Heat source unit

Abstract

This reduces the installation costs of an active filter device for reducing harmonic currents generated by an inverter device. [Solution] The inverter device (20) has a converter circuit (21) and an inverter circuit (24). The AC power supply (11) and the converter circuit (21) are connected via a power supply line (12). A noise filter circuit (30) is connected to the power supply line (12). An active filter device (40) is connected in parallel to the power supply line (12) between the noise filter circuit (30) and the converter circuit (21). The inverter device (20) and the active filter device (40) are housed in a single housing (15).

Description

Technical Field

[0001] The present invention relates to a heat source unit.

Background Art

[0002] Conventionally, in an air conditioner, an inverter device has been used to supply AC power to the motor of a compressor. The inverter device has a converter circuit that rectifies AC power from an AC power source into DC power, and an inverter circuit that converts the output power of the converter circuit into AC power of a predetermined frequency. When rectifying AC power into DC power, harmonic currents flow in the power supply system.

[0003] Therefore, in Patent Document 1, an active filter generates a compensation current with the same amplitude as the harmonic current generated by the inverter device and a phase shifted by 180°, and uses this compensation current to cancel out the harmonic current.

[0004] Also, as the installation location of the active filter, Patent Document 2 discloses a configuration in which the inverter main circuit constituting the controller is installed in the middle and on the front side inside the housing of the outdoor unit, while the AF housing accommodating the harmonic suppression device is installed at a substantially intermediate position of the housing of the outdoor unit.

[0005] Further, Patent Document 3 discloses a configuration in which a control device equipped with an inverter device and a housing of a harmonic suppression device are arranged inside the housing of an outdoor unit.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] By the way, in the conventional invention, after the active filter device is housed in a housing separate from the housing in which the inverter device is housed, the inverter device and the active filter device are arranged in the outdoor unit.

[0008] Therefore, an active filter device In addition to the member cost of the housing for housing, terminal blocks, wiring, etc. for the active filter device is separately required, and there is a problem that the installation cost of the active filter device increases.

[0009] The present invention has been made in view of such points, and its object is Installation of an active filter device for reducing harmonic currents generated in the inverter device to reduce costs.

Means for Solving the Problems

[0010] The present invention is directed to a heat source unit including a power conversion device (10) having a housing (15) and an inverter device (20) housed in the housing (15), and a compressor (52) connected to the inverter device (20) via an electrical wiring (13), and the following solution means are taken.

[0011] That is, in the first invention, the compressor (52) is disposed in the main body portion (51) of the heat source unit, the housing (15) is disposed in the main body portion (51), the inverter device (20) has a converter circuit (21) that rectifies AC power from an AC power source (11) into DC power, and an inverter circuit (24) that converts the output power of the converter circuit (21) into AC power of a predetermined frequency, and a noise filter circuit (30) connected to a power line (12) connecting the AC power source (11) and the converter circuit (21), inside the housing (15) is, an active filter device (40) that is connected in parallel between the noise filter circuit (30) and the converter circuit (21) in the power supply line (12) to reduce the harmonic current flowing out from the inverter device (20) and Other optional devices and are Contain performed It is characterized by this.

[0012] In the first invention, an active filter device (40) and Other optional devices together with is housed in the housing (15) in which the inverter device (20) is housed, so that the active filter device (40) and Other optional devices and There is no need to separately provide a dedicated housing (15) for housing it. As a result, the member cost of the housing (15) can be suppressed, and the design cost, processing cost, management cost, etc. of the housing (15) can also be reduced.

[0013] Also, by connecting the active filter device (40) in parallel between the noise filter circuit (30) and the converter circuit (21) in the power line (12), the noise filter circuit (30) of the inverter device (20) is made to be commonly used also for the active filter device (40). As a result, there is no need to separately provide a noise filter circuit (30) dedicated to the active filter device (40), terminal blocks, etc., and the size of the entire device can be reduced and a significant cost reduction can be achieved.

[0014] The second invention is, in the first invention, The optional device is characterized in that it is a transformer.

[0015] The third invention is, in the first invention, The optional device is characterized in that it is an overvoltage suppression device.

