Power transducer
First Claim
1. A power transducer which outputs alternating current (AC) power having a variable voltage and a variable frequency, the power transducer comprising:
- a converter for rectifying the AC voltage of an AC power supply to convert it to a direct current (DC) voltage;
a DC intermediate circuit having a smoothing capacitor for smoothing the DC voltage of the converter;
a detecting circuit for detecting the voltage of the DC intermediate circuit;
a regenerative braking circuit disposed in the DC intermediate circuit;
a drive circuit for driving the regenerative braking circuit when the detecting circuit detects a specified voltage;
a timer for accumulating the operating time of the regenerative braking circuit to obtain the cumulative operating time; and
an inverter for converting the DC voltage of the converter to an AC voltage,wherein a permissible duty factor and a resistance value of a regenerative braking resistor connected to the regenerative braking circuit of the DC intermediate circuit are individually set.
1 Assignment
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Accused Products
Abstract
The performance of a power transducer is improved while efficiently using a power semiconductor also by managing the permissible duty factor of the power semiconductor in the regenerative braking circuit provided in the power transducer. The user is allowed to set, through an operation panel provided on the power transducer, the resistance value of the regenerative braking resistor for thermally consuming the rotational energy generated during motor deceleration. The power transducer performs the steps of: calculating the current which flows in the regenerative braking circuit from the resistance value setting; obtaining the generation loss of the power semiconductor in the regenerative braking circuit with the calculated current value; and determining the permissible duty factor of the power semiconductor from the obtained generation loss.
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Citations
8 Claims
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1. A power transducer which outputs alternating current (AC) power having a variable voltage and a variable frequency, the power transducer comprising:
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a converter for rectifying the AC voltage of an AC power supply to convert it to a direct current (DC) voltage; a DC intermediate circuit having a smoothing capacitor for smoothing the DC voltage of the converter; a detecting circuit for detecting the voltage of the DC intermediate circuit; a regenerative braking circuit disposed in the DC intermediate circuit; a drive circuit for driving the regenerative braking circuit when the detecting circuit detects a specified voltage; a timer for accumulating the operating time of the regenerative braking circuit to obtain the cumulative operating time; and an inverter for converting the DC voltage of the converter to an AC voltage, wherein a permissible duty factor and a resistance value of a regenerative braking resistor connected to the regenerative braking circuit of the DC intermediate circuit are individually set. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification