A system comprising a synchronous machine and a thyristor starter for starting the synchronous machine, wherein the thyristor starter comprises: a converter that converts AC power into DC power; a DC reactor that smoothes the DC power; an inverter that converts the DC power applied from the converter through the DC reactor into AC power with a variable frequency and supplies the AC power to the synchronous machine; a position detector that detects a rotor position of the synchronous machine; a first controller that controls a firing phase of a thyristor in the inverter, based on a detection signal of the position detector; and a second controller that controls a firing phase of a thyristor in the converter such that a maximum value of DC output current of the converter matches a current command value, based on a detection signal of the position detector, wherein the thyristor starter accelerates the synchronous machine from a stop state to a predetermined rotation speed by sequentially performing a first mode and a second mode, the first mode of performing commutation of the inverter by intermittently setting the DC output current to zero, the second mode performing commutation of the inverter by induced voltage of the synchronous machine, wherein the synchronous machine includes: a stator receiving supply of the AC power supplied from the inverter; a rotor; characterized in that the synchronous machine further includes: a fan that is attached to a rotation shaft of the rotor, the fan circulating a cooling medium through a passage formed in the rotor and the stator, wherein in the first mode, the current command value is set in accordance with the rotation speed of the synchronous machine such that a current value is larger as rotation speed of the synchronous machine is higher and the current command value at a first rotation speed lower than a prescribed rotation speed is smaller than the current command value at a second rotation speed higher than the prescribed rotation speed, the prescribed rotation speed being set based on a lower limit rotation speed of the fan at which the cooling medium can be circulated through the passage. a converter that converts AC power into DC power; a DC reactor that smoothes the DC power; an inverter that converts the DC power applied from the converter through the DC reactor into AC power with a variable frequency and supplies the AC power to the synchronous machine; a position detector that detects a rotor position of the synchronous machine; a first controller that controls a firing phase of a thyristor in the inverter, based on a detection signal of the position detector; and a second controller that controls a firing phase of a thyristor in the converter such that a maximum value of DC output current of the converter matches a current command value, based on a detection signal of the position detector, wherein the thyristor starter accelerates the synchronous machine from a stop state to a predetermined rotation speed by sequentially performing a first mode and a second mode, the first mode of performing commutation of the inverter by intermittently setting the DC output current to zero, the second mode performing commutation of the inverter by induced voltage of the synchronous machine, wherein the synchronous machine includes: a stator receiving supply of the AC power supplied from the inverter; a rotor; a stator receiving supply of the AC power supplied from the inverter; a rotor; characterized in that the synchronous machine further includes: a fan that is attached to a rotation shaft of the rotor, the fan circulating a cooling medium through a passage formed in the rotor and the stator, wherein in the first mode, the current command value is set in accordance with the rotation speed of the synchronous machine such that a current value is larger as rotation speed of the synchronous machine is higher and the current command value at a first rotation speed lower than a prescribed rotation speed is smaller than the current command value at a second rotation speed higher than the prescribed rotation speed, the prescribed rotation speed being set based on a lower limit rotation speed of the fan at which the cooling medium can be circulated through the passage.