Electric vehicle driving system

Abstract

An electric vehicle drive system (200) is provided with: a control device (120) for controlling motors (80, 81) for driving axles (40a, 40b) of a trolley (40) for driving an electric vehicle (150A); and a control device (121) for controlling motors (82, 83) for driving axles (41a, 41b) of a trolley (41). The control device (120, 121) includes an inverter (60) and a control unit (30) that controls the inverter (60). The control device (120) is housed in the housing (260), and the control device (121) is housed in the housing (261). Coolers (270, 271) for cooling by the traveling wind are respectively attached to the housing (260, 261). The control devices (120, 121) are distributed in the vicinity of the trolley (40) and the vicinity of the trolley (41).

Description

Technical Field

[0001] This disclosure relates to a tram drive system including a plurality of tram control devices for controlling the electric motors that drive the tram. Background Technology

[0002] The tram control unit (hereinafter, appropriately referred to as the "control unit") operates by receiving power from overhead lines, and is therefore mostly mounted on the roof or under the floor of the tram. The control unit has an inverter with built-in semiconductor elements. The inverter is electrically connected to the electric motor used for running the tram. Direct current (DC) is supplied to the inverter. The semiconductor elements of the inverter perform switching operations, converting the DC power into the desired alternating current (AC) power and supplying it to the electric motor. The electric motor is driven by the converted AC power. The semiconductor elements of the inverter generate heat during the switching operations. Therefore, a cooler is installed on the frame housing the inverter.

[0003] Patent Document 1 disclosed a cooling system that utilizes the airflow from a moving tram to cool an inverter, wherein two cooling systems are connected in series and arranged close to each other along the tram's direction of travel.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 6494408 Utility Model Content

[0007] Technical problem to be solved by the utility model

[0008] However, in the structure of Patent Document 1, it is difficult to efficiently cool multiple inverters. For example, when the area of ​​the cooler is divided into windward and leeward sections relative to the driving wind, the inverter cooled by the cooler located on the windward side is easily cooled by the efficient intake of the driving wind. In contrast, for the inverter cooled by the cooler located on the leeward side, since the two coolers are close together, the driving wind is not easily drawn into the cooler on the leeward side and is affected by the heat generated by the inverter located on the windward side, causing the temperature of the driving wind to tend to rise, and the cooling conditions become more stringent.

[0009] Therefore, in order to achieve adequate cooling even on the leeward side, it is sometimes necessary to use a high-performance cooler that also incorporates heat pipes or a large cooler. Furthermore, Patent Document 1 employs a structure in which an air guide for directing airflow is provided on the cooler on the leeward side. However, in the prior art, there are technical problems arising from the increasing size and manufacturing cost of the control device.

[0010] Furthermore, when the control unit is mounted under the tram floor, the limited space under the floor sometimes means there isn't enough room to house the control unit's frame. In such cases, it's necessary to miniaturize the components and reduce the size of the frame by changing the specifications of the control unit. Additionally, re-evaluating the specifications sometimes results in a reduction in the tram's functionality or performance compared to the original design.

[0011] This invention is proposed in view of the above circumstances, and its purpose is to provide a tram drive system that can flexibly configure the control device within the limited space of the tram to achieve efficient cooling.

[0012] Technical solutions to solve technical problems

[0013] To solve the aforementioned technical problems and achieve the objectives, the tram drive system disclosed herein includes multiple control devices that control at least one of the four motors on the four axles of the two trams driving the tram. Each control device has an inverter that supplies power to at least one motor and a control unit that controls the inverter. The inverter and the control unit are housed together in a housing, and at least one control device is housed in each housing. A cooler that utilizes the airflow generated by the tram's movement to cool the inverter is installed in each housing. The multiple control devices are distributed near the first tram located in front of the tram in the direction of travel and near the second tram located behind the tram in the direction of travel.

[0014] Utility Model Effect

[0015] According to the tram drive system disclosed herein, it has the effect of flexibly configuring the control device within the limited space of the tram to achieve effective cooling. Attached Figure Description

[0016] Figure 1 This is a diagram illustrating a structural example of the tram drive system according to Embodiment 1.

[0017] Figure 2 This is a diagram showing an existing mounting example as a comparative example.

[0018] Figure 3 This is the first figure used to illustrate a first mounting example of the electric vehicle drive system according to Embodiment 1.

[0019] Figure 4 This is the second figure used to illustrate a first mounting example of the electric vehicle drive system according to Embodiment 1.

[0020] Figure 5 This is a diagram illustrating a second mounting example of the tram drive system according to Embodiment 1.

