Abstract: To provide a motor driver and a motor driving system which allow a reduction in power consumption of a heat exchanger provided in a power magnetics cabinet while keeping down manufacturing cost. A motor driver is accommodated in a power magnetics cabinet and drives a motor. The motor driver comprises: a storage unit that stores the quantity of heat generated independently of the value of a current I[Arms] caused to flow in the motor as a generated heat quantity a[W]; a current detection unit that detects the value of the current I[Arms] caused to flow in the motor; and a heat quantity calculation unit that calculates the quantity of heat P[W] released to the interior of the power magnetics cabinet by adding the heat quantity a[W] stored in the storage unit and a heat quantity q×K[W/Arms]×I[Arms] responsive to the value I[Arms] detected by the current detection unit.

Abstract: To provide a motor driver and a motor driving system which allow a reduction in power consumption of a heat exchanger provided in a power magnetics cabinet while keeping down manufacturing cost. A motor driver is accommodated in a power magnetics cabinet and drives a motor. The motor driver comprises: a storage unit that stores the quantity of heat generated independently of the value of a current I[Arms] caused to flow in the motor as a generated heat quantity a[W]; a current detection unit that detects the value of the current I[Arms] caused to flow in the motor; and a heat quantity calculation unit that calculates the quantity of heat P[W] released to the interior of the power magnetics cabinet by adding the heat quantity a[W] stored in the storage unit and a heat quantity q×K[W/Arms]×I[Arms] responsive to the value I[Arms] detected by the current detection unit.