Driver

Abstract

To maintain stable signal supply to an external device related to a motor even in a case where a brake force of a dynamic brake is acting on the motor.SOLUTION: A driver supplies drive power to a motor having a prescribed number of phases and including an extraction unit that extracts a prescribed signal from supplied power and a supply unit that supplies the prescribed signal extracted by the extraction unit to an external device, or to a motor power line provided with the extraction unit and the supply unit. In the driver, a dynamic brake circuit has: a switch for switching a connection state of a power supply line to the motor in order to generate a brake force; and a prescribed circuit configured to, with respect to an input current to the dynamic brake circuit, form a prescribed high impedance state in which impedance of the dynamic brake circuit is higher when a frequency of the input current is at a prescribed frequency, compared to a case where the frequency of the input current is lower than the prescribed frequency and is within a range to which a frequency of a drive current of the motor belongs.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a driver. [Background technology]

[0002] For motors that drive loads for various purposes, the state of the motor needs to be known in order to accurately control it, and for example, an external device such as an encoder is used. In order to drive an external device such as an encoder, power and signals (information) required for processing must be supplied, and generally, a servo system (e.g., a driver) and the external device are connected by a cable, and power is supplied via the cable. As an alternative method, Patent Document 1 discloses a configuration in which the power required to drive an external device such as an encoder is superimposed on the motor's drive power and supplied to the motor once, and then the motor extracts a portion of the supplied power to supply power to the external device.

[0003] Also known is a dynamic braking technique that converts the kinetic energy of a driven motor into electrical energy to decelerate the motor. In dynamic braking, the power supply to the motor is stopped, and the motion of the rotor (moving element) of the motor is used to generate electricity, converting the kinetic energy into electrical energy, thereby decelerating the motor. In general, when deceleration is performed by dynamic braking, a large amount of electrical energy is generated in a relatively short time, so it is necessary to electrically protect the electrical circuit for the dynamic brake. For example, related techniques are disclosed in Patent Documents 2 and 3. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2022 / 186200 [Patent Document 2] JP 2002-369564 A [Patent Document 3] JP 2008-182821 A Summary of the Invention [Problem to be solved by the invention]

[0005] Although the power consumed by external devices such as an encoder attached to a motor is small compared to the power consumed by the motor itself, a stable power supply is required because the state of the driven motor needs to be constantly monitored. Power is generally supplied by wired cables, but in that case, in addition to the motor's power line, a cable for the encoder needs to be wired, which can increase the wiring workload and increase costs due to the cables. Furthermore, even when a signal (information) to be processed in an external device is supplied to the external device, using cable wiring imposes a certain amount of workload on the wiring.

[0006] Furthermore, as shown in the prior art, when a portion of the power supplied to the motor is extracted to supply a power-related signal to an external device, if dynamic braking is activated in the motor to decelerate the motor, the power supply to the motor is stopped, which also affects the signal supply to the external device. Even when dynamic braking is activated, external devices such as encoders that receive signals from the motor may need to continue to supply signals.

[0007] The present invention has been made in consideration of these problems, and has an object to provide a technique that can maintain stable signal supply to an external device related to a motor, even when a braking force is acting on the motor due to a dynamic brake. [Means for solving the problem]

[0008] The driver disclosed in the present application is a driver that supplies drive power to a motor having a predetermined number of phases, or to a motor power line provided with the extractor and the supply unit, and includes an extractor that extracts a predetermined signal from supplied power, and a supply unit that supplies the predetermined signal extracted by the extractor to an external device, and includes an output unit that generates an additional current that corresponds to the predetermined signal to be superimposed on a drive current, and superimposes the generated additional current on the drive current and outputs the superimposed current to the extractor, a dynamic braking circuit that generates a braking force by the power generation operation of the motor, and a control unit that stops the supply of drive power and activates the dynamic braking circuit to control the deceleration of the motor when a predetermined condition is satisfied. The dynamic braking circuit comprises a switch which switches the connection state of a power supply line to the motor in order to generate the braking force, and a predetermined circuit which is configured to create a predetermined high impedance state in which the impedance of the dynamic braking circuit is higher when the frequency of the input current to the dynamic braking circuit is a predetermined frequency, compared with a case in which the frequency of the input current is lower than the predetermined frequency and is in a frequency range in which the frequency of the motor drive current belongs.