[0021] Figure 6 This is a diagram illustrating a third mounting example of the electric vehicle drive system according to Embodiment 1.

[0022] Figure 7 This is a diagram illustrating a fourth mounting example of the tram drive system according to Embodiment 1.

[0023] Figure 8 This is a graph showing the results of the first verification test used to illustrate the effect of obstacles on the airflow to the cooler.

[0024] Figure 9 This is a graph showing the results of a second verification test used to illustrate the effect of obstacles on the airflow to the cooler.

[0025] Figure 10 This is a diagram illustrating an example of the installation of the tram drive system according to Embodiment 2. Detailed Implementation

[0026] The tram drive system according to the embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. In addition, for ease of understanding, the scale of each component in the drawings may sometimes differ from the actual scale. The same applies between the individual drawings. Furthermore, hereinafter, physical connections and electrical connections will not be distinguished; the term "connection" will be used only. That is, the term "connection" includes both cases where the constituent elements are directly connected to each other and cases where the constituent elements are indirectly connected to each other via other constituent elements.

[0027] Implementation method 1.

[0028] Figure 1 This is a diagram illustrating a structural example of the tram drive system according to Embodiment 1. In Figure 1 The diagram shows an example of the structure of a tram.

[0029] like Figure 1 As shown, the tram drive system 200 includes four control devices 100-103 that receive DC power from the overhead line 1 via the current collector 2. A substation (not shown) is located upstream of the overhead line 1, and the overhead line 1 is the location of the external power source as viewed from the control devices 100-103. The voltage applied to the overhead line 1 by the current collector 2 (i.e., the overhead line voltage) and the conversion capacities of the control devices 100-103 vary depending on the drive method of the tram drive system. The overhead line voltage ranges approximately from 600 to 3000 V. Furthermore, the conversion capacities range from tens to hundreds of kVA.

[0030] Four electric motors 80-83, used to drive the tram, are connected to control units 100-103. Direct current (DC) supplied from overhead line 1 and current collector 2 is provided to control units 100-103 via switch 10, reactor 11, and wire 20. Each positive terminal P of control units 100-103 is connected to reactor 11. Furthermore, each negative terminal N of control units 100-103 is connected to track 4 via wheels 3. Thus, the DC current generated by the DC power supplied from overhead line 1 flows through switch 10, reactor 11, wire 20, control units 100-103, electric motors 80-83, wheels 3, and track 4, returning to the substation. Figure 1 In the structure, the reactor 11, the wire 20, and the control devices 100-103 constitute the components of the tram drive system 200. The wire 20 includes conductors such as copper or aluminum. An example of a conductor is a busbar.

[0031] In addition, Figure 1 In the diagram, an overhead power line is shown as overhead line 1, and pantograph-shaped current collectors are shown as current collectors 2, but the design is not limited to these. The overhead line 1 could also be a third track used in subways, etc., and correspondingly, the current collector 2 could be a current collector for a third track. Furthermore, in... Figure 1 The text indicates that overhead line 1 is a DC overhead line, but overhead line 1 can also be an AC overhead line. Furthermore, when overhead line 1 is an AC overhead line, a transformer is installed between the current collector 2 and the switch 10, or between the switch 10 and the reactor 11, to step down the received AC voltage. A converter is installed after the transformer to convert the AC voltage output from the transformer into a DC voltage.

[0032] The control device 100 includes a capacitor 50 that maintains a DC voltage, a discharge circuit 52 that discharges the voltage of the capacitor 50, and an inverter 60. Inside the control device 100, the capacitor 50 and the discharge circuit 52 are connected between the positive terminal P and the negative terminal N. Thus, on the input side of the inverter 60, the capacitor 50 and the discharge circuit 52 are connected in parallel with the two ends of the inverter 60.

[0033] Capacitor 50 is connected to reactor 11, and together they form an LC filter circuit. This LC filter circuit suppresses surge voltage flowing in from the overhead line 1 side. In addition, the LC filter circuit is connected to inverter 60 to suppress the magnitude of the pulsating component of the current flowing through inverter 60.

[0034] The inverter 60 included in the control devices 100-103 is a power conversion circuit that supplies power to the motors 80-83. The inverter 60 converts the DC voltage of the capacitor 50 into an AC voltage of any frequency with any voltage value and applies it to the motors 80-83.

[0035] like Figure 1 As shown, the inverter 60 has six semiconductor elements 60U, 60V, 60W, 60X, 60Y, and 60Z. The semiconductor elements 60U, 60V, 60W, 60X, 60Y, and 60Z are bridged to form a three-phase bridge circuit. Furthermore, although in Figure 1 The diagram is omitted, but control devices 101 to 103, like control device 100, also have an inverter 60.

