Inverter device and inverter cooling method

Abstract

To realize reduction in the capacity of emergency batteries when inverters connected in parallel are provided.SOLUTION: N inverter units connected in parallel are applied to an inverter device. Each of the N inverter units has M (M is an integer equal to or more than 2) cooling fans arranged, a first power supply circuit 22 supplying driving power supply to a first group of cooling fans among M cooling fans arranged per inverter unit, a second power supply circuit 23 supplying the driving power supply to a second group of cooling fans among the M cooling fans arranged per inverter unit, and a battery 24 for interruption of electric service supplying power supply to the second power supply circuit at the time of interruption of electric service.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an inverter device and an inverter cooling method. [Background technology]

[0002] Elevators and other elevators use AC motors as their power source. To control the operating state of AC motors, an inverter is used to convert the voltage and frequency of the power source. For example, in the case of an elevator installed in a building, the three-phase AC power source supplied by the power company is converted in voltage and frequency by an inverter before being supplied to the AC motor that constitutes the hoist. When converting the voltage and frequency of a three-phase AC power supply using an inverter, specifically, the three-phase AC power supply is converted into DC power supply using a converter, and the converted DC power supply is converted into AC power supply of the desired voltage and frequency using an inverter. Here, the converter and the inverter can have the same basic configuration, in which case, the only difference is that the operating direction is reversed. In the following explanation, when the word "inverter" is used, it also includes the converter, unless a special distinction is made.

[0003] When using inverters to control the power supply of elevators and other lifts, multiple inverters are connected in parallel depending on the required power supply capacity, and the multiple inverters perform processing simultaneously. That is, inverters are made up of semiconductor switches such as IGBTs (Insulated Gate Bipolar Transistors), and since there is a limit to the current and voltage that can pass through a single semiconductor switch, multiple inverters are connected in parallel to ensure the required power supply capacity. For example, to configure an inverter with an output of 200 kW, four inverters, each with an output of 50 kW, are connected in parallel to ensure 200 kW.

[0004] However, the semiconductor switches in an inverter generate a large amount of heat during operation, and therefore the inverter must be provided with a cooling device. In the case of a configuration in which multiple inverters are connected in parallel as described above, each inverter must have a cooling device such as a cooling fan. Patent Document 1 describes a cooling device for a power conversion device, and describes a technique for varying the amount of cooling air generated by a cooling fan depending on the output current and ambient temperature conditions of the power conversion device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-185384 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, elevators and other lifting machines are equipped with emergency batteries so that they can perform a minimum of rescue operations even during a power outage. Therefore, even during a power outage, the inverter operates with power from the battery when performing rescue operations. Furthermore, when the inverter is operated using power from an emergency battery, it is necessary to operate the cooling fan to prevent damage to the semiconductor switches and reduced efficiency due to heat generation.

[0007] However, if multiple inverters are connected in parallel and the multiple cooling fans arranged in each inverter are operated even when the vehicle is powered by a battery, a problem occurs in that a large amount of power is consumed from the battery, resulting in a shortage of power to drive the motor. To solve this problem, an emergency battery should have a capacity to drive all the cooling fans in addition to a capacity to drive the motor for rescue operation.

[0008] However, increasing the capacity of the emergency battery results in an increased cost for the elevator as a whole, and so it is not desirable to provide an emergency battery with too large a capacity.

[0009] An object of the present invention is to provide an inverter device and an inverter cooling method that can reduce the capacity of an emergency battery when inverters connected in parallel are provided. [Means for solving the problem]

[0010] In order to solve the above problems, for example, the configurations described in the claims are adopted. The present application includes a number of means for solving the above problems. One example of such a means is an inverter device having N inverter units (N is an integer of 2 or more) connected in parallel, the inverter device including M cooling fans (M is an integer of 2 or more) arranged in each of the N inverter units, a first power supply circuit that supplies drive power to a first group of cooling fans among the M cooling fans arranged in each inverter unit, a second power supply circuit that supplies drive power to a second group of cooling fans among the M cooling fans arranged in each inverter unit, and a power supply circuit that supplies power to the second power supply circuit during a power outage. and does not supply power to the first power supply circuit during a power outage. Equipped with a battery for power outages and During a power outage, the second group of cooling fans is operated by power from the power outage battery, and the first group of cooling fans is not operated. Effect of the Invention

