Canada (Alberta AESO) — ride-through requirements

The LVRT, HVRT, FRT envelopes a grid-scale battery must meet under Canada (Alberta AESO), digitized breakpoint by breakpoint and checked against the clause it came from.

By Sergey Syrvachev — Director of Product Engineering at HyperStrong

Applies to: transmission connections — Generating facilities on the Alberta transmission system (AIES).

Part of: the grid-code ride-through chart — compare this against 65 other standards in 44 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. These are the boundaries, not the behaviour: what holding one demands of the converter — reactive current injection, thermal stress, protection timing — is stepped through in the LVRT / HVRT ride-through visual.

EventDutyBreakpointsStatus
low-voltage ride-through (LVRT)ride-through0.001s → 0 pu; 0.15s → 0 pu; 0.151s → 0.45 pu; 0.3s → 0.45 pu; 0.301s → 0.65 pu; 2s → 0.65 pu; 2.001s → 0.75 pu; 3s → 0.75 pu; 3.001s → 0.9 puverified
high-voltage ride-through (HVRT)ride-through0.001s → 1.2 pu; 0.2s → 1.2 pu; 0.201s → 1.175 pu; 0.5s → 1.175 pu; 0.501s → 1.15 pu; 1s → 1.15 pu; 1.001s → 1.1 puverified
frequency ride-through (FRT)ride-throughHigh: 0.1s → 61.7 Hz; 30s → 61.7 Hz; 30.001s → 61.6 Hz; 180s → 61.6 Hz; 180.001s → 60.6 Hz | Low: 0.1s → 57 Hz; 0.75s → 57 Hz; 0.751s → 57.3 Hz; 7.5s → 57.3 Hz; 7.501s → 57.8 Hz; 30s → 57.8 Hz; 30.001s → 58.4 Hz; 180s → 58.4 Hz; 180.001s → 59.4 Hzverified

Where these values come from

  • LVRTAESO ISO Rules Section 503.5 Voltage Ride-Through, Appendix 1 'Voltage Ride-Through Requirements', Low Voltage Ride-Through Duration table: '< 0.45 / 4 to 9 cycles', '< 0.65 / 0.30 seconds', '< 0.75 / 2.00 seconds', '< 0.90 / 3.00 seconds', '>= 0.90 / Continuous operation'; plus subsection 2(2)(c). Effective 2024-04-01.
  • HVRTAESO ISO Rules Section 503.5, Appendix 1, High Voltage Ride-Through Duration table: '>= 1.200 / Instantaneous trip', '>= 1.175 / 0.20 seconds', '>= 1.15 / 0.50 seconds', '>= 1.10 / 1.00 seconds', '< 1.10 / Continuous operation'. Also subsection 2(2)(a): continuous operation between 0.90 and 1.10 pu. Effective 2024-04-01.
  • FRTAESO ISO Rules Section 503.6, Appendix 1 'Trip Settings for Off-Nominal Frequency Protective Relays': High - '>=61.7 Instantaneous trip', '>=61.6 / 30', '>=60.6 / 180', '<60.6 Continuous operation'; Low - '<=57.0 Instantaneous trip', '<=57.3 / 0.75', '<=57.8 / 7.5', '<=58.4 / 30', '<=59.4 / 180', '>59.4 Continuous operation'. Contrast IESO Market Rules Appendix 4.2 Issue 16.0 category 1 'Off-Nominal Frequency Operation'.

Read it yourself: AESO ISO Rules Section 503.5 (PDF) ↗

Last checked against the source document on .

How Canada compares

Each event this code defines, put side by side with every other code that defines it:

Other grid codes in North America