WO2008066000A1

WO2008066000A1 - Power supply charger and power supply charging method

Info

Publication number: WO2008066000A1
Application number: PCT/JP2007/072773
Authority: WO
Inventors: Takeshi Kokura
Original assignee: Daikin Industries, Ltd.
Priority date: 2006-11-29
Filing date: 2007-11-26
Publication date: 2008-06-05
Also published as: JP2008136316A

Abstract

A charger for charging a power converter with a reduced power consumption. A power supply (1) comprises a diode bridge (11) for rectifying an AC voltage from an AC power supply (E1) and a smoothing capacitor (13) for smoothing the DC voltage from the diode bridge (11). A charger (2) comprises a current-limiting capacitor (22) connected between the AC power supply (E1) and the power supply (1) and a switch section (21) for selecting either connection of the AC power supply (E1) to the diode bridge (11) through the current-limiting capacitor (22) or connection of the AC power supply (E1) to the diode bridge (11) by bypassing the current-limiting capacitor (22). A switch control section (3) controls the switch section (21) and charges the smoothing capacitor (13) through the current-limiting capacitor (22). Since the current-limiting capacitor (22) does not consume power except power consumption by the equivalent DC resistor, the power consumption is smaller than that of when the smoothing capacitor is charged through the current-limiting resistor.

Description

Specification

Charging device for power supply and charging method for power supply

Technical field

The present invention relates to a charging device for a power supply device and a charging method for the power supply device.

Background art

For example, a large-capacity smoothing capacitor is used for an inverter used in an air conditioner. Therefore, the smoothing capacitor is charged before the normal operation.

Such a smoothing capacitor charging operation is disclosed in Patent Document 1. In the initial charging device described in Patent Document 1, a power switch and a main power transformer are connected in series between an AC power source and a power converter (consisting of a rectifier circuit, a smoothing capacitor, and an inverter). A charging transformer, a charging switch, and a current limiting resistor are connected in series with a pair of the power switch and the main power transformer.

[0004] In the initial charging of the smoothing capacitor, the power switch is turned off and the charging switch is turned on to charge the smoothing capacitor via the charging transformer and the current limiting resistor.

[0005] Patent Document 1: Japanese Patent Laid-Open No. 2006-129571

Disclosure of the invention

Problems to be solved by the invention

[0006] However, the technique described in Patent Document 1 charges the smoothing capacitor via the current limiting resistor, so that there is a problem in that power consumption occurs at the current limiting resistor when the smoothing capacitor is charged.

Therefore, an object of the present invention is to provide a charging device for a power supply device that can reduce power consumption.

Means for solving the problem

[0008] A first aspect of the charging device of the power supply device according to the present invention includes a rectifying unit (11) that rectifies an AC voltage from the AC power source (E1) and converts the rectified voltage into a direct current, and a DC voltage from the rectifying unit. Is a charging device (2) of a power supply device (1) having a smoothing capacitor (13) that smoothes and supplies the load to a load (14, Ml), and is connected between the AC power supply and the rectifying unit Current-limiting capacitor (2 2), a switch that connects the AC power supply and the rectifier through the current-limiting capacitor, and a switch that connects the AC power supply and the rectifier bypassing the current-limiting capacitor. Part (21).

[0009] A second aspect of the power supply device charging device according to the present invention is the power supply device charging device according to the first aspect, wherein the load is a compressor driving motor (Ml) used in an air conditioner. ) Is an inverter (14) that supplies an alternating current.

[0010] A third aspect of the power supply apparatus charging device according to the present invention is the power supply apparatus charging apparatus according to the first or second aspect, wherein the switch unit includes the AC power supply and the rectifying unit. And a power switch (SW1) provided on one of the output lines (R, S, T) connecting between the two and a branch from one of the output lines, bypassing the power switch and again A line (23) provided with one of the output lines and provided with the current-limiting capacitor, and a current-limiting switch (SW2) connected in series with the current-limiting capacitor on the line.

