Load testing system

Abstract

To provide a load testing system capable of reducing power consumption more than before and reducing running costs more than before.SOLUTION: A load testing system 1 for performing an electric load test to a tested motor 10 comprises: the tested motor 10; a first drive circuit 20 for driving the tested motor 10; a power unit 30 that is connected to the first drive circuit 20 and supplies power; a load motor 40 for applying a load to the tested motor 10; a second drive circuit 50 for driving the load motor 40; and a torque measuring instrument 60 for measuring the torque of the tested motor 10. The power unit 30 supplies power generated by the load motor 40 by driving of the tested motor 10 to the power unit 30 as regenerative power via the second drive circuit 50.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a load test system for performing an electrical load test on a test motor.

Background Art

[0002] A spindle for rotatably mounting a cutting blade or a grinding wheel used in machining in a cutting device or a grinding device includes a motor for rotating the spindle (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, in a cutting device, in order to test whether a cutting spindle has an appropriate torque or the like, a load test of the motor of the spindle is performed in advance. Such a load test system for performing a load test of a motor supplies driving power from a driving circuit (driver) that drives the motor to the motor to rotate the spindle at a predetermined rotational speed, and consumes the driving power of the motor with the resistance of a load motor connected to the rotating part of the spindle to perform a torque test or the like.

[0005] However, in such a conventional load test system, since the driving power for driving the motor is consumed as heat by the resistance of the load motor, only useless thermal energy is discharged, and high power consumption and high running costs have been problems.

[0006] The present invention has been made in view of such problems, and an object thereof is to provide a load test system that can reduce power consumption and running costs compared to the conventional ones.

Means for Solving the Problem

[0007] In order to solve the above-described problems and achieve the object, a load test system of the present invention is a load test system that performs an electrical load test on a motor under test, and includes the motor under test, a first drive circuit that drives the motor under test, a power supply device that is connected to the first drive circuit and supplies power, a load motor for applying a load to the motor under test, a second drive circuit that drives the load motor, and a torque measuring device that measures the torque of the motor under test. The power supply device is characterized in that the power generated by the load motor when the motor under test is driven is supplied as regenerative power to the power supply device via the second drive circuit.

[0008] The power supply device has a converter circuit connected to an AC power supply, an inverter circuit that controls the voltage or frequency of the first drive circuit, and a capacitor disposed between the converter circuit and the inverter circuit. The current of the regenerative power may be connected to the capacitor of the power supply device.

[0009] The second drive circuit may convert the AC power generated by the load motor into DC power and supply it to the power supply device.

Advantages of the Invention

[0010] According to the present invention, since the regenerative power generated by the load motor when the motor under test is driven is supplied to the power supply device via the second drive circuit, a part of the drive power for driving the motor under test is recovered as the regenerative power generated by the load motor and reused for the drive power for driving the motor under test. Therefore, the power consumption can be reduced more than before, and the running cost can be reduced more than before.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0012] Embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. Also, the constituent elements described below include those that can be easily assumed by those skilled in the art and substantially identical ones. Furthermore, the configurations described below can be combined as appropriate. Also, various omissions, substitutions, or changes in the configuration can be made without departing from the gist of the present invention.

[0013] 〔Embodiment〕 A load test system 1 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a configuration example of a cutting device 100 in which the load test system 1 according to the embodiment is used. FIG. 2 is an exploded perspective view showing an outline of a main part of the cutting device 100 in which the load test system 1 according to the embodiment is used. First, in this specification, the cutting device 100 in which the load test system 1 according to the embodiment is used will be described. As shown in FIG. 1, the cutting device 100 in which the load test system 1 according to the embodiment is used includes a holding table 110, a cutting unit 120, a moving unit 130, and a control unit 140.

