Patent ID: 8018191
Filing Date: 2011-09-13
Classification: B62D,H02P

Abstract:
1. An electric power steering system for generating steering assist force by driving a motor using a main power supply and an auxiliary power supply for auxiliary power as required, the electric power steering system comprising: a first switch including a first switching element provided in a path for supplying power from the main power supply to the motor and a first diode arranged in parallel with the first switching element such that a current flow direction of the first diode coincides with a current flow direction at a power supplying time; a second switch including a second switching element provided in a path for supplying power from the main power supply and the auxiliary power supply to the motor and a second diode arranged in parallel with the second switching element such that a current flow direction of the second diode is opposed to the current flow direction at the power supplying time; a voltage detector which detects a sum voltage (V a rotation speed detector which detects the rotation speed of the motor; and a control and drive unit which computes a voltage V