[0011] A charging device for a power supply device according to a fourth aspect of the present invention is the charging device for a power supply device according to the first or second aspect, wherein the AC power supply has a neutral point (P1). The smoothing capacitor is composed of a first smoothing capacitor (13a) and a second smoothing capacitor (13b) connected in series on the output side of the rectifying unit, and the current limiting capacitor. Is connected between the neutral point and the connection point (P2) of the first smoothing capacitor and the second smoothing capacitor and on the side opposite to the rectifying unit, and the switch unit is A power switch (SW1) provided on one of the output lines connecting the AC power source and the input side of the rectifier without passing through a neutral point, and the neutral point and the connection point. And a current limiting switch connected in series with the current limiting capacitor.

[0012] A first aspect of the method for charging the power supply device according to the present invention includes a rectifying unit (11) that rectifies an AC voltage from an AC power source (E1) and converts the AC voltage into a DC voltage, and a DC voltage from the rectifying unit. And a smoothing capacitor (13) for smoothing and supplying the load (14, Ml) to the load (14, Ml), wherein the AC power is supplied to the load before the AC power is supplied to the load. The smoothing capacitor is charged through a current-limiting capacitor (22) connected to one of output lines (R, S, T) connecting the power source and the rectifier.

[0013] A second aspect of the method of charging the power supply device according to the present invention is the power supply device according to the first aspect. In the charging method, the load is an inverter (14) for supplying an alternating current to a compressor driving motor (Ml) used in an air conditioner.

The invention's effect

[0014] According to the first aspect of the charging device of the power supply device and the first aspect of the charging method of the power supply device according to the present invention, for example, a short circuit occurs between the rectifying unit and the load, and Even when a current continues to flow through the capacitor for a long time, the current-limiting capacitor has a small resistance, so unnecessary power consumption can be reduced.

[0015] Since an inverter used in an air conditioner has a large capacity, a large-capacity smoothing capacitor is used. Therefore, according to the second aspect of the charging device of the power supply device and the second aspect of the charging method of the power supply device according to the present invention, since the integrated current value flowing through the current limiting capacitor is increased, Compared with the case where the smoothing capacitor is charged, the power consumption is greatly reduced.

[0016] According to the third and fourth aspects of the charging device of the power supply device according to the present invention, it contributes to the realization of the charging device of the power supply device according to the first aspect.

[0017] The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

Brief Description of Drawings

FIG. 1 is a schematic configuration diagram of a charging device of a power conversion device according to an embodiment.

FIG. 2 is a diagram showing a charging voltage of a smoothing capacitor through a current limiting capacitor.

FIG. 3 is a diagram illustrating a charging voltage of a smoothing capacitor through a current limiting resistor.

FIG. 4 is a schematic configuration diagram of a charging device of the power conversion device according to the embodiment.

FIG. 5 is a schematic configuration diagram of a charging device of the power conversion device according to the embodiment.

FIG. 6 is a schematic configuration diagram of a charging device of the power conversion device according to the embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a schematic configuration diagram of a motor drive device using a power supply device charging device according to the present invention. The motor drive device includes a power supply device 1, a charging device 2, an inverter 14, an AC power supply E1, a motor Ml, and a switch control unit 3. As an example, the motor driving device drives a compressor in an air conditioner. [0020] The AC power supply El supplies an AC voltage between the output lines R, S, and T.

The charging device 2 includes a switch unit 21 and a current limiting capacitor 22. The switch unit 21 selects a state in which the AC power supply E1 and the power supply device 1 are connected via the current limiting capacitor 22, and a state in which the AC power supply E1 and the power supply device 1 are connected by bypassing the current limiting capacitor 22. Specifically, the switch unit 21 includes power switches SW1 and SW1, a line 23, and a current limiting switch SW2. The two power switches SW1 and SW1 are connected to the output lines R and T, respectively, and the connection / disconnection between the AC power supply E1 and the power supply 1 is selected. Note that the two power switches SW1 and SW1 are connected to any two output lines R, S, and T, respectively.

