Rotating electrical machine
Patent Information
- Application Number
- JP2025561947
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Priority Date
- 2023-12-07
- Filing Date
- 2024-12-06
- Publication Date
- 2025-06-12
AI Technical Summary
Existing rotating electrical machines require a prototype mode to set optimal control conditions during actual work, which is inefficient and disrupts continuous operation.
A rotating electrical machine with a control unit that automatically adjusts the input current to the motor body based on the rotational speed and torque, allowing optimal control during actual work without a prototype mode.
The machine achieves optimal control conditions automatically during actual work, ensuring efficient operation and maintaining a good cutting edge state while reducing power consumption.
Abstract
Description
Rotating electric machines
[0001] The present invention relates to a rotating electrical machine that controls the rotation speed in accordance with the load state.
[0002] Patent Document 1 describes a power tool that has a work mode that is used when actually performing work and a prototype mode that is used to estimate the work mode.
[0003] The power tool of Patent Document 1 executes a prototype mode before entering a work mode. The power tool of Patent Document 1 estimates the work mode based on the motor characteristic values acquired in the prototype mode. Then, during actual work, the power tool of Patent Document 1 drives the motor using the estimated work mode.
[0004] Japanese Patent Application Laid-Open No. 2020-001147
[0005] However, with the power tool of Patent Document 1, in order to set optimal control conditions for actual work, the prototype mode must be executed before the work is carried out.
[0006] Therefore, an object of the present invention is to automatically set optimal control conditions during actual work and control the drive of a motor.
[0007] A rotating electric machine according to one embodiment of the present invention is a rotating electric machine mounted on an electric cutting tool equipped with a cutter, and includes a motor main body that transmits rotational force to the cutter, and a control unit that controls an input current to the motor main body.
[0008] The control unit controls the input current to the motor so that the motor operates at the maximum rotation speed during no-load operation in the startup state. When the cutting machine starts cutting the cutting object, a load is applied to the motor, and the rotation speed reaches an initial stable state, the control unit controls the input current to the motor so that the rotation speed is maintained.
[0009] The control unit increases the input current when the rotation speed decreases after the initial stable state in a region where the input current does not reach the limit upper limit value, and decreases the input current when the rotation speed continues for more than the switching threshold time.
[0010] With this configuration, when the cutting tool is not sharp enough to cut the object (for example, when the blade is jammed), the rotation speed decreases, so the input current can be increased and the torque can be increased. This improves the cutting quality of the object. On the other hand, when the cutting tool is lightly cutting the object, the rotation speed can be increased, so the input current is decreased and the rotation speed is increased. This reduces power consumption while roughly maintaining a good cutting quality. Therefore, optimal control according to the cutting condition of the object is achieved.
[0011] According to this invention, optimum control conditions can be automatically set during actual work, and the drive of the motor can be optimally controlled.
[0012] FIG. 1 is a diagram illustrating an example of functional blocks of a rotating electric machine according to a first embodiment of the present invention. FIG. 2 is a graph illustrating an example of a characteristic pattern (torque curve) representing the relationship between the torque and rotation speed of a motor main body in an unloaded state. FIGS. 3A and 3B are graphs illustrating an example of a characteristic pattern (torque curve) representing the relationship between the torque and rotation speed of a rotating electric machine according to the first embodiment. FIG. 4 is a flowchart illustrating a first control example executed by a controller of the rotating electric machine according to the first embodiment. FIG. 5 is a flowchart illustrating a second control example executed by a controller of the rotating electric machine according to the first embodiment. FIG. 6 is a diagram illustrating an example of functional blocks of a rotating electric machine according to a second embodiment of the present invention. FIG. 7 is a flowchart illustrating an example of a method for generating a database of disconnection load characteristic patterns. FIG. 8A is a flowchart illustrating an example of control during disconnection according to the second embodiment, and FIG. 8B is a flowchart illustrating an example of control with an update function for the database of disconnection load characteristic patterns. FIG. 9 is a flowchart illustrating an example of machine learning for a rotating electric machine according to a third embodiment. FIG. 10 is a flowchart illustrating an example of database update by machine learning for a rotating electric machine according to the third embodiment.
[0013] [First Embodiment] A rotating electric machine according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a diagram showing an example of functional blocks of a rotating electric machine according to the first embodiment of the present invention.
