The utility model relates to an unbalanced three phase adjustment device and reactive power compensator, reactive power compensator include the cabinet body, the main control circuit board and air -cooled system, the forced air cooling system is including locating respectively cabinet body opposite ends's air intake and air outlet, fan and wind channel, the wind channel intercommunication the air intake with the air outlet, the fan is located the wind channel corresponds the one end of air intake, the main control circuit board locates the cabinet is internal and including the power electronic device, the power electronic device is located in the wind channel. Above -mentioned reactive power compensator's the internal wind channel that is equipped with intercommunication air intake and air outlet of cabinet to the cold wind power electronic device in the wind channel of flowing through under the effect of air intake department fan with hot -blastly flowing out from the air outlet that the power electronic device went on forming after the heat exchange, prevents that the internal radiating air flow of cabinet is disorderly, and airflow flow velocity, radiating efficiency are high, can satisfy reactive power compensator's heat dissipation demand.