[0014] In an embodiment, the workpiece 200 to be machined by the cutting blade 121 mounted at the tip of the spindle 122 of the cutting device 100 is, for example, a disk-shaped semiconductor device wafer or an optical device wafer made of a base material such as silicon, sapphire, silicon carbide (SiC), gallium arsenide, etc. As shown in FIG. 1, in the workpiece 200, devices 203 are formed in regions partitioned by a plurality of division planned lines 202 formed in a grid pattern on the flat surface 201. In this embodiment, the workpiece 200 has an adhesive tape 205 attached to the back surface 204 on the back side of the surface 201, and an annular frame 206 is attached to the outer edge portion of the adhesive tape 205. However, the present invention is not limited to this. Further, in the present invention, the workpiece 200 may be a rectangular package substrate, a ceramic plate, a glass plate, etc. having a plurality of devices sealed with resin.

[0015] The holding table 110 has a disk-shaped frame body in which a recess is formed, and a disk-shaped suction portion fitted into the recess. The suction portion of the holding table 110 is formed of a porous material such as porous ceramic and is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown). The upper surface of the suction portion of the holding table 110 is a holding surface 111 on which the workpiece 200 is placed and the placed workpiece 200 is suction-held. In this embodiment, the workpiece 200 is placed on the holding surface 111 with the surface 201 facing upward, and the placed workpiece 200 is suction-held from the back surface 204 side through the adhesive tape 205. The upper surface of the holding surface 111 and the frame body of the holding table 110 are arranged on the same plane and are formed parallel to the XY plane, which is a horizontal plane. The holding table 110 is movable in the X-axis direction parallel to the horizontal direction by the X-axis moving unit 131 of the moving unit 130, and is rotatably provided around an axis parallel to the Z-axis direction, which is the vertical direction and perpendicular to the holding surface 111, by a rotation drive source (not shown).

[0016] As shown in FIGS. 1 and 2, the cutting unit 120 includes a cutting blade 121, a spindle 122, a spindle housing 123, a mounting unit 124, and a motor 125. The spindle 122 is rotatably provided about an axis parallel to the Y-axis direction that is parallel to the horizontal direction and orthogonal to the X-axis direction. The spindle 122 is rotated about its axis by a motor 125 connected to the base end portion on the side opposite to the tip end side (the -Y direction shown in FIGS. 1 and 2) of the spindle 122. The spindle 122 is rotatably supported by the spindle housing 123 such that the tip end side of the rotation axis is exposed and the portion excluding the tip end side is accommodated together with the motor 125.

[0017] The motor 125 is provided connected to the base end portion of the spindle 122. When driving power is supplied and it drives to rotate the spindle 122 about its axis, a rotational operation is applied to the tip end side portion 126 of the rotation axis exposed by the spindle housing 123 of the spindle 122. The motor 125 is an example of the motor under test 10 according to the present invention that is the object of the load test of the load test system 1 according to the embodiment. Also, the tip end side portion 126 of the rotation axis exposed by the spindle housing 123 of the spindle 122 rotates when the motor 125, which is an example of the motor under test 10, drives in the load test of the load test system 1 according to the embodiment, and is an example of the rotating portion 11 to which a load is applied by the load motor 40.

[0018] As shown in FIG. 2, the spindle 122 has a screw hole 127 formed at the tip of the rotation axis for screwing with the bolt 190 of the mounting unit 124. The spindle 122 inserts the tip end side portion 126 of the rotation axis through the receiving flange 170 and the nut 180 of the mounting unit 124 into the cutting blade 121, and screws and fastens the bolt 190 to the screw hole 127 through the receiving flange 170, so that the cutting blade 121 is fixed and mounted to the tip end side portion 126 of the rotation axis through the receiving flange 170, the nut 180, and the bolt 190 of the mounting unit 124.

[0019] In the example of the present embodiment shown in FIG. 2, the cutting blade 121 is a hub blade, and includes a circular base 151 formed in an annular shape and having an insertion hole through which the spindle 122 is inserted, and an annular cutting edge 152 protruding from the outer periphery of the circular base 151. The cutting blade 121 is mounted on a portion 126 at the tip side of the rotation axis of the spindle 122 via a mount unit 124, and is rotated around the axis by the spindle 122 serving as the rotation axis, so that the workpiece 200 is cut with the cutting edge 152. Note that the cutting blade 121 is not limited to a hub blade in the present invention, and may be a hubless blade in which the circular base 151 is omitted substantially in the hub blade and the whole is in the shape of an annular cutting edge 152. In this case, in addition to the mount unit 124, the portion 126 at the tip side of the rotation axis of the spindle 122 is fixed and mounted via a pressing flange (not shown).

