JP2010178408A - Dc power supply apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress reactor noise, generated in synchronism with a reactor short-circuit operation, in a load around a boundary where the occurrence of the reactor short-circuit operation for adjusting a DC power supply voltage starts. <P>SOLUTION: By a control part 9, an on-period Δt (0≤t) is varied, with reference to a difference between a target DC voltage and an output of a DC voltage detection means, in order to control a DC voltage to a desired value, but the on-period Δt is shifted from 0 to a value exceeding 0, when the load quantity detected by a load quantity detecting means 10 is over a preset value, avoiding the alternate occurrence of a power supply cycle, where the current short-circuiting the switching portion flows in a reactor 5 and the power supply cycle where the short-circuiting current does not flow, even in an input current around the boundary where the on-period Δt is 0 or exceeds 0 so that noises are not generated from the reactor and sound reduction is attained in the DC power supply apparatus. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a DC power supply device that controls a power supply circuit, and more particularly to a DC power supply device that uses a DC voltage variable function of a power factor correction circuit, and an air conditioner that uses the DC power supply device.

  The DC power supply device includes a rectifying / smoothing unit that rectifies and smoothes an AC voltage from an AC power source into a DC voltage, a reactor connected between the AC power source and one AC input terminal of the rectifying / smoothing unit, and the AC Switching means for short-circuiting a power supply via the reactor, zero-cross detection means for detecting a zero-cross point of the AC power supply, DC voltage detection means for detecting and outputting an output DC voltage value of the rectifying and smoothing means, and the DC voltage Referring to the output of the detection means, the control means is configured to short-circuit the switching means continuously only during the ON period Δt (0 ≦ t) after the delay period Δd (0 ≦ d) of the zero cross point. The control means changes the delay period Δd (0 ≦ d) and the on period Δt (0 ≦ t), thereby controlling the output DC voltage value.

  Conventionally, in order to control the DC voltage to a desired value, the control means refers to the difference between the target DC voltage and the output of the DC voltage detecting means and varies the ON period Δt (0 ≦ t). Is done. (For example, refer to Patent Document 1).

FIG. 4 shows a conventional DC power supply device described in Patent Document 1. In FIG. As shown in FIG. 4, the DC power supply device converts an AC voltage from the AC power supply 1 into a DC voltage by the rectifying and smoothing unit 2, and the ripple component of the DC voltage is deleted by the smoothing capacitor. The smoothed DC voltage is input to the inverter unit 3, and the electric motor 4 is driven. Further, a reactor 5 is connected between the AC power source 1 and one AC input terminal, and a short-circuit portion 6 that short-circuits the AC power source 1 through the reactor 5 and a zero cross point of the AC power source 1 are detected. A zero-cross detecting unit 7 for detecting, a DC voltage detecting unit 8 for detecting and outputting an output DC voltage value of the rectifying and smoothing unit, and a delay period Δd (0 ≦ d) of the zero-crossing point with reference to the output of the DC voltage detecting unit ) A control unit 9 for continuously short-circuiting the switching unit only during the ON period Δt (0 ≦ t) is connected. The controller 9 refers to the difference between the target DC voltage and the output of the DC voltage detecting means to vary the ON period Δt (0 ≦ t) in order to control the DC voltage to a desired value. FIG. 5 shows the relationship between the current input from the AC power supply to the DC power supply and the ON period Δt. When the target DC voltage is 255 V at AC 200 V, the ON period Δt becomes greater than 0 at 3.0 A or more. As the input current increases, the ON period Δt increases and the DC power supply voltage is maintained at a constant value.
JP 2004-72806 A

  However, in the conventional configuration, in the input current near the boundary where the ON period Δt is greater than 0 and 0, depending on the load of the DC power supply, the current that short-circuits the switching unit does not flow with the power supply cycle in which the reactor flows. Power supply cycles may occur alternately. Since the noise level generated from the reactor is different between the power cycle in which the short-circuit current flows in the reactor and the power cycle in which the short-circuit current does not flow, there is a problem that abnormal noise is generated from the reactor due to the difference in the noise level in each power cycle.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a DC power supply device that controls a DC voltage to a predetermined value without generating abnormal noise from a reactor.