[0011] According to the present invention, in the event of a power outage, among a plurality of cooling fans, only some of the cooling fans are supplied with power from a battery for use in the event of a power outage, and the power supply capacity required to operate the cooling fans is reduced, allowing the battery capacity to be made smaller. Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram showing a schematic configuration of an inverter device circuit and an elevator according to an embodiment of the present invention; [Diagram 2] 2 is a plan view showing an example of the arrangement of the inverter device shown in FIG. 1. [Diagram 3] 1 is a perspective view showing the shape of one unit of an inverter device according to an embodiment of the present invention; [Figure 4] 1 is a diagram showing a power supply configuration for a cooling fan of an inverter device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An inverter control system according to one embodiment of the present invention (hereinafter referred to as "this embodiment") will be described below with reference to the accompanying drawings. The inverter control system of this embodiment is a system for an inverter device that supplies power to a hoist of an elevator, which is a lifting machine.

[0014] [Inverter device configuration] Fig. 1 shows a circuit configuration of the inverter device 100. Fig. 1 also shows a schematic configuration of an elevator to which power is supplied by the inverter device 100. The inverter device 100 includes a first parallel inverter 110, a second parallel inverter 120, . . . , an Nth parallel inverter 190 (N is an integer of 2 or more).

[0015] Two inverter units are connected in series to each of the parallel inverters 110 to 190. For example, the first parallel inverter 110 has two inverter units 111 and 112 connected in parallel. The inverter unit 111 operates as a converter that converts the three-phase AC power supply 11 into DC, and has six semiconductor switches in total, two for each of the U phase, V phase, and W phase, namely, 111-U1, 111-U2, 111-V1, 111-V2, 111-W1, and 111-W2. In addition, the inverter unit 111 is connected to a capacitor 111-C that smoothes the power supply after it has been converted into a direct current. A power supply filter unit 12 is connected between the three-phase AC power supply 11 and the inverter unit 111 .

[0016] The inverter unit 112 converts the DC obtained by the inverter unit 111 into a three-phase AC power supply, and has six semiconductor switches in total, 112-U1, 112-U2, 112-V1, 112-V2, 112-W1, and 112-W2, two for each of the U phase, V phase, and W phase. A capacitor 112-C is also connected to the DC side of the inverter unit 112.

[0017] Similarly, the second parallel inverter 120 to the Nth parallel inverter 190 each include two inverter units 121, 122 to 191, and 192. For example, the inverter unit 121 of the second parallel inverter 120 includes six semiconductor switches 121-U1, 121-U2, 121-V1, 121-V2, 121-W1, and 121-W2, and performs an operation of converting a three-phase AC power supply into a DC power supply. Also, the inverter unit 122 of the second parallel inverter 120 includes six semiconductor switches 122-U1, 122-U2, 122-V1, 122-V2, 122-W1, and 122-W2, and performs an operation of converting a DC power supply into a three-phase AC power supply.

[0018] Furthermore, the inverter unit 191 of the Nth parallel inverter 190 has six semiconductor switches 191-U1, 191-U2, 191-V1, 191-V2, 191-W1, and 191-W2, and operates to convert three-phase AC power to DC power. Also, the inverter unit 192 has six semiconductor switches 192-U1, 192-U2, 192-V1, 192-V2, 192-W1, and 192-W2, and operates to convert DC power to three-phase AC power.

[0019] For each of the two inverter units 121, 122 to 191, 192 of the second parallel inverter 120 to the N-th parallel inverter 190, capacitors 121-C, 122-C to 191-C, 192-C are connected.

[0020] The semiconductor switches (121-U1, etc.) arranged in the respective inverter units 111, 112 to 191, 192 are composed of semiconductor elements such as IGBTs, and are on / off controlled by the inverter control unit. In this case, the voltage and frequency for driving the elevator are set by on / off control of the inverter units 112 to 192 which obtain the three-phase AC power supply of each of the parallel inverters 110 to 190.

[0021] The three-phase AC power obtained by the inverter units 112 to 192 of each of the parallel inverters 110 to 190 is supplied via a reactor 13 to a motor (for example, a three-phase synchronous motor) 14 serving as a hoist for the elevator.

