Frequency converter device which adaptively responds to a power failure
First Claim
1. A frequency converter device, comprising:
- a first converter in a pulse-width modulation system for converting an AC voltage into a DC voltage;
a second converter in a pulse-width modulation system for supplying an AC voltage with a variable voltage and a variable frequency to a motor;
a capacitor connected between an output side of said first converter and an input side of said second converter;
a current suppressing circuit connected to the input side of said first converter and consisting of a resistor and a short-circuiting means;
a detection circuit for detecting the presence or absence of a power supply inputted to said first converter;
a circuit for measuring the voltage across said capacitor;
a drive control circuit for stopping the conversion of said first converter when power failure of the input power supply occurs and when the voltage across the capacitor is not smaller than a prescribed value, continuing the drive state of the short-circuiting means in said current suppressing circuit and said second converter, thereby continuing an output.
1 Assignment
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Accused Products
Abstract
A frequency converter device comprises a first converter 5 in a pulse-width modulation system for converting an AC voltage into a DC voltage; a second converter 2 in a pulse-width modulation system for supplying an AC voltage with a variable voltage and a variable frequency to a motor; a capacitor 15 connected between an output side of said first converter 5 and an input side of said second converter 15; a current suppressing circuit connected to the input side of said first converter 5 and consisting of a resistor 31 and a relay 32; a detection circuit 19 for detecting the presence or absence of the power supply inputted to said first converter 5; a circuit 16 for measuring the voltage across said capacitor 15; a drive control circuit 30a for stopping the conversion of said first converter 5 when power failure of an input power supply occurs and when the voltage across the capacitor is not smaller than a prescribed value, continuing the drive state of the relay 32 and said second converter 2, thereby continuing an output.
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Citations
7 Claims
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1. A frequency converter device, comprising:
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a first converter in a pulse-width modulation system for converting an AC voltage into a DC voltage; a second converter in a pulse-width modulation system for supplying an AC voltage with a variable voltage and a variable frequency to a motor; a capacitor connected between an output side of said first converter and an input side of said second converter; a current suppressing circuit connected to the input side of said first converter and consisting of a resistor and a short-circuiting means; a detection circuit for detecting the presence or absence of a power supply inputted to said first converter; a circuit for measuring the voltage across said capacitor; a drive control circuit for stopping the conversion of said first converter when power failure of the input power supply occurs and when the voltage across the capacitor is not smaller than a prescribed value, continuing the drive state of the short-circuiting means in said current suppressing circuit and said second converter, thereby continuing an output. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification