An electrical power supply process, including receiving, at a control component of an electrical power supply system a signal representing a time-varying first fundamental frequency and a first voltage of the first input signal; processing the received signal to generate a corresponding frequency control signal to cause a heterodyning component to generate a corresponding heterodyned signal havingfrequency components corresponding to a sum and a difference of the first fundamental frequency and a reference frequency; and a corresponding voltage control signal to cause a virtual air-gap transformer to generate a corresponding signal having a target output voltage whereby the received input electrical energy in the form of the first input signal having the first input fundamental frequencyand the first voltage is processed to generate corresponding output electrical energy in the form of a corresponding first output signal of the target frequency and the target output voltage.