Variable frequency iteration MPPT for resonant power converters

A resonant power converter, comprising:

• a DC/DC converter section including a plurality of power semiconductor switches having an input for receiving electrical power from a power source,
• a resonant circuit having an input coupled to an output of said DC/DC converter section;
• a processor coupled to control input drivers which are coupled to control inputs of said power semiconductor switches,
• wherein said processor is programmed to implement a MPPT algorithm that includes:
• initializing by setting an initial boundary frequency range, dividing said initial boundary frequency range into a plurality of initial frequency sub-ranges bounded by a plurality of initial frequencies including an initial center frequency and first and second initial bounding frequency that are all within said initial boundary frequency range;
• a first iteration including measuring initial power values at said plurality of initial frequencies to determine which frequency provides a maximum power (maximum power initial frequency), and using said maximum power initial frequency to set a first reduced frequency search range centered or bounded by said maximum power initial frequency including at least a first additional bounding frequency, said first reduced frequency search range narrower as compared to a range of said plurality of initial frequencies,
• at least a second iteration, said second iteration including calculating first and second center frequencies by averaging adjacent frequent values in said first reduced frequency search range and measuring second power values at said first and said second center frequencies, and
• determining a switching frequency for said resonant power converter from measured power values including said second power values.