CN115885442B - Air conditioner - Google Patents
Air conditioner Download PDFInfo
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- CN115885442B CN115885442B CN202080101573.7A CN202080101573A CN115885442B CN 115885442 B CN115885442 B CN 115885442B CN 202080101573 A CN202080101573 A CN 202080101573A CN 115885442 B CN115885442 B CN 115885442B
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- Prior art keywords
- air conditioner
- power supply
- inductor
- load
- diode
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/88—Electrical aspects, e.g. circuits
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for DC mains or DC distribution networks
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Air Conditioning Control Device (AREA)
Abstract
The present invention relates to an air conditioner which is connected to a DC power supply, the DC power supply is connected to a plurality of systems which are arranged in parallel, the air conditioner is arranged in a1 st system of the plurality of systems, the air conditioner comprises a1 st load which consumes power, a1 st capacitor which is connected in parallel to the 1 st load and stores power supplied to the 1 st load when the DC power supply fails, a1 st inductor which is connected in series with a1 st positive current path which connects the positive side of the DC power supply and the 1 st load, and suppresses surge current generated when the power supply voltage of the DC power supply rises, a1 st diode which is connected in anti-parallel to the 1 st inductor and returns current flowing by back electromotive force generated by the 1 st inductor, and a 2 nd diode which is connected in anti-parallel to the 1 st capacitor and bypasses a part of current flowing toward the 1 st system by the back electromotive force generated by the 2 nd inductor, the 2 nd inductor being arranged in a 2 nd system which is different from the 1 st system of the plurality of systems.
Description
Technical Field
The present disclosure relates to an air conditioner, and more particularly, to an air conditioner disposed in a power supply system having a plurality of systems.
Background
In recent years, the demand for data centers has become high for disaster countermeasures and stable system operation. The data center is a general term for facilities and buildings for safely storing and operating servers. A server such as a mobile telephone exchange is provided in the data center. The data center has a structure for resisting disasters such as earthquake, and is firm in information safety. Thus, for many businesses, keeping servers in a data center is a greater advantage than setting servers in the company.
In a data center, cooling operation is required throughout the day in order to suppress a temperature rise of a server. In addition, although an air conditioner is generally used by being connected to an ac power source such as a commercial power source, in recent years, an air conditioner powered by dc has been developed.
In dc power supply, a load is supplied with dc voltage from a power supply side. However, in the conventional data center and the like, since ac power is supplied, the following processes (1) to (4) are performed, and power is supplied from an ac power source to a load.
(1) The power supply device provided in the data center converts an ac voltage distributed from an ac power source such as a commercial power source into a dc voltage. In this case, a battery, a solar power generation device, and the like are connected in parallel in the dc system through which the converted dc current flows.
(2) Then, in the power supply device, the dc voltage is converted again into an ac voltage, and the ac voltage is supplied to each load such as an air conditioner.
(3) In each load, an ac voltage from a power supply device is converted into a dc voltage.
(4) Further, in each load, the dc voltage is converted into the ac voltage again in order to drive a motor of a device such as a compressor provided in each load.
Here, if the conversion process from the dc voltage to the ac voltage in the power supply device of (2) can be reduced, the conversion loss can be reduced. Therefore, the dc power supply system capable of reducing the processing of (2) is particularly effective for a data center or the like that consumes a large amount of power. In the dc power supply system, since the load is supplied with dc Voltage from the power supply device, no Ripple Voltage (Ripple Voltage) is present, and a stable dc Voltage can be supplied.
Further, even when a power failure occurs in the commercial power supply, it is desirable that the load continuously operates. In particular, in an air conditioner operated in a data center, high reliability is required to continuously operate even when an instantaneous power failure occurs. For this reason, such air conditioners require stored energy in preparation for the occurrence of an instantaneous power outage. By this energy, electric power can be continuously supplied to each device such as a compressor and a fan motor provided in the air conditioner. For this purpose, an electrolytic capacitor having a capacity capable of storing electric power required for continuous operation of each device is provided between a positive electrode (P) and a negative electrode (N) of a DC circuit in an air conditioner. Further, when the power supply is turned on and when the power supply voltage increases, an excessive surge current is generated in the electrolytic capacitor, and therefore, an inductor is disposed as a countermeasure against the surge current.
In a dc power supply system having a plurality of systems, when the upper-level blocker is turned off during operation of each system device in a state where each system blocker is turned on, a counter electromotive force is generated by self-induction of an inductor in each system device, and there is a problem that energy thereof affects between systems.
For this reason, in the conventional dc blocking circuit, diodes as rectifying elements are connected in anti-parallel to the inductor, thereby suppressing the influence of back electromotive force generated by self-induction of the inductor on other systems. Further, the influence from other systems is suppressed by providing an anti-reverse diode (for example, refer to patent document 1).
The conventional dc current blocking circuit described in patent document 1 is provided with a power storage circuit including a plurality of capacitors. One end of the power storage circuit is connected with the positive DC current path, and the other end of the power storage circuit is connected with the negative DC current path. A fuse serving as a fuse block is connected in series to the rear stage of the input terminal of the positive dc current path. The parallel connection circuit described above in which an inductor and a diode are connected in series between the power storage circuit and the fuse. Further, an anti-reverse diode is connected to the rear stage of the input terminal of the negative dc current path in the same direction as the current path.
In the conventional dc blocking circuit described in patent document 1, since back electromotive force generated by self-induction of the inductor flows back in a closed circuit of the inductor and the diode, influence on other systems is suppressed. In addition, the influence from other systems is suppressed by the reverse flow prevention diode.
Patent document 1 Japanese patent application laid-open No. 2010-153368
However, in the conventional dc current blocking circuit described in patent document 1, since the backflow prevention diode is used, there is a problem in that a loss due to the diode occurs in a stable state.
In patent document 1, there is no intention to provide a dc blocking circuit for an air conditioner. In patent document 1, there is no intention to provide a dc blocking circuit for an air conditioner provided in a data center. Since the data center consumes a large amount of power, there is a problem in that the loss in a steady state increases.
In patent document 1, in order to reduce the loss, it is considered to delete the reverse flow preventing diode. The direct current blocking circuit without the anti-reverse diode is connected to a direct current power supply system formed by connecting a plurality of systems. In this case, if the upper potential breaker shared by the systems is turned off during operation of the system devices in a state where the system breakers are turned on, the upper potential breaker may be affected by the counter electromotive force generated by the inductors of the other system devices, and the polar element such as the electrolytic capacitor may be broken. Therefore, in patent document 1, the reverse flow preventing diode cannot be eliminated.
Disclosure of Invention
The present disclosure has been made to solve the above-described problems, and an object of the present disclosure is to provide an air conditioner capable of reducing loss in a steady state, suppressing influence of back electromotive force of an inductor on other systems, and suppressing influence of back electromotive force from other systems.
An air conditioner according to the present disclosure is connected to a direct current power supply, the direct current power supply being connected to a plurality of systems provided in parallel, the air conditioner being disposed in a1 st system among the plurality of systems, the air conditioner including a1 st load that consumes power, a1 st capacitor that is connected in parallel to the 1 st load and stores power supplied to the 1 st load when a power failure occurs in the direct current power supply, a1 st inductor that is connected in series to a1 st positive current path that connects a positive side of the direct current power supply to the 1 st load, and that suppresses a surge current generated when a power supply voltage of the direct current power supply increases, a1 st diode that is connected in antiparallel to the 1 st inductor and that returns a current flowing by a counter electromotive force generated by the 1 st inductor, and a2 nd diode that is connected in antiparallel to the 1 st capacitor and that bypasses a part of a current flowing to the 1 st system by a counter electromotive force generated by the 2 nd inductor, the 2 nd inductor being provided in the plurality of systems different from the 1 st system.