  In order to solve the conventional problems, a DC power supply apparatus according to the present invention includes a rectifying / smoothing means for rectifying and smoothing an AC voltage from an AC power supply into a DC voltage, and an AC input of one of the AC power supply and the rectifying / smoothing means. A reactor connected between the terminals, a switching means for short-circuiting the AC power supply via the reactor, a zero-cross detection means for detecting a zero-cross point of the AC power supply, and an output DC voltage value of the rectifying and smoothing means DC voltage detecting means for detecting and outputting, and referring to the output of the DC voltage detecting means, continuously during the ON period Δt (0 ≦ t) after the delay time Δd (0 ≦ d) of the zero cross point. A DC power supply device including a control unit that short-circuits the switching unit is provided with a load amount detection unit that detects a load amount.

  The control means controls the ON period Δt so that the output of the DC voltage detection means becomes a target DC voltage, and the load amount detection means shifts the ON period Δt from 0 to a value exceeding 0. The detected load amount is equal to or greater than a preset value.

  As a result, even in the case of the input current near the boundary where the ON period Δt is greater than 0, it is avoided that the power cycle in which the current short-circuited the switching unit flows and the power cycle in which the current does not flow alternately occur. It becomes possible.

  In the DC power supply device of the present invention, since the power supply cycle in which the current short-circuited the switching unit does not flow and the power supply cycle in which the current does not flow do not occur alternately, abnormal noise is not generated from the reactor, and noise of the DC power supply device can be reduced. It becomes.

  The first invention comprises a rectifying / smoothing means for rectifying and smoothing an AC voltage from an AC power supply into a DC voltage, a reactor connected between the AC power supply and one AC input terminal of the rectifying / smoothing means, Switching means for short-circuiting an AC power supply via the reactor, zero-cross detection means for detecting a zero-cross point of the AC power supply, DC voltage detection means for detecting and outputting an output DC voltage value of the rectifying and smoothing means, and the DC DC having a control means for continuously short-circuiting the switching means only during the ON period Δt (0 ≦ t) after the delay period Δd (0 ≦ d) of the zero crossing point with reference to the output of the voltage detection means In the power supply device, load amount detection means for detecting a load amount of the DC power supply device is provided, and the control means is configured to turn on period Δ so that the output of the DC voltage detection means becomes a target DC voltage. Controls, the the on-period △ t is shifted to a value greater than 0 from 0 to when the amount detected load is equal to or greater than a preset value, which in the load detecting means.

  As a result, even in the case of the input current near the boundary where the on period Δt is greater than 0, it is possible to avoid alternately generating a power cycle in which the current short-circuiting the switching unit flows and a power cycle in which the current does not flow. Since the power cycle in which the current when the switching unit is short-circuited does not occur alternately and the power cycle in which the current does not flow in the reactor does not occur, no abnormal noise is generated from the reactor, and the noise of the DC power supply device can be reduced.

The second invention includes a rectifying / smoothing means for rectifying and smoothing an AC voltage from an AC power source into a DC voltage, a reactor connected between the AC power source and one AC input terminal of the rectifying / smoothing means, Switching means for short-circuiting an AC power supply via the reactor, zero-cross detection means for detecting a zero-cross point of the AC power supply, DC voltage detection means for detecting and outputting an output DC voltage value of the rectifying and smoothing means, and the DC With reference to the output of the voltage detection means, the switching is performed continuously only during the ON period Δt (0 ≦ t) after the delay period Δd (0 ≦ d) of the zero crossing point once or a plurality of times during a half cycle of the power supply. A DC power supply device having a control means for short-circuiting means, provided with a load amount detection means for detecting a load amount of the DC power supply device, wherein the control means has an output of the DC voltage detection means. The ON period Δt is controlled so as to become a DC voltage, and the number of times of switching during one half cycle of the power supply shifts from one time to a plurality of times when the load amount detected by the load amount detecting means exceeds a preset value. To do.