[0022] To briefly explain the elevator configuration, a main rope 16 is wound around a net wheel 15 that rotates in conjunction with the rotation of a motor 14. A car 17 is connected to one end of the main rope 16, and a counterweight 19 is connected to the other end, so that the car 17 rises and falls as the motor 14 rotates. A load sensor 18 is installed on the car 17 as a load detection unit that detects the load on the car 17. The inverter device 100 is installed, for example, in a machine room of an elevator.

[0023] [Example of inverter device placement] FIG. 2 shows an example of the arrangement of the inverter device 100 of this embodiment. The inverter device 100 in the example of FIG. 2 has a four-parallel configuration including a first parallel inverter 110 to a fourth parallel inverter 140. In the example of FIG. Each of the parallel inverters 110-140 includes two inverter units, so that there are eight inverter units 111-141 and 112-142 in total.

[0024] Here, as shown in Fig. 2, the inverter device 100 of this example has eight inverter units 111-141 and 112-142 stacked vertically on the control panel 109. That is, in the example of Fig. 2, the inverter units are arranged in the following order from the top: 111, 121, 131, 141, 112, 122, 132, 142. However, the arrangement of the units shown in Fig. 2 is just an example, and other arrangement orders may also be used.

[0025] Each of the inverter units 111, 112, 121, 122, 131, 132, 141, and 142 includes six semiconductor switches (not shown in FIG. 2), and each unit is provided with three cooling fans. For example, cooling fans 111-F1, 111-F2, and 111-F3 are attached to the inverter unit 111. Similarly, cooling fans indicated by adding "F1, F2, and F3" to the end of the reference numerals of the inverter units 121 to 141 and 112 to 142 are attached to the inverter units 121 to 141 and 112 to 142. Handles 101 are attached to the left and right ends of each of the inverter units 111 to 142.

[0026] The four inverter units 111, 121, 131, and 141 operating as converters are connected in parallel to the three terminals 102U, 102V, and 102W of the terminal section 102. The three terminals 102U, 102V, and 102W of the terminal section 102 are connected to the three-phase AC power supply 11 side shown in FIG.

[0027] Further, the four inverter units 112, 122, 132, and 142 operating as inverters are connected in parallel to the three terminals 103U, 103V, and 103W of the terminal section 103. The three terminals 103U, 103V, and 103W of the terminal section 103 are connected to the motor 14 side shown in FIG. The parallel inverters 110 to 140 are set to have the same maximum output current.

[0028] [Inverter unit configuration] FIG. 3 is a perspective view showing the configuration of one inverter unit 111. As shown in FIG. The other inverter units 112 to 142 have the same configuration as the inverter unit 111. The inverter unit 111 has three cooling fans 111-F1, 111-F2, and 111-F3 attached to the front side of the frame 107, which also serves as a heat sink. The inverter unit 111 has six semiconductor switches 111-U1, 111-U2, 111-V1, 111-V2, 111-W1, and 111-W2. In this example, the inverter unit is configured using a 2-in-1 type IGBT module, but a 1-in-1 or 6-in-1 type may also be used. The inverter unit 111 also includes a capacitor 111-C and other components. Handles 101 are attached to the left and right ends of the front side of the frame 107.

[0029] Three-phase AC side terminals 104-U, 104-V, and 104-W are arranged on the front side of the upper part of frame 107, and DC side terminals 105-P and 105-N are arranged on the rear side of the upper part of frame 107. In the case of the inverter unit 111 operating as a converter, the terminals 104-U, 104-V, and 104-W on the three-phase AC side are connected to the three-phase AC power source 11 (FIG. 1). In the case of the inverter unit 121 operating as an inverter, the terminals 104-U, 104-V, and 104-W on the three-phase AC side are connected to the motor 14 side. The DC side terminals 105-P, 105-N are connected to DC side terminals (not shown) of the inverter units 112 of the same parallel inverter 110.

[0030] [Cooling fan power supply configuration] FIG. 4 shows a power supply configuration for cooling fans 111-F1, 111-F2, . . . , 142-F3 arranged in the inverter device 100 of this embodiment. The inverter device 100 in the example of Figure 4 is configured in four parallel configurations, the first parallel inverter 110 to the fourth parallel inverter 140, as in Figure 2, and eight inverter units 111, 121, ..., 142 are stacked and arranged within the control panel 109 (Figure 2).

