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 (34, 33, 61) 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 (34, 33, 61) 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.