[0022] The line 23 branches from the output line R, bypasses the power switch SW1, and joins the output line R again. Note that the line 23 is not limited to the output line R, and may be branched or merged from any output spring provided with the power switch SW1.

The current limiting capacitor 22 is connected on the line 23. Current limiting switch SW2 is a line

23 is connected in series with the current limiting capacitor 22 and the connection / disconnection of the AC power supply E1 and the power supply 1 via the current limiting capacitor 22 is selected.

The power supply device 1 includes a diode bridge 11, a reactor 12, a smoothing capacitor 13, a high potential line 15a, and a low potential line 15b.

[0025] The diode bridge 11 includes diodes D1 to D6. Diode D1 and diode D2 force sword are connected, diode D3 anode and diode D4 force sword are connected, diode D5 anode and diode D6 force sword are connected, and AC is connected at each connection point. Connected to output lines R, S, T of power supply E1. The power swords of diodes Dl, D3, and D5 are connected to the high potential line 15a, and the anodes of the diodes D2, D4, and D6 are connected to the low potential line 15b.

[0026] Then, the diode bridge 11 performs full-wave rectification on the AC voltage from the AC power supply E1, converts it to a DC voltage, and outputs the DC voltage between the high potential line 15a and the low potential line 15b.

[0027] The rear tuttle 12 is connected to the high potential line 15a and reduces the ripple of the DC voltage from the diode bridge 11.

[0028] The smoothing capacitor 13 is in the rear stage of the rear tuttle 12, and one end is connected to the high potential line 15a. The other end is connected to the low potential line 15b to smooth the DC voltage from the diode bridge 11.

The inverter 14 receives the DC voltage from the smoothing capacitor 13 via the high potential line 15a and the low potential line 15b, converts it to an arbitrary AC voltage, and supplies it to the motor Ml.

[0030] The motor Ml is a compressor driving motor that drives a compressor used in the air conditioner according to the alternating current supplied from the inverter 14.

[0031] The switch controller 3 controls ON / OFF of the power switches SW1 and SW1 and the current limiting switch SW2.

Subsequently, the charging operation of the smoothing capacitor using the charging device according to the present invention will be described.

[0033] The switch control unit 3 turns on the current limiting switch SW2 before turning on the power by turning on the power switch SW1. Then, an alternating current flows between the output line R, the line 23, the current limiting switch SW2, and the current limiting capacitor 22 and the output line S, and the alternating current flows into the direct current via the diode bridge 11. Converted. Then, the direct current flows to the reactor 12 and the smoothing capacitor 13, and the smoothing capacitor 13 is charged.

FIG. 2 is a diagram illustrating an example of the charging voltage of the smoothing capacitor. Fig. 2 (a) is a diagram showing the charging voltage of the smoothing capacitor 13, Fig. 2 (b) is a diagram showing the current flowing through the current limiting capacitor 22, and Fig. 2 (c) is a diagram showing that the switch control unit 3 FIG. 6 is a diagram showing a switch signal output to a current limiting switch SW2. Note that FIG. 2 shows the values when the current-limiting capacitor 22 has a capacitance of 10 F, the rear tuttle 12 has an inductance of 1.7 mH, and the smoothing capacitor 13 has a capacitance of 1680〃F.

[0035] When the switch control unit 3 outputs a switch signal to the current limiting switch SW2 at time t = Is (see FIG. 2 (c)), the current limiting switch SW2 is turned ON, and current is supplied to the current limiting capacitor 22. The charge is accumulated in the smoothing capacitor 13 via the current limiting capacitor 22 (see FIG. 3 (a)). At this time, the voltage (charging voltage) across the smoothing capacitor 13 rises with a time constant based on the capacity of the current limiting capacitor 22, the inductance of the rear tuttle 12, and the capacity of the smoothing capacitor 13.

