Malaysia (Grid Code Additional Code 2025) ride-through requirements
Low-voltage ride-through, Frequency ride-through for Malaysia. 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.
What is the low-voltage ride-through envelope for Malaysia (Grid Code Additional Code 2025)?
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 0.9 pu at 1.5 s; then 0.9 pu from 1.5 s, plotted to 5 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 PPMs and energy storage units on the Peninsular grid system
| From | To | Voltage | Between the points |
|---|---|---|---|
| 0 | 150 ms | 0 pu | Held flat |
| 150 ms | 1.5 s | 0 → 0.9 pu | Ramps linearly |
| 1.5 s | plotted to 5 s | 0.9 pu | Held flat |
The clause this came from
Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 (Suruhanjaya Tenaga), Connection Code CC.6.4.15.2 and Figure 6 'Power Park Modules and Energy Storage Units Fault Ride Through Requirements'; definition of Energy Storage Unit; CC.6.2.4.1. The code defines a linear recovery ramp; the vertices are read from the clause and the chart draws the segment between them.
What is the frequency ride-through envelope for Malaysia (Grid Code Additional Code 2025)?
The plant must ride through between the upper and lower bands. The upper (over-frequency) band holds 52 Hz from t = 0 to 60 min; then 51.5 Hz from 60 min to 90 min; then 50.5 Hz from 90 min onward — the last band the envelope defines, with no stated end time. The lower (under-frequency) band holds 47 Hz from t = 0 to 10 s; then 47.5 Hz from 10 s to 90 min; then 49.5 Hz from 90 min onward — the last band the envelope defines, with no stated end time.
Every breakpoint is stated in the clause cited below.
Applies to PPMs and energy storage units on the Peninsular grid system
Upper limit
| From | To | Frequency | Between the points |
|---|---|---|---|
| 0 | 60 min | 52 Hz | Held flat |
| 60 min | 90 min | 51.5 Hz | Held flat |
| 90 min | no stated end | 50.5 Hz | Held flat |
Lower limit
| From | To | Frequency | Between the points |
|---|---|---|---|
| 0 | 10 s | 47 Hz | Held flat |
| 10 s | 90 min | 47.5 Hz | Held flat |
| 90 min | no stated end | 49.5 Hz | Held flat |
The clause this came from
Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, Connection Code CC.6.2.3.2 frequency range table.
Operating requirements beyond the envelopes.
The envelopes above are what Malaysia (Grid Code Additional Code 2025) 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.
| Requirement | What the code states | Clause |
|---|---|---|
| ESU reactive envelope (Figure 3) Reactive capability | At Registered Capacity, HV side of step-up transformer: discharge points A/B at Q/P −0.33 (leading) to +0.62 (lagging); charge points C/D at Q/P +0.33 (leading) to −0.62 (lagging); prose labels both limits 'power factor of 0.9' — published as printed; the figures compute to PF 0.95 and 0.85, and Figure 4 under CC.6.4.2.6 prints exactly 0.85/0.95 on its power-factor axis Binds Energy Storage Units explicitly ('All Energy Storage Units must be capable of generating Reactive Power at a high voltage level of their step-up transformer at the Registered Capacity'). Applicability chain: CC.6.4 applies to Generating Modules and Energy Storage Units of Type B (CC.6.4.1.1), Type B defined in MCC.3.3 of the Main Code KOD/ST/No.8/2025 as any Generating Module or Energy Storage Unit at or above the Type A thresholds (inverter-connected threshold: 10 MW). Figure 3 chart itself (PDF p.100) prints no numeric Q/P axis values; the numbers appear only in the prose paragraph under the Figure 3 caption. Sign convention as printed: leading = absorbing reactive power, lagging = generating reactive power; the Q/P signs reverse between discharge (A/B) and charge (C/D). | Connection Code CC.6.4.2.2 and Figure 3 (Energy Storage Unit Reactive Power Requirement During Normal Operation), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 + Connection Code CC.6.4.2.2 (Energy Storage Unit paragraph introducing Figure 3), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 |
The clauses this row citesConnection Code CC.6.4.2.2 and Figure 3 (Energy Storage Unit Reactive Power Requirement During Normal Operation), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ Points A and B are when the Energy Storage Unit is supplying maximum Active Power to the Grid (discharge mode) and C and D are when the Energy Storage Unit is consuming maximum Active Power from Grid (charging mode). Points A and C are when the Energy Storage Unit is absorbing Reactive Power at power factor of 0.9 leading (Q/P ratio of -0.33 and 0.33 respectively). Points B and D are when the Energy Storage Unit is generating Reactive Power at a power factor of 0.9 lagging (Q/P ratio of 0.62 and -0.62 respectively. ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) Connection Code CC.6.4.2.2 (Energy Storage Unit paragraph introducing Figure 3), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ All Energy Storage Units must be capable of generating Reactive Power at a high voltage level of their step-up transformer at the Registered Capacity. Figure 3 below shows the minimum required reactive capability characteristic for an Energy Storage Unit. ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) | ||