[0014] As shown in FIG. 1 , the rotating electrical machine 10 includes a motor body 20 , a control unit 30 , a rotation speed measurement sensor 41 , a current sensor 42 , and a power supply 90 .
[0015] Although the specific configuration of the rotating electric machine 10 is not shown, it is mounted on an electric cutting tool equipped with a cutter. The electric cutting tool is assumed to be a tool that cuts an object using circular motion without converting the circular motion of the rotating electric machine into linear motion using a rack and pinion or the like, specifically an electric chainsaw or circular saw.
[0016] A specific example of the motor body 20 is a brushless DC motor. The motor body 20 transmits rotational force to the cutter.
[0017] 2 is a graph showing an example of a characteristic pattern (torque curve) that shows the relationship between the torque and rotation speed of the motor body under no load. As shown in Fig. 2, the characteristic pattern of the motor body 20 shows that the torque decreases as the rotation speed increases, and conversely, the torque increases as the rotation speed decreases.
[0018] The maximum rotation speed depends on the input voltage of the motor body 20, and the higher the input voltage, the higher the maximum rotation speed. The maximum torque depends on the input current of the motor body 20, and the higher the input current, the higher the maximum torque.
[0019] The control unit 30 is connected to the motor main body 20. The control unit 30 generates a drive signal for the motor main body 20 using power supplied from the power supply 90 and outputs it to the motor main body 20. The motor main body 20 rotates in response to the input drive signal, and this rotation is transmitted to the cutter. At this time, the motor main body 20 generates a rotation speed and torque according to the input current and input voltage in accordance with the characteristic pattern. The cutter operates based on these rotation speed and torque.
[0020] The rotation speed measurement sensor 41 measures the rotation speed of the motor main body 20. The rotation speed measurement sensor 41 outputs the measured rotation speed to the control unit 30.
[0021] The current sensor 42 is disposed on a conductive cable connecting the control unit 30 and the motor main body 20. The current sensor 42 measures the current value of the drive signal, i.e., the current value of the input current of each phase to the motor main body 20 (hereinafter, the current value of the input current will be simply referred to as the "input current"). The current sensor 42 outputs the measured input current to the control unit 30. The control unit 30 references the input current to perform various types of control (e.g., control to stabilize the rotation speed, etc.), which will be described later.
[0022] The control unit 30 controls the input current to the motor main body 20 based on the number of rotations measured by the rotation number measurement sensor 41 and the input current measured by the current sensor 42 .
[0023] Specifically, the control unit 30 executes the following control.
[0024] 3A and 3B are graphs showing an example of a characteristic pattern (torque curve) representing the relationship between torque and rotation speed of the rotating electric machine according to the first embodiment, where Fig. 3A shows an example of a transition of an operating point due to a change in load, and Fig. 3B is a diagram showing an output at each operating point.
[0025] When the rotating electric machine 10 is in a start-up state, the control unit 30 controls the motor body 20 so that it operates at the no-load operating point in the maximum characteristic pattern (characteristic pattern under no-load conditions), as shown in Fig. 3A. More specifically, the control unit 30 controls the input voltage according to the rated voltage of the motor body 20, and controls the input current so that the motor body 20 operates at the maximum rotation speed during no-load operation. Ideally, torque becomes zero (input current becomes zero) during no-load operation, but because of resistance losses in the bearings and driving losses in the cutting blade, the operating point of the maximum rotation speed is where a slight torque is generated, as shown in Fig. 3A.
[0026] A user begins cutting a target (e.g., wood) using the cutter of an electric cutting tool. When the cutter comes into contact with the target, the load on the motor 20 increases compared to when it is unloaded, and the rotation speed decreases. That is, the operating point moves to a position (initial operating point) within the region surrounded by the maximum characteristic pattern where the rotation speed of the motor 20 is appropriate for the target. At this time, the control unit 30 measures the change in rotation speed and increases the input current according to the change. The appropriate rotation speed is determined, for example, by a rotation speed at which torque sufficient to cut the target can be obtained and the target can be cut as quickly as possible at a stable speed.
[0027] In this way, at the initial operating point, a predetermined initial load is applied to the motor body 20, the rotation speed becomes an appropriate rotation speed, and the torque becomes an appropriate torque, so that the motor body 20 enters an initial stable state.
[0028] When cutting is continued after the initial stable state is reached, if the rotation speed and torque in the initial stable state continue to be suitable for cutting the object to be cut (if cutting can be continued stably), the initial stable state will be maintained.