According to the air conditioner of the present disclosure, it is possible to reduce loss in a steady state, suppress the influence of back electromotive force of an inductor on other systems, and suppress the influence of back electromotive force from other systems.
Drawings
Fig. 1 is a perspective view showing an example of a configuration of a data center 100 provided with an air conditioner 1 according to embodiment 1.
Fig. 2 is a configuration diagram showing a configuration of a dc power supply system 200 provided with the air conditioner 1 according to embodiment 1.
Fig. 3 is a configuration diagram showing a configuration of a dc power supply system 200 provided with an air conditioner 1A according to embodiment 2.
Fig. 4 is a block diagram showing a modification of the air conditioner 1A according to embodiment 2.
Fig. 5 is a configuration diagram showing a configuration of a dc power supply system 200 provided with an air conditioner 1C according to embodiment 3.
Fig. 6 is a block diagram showing a configuration of a modification of the dc power supply system 200 provided with the air conditioner 1D according to embodiment 3.
Detailed Description
Embodiments of an air conditioner according to the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to the following embodiments, and various modifications can be made without departing from the gist of the present disclosure. The present disclosure includes all combinations of combinable structures among the structures shown in the following embodiments and modifications thereof. In the drawings, structures denoted by the same reference numerals are the same or corresponding structures, and are common throughout the specification. In the drawings, the relative dimensional relationship, shape, and the like of the structural members may be different from the actual ones.
Embodiment 1
The air conditioner 1 according to embodiment 1 is, for example, a direct current power supply compatible air conditioner provided in a data center. Fig. 1 is a perspective view showing an example of a configuration of a data center 100 provided with an air conditioner 1 according to embodiment 1. Fig. 1 is a simplified example of the data center 100, and the structure of the data center 100 is not limited thereto.
[ Structure of data center 100 ]
As shown in fig. 1, a server room 101 is provided in a data center 100. An air conditioner 1 is provided in the server room 101. The air conditioner 1 includes an indoor unit 1a and an outdoor unit 1b. The indoor unit 1a is disposed in the server room 101, and the outdoor unit 1b is disposed outside the server room 101. The outdoor unit 1b is installed outdoors such as on a roof of a building. The indoor unit 1a and the outdoor unit 1b are connected via a refrigerant pipe 125. In fig. 1, two air conditioners 1 are provided in the server room 101, but the number of air conditioners 1 may be one or three or more. The air conditioner 1 cools the indoor space of the server room 101. In the server room 101, cooling operation is required throughout the day in order to suppress an increase in temperature of the servers 7 installed in the server room 101. Further, even when the dc power supply 20 has an instantaneous power failure, the operation of the air conditioner 1 needs to be continued.
Further, as shown in fig. 1, a power supply device 2 is provided. The power supply device 2 may be provided outside the server room 101, or may be provided inside the server room 101. The installation position of the power supply device 2 is not particularly limited. In fig. 1, one power supply device 2 is provided, but the number of power supply devices 2 may be two or more. The power supply device 2 is connected to the air conditioner 1 and the server 7, and supplies electric power to the air conditioner 1 and the server 7.
Further, a plurality of server racks 3 are provided in the server room 101. The server racks 3 house servers 7. The server rack 3 is also referred to as a housing rack. The server rack 3 has an earthquake-resistant construction and heat dissipation performance. The server racks 3 are arranged side by side in a column formation. In the example of fig. 1, the server racks 3 are arranged in four rows, but the number of rows is not limited to this. A certain gap is arranged between the columns. Since the cool air from the air conditioner 1 flows through the space, the servers 7 in the server rack 3 are efficiently cooled.
As shown in fig. 1, an operation room 102 is provided in the data center 100. A plurality of terminal apparatuses 4 are provided in the operation room 102. In the operation room 102, an operator is resident in a 24-hour system, for example, and monitors the data center 100 and performs an operation.
The data center 100 is provided with an in-out management system 5 for managing the entry and exit of the server room 101 and the operation room 102. In the data center 100, security checks are performed a plurality of times from the entrance of the building to the server room 101 by the entrance/exit management system 5. The room entrance/exit management system 5 includes, for example, a reception place, a security gate, a monitoring camera, and a biometric authentication system.
Further, a double floor 6 is provided in the server room 101 and the operation room 102 of the data center 100. The double floor 6 is composed of two floors 6a and 6 b. The laying of network wiring and the installation of various devices between the floors 6a and 6b are possible. The cooling air from the air conditioner 1 is sent between the floors 6a and 6b, and thus the server 7 can be cooled from the floors. The double floor 6 constitutes an air blowing unit for blowing cool air from the air conditioner 1. The floor 6a and 6b constituting the double floor 6 are, for example, metal plates made of aluminum. Further, a mesh-like discharge port may be provided in at least a part of the upper floor 6 a. In this case, since the cooling air can be directly supplied from the floor to the server 7, the cooling efficiency is further improved. Although not shown in fig. 1, the ceiling of the data center 100 may be a double-layered ceiling for the same purpose as the double-layered floor 6. In this case, the double ceiling constitutes the air blowing portion of the air conditioner 1, similarly to the double floor 6.
[ DC power supply System 200]
Fig. 2 is a configuration diagram showing a configuration of a dc power supply system 200 provided with the air conditioner 1 according to embodiment 1. As shown in fig. 2, the dc power supply system 200 has a plurality of systems. In general, the term "system" refers to the entire apparatus from power supply to power consumption. Here, as shown in fig. 2, the following 2 nd blocker 41 to the air conditioner 1 are referred to as "1 st system", and the following 3 rd blocker 42 to the 2 nd system device 30 are referred to as "2 nd system". The 1 st system is provided with the air conditioner 1 according to embodiment 1 as the 1 st system equipment disposed in the 1 st machine. The 2 nd system is provided with a2 nd system device 30. The air conditioner 1 is a direct current power supply compatible air conditioner. In the example of fig. 2, the number of systems is two, but the number of systems may be 3 or more.
The dc power supply system 200 is connected to the power supply device 2 shown in fig. 1. The power supply device 2 is provided with a dc power supply 20 shown in fig. 2. The dc power supply system 200 is supplied with electric power by a dc voltage from the dc power supply 20. As shown in fig. 2, the dc power supply system 200 has a1 st blocker 40, a2 nd blocker 41, and a 3 rd blocker 42. The 1 st blocker 40 is connected to the dc power supply 20. The 2 nd blocker 41 is a1 st system blocker provided with respect to the 1 st system. The 2 nd blocker 41 is connected in series between the 1 st blocker 40 and the air conditioner 1. On the other hand, the 3 rd blocker 42 is a2 nd system blocker provided with respect to the 2 nd system. The 3 rd blocker 42 is connected in series between the 1 st blocker 40 and the 2 nd system device 30.
The 1 st blocker 40 is an upper steric blocker of the 2 nd blocker 41 and the 3 rd blocker 42. That is, the 2 nd blocker 41 and the 3 rd blocker 42 are connected to the rear stage of the 1 st blocker 40. The 1 st blocker 40 is provided in common with the 2 nd blocker 41 and the 3 rd blocker 42. The 2 nd blocker 41 and the 3 rd blocker 42 are connected in parallel to the dc power supply 20 via the 1 st blocker 40.