  As a result, even in the case of the input current near the boundary where the plurality of ON periods Δt are greater than 0 and 0, the power cycle in which the current short-circuiting the switching unit flows to the reactor and the power cycle in which the current does not flow alternately occur. Therefore, the power cycle in which the current short-circuited in the switching unit does not flow alternately and the power cycle in which the current does not flow are not alternately generated, so that no abnormal noise is generated from the reactor and the noise of the DC power supply device can be reduced.

  In particular, the third invention uses the direct-current power supply device of the first to second inventions in an air conditioner having a heat exchanger temperature detecting means in each of the indoor unit and the outdoor unit, and during heating operation, Using the indoor heat exchanger temperature detection means arranged in the heat exchanger of the machine, and during the cooling operation, using the outdoor heat exchanger temperature detection means arranged in the heat exchanger of the outdoor unit, the heat exchange detected in each operation state By using the temperature as a load amount in the three-phase motor, an inexpensive and low-noise air conditioner is realized without newly providing load amount detection means.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a block diagram according to the first embodiment of the present invention. The DC power supply device converts an AC voltage from the AC power supply 1 into a DC voltage by the rectifying and smoothing unit 2, and a ripple component of the DC voltage is deleted by the smoothing capacitor. The smoothed DC voltage is input to the inverter unit 3, and the electric motor 4 is driven. A reactor 5 is connected between the AC power source 1 and one AC input terminal, and a short-circuit unit (switching unit) 6 that short-circuits the AC power source 1 via the reactor 5, and the AC power source 1. A zero-cross point detecting unit 7 for detecting a zero-cross point, a DC voltage detecting unit 8 for detecting and outputting an output DC voltage value of the rectifying and smoothing unit, and a delay period Δd of the zero-cross point with reference to the output of the DC voltage detecting unit A controller 9 is connected that continuously short-circuits the switching unit only during the ON period Δt (0 ≦ t) after (0 ≦ d). The motor 4 is provided with load amount detection means 10 for detecting the load amount, and the load amount detected by the load amount detection means is input to the control unit 9. The control unit 9 refers to the difference between the target DC voltage and the output of the DC voltage detecting means to control the DC voltage to a desired value and varies the ON period Δt (0 ≦ t). Δt shifts from 0 to a value greater than 0 when the load amount detected by the load amount detection means becomes equal to or greater than a preset value.

  The operation and action of the DC power supply device configured as described above will be described below.

FIG. 2 shows the relationship between the current input from the AC power source to the DC power supply device and the ON period Δt. When the target DC voltage is 255 V at AC 200 V, the DC is AC 3.0 A with the ON period Δt being zero. The voltage matches the target DC voltage. When the current input to the DC power supply device becomes larger than AC 3.0A, the DC voltage is lower than the target DC voltage, but the load amount detected by the load amount detecting means is equal to or greater than a preset load amount. Up to 8A, the on period Δt continues to be zero.
When AC is over 3.8 A, the ON period Δt becomes larger than 0. Note that when the input current decreases from AC 3.8 A or more, the ON period Δt becomes 0 at AC 3.0 A.
When the input current is stable in the vicinity of AC 3.0 A, it is possible to avoid alternately generating a power cycle in which the current short-circuiting the switching unit flows through the reactor and a power cycle in which the current does not flow. Since the power supply cycle in which the current that short-circuits the switching unit does not flow in the reactor and the power cycle in which the current does not flow are not alternately generated, no abnormal noise is generated from the reactor, and noise in the DC power supply device can be reduced.

(Embodiment 2)
FIG. 3 is a block diagram according to the second embodiment of the present invention. 11 is an indoor unit of an air conditioner, 12 is an outdoor unit, and 13 is a compressor.