[0009] There is no particular limit to the number of phases of the motor, and it may be, for example, a single-phase AC motor or a three- or more-phase AC motor. The connection of the coils in the winding section of the motor may be a so-called delta connection or a star connection (or Y connection). The coils of the winding section may be wound around the stator of the motor in a distributed winding or concentrated winding manner. In other words, there is no particular limit to the specific configuration of the winding section in the motor of the present invention.

[0010] The specific form and configuration of the extracting unit are not limited to a specific embodiment, so long as the extracting unit is arranged to extract a power signal related to power for driving an external device, or a predetermined signal that is a signal to be subjected to a predetermined process in the external device, from the windings of the motor or the power line connecting the motor and the driver. For example, the extracting unit may be arranged to form a transformer structure arranged so that a part of the power supplied to the windings of the motor or the power line is input to the primary coil, and a part of the power may be extracted as a predetermined signal through the transformer structure. The transformer structure may be either an auto-winding transformer or a compound-winding transformer. In the case of an auto-winding transformer, the secondary coil refers to a part of the primary coil that is shared by both.

[0011] Then, an AC current corresponding to the AC current flowing through the primary coil and the winding ratio (the ratio of the number of windings of the secondary coil to the number of windings of the primary coil) due to the transformer structure is extracted from the secondary coil of the transformer structure. Then, the supply unit supplies a predetermined signal based on the extracted AC current to an external device. Note that the supply unit may perform electrical processing such as rectification processing and boost processing depending on the form of supply to the external device.

[0012] Here, in order to supply power for driving the motor having the above-mentioned extracting unit and supplying unit and to supply a predetermined signal to an external device, the output unit provided in the driver outputs a current obtained by superimposing an additional current on the driving current required for driving the motor from the driver to the motor or power line. That is, a predetermined signal is extracted by the extracting unit provided in the motor from the power supplied to the motor by the output from the output unit, and the predetermined signal is supplied to the external device by the supplying unit. By adopting such a configuration, the predetermined signal can be supplied to the external device via the power supply to the motor, thereby reducing the wiring load for supplying the predetermined signal.

[0013] The driver also includes a dynamic braking circuit, which is operated by the control unit. By operating the dynamic braking circuit in a controlled manner, a braking force is generated by the power generating operation of the motor, thereby achieving deceleration control of the motor. The predetermined condition under which the dynamic braking circuit is activated by the control unit can be set as appropriate. When the dynamic braking circuit is activated, the connection state of the power supply line to the motor is changed by the switch, making it possible to generate the braking force. However, if the supply of drive power to the motor is then stopped in this state, although the motor will decelerate, the supply of predetermined signals to external devices will also be affected.

[0014]

[0023] Therefore, the dynamic braking circuit of the driver incorporates a predetermined circuit which creates a predetermined high impedance state for the input current to the circuit. This predetermined high impedance state has characteristics which depend on the frequency of the input current to the dynamic braking circuit, such that when the frequency of the input current to the dynamic braking circuit is a predetermined frequency, the impedance for the input current is higher than when the frequency is lower and in the range in which the frequency of the motor drive current belongs. In other words, the predetermined circuit creates a desired high impedance state for the input current to the dynamic braking circuit when the frequency of the input current is at or near the predetermined frequency. This makes it possible to create an electrical state in which an input current of a predetermined frequency or a frequency near the predetermined frequency can be continued to be supplied to the motor without affecting its operation or while keeping the effect on its operation as low as possible, even when the supply of drive power to the motor is stopped and the dynamic braking circuit is operated. This contributes to maintaining a stable supply of signals to an external device associated with the motor, even when a braking force due to dynamic braking is acting on the motor.

[0015]

[0023] In the above driver, when the control unit activates the dynamic braking circuit by means of the switch, the output unit may output the additional current having a frequency related to the predetermined frequency to the extractor while stopping the drive current. In other words, by utilizing the electrical characteristics (predetermined high impedance state) of the predetermined circuit described above to output an additional current having a predetermined frequency or a frequency related to the predetermined frequency, which is a frequency close to the predetermined frequency, while stopping the drive current, it is possible to supply a predetermined signal to an external device via the extractor and supply unit without affecting the operation of the dynamic braking circuit.

[0016] Here, in the driver, the additional current may be at least one of a d-axis current and a q-axis current in the drive current of the motor, and may vary over time. As an example of the change in the d-axis current or the q-axis current over time, a sinusoidal change, a rectangular change, a triangular change, or the like may be adopted.