| Q availability over ±10% voltage + AVC Reactive capability | Reactive Power output should be fully available within ±10% voltage at 500kV, 275kV and 132kV ('should'); continuously acting automatic voltage control is mandatory ('must') over the entire operating range Binds Power Park Modules and Energy Storage Units explicitly (Type B per CC.6.4.1.1 → Main Code MCC.3.3). Measured at steady state; Figure 4 (Power Park Module and Energy Storage Unit Reactive Power Requirement During Normal Operation, PDF p.102) plots voltage at Connection Point 0.90–1.10 p.u. against a power-factor axis printed 0.85 (lagging/overexcited) to 0.95 (leading/underexcited). Voltage-control plant may be located at the unit terminals, an intermediate busbar, or the Connection Point; below 20% of Rated MW the automatic control system may continue voltage control using available reactive capability. Note the two modals: Q availability over ±10% is 'should'; the automatic voltage control equipment requirement is 'must'. | Connection Code CC.6.4.2.6 and Figure 4, Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 + Connection Code CC.6.4.2.6 (paragraph following Figure 4), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 |
The clauses this row citesConnection Code CC.6.4.2.6 and Figure 4, Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ For any Power Park Module or Energy Storage Unit, the Reactive Power output under steady state conditions, should be fully available within the range +/- 10% at 500kV, 275kV and 132kV where the requirement and limits shown in the figure below applies. ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) Connection Code CC.6.4.2.6 (paragraph following Figure 4), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ Power Park Modules and Energy Storage Unit must be equipped with continuously acting automatic control to provide control of the voltage without instability over the entire operating range of the Power Park Module or Energy Storage Unit. ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) | ||
| Droop 2–5%, deadband ≤0.05 Hz Frequency response | Speed governor or equivalent settable to overall droop between 2% and 5%; deadband adjustable as agreed with GSO, with maximum combined effect of frequency-response insensitivity plus deadband not exceeding 0.05 Hz (±0.025 Hz) Binds 'the Generating Modules or an Energy Storage Unit of type B' explicitly — storage is named in both sub-paragraphs (Type B per Main Code MCC.3.3: at or above 10 MW for inverter-connected). CC.6.4.4.4 requires each Type B Generating Module or Energy Storage Unit to be fitted with a speed governor or equivalent controlling Active Power output over the entire operating range. For Power Park Modules of Type B the droop-equivalent parameter is a fixed setting (value set by the GSO) between 2% and 5% per Power Park Unit in service; the code does not print a separate fixed-droop sentence for ESUs, whose droop must be 'capable of being set' in the 2–5% range. Modals: droop capability 'must'; deadband adjustability 'should ... adjustable', with the 0.05 Hz cap phrased 'cannot exceed'. | Connection Code CC.6.4.4.5(b), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 + Connection Code CC.6.4.4.5(c), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 |
The clauses this row citesConnection Code CC.6.4.4.5(b), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ the speed governor or equivalent control for the Generating Modules or an Energy Storage Unit of type B must be capable of being set so that it operates with an overall speed droop between 2% and 5%. Lower droop setting capability may be specified for Hydro Units by the Grid Owner and the GSO. ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) Connection Code CC.6.4.4.5(c), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ in the case of all Generating Modules or Energy Storage Unit of type B the speed governor (or its equivalent) dead band should be adjustable as agreed with the GSO. However, the maximum combined effect of the frequency response insensibility and the frequency dead band cannot exceed 0.05Hz (for the avoidance of doubt, ±0.025Hz). ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) | ||