[0036] When a sufficient time (for example, 8 seconds in FIG. 2) elapses from the time when the current limiting switch SW2 is turned ON (time ijt = ls), the switch control is completed. Control unit 3 turns off current limiting switch SW2 and immediately turns on power switches SW1 and SW1 to supply power to inverter 14. Accordingly, after the smoothing capacitor 13 is sufficiently charged, normal operation is started. The switch control unit 3 detects the voltage across the smoothing capacitor 13, for example, and when the voltage exceeds a desired value, the switch control unit 3 OFFs the current limiting switch SW2 and promptly turns on the power switches SW1 and SW1. You may turn it on.

Here, for comparison, FIG. 3 shows a charging voltage of the smoothing capacitor 13 when a current limiting resistor is used instead of the current limiting capacitor 22. Fig. 3 (a) shows the voltage across the smoothing capacitor 13, Fig. 3 (b) shows the current flowing through the current limiting resistor, and Fig. 3 (c) shows the switch to the current limiting switch SW2. It is a figure which shows a signal. In addition, Fig. 3 shows the direct current when the current limiting resistance is 180 Ω, the inductance of the reactor 12 is 1.7 mH, and the capacitance of the smoothing capacitor 13 is 16 80 μF.

[0038] When the current limiting switch SW2 is turned on at time t = Is (see Fig. 3 (c)), a current flows through the current limiting resistor (see Fig. 3 (b)), and a smoothing capacitor is connected via the current limiting resistor. Charge is stored in 13 (see Fig. 3 (a)). As shown in FIG. 3 (b), while the smoothing capacitor 13 is charged, current continues to flow through the current limiting resistor. At this time, the current limiting resistor consumes power based on the current value and the resistance value of 180 Ω.

On the other hand, as shown in FIG. 2 (b), while the smoothing capacitor 13 is charged, the current S continues to flow through the current limiting capacitor 22, and the current limiting capacitor 22 has its equivalent DC resistance component. In principle, no power is consumed. Therefore, power consumption can be reduced compared to the case where the smoothing capacitor 13 is charged using the current limiting resistor.

[0040] In addition, as the capacity of the smoothing capacitor 13 increases, the time required for charging increases and the current flowing through the current limiting capacitor 22 (current limiting resistor) increases. Therefore, as the capacitance of the smoothing capacitor 13 increases, the effect of reducing power consumption when charging the smoothing capacitor 13 via the current limiting capacitor 22 increases.

Note that the charging device of the present invention is not limited to the force described as the charging device 2 of the power supply device 1 for the inverter 14 that supplies an alternating current to the compressor driving motor Ml used in the air conditioner. However, since the capacity of the inverter used in the air conditioner is generally large, the power supply device 1 is provided with a large-capacity smoothing capacitor 13. Therefore, this place In this case, the effect of reducing power consumption by the present invention is great.

[0042] Note that the AC power supply E1 may be a three-phase AC power supply having a neutral point P1. Figure 4 shows a motor drive device that uses a charging device for the power supply in this case. In addition, the same code | symbol shows the same or an equivalent part, and the overlapping description is abbreviate | omitted.

Compared with the motor drive device shown in FIG. 1, the smoothing capacitor 13 is composed of smoothing capacitors 13 a and 13 b connected in series on the output side of the diode bridge 11. The current limiting capacitor 22 is connected between the neutral point P1 and the connection point P2 of the smoothing capacitors 13a and 13b on the side opposite to the diode bridge 11! /. The current limiting switch SW2 is connected in series with the current limiting capacitor 22 between the neutral point P1 and the connection point P2.

[0044] Then, the switch control unit 3 turns on the current limiting switch SW2 prior to turning on the power by turning on the power switch SW1. Then, current flows through the closed circuit consisting of AC power supply El, output line S, diodes 3 and D4, smoothing capacitors 13a and 13b, current limiting capacitor 22 and current limiting switch SW2, and the smoothing capacitors 13a and 13b are charged with voltage. The Even in this case, since power is charged through the current limiting capacitor 22, power S can be reduced to reduce power consumption.