[0036] In inverter 60, semiconductor elements 60U, 60V, and 60W are referred to as the positive arms, and semiconductor elements 60X, 60Y, and 60Z are referred to as the negative arms. Furthermore, groups of positive and negative arms connected in series are called branches. Semiconductor elements 60U and 60X form the U-phase branch, semiconductor elements 60V and 60Y form the V-phase branch, and semiconductor elements 60W and 60Z form the W-phase branch. As shown in the figure, semiconductor elements 60U, 60V, 60W, 60X, 60Y, and 60Z are preferably insulated-gate bipolar transistors (IGBTs) with built-in anti-parallel diodes. Alternatively, metal-oxide-semiconductor field-effect transistors (MOSFETs) can be used instead of IGBTs.

[0037] Control devices 100 to 103 each have a control unit 30. The control unit 30 generates PWM signals for pulse width modulation (PWM) control of the semiconductor elements 60U, 60V, 60W, 60X, 60Y, and 60Z of the inverter 60, and assigns them to the inverter 60.

[0038] in addition, Figure 1 The diagram illustrates a control method known as "individual control," in which one of the corresponding control devices 100-103 controls each of the four motors 80-83, but is not limited to this structure. The four motors 80-83 are separately mounted on... Figure 1 The two trolleys are not shown in the diagram, but they can also be configured using a control method called "trolley control," where one control device controls two electric motors mounted on one trolley. In the trolley control configuration, control devices 100 and 101 are integrated, and inverters 60 connected to motor 80 and 81 are controlled by a single control unit 30. Similarly, control devices 102 and 103 are integrated, and inverters 60 connected to motor 82 and 83 are controlled by a single control unit 30.

[0039] Figure 2 This diagram illustrates an existing mounting example as a comparative example. Figure 2 In this diagram, a right-handed system of X, Y, and Z axes, orthogonal to each other, is used. The direction of travel, F, is defined as the +X axis, the horizontal direction orthogonal to F is defined as the Y axis, the vertical upward direction orthogonal to F is defined as the +Z axis, and the vertical downward direction orthogonal to F is defined as the -Z axis. Furthermore, in subsequent diagrams, the same system will be used... Figure 2 The same coordinate system. Additionally, in this article, the Y-axis direction is sometimes referred to as the "first direction".

[0040] In existing electric vehicle drive systems, such as those shown in Patent Document 1, Figure 2 As shown, the frame 250, which houses all the components of the tram drive system, is mounted under the floor of the tram 150. Figure 2 This example illustrates the mounting of the aforementioned trolley control method. Relative to the direction of travel F, two motors (not shown) are mounted on the trolley 40 located at the front and the trolley 41 located at the rear. A control device 251 for controlling the two motors of trolley 40 and a control device 252 for controlling the two motors of trolley 41 are mounted on the frame 250. Furthermore, a cooler 253 for cooling the inverter included in the control device 251 and a cooler 254 for cooling the inverter included in the control device 252 are mounted on the side of the frame 250, protruding along the Y-axis. Additionally, in... Figure 2 Although the devices mounted under the floor other than the frame 250 are not shown in the diagram, they actually house various underfloor devices required for the operation of the tram 150. A single tram 150 is approximately 20 meters long, but to ensure sufficient space for these underfloor devices, the length of the frame 250 in the longitudinal direction is at most less than 2 meters.

[0041] As described above, the existing tram drive system is configured such that two coolers 253 and 254 are connected in series and close together along the travel direction F of the tram 150. In this configuration, as described in the section on "Technical Problems to be Solved by the Utility Model," the inverter cooled by the cooler 253 located on the windward side of the travel wind is easily cooled as the travel wind is efficiently drawn into the cooler 253. Conversely, for the inverter cooled by the cooler 254 located on the leeward side of the travel wind, because the two coolers 253 and 254 are close together, the travel wind is not easily drawn into the cooler 254 on the leeward side, and is affected by the heat generated by the inverter on the windward side. The temperature of the travel wind drawn into the cooler 254 tends to rise, making cooling conditions more demanding. Patent Document 1 employs a structure in which a wind guide for guiding the travel wind is provided on the cooler on the leeward side, but this results in the technical problem of increased control device size and manufacturing costs.