[0016] The fourth invention is, in any one of the first to third inventions, It includes a current transformer (35) for detecting the current flowing through the power supply line (12), The current transformer (35) has a split core that enables the operation of inserting the power supply line (12) through the current transformer (35) in a state where the power supply line (12) is connected to the noise filter circuit (30) and the inverter device (20). It is characterized by this.

[0017] In the fourth invention, by using a current transformer (35) having a split core, the operation of inserting the power line (12) through the current transformer (35) can be performed without removing the power line (12) from the terminal block.

[0018] This reduces the man-hours for assembling the current transformer (35), suppresses problems such as incorrect wiring and insufficient terminal tightening that may occur when the power line (12) is removed from the terminal block, and ensures the reliability of the power conversion device.

[0019] The fifth invention is based on the first invention, An air-cooling fan (55) is disposed outside the housing (15), The inverter device (20) is disposed below the air-cooling fan (55) inside the housing (15) 、 Before The noise filter circuit (30) and the active filter device (40) are disposed in parallel below the inverter device (20) inside the housing (15).

[0020] In the fifth invention, by disposing the inverter device (20) near the air-cooling fan (55) inside the housing (15), the inverter device (20) as a heat source can be cooled by utilizing the air flow by the air-cooling fan (55).

[0021] Also, by disposing the noise filter circuit (30) and the active filter device (40) in parallel, the electrical wiring between the circuits can be connected at the shortest distance, and miniaturization and cost reduction of the entire device can be achieved.

[0022] The sixth invention is based on any one of the first to fifth inventions, A connection port for the electrical wiring (13) is provided above the compressor (52), The inverter device (20) is disposed above the compressor (52) within the housing (15), The electrical wiring (13) is routed upward from the lower side of the inverter device (20) above the compressor (52) and connected to the connection port of the compressor (52).

[0023] In the sixth invention, the inverter device (20) is disposed above the compressor (52) within the housing (15). Then, the electrical wiring (13) connecting the inverter device (20) and the compressor (52) is routed from the lower side of the inverter device (20) and connected to the connection port above the compressor (52).

[0024] Thereby, the electrical wiring (13) connecting the inverter device (20) and the compressor (52) can be routed over the shortest distance, and the influence of noise generated by the inverter device (20) can be minimized.

Effect of the Invention

[0025] According to the present invention, The inverter device (20) and the active filter device (40) are housed in the same housing (15), and by sharing the noise filter circuit (30), the size of the entire device is reduced and the cost is reduced it can be achieved.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present invention, its applications, or its uses.

[0028] 《Embodiment 1》 Figure 1 is a circuit diagram showing the configuration of the power conversion device according to Embodiment 1. As shown in Figure 1, the power conversion device (10) includes an inverter device (20), a noise filter circuit (30), and an active filter device (40). The inverter device (20), the noise filter circuit (30), and the active filter device (40) are housed in a single housing (15).

[0029] The inverter device (20) converts the load current from an AC power supply (11) that outputs three-phase alternating current into a current of a desired frequency and supplies it to a motor (53). The motor (53) is a three-phase AC motor and drives, for example, a compressor (52) provided in the refrigerant circuit of an air conditioner (see Figure 2).

[0030] The housing (15) is provided with a power supply side terminal block (16) for a power line (12) connecting the AC power supply (11) and the inverter device (20), and a motor side terminal block (17) for an electrical wiring (13) connecting the inverter device (20) and the motor (53).

[0031] In this embodiment, the AC power supply (11) will be described as a power supply that outputs three-phase alternating current. However, the AC power supply (11) may be a power supply that outputs single-phase alternating current or alternating current of other numbers of phases.

[0032] The inverter device (20) includes a converter circuit (21), a reactor (22), a smoothing capacitor (23), an inverter circuit (24), and a control circuit (25).

[0033] The converter circuit (21) is connected to the AC power supply (11) via the power line (12), full-wave rectifies the alternating current output from the AC power supply (11), and outputs a pulsating direct current, that is, a pulsating current. The converter circuit (21) is composed of a plurality of diodes.

[0034] A noise filter circuit (30) is connected to a power line (12) that connects an AC power supply (11) and a converter circuit (21). The noise filter circuit (30) removes noise associated with the switching operation of the inverter circuit (24).