As shown in fig. 2, the positive electrode side of the dc power supply 20 is connected to the positive electrode current path 21, and the negative electrode side of the dc power supply 20 is connected to the negative electrode current path 22. The positive electrode current path 21 is branched into two at a branch point 23. One of the branches is a 1 st positive electrode current path 10 described later, and the other branch is a2 nd positive electrode current path 31 described later. The negative electrode current path 22 is branched into two at a branch point 24. One of the branches is a 1 st negative electrode current path 11 described later, and the other branch is a2 nd negative electrode current path 32 described later. In fig. 2, only the 1 st system provided with the air conditioner 1 and the 2 nd system provided with the 2 nd system device 30 are shown among the plurality of systems connected to the dc power supply 20. For this reason, the case where the positive electrode current path 21 and the negative electrode current path 22 are branched into two at the branching points 23 and 24 has been described. However, the present invention is not limited to this case, and when the dc power supply system 200 is provided with N systems, the positive electrode current path 21 and the negative electrode current path 22 are branched into N at the branching points 23 and 24, respectively.
[ Air conditioner 1]
As described above, the air conditioner 1 is a direct current power supply compatible air conditioner. The air conditioner 1 is supplied with dc power from the dc power supply 20. As shown in fig. 2, the air conditioner 1 is provided with a1 st positive current path 10 and a1 st negative current path 11. The air conditioner 1 is provided with a1 st inductor L11, a1 st capacitor C11, a1 st diode D11, a2 nd diode D12, and a1 st load 12.
[ 1 St Positive electrode current path 10]
The 1 st positive electrode current path 10 is connected to a positive electrode current path 21 connected to the positive electrode side of the dc power supply 20 via a1 st blocking device 40 and a2 nd blocking device 41. The 1 st positive current path 10 electrically connects the positive side of the dc power supply 20 to the 1 st load 12.
[ 1 St negative electrode current path 11]
The 1 st negative electrode current path 11 is connected to the negative electrode current path 22 connected to the negative electrode side of the dc power supply 20 via the 1 st blocking device 40 and the 2 nd blocking device 41. The 1 st negative electrode current path 11 electrically connects the negative electrode side of the dc power supply 20 to the 1 st load 12.
[ 1 St inductor L11]
The 1 st inductor L11 is connected in series with the 1 st positive current path 10. That is, as shown in fig. 2, the 1 st inductor L11 is inserted in series with respect to the 1 st positive current path 10. The 1 st inductor L11 is provided as a countermeasure against the surge current of the 1 st capacitor C11. When the dc power supply 20 is turned on and the power supply voltage increases, an excessive surge current is generated in the 1 st capacitor C11. The 1 st inductor L11 suppresses the surge current flowing into the 1 st capacitor C11. That is, the reactance due to the inductance of the 1 st inductor L11 suppresses the surge current to the 1 st capacitor C11 that does not store electric charge.
[ Capacitor C11 of 1]
The 1 st capacitor C11 is provided in the rear stage of the 1 st inductor L11. The 1 st capacitor C11 has its positive electrode side connected to the 1 st positive electrode current path 10, and the 1 st capacitor C11 has its negative electrode side connected to the 1 st negative electrode current path 11. The 1 st capacitor C11 is, for example, an electrolytic capacitor. The 1 st capacitor C11 stores electric power supplied to the 1 st load 12 at the time of power failure of the dc power supply 20 such as an instantaneous power failure. The 1 st capacitor C11 has a capacity capable of storing electric power required for continuous operation of each device such as a compressor provided in the air conditioner 1 at the time of power failure of the dc power supply 20.
[ Diode 1D 11]
The 1 st diode D11 is connected in antiparallel with the 1 st inductor L11. That is, the cathode of the 1 st diode D11 is connected to the 1 st terminal of the 1 st inductor L11 on the dc power supply 20 side, and the anode of the 1 st diode D11 is connected to the 2 nd terminal of the 1 st inductor L11 on the 1 st load 12 side. The 1 st diode D11 prevents the influence of the counter electromotive force V L11 from being given to other systems when the counter electromotive force V L11 of the 1 st inductor L11 is generated. In the dc power supply system 200 shown in fig. 2, when the 1 st blocker 40 is turned off by an overcurrent blocking operation or a manual operation due to occurrence of a short-circuit accident or the like between the 1 st blocker 40 and the 2 nd blocker 41 or between the 1 st blocker 40 and the 3 rd blocker 42 during operation of the air conditioner 1 and the 2 nd system device 30, a counter electromotive force V L11 is generated due to self-induction of the 1 st inductor L11. At this time, the current flowing through the counter electromotive force V L11 flows back through the closed circuit formed by the 1 st inductor L11 and the 1 st diode D11. This prevents the current from flowing into the 2 nd system device 30.
[ Diode 2D 12]
The 2 nd diode D12 is connected in anti-parallel with the 1 st capacitor C11. The cathode of the 2 nd diode D12 is connected to the positive electrode side of the 1 st capacitor C11 through the 1 st positive electrode current path 10, and the anode of the 2 nd diode D12 is connected to the negative electrode side of the 1 st capacitor C11 through the 1 st negative electrode current path 11. When the counter electromotive force V L21 of the 2 nd inductor L21 described later provided in the 2 nd system device 30 is generated, the 2 nd diode D12 suppresses the influence of the counter electromotive force V L21 on the air conditioner 1. The current flowing by the counter electromotive force V L21 of the 2 nd inductor L21 reversely flows into the 1 st capacitor C11. At this time, by bypassing a part of the current to the 2 nd diode D12, the voltage applied to the 1 st capacitor C11 in the reverse direction is suppressed to the forward voltage drop amount of the 2 nd diode D12. This can prevent breakage of the 1 st capacitor C11.
[ Load 1. 12]
The 1 st load 12 is provided in the rear stage of the 1 st capacitor C11. The 1 st load 12 is a load that consumes electric power. One end of the 1 st load 12 is connected to the 1 st positive current path 10, and the other end of the 1 st load 12 is connected to the 1 st negative current path 11. The 1 st load 12 is, for example, a compressor motor or a fan motor in the refrigerant circuit 120. In the case where the 1 st load 12 is the refrigerant circuit 120, as shown in fig. 2, for example, the compressor 121, the two heat exchangers 122 and 123, and the expansion valve 124 are connected via the refrigerant pipe 125. The refrigerant circuit 120 may further include a four-way valve, an accumulator, and the like, as necessary.
The compressor 121 sucks and compresses a low-pressure gas refrigerant, and discharges the low-pressure gas refrigerant as a high-pressure gas refrigerant. The compressor 121 has a compressor motor 121a that drives the compressor 121. The compressor 121 is, for example, a variable frequency compressor. The inverter compressor can change the amount of refrigerant sent out per unit time by control of an inverter circuit or the like. The inverter circuit controls the driving of the compressor motor 121a.
The two heat exchangers 122 and 123 have heat pipes and fins, respectively. The heat exchangers 122 and 123 are, for example, fin-tube heat exchangers. The heat exchangers 122 and 123 perform heat exchange between the refrigerant flowing inside the heat transfer pipe and the air flowing outside the heat transfer pipe, respectively. The air is blown by a blower fan 126 to the heat exchangers 122 and 123. The heat exchangers 122 and 123 function as evaporators and condensers, respectively. The heat exchanger 122 is disposed in the outdoor unit 1b, and the heat exchanger 123 is disposed in the indoor unit 1a. In the cooling operation of the air conditioner 1, the heat exchanger 122 disposed in the outdoor unit 1b functions as a condenser, and the heat exchanger 123 disposed in the indoor unit 1a functions as an evaporator.