[0042] To address the aforementioned technical problems, in Implementation Method 1, the following is first proposed: Figure 3 and Figure 4 The example shown is an example of how it can be mounted. Figure 3 This is the first figure used to illustrate a first mounting example of the electric vehicle drive system according to Embodiment 1. Figure 4 This is the second figure used to illustrate a first mounting example of the electric vehicle drive system according to Embodiment 1. Figure 3 This diagram is obtained by observing tram 150A from the side in the negative direction of the Y-axis. Figure 4 This is a view taken from the floor of tram 150A, facing the negative direction of the Z-axis, showing the floor below tram 150A. Furthermore, in the following explanations, it will also be related to... Figure 3 and Figure 4 The same diagram is used. Additionally, Figure 3 and Figure 4 The diagram shows an example of a trolley control system, with two control devices per trolley. For ease of explanation, one control device is designated "control device 120" and the other "control device 121".

[0043] exist Figure 3 and Figure 4In this system, the components of the tram drive system 200 are distributed under the floor of the tram 150A. Specifically, the housing 250A for the switch 10 and reactor 11 is located in the center of the floor. The housing 260 for the control device 120 is located away from the center of the floor, near the trolley 40 in the direction of travel F of the tram 150A; specifically, it is located behind and to the left of the trolley 40 relative to the direction of travel F. Similarly, the housing 261 for the control device 121 is located away from the center of the floor, near the trolley 41 behind the tram 150A in the direction of travel F; specifically, it is located in front of and to the right of the trolley 41 relative to the direction of travel F.

[0044] A cooler 270 for cooling the two inverters 60 of the cooling control device 120 is mounted on the frame 260, such that the cooler 270 protrudes from the side of the frame 260 along the +Y axis direction. Additionally, a cooler 271 for cooling the two inverters 60 of the cooling control device 121 is mounted on the frame 261, such that the cooler 271 protrudes from the side of the frame 261 along the -Y axis direction.

[0045] The trolley 40 is equipped with motors 80 and 81, which are respectively connected to the control device 120. Motor 80 drives the front axle 40a of the trolley 40 relative to the direction of travel F, and motor 81 drives the rear axle 40b of the trolley 40 relative to the direction of travel F.

[0046] The trolley 41 is equipped with motors 82 and 83, which are respectively connected to the control device 121. Motor 82 drives the front axle 41a of the trolley 41 relative to the direction of travel F, and motor 83 drives the rear axle 41b of the trolley 41 relative to the direction of travel F. In this document, the trolley 40 is sometimes referred to as "first trolley," and the trolley 41 as "second trolley." Also in this document, the control device 120 is sometimes referred to as "first control device," and the control device 121 as "second control device."

[0047] When a heat-generating object is present near the windward side, the temperature of the driving air drawn into the cooler rises. Conversely, in... Figure 3 and Figure 4 In this structure, since the cooler 270 located on the windward side of the driving wind and the cooler 271 located on the leeward side of the driving wind are arranged with a sufficient distance between them, it can be considered that there are no heat-generating objects in close proximity. Therefore, in Figure 3 and Figure 4 In this structure, the difference in cooling conditions between the cooler 271 located on the leeward side and the cooler 270 located on the windward side can be reduced. Therefore, in Figure 3 and Figure 4In this structure, the large size of the control devices 120 and 121 and the increased manufacturing cost of the control devices 120 and 121 can be avoided.

[0048] In addition, Figure 4 In the diagram, the equipment limit line 280 is shown with a single-dotted line relative to the width of vehicle 5 of tram 150A. The equipment limit line 280 represents the boundary line on the width side of the area for mounting items under the floor. That is, items mounted under the floor cannot be mounted beyond the outer edge of the equipment limit line 280. The equipment limit line 280 is widest relative to the width of vehicle 5 at the positions of trolleys 40 and 41, and narrowest at the center under the floor. Therefore, compared to the prior art structure where the housing 250 of the control device is located in the center under the floor, the structure of Embodiment 1, which places the housings 260 and 261 of the control devices 100-103 near trolleys 40 and 41, can be considered a structure that easily draws in running air. Thus, it can be considered that... Figure 3 and Figure 4 Structure and Figure 2 Compared to the existing technology, this structure improves the cooling performance of coolers 270 and 271. Therefore, if... Figure 3 and Figure 4 The structure allows for the configuration of control devices 120 and 121 in a manner that enables effective cooling.

[0049] In addition, Figure 3 and Figure 4 In this structure, all components of the electric vehicle drive system 200 are not housed in a single frame, but rather in three frames 250A, 260, and 261. Therefore, although the number of frames increases, the smaller size of each individual frame allows for efficient use of the space under the floor.