[0029] In this state, the control unit 30 maintains the input current without changing it, thereby maintaining the initial stable state and allowing the cutting machine to cut the object while maintaining sharpness.
[0030] However, the state of the cutting target is not necessarily constant depending on the site.
[0031] As a result, the first change is that the part of the cutting object becomes softer, and in this case, the cutting object can be cut stably with lower torque and higher rotation speed.
[0032] If the duration of the initial stable state is equal to or longer than the switching threshold, the control unit 30 controls to reduce the input current. As a result, as shown in Figure 3(A), the changed operating point under light load shifts the initial operating point on the disconnection load characteristic pattern toward a higher rotation speed (lower torque). The disconnection load characteristic pattern is a characteristic pattern that is parallel to the maximum characteristic pattern, passes through the initial operating point, and has the same maximum torque as the maximum characteristic pattern (see Figures 3(A) and 3(B)).
[0033] By performing such control, the motor main body 20 is driven at a higher rotational speed, and the cutting speed of the cutting object can be increased. Also, by reducing the input current, the power consumption of the motor main body 20 is reduced.
[0034] A second change is that the part to be cut may harden. In this case, the cutting speed of the part to be cut may slow down or the part may become unable to be cut at the initial stable rotation speed and torque. When this occurs, the rotation speed of the motor main body 20 decreases.
[0035] The control unit 30 detects a decrease in the rotation speed and controls the input current to be increased in a region where the input current does not reach the upper limit value. As a result, as shown in Figure 3A, the changed operating point under heavy load shifts the initial operating point to the higher torque side (lower rotation speed side) on the cutoff load characteristic pattern.
[0036] Then, the control unit 30 increases the input current until, for example, a rotation speed equivalent to the rotation speed of the motor main body 20 at the initial operating point is obtained. By performing such control, the motor main body 20 can obtain a high input current, resulting in a higher torque and enabling the cutting object to be cut more reliably.
[0037] In these controls, the operating point moves on the disconnection load characteristic pattern, and the output at the initial operating point (torque x rotation speed: area SO in Figure 3(B)), the output at the changed operating point under light load (torque x rotation speed: area SH in Figure 3(B)), and the output at the changed operating point under heavy load (torque x rotation speed: area SL in Figure 3(B)) are the same.
[0038] In this way, the rotating electric machine 10 automatically switches to high rotation and low torque drive if it is possible to cut the object to be cut at a higher speed while maintaining a constant output, and automatically switches to high torque and high rotation drive if the object to be cut is not sharp enough (for example, the blade is jammed).
[0039] As a result, the rotating electric machine 10 can automatically set optimal control conditions according to the state of the cutting target and optimally control the drive of the motor main body 20. Therefore, the rotating electric machine 10 can automatically set optimal control conditions during actual work and optimally control the drive of the motor main body 20 without having to run a prototype mode in advance.
[0040] To perform the above control, the rotating electrical machine 10 performs control based on the flowchart shown in FIG. 4 or 5, for example.
[0041] FIG. 4 is a flowchart showing a first control example executed by the control unit of the rotating electrical machine according to the first embodiment.
[0042] The control unit 30 controls the rotation speed (input current control) of the motor main body 20 to the maximum rotation speed (S11).
[0043] The rotation speed sensor 41 measures the rotation speed at a predetermined cycle and outputs the measured value to the control unit 30 (S12). The control unit 30 sequentially acquires the rotation speed and sequentially calculates the time derivative of the rotation speed (the amount of change in the rotation speed per unit time).
[0044] If the rotation speed has not decreased (S13: NO), the control unit 30 continues the rotation speed control at the maximum rotation speed.
[0045] When the rotation speed decreases (S13: YES), the control unit 30 increases the input current. Then, when the torque increases and the rotation speed becomes constant and stable, the control unit 30 controls the rotation speed to maintain the stable state (S14).
[0046] The control unit 30 continues to detect the rotation speed. If the rotation speed decreases (S15: YES), the control unit 30 increases the input current, and when the rotation speed reaches a next stable state, controls the rotation speed to maintain the stable state (S14). That is, if the rotation speed decreases, the control unit 30 sets the input current higher to increase the torque and stabilize the rotation speed.
[0047] If the rotation speed has not decreased for the switching threshold time or longer (S15: NO), the control unit 30 performs rotation speed control at the maximum rotation speed (the same maximum rotation speed as in step S11) (S16).