The heat exchangers 122 and 123 are each provided with a blower fan 126. The blower fan 126 blows air to the heat exchangers 122 and 123. The blower fan 126 is composed of a rotary blade 126a and a fan motor 126b that rotates the rotary blade 126 a.
The expansion valve 124 decompresses the inflowing liquid refrigerant by the throttling action and flows out, so that the refrigerant liquefied by the condenser is easily evaporated by the evaporator. Expansion valve 124 is a pressure relief device. Further, the expansion valve 124 adjusts the amount of refrigerant to maintain an appropriate amount of refrigerant corresponding to the load of the evaporator. The expansion valve 124 is constituted by an electronic expansion valve, for example. As shown in fig. 2, the expansion valve 124 is connected between the two heat exchangers 122 and 123 via a refrigerant pipe 125.
[2 Nd System device 30]
As shown in fig. 2, the 2 nd system device 30 is provided with a2 nd positive electrode current path 31, a2 nd negative electrode current path 32, and a2 nd load 33. Further, the 2 nd inductor L21 is provided in the 2 nd system device 30. The 2 nd system device 30 is, for example, an air conditioner, a ventilator, a dehumidifier, or the like.
[ 2 Nd Positive electrode current path 31]
The 2 nd positive electrode current path 31 is connected to the positive electrode current path 21 connected to the positive electrode side of the dc power supply 20 via the 1 st blocking device 40 and the 3 rd blocking device 42. The 2 nd positive current path 31 electrically connects the positive side of the dc power supply 20 to the 2 nd load 33.
[ No. 2 negative electrode current path 32]
The 2 nd negative electrode current path 32 is connected to the negative electrode current path 22 connected to the negative electrode side of the dc power supply 20 via the 1 st blocking device 40 and the 3 rd blocking device 42. The 2 nd negative electrode current path 32 electrically connects the negative electrode side of the dc power supply 20 to the 2 nd load 33.
[ Load 2, 33]
The 2 nd load 33 has one end connected to the 2 nd positive current path 31 and the other end connected to the 2 nd negative current path 32. The 2 nd load 33 is a load consuming electric power. The 2 nd load 33 may be a refrigerant circuit as in the 1 st load 12, but is not particularly limited.
[ Inductor L21 of No. 2]
The 2 nd inductor L21 is connected in series with the 2 nd positive current path 31. That is, as shown in fig. 2, the 2 nd inductor L21 is inserted in series with the 2 nd positive current path 31. Inductor 2L 21 is connected between blocker 42 3 and load 2 33.
[ Operation of DC power supply system 200 and air conditioner 1 ]
Next, with reference to fig. 2, the operation of the dc power supply system 200 and the air conditioner 1 according to embodiment 1 will be described.
In the normal operation, electric power is supplied from the dc power supply 20 to the air conditioner 1 provided in the 1 st system and the 2 nd system equipment 30 provided in the 2 nd system, respectively. The air conditioner 1 and the 2 nd system device 30 are operated by the electric power.
In the dc power supply system 200 of fig. 2, a case will be described in which the 1 st blocking device 40 is turned off during operation of the air conditioner 1 and the 2 nd system device 30. That is, during the supply of electric power to the 1 st loads 12 and 33, the 1 st blocker 40 is turned off due to an overcurrent blocking operation or a manual operation caused by the occurrence of a short-circuit accident or the like between the 1 st blocker 40 and the 2 nd blocker 41 or the 3 rd blocker 42. At this time, the 2 nd blocker 41 and the 3 rd blocker 42 are in an on state.
When the 1 st blocker 40 is turned off, the 1 st inductor L11 of the air conditioner 1 generates a counter electromotive force V L11 in the direction indicated by the arrow in fig. 2 in the 1 st inductor L11 due to self-induction of the 1 st inductor L11. In addition, in the 2 nd system device 30, a counter electromotive force V L21 oriented as indicated by an arrow in fig. 2 is generated in the 2 nd inductor L21 due to self-inductance of the 2 nd inductor L21 as well.
In embodiment 1, a1 st diode D11 connected in antiparallel to the 1 st inductor L11 is provided. Thus, the 1 st inductor L11 and the 1 st diode D11 constitute a closed circuit. Therefore, the current flowing through the counter electromotive force V L11 of the 1 st inductor L11 of the air conditioner 1 flows back in the closed circuit formed by the 1 st inductor L11 and the 1 st diode D11. Therefore, the voltage applied in the reverse direction to the 2 nd system device 30 is suppressed to be less than the voltage drop amount of the 1 st diode D11. Thereby, the influence of the counter electromotive force V L11 of the 1 st inductor L11 of the air conditioner 1 on the 2 nd system device 30 can be suppressed.
In embodiment 1, a2 nd diode D12 connected in antiparallel to the 1 st capacitor C11 is provided. A part of the current flowing through the counter electromotive force V L21 of the 2 nd inductor L21 of the 2 nd system device 30 is bypassed to the 2 nd diode D12 side through the 2 nd diode D12. Therefore, the voltage applied to the 1 st capacitor C11 of the air conditioner 1 in the reverse direction is suppressed to the forward voltage drop amount of the 2 nd diode D12. As a result, the 1 st capacitor C11 can be prevented from being broken.
As described above, in embodiment 1, even if the reverse current prevention diode described in patent document 1 is not provided, the influence of counter electromotive force on other systems can be suppressed. That is, the polar element of the 2 nd system device 30 can be prevented from being damaged by the counter electromotive force V L11 of the 1 st inductor L11 of the air conditioner 1. Further, the polar element of the air conditioner 1 can be prevented from being damaged by the counter electromotive force V L21 of the 2 nd inductor L21 of the 2 nd system device 30. In addition, since the 1 st diode D11 and the 2 nd diode D12 do not flow current in the normal use state, no loss occurs. In this way, in embodiment 1, the reverse flow preventing diode can be reduced, and the loss thereof can be eliminated.
As described above, when the air conditioner 1 according to embodiment 1 is connected to the dc power supply system 200 having a plurality of systems, and the 1 st blocking device 40 connected to the plurality of systems is disconnected during operation of each system device, the following effects (a) to (d) can be obtained.
(A) In the air conditioner 1 according to embodiment 1, the 1 st diode D11 is connected in anti-parallel to the 1 st inductor L11 of the air conditioner 1. The 1 st diode D11 returns a current flowing through the counter electromotive force V L11 generated in the 1 st inductor L11. Therefore, the reverse voltage generated by the counter electromotive force V L11 of the 1 st inductor L11 is not applied to the 2 nd system device 30, and breakage of the polar element in the 2 nd system device 30 can be prevented.
(B) In the air conditioner 1 according to embodiment 1, the 2 nd diode D12 is connected in parallel to the 1 st capacitor C11 of the air conditioner 1. At this time, the cathode of the 2 nd diode D12 is connected to the positive electrode side of the 1 st capacitor C11, and the anode of the 2 nd diode D12 is connected to the negative electrode side of the 1 st capacitor C11. A part of the current flowing toward the air conditioner 1 by the counter electromotive force V L21 generated in the 2 nd inductor L21 of the 2 nd system device 30 is bypassed to the 2 nd diode D12. Therefore, the voltage applied reversely to the 1 st capacitor C11 is suppressed by the 2 nd diode D12. Accordingly, even if a reverse voltage is applied to the air conditioner 1 due to the counter electromotive force V L21 of the 2 nd inductor L21 of the 2 nd system device 30, breakage of the polar element in the air conditioner 1 can be prevented.