[0035] One end of the reactor (22) is connected to one output node of the converter circuit (21), and the other end of the reactor (22) is connected between one of the input nodes of the inverter circuit (24).

[0036] The smoothing capacitor (23) is connected to the other end of the reactor (22) and the other output node of the converter circuit (21). The smoothing capacitor (23) is connected between the output nodes of the converter circuit (21) via the reactor (22), and a pulsating DC voltage output from the converter circuit (21) is applied to the smoothing capacitor (23). Also, the smoothing capacitor (23) is connected between two input nodes of the inverter circuit (24).

[0037] The reactor (22) and the smoothing capacitor (23) constitute an LC filter. The inductance of the reactor (22) and the capacitance of the smoothing capacitor (23) are set such that this LC filter attenuates a current component having the same frequency as the frequency of the carrier used for generating the control signal of the inverter circuit (24). Therefore, it is possible to suppress the outflow of the current component having the same frequency as the frequency of the carrier to the AC power supply (11).

[0038] The inverter circuit (24) has a plurality of switching elements. Also, a freewheeling diode is connected in anti-parallel to the switching element. The inverter circuit (24) converts its input voltage into a three-phase AC voltage by the on-off operation of these switching elements and supplies it to the motor (53).

[0039] The control circuit (25) generates a control signal for operating the switching element so that the motor (53) rotates at a desired speed, using a carrier at a predetermined frequency (for example, about 5 kHz), and outputs it to the switching element.

[0040] A current transformer (35) is provided in the power supply line (12). The current transformer (35) detects the current flowing through the power supply line (12) and has a split core. The current value detected by the current transformer (35) is input to the active filter device (40).

[0041] The active filter device (40) is connected in parallel between the noise filter circuit (30) and the converter circuit (21) in the power supply line (12). The active filter device (40) reduces the harmonic current flowing out from the inverter device (20) to the power supply line (12) by compensating for the harmonic current having a reverse phase to the harmonic current generated in the inverter device (20) based on the current value flowing through the inverter device (20) detected by the current transformer (35).

[0042] Specifically, the active filter device (40) includes a switching circuit (41) having a plurality of switching elements, a capacitor (42) for smoothing the output power of the switching circuit (41), a carrier filter (43) for removing the noise associated with the switching of the switching circuit (41), a coupling reactor (44) for coupling the switching circuit (41) and the power supply line (12), and a control circuit (45) for controlling the switching of the switching circuit (41).

[0043] The switching circuit (41), the capacitor (42), the carrier filter (43), the coupling reactor (44), and the control circuit (45) are mounted on the same substrate. This eliminates the need for a harness for connecting between the circuits, aiming to reduce the size and cost of the entire device.

[0044] The carrier filter (43) removes the high-frequency component of the compensation current (the component of the current generated by the switching of the switching circuit (41)). The switching circuit (41) is controlled in its switching operation by the control circuit (45), and by controlling the current flowing between the AC power supply (11) and the switching circuit (41), it cancels out the harmonic current flowing out from the inverter device (20) to the power line (12).

[0045] As also shown in FIG. 2, the inverter device (20), the noise filter circuit (30), and the active filter device (40) are disposed inside the heat source unit (50) while being housed in one housing (15).

[0046] The heat source unit (50) is an outdoor unit provided in the refrigerant circuit of the air conditioner. Inside the main body (51) of the heat source unit (50), a compressor (52), an air-cooling fan (55), a heat exchanger (not shown), and the like are disposed.

[0047] The air-cooling fan (55) is disposed at a position near the top inside the main body (51) of the heat source unit (50) and is configured to blow air upward. The compressor (52) is placed on the bottom surface inside the main body (51) of the heat source unit (50).

[0048] The housing (15) in which the inverter device (20), the noise filter circuit (30), and the active filter device (40) are housed is disposed inside the main body (51) of the heat source unit (50).

[0049] The inverter device (20) is disposed at a position near the air-cooling fan (55) inside the housing (15), that is, at a position near the top. Thereby, by utilizing the air flow by the air-cooling fan (55), the inverter device (20) serving as a heat generation source can be cooled.

