Air conditioner and driving device

Patent metadata

Field	Value
Publication number	US-11863099-B2
Application number	US-201616334834-A
Country	US
Kind code	B2
Filing date	Oct 31, 2016
Priority date	Oct 31, 2016
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

An air conditioner includes a compressor to compress a refrigerant used in a refrigeration cycle, a converter to generate a DC voltage, an inverter to generate three-phase AC voltages from the DC voltage, a motor to produce a driving force for driving the compressor with a plurality of coils, the three-phase AC voltages being applied to the coils, a connection switching unit to switch connection states of the coils between a first connection state and a second connection state, and a controller to detect an abnormality of the connection switching unit.

First claim

The invention claimed is:

1. An air conditioner using a refrigeration cycle, the air conditioner comprising:
a compressor to compress a refrigerant used in the refrigeration cycle;
a fan to blow air to a heat exchanger;
a converter to generate a DC voltage;
an inverter to generate three-phase AC voltages from the DC voltage;
a motor to produce a driving force for driving the compressor with a plurality of coils, the three-phase AC voltages being applied to the coils;
a connection switching unit to switch connection states of the coils between a first connection state and a second connection state;
a current detection circuit to detect a current value of a current on an input side of the inverter, and
a controller to detect an abnormality of the connection switching unit,
wherein the abnormality is opening failure or short-circuit failure,
wherein the controller detects the abnormality of the connection switching unit, based on the current value,
wherein
the connection switching unit sets the connection states of the coils to one of the first connection state and the second connection state,
the inverter is connected to the motor with a first line, a second line, and a third line,
the inverter individually applies a voltage in order to a combination of the first line and the second line, a combination of the second line and the third line, and a combination of the third line and the first line,
the current detection circuit
detects, as a first current value, a current value of the current on the input side of the inverter when the inverter applies the voltage to only the first line and the second line,
detects, as a second current value, a current value of the current on the input side of the inverter when the inverter applies the voltage to only the second line and the third line, and
detects, as a third current value, a current value of the current on the input side of the inverter when the inverter applies the voltage to only the third line and the first line, and
the controller detects the abnormality of the connection switching unit by comparing the first current value, the second current value, and the third current value to each other,
wherein, after the air conditioner receives an input to start an operation of the air conditioner, the fan is driven, and after the fan is driven and before the compressor is driven, the controller detects the abnormality of the connection switching unit.

2. The air conditioner according to claim 1 , wherein
the fan is used in an outdoor unit; and
the fan is driven after receiving the input to start, and after the fan is driven and before the compressor is driven, the controller detects the abnormality of the connection switching unit.

3. The air conditioner according to claim 1 , further comprising an input reception unit to receive input to start an operation of the air conditioner,
wherein the controller detects the abnormality of the connection switching unit in response to reception of the input by the input reception unit.

4. The air conditioner according to claim 3 , wherein
the fan is used in an indoor unit; and
the controller detects the abnormality of the connection switching unit before the fan is driven after the input reception unit receives the input.

5. The air conditioner according to claim 1 , wherein the controller determines that the connection switching unit has the abnormality when at least one of the first current value, the second current value, and the third current value is different from another one of the first current value, the second current value, and the third current value, or when at least one of the first current value, the second current value, and the third current value is not detected.

6. The air conditioner according to claim 5 , wherein the controller determines that at least one of the first current value, the second current value, and the third current value is different from another one of the first current value, the second current value, and the third current value if any absolute value of difference of each pair of the first current value, the second current value, and the third current value is larger than a predetermined threshold.

7. The air conditioner according to claim 1 , wherein
the connection switching unit sets the connection states of the coils to another of the first connection state and the second connection state after the current detection circuit detects the first current value, the second current value, and the third current value,
the inverter individually applies a voltage in order to a combination of the first line and the second line, a combination of the second line and the third line, and a combination of the third line and the first line,
the current detection circuit
detects, as a fourth current value, a current value of the current on the input side of the inverter when the inverter applies the voltage to only the first line and the second line,
detects, as a fifth current value, a current value of the current on the input side of the inverter when the inverter applies the voltage to only the second line and the third line, and
detects, as a sixth current value, a current value of the current on the input side of the inverter when the inverter applies the voltage to only the third line and the first line, and
the controller detects the abnormality of the connection switching unit by comparing the fourth current value, the fifth current value, and the sixth current value.

8. The air conditioner according to claim 1 , wherein
the coils are a first coil having one end connected to the first line, a second coil having one end connected to the second line, and a third coil having one end connected to the third line,
the connection switching unit has
a first switch to switch a connection destination of another end of the first coil;
a second switch to switch a connection destination of another end of the second coil; and
a third switch to switch a connection destination of another end of the third coil, and
the first switch, the second switch, and the third switch individually switch the connection destinations in accordance with an instruction from the controller.

9. The air conditioner according to claim 8 , wherein the first switch, the second switch, and the third switch are semiconductor switches.

10. The air conditioner according to claim 9 , wherein the semiconductor switches are switching elements made by using a WBG semiconductor.

11. An air conditioner using a refrigeration cycle, the air conditioner comprising:
a compressor to compress a refrigerant used in the refrigeration cycle;
a fan to blow air to a heat exchanger;
a converter to generate a DC voltage;
an inverter to generate three-phase AC voltages from the DC voltage;
a motor to produce a driving force for driving the compressor with a plurality of coils, the three-phase AC voltages being applied to the coils;
a connection switching unit to switch connection states of the coils between a first connection state and a second connection state;
a current detection circuit to detect a current value of a current on an input side of the inverter, and
a controller to detect an abnormality of the connection switching unit,
wherein the abnormality is opening failure or short-circuit failure,
wherein the controller detects the abnormality of the connection switching unit, based on the current value,
wherein
the connection switching unit sets the connection states of the coils to one of the first connection state and the second connection state,
the inverter is connected to the motor with a first line, a second line, and a third line,
the inverter applies a voltag

Assignees

• Mitsubishi Electric Corp

Inventors

• Yamakawa Takashi
• Arisawa Koichi
• Iwazaki Kenji
• Uemura Keisuke
• Toyodome Shinya

Classifications

• H02P29/024 Primary

  Detecting a fault condition, e.g. short circuit, locked rotor, open circuit or loss of load · CPC title

• F24F11/88

  Electrical aspects, e.g. circuits · CPC title

• H01H9/563

  for multipolar switches, e.g. different timing for different phases, selecting phase with first zero-crossing · CPC title

• H02P25/18 Primary

  with arrangements for switching the windings, e.g. with mechanical switches or relays · CPC title

• H02P21/02

  specially adapted for optimising the efficiency at low load · CPC title