Detection apparatus, power conditioner, detection method, and computer readable medium

A detection method, wherein

• a detection apparatus calculates frequency parameters according to frequencies of power supplied by a power supply,
• the detection apparatus calculates a deviation parameter according to a frequency deviation based on the frequency parameters in a first term and the frequency parameters in a second term earlier than the first term,
• the detection apparatus detects whether the power supply is in an islanding operation based on the deviation parameter, and
• the detection apparatus changes a time gap between the first term and the second term.

A computer-readable medium recording a detection program to be executed by a computer, wherein

• the detection program is configured to cause the computer to serve as:
• a frequency parameter calculation unit for calculating frequency parameters according to frequencies of power supplied by a power supply;
• a deviation parameter calculation unit for calculating a deviation parameter according to a frequency deviation based on the frequency parameters in a first term and the frequency parameters in a second term earlier than the first term;
• an islanding operation detection unit for detecting whether the power supply is in an islanding operation based on the deviation parameter;
• and
• a time gap change unit for changing a time gap between the first term and the second term.