(C) Unlike patent document 1, the air conditioner 1 according to embodiment 1 does not use a reverse flow preventing diode, and therefore, loss in a steady state is reduced, and the operation efficiency of the air conditioner 1 can be improved.
(D) The air conditioner 1 according to embodiment 1 is an air conditioner to which a direct current power supply is applied. Therefore, in the power supply device 2, it is not necessary to convert the dc power converted from the ac power into ac again in order to supply the dc power to the dc power-supply-compatible device. Therefore, the conversion loss can be reduced. As a result, the air conditioner 1 according to embodiment 1 is suitable for use in the data center 100 or a large building where power consumption is large. Further, since the air conditioner 1 is supplied with dc power from the dc power supply 20, no ripple voltage is generated, and stable dc voltage can be supplied.
Embodiment 2
Fig. 3 is a configuration diagram showing a configuration of a dc power supply system 200 provided with an air conditioner 1A according to embodiment 2. The difference between fig. 2 and fig. 3 is the structure of the air conditioner 1. Hereinafter, the air conditioner 1 according to embodiment 2 is referred to as an air conditioner 1A, and is distinguished from the air conditioner 1 according to embodiment 1. The difference between the air conditioner 1A of fig. 3 and the air conditioner 1 of fig. 2 will be described. In the air conditioner 1A, a voltage monitor 13, a resistor R11, a switch SW11, and a switch control unit 14 are added to the structure of the air conditioner 1. Other configurations of dc power supply system 200 according to embodiment 2 are similar to those of dc power supply system 200 according to embodiment 1, and therefore, a description thereof will be omitted here. In embodiment 2, the air conditioner 1A is also provided in the data center 100 shown in fig. 1, for example.
[ Voltage monitoring device 13]
The voltage monitoring device 13 is disposed in the air conditioner 1A at a position closest to the dc power supply 20. That is, the voltage monitor 13 is provided in the power supply input unit of the air conditioner 1A. As shown in fig. 3, the voltage monitoring device 13 has one end connected to the 1 st positive current path 10 and the other end connected to the 1 st negative current path 11. The voltage monitoring device 13 always detects and monitors the input voltage from the dc power supply 20 to the air conditioner 1. When detecting that the input voltage is equal to or lower than a preset threshold, the voltage monitoring device 13 transmits a detection signal to the switch control unit 14.
[ Switch SW11]
The switch SW11 is provided at the rear stage of the voltage monitoring device 13 and is connected in series with the 1 st positive current path 10. The switch SW11 is connected between the voltage monitoring device 13 and the 1 st load 12. In the example of fig. 3, the switch SW11 is connected between the voltage monitoring device 13 and the 1 st inductor L11. The switch SW11 is turned off before the power is turned on and turned on after the power is turned on by the control of the switch control unit 14 described later.
Resistor R11
The resistor R11 is connected in parallel with respect to the switch SW 11. The resistor R11, the switch SW11, and the switch control section 14 constitute an inrush current prevention circuit.
[ Switch control section 14]
The switch control unit 14 controls the on and off of the switch SW11 based on the detection result of the voltage monitoring device 13. The switch control unit 14 receives a detection signal from the voltage monitoring device 13. The switch control unit 14 turns the switch SW11 from on to off after a predetermined time elapses from the time when the detection signal is input. The fixed time is a fixed value set in advance. The certain time is described later.
In addition, the positions of the resistor R11 and the switch SW11 and the position of the 1 st inductor L11 may also be interchanged. That is, the resistor R11 and the switch SW11 may be provided in the rear stage of the 1 st inductor L11.
As shown in fig. 4, the 1 st diode D11 may be connected in parallel to a series circuit including the switch SW11 and the 1 st inductor L11 connected in series. That is, one end of the resistor R11 on the dc power supply 20 side may be connected to the cathode of the 1 st diode D11. Fig. 4 is a block diagram showing a modification of the air conditioner 1A according to embodiment 2. Hereinafter, a modified example of the air conditioner 1A according to embodiment 2 will be referred to as an air conditioner 1B, and the air conditioner 1A according to embodiment 2 is distinguished from the modified example. In the air conditioner 1A shown in fig. 3, the cathode of the 1 st diode D11 is connected to the 1 st terminal of the 1 st inductor L11 on the dc power supply 20 side. In contrast, in the air conditioner 1B shown in fig. 4, the cathode of the 1 st diode D11 is connected to one end of the resistor R11 on the dc power supply 20 side. The connection on the anode side of the 1 st diode D11 in the air conditioner 1B of fig. 4 is the same as the air conditioner 1A of fig. 3. Thus, in fig. 4, the 1 st diode D11 is disposed in parallel with respect to the series circuit formed by the switch SW11 and the 1 st inductor L11.
In addition, in both the case of fig. 3 and fig. 4, the resistor R11 and the switch SW11 need to be connected to a position in front of (i.e., on the primary side of) the 1 st capacitor C11.
Operation of dc power supply system 200 and operation of air conditioners 1A and 1B
Next, the operation of the dc power supply system 200 and the operation of the air conditioners 1A and 1B according to embodiment 2 will be described with reference to fig. 3. In the following, for simplicity of explanation, the case of the air conditioner 1A shown in fig. 3 among the air conditioners 1A and 1B will be described by way of example. The operation of the air conditioner 1B is the same as that of the air conditioner 1A, and therefore, a description thereof will be omitted here.
In the normal operation, electric power is supplied from the dc power supply 20 to the air conditioner 1A provided in the 1 st system and the 2 nd system equipment 30 provided in the 2 nd system, respectively. The air conditioner 1A and the 2 nd system device 30 are operated by the electric power.
In the dc power supply system 200 of fig. 3, a case will be described in which the 1 st blocker 40 is turned off due to an overcurrent blocking operation or a manual operation caused by occurrence of a short-circuit accident or the like between the 1 st blocker 40 and the 2 nd blocker 41 or the 3 rd blocker 42 during operation of the air conditioner 1A and the 2 nd system device 30, that is, during supply of electric power to the 1 st load 12 and the 2 nd load 33. At this time, the 2 nd blocker 41 and the 3 rd blocker 42 are in an on state.
When the 1 st interrupter 40 is turned off, the counter electromotive force V L11 is generated in the 1 st inductor L11 by self-induction of the 1 st inductor L11 of the air conditioner 1A, as in embodiment 1. In the 2 nd system device 30, the counter electromotive force V L21 is generated in the 2 nd inductor L21 in the same manner as in embodiment 1 due to self-inductance of the 2 nd inductor L21 of the 2 nd system device 30.
In embodiment 2, as in embodiment 1, a 1 st diode D11 connected in antiparallel to the 1 st inductor L11 is also provided. Therefore, the current flowing through the counter electromotive force V L11 of the 1 st inductor L11 of the air conditioner 1 flows back through the closed circuit formed by the 1 st inductor L11 and the 1 st diode D11. Thereby, the influence of the counter electromotive force V L11 of the 1 st inductor L11 of the air conditioner 1 on the 2 nd system device 30 can be suppressed.