[0031] As already described, three cooling fans are attached to each of the inverter units 111, 121, . . . , 142. For example, the inverter unit 111 is attached with cooling fans 111-F1, 111-F2, and 111-F3. Here, a first power supply circuit 22 and a second power supply circuit 23 are prepared as power supply circuits for supplying power to operate the cooling fans 111-F1 to 142-F3.

[0032] The first power supply circuit 22 and the second power supply circuit 23 are supplied with commercial AC power from the building power supply 21. The first power supply circuit 22 and the second power supply circuit 23 obtain a relatively low-voltage power supply for operating a motor (not shown) built into each of the cooling fans 111-F1 to 142-F3. For example, if the motor built into each of the cooling fans 111-F1 to 142-F3 is a DC motor, the first power supply circuit 22 and the second power supply circuit 23 perform a power supply process for converting the commercial AC power supply into a low-voltage DC power supply. Even if the motor is an AC motor, the first power supply circuit 22 and the second power supply circuit 23 perform voltage conversion and the like as necessary.

[0033] A power failure battery 24 is connected to the second power supply circuit 23. This power failure battery 24 has a capacity capable of supplying power to a corresponding cooling fan during rescue operation at least during a power failure of the elevator to which power is supplied by the inverter device 100 of this embodiment. Therefore, during a power outage, only the cooling fans powered by the second power supply circuit 23 operate, and the cooling fans powered by the first power supply circuit 22 do not operate.

[0034] The power from the first power supply circuit 22 is supplied to two of the three cooling fans in each of the inverter units 111, 121, ..., 142 (first power supply process). And the power from the second power supply circuit 23 is supplied to the remaining one of the three cooling fans in each of the inverter units 111, 121, ..., 142 (second power supply process).

[0035] 4 will be described from the top down. In the inverter unit 111, power is supplied to the cooling fans 111-F2 and 111-F3 from the first power supply circuit 22. Power is supplied to the cooling fan 111-F1 from the second power supply circuit 23. In the inverter unit 121, power is supplied to the cooling fans 121-F1 and 121-F3 from the first power supply circuit 22. Moreover, power is supplied to the cooling fan 121-F2 from the second power supply circuit .

[0036] In the inverter unit 131, power is supplied to the cooling fans 131-F1 and 131-F2 from the first power supply circuit 22. Moreover, power is supplied to the cooling fan 131-F3 from the second power supply circuit . In the inverter unit 141, power is supplied to the cooling fans 141-F1 and 141-F3 from the first power supply circuit 22. Moreover, power is supplied to the cooling fan 141-F2 from the second power supply circuit .

[0037] In the inverter unit 112, power is supplied to the cooling fans 112-F2 and 112-F3 from the first power supply circuit 22. Moreover, power is supplied to the cooling fan 112-F1 from the second power supply circuit . In the inverter unit 122, power is supplied to the cooling fans 122-F1 and 122-F3 from the first power supply circuit 22. Moreover, power is supplied to the cooling fan 122-F2 from the second power supply circuit . In the inverter unit 132, power is supplied to the cooling fans 132-F1 and 132-F2 from the first power supply circuit 22. Moreover, power is supplied to the cooling fan 132-F3 from the second power supply circuit .

[0038] In the inverter unit 142, power is supplied to the cooling fans 142-F1 and 142-F3 from the first power supply circuit 22. Moreover, power is supplied to the cooling fan 142-F2 from the second power supply circuit . 4 indicates a cooling fan that is operated by power from the second power supply circuit 23. The cooling fan that is surrounded by a dashed line in Fig. 4 operates even during a power outage.

[0039] [Effects of the inverter device in this example] In this example, the cooling fan that operates during a power outage is one of the three cooling fans arranged in one inverter unit. Therefore, each inverter unit 111 to 142 performs a minimum cooling operation, and can appropriately perform rescue operation during a power outage. That is, in rescue operation during a power outage, the elevator operates at a low speed to the nearest floor. At this time, the current of the power source supplied to the motor 14 is relatively small and the operation time is short, so the necessary cooling performance can be appropriately maintained even in a situation where only a few cooling fans are operating.