| Minimum response ≥2% per 0.1 Hz Frequency response | Minimum frequency response of not less than 2% of Registered Capacity per 0.1 Hz change for deviations of 0.5 Hz or less (10% of Registered Capacity at 0.5 Hz deviation); response for deviations beyond 0.5 Hz not less than the 0.5 Hz response Appendix 3 profile text (CCA.3.3.1/CCA.3.3.2) is written for 'Generating Module of types B'; Energy Storage Units are bound through CC.6.4.4.7, which names Energy Storage Units and directs them to the Appendix 3 profile, and through the Appendix 3 test definitions CCA.3.4.2/CCA.3.4.3, which define the Primary Response capability (minimum increase in Active Power output between 10 and 30 seconds after the start of the test ramp injection) and Secondary Response capability (between 30 seconds and 30 minutes) 'of a Generating Module or a Energy Storage Unit of type B'. High Frequency Response of a Power Park Module or an Energy Storage Unit is the decrease in output 'immediately after the start of the ramp of the frequency increase' (CCA.3.4.5); the GSO Control Centre may additionally request Energy Storage Units to start a charging cycle depending on State of Charge (CCA.3.4.5, CCA.3.2.4). Response capability must be fully restored no later than 20 minutes after the initial frequency change (CCA.3.5.1). Modal: 'should response no less than' (sic, as printed). Scope note: the >0.5 Hz limb comes from CCA.3.3.1(b), which is cited but not included in the quoted text above; the quote covers limb (a). | Connection Code Appendix 3, CCA.3.3.1(a) Low Frequency response, Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 + Connection Code CC.6.4.4.7, Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 |
The clauses this row citesConnection Code Appendix 3, CCA.3.3.1(a) Low Frequency response, Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ For low frequency deviations of 0.5Hz or lesser, each Generating Module of this type should response no less than 2% of 0.1Hz change or to the Registered Capacity. For example, if the Frequency deviation is 0.5 Hz, the corresponding minimum frequency response requirement is 10% of the Registered Capacity. ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) Connection Code CC.6.4.4.7, Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ Each Generating Unit and/or Generating Module or Energy Storage Unit must be able to meet the minimum frequency response requirement profile subject to and in accordance with the provisions of Appendix 3 ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) | ||
| Frequency bands 47–52 Hz with durations Continuous operating range | Design envelope 47–52 Hz: 49.5–50.5 Hz continuous; 48.5–49.5 Hz, 47.5–48.5 Hz and 50.5–51.5 Hz each 90 minutes; 51.5–52 Hz 60 minutes; 47–47.5 Hz 10 seconds (per event) CC.6.2.3.2 binds the design of 'User's Plant and Apparatus' (all Users, storage included via the User definition); CC.6.4.9.1 restates it as an operating obligation naming each Generating Module or Energy Storage Unit explicitly. Durations apply 'for each event occurring on the Grid System'. Nominal frequency 50 Hz, controlled within 49.5–50.5 Hz unless exceptional circumstances prevail (CC.6.2.3.1). Companion under/over-frequency relay settings: trip at 47.0 Hz, or sustained ≤47.5 Hz for at least 10 seconds, or sustained above 52 Hz (CC.6.4.9.2). System voltage bands at CC.6.2.4.1: normal ±5% (500 kV), +10%/−5% (275 kV), ±10% (132 kV); abnormal ±10% at all three levels, with the +5% to +10% high-voltage band lasting no longer than 15 minutes. | Connection Code CC.6.2.3.2 frequency range table, Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 + Connection Code CC.6.4.9.1, Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 |
The clauses this row citesConnection Code CC.6.2.3.2 frequency range table, Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ Frequency Range | Required Duration | 51.5 – 52 Hz | 60 minutes | 50.5 – 51.5 Hz | 90 minutes | 49.5 – 50.5 Hz | continuous | 48.5 – 49.5 Hz | 90 minutes | 47.5 – 48.5 Hz | 90 minutes | 47. – 47.5 Hz | 10 seconds ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) Connection Code CC.6.4.9.1, Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ As stated in CC6.2.3.2, the System Frequency could rise to 52Hz or fall to 47Hz. Each Generating Module or Energy Storage Unit must continue to operate within this Frequency range for at least the periods of time given in CC6.2.3.2. ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) | ||
| Ramp rate — no numeric code limit Ramp rate | No numeric active-power ramp-rate limit is printed in the code; the GSO specifies Dispatch Ramp Rate requirements per plant for incorporation in the relevant Agreement at connection application CC.6.4.12.1 names 'Generating Unit' only — Energy Storage Units are not expressly named in this clause, so storage applicability of the Dispatch Ramp Rate mechanism is unclear (via generation-scoped drafting; ESUs are elsewhere treated as dispatchable units: SDC2.4.4 defines the scope of Dispatch Instructions for Energy Storage Operators, and availability declarations register loading and de-loading ramp rates as plant data). No separate charge-mode vs discharge-mode ramp limits are printed anywhere in the code. The 'Loading and de-loading ramp rates' text sits at DRC.8.1.5 (p.358), and the DRC's four explicit MW/min registration fields (p.316) are declared plant data, not an imposed limit. | Connection Code CC.6.4.12.1 (CC.6.4.12 Dispatch Ramp Rate), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 |