In embodiment 2, a2 nd diode D12 connected in parallel to the 1 st capacitor C11 is also provided as in embodiment 1. A part of the current flowing through the counter electromotive force V L21 of the 2 nd inductor L21 of the 2 nd system device 30 is bypassed to the 2 nd diode D12 side through the 2 nd diode D12. Therefore, the voltage applied to the 1 st capacitor C11 of the air conditioner 1 in the reverse direction is suppressed to be equal to or less than the forward voltage drop amount of the 2 nd diode D12. As a result, the 1 st capacitor C11 can be prevented from being broken.
In embodiment 2, as shown in fig. 3, a voltage monitoring device 13 is provided. The voltage monitor 13 monitors the input voltage of the air conditioner 1A. When detecting that the input voltage is equal to or lower than a preset threshold, the voltage monitoring device 13 transmits a detection signal to the switch control unit 14. When the voltage monitoring device 13 detects a decrease in the input voltage, the switch SW11 needs to be turned from on to off by the switch control unit 14 in order to prevent a surge current at the next power supply input. However, if the switch SW11 is turned off immediately after the voltage reduction is detected by the voltage monitoring device 13, the resistor R11 is provided, so that the impedance of the 1 st positive electrode current path 10 increases. In this case, the 1 st inductor L11 or the 2 nd inductor L21 is required to maintain a current, and an excessive counter electromotive force is generated. As a result, an excessive voltage is applied to the resistor R11, and the resistor R11 may be broken. Therefore, the switch control unit 14 turns off the switch SW11 after a predetermined time elapses after the voltage monitoring device 13 detects the voltage decrease, that is, after the counter electromotive forces V L11 and V L21 of the 1 st and 2 nd inductors L11 and L21 converge. This can suppress the generation of excessive back electromotive force and suppress breakage of the resistor R11. The switch SW11 is turned off when the power is turned on, and is turned on after the power is turned on. Therefore, at the time of power supply, a current flows through the resistor R11, and thus, a surge current to the 1 st capacitor C11 can be suppressed. As described above, in embodiment 2, it is possible to suppress a surge current when the 2 nd blocking device 41 is turned on or when the dc power supply 20 resumes power supply from a power failure, or the like, immediately after the voltage monitor device 13 detects the voltage drop.
The above-described constant time until the energies of the counter electromotive forces V L11 and V L21 converge varies depending on the resistance component, inductance component, capacitance component, current value, and power supply voltage of the entire dc power supply system 200 located downstream of the 1 st interrupter 40. Therefore, it is preferable to measure the predetermined time for each dc power supply system 200 by an experiment or the like and to set the predetermined time in advance in the switch control unit 14.
In the air conditioner 1A installed in the data center 100, only the air conditioner may be connected to the lower side of the 1 st interrupter 40 to configure the dc power supply system 200. In other words, the 2 nd system device 30 may be constituted by an air conditioner. In this case, the air conditioner constituting the 2 nd system device 30 and the air conditioner 1A are often the same type of air conditioner or air conditioners manufactured by the same manufacturing company. Therefore, the resistance component, inductance component, capacitance component, current value, and power supply voltage of the entire dc power supply system 200 located below the 1 st blocker 40 can be easily grasped. In this case, since the characteristic variation between the air conditioners is relatively small, the fixed time until the switch SW11 is turned off can be set to a smaller value, and the next power input can be handled in a shorter time.
As described above, in embodiment 2 as well, since the 1 st diode D11 and the 2 nd diode D12 are provided in the same manner as in embodiment 1, the effects (a) to (D) described above obtained in embodiment 1 can be obtained.
In embodiment 2, since the inrush current prevention circuit including the resistor R11 and the switch SW11 is provided, it is possible to further suppress an inrush current when the power is turned on to the air conditioners 1A and 1B, that is, when the 2 nd blocking device 41 is turned on, when the dc power supply 20 resumes the power supply from the power failure, or the like.
Embodiment 3
Fig. 5 is a configuration diagram showing a configuration of a dc power supply system 200 provided with an air conditioner 1C according to embodiment 3. The difference between fig. 2 and fig. 5 is the structure of the air conditioner 1. Hereinafter, the air conditioner 1 according to embodiment 3 will be referred to as an air conditioner 1C, and the air conditioner 1 according to embodiment 1 is distinguished from the air conditioner 1. The difference between the air conditioner 1C of fig. 5 and the air conditioner 1 of fig. 2 will be described. In the air conditioner 1C, an inverter circuit 15 and a current detection resistor 17 are added to the configuration of the air conditioner 1. In fig. 5, the 1 st load 12 is constituted by a motor 16. Other configurations of the dc power supply system 200 according to embodiment 3 are the same as those of the dc power supply system 200 according to embodiment 1, and therefore, the description thereof will be omitted here. In embodiment 3, the air conditioner 1C is also provided in the data center 100 shown in fig. 1, for example.
[ Motor 16]
The motor 16 is, for example, a compressor motor 121a provided in the compressor 121 of the refrigerant circuit 120 of fig. 2 or a fan motor 126b of the blower fan 126. Although not shown in fig. 5, in embodiment 3, the air conditioner 1C is actually provided with a refrigerant circuit 120 as shown in fig. 2. The entire refrigerant circuit 120 is also a load provided in the air conditioner 1C. However, in embodiment 3, a description will be given by taking as an example a case where either one of the compressor motor 121a of the compressor 121 or the fan motor 126b of the blower fan 126 in the configuration of the air conditioner 1C is taken as the motor 16, and the motor 16 is taken as the load 12 to be driven by the inverter circuit 15.
[ Inverter Circuit 15]
The inverter circuit 15 drives the motor 16. The inverter circuit 15 converts dc power supplied from the dc power supply 20 into 3-phase ac power. The inverter circuit 15 has a plurality of switching elements SW21 to SW26. The switching elements SW21 to SW26 are made of semiconductor elements such as IGBT (Insulated Gate Bipolar Transistor). In the example of fig. 5, the inverter circuit 15 has 6 switching elements SW21 to SW26 bridged. Thus, in the example of fig. 5, the inverter circuit 15 is a three-phase bridge inverter. The inverter circuit 15 converts the dc voltage applied to the inverter circuit 15 into a three-phase ac voltage by switching operations of the 6 switching elements SW21 to SW26, and supplies an ac current of a desired frequency to the motor 16. The 6 switching elements SW21 to SW26 are PWM-controlled by a control device not shown. The switching elements SW21 to SW26 may be made of wide band gap semiconductors.
The switching elements SW21 to SW26 are connected in anti-parallel with the reflux diodes FWD21 to FWD26, respectively. The structure in which the switching element SW21 and the reflux diode FWD21 are connected in anti-parallel is referred to as an arm. In the example of fig. 5, the inverter circuit 15 has 3 arms on the upper side and 3 arms on the lower side. Hereinafter, the upper arm will be referred to as an upper arm, and the lower arm will be referred to as a lower arm. The emitters of the switching elements SW21, SW22 and SW23 of the upper arm and the collectors of the switching elements SW24, SW25 and SW26 of the lower arm are connected in series to constitute the upper and lower arms. The connection point at which the upper arm and the lower arm are connected in series is referred to as the midpoint 18. The midpoints 18 of the 3 upper and lower arms are connected to respective motors 16. Further, 3 upper and lower arms are connected in parallel to form the inverter circuit 15. The collectors of the switching elements SW21, SW22 and SW23 of the upper arm are connected to each other at a connection point 27. Further, the emitters of the switching elements SW24, SW25 and SW26 of the lower arm are connected to each other at a connection point 28.