[0020] The spindle housing 123 exposes the portion 126 at the tip side of the rotation axis of the spindle 122 and houses the portion excluding the portion 126 at the tip side of the rotation axis together with the motor 125, so that the spindle 122 is inserted therethrough. The spindle housing 123 supports the spindle 122 so as to be rotatable around the axis.

[0021] The spindle housing 123 is provided so as to be movable in the Y-axis direction by the Y-axis moving unit 132 of the moving unit 130 and movable in the Z-axis direction by the Z-axis moving unit 133 of the moving unit 130 with respect to the workpiece 200 held on the holding table 110. The spindle 122 rotatably supported by the spindle housing 123 and the cutting blade 121 mounted on the portion 126 at the tip side of the rotation axis of the spindle 122 move together with the spindle housing 123.

[0022] In this embodiment, the mounting unit 124 includes a receiving flange 170, a nut 180, and a bolt 190, as shown in FIG. 2. The receiving flange 170 is formed in a generally axially symmetric shape. As shown in FIG. 2, the receiving flange 170 includes a columnar boss portion 171 that extends in the axial direction, a disc-shaped flange portion 172 that protrudes radially outward from the boss portion 171 on the axial rear end side (the +Y direction side shown in FIG. 2) opposite to the axial front end side (the -Y direction side shown in FIG. 2) of the boss portion 171, and a cylindrical portion 173 that protrudes further on the axial rear end side of the flange portion 172. The receiving flange 170 is integrally formed such that the central axes of the boss portion 171, the flange portion 172, and the cylindrical portion 173 overlap each other. The receiving flange 170 has a mounting hole 174 formed on the inside thereof so as to fit (mate) without a gap with the outer periphery of the tip portion 126 of the rotation axis of the spindle 122 over the boss portion 171, the flange portion 172, and the cylindrical portion 173.

[0023] The receiving flange 170 is mounted on the tip portion 126 of the rotation axis of the spindle 122 by orienting the axial rear end side where the cylindrical portion 173 is formed toward the spindle housing 123 and fitting the mounting hole 174 with the outer periphery of the tip portion 126 of the rotation axis of the spindle 122. When the receiving flange 170 is mounted on the tip portion 126 of the rotation axis of the spindle 122 in this way, the central axis of the receiving flange 170 coincides with the rotation axis of the spindle 122 and is arranged along the Y-axis direction shown in FIG. 2. The cutting blade 121 is mounted on the receiving flange 170 by inserting the boss portion 171 through the insertion hole of the circular base 151 and fitting the insertion hole with the axial rear end side portion of the boss portion 171. When the cutting blade 121 is mounted on the receiving flange 170 in this way, the central axis of the cutting blade 121 coincides with the central axes of the receiving flange 170 and the spindle 122 and is arranged along the Y-axis direction shown in FIG. 2.

[0024] The boss portion 171 supports, from the inner peripheral side toward the outer peripheral side, the inner peripheral surface of the insertion hole of the cutting blade 121 mounted on the boss portion 171 of the receiving flange 170, on the outer peripheral surface of the portion on the rear end side in the axial direction. The boss portion 171 is formed with a male screw 175 that engages with a screw hole 181 having a female screw formed on the inner periphery of the nut 180, on the outer periphery of the portion on the front end side in the axial direction.

[0025] When the cutting blade 121 is mounted on the receiving flange 170, the flange portion 172 is a flat support surface 176 parallel to the surface orthogonal to the axial direction, formed on a part of the surface on the front end side in the axial direction, and supports the side surface of the mounted cutting blade 121 facing the rear end side in the axial direction, from the rear end side in the axial direction toward the front end side in the axial direction.

