Alternating-current transmission diesel locomotive power supply system

The embodiment of the invention discloses an alternating-current transmission diesel locomotive power supply system. The system comprises a main generator, a first traction power supply unit, a second traction power supply unit, a first traction generator system module, a second traction generator system module, a first isolation transformer, a first alternating/direct current converter, an auxiliary inversion unit, a selective switch, an auxiliary motor module, a charger module and an excitation control module. The system supplies power through an intermediate loop, an auxiliary diesel generating set is omitted, locomotive space is saved, and the weight is reduced; and the auxiliary motor adopts the same frequency, which is convenient for platform design. Thus, alternating-current transmission diesel locomotive power supply system provided by the invention is high in integration level, light in weight and convenient to maintain, so as to enhance the practical applicability of an alternating-current transmission diesel locomotive.