1. A vapor compression refrigeration cycle system, comprising: a compressor having first and second refrigerant ports; an electronic expansion valve connected between said first and second refrigerant ports; and an expansion valve controller configured to control a flow of refrigerant through said expansion valve in response to a superheat temperature of said refrigerant, wherein said controller is configured to execute a first control algorithm until a local maximum of the superheat temperature occurs, and then to execute a second control algorithm.