Smoke detection control circuit and control method for air conditioning unit of railway vehicle

The invention discloses a smoke detection control circuit for a railway vehicle air conditioning unit, which belongs to the technical field of railway vehicle air conditioning systems, comprises a controller and a plurality of smoke detectors, and is characterized by further comprising a smoke reset relay and an external reset switch, a control coil in the smoke reset relay and the external reset switch are connected in series between the positive electrode and the negative electrode of a direct current 74V power supply; a reset output signal line of the controller to the smoke detector is connected between the external reset switch and the control coil in the smoke reset relay; and two ends of a normally closed contact in the smoke reset relay are respectively connected with the positive electrode of the direct-current 24V power supply and the positive electrodes of the power supply terminals of all the smoke detectors. In addition, the invention further discloses a control method. According to the scheme of