[0048] If the rotation speed decreases after the rotation speed control to the maximum rotation speed in step S16 (S17: YES), the control unit 30 returns to step S14, and after the rotation speed becomes constant and reaches a stable state (a new stable state different from the initial stable state), it controls the rotation speed to maintain the stable state (S14).
[0049] If the rotation speed does not decrease for a predetermined time after the rotation speed control to the maximum rotation speed in step S16 (S17: NO), the control unit 30 determines, for example, that the motor is in an unloaded state and that disconnection has been completed. In this case, for example, the control unit 30 may stop supplying the drive signal to the motor body 20. This allows the rotating electric machine 10 to achieve further power savings.
[0050] Fig. 5 is a flowchart showing a second control example executed by the control unit of the rotating electric machine according to the first embodiment. In the flowchart shown in Fig. 5, the control from step S11 to step S15 is the same as in the flowchart shown in Fig. 4. Therefore, a description of the same parts will be omitted.
[0051] If the rotation speed has not decreased for the switching threshold time or longer (S15: NO), the control unit 30 controls to increase the rotation speed (S16A). The amount of increase in the rotation speed (the newly set rotation speed) can be set appropriately.
[0052] If the rotation speed temporarily drops after the control to increase the rotation speed in step S16A (S17: YES), the control unit 30 returns to step S14, and after the rotation speed becomes constant and reaches a stable state (a new stable state different from the initial stable state), it controls the rotation speed to maintain the stable state (S14).
[0053] If the rotation speed does not decrease for a predetermined time after the control to increase the rotation speed in step S16A (S17: NO), the control unit 30 continues to control the rotation speed to increase (S16A) until the set rotation speed reaches the maximum rotation speed (S18: NO).
[0054] When the rotation speed reaches the maximum rotation speed (S18: YES) and the maximum rotation speed is maintained for a predetermined time, the control unit 30 determines that, for example, a no-load state has been reached and cutting has ended.
[0055] In this way, by executing the first control example shown in Figure 4 or the second control example shown in Figure 5, the rotating electric machine 10 can automatically set the optimal control conditions according to the state of the object to be cut, and optimally control the drive of the motor main body 20.
[0056] Second Embodiment A rotating electric machine according to a second embodiment of the present invention will be described with reference to the drawings. Fig. 6 is a diagram showing an example of functional blocks of the rotating electric machine according to the second embodiment of the present invention.
[0057] 6, the rotating electric machine 10A according to the second embodiment differs from the rotating electric machine 10 according to the first embodiment in that control is performed based on a plurality of types of cutoff load characteristic patterns. Other configurations of the rotating electric machine 10A according to the second embodiment are the same as those of the rotating electric machine 10 according to the first embodiment, and therefore, a description of similar parts will be omitted.
[0058] The rotating electrical machine 10A includes a control unit 30A and a storage unit 300.
[0059] The storage unit 300 stores a database of disconnection load characteristic patterns. The database of disconnection load characteristic patterns is made up of a plurality of types of disconnection load characteristic patterns.
[0060] The cutting load characteristic pattern is set for each type of cutting object and each type of condition of the cutting object. The type of cutting object refers to the material of the cutting object (metal, wood, concrete, asphalt, etc.) or even the type of the same material (e.g., type of wood). The condition of the cutting object refers to, for example, dry or wet wood.
[0061] FIG. 7 is a flowchart showing an example of a method for generating a database of cutting load characteristic patterns.
[0062] The control unit 30A acquires a characteristic pattern relating to the cutting object from a series of relationships between rotation speed and torque (a series of load state fluctuation patterns) obtained by the control shown in the first embodiment (S201).
[0063] The control unit 30A stores the acquired characteristic pattern in the storage unit 300 together with the operation mode (for example, the name of the object to be cut, etc.) (S202).
[0064] By performing this process for each disconnection target, a database of disconnection load characteristic patterns is generated in the storage unit 300.
[0065] Using the database of the cutting load characteristic patterns thus generated, the control unit 30A performs control as follows.
[0066] FIG. 8A is a flowchart showing an example of control during disconnection according to the second embodiment.
[0067] The control unit 30A acquires multiple relationships between the rotation speed and torque (multiple load state fluctuation patterns) obtained by the current control (S211). For example, the control unit 30A acquires the initial operating point and the operating points set multiple times thereafter.
