Motor driving device
View Patent ↗Disclosed is a motor driving device for driving a motor having coil sets that includes energization systems each including a drive circuit, the drive circuits being one-to-one connected to the coil sets; first semiconductor switches disposed in the energization systems in a one-to-one correspondence, each first semiconductor switch lying between a power supply and the corresponding one of the drive circuits; and a second semiconductor switch which connects the power supply and each of the first semiconductor switches in series. Each of the first semiconductor switches includes a parasitic diode of which a forward direction is from the corresponding drive circuit to the second semiconductor switch, and the second semiconductor switch includes a parasitic diode of which a forward direction is from the power supply to the first semiconductor switches.
1. A motor driving device for driving a motor having a plurality of coil sets, comprising:
a plurality of energization systems each including a drive circuit, the plurality of drive circuits being one-to-one connected to the plurality of coil sets;
a plurality of first semiconductor switches disposed in the plurality of energization systems in a one-to-one correspondence, each first semiconductor switch lying between a power supply and a corresponding one of the plurality of drive circuits;
a second semiconductor switch which connects the power supply and each of the plurality of first semiconductor switches in series; and
a controller connected to the plurality of drive circuits and the first and second semiconductor switches so as to control the plurality of drive circuits and the first and second semiconductor switches, wherein
each of the plurality of first semiconductor switches includes a parasitic diode of which a forward direction is from a corresponding one of the drive circuits to the second semiconductor switch, and
the second semiconductor switch includes a parasitic diode of which a forward direction is from the power supply to the first semiconductor switches.
2. The motor driving device according to claim 1 , wherein
the controller diagnoses whether or not an abnormality has occurred in the plurality of energization systems, and
when the controller diagnoses that an abnormality has occurred in any of the plurality of energization systems, the controller turns off, among the first semiconductor switches, a first semiconductor switch in the energization system in which the abnormality has occurred.
3. The motor driving device according to claim 1 , wherein the controller turns on the second semiconductor switch when driving the motor.
4. The motor driving device according to claim 1 , wherein
the controller includes separate controllers in the energization systems in a one-to-one correspondence,
each of the separate controllers diagnoses whether or not an abnormality has occurred in a corresponding one of the energization systems, and
when any of the separate controllers diagnoses that an abnormality has occurred in a corresponding one of the energization systems, the separate controller turns off the first semiconductor switch in the energization system.
5. The motor driving device according to claim 4 , wherein
each of the separate controllers outputs a status signal indicating whether a corresponding one of the energization systems is operating normally or abnormally, and
the second semiconductor switch is connected to the separate controllers so as to be controlled based on the status signals.
6. The motor driving device according to claim 5 , further comprising
a logic circuit connected to the separate controllers so as to receive the status signals,
wherein the second semiconductor switch is connected to the logic circuit so as to be controlled based on a logical output from the logic circuit.
7. The motor driving device according to claim 1 , further comprising:
a power supply line extending from the power supply through the second semiconductor switch; and
a plurality of power feed lines branched from the power supply line, each of the plurality of power feed lines extending to a corresponding one of the plurality of energization systems through a corresponding one of the first semiconductor switches, wherein
the power supply line extends through a CL-type low-pass filter, and
each of the plurality of power feed lines extends through a capacitor connected to ground.
8. The motor driving device according to claim 1 , further comprising:
a power supply line extending from the power supply through the second semiconductor switch; and
a plurality of power feed lines branched from the power supply line, each of the plurality of power feed lines extending to a corresponding one of the plurality of energization systems through a corresponding one of the first semiconductor switches, wherein
the power supply line extends through a capacitor connected to ground, and
each of the plurality of power feed lines extends through an LC-type low-pass filter.
9. The motor driving device according to claim 1 , further comprising:
a power supply line extending from the power supply through the second semiconductor switch; and
a plurality of power feed lines branched from the power supply line, each of the plurality of power feed lines extending to a corresponding one of the plurality of energization systems through a corresponding one of the first semiconductor switches,
wherein the power supply line extends through a π-type low pass filter.
10. The motor driving device according to claim 1 , wherein the motor is used to generate a torque corresponding to a steering assist force of an electric power steering system.