1-1 Abstract
Taipower company adopts the System Average Interruption Duration Index (SAIDI) and the System Average Interruption Frequency Index (SAIFI), which are commonly used in the international power industry. It is in compliance with IEEE 1366 std and the World Bank for SAIDI and SAIFI measures basic conditions.
- SAIDI (min / household•year)
The System Average Interruption Duration Index (SAIDI) indicates the total duration of interruption for the average customer during a predefined period of time. It is commonly measured in minutes or hours of interruption. - SAIFI (times / household•year)
The System Average Interruption Frequency Index (SAIFI) indicates how often the average customer experiences a sustained interruption over a predefined period of time.
1-2 The Components of Power Supply Reliability
- Planned Outage
In recent years, the actual planned outage time accounts for about 70%~76% of the company’s average power outage time. - Forced outage
In recent years, no warning accidents, force outages time accounts for about 24%~30% of the Taipower’s average power outage time.
1-3 Conclusion
- The Statistics for Power Outage Time (which is) more than 1 minute
If the customer interruptions is more than 1 minute, it will be counted in the statistics for SAIDI & SAIFI in Taipower company； however, if the time of customer interruption is more than 5 or 3 minutes, that will be counted in the statistics in most power companies. Thus, the requirements for reliability in Taipower is more stringent for current power companies standard.
*1：A major power outage occurred on August 15, 2017. The main reason was the gas supply interruption of CPC Corporation, Taiwan. The SAIDI and SAIFI values caused by this accident were 32.572 (
mins/household.year) and 0.553 (times/household.year) respectively
*2：A major power outage occurred on May 13 and May 17, 2021. The SAIDI and SAIFI values caused by this accident were 43.516 (mins/household.year) and 0.864 (times/household.year) respectively.
*3：A major power outage occurred on March 3, 2022. The SAIDI and SAIFI values caused by this accident were 91.285 (mins/household.year) and 0.467 (times/household.year) respectively.