The clause this row citesConnection Code CC.6.4.12.1 (CC.6.4.12 Dispatch Ramp Rate), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ The GSO shall specify the requirements for Generating Unit Dispatch Ramp Rate in consultation with the Generator for suitable incorporation in the relevant Agreements by the Single Buyer at the time of a connection application. ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) | ||
| RoCoF withstand 2 Hz/s (500 ms) RoCoF withstand | Remain synchronized for RoCoF up to and including 2 Hz/s, measured over a rolling 500 millisecond period; auxiliaries must remain in operation Binds each Generating Module and Energy Storage Unit explicitly (clause names Energy Storage Units directly; sits in CC.6.3, requirements for User's equipment at the Connection Point). The GSO may review the required RoCoF value based on network studies (CC.6.3.4.9). | Connection Code CC.6.3.4.8, Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 |
The clause this row citesConnection Code CC.6.3.4.8, Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ Each Generating Module and Energy Storage Unit must remain synchronized to the Grid System in case the ROCOF remains below or equal to 2 Hz/s, measured over a rolling 500 millisecond period. In addition, the auxiliaries of the Generating Modules and the Energy Storage Unit must remain in operation for avoiding the tripping of the Generating Modules or Energy Storage Unit ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) | ||
| Reactive current via settable FRT droop Fault-current injection | No fixed reactive-current gain k or response time: during voltage dips the quantum of reactive current shall be based on settable FRT droop and P/Q priority values, injected when Connection Point voltage is outside CC6.2.4.1 limits, within transient rating limits; Active Power at least in proportion to retained voltage Binds each Generating Module or Energy Storage Unit and/or any constituent (Energy Storage Units named in the FRT clause CC.6.4.15.2, which storage is expressly subject to). Applies during voltage dips within the FRT curves lasting greater than 300 ms; measured at the Connection Point. Negative-sequence current treatment is not specified. After fault clearance, Active Power output shall be restored immediately to at least 90% of the pre-fault level (CC.6.4.15.2 body text). The clause leaves both the FRT droop and the priority between active and reactive current as settable values, with no code-printed defaults. | Connection Code CC.6.4.15.2(b), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 |
The clause this row citesConnection Code CC.6.4.15.2(b), Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025 — “ provide Active Power output at the Connection Point during voltage dips on the Grid System at least in proportion to the retained balanced voltage at the Connection Point (except when there has been a reduction in the Intermittent Power Source) and shall generate reactive current (where the voltage at the Connection Point is outside the limits specified in CC6.2.4.1) without exceeding the transient rating limits of the Generating and any constituent of it. The quantum of reactive current shall be based on settable FRT droop and P/Q priority values. ” (Grid Code for Peninsular Malaysia – Additional Code, KOD/ST/No.9/2025, accessed 2026-08-09) | ||
Who does Malaysia (Grid Code Additional Code 2025) bind, and since when?
PPMs and energy storage units on the Peninsular grid system. 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 Malaysia (Grid Code Additional Code 2025)
- Does Malaysia (Grid Code Additional Code 2025) require ride-through, or only that the plant does not trip?
- Ride-through. Every envelope on this page is a performance duty the plant must meet, not a protection-setting no-trip boundary — they are different obligations. That is what these curves are; they are not everything Malaysia (Grid Code Additional Code 2025) contains. The requirement sentence under each chart says which side of the curve is the compliant one.
- Are the numbers on this page taken from Malaysia (Grid Code Additional Code 2025) 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 Malaysia (Grid Code Additional Code 2025)?
- Malaysia (Grid Code Additional Code 2025) is charted here with 2 envelopes — low-voltage ride-through, frequency ride-through (LVRT, FRT). No high-voltage envelope is charted here — check Malaysia (Grid Code Additional Code 2025) itself before concluding it sets none.
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.
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