Abstract: Methods, systems, and devices for phase balancing of a plurality of high frequency (HF) power generation units of an HF power supply system. In one aspect, a method includes measuring a first signal related to a first power reflected at a load and arriving at a first HF power generation unit, obtaining at least one first value related to the measured first signal in a system control, adjusting at least one of a frequency or a phase of an output signal of the first HF power generation unit based on the at least one first value and a reference value, measuring a second signal related to a second power reflected at the load and arriving at the first HF power generation unit, obtaining at least one second value related to the measured second signal in the system control, and determining whether a specified event for the first HF power generation unit occurs. The method also includes performing phase balancing of one or more further HF power generation units.