A substation is disclosed for use in a power transmission and distribution network. The substation comprises a single phase isolating high frequency transformer having at least one input winding and at least one output winding with corresponding input and output solid state switching networks. Each input solid state switching network comprises a plurality of semiconductor switching devices which receive an input waveform from the transmission network and output a high frequency waveform to the primary winding of the transformer. Likewise, each output solid state switching network comprises a plurality of semiconductor switching devices receiving a high frequency waveform from the secondary winding of the transformer and outputting an output frequency waveform from the substation. A control circuit is adapted to control the operation of the switching devices of the input and output switching networks to generate the output waveform from the input waveform.