Method for controlling power-on or power-off of air conditioner

A method comprising:

• powering on an air conditioner comprising a variable capacity compressor, wherein the variable capacity compressor is configured to be switchable between a single-cylinder mode and a dual-cylinder mode, and wherein powering on the air conditioner comprises:
• before powering on the air conditioner, determining whether the variable capacity compressor is in the single-cylinder mode or the dual-cylinder mode, wherein determining whether the variable capacity compressor is in the single-cylinder mode or the dual-cylinder mode comprises:
• determining whether a last shutdown of the air conditioner is due to a receipt of a power-off signal, and
• responsive to determining that the last shutdown of the air conditioner is due to the receipt of a power-off signal, determining that the air conditioner is in the single-cylinder mode;
• and
• performing at least one of:
• responsive to determining that the variable capacity compressor is in the single-cylinder mode, powering on the air conditioner with the variable capacity compressor in the single-cylinder mode;
• or
• responsive to determining that the variable capacity compressor is in the double-cylinder mode, switching the variable capacity compressor to the single-cylinder mode, and subsequently powering on the air conditioner with the variable capacity compressor in the single-cylinder mode.