[0050] Figure 5 This is a diagram illustrating a second mounting example of the tram drive system according to Embodiment 1. Figure 4 In this configuration, the frames 260 of the storage control device 120 and 261 of the storage control device 121 are positioned at opposite poles, that is, rotationally symmetrical when viewed from the center under the floor. In contrast, in... Figure 5 In the middle, the frame 260 of the storage control device 120 remains unchanged, and the frame 261 of the storage control device 121 is arranged in the same column as the frame 260, that is, along the direction of travel F, the frame 260 and the frame 261 are arranged in series.

[0051] like Figure 5 As shown, even when the cooler 270 on the windward side and the cooler 271 on the leeward side are arranged in the same row, the spacing between the cooler 270 on the windward side and the cooler 271 on the leeward side is also the same as... Figure 4 The situation is almost the same. That is, since the cooler 270 on the windward side and the cooler 271 on the leeward side are configured with a sufficient gap between them, it can also be said that there are no heat-generating objects in close proximity. Therefore, even Figure 5 The example of its integration also allows us to obtain... Figure 4 The same effect is achieved with the example of its mounting.

[0052] Next, an example of a separate control method will be explained. Figure 6 This diagram illustrates a third mounting example of the tram drive system according to Embodiment 1. In the case of individual control, the components of the tram drive system 200 are also distributed under the floor of the tram 150A. Specifically, the housing 250A for housing the switch 10 and the reactor 11 is located in the center under the floor. Furthermore, the housing 262 for housing the control device 100 is located near the trolley 40 in front of the tram 150A in the direction of travel F; specifically, it is located in front of and to the right of the trolley 40 relative to the direction of travel F. Additionally, the housing 263 for housing the control device 101 is located near the trolley 40 in front of the tram 150A in the direction of travel F; specifically, it is located behind and to the left of the trolley 40 relative to the direction of travel F. Similarly, the housing 264 of the storage control device 102 is positioned near the trolley 41 located behind the tram 150A in the direction of travel F, specifically, in front of and to the right of the trolley 41 relative to the direction of travel F. Furthermore, the housing 265 of the storage control device 103 is positioned near the trolley 41 located behind the tram 150A in the direction of travel F, specifically, in front of and to the left of the trolley 41 relative to the direction of travel F. Additionally, in this document, the two control devices 100 and 101 that individually control the two motors 80 and 81 mounted on the trolley 40 (which is the first trolley) are sometimes referred to as "first control devices." Furthermore, the two control devices 102 and 103 that individually control the two motors 82 and 83 mounted on the trolley 41 (which is the second trolley) are sometimes referred to as "second control devices."

[0053] A cooler 272 for cooling the inverter 60 included in the cooling control device 100 is mounted on the frame 262, such that the cooler 272 protrudes along the -Y-axis direction from the side of the frame 262. Similarly, a cooler 273 for cooling the inverter 60 included in the cooling control device 101 is mounted on the frame 263, such that the cooler 273 protrudes along the +Y-axis direction from the side of the frame 263. Furthermore, a cooler 274 for cooling the inverter 60 included in the cooling control device 102 is mounted on the frame 264, such that the cooler 274 protrudes along the -Y-axis direction from the side of the frame 264. Finally, a cooler 275 for cooling the inverter 60 included in the cooling control device 103 is mounted on the frame 265, such that the cooler 275 protrudes along the +Y-axis direction from the side of the frame 265.

[0054] exist Figure 6 In the structure of the trolley 40, the cooler 272 located on the windward side of the traveling wind and the cooler 273 located on the leeward side of the traveling wind are arranged with a distance between them that is at least equivalent to the length of the trolley 40, so it can be said that there are no heat-generating objects in close proximity. Therefore, in Figure 6 In this structure, the difference in cooling conditions between the cooler 272 located on the windward side and the cooler 273 located on the leeward side can be reduced. This relationship also applies to the coolers 274 and 275 in the trolley 41. Therefore, in Figure 6 In this structure, the situation of increasing the size of the control device 100-103 and the increase in the manufacturing cost of the control device 100-103 can be avoided.

[0055] In addition, Figure 6 In the structure, the frames 262-265 that house the control devices 100-103 can be positioned near the wider trolleys 40 and 41 between the equipment limit lines 280. Therefore, if for Figure 6 With this structure, even a structure with a single control mode can be configured with control devices 100 to 103 in a way that achieves effective cooling.

[0056] In addition, Figure 6 In this structure, all components of the tram drive system 200 are not housed in a single frame, but rather distributed across five frames 250A, 262-265. Thus, although the number of frames increases, the smaller size of each individual frame allows for efficient use of the space under the floor.

