Direct current to alternating current power supply bidirectional system for vehicles or transport containers with an electrical equipment , said electrical equipment being adapted to be supplied by an AC electrical supply, the system comprising: an electrical grid connector for connection to a mains electrical grid; a direct current, DC, energy source ; a bidirectional direct current to alternating current, DC-AC, controller connected to the direct current energy source; and a filter with a series inductance and a parallel capacitance , arranged to be connected between the DC-AC controller and said AC electrical supply, for limiting the DC-AC controller current variation when the system is supplying the electrical equipment; characterized by the system further comprising switches which are bidirectional and independently switchable; and the system further comprising an electronic data processor configured for switching said switches between operating modes which comprise: supplying the electrical equipment with the AC electrical supply from the DC energy source through the DC-AC controller and the filter; charging the DC energy source from the mains electrical grid via the electrical grid connector; injecting energy from the DC energy source into the mains electrical grid via the electrical grid connector; supplying the electrical equipment directly from the mains electrical grid via the electrical grid connector; and simultaneously, supplying the electrical equipment directly from the mains electrical grid via the electrical grid connector while the DC energy source charges with power derating by the DC-AC controller. an electrical grid connector for connection to a mains electrical grid; a direct current, DC, energy source ; a bidirectional direct current to alternating current, DC-AC, controller connected to the direct current energy source; and a filter with a series inductance and a parallel capacitance , arranged to be connected between the DC-AC controller and said AC electrical supply, for limiting the DC-AC controller current variation when the system is supplying the electrical equipment; characterized by the system further comprising switches which are bidirectional and independently switchable; and the system further comprising an electronic data processor configured for switching said switches between operating modes which comprise: supplying the electrical equipment with the AC electrical supply from the DC energy source through the DC-AC controller and the filter; charging the DC energy source from the mains electrical grid via the electrical grid connector; injecting energy from the DC energy source into the mains electrical grid via the electrical grid connector; supplying the electrical equipment directly from the mains electrical grid via the electrical grid connector; and simultaneously, supplying the electrical equipment directly from the mains electrical grid via the electrical grid connector while the DC energy source charges with power derating by the DC-AC controller. supplying the electrical equipment with the AC electrical supply from the DC energy source through the DC-AC controller and the filter; charging the DC energy source from the mains electrical grid via the electrical grid connector; injecting energy from the DC energy source into the mains electrical grid via the electrical grid connector; supplying the electrical equipment directly from the mains electrical grid via the electrical grid connector; and simultaneously, supplying the electrical equipment directly from the mains electrical grid via the electrical grid connector while the DC energy source charges with power derating by the DC-AC controller. <EOS>