[0045] Further, the AC power supply E1 may be a single-phase AC power supply as shown in FIGS. In the motor drive device shown in FIG. 5, the diode bridge 11 is composed of four diodes D1 to D4. The power switch SW1 is connected to one of the output lines of the AC power supply E1. The other configuration is the same as that of the motor driving device shown in FIG.

[0046] In FIG. 6, compared to the motor drive device shown in FIG. 5, the smoothing capacitors 13a and 13b are on the output side of the diode bridge 11, and are connected in series between the high potential line 15a and the low potential line 15b. It has been. The smoothing capacitors 13a and 13b connected in series are connected in parallel with the smoothing capacitor 13.

[0047] In addition, the power factor improving switch SW3 is connected between the connection point P2 of the smoothing capacitors 13a and 13b and the single-phase AC power supply El! The power factor can be improved by controlling the power factor improving switch SW3 at a predetermined timing.

[0048] In any of the motor drive devices shown in Figs. 5 and 6, prior to turning on the power switch SW1 and turning on the power, the current limit switch SW2 is turned on and the current limiting capacitor is connected. By charging the smoothing capacitor 13 (or the smoothing capacitors 13, 13a, 13b), the power consumption can be reduced.

The present invention has been described in detail. The above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that the myriad variations S that are not illustrated can be assumed without departing from the scope of the present invention.

Claims

The scope of the claims

[1] A rectification unit (11) that rectifies an alternating voltage from an alternating current power supply (El) and converts it into direct current;

Smoothing capacitor that smoothes the DC voltage from the rectifier and supplies it to the load (14, Ml)

A charging device (2) of a power supply device (1) having (13),

A current limiting capacitor (22) connected between the AC power source and the rectifying unit; a state in which the AC power source and the rectifying unit are connected via the current limiting capacitor; and the AC power source and the rectifying unit; A switch portion (21) for selecting a state of bypassing the current limiting capacitor and connecting

A charging device for a power supply device.

2. The charging device for a power supply device according to claim 1, wherein the load is an inverter (14) that supplies an alternating current to a compressor driving motor (Ml) used in an air conditioner.

[3] The switch section is

A power switch (SW1) provided on one of output lines (R, S, T) connecting between the AC power source and the input side of the rectifying unit;

Branching from one of the output lines, bypassing the power switch and joining again with one of the output lines, the line (23) provided with the current limiting capacitor;

A current limiting switch (SW2) connected in series with the current limiting capacitor on the line;

The charging device for a power supply device according to claim 1, comprising:

[4] The AC power supply is a multiphase AC power supply having a neutral point (P1),

The smoothing capacitor includes a first smoothing capacitor (13a) and a second smoothing capacitor (13b) connected in series on the output side of the rectifying unit,

The current limiting capacitor is connected between the neutral point and a connection point (P2) of the first smoothing capacitor and the second smoothing capacitor and on the opposite side of the rectifying unit, Department

A power switch (SW1) provided on one of the output lines connecting the AC power supply and the input side of the rectifier without passing through the neutral point;

A current limiting device connected in series with the current limiting capacitor between the neutral point and the connection point For switch

The charging device for a power supply device according to claim 1, comprising:

[5] A rectifying unit (11) for rectifying an AC voltage from the AC power source (E1) and converting it to a DC, and a smoothing capacitor for smoothing the DC voltage from the rectifying unit and supplying it to a load (14, Ml) (13) A method of charging a power supply device (1) comprising:

Prior to supplying the AC power supply to the load, via a current limiting capacitor (22) connected to one of output lines (R, S, T) connecting the AC power supply and the rectifying unit. A method for charging a power supply apparatus, wherein the smoothing capacitor is charged.

6. The method for charging a power supply device according to claim 5, wherein the load is an inverter (14) that supplies an alternating current to a compressor driving motor (Ml) used in an air conditioner.