Variable speed drive
First Claim
1. A variable speed drive system configured to receive an input AC voltage at a fixed AC input voltage and provide an output AC power at a variable voltage and variable frequency, the variable speed drive comprising:
- a converter stage comprising at least two semiconductor switches for each power phase of the AC power source, the converter stage connected to an AC power source providing the input AC voltage, the converter stage being configured to convert the input AC voltage to a boosted DC voltage;
a DC link connected to the converter stage, the DC link being configured to filter and store the boosted DC voltage from the converter stage;
an inverter stage connected to the DC link, the inverter stage being configured to convert the boosted DC voltage from the DC link into the output AC power having the variable voltage and the variable frequency; and
a controller for interrupting fault current flowing to an input phase of the converter stage in response to at least one current sensor sensing a ground fault on an input of the converter stagewherein each of the at least two semiconductor switches comprising a pair of reverse blocking (RB) IGBTs inversely connected in parallel.
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Accused Products
Abstract
Systems and methods for improved Variable Speed Drives are provided. One embodiment relates to apparatus for common mode and differential mode filtering for motor or compressor bearing protection when operating with Variable Speed Drives, including conducted EMI/RFI input power mains mitigation. Another embodiment relates to a method to extend the synchronous operation of an active converter to the AC mains voltage during complete line dropout. Another embodiment relates to an active converter-based Variable Speed Drive system with Improved Full Speed Efficiency. Another embodiment relates to a liquid- or refrigerant-cooled inductor. The liquid- or refrigerant-cooled inductor may be used in any application where liquid or refrigerant cooling is available and a reduction in size and weight of a magnetic component is desired.
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Citations
16 Claims
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1. A variable speed drive system configured to receive an input AC voltage at a fixed AC input voltage and provide an output AC power at a variable voltage and variable frequency, the variable speed drive comprising:
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a converter stage comprising at least two semiconductor switches for each power phase of the AC power source, the converter stage connected to an AC power source providing the input AC voltage, the converter stage being configured to convert the input AC voltage to a boosted DC voltage; a DC link connected to the converter stage, the DC link being configured to filter and store the boosted DC voltage from the converter stage; an inverter stage connected to the DC link, the inverter stage being configured to convert the boosted DC voltage from the DC link into the output AC power having the variable voltage and the variable frequency; and a controller for interrupting fault current flowing to an input phase of the converter stage in response to at least one current sensor sensing a ground fault on an input of the converter stage wherein each of the at least two semiconductor switches comprising a pair of reverse blocking (RB) IGBTs inversely connected in parallel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A chiller system comprising:
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a refrigerant circuit comprising a compressor, a condenser arrangement and an evaporator arrangement connected in a closed loop; a drive arrangement connected to the compressor to power the compressor, the drive arrangement comprising a motor and a variable speed drive, the variable speed drive comprising; a converter stage comprising at least two semiconductor switches for each power phase of the AC power source, the converter stage connected to an AC power source providing the input AC voltage, the converter stage being configured to convert the input AC voltage to a boosted DC voltage;
a DC link connected to the converter stage, the DC link being configured to filter and store the boosted DC voltage from the converter stage; an inverter stage connected to the DC link, the inverter stage being configured to convert the boosted DC voltage from the DC link into the output AC power having the variable voltage and the variable frequency; a controller for interrupting fault current flowing to an input phase of the converter stage in response to at least one current sensor sensing a ground fault on an input of the converter stage wherein each of the at least two semiconductor switches comprising a pair of reverse blocking (RB) IGBTs inversely connected in parallel. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification