Voltage Reduction Testing

Province-wide system voltage reduction tests are normally conducted every 18 months as per Market Manual 7.1: System Operating Procedures. Tests of voltage reduction procedures are not simulations. Actual voltage reductions are implemented in order to:

• Establish and record the load reduction resulting from a system voltage reduction of 3% and 5%;
• identify any market participant equipment problems due to reduced voltage so that corrective action may be taken;
• measure the total amount of load reduction that is attainable;
• measure the relationship between the magnitude of the voltage reduction and the amount of the load reduction; and
• keep IESO and Market Participant staff familiar with procedures and identify any deficiencies in the procedures so they can be corrected as required.

Note that additional local or province-wide tests may be scheduled if the IESO and the affected market participants so agree (Chapter 5, Section 11.7.5 of the market rules). Voltage reductions have minimal or no noticeable impact on the public at large.

Voltage Reduction Test Reports

• Voltage Reduction Test - January 22, 2009
• Voltage Reduction Test - January 19, 2006
• Voltage Reduction Test - July 20, 2004
• Voltage Reduction Test - January 23, 2003