# US 10,502,788 B2 · Circuit for driving 3-phase motor

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- Number: US 10,502,788 B2
- Document ID: US10502788B2
- Status: Granted
- Kind: B2
- Application number: 15/869,382
- Filed: 2018-01-12
- Published: 2018-07-19
- Granted: 2019-12-10
- Earliest claimed: 2017-01-18
- Assignees: Hyundai Mobis Co., Ltd.
- Applicants: Hyundai Mobis Co., Ltd.
- Inventors: Jaehyun Park
- Web page: https://patentgrep.com/patent/US10502788B2

## CPC

- G01R 31/34: Testing dynamo-electric machines
- G01R 31/42: AC power supplies
- H02P 29/0241: {the fault being an overvoltage}
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS

## Abstract

A circuit for driving a 3-phase motor including: an inverter circuit configured to drive a 3-phase motor; a power supply configured to supply an inverter driving voltage and an inverter fault detection voltage to the inverter circuit; and a controller configured to select a voltage supplied by the power supply to the inverter circuit, depending on whether the 3-phase motor is driven. The controller then determines a fault state of the inverter circuit by periodically detecting voltage levels of designated nodes of the inverter circuit.

## Claims

### Claim 1

A circuit for driving a 3-phase motor, comprising:
an inverter circuit configured to drive a 3-phase motor;
a power supply configured to supply an inverter driving voltage and an inverter fault detection voltage to the inverter circuit; and
a controller configured to select a voltage supplied by the power supply to the inverter circuit, depending on whether the 3-phase motor is driven,
wherein:
the controller is configured to determine a fault state of the inverter circuit by periodically detecting voltage levels of a plurality of designated nodes of the inverter circuit;
the controller is configured to:
apply the inverter driving voltage to the inverter circuit when the 3-phase motor is driven; and
apply the inverter fault detection voltage to the inverter circuit when the 3-phase motor is not driven;
detect voltages at the designated nodes of the inverter circuit for driving the 3-phase motor;
compare the detected voltages to voltages stored in a lookup table; and
determine states of the respective switch elements in the inverter circuit
depending on the detected voltages; and
the voltages detected at the designated nodes for the voltages applied to the respective switch elements of the inverter circuit, depending on a normal state or fault state, are stored in the form of a lookup table in advance.

### Claim 2 (depends on 1)

The circuit of claim 1, wherein the controller is configured to detect:
a voltage level of a node through which first terminals of high-level switch elements of the inverter circuit are commonly connected to an output terminal of the power supply; and
voltage levels of nodes to which second terminals of the high-level switch elements and first terminals of low-level switch elements are commonly connected, respectively,
wherein the second terminals of the high-level switch elements and the first terminals of the low-level switch elements are connected to the respective phases of the 3-phase motor.

### Claim 3 (depends on 2)

The circuit of claim 2, wherein the inverter circuit comprises three high-level switch elements and three low-level switch elements which are connected in series to each other, respectively.

### Claim 4 (depends on 3)

The circuit of claim 3, wherein the first terminals of the high-level switch elements are connected to the output terminal of the power supply, the second terminals of the high-level switch elements are connected to the respective phases of the 3-phase motor, the first terminals of the low-level switch elements are connected to the respective phases of the 3-phase motor, the second terminals of the low-level switch elements are grounded, and resistors are connected in parallel with the respective switch elements.

### Claim 5 (depends on 4)

The circuit of claim 4, wherein the resistors are configured in such a manner that the sums of values of resistor pairs each connected to each other are different from each other.

### Claim 6 (depends on 1)

The circuit of claim 1, wherein the power supply comprises:
a first power supply configured to supply the inverter driving voltage to the inverter circuit through switching of first and second FETs; and
a second power supply configured to supply the inverter fault detection voltage to the inverter circuit through switching of first and second transistors.

### Claim 7 (depends on 6)

The circuit of claim 6, wherein:
the inverter driving voltage is supplied for the inverter circuit to drive the 3-phase motor; and
the inverter fault detection voltage is supplied to periodically determine whether each of the switch elements of the inverter circuit has a fault or damage, when the 3-phase motor is not driven.