[ Resistor 17 for Current detection ]
The current detection resistor 17 is provided to detect a value of a current flowing to the inverter circuit 15. The current detection resistor 17 is connected in series between the negative electrode side of the 1 st capacitor C11 and the connection point 28. That is, the current detection resistor 17 is connected in series to the 1 st negative electrode current path 11 between the negative electrode side of the 1 st capacitor C11 and the connection point 28. When a current flows through the current detection resistor 17, a voltage is generated across the current detection resistor 17. By inputting the value of the voltage to a control device, not shown, the control device can detect the value of the current flowing to the inverter circuit 15 based on the value of the voltage. The control device can control the operation of the motor 16 or detect an overcurrent to the inverter circuit 15 by acquiring a current value using the current detection resistor 17. The current detection resistor 17 is connected in series with the 1 st negative electrode current path 11 between the negative electrode side of the 1 st capacitor C11 and the connection point 28, but may be connected in series with the 1 st positive electrode current path 10 between the positive electrode side of the 1 st capacitor C11 and the connection point 27.
[ Operation of DC power supply system 200 and air conditioner 1C ]
Next, with reference to fig. 5, the operation of the dc power supply system 200 and the air conditioner 1C according to embodiment 3 will be described.
In the normal operation, electric power is supplied from the dc power supply 20 to the air conditioner 1C provided in the 1 st system and the 2 nd system equipment 30 provided in the 2 nd system, respectively. The air conditioner 1C and the 2 nd system device 30 are operated by the electric power.
In the dc power supply system 200 of fig. 5, a description will be given of a case where the 1 st interrupter 40 is turned off due to an overcurrent blocking operation or a manual operation caused by occurrence of a short-circuit accident or the like between the 1 st interrupter 40 and the 2 nd interrupter 41 or the 3 rd interrupter 42 during operation of the air conditioner 1C and the 2 nd system device 30, that is, during supply of electric power to the motor 16 and the 2 nd load 33. At this time, the 2 nd blocker 41 and the 3 rd blocker 42 are in an on state.
When the 1 st interrupter 40 is turned off, the counter electromotive force V L11 is generated in the 1 st inductor L11 by self-induction of the 1 st inductor L11 of the air conditioner 1C, as in embodiment 1. In the 2 nd system device 30, the counter electromotive force V L21 is generated in the 2 nd inductor L21 in the same manner as in embodiment 1 due to self-inductance of the 2 nd inductor L21 of the 2 nd system device 30.
In embodiment 3, as in embodiment 1, a1 st diode D11 connected in antiparallel to the 1 st inductor L11 is also provided. Therefore, the current flowing through the counter electromotive force V L11 of the 1 st inductor L11 of the air conditioner 1C flows back through the closed circuit formed by the 1 st inductor L11 and the 1 st diode D11. Thereby, the influence of the counter electromotive force V L11 of the 1 st inductor L11 of the air conditioner 1C on the 2 nd system device 30 can be suppressed.
In embodiment 3, a2 nd diode D12 connected in anti-parallel to the 1 st capacitor C11 is also provided as in embodiment 1. A part of the current flowing through the counter electromotive force V L21 of the 2 nd inductor L21 of the 2 nd system device 30 is bypassed to the 2 nd diode D12 side through the 2 nd diode D12. Therefore, the voltage applied to the 1 st capacitor C11 of the air conditioner 1C in the reverse direction is suppressed to be equal to or less than the forward voltage drop amount of the 2 nd diode D12. As a result, the 1 st capacitor C11 can be prevented from being broken.
In embodiment 3, in the inverter circuit 15, the upper-arm reflux diode FWD21 and the lower-arm reflux diode FWD24 are connected in series. Also, the reflux diode FWD22 of the upper arm is connected in series with the reflux diode FWD25 of the lower arm. In addition, similarly, the reflux diode FWD23 of the upper arm is connected in series with the reflux diode FWD26 of the lower arm.
The case where the counter electromotive force V L21 of the 2 nd inductor L21 is large and an excessive current flows into the air conditioner 1C will be described. As described above, in the inverter circuit 15, the reflux diode FWD21 and the reflux diode FWD24, the reflux diode FWD22 and the reflux diode FWD25, and the reflux diode FWD23 and the reflux diode FWD26 are respectively provided in series. Therefore, the current flowing through the counter electromotive force V L21 mainly flows through the 2 nd diode D12, and the current value flowing through the current detection resistor 17 can be suppressed. This can prevent breakage of the current detection resistor 17.
At this time, the larger the difference between the minimum sum of the forward voltages of the backward pass diode FWD21 and the backward pass diode FWD24, the sum of the forward voltages of the backward pass diode FWD22 and the backward pass diode FWD25, and the sum of the forward voltages of the backward pass diode FWD23 and the backward pass diode FWD26 and the forward voltage of the 2 nd diode D12, the more easily the current flows to the 2 nd diode D12, and the breakage of the current detection resistor 17 is prevented. Therefore, the respective reflux diodes FWD21 to FWD26 may be appropriately determined so that the difference between the sum of the forward voltages of the two reflux diodes included in the respective upper and lower arms and the forward voltage of the 2 nd diode D12 becomes large.
As shown in fig. 6, a plurality of motors 16A and 16B may be provided in the air conditioner. In this case, as described in embodiments 1 and 2 above, the 1 st capacitor C11 for power supply at the time of the instantaneous power failure and the 1 st inductor L11 for suppressing the surge current are provided for each motor drive system provided with the motors 16A and 16B. In this case, the inverter circuit 15 described in embodiment 3 needs to be applied to each motor drive system. Hereinafter, the description will be made in detail.
Fig. 6 is a block diagram showing a configuration of a modification of the dc power supply system 200 provided with the air conditioner 1D according to embodiment 3. The difference between fig. 5 and fig. 6 is the structure of the air conditioner. Hereinafter, the air conditioner according to the modification of embodiment 3 is referred to as an air conditioner 1D, and is distinguished from the air conditioner 1C according to embodiment 3. The difference between the air conditioner 1C of fig. 5 and the air conditioner 1D of fig. 6 will be described. In the air conditioner 1D, as the 1 st load 12, two motors 16A and 16B are provided. The motors 16A and 16B are, for example, a compressor motor 121a provided in the compressor 121 of the refrigerant circuit 120 in fig. 2 or a fan motor 126B of the blower fan 126. Here, for example, the motor 16A is a compressor motor 121a provided in the compressor 121 of the refrigerant circuit 120 of fig. 2, and the motor 16B is a fan motor 126B of the blower fan 126 disposed in the outdoor unit 1B.
In fig. 6, the 1 st positive electrode current path 10 is branched into two at a branching point 25. One of the branches is a1 st branch positive electrode current path 10A, and the other branch is a 2 nd branch positive electrode current path 10B.
Similarly, in fig. 6, the 1 st negative electrode current path 11 is branched into two at a branching point 26. One of the branches is a1 st branch negative electrode current path 11A, and the other branch is a 2 nd branch negative electrode current path 11B.
Hereinafter, a system provided with the 1 st branch positive current path 10A and the 1 st branch negative current path 11A is referred to as a 1 st motor drive system. In the 1 st motor drive system, a motor 16A is provided as the 1 st load 12. The structure of the 1 st motor driving system is the same as that of the air conditioner 1C of fig. 5, and therefore, a description thereof will be omitted here.