[0068] The control unit 30A estimates the current cutoff load characteristic pattern from the acquired multiple relationships between rotation speed and torque (acquired load state fluctuation pattern) using, for example, linear approximation (S212).
[0069] The control unit 30A compares the current disconnection load characteristic pattern with a plurality of disconnection load characteristic patterns stored in the storage unit 300 (S213).
[0070] The control unit 30A selects the cut load characteristic pattern that is most similar to the current cut load characteristic pattern as the optimal characteristic pattern. For example, the control unit 30A selects the cut load characteristic pattern that has the shortest distance between the line representing the current cut load characteristic pattern and the lines representing the multiple cut load characteristic patterns as the optimal characteristic pattern.
[0071] In the control following step S211, the control unit 30A uses the optimal characteristic pattern (optimal pattern operating mode) to control the input current so as to automatically change the operating point according to the state of the above-mentioned cutting object (S214).
[0072] By performing such control, the rotating electrical machine 10A can automatically set optimal control conditions according to the object to be cut, and can optimally control the drive of the motor main body 20.
[0073] If the optimum characteristic pattern is not found at this time, the database of the disconnection load characteristic pattern can be updated as shown in Fig. 8(B), which is a flowchart showing an example of control with an updating function for the database of the disconnection load characteristic pattern.
[0074] Steps S211 to S213 in FIG. 8B are the same as those in FIG. 8A, and therefore will not be described here.
[0075] If there is a cut load characteristic pattern similar to the current cut load characteristic pattern (S220: YES), the control unit 30A selects it as the optimum characteristic pattern (S221). For example, if there is a cut load characteristic pattern whose line-to-line distance is within a predetermined threshold value compared to the current cut load characteristic pattern, the control unit 30A selects it as the optimum characteristic pattern.
[0076] In the control following step S211, the control unit 30A uses the optimal characteristic pattern (optimal pattern operating mode) to control the input current so as to automatically change the operating point according to the state of the above-mentioned cutting object (S214).
[0077] If there is no cut load characteristic pattern similar to the current cut load characteristic pattern (S220: NO), the control unit 30A continues to execute the current control. For example, if there is no cut load characteristic pattern in which the above-mentioned line distance is within the predetermined threshold value for the current cut load characteristic pattern, the control unit 30A determines that there is no optimal characteristic pattern.
[0078] The control unit 30A additionally stores the current cutoff load characteristic pattern obtained after the current series of controls is completed as a new operating mode (S222).
[0079] This allows the control unit 30A to update the database of the cutting load characteristic pattern.
[0080] [Third embodiment] A rotating electric machine according to a third embodiment of the present invention will be described with reference to the drawings. The rotating electric machine according to the third embodiment differs from the rotating electric machine according to the second embodiment in that the control unit 30A has a machine learning function. The other configurations of the rotating electric machine according to the third embodiment are the same as those of the rotating electric machine according to the second embodiment, and a description of the same parts will be omitted.
[0081] In general, the control unit 30A performs machine learning to output a cutoff load characteristic pattern using the relationship between torque and rotation speed (a series of load state fluctuation patterns in the motor main body 20) acquired over a predetermined time period as input.
[0082] FIG. 9 is a flowchart illustrating an example of machine learning for a rotating electric machine according to the third embodiment.
[0083] The control unit 30A acquires, as a characteristic pattern, a series of load state fluctuation patterns in the motor main body 20 (S31). If the number of times that machine learning is possible has not been reached (S32: NO), the control unit 30A repeats acquiring the characteristic pattern.
[0084] If the number of times that machine learning is possible has been reached (S32: YES), the control unit 30A classifies the acquired multiple characteristic patterns into multiple operating patterns (multiple types of disconnection load characteristic patterns) based on the similarity of the multiple characteristic patterns (S33).
[0085] The control unit 30A estimates the disconnection load characteristic pattern for each operating pattern by performing linear approximation using the least squares method using multiple operating points of multiple characteristic patterns classified as the same type, and generates a database of load characteristic patterns (S34).
[0086] The control unit 30A can also update the database of generated load characteristic patterns by machine learning.
[0087] FIG. 10 is a flowchart illustrating an example of updating a database by machine learning for a rotating electric machine according to the third embodiment.
