 e 62,5 Hz por tempo ilimitado; (d) operação acima de 62,5 Hz por período de tempo mínimo de 10 s, sendo a temporização da proteção de desligamento por sobrefrequência é definida com base em avaliação do desempenho dinâmico, para garantir a segurança operativa do SIN; e (e) desligamento instantâneo permitido para operação acima de 63 Hz. ” Translation: “ In operation under non-nominal frequency conditions, the following conditions must be met: (a) instantaneous disconnection permitted for operation below 56 Hz; (b) operation below 58.5 Hz for a minimum period of 20 s; (c) operation between 58.5 and 62.5 Hz for unlimited time; (d) operation above 62.5 Hz for a minimum period of 10 s, with the timing of the overfrequency disconnection protection being defined based on a dynamic-performance assessment, to ensure the operational security of the SIN; and (e) instantaneous disconnection permitted for operation above 63 Hz. ” (ONS Procedimentos de Rede, Submódulo 2.10, Revisão 2025.02, accessed 2026-08-08) | ||
| Voltage bands at POI: contingency range unlimited; 0,85–0,90 pu ≥5 s; 500 kV 1,10–1,20 pu ≥2,5 s Continuous operating range | Non-nominal-voltage operation at the POI: (a) unlimited time within the admissible-voltage range of Submódulo 2.3 (contingency operating condition); (b) 0,85–0,90 pu for at least 5 s (voltage levels other than 500 kV); (c) 0,90–0,95 pu for at least 5 s (500 kV systems); (d) 1,10–1,20 pu for at least 2,5 s (500 kV systems); (e) up to 0,10 pu above the maximum contingency operating voltage for at least 2,5 s (other voltage levels). Binds wind and PV centrais geradoras (section 5) at the point of connection to transmission-agent installations. These are time-limited steady-state operating bands, distinct from the dynamic voltage ride-through curve of §5.7/Figura 13, a terminal-voltage curve covered by the ride-through charts published for this code and not repeated here. The continuous band itself is not numerically printed here: it is defined by reference to the 60 Hz phase-to-phase admissible-voltage criterion of Submódulo 2.3. Storage applicability unstated. | §5.2.4 items (a)–(e) |
The clause this row cites§5.2.4 items (a)–(e) — “ Na operação em regime de tensão não nominal, no ponto de conexão da central geradora às instalações sob responsabilidade de agente de transmissão, a central geradora deve ser capaz de operar: (a) na faixa de tensão conforme critério de tensão admissível entre fases a 60 Hz estabelecido no Submódulo 2.3, condição operativa sob contingências, por período de tempo ilimitado; (b) entre 0,85 e 0,90 pu da tensão nominal, para os demais níveis de tensão, por período de tempo mínimo de 5 segundos; (c) entre 0,90 e 0,95 pu da tensão nominal, para sistemas de 500 kV, por período de tempo mínimo de 5 segundos; (d) entre 1,10 e 1,20 pu, para sistemas de 500 kV, por período de tempo mínimo de 2,5 segundos; e (e) até 0,10 pu acima da máxima tensão operativa sob contingência, para os demais níveis de tensão, por período de tempo mínimo de 2,5 segundos. A máxima tensão operativa sob contingência é definida conforme critério de tensão admissível entre fases a 60 Hz estabelecido no Submódulo 2.3. ” Translation: “ In operation under non-nominal voltage conditions, at the point of connection of the generating plant to the installations under the responsibility of a transmission agent, the generating plant must be capable of operating: (a) within the voltage range per the criterion of admissible phase-to-phase voltage at 60 Hz established in Submódulo 2.3, operating condition under contingencies, for an unlimited period of time; (b) between 0.85 and 0.90 pu of nominal voltage, for the other voltage levels, for a minimum period of 5 seconds; (c) between 0.90 and 0.95 pu of nominal voltage, for 500 kV systems, for a minimum period of 5 seconds; (d) between 1.10 and 1.20 pu, for 500 kV systems, for a minimum period of 2.5 seconds; and (e) up to 0.10 pu above the maximum contingency operating voltage, for the other voltage levels, for a minimum period of 2.5 seconds. The maximum contingency operating voltage is defined per the criterion of admissible phase-to-phase voltage at 60 Hz established in Submódulo 2.3. ” (ONS Procedimentos de Rede, Submódulo 2.10, Revisão 2025.02, accessed 2026-08-08) | ||
| Loading rate: adjustable, settings defined by ONS — no numeric limit printed Ramp rate | No numeric ramp-rate limit (MW/min or %/min) is stated. §5.9.1 requires only that the plant be equipped with means to adjust its loading (tomada de carga) rate, with the settings defined by ONS. Post-fault active-power recovery ramp is likewise ONS-defined case by case (§5.2.7(b)). Binds wind and PV centrais geradoras (section 5) as a capability requirement; the actual rate is a project-specific ONS setting, not a code-wide number. No separate charge/discharge treatment (the code has no storage provisions). Storage applicability unstated in this revision. | §5.9.1 (Tomada de carga) + §5.2.7(b) |