[0026] The cylindrical portion 173 covers the portion not covered on the outer peripheral side by the boss portion 171 and the flange portion 172, at the tip portion 126 of the rotating shaft exposed from the spindle housing 123 at the tip of the spindle 122. The cylindrical portion 173 is a portion formed according to the axial length of the tip portion 126 of the rotating shaft of the spindle 122, and may be omitted when the tip portion 126 of the rotating shaft of the spindle 122 is short.

[0027] The nut 180 is formed with a screw hole 181 having a female screw that engages with the male screw 175 of the boss portion 171, on the inner periphery. As shown in FIG. 2, after the cutting blade 121 is mounted on the receiving flange 170 mounted on the tip portion 126 of the rotating shaft of the spindle 122, the boss portion 171 of the receiving flange 170 is inserted into the screw hole 181 from the front end side in the axial direction rather than the cutting blade 121, and the screw hole 181 is screwed and fastened to the male screw 175 of the boss portion 171 of the receiving flange 170, so that a flat support surface 182 parallel to the surface orthogonal to the axial direction, formed on a part of the surface on the rear end side in the axial direction of the nut 180, contacts the side surface of the cutting blade 121 facing the front end side in the axial direction, and the cutting blade 121 is clamped between the support surface 182 of the nut 180 and the support surface 176 of the receiving flange 170, thereby fixing the cutting blade 121 to the receiving flange 170.

[0028] The bolt 190 is formed with a thread groove that engages with a threaded hole 127 formed at the tip of a portion 126 on the tip side of the rotation axis of the spindle 122. After the cutting blade 121 is fixed to the receiving flange 170 by the nut 180, the bolt 190 is inserted into the mounting hole 174 from the tip side in the axial direction and screwed into and fastened to the threaded hole 127 formed at the tip of the portion 126 on the tip side of the rotation axis of the spindle 122, thereby mounting and fixing the receiving flange 170 to the portion 126 on the tip side of the rotation axis of the spindle 122. Also, via the receiving flange 170, the cutting blade 121 fixed to the receiving flange 170 by the nut 180 is mounted and fixed to the portion 126 on the tip side of the rotation axis of the spindle 122.

[0029] The cutting device 100 sets the cutting blade 121 mounted on the tip side of the rotation axis of the spindle 122 by the moving unit 130 at a predetermined position with respect to the workpiece 200 held by the holding table 110, and relatively moves the cutting blade 121 along the division planned line 202 with respect to the workpiece 200 while rotating the cutting blade 121, thereby cutting the workpiece 200 along the division planned line 202 with the cutting blade 121.

[0030] The control unit 140 controls the operations of the respective components of the cutting device 100 to cause the cutting device 100 to perform a cutting process by the cutting unit 120. In this embodiment, the control unit 140 includes a computer system. The computer system included in the control unit 140 has an arithmetic processing unit having a microprocessor such as a CPU (Central Processing Unit), a storage device having a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and an input / output interface device. The arithmetic processing unit of the control unit 140 performs arithmetic processing according to a computer program stored in the storage device of the control unit 140, and outputs a control signal for controlling the cutting device 100 to each component of the cutting device 100 via the input / output interface device of the cutting device 100.

[0031] Next, this specification will describe the load test system 1 according to the embodiment. FIG. 3 is a functional block diagram showing a configuration example of the load test system 1 according to the embodiment. FIG. 4 is a perspective view showing a part of the load test system 1 according to the embodiment. As shown in FIG. 3, the load test system 1 according to the embodiment includes a motor under test 10, a first drive circuit 20 that drives the motor under test 10, a power supply device 30 that is connected to the first drive circuit 20 and supplies power, a load motor 40 for applying a load to the motor under test 10, a second drive circuit 50 that drives the load motor 40, and a torque measuring device 60 that measures the torque of the motor under test 10.

[0032] The motor under test 10, which is the object of the load test of the load test system 1 according to the embodiment, is a motor 125 connected to the base end portion of the spindle 122 of the cutting unit 120 in the cutting device 100. Note that the motor under test 10 is not limited to the motor 125 connected to the base end portion of the spindle 122 of the cutting unit 120 in the cutting device 100 in the present invention. Other examples include a motor connected to the base end portion of the spindle of a grinding unit in a grinding device that grinds one surface of a workpiece 200 with a grinding wheel, where the grinding wheel is rotatably mounted, or a motor connected to the base end portion of the spindle of a polishing unit in a polishing device that polishes one surface of a workpiece 200 with a polishing pad, where the mount to which the polishing pad is fixed is rotatably mounted.