  By using the outdoor heat exchange temperature detected by the outdoor heat exchanger temperature detection means 15 during the cooling operation as the load amount and the indoor heat exchanger temperature detected by the indoor heat exchanger temperature detection means 14 during the heating operation, the load amount detection means Thus, an inexpensive and low-noise air conditioner is realized without newly providing 10.

  As described above, the direct-current power supply device according to the present invention can supply direct-current voltage while suppressing reactor noise, so that it operates at night such as an air conditioner or a heat pump hot water heater and requires quietness. Applicable to household electrical appliances.

Block diagram of DC power supply apparatus according to Embodiment 1 of the present invention Relationship diagram between current input to DC power supply device and on-period Δt in Embodiment 1 of the present invention The block diagram of the air conditioner in Embodiment 2 of this invention Block diagram of a conventional DC power supply device described in Patent Document 1 Relationship diagram between current input to conventional DC power supply device and on-period Δt in Patent Document 1

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Rectification smoothing part 3 Inverter part 4 Electric motor 5 Reactor 6 Short circuit part 7 Zero cross detection part 8 DC voltage detection part 9 Control part 10 Load amount detection means 11 Air conditioner indoor unit 12 Air conditioner outdoor unit 13 Compression Machine 14 Indoor heat exchanger temperature detection means 15 Outdoor heat exchanger temperature detection means

Claims (3)

Rectifying and smoothing means for rectifying and smoothing an AC voltage from an AC power supply into a DC voltage, a reactor connected between the AC power supply and one AC input terminal of the rectifying and smoothing means, and the AC power supply for the reactor Switching means that is short-circuited through, a zero-cross detection means that detects a zero-cross point of the AC power supply, a DC voltage detection means that detects and outputs an output DC voltage value of the rectifying and smoothing means, and an output of the DC voltage detection means A direct current power supply apparatus comprising: a control means for continuously short-circuiting the switching means only during an on period Δt (0 ≦ t) after a delay period Δd (0 ≦ d) of the zero cross point; Load amount detection means for detecting the load amount of the power supply device is provided, and the control means controls the ON period Δt so that the output of the DC voltage detection means becomes a target DC voltage, DC power supply device, characterized in that the on-period △ t is shifted to a value greater than 0 from 0 is when the load amount detected by the load detecting means is equal to or higher than a preset value. Rectifying and smoothing means for rectifying and smoothing an AC voltage from an AC power supply into a DC voltage, a reactor connected between the AC power supply and one AC input terminal of the rectifying and smoothing means, and the AC power supply for the reactor Switching means that is short-circuited through, a zero-cross detection means that detects a zero-cross point of the AC power supply, a DC voltage detection means that detects and outputs an output DC voltage value of the rectifying and smoothing means, and an output of the DC voltage detection means Control means for continuously short-circuiting the switching means only during the ON period Δt (0 ≦ t) after the delay period Δd (0 ≦ d) of the zero crossing point once or a plurality of times during a half cycle of the power source A load amount detecting means for detecting a load amount of the DC power supply apparatus, and the control means is configured such that the output of the DC voltage detecting means becomes a target DC voltage. The ON period Δt is controlled so that the number of times of switching during one half cycle of the power supply shifts from one time to a plurality of times when the load amount detected by the load amount detection means becomes equal to or greater than a preset value. A direct current power supply device. The air conditioner indoor unit heat exchanger has an indoor heat exchanger temperature detecting means for detecting the heat exchanger temperature, and the outdoor unit heat exchanger has an outdoor heat exchanger temperature detecting means for detecting the heat exchanger temperature. The heat exchanger temperature is detected by using the indoor heat exchanger temperature detecting means arranged in the indoor unit during the heating operation, and the outdoor heat exchanger temperature detecting means arranged in the outdoor unit during the cooling operation, and the detected heat exchange is detected. An air conditioner using the DC power supply device according to claim 1, wherein the temperature of the unit is a load amount of the DC power supply device.

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