A composition containing a melt-processing water-free, solvent-free polyacrylate and an anti-oxidizing agent which contains at least one aromatically bonded hydroxyl group and which is exclusively comprised of hydrogen, carbon and oxygen atoms. The system includes a gas turbine engine as a first motive power source, and one or more battery packs as a second motive power source. The over current judgment unit determines whether the resonant current is higher than an over current value according to a current detecting signal generated by the current detecting circuit.