[0033] As shown in FIG. 4, the motor under test 10 has a generally cylindrical rotating part 11 connected thereto. The motor under test 10 is detachably and electrically connected to the first drive circuit 20. The motor under test 10 is driven by receiving drive power from the connected first drive circuit 20 to rotate the rotating part 11. In this embodiment, the rotating part 11 rotated by the motor under test 10 is the tip-side portion 126 of the rotating shaft exposed by the spindle housing 123 of the spindle 122 rotated by the motor 125. Note that the rotating part 11 rotated by the motor under test 10 is the tip-side portion of the rotating shaft of the spindle when the motor under test 10 is a motor connected to the base end portion of the spindle of the grinding unit of the grinding device, and is the tip-side portion of the rotating shaft of the spindle when the motor under test 10 is a motor connected to the base end portion of the spindle of the polishing unit of the polishing device.

[0034] As shown in FIG. 3, the first drive circuit 20 is electrically connected to the power supply device 30 and is detachably and electrically connected to the motor under test 10. The first drive circuit 20 is supplied with AC power from the power supply device 30, converts the supplied AC power into AC drive power to be supplied to the motor under test 10, and supplies the drive power to the motor under test 10 connected to the first drive circuit 20 to drive it. It is a driver.

[0035] The power supply device 30 is electrically connected to an AC power supply 90 that supplies commercial AC power, converts the AC power supplied from the AC power supply 90 into power that can be supplied to the first drive circuit 20 and the second drive circuit 50, and supplies the converted power to the first drive circuit 20 and the second drive circuit 50. Here, the AC power supply 90 to which the power supply device 30 is electrically connected is, in this embodiment, for example, a commercial power supply of three-phase AC 200V, but the present invention is not limited to this, and it may be either single-phase AC or three-phase AC, and the voltage is not particularly limited.

[0036] In this embodiment, as shown in FIG. 3, the power supply device 30 includes a converter circuit 31, a capacitor 32, and an inverter circuit 33. One side of the converter circuit 31 is electrically connected to an AC power supply 90, and the capacitor 32 is disposed on the other side. The converter circuit 31 converts the AC power supplied from the AC power supply 90 into DC power and supplies it to the capacitor 32. The capacitor 32 is disposed between the converter circuit 31 and the inverter circuit 33 and supplies the DC power supplied from the converter circuit 31 to the inverter circuit 33. Further, the capacitor 32 is electrically connected to the converter circuit 51 of the second drive circuit 50 and supplies the DC regenerative power supplied from the converter circuit 51 of the second drive circuit 50 to the inverter circuit 33. One side of the inverter circuit 33 has the capacitor 32 disposed thereon, and the other side is electrically connected to the first drive circuit 20 and the second drive circuit 50, respectively. The inverter circuit 33 converts the DC power supplied from the converter circuit 31 via the capacitor 32 and the DC regenerative power supplied from the converter circuit 51 of the second drive circuit 50 into AC power and supplies the AC power to the first drive circuit 20 and the second drive circuit 50. The inverter circuit 33 controls the voltage or frequency of the AC power supplied to each of the first drive circuit 20 and the second drive circuit 50.

[0037] As shown in Fig. 4, the load motor 40 has a generally cylindrical load portion 41 connected thereto. The load portion 41 is formed in a shape and size that fits with the rotating portion 11 of the motor under test 10. The load motor 40 is electrically connected to the second drive circuit 50. As shown in Fig. 4, the load motor 40 has the rotating portion 11 of the motor under test 10 fitted to the load portion 41, and is driven by the drive power supplied from the second drive circuit 50, so that a load is applied to the motor under test 10 from the load portion 41 via the rotating portion 11. Further, with the rotating portion 11 of the motor under test 10 fitted to the load portion 41, the motor under test 10 is driven by the drive power supplied from the first drive circuit 20 to rotate the rotating portion 11, and a rotational force is applied to the load portion 41 along with the rotation of the rotating portion 11, thereby generating AC regenerative power. Thus, the AC regenerative power is generated by the load motor 40 when the motor under test 10 is driven. The load motor 40 supplies the AC regenerative power generated in this way to the converter circuit 51 of the second drive circuit 50.