[0057] Figure 7 This is a diagram illustrating a fourth mounting example of the tram drive system according to Embodiment 1. Figure 6In this configuration, for each trolley 40, 41, the frames 262, 263 of the storage control devices 100, 101 are positioned at opposite poles, i.e., diagonal positions within trolley 40; and the frames 264, 265 of the storage control devices 102, 103 are positioned at opposite poles, i.e., diagonal positions within trolley 41. Furthermore, when viewed from the center under the floor, the frames 263 of the storage control device 101 and 264 of the storage control device 102 are positioned at opposite poles. Conversely, in... Figure 7 In this process, for each trolley 40, 41, the relationship between the frames that house each control device and their opposite positions remains unchanged. The frames 263 that house the control device 101 and the frames 264 that house the control device 102 are arranged in the same column in the direction of travel F.

[0058] like Figure 7 As shown, even when the cooler 273 on the windward side and the cooler 274 on the leeward side are arranged in the same row, the spacing between the cooler 273 on the windward side and the cooler 274 on the leeward side is also the same as... Figure 6 The situation is almost the same. That is, since the cooler 273 on the windward side and the cooler 274 on the leeward side are configured with a sufficient gap between them, it can be assumed that there are no heat-generating objects in close proximity. Therefore, even Figure 7 The example of its integration also allows us to obtain... Figure 6 The same effect is achieved with the example of its mounting.

[0059] Alternatively, in the case of a standalone control method, it can also be considered Figure 6 and Figure 7 Other than the example of mounting, as long as the four control devices 100 to 103 are distributed near the trolley 40 located in front of the trolley 150A in the direction of travel F and near the trolley 41 located behind the trolley 150A in the direction of travel F, it can be any structure.

[0060] Next, refer to Figure 8 and Figure 9 Explain the impact of obstacles on the airflow towards the cooler. Figure 8 This is a graph showing the results of the first verification test used to illustrate the effect of obstacles on the airflow towards the cooler. Additionally, Figure 9 This is a graph showing the results of a second verification test used to illustrate the effect of obstacles on the airflow to the cooler.

[0061] First, the first verification experiment will be explained. Figure 8 The lower part schematically illustrates the test environment for the first verification test. Figure 8 In the middle, an obstacle 170 is arranged on the windward side of the cooling air, and an aluminum cooler 160 is arranged on the leeward side of the cooling air. Figure 8This is a top view; the length of the obstacle 170 in the height direction is equal to the length of the aluminum cooler 160 in the height direction. Cooling air is supplied by a blower (not shown). The position of the edge 162 of the aluminum cooler 160 is limited by a position limiting part 180. The edge 162 is the portion located on the front end side of the aluminum cooler 160 along the direction of the cooling airflow. Figure 8 In this process, the position of the edge 162 along the direction of the cooling airflow is restricted to coincide with the position of the edge 172 of the obstacle 170 along the direction of the cooling airflow. Furthermore, the width of the aluminum cooler 160, i.e., the length of the aluminum cooler 160 in the direction orthogonal to the cooling airflow, is defined as d. At this time, the position from the position restriction part 180 to d / 2 on the air-blown surface of the aluminum cooler 160 is designated as the "front wind speed measurement point," and the position from the edge 162 of the aluminum cooler 160 to d / 2 is designated as the "side wind speed measurement point." Then, using the shortest distance between the obstacle 170 and the aluminum cooler 160, i.e., the "distance," as a parameter, the wind speed is measured at the front wind speed measurement point and the side wind speed measurement point.

[0062] exist Figure 8 The upper part of the document displays the test results of the first verification test in tabular form. Based on these test results, the following points were clarified.

[0063] (1) In order to obtain the same wind speed as when there is no obstacle 170, the distance between the aluminum cooler 160 and the obstacle 170 needs to be 4.5 meters.

[0064] (2) When the distance between the aluminum cooler 160 and the obstacle 170 is 1.5m, the wind speed in front is about 80% of that when there is no obstacle 170 (=2.2 / 2.8×100).

[0065] Next, the second verification test will be described. In the second verification test, as follows... Figure 9 As shown, the distance between the aluminum cooler 160 and the obstacle 170 is set to 1.5m, so that the position of the wind speed measuring point in front is consistent with the edge 172 of the obstacle 170. That is, with Figure 8 compared to, Figure 9 The aluminum cooler 160 is restricted to protruding d / 2 in a direction orthogonal to the direction of the cooling airflow. In this state, the wind speed at the forward wind speed measuring point is measured both with and without the obstruction 170.

[0066] Although the test results are not shown, Figure 9When the test was conducted under the experimental environment, the wind speed at the front wind speed measurement point remained unchanged regardless of whether there was an obstacle 170 or not. That is, according to the second verification test, the wind speed at the front wind speed measurement point was equal regardless of whether there was an obstacle 170 or not.