Hereinafter, a system provided with the 2 nd branch positive current path 10B and the 2 nd branch negative current path 11B is referred to as a2 nd motor driving system. In the 2 nd motor drive system, a motor 16B is provided as the 1 st load 12. The structure of the 2 nd motor driving system is substantially the same as that of the 1 st motor driving system. Therefore, the structure of the 2 nd motor driving system is the same as that of the air conditioner 1C of fig. 5.
As described above, when a plurality of motors 16A and 16B are provided in the air conditioner 1D, the 1 st capacitor C11 and the 1 st inductor L11 described in embodiment 1 are provided for the respective motors 16A and 16B, as shown in fig. 6. This achieves the same effects as those of embodiment 1 described above. In this case, the inverter circuit 15 described in embodiment 3 is applied to each motor drive system. This achieves the same effects as those of embodiment 3 described above.
In fig. 6, when the motors 16A and 16B constituting the air conditioner 1D are different motors, the 1 st diode D11 on the motor side that is more required to be continuously operated is selected as a diode having high resistance to the peak of the current. For example, when one of the motor 16A and the motor 16B is a compressor motor and the other is a fan motor in the case where the air conditioner 1D is an indoor unit, the 1 st diode D11 on the fan motor side is selected as the diode having high resistance to the peak current. Thus, even if a short-circuit failure occurs in the 1 st diode D11 on the compressor motor side due to the generation of back electromotive force of other systems, the 1 st diode D11 on the fan motor side may not be broken. In this case, the air conditioner can continuously perform the air blowing operation, and the temperature rise in the server room can be reduced.
Although the air conditioner 1D is shown here as being constituted by 2 motors, i.e., the motor 16A and the motor 16B, it may be constituted by 3 or more motors. For example, 3 motors are mounted in the outdoor unit, wherein 1 motor is a compressor motor and the other 2 motors are fan motors. At this time, the 1 st diode D11 on the compressor motor side and the 1 st diode D11 on the fan motor side of the other 2 are selected as diodes having high resistance to the current peak. Accordingly, even if the 1 st diode D11 on the fan motor side having low endurance is short-circuited due to the generation of back electromotive force of other systems, the 1 st diode D11 on the compressor and the 1 st fan motor side may not be broken, and thus the air conditioner can continue the cooling operation, and the temperature rise of the server room can be reduced.
As described above, also in embodiment 3 and its modification, the 1 st diode D11 and the 2 nd diode D12 are provided in the same manner as in embodiment 1, and therefore the effects (a) to (D) obtained in embodiment 1 can be obtained.
In embodiment 3 and its modifications, when the counter electromotive force V L21 of the 2 nd inductor L21 is large, the current flowing through the counter electromotive force V L21 mainly flows through the 2 nd diode D12. This can suppress the current value flowing through the current detection resistor 17 and the inverter circuit 15. Therefore, breakage of the current detection resistor 17 and breakage of each element in the inverter circuit 15 can be prevented. In this way, in embodiment 3 and its modifications, it is possible to prevent damage due to reverse voltage application of each element on the 1 st load 12 side of the rear stage of the 2 nd inductor L21 and damage due to overcurrent.
In the above embodiments 1 to 3, the case where the air conditioners 1 and 1a to 1d are provided in the data center 100 will be described. However, this is not limited to this case. The air conditioners 1 and 1a to 1d according to embodiments 1 to 3 are applicable to any indoor space as long as they are indoor spaces that require continuous operation even when an instantaneous power failure occurs. Examples of such indoor space include a freezer warehouse.
Description of the reference numerals
Air conditioner; air conditioner; the electric power supply system comprises an air conditioner, a first-class indoor unit, a second-class outdoor unit, a first-class outdoor unit, a second-class outdoor unit, a first-class power supply device, a third-class power supply device, a first-class power supply device, a second-class power supply device, a third-class power supply device, a fourth-class power supply device, a third-class power supply device, a fourth-class power supply device, a fifth-class power supply device, a third-class power supply device, a fourth-class power supply device, a fifth-class power supply device, a third-class power supply device, a fourth-class power supply device, a third-class power supply device, a fifth-class power supply device and a, a third-class and a high-class, and a high-class, and a 2, and a.2, and a.they are 2, and a.are regarded.are regarded to and 2, and are 2 and, and are regarded and, and are and, and are and are and the electric motor for fan is configured to be a fan, and the fan is configured to be a fan, a motor for fan, a dc power supply system, a capacitor of c11, a diode of d11, a diode of c1, a diode of d12, a diode of d2, a diode of fwd21, a diode of return, a diode of fwd22, a diode of fwd23, a diode of return, fwd24, a diode of fwd25, a diode of return, fwd26, a diode of return, an inductor of l11, a capacitor of c1, an inductor of d21, a resistor of c 2, a switch of r11, a switch of s 21, a switch of s 22, a switch of s 23, a switch of s 24, a switch of s 25, a switch of s 26, a switch of s L11, a back electromotive force, and a back electromotive force V L21.
Claims (11)
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| PCT/JP2020/028318 WO2022018831A1 (en) | 2020-07-21 | 2020-07-21 | Air conditioner |
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| CN115885442B true CN115885442B (en) | 2024-11-29 |
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| CN101073198A (en) * | 2004-12-09 | 2007-11-14 | 大金工业株式会社 | Multi-phase current supplying circuit, driving apparatus, compressor, and air conditioner |
| CN102801378A (en) * | 2011-05-27 | 2012-11-28 | 日立空调·家用电器株式会社 | Motor control device and air conditioner possessing same |
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| JP2003046357A (en) * | 2001-07-26 | 2003-02-14 | Sharp Corp | High impedance circuit |
| JP2009072061A (en) * | 2003-05-28 | 2009-04-02 | Audio Labo Corp | Unit for preventing counter-electromotive force |
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| JP2010153368A (en) * | 2008-11-21 | 2010-07-08 | Ntt Data Intellilink Corp | Direct current interruption assist circuit, direct overcurrent interrupting circuit, direct current interrupting circuit, and incoming direct current preventing circuit |
| KR100902035B1 (en) * | 2009-03-06 | 2009-06-15 | 주식회사 누리플랜 | LED fluorescent lamp lighting control device |
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| KR101809944B1 (en) * | 2015-12-02 | 2017-12-18 | 공주대학교 산학협력단 | Arcless DC Circuit Breaker using Semiconductor Switch |
| JP2020014326A (en) * | 2018-07-19 | 2020-01-23 | 三菱電機株式会社 | Electric power conversion device |
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2020
- 2020-07-21 WO PCT/JP2020/028318 patent/WO2022018831A1/en active Application Filing
- 2020-07-21 JP JP2022538534A patent/JP7262676B2/en active Active
- 2020-07-21 CN CN202080101573.7A patent/CN115885442B/en active Active
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| CN101073198A (en) * | 2004-12-09 | 2007-11-14 | 大金工业株式会社 | Multi-phase current supplying circuit, driving apparatus, compressor, and air conditioner |
| CN102801378A (en) * | 2011-05-27 | 2012-11-28 | 日立空调·家用电器株式会社 | Motor control device and air conditioner possessing same |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2022018831A1 (en) | 2022-01-27 |
| JPWO2022018831A1 (en) | 2022-01-27 |
| CN115885442A (en) | 2023-03-31 |
| JP7262676B2 (en) | 2023-04-21 |
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