The clauses this row cites§5.9.1 (Tomada de carga) — “ A central geradora deve ser dotada de recursos que permitam ajustar a taxa de tomada de carga da central geradora. Os ajustes serão definidos pelo ONS. ” Translation: “ The generating plant must be equipped with resources that allow adjusting the loading rate of the generating plant. The settings will be defined by the ONS. ” (ONS Procedimentos de Rede, Submódulo 2.10, Revisão 2025.02, accessed 2026-08-08) §5.2.7(b) — “ Cabe ao ONS a responsabilidade de definir a rampa de recuperação da potência em função das características do sistema onde as centrais serão inseridas. ” Translation: “ It is the responsibility of the ONS [Operador Nacional do Sistema Elétrico, National Electric System Operator] to define the power recovery ramp as a function of the characteristics of the system into which the plants will be inserted. ” (ONS Procedimentos de Rede, Submódulo 2.10, Revisão 2025.02, accessed 2026-08-08) | ||
| Dynamic reactive current: inject below 85% V+, absorb above 110%, start ≤30 ms, defaults V1=0,5 / V2=1,2 pu Fault-current injection | Voltage support during transient voltage variations per Figura 14: additional reactive current injection for positive-sequence voltages below 85%, and additional positive-sequence reactive current absorption for voltages above 110%; supply of reactive current must start within 30 ms of fault detection (control response time); the feature must be enabled by default with V1 = 0,5 pu and V2 = 1,2 pu (ONS may change these settings). Figura 14 plots ΔIQ/In from +1 (at V1) to −1, with the no-action band between 0,85 and 1,10 pu; no explicit numeric gain k (% current per % voltage) is printed — the slope is defined only graphically. Binds the unidades geradoras (wind turbines / inverters) of section-5 wind and PV plants; voltages are positive-sequence at the equipment terminals per the Figura 14 legend (Vpos/Vn). Priority under current limit (§5.8.4, PDF p.31, paraphrase): active-power output may be reduced only if the added reactive current would otherwise exceed the equipment's nominal current — i.e. reactive-current increment takes precedence up to the nominal-current ceiling. Storage applicability unstated in this revision. | §5.8.1 (a)-(b) and Figura 14 - Requisito para injeção de corrente reativa sob defeito + §5.8.2; §5.8.3 |
The clauses this row cites§5.8.1 (a)-(b) and Figura 14 - Requisito para injeção de corrente reativa sob defeito — “ Quando de variações transitórias de tensão, conforme mostrado na Figura 14, as unidades geradoras devem ser capazes de dar suporte de tensão à rede elétrica através da: (a) injeção de corrente reativa adicional para tensões de sequência positiva inferiores a 85%; e (b) absorção de corrente reativa adicional de sequência positiva para tensões acima de 110%. ” Translation: “ During transient voltage variations, as shown in Figure 14, the generating units must be capable of providing voltage support to the electrical network through: (a) injection of additional reactive current for positive-sequence voltages below 85%; and (b) absorption of additional positive-sequence reactive current for voltages above 110%. ” (ONS Procedimentos de Rede, Submódulo 2.10, Revisão 2025.02, accessed 2026-08-08) §5.8.2; §5.8.3 — “ As unidades geradoras devem ser capazes de iniciar o suprimento de corrente reativa em até 30 ms após a detecção de falta (tempo de resposta do controle). … As centrais devem habilitar por padrão este recurso com os ajustes V1 = 0,5 pu e V2 = 1,2 pu. Cabe ao ONS indicar a necessidade de alterar estes ajustes, em função das características do sistema onde a central geradora será inserida. ” Translation: “ The generating units must be capable of initiating the supply of reactive current within at most 30 ms after fault detection (control response time). … The plants must enable this feature by default with the settings V1 = 0.5 pu and V2 = 1.2 pu. It is up to the ONS to indicate the need to change these settings, depending on the characteristics of the system where the generating plant will be inserted. ” (ONS Procedimentos de Rede, Submódulo 2.10, Revisão 2025.02, accessed 2026-08-08) | ||
Who does Brazil (ONS Submódulo 2.10) bind, and since when?
Converter-connected wind and PV plants joining the transmission system (Rede Básica, ICG or DIT). 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 — 66 standards, 130 envelopes, published by bess.engineer under CC BY 4.0.
Questions this page answers about Brazil (ONS Submódulo 2.10)
- Does Brazil (ONS Submódulo 2.10) 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 Brazil (ONS Submódulo 2.10) 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 Brazil (ONS Submódulo 2.10) 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 a curve read off a figure the clause states no numbers for. The clause each curve came from is quoted under it.
- Which events are charted for Brazil (ONS Submódulo 2.10)?
- Brazil (ONS Submódulo 2.10) 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 South America: Argentina (CAMMESA PT-4 Anexo I, Fig. Ai.1), Argentina (CAMMESA PT-4), Colombia (CREG 060/2019), Ecuador (ARCONEL-001/24 Código de Conexión), Panama (Código de Redes Fotovoltaico 2017), Peru (COES PR-20, Anexo 1 Cap. 4), and 2 more