DC power-supply device and refrigeration-cycle application device including the same
First Claim
1. A DC power-supply device that converts an alternating current into a direct current and supplies the direct current to a load, comprising:
- a rectifier circuit to rectify the alternating current;
a reactor connected to an input side or an output side of the rectifier circuit;
a first capacitor and a second capacitor serially connected between output terminals to the load;
a charging unit to selectively charge one or both of the first capacitor and the second capacitor;
a first voltage detection unit to detect a voltage of the first capacitor;
a second voltage detection unit to detect a voltage of the second capacitor; and
a control unit to control the charging unit, wherein;
the control unit controls at least one of a charging period of the first capacitor and a charging period of the second capacitor,by changing at least of one of the charging period of the first capacitor and the charging period of the second capacitor with respect to a voltage difference between the first capacitor and the second capacitor at a first time, a voltage difference between the first capacitor and the second capacitor at a second time, which is after the first time, is made small,the alternating current is a three-phase alternating current,the control unit controls the charging unit in such a manner that, when a period obtained by combining a charging period and a non-charging period of a pair of the first capacitor and the second capacitor is designated as one cycle, a charging frequency becomes 3n times (n is a natural number) higher than a frequency of the three-phase alternating current, andthe charging frequency is an inverse number of the one cycle.
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Accused Products
Abstract
To provide a DC power-supply device that can suppress voltage unbalance of a plurality of capacitors serially connected between both terminals of a load, achieve stable drive of the load and long life of the capacitors, and contribute to high reliability, in a configuration in which an alternating current is converted into a direct current and is supplied to a load, and a refrigeration-cycle application device including the DC power-supply device. The DC power-supply device includes a rectifier circuit, a reactor connected to an input or an output side of the rectifier circuit, a first capacitor and a second capacitor serially connected between output terminals to a load, a charging unit that selectively charges one or both of the first capacitor and the second capacitor, and further includes a control unit that controls the charging unit so that voltage unbalance between the first capacitor and the second capacitor is suppressed.
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Citations
13 Claims
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1. A DC power-supply device that converts an alternating current into a direct current and supplies the direct current to a load, comprising:
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a rectifier circuit to rectify the alternating current; a reactor connected to an input side or an output side of the rectifier circuit; a first capacitor and a second capacitor serially connected between output terminals to the load; a charging unit to selectively charge one or both of the first capacitor and the second capacitor; a first voltage detection unit to detect a voltage of the first capacitor; a second voltage detection unit to detect a voltage of the second capacitor; and a control unit to control the charging unit, wherein; the control unit controls at least one of a charging period of the first capacitor and a charging period of the second capacitor, by changing at least of one of the charging period of the first capacitor and the charging period of the second capacitor with respect to a voltage difference between the first capacitor and the second capacitor at a first time, a voltage difference between the first capacitor and the second capacitor at a second time, which is after the first time, is made small, the alternating current is a three-phase alternating current, the control unit controls the charging unit in such a manner that, when a period obtained by combining a charging period and a non-charging period of a pair of the first capacitor and the second capacitor is designated as one cycle, a charging frequency becomes 3n times (n is a natural number) higher than a frequency of the three-phase alternating current, and the charging frequency is an inverse number of the one cycle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification