An electrical power supply system, including: at least one virtual air gap transformer, including at least one primary winding, at least one secondary winding, and multiple control windings configured to generate multiple virtual air gaps in order to control the electromagnetic coupling between the primary and secondary windings; an input port configured to receive a first input signal having a time-varying first input fundamental frequency (f in) and a time-varying first input voltage (V in); and a control component configured: to receive at least one signal representing the time-varying first input voltage (V in) and the time-varying first input fundamental frequency (f in) of the first input signal, and to generate a corresponding virtual air gap control signal to determine the electrical current in the control windings of the at least one virtual air gap transformer, such that a target output voltage (V out) of a target output frequency (F out) is generated at the secondary windings, the target output frequency (F out) and the target output voltage (V out) to match energy required by a load on the electrical power supply system; wherein the electrical power supply system is configured to receive input electrical energy in the form of the first input signal having the time-varying first input fundamental frequency (f in) and the time-varying first input voltage (V in), and to generate corresponding output electrical energy in the form of a corresponding first output signal of the target output frequency (Fout) and the target output voltage (V out); and wherein the at least one virtual air gap transformer includes multiple virtual air gaps (208, 210) arranged to selectably define opposing flux paths through the at least one secondary winding. at least one virtual air gap transformer, including at least one primary winding, at least one secondary winding, and multiple control windings configured to generate multiple virtual air gaps in order to control the electromagnetic coupling between the primary and secondary windings; an input port configured to receive a first input signal having a time-varying first input fundamental frequency (f in) and a time-varying first input voltage (V in); and a control component configured: to receive at least one signal representing the time-varying first input voltage (V in) and the time-varying first input fundamental frequency (f in) of the first input signal, and to generate a corresponding virtual air gap control signal to determine the electrical current in the control windings of the at least one virtual air gap transformer, such that a target output voltage (V out) of a target output frequency (F out) is generated at the secondary windings, the target output frequency (F out) and the target output voltage (V out) to match energy required by a load on the electrical power supply system; wherein the electrical power supply system is configured to receive input electrical energy in the form of the first input signal having the time-varying first input fundamental frequency (f in) and the time-varying first input voltage (V in), and to generate corresponding output electrical energy in the form of a corresponding first output signal of the target output frequency (Fout) and the target output voltage (V out); and wherein the at least one virtual air gap transformer includes multiple virtual air gaps (208, 210) arranged to selectably define opposing flux paths through the at least one secondary winding.