Refrigeration cycle device
View Patent ↗The refrigerator cycle device includes a control device controlling a compressor including a sealed container constituting a fluidic pathway for a working medium containing ethylene-based fluoroolefin as a refrigerant component, and a compression mechanism and an electric motor inside the sealed container. The control device includes a drive circuit and a control circuit. The drive circuit includes a converter circuit including a first output point outputting a first voltage, a second output point outputting a second voltage lower than the first voltage, and a third output point outputting a third voltage between the first voltage and the second voltage; and an inverter circuit including first to third semiconductor switching element groups connected between the first to third output points and the electric motor. The control circuit performs PWM control on the first to third semiconductor switching element groups to allow the drive circuit to operate the electric motor.
1 . A refrigeration cycle device comprising:
a refrigeration cycle circuit including a compressor, a condenser, an expansion valve and an evaporator, and allowing circulation of a working medium; and
a control device configured to control the compressor of the refrigeration cycle circuit,
the working medium containing ethylene-based fluoroolefin as a refrigerant component,
the compressor including
a sealed container constituting a fluidic pathway for the working medium,
a compression mechanism positioned inside the sealed container to compress the working medium, and
an electric motor positioned inside the sealed container to operate the compression mechanism,
the control device including
a drive circuit configured to drive the electric motor, and
a control circuit configured to control the drive circuit,
the drive circuit including
a converter circuit including a plurality of output points including a first output point for outputting a first voltage, a second output point for outputting a second voltage lower than the first voltage, and one or more third output points for outputting a third voltage between the first voltage and the second voltage, and
an inverter circuit including a plurality of semiconductor switching element groups including a first semiconductor switching element group connected between the first output point and the electric motor, a second semiconductor switching element group connected between the second output point and the electric motor, and one or more third semiconductor switching element groups individually connected between the one or more third output points and the electric motor,
the converter circuit being disposed between a power supply and the inverter circuit, the inverter circuit being disposed between the converter circuit and the electric motor, the converter circuit being configured to convert a first alternating current power to a direct current power, and the inverter circuit being configured to supply a second alternating current power to the electric motor based on the direct current power, and
the control circuit being configured to perform PWM control on the plurality of semiconductor switching element groups of the inverter circuit of the drive circuit to allow the drive circuit to operate the electric motor.
2 . The refrigeration cycle device according to claim 1 , wherein the control circuit is configured to switch between a first state in which the first semiconductor switching element group is on to connect the first output point to the electric motor and a second state in which the second semiconductor switching element group is on to connect the second output point to the electric motor, by way of a third state in which the one or more third semiconductor switching element groups are on to connect the one or more third output points to the electric motor.
3 . The refrigeration cycle device according to claim 1 , wherein
the ethylene-based fluoroolefin contains ethylene-based fluoroolefin likely to undergo a disproportionation reaction.
4 . The refrigeration cycle device according to claim 1 , wherein
the ethylene-based fluoroolefin is 1,1,2-trifluoroethylene, trans-1,2-difluoroethylene, cis-1,2-difluoroethylene, 1,1-difluoroethylene, tetrafluoroethylene, or monofluoroethylene.
5 . The refrigeration cycle device according to claim 1 , wherein
the working medium contains difluoromethane as the refrigerant component.
6 . The refrigeration cycle device according to claim 1 , wherein
the working medium further contains a saturated hydrocarbon.
7 . The refrigeration cycle device according to claim 6 , wherein
the saturated hydrocarbon contains n-propane.
8 . The refrigeration cycle device according to claim 1 , wherein
the working medium contains a haloalkane with 1 or 2 carbon atoms as a disproportionation inhibitor for suppressing a disproportionation reaction of the ethylene-based fluoroolefin.
9 . The refrigeration cycle device according to claim 1 , wherein
the inverter circuit includes a first set of switching elements constituting a first series circuit connected between the first output point and the second output point.
10 . The refrigeration cycle device according to claim 9 , wherein in a first state, the control circuit is configured to turn on a first group of the first set of switching elements,
in a second state, the control circuit is configured to turn on a second group of the first set of switching elements, and
in a third state, the control circuit is configured to turn on a third group of the first set of switching elements.
11 . The refrigeration cycle device according to claim 10 , wherein the inverter circuit further includes a second set of switching elements constituting a second series circuit connected between the first output point and the second output point.
12 . The refrigeration cycle device according to claim 11 , wherein in the first state, the control circuit is configured to turn on a first group of the second set of switching elements,
in the second state, the control circuit is configured to turn on a second group of the second set of switching elements, and
in the third state, the control circuit is configured to turn on a third group of the second set of switching elements.
13 . The refrigeration cycle device according to claim 1 , wherein the converter circuit includes a rectification circuit and a smoothing circuit.
14 . A refrigeration cycle device comprising:
a refrigeration cycle circuit including a compressor, a condenser, an expansion valve and an evaporator, and allowing circulation of a working medium; and
a control device configured to control the compressor of the refrigeration cycle circuit,
the working medium containing ethylene-based fluoroolefin as a refrigerant component,
the compressor including
a sealed container constituting a fluidic pathway for the working medium,
a compression mechanism positioned inside the sealed container to compress the working medium, and
an electric motor positioned inside the sealed container to operate the compression mechanism,
the control device including
a multi-level inverter configured to drive the electric motor, and
a control circuit configured to perform PWM control on the multi-level inverter,
wherein the multi-level inverter includes multiple output points for outputting multiple voltages, the multiple voltages are different from each other, the multi-level inverter further includes an electrical component connected between the multiple output points and corresponding input terminals of the electric motor,
wherein the multi-level inverter includes a first set of switching elements constituting a first series circuit connected between a first output point and a second output point of the multiple output points,
wherein in a first state, the control circuit is configured to turn on a first group of the first set of switching elements,
in a second state, the control circuit is configured to turn on a second group of the first set of switching elements, and
in a third state, the control circuit is configured to turn on a third group of the first set of switching elements.
15 . The refrigeration cycle device according to claim 14 , wherein the multi-level inverter further includes a second set of switching elements constituting a second series circuit connected between the first output point and the second output point of the multiple output points.
16 . The refrigeration cycle device according to claim 15 , wherein in the first state, the control circuit is configured to turn on a first group of the second set of switching elements,
in the second state, the control circuit is configured to turn on a second group of the second set of switching elements, and
in the third state, the control circuit is configured to turn on a third group of the second set of switching elements.