[0038] As shown in Fig. 3, the second drive circuit 50 is electrically connected to the power supply device 30 and electrically connected to the load motor 40. The second drive circuit 50 is supplied with AC power from the power supply device 30, converts the supplied AC power into AC drive power to be supplied to the load motor 40, and is a driver that supplies drive power to the load motor 40 connected to the second drive circuit 50 to drive it.

[0039] As shown in FIG. 3, the second drive circuit 50 has a converter circuit 51. The converter circuit 51 is electrically connected to the capacitor 32 and the load motor 40, respectively. The converter circuit 51 is supplied with AC regenerative power from the load motor 40, converts the AC regenerative power supplied from the load motor 40 into DC regenerative power, and supplies the DC regenerative power to the capacitor 32. In this way, the second drive circuit 50 converts the AC regenerative power generated by the load motor 40 into DC regenerative power and supplies it to the capacitor 32 of the power supply device 30. Then, when the test motor 10 is driven, the power supply device 30 supplies the AC regenerative power generated by the load motor 40 to the power supply device 30 via the second drive circuit 50.

[0040] The torque measuring device 60 is provided connected to the test motor 10 and measures the torque of the test motor 10. The torque measuring device 60 can cause an operator who performs an electrical load test on the test motor 10 using the load test system 1 to recognize the measured torque of the test motor 10, for example, by displaying the measured torque of the test motor 10 on a display unit (not shown) in a visible manner to the operator.

[0041] The operation of the load test system 1 according to the embodiment having the above configuration will be described. First, in the load test system 1 according to the embodiment, the rotating part 11 of the motor under test 10, which is the object of the load test, is fitted to the load part 41 of the load motor 40, the motor under test 10 is electrically connected to the first drive circuit 20, and the converter circuit 31 side of the power supply device 30 is electrically connected to the AC power supply 90, whereby preparations for performing a load test on the motor under test 10 are made. Next, in the load test system 1 according to the embodiment, the power supply device 30 supplies driving power to the motor under test 10 through the first drive circuit 20 to drive the motor under test 10 and rotates the rotating part 11 at a predetermined rotational speed, supplies driving power to the load motor 40 through the second drive circuit 50 to drive the load motor 40, and applies a load to the motor under test 10 via the load part 41 and the rotating part 11. At this time, a torque test as a load test on the motor under test 10 is performed by measuring the torque of the motor under test 10 with the torque measuring device 60.

[0042] In the load test system 1 according to the embodiment, the load motor 40 generates AC regenerative power when a rotational force is applied to the load motor 40 by the motor under test 10 via the load part 41 and the rotating part 11, and supplies the AC regenerative power to the converter circuit 51 of the second drive circuit 50. The converter circuit 51 of the second drive circuit 50 converts this AC regenerative power into DC regenerative power and supplies the DC regenerative power to the capacitor 32. The power supply device 30 converts this DC regenerative power into AC regenerative power by the inverter circuit 33 and supplies the AC regenerative power to the first drive circuit 20 and the second drive circuit 50.

[0043] Conventionally, since the driving power for driving the motor is consumed as heat by the resistance of the load motor, only useless thermal energy is discharged, resulting in high power consumption and high running costs being a problem. However, in the load test system 1 according to the embodiment having the above configuration, since the regenerative power generated in the load motor 40 by driving the motor under test 10 is supplied to the power supply device 30 via the second drive circuit 50, a part of the driving power for driving the motor under test 10 is recovered as the regenerative power generated in the load motor 40 and reused for the driving power for driving the motor under test 10. Therefore, it has the effect of reducing power consumption and running costs compared to the prior art.