[0050] The noise filter circuit (30) and the active filter device (40) are arranged in parallel below the inverter device (20) in the housing (15). Thereby, the electrical wiring between each circuit can be connected at the shortest distance.

[0051] Also, in the main body (51) of the heat source unit (50), the housing (15) and the compressor (52) are arranged side by side. And the inverter device (20) in the housing (15) and the compressor (52) are connected via the electrical wiring (13).

[0052] Specifically, a connection port for the electrical wiring (13) is provided above the compressor (52). And the inverter device (20) is arranged above the compressor (52) in the housing (15). The electrical wiring (13) is routed from the lower side of the inverter device (20) and connected to the connection port of the compressor (52).

[0053] Thereby, the electrical wiring (13) connecting the inverter device (20) and the compressor (52) can be wired at the shortest distance, and the influence of the noise generated by the inverter device (20) can be minimized.

[0054] As described above, according to the power conversion device (10) according to the first embodiment, since the active filter device (40) is housed together in the housing (15) in which the inverter device (20) is housed, there is no need to separately provide a dedicated housing (15) for housing the active filter device (40).

[0055] Also, by connecting the active filter device (40) in parallel between the noise filter circuit (30) and the converter circuit (21) in the power line (12), the noise filter circuit (30) of the inverter device (20) is also commonly used for the active filter device (40).

[0056] As a result, there is no need to separately provide a noise filter circuit (30) dedicated to the active filter device (40), a terminal block, etc., and the size of the entire device can be reduced and the cost can be significantly reduced.

[0057] Also, in order to detect the current flowing through the power line (12), a current transformer (35) having a split core is used, so that the power line (12) can be inserted into the current transformer (35) without removing the power line (12) from the power supply side terminal block (16).

[0058] <<Embodiment 2>> FIG. 3 is a block diagram showing the configuration of the power conversion device according to the second embodiment. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and only the differences will be described.

[0059] As shown in FIG. 3, a switching power supply (28) is provided in the inverter device (20). The switching power supply (28) is connected between the output nodes of the converter circuit (21) and supplies power to the inverter circuit (24) and the control circuit (25).

[0060] Furthermore, the switching power supply (28) is configured to supply power to the control circuit (45) of the active filter device (40) as well.

[0061] As a result, there is no need to separately provide a switching power supply (28) dedicated to the active filter device (40), and the size of the entire device can be reduced and the cost can be reduced.

[0062] <<Other Embodiments>> The above embodiments may have the following configurations.

[0063] In this embodiment, the case where the heat source unit (50) is configured by an outdoor unit equipped with an air-cooling fan (55) has been described, but the present invention is not limited to this form. For example, even when the heat source unit (50) is configured by a large air-conditioning device, such as an air-cooling chiller, a water-cooling chiller, etc., the content of this embodiment can be similarly applied.

[0064] Also, in this embodiment, the inverter device (20) and the active filter device (40) are housed in the same housing (15), but other optional devices may be housed together in this housing (15).

[0065] For example, as other optional devices, a transformer is installed in regions with high power supply voltages such as North America, and an overvoltage suppression device is installed in regions with unstable power supplies such as India. By selecting necessary devices according to the circumstances of countries, regions, etc. and mounting them on the heat source unit (50), a common design globally becomes possible.

Industrial Applicability

[0066] As described above, the present invention Installation of an active filter device for reducing harmonic currents generated in the inverter device is extremely useful and has high industrial applicability because it can obtain a highly practical effect of suppressing costs.

Explanation of Reference Numerals

[0067] 10 Power conversion device 11 AC power supply 12 Power line 13 Electrical wiring 15 Housing 20 Inverter device 21 Converter circuit 24 Inverter circuit 25 Control circuit 28 Switching power supply 30 Noise filter circuit 35 Current transformer 40 Active filter device 41 Switching circuit 42 Capacitor 43 Carrier Filter 44 Link Reactor 45 Control Circuit 52 Compressor 55 Air Cooling Fan

