Twelve years of operation with the Joint European Torus (JET), the major experiment of the European Union fusion research programme, have allowed studies of tokamak plasmas up to reactor relevant performance and to resolve key physics and engineering issues for the design of the International Tokamak Experimental Reactor (ITER). A key role in the success of JET has been the development of the power conversion system, which supplies the main electrical loads of a tokamak.The JET machine recently underwent a major upgrade with the installation of a pumped divertor for the control of the impurity influx into the plasma.The objective of this paper is to describe the new power supplies required to supply the divertor coils and to control the plasma.