[0040] In this example, the cooling fans that operate during a power outage are shifted horizontally by one for each inverter unit, as shown in Fig. 4. That is, the cooling fans that operate during a power outage are shifted one by one in the order of the left end of the top inverter unit 111, the center of the second inverter unit 121, the right end of the third inverter unit 131, the center of the fourth inverter unit 141, ...

[0041] Therefore, as a cooling operation during a power outage, the cooling air from each cooling fan passes almost evenly through the inverter device 100. Therefore, although the cooling performance is inferior to normal times due to the fewer cooling fans in operation, the entire inverter device 100 can be kept in a state where it can be cooled efficiently, so that the power supply from the inverter device 100 for rescue operation during a power outage can be efficiently converted.

[0042] [Variations] It should be noted that the embodiment examples described so far have been described in detail in order to explain the present invention in an easily understandable manner, and are not necessarily limited to those having all of the configurations described. For example, in the power supply configuration shown in Fig. 4, the cooling fans to which power is supplied from the battery 24 during a power outage are arranged in a staggered manner so that they are shifted in sequence one step at a time. In contrast, the cooling fans to which power is supplied from the battery 24 during a power outage may be set in an arrangement different from that shown in Fig. 4. Moreover, the arrangement of the inverter units 111 to 142 shown in FIG. 2 and FIG. 4 is also an example, and other configurations may be used.

[0043] In the above-described embodiment, the inverter device is applied to supply power to the motor of an elevator, but the inverter device may be applied to a motor of a lift other than an elevator. For example, the inverter device may be applied to supply power to a motor of a lift such as an escalator. The same effect can be obtained when the inverter device is applied to a motor other than an elevator that performs emergency operation in the event of a power outage. [Explanation of symbols]

[0044] 11...three-phase AC power supply, 12...power supply filter section, 13...reactor, 14...motor, 15...net pulley, 16...main rope, 18...load sensor, 19...balance weight, 21...building power supply, 22...first power supply circuit, 23...second power supply circuit, 24...emergency battery, 100...inverter device, 101...handle, 102, 103...terminal section, 102U, 102V, 102W...terminal, 103...terminal section, 103U...terminal, 104-U, 104-V, 104-W, 105-P, 105-N...terminal, 107...frame, 109...control panel, 110~190...parallel inverter, 111, 112, 121, 122, 131, 132, 141, 142...inverter unit 111-C, 112-U1... Capacitor, 111-F1, 111-F2, 111-F3... Cooling fan, 111-U1, 111-U2, 111-V1, 111-V2, 111-W1, 111-W2... Semiconductor switch

Claims

1. In an inverter device having N inverter units (N is an integer of 2 or more) connected in parallel, M cooling fans (M is an integer of 2 or more) are arranged in each of the N inverter units; a first power supply circuit that supplies driving power to a first group of the cooling fans among the M cooling fans arranged for each inverter unit; a second power supply circuit that supplies driving power to a second group of the cooling fans among the M cooling fans arranged for each inverter unit; a power failure battery that supplies power to the second power supply circuit during a power failure and does not supply power to the first power supply circuit during a power failure; During the power outage, the second group of cooling fans is operated by the power source from the power outage battery, and the first group of cooling fans is not operated. Inverter device.

2. the second group of cooling fans is one for each of the inverter units; The first group of cooling fans is (M-1) for each inverter unit. The inverter device according to claim 1 .

3. The N inverter units are housed in a control panel arranged in a stack, The cooling fans that are shifted vertically in order while being housed in the control panel are selected as the second group of cooling fans. The inverter device according to claim 2 .

4. The inverter units connected in parallel supply power to a motor of an elevator, The power failure battery is a battery having a capacity required to operate the cooling fan when the elevator is operated for rescue in the event of a power failure. The inverter device according to any one of claims 1 to 3.

5. 1. An inverter cooling method for cooling N inverter units (N is an integer of 2 or more) connected in parallel with a cooling fan, comprising the steps of: M cooling fans (M is an integer of 2 or more) are arranged in each of the N inverter units, a first power supply process for supplying driving power to a first group of the cooling fans among the M cooling fans arranged for each inverter unit, and not supplying power from a battery to the first group of the cooling fans during a power outage; a second power supply process for supplying driving power to a second group of the cooling fans among the M cooling fans arranged for each inverter unit, and for supplying power from the battery to the second group of cooling fans during a power outage. Inverter cooling method.

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