[0088] The control unit 30A acquires a series of load state fluctuation patterns in the motor main body 20 as a characteristic pattern (S301). The control unit 30A refers to a database of load characteristic patterns stored in the storage unit 300 (S302). The control unit 30A determines whether there is a load characteristic pattern similar to the currently acquired characteristic pattern (similar pattern).
[0089] If there is a similar pattern (S303: YES), the control unit 30A re-estimates similar load characteristic patterns, including the current characteristic pattern, and updates the database of load characteristic patterns (S304).
[0090] If there is no similar pattern (S303: NO), the control unit 30A adds the current characteristic pattern to the database as a new load characteristic pattern (operation pattern) (S305).
[0091] By performing such processing, the rotating electrical machine 10A can use machine learning to create a more suitable database of load characteristic patterns.
[0092] <1> A rotating electric machine mounted on an electric cutting tool equipped with a cutter, the rotating electric machine comprising: a motor main body that transmits rotational force to the cutter; and a control unit that controls an input current to the motor main body, wherein the control unit controls the input current so that the motor main body operates at a maximum rotation speed during no-load operation in a start-up state; when the cutter starts cutting an object to be cut and a load is applied to the motor main body, thereby reaching an initial stable rotation speed, the control unit controls the input current to the motor main body to maintain the rotation speed; and in a region where the input current does not reach a limited upper limit value, when the rotation speed decreases after reaching the initial stable state, the control unit increases the input current; and when the rotation speed continues for more than a switching threshold time, the control unit decreases the input current.
[0093] <2> The rotating electric machine according to <1>, wherein the control unit controls the input current to correspond to the maximum rotation speed when the rotation speed continues for the switching threshold time or longer.
[0094] <3> The rotating electric machine according to <1> or <2>, wherein the control unit controls the input current based on a cutting load characteristic pattern that represents a relationship between torque and rotation speed according to an object to be cut by the cutting machine.
[0095] <4> A rotating electric machine according to <3>, further comprising a memory unit that stores a plurality of types of the cutoff load characteristic patterns, wherein the control unit acquires torque and rotation speed based on the input current for a predetermined period of time, selects the optimum cutoff load characteristic pattern from the plurality of types of the cutoff load characteristic patterns based on the torque and rotation speed acquired for the predetermined period of time, and controls the input current based on the selected cutoff load characteristic pattern.
[0096] <5> The rotating electric machine according to <4>, wherein the control unit updates the plurality of types of cutoff load characteristic patterns stored in the memory unit by performing machine learning using the torque and rotation speed acquired for the predetermined time as input and outputting the cutoff load characteristic pattern.
[0097] 10, 10A: Rotating electric machine 20: Motor body 30, 30A: Control unit 41: Rotation speed measurement sensor 42: Current sensor 90: Power supply 300: Storage unit
Claims
1. A rotating electric motor mounted on an electric cutting tool equipped with a cutter, comprising: a motor body that transmits rotational force to the cutter; and a control unit that controls an input current to the motor body, wherein the control unit controls the input current so that the motor body operates at its maximum rotation speed during unloaded operation in a starting state, controls the input current to the motor body to maintain the rotation speed when the cutter starts cutting an object to be cut and a load is placed on the motor body, resulting in an initial stable rotation speed, and controls the input current to the motor body to maintain the rotation speed when the rotation speed decreases after the initial stable state in a region where the input current does not reach a limited upper limit value, and reduces the input current when the rotation speed continues for a switching threshold time or longer.
2. The rotating electric machine according to claim 1, wherein said control unit controls said input current to correspond to said maximum rotation speed when said rotation speed continues for more than said switching threshold time.
3. A rotating electric machine according to claim 1 or 2, wherein the control unit controls the input current based on a cutting load characteristic pattern that represents the relationship between torque and rotation speed according to an object to be cut by the cutting machine.
4. A rotating electric motor as described in claim 3, further comprising a memory unit which stores a plurality of types of the cut-off load characteristic patterns, wherein the control unit acquires torque and rotation speed based on the input current for a predetermined period of time, selects an optimum cut-off load characteristic pattern from the plurality of types of the cut-off load characteristic patterns based on the torque and rotation speed acquired for the predetermined period of time, and controls the input current based on the selected cut-off load characteristic pattern.
5. The rotating electric machine according to claim 4, wherein the control unit updates the multiple types of cut-off load characteristic patterns stored in the memory unit by performing machine learning using the torque and rotation speed acquired for the specified period of time as input and outputting the cut-off load characteristic pattern.