[0067] As mentioned above, in Figure 2 In the existing structure shown, the length of the vehicle's longitudinal direction of the frame 250, which houses two coolers 253 and 254, is at most less than 2m. Therefore, the distance between the two coolers 253 and 254 is considered to be approximately 1.5m or less. Thus, the prior art's idea that the cooling performance of the cooler 254, located on the leeward side of the driving wind, is affected by the cooler 253, located on the windward side of the driving wind, is consistent with the results of the aforementioned verification test.

[0068] On the other hand, looking at the structure of this application, firstly, in the trolley control method, the cooler 270 located on the windward side and the cooler 271 located on the leeward side are arranged with a sufficient distance between them. Moreover, the coolers 270 and 271 are arranged near the wider trolleys 40 and 41 between the equipment limit line 280, so they can be arranged in a position that is almost unaffected by obstacles.

[0069] Furthermore, in individual control configurations, for each trolley 40, 41, the coolers 272, 274 on the windward side and the coolers 273, 275 on the leeward side are configured with sufficient separation distance. Moreover, the coolers 272 to 275 are positioned near the wider trolley 40 or trolley 41 between the equipment limit line 280, thus allowing them to be configured in a position almost unaffected by obstacles.

[0070] As described above, the tram drive system according to Embodiment 1 includes multiple control devices that control at least one of the four motors on the four axles of the two trams driving the tram. Each control device has an inverter that supplies power to at least one motor and a control unit that controls the inverter. The inverter and the control unit are housed together in a housing, each housing houses at least one control device, and each housing is equipped with a cooler that uses the running air from the tram's movement to cool the inverter. Furthermore, the multiple control devices are distributed near the first tram in front of the tram in the direction of travel and near the second tram behind it in the direction of travel. According to this configuration of the tram drive system, the cooler on the leeward side can be configured with sufficient spacing relative to the cooler on the windward side. In addition, in the tram drive system according to Embodiment 1, the cooler on the leeward side and the cooler on the windward side are configured near the first and second trams, whose width between the equipment limit lines is wider than the central part under the floor, thus allowing them to be configured in a position that is almost unaffected by obstacles. Thus, a tram drive system can be obtained that allows for the flexible configuration of control devices within the limited space of the tram to achieve effective cooling.

[0071] The above structure is applicable to a tram drive system using a trolley control method, wherein the multiple control devices consist of a first control device that controls two motors mounted on a first trolley and a second control device that controls two motors mounted on a second trolley. In this trolley control method, the frame housing the first control device can be configured such that it is positioned behind the first trolley relative to the direction of travel, and the frame housing the second control device is positioned in front of the second trolley relative to the direction of travel.

[0072] Furthermore, the above structure is applicable to a tram drive system with individual control, wherein the multiple control devices consist of two first control devices that individually control two motors mounted on a first vehicle and two second control devices that individually control two motors mounted on a second vehicle. In this individual control method, the frame housing one of the two first control devices is positioned in front of the first vehicle relative to the direction of travel, the frame housing the other of the two first control devices is positioned behind the first vehicle relative to the direction of travel, the frame housing one of the two second control devices is positioned in front of the second vehicle relative to the direction of travel, and the frame housing the other of the two second control devices is positioned behind the second vehicle relative to the direction of travel. Alternatively, it can be configured such that the frames housing one of the two first control devices and the other two are positioned behind the first vehicle relative to the direction of travel, and the frames housing one of the two second control devices and the other two are positioned in front of the second vehicle relative to the direction of travel.

[0073] Furthermore, in the above structure, the multiple coolers housing the first control device and the second control device can be configured to protrude in a first direction perpendicular to both the direction of travel of the tram and the vertical direction of the tram vehicle and be mounted on the frame.

[0074] Implementation method 2.

[0075] Figure 10 This is a diagram illustrating an example of the installation of the tram drive system according to Embodiment 2. Figure 10 This diagram is obtained by viewing the tram 150B according to Embodiment 2 from the side, looking towards the negative Y-axis. Additionally, Figure 10 This shows an example of a trolley control system. Additionally, regarding... Figure 3 The same or equal constituent elements are marked with the same label.

[0076] Figure 10 The tram 150B involved in Embodiment 2 shown is... Figure 3 The difference between the tram 150A according to Embodiment 1 shown lies in the mounting position and protruding direction of the coolers 270 and 271. Figure 3 In the electric vehicle 150A shown, coolers 270 and 271 are mounted to protrude along the +Y axis or -Y axis direction from the side of the frame 260 or frame 261. In contrast, in Figure 10 In the tram 150B shown, coolers 270 and 271 are mounted to protrude along the -Z axis direction from the underside of frame 260 or frame 261.