Claims

1. A heat source unit comprising a power conversion device (10) having a housing (15) and an inverter device (20) housed in the housing (15), and a compressor (52) connected to the inverter device (20) via an electrical wiring (13), wherein the compressor (52) is disposed within a main body portion (51) of the heat source unit, the housing (15) is disposed within the main body portion (51), the inverter device (20) has a converter circuit (21) that rectifies AC power from an AC power source (11) into DC power, and an inverter circuit (24) that converts the output power of the converter circuit (21) into AC power of a predetermined frequency, and includes a noise filter circuit (30) connected to a power line (12) connecting the AC power source (11) and the converter circuit (21), within the housing (15), an active filter device (40) that is connected in parallel between the noise filter circuit (30) and the converter circuit (21) in the power line (12) to reduce harmonic current flowing out from the inverter device (20), and other optional devices are housed, the optional device is a transformer, characterized by the heat source unit.

2. A heat source unit comprising a power conversion device (10) having a housing (15) and an inverter device (20) housed in the housing (15), and a compressor (52) connected to the inverter device (20) via an electrical wiring (13), wherein the compressor (52) is disposed within a main body portion (51) of the heat source unit, the housing (15) is disposed within the main body portion (51), the inverter device (20) has a converter circuit (21) that rectifies AC power from an AC power source (11) into DC power, and an inverter circuit (24) that converts the output power of the converter circuit (21) into AC power of a predetermined frequency, and includes a noise filter circuit (30) connected to a power line (12) connecting the AC power source (11) and the converter circuit (21), Inside the housing (15), an active filter device (40) that is connected in parallel between the noise filter circuit (30) and the converter circuit (21) in the power line (12) to reduce the harmonic current flowing out from the inverter device (20), and other optional devices are housed. The optional device is a heat source unit characterized by being an overvoltage suppression device.

3. A heat source unit comprising a power conversion device (10) having a housing (15) and an inverter device (20) housed in the housing (15), and a compressor (52) connected to the inverter device (20) via an electrical wiring (13), The compressor (52) is disposed inside the main body (51) of the heat source unit. The housing (15) is disposed inside the main body (51). The inverter device (20) has a converter circuit (21) that rectifies AC power from an AC power source (11) into DC power, and an inverter circuit (24) that converts the output power of the converter circuit (21) into AC power of a predetermined frequency. It includes a noise filter circuit (30) connected to a power line (12) connecting the AC power source (11) and the converter circuit (21). Inside the housing (15), an active filter device (40) that is connected in parallel between the noise filter circuit (30) and the converter circuit (21) in the power line (12) to reduce the harmonic current flowing out from the inverter device (20), and other optional devices are housed. An air-cooling fan (55) is disposed outside the housing (15). The inverter device (20) is disposed below the air-cooling fan (55) inside the housing (15). A heat source unit, characterized in that the noise filter circuit (30) and the active filter device (40) are disposed in parallel below the inverter device (20) inside the housing (15).

4. A heat source unit comprising a power conversion device (10) having a housing (15) and an inverter device (20) housed in the housing (15), and a compressor (52) connected to the inverter device (20) via an electrical wiring (13), wherein the compressor (52) is disposed in a main body portion (51) of the heat source unit, wherein the housing (15) is disposed in the main body portion (51), wherein the inverter device (20) has a converter circuit (21) that rectifies AC power of an AC power source (11) into DC power, and an inverter circuit (24) that converts the output power of the converter circuit (21) into AC power of a predetermined frequency, and a noise filter circuit (30) connected to a power line (12) connecting the AC power source (11) and the converter circuit (21), wherein an active filter device (40) that reduces harmonic current flowing out from the inverter device (20) and other optional devices are housed in the housing (15) in parallel connection between the noise filter circuit (30) and the converter circuit (21) in the power line (12), wherein a connection port of the electrical wiring (13) is provided above the compressor (52), wherein the inverter device (20) is disposed above the compressor (52) in the housing (15), and wherein the electrical wiring (13) is routed upward from the lower side of the inverter device (20) above the compressor (52) and connected to the connection port of the compressor (52).

5. In any one of Claims 1 to 4, comprising a current transformer (35) that detects a current flowing through the power line (12), The heat source unit is characterized in that the current transformer (35) has a split core that enables the operation of inserting the power line (12) through the current transformer (35) with the power line (12) connected to the noise filter circuit (30) and the inverter device (20).

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