[0044] Also, the load test system 1 according to the embodiment includes a converter circuit 31 connected to the AC power supply 90, an inverter circuit 33 for controlling the voltage or frequency of the first drive circuit 20, and a capacitor 32 disposed between the converter circuit 31 and the inverter circuit 33. The regenerative power generated in the load motor 40 is supplied to the capacitor 32 of the power supply device 30. For this reason, in the load test system 1 according to the embodiment, since the regenerative power is supplied where the power supplied from the AC power supply 90 is converted into DC power, the fear that the power from the AC power supply 90 is interfered with by the regenerative power and the power amount decreases or the frequency changes can be suppressed.

[0045] Also, in the load test system 1 according to the embodiment, further, the second drive circuit 50 converts the AC power generated in the load motor 40 into DC power and supplies it to the power supply device 30. For this reason, in the load test system 1 according to the embodiment, since the DC regenerative power is supplied where the power supplied from the AC power supply 90 is converted into DC power, the fear that the power from the AC power supply 90 is interfered with by the regenerative power and the power amount decreases or the frequency changes is further suppressed, and the regenerative power can be effectively reused in the same manner as the power from the AC power supply 90.

[0046] Next, the inventor of the present invention confirmed the operational effects of the load test system 1 according to the embodiment. FIG. 5 is a diagram for explaining the operational effects of the load test system 1 according to the embodiment. FIG. 5 collectively shows the results obtained when the operational effects were confirmed.

[0047] In the column of "Comparative Example" on the left side of FIG. 5, the power consumption when a load test on the motor under test 10 was performed using a conventional equivalent load test system in which the regenerative power generated in the load motor 40 by driving the motor under test 10 in the load test system 1 according to the embodiment was not supplied to the power supply device 30 via the second drive circuit 50 is shown. The column of "Example" on the right side of FIG. 5 shows the power consumption when a load test on the motor under test 10 was performed using the load test system 1 according to the embodiment. In both the "Comparative Example" and "Example" in FIG. 5, the same motor under test 10 was used as the object of the load test, the voltage or frequency of the AC power supplied to each of the first drive circuit 20 and the second drive circuit 50 was set to the same value, the rotational speed of the motor under test 10 was set to the same value, and the load applied to the motor under test 10 by the load motor 40 was set to the same value, and the load test was performed.

[0048] As shown in FIG. 5, when a load test on the motor under test 10 was performed using a conventional equivalent load test system, the power consumption of the load test was 2.5 kW, while when a load test on the motor under test 10 was performed using the load test system 1 according to the embodiment, the result was that the power consumption of the load test was 0.8 kW. Thus, in the example shown in FIG. 5, by supplying the regenerative power generated in the load motor 40 by driving the motor under test 10 to the power supply device 30 via the second drive circuit 50, it became clear that the power consumption can be reduced compared to the conventional equivalent, and the running cost can be reduced compared to the conventional equivalent.

[0049] Note that the present invention is not limited to the above embodiment. That is, various modifications can be made and implemented without departing from the gist of the present invention.

Explanation of Reference Numerals

[0050] 1 Load test system 10 Motor under test 20 First drive circuit 30 Power supply device 31 Converter circuit 32 Capacitor 33 Inverter circuit 40 Load motor 50 Second drive circuit 60 Torque meter 90 AC power supply

Claims

1. A load test system for performing an electrical load test on a motor under test, comprising: the motor under test; a first drive circuit for driving the motor under test; a power supply device connected to the first drive circuit for supplying power; a load motor for applying a load to the motor under test; a second drive circuit for driving the load motor; a torque measuring device for measuring the torque of the motor under test; wherein the power supply device is characterized in that electric power generated by the load motor when the motor under test is driven is supplied as regenerative power to the power supply device via the second drive circuit.

2. The power supply device comprises: a converter circuit connected to an AC power supply; an inverter circuit for controlling the voltage or frequency of the first drive circuit; a capacitor disposed between the converter circuit and the inverter circuit, and the load test system according to claim 1, wherein the regenerative power is supplied to the capacitor of the power supply device.

3. The load test system according to claim 1 or claim 2, wherein the second drive circuit is characterized in that AC power generated by the load motor is converted into DC power and supplied to the power supply device.

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