[0077] exist Figure 10 In this structure, since the cooler 270 located on the windward side of the driving wind and the cooler 271 located on the leeward side of the driving wind are arranged with a sufficient distance between them, it is possible to obtain a configuration similar to... Figure 3 The same effect as the structure. Additionally, regarding the empty space under the floor, there is less margin in the vehicle's lateral width direction (Y-axis), but more margin in the vehicle's height direction (Z-axis). Figure 10 Structural ratio Figure 3 In cases where the structure is easier to design. Therefore, in Figures 5-7 In the example of its mounting, the structure of Implementation Method 2 can also be adopted.

[0078] The structure shown in the above embodiments is an example that can be combined with other known technologies. The embodiments can be combined with each other, and parts of the structure can be omitted or modified without departing from the spirit of the work.

[0079] Label Explanation

[0080] 1. Overhead line

[0081] 2 Current collector

[0082] 3 wheels

[0083] 4 guide rails

[0084] 5 vehicles

[0085] 10 Switches

[0086] 11 Reactors

[0087] 20 wires

[0088] 30 Control Department

[0089] 40 and 41 vehicles

[0090] 40a, 40b, 41a, 41b axles

[0091] 50 capacitor

[0092] 52 Discharge Circuit

[0093] 60 Inverter

[0094] 60U, 60V, 60W, 60X, 60Y, 60Z semiconductor components

[0095] 80, 81, 82, 83 electric motors

[0096] Control devices 100, 101, 102, 103, 120, 121, 251, 252

[0097] Tram 150, 150A, 150B

[0098] 160 aluminum cooler

[0099] 162, 172 edge

[0100] 170 Obstacles

[0101] 180 Position Restriction Section

[0102] 200 Electric Vehicle Drive System

[0103] Frames 250, 250A, 260, 261, 262, 263, 264, and 265

[0104] Coolers 253, 254, 270, 271, 272, 273, 274, 275

[0105] 280 Equipment Limit Line

[0106] F Direction of travel

[0107] N negative terminal

[0108] P Positive side terminal.

Claims

1. A train drive system having a plurality of control devices that control at least one of four electric motors that drive four axles of two bogies of a train, the train drive system characterized by: each of the control devices including: an inverter that supplies power to at least one of the electric motors; and a control section that controls the inverter, the inverter and the control section being housed in a frame that is disposed in the vicinity of the bogie in a central portion that is wider than a floor under an equipment limit line, at least one of the control devices being housed in each of the frames, a cooler that cools the inverter using running wind caused by running of the train being installed in each of the frames, the plurality of control devices being disposed in the vicinity of a first bogie located in front in a running direction of the train and in the vicinity of a second bogie located in back in the running direction.

2. The train drive system according to claim 1, characterized in that: the plurality of control devices are composed of one first control device that controls two electric motors mounted on the first bogie and one second control device that controls two electric motors mounted on the second bogie.

3. The train drive system according to claim 2, characterized in that: the frame that houses the first control device is disposed in back of the first bogie with respect to the running direction, the frame that houses the second control device is disposed in front of the second bogie with respect to the running direction.

4. The train drive system according to claim 1, characterized in that: the plurality of control devices are composed of two first control devices that individually control two electric motors mounted on the first bogie and two second control devices that individually control two electric motors mounted on the second bogie.

5. The train drive system according to claim 4, characterized in that: the frame that houses one of the two first control devices is disposed in front of the first bogie with respect to the running direction, the frame that houses the other of the two first control devices is disposed in back of the first bogie with respect to the running direction, the frame that houses one of the two second control devices is disposed in front of the second bogie with respect to the running direction, the frame that houses the other of the two second control devices is disposed in back of the second bogie with respect to the running direction.

6. The train drive system according to claim 4, characterized in that: the two frames that house one and the other of the two first control devices are disposed in back of the first bogie with respect to the running direction, the two frames that house one and the other of the two second control devices are disposed in front of the second bogie with respect to the running direction.

7. The train drive system according to any one of claims 2 to 6, characterized in that: the plurality of coolers that house the first control device and the second control device protrude in a first direction that is perpendicular to both the running direction and a vertical direction of a vehicle of the train and are installed in the frames. ​ 8. The electric vehicle drive system according to any one of claims 2 to 6, characterized in that A plurality of the coolers that house the first control device and the second control device protrude vertically downward from the vehicle of the electric vehicle and are installed in the frame body.

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