[0017]

[0031] Furthermore, in the above driver, the predetermined frequency may be a frequency that exceeds the maximum frequency in the frequency range of the drive current of the motor. As described above, the predetermined circuit creates a high impedance state for the additional current, which is an input current of a predetermined frequency, so that the effects on the operation of the dynamic braking circuit are suitably suppressed, but further, by setting the frequency of the additional current to a frequency that exceeds the maximum frequency of the drive current of the motor, the effects on the rotational motion of the motor can be suppressed as much as possible. This means that the deceleration of the motor by the dynamic braking circuit and the supply of a predetermined signal to an external device can be controlled in an suitably separated manner.

[0018] Here, in the driver described above, the predetermined high impedance state may be an electrical characteristic such that the impedance of the dynamic braking circuit increases as the frequency of the input current to the dynamic braking circuit increases, at least in a frequency range equal to or higher than the predetermined frequency.The output section may then output the additional current, having a frequency equal to or higher than the predetermined frequency, to the extraction section while the drive current is stopped.By adopting such a configuration, it is possible to achieve a high impedance state without affecting the operation of the dynamic braking circuit. The predetermined circuit may include an inductance component to form the electrical characteristics, or may include a component other than the inductance component to form the electrical characteristics.

[0019] Furthermore, in the driver described above, the predetermined circuit may be a resonant circuit including an inductance component and a capacitance component, with the predetermined frequency as a resonant frequency, and the predetermined high impedance state may be formed in a frequency range near the predetermined frequency. The output unit may output the additional current having a frequency near the predetermined frequency to the extractor while the drive current is stopped. By adopting such a configuration, it is possible to supply a predetermined signal to an external device via the extractor and the supply unit without affecting the operation of the dynamic braking circuit. The resonant circuit may be a parallel resonant circuit including the inductance component and the capacitance component, or may be a resonant circuit of another form.

[0020]

[0023] Alternatively, the invention disclosed herein can be viewed as a dynamic braking device having a dynamic braking circuit connected to a driver that supplies drive power to a motor having a predetermined number of phases, the dynamic braking circuit comprising an extractor that extracts a predetermined signal from supplied power and a supply unit that supplies the predetermined signal extracted by the extractor to an external device, or to a motor power line provided with the extractor and the supply unit, and generating a braking force by the power generating operation of the motor. That is, in this dynamic braking device, the dynamic braking circuit is configured to comprise a switch that switches the connection state of the power supply line to the motor in order to generate the braking force, and a predetermined circuit that is configured to create a predetermined high impedance state for a current input to the dynamic braking circuit in which the impedance of the dynamic braking circuit is higher when the frequency of the input current is a predetermined frequency compared to when the frequency of the input current is lower than the predetermined frequency. When the dynamic braking device is used, it is connected to a driver for driving a motor, and when it is necessary to generate a braking force, the connection state of the power supply line to the motor is changed by the switch, and a predetermined high impedance state formed by a predetermined circuit enables a predetermined signal to be supplied to an external device via the extraction unit and the supply unit without affecting the operation of the dynamic braking circuit. Effect of the Invention

[0021] Even when a braking force due to dynamic braking is acting on the motor, a stable signal supply to an external device associated with the motor can be maintained. [Brief description of the drawings]

[0022] [Figure 1] FIG. 2 is a diagram showing a schematic configuration of a control system that controls the drive of a motor. [Diagram 2] FIG. 2 is a diagram showing a schematic configuration of a motor. [Diagram 3] FIG. 2 is a first diagram illustrating a schematic arrangement of a winding section of a motor and a transformer structure provided for the winding section. [Figure 4] FIG. 1 is a diagram showing a configuration of a dynamic braking circuit incorporated in a driver. [Figure 5A] FIG. 1 shows a first form of predetermined circuitry included in a dynamic braking circuit for creating a high impedance state for an input current to the circuit; [Figure 5B] FIG. 5B illustrates electrical characteristics associated with a high impedance state according to the given circuit shown in FIG. 5A. [Figure 6A] FIG. 11 is a diagram showing the time progression of power supply to the motor by the driver during normal operation (when the dynamic braking circuit is not in operation). [Figure 6B] FIG. 13 is a diagram showing the time progression of power supply to the motor by the driver in an emergency (when the dynamic braking circuit is activated). [Figure 7A] FIG. 1 shows a second form of predetermined circuitry included in a dynamic braking circuit for creating a high impedance state for an input current to the circuit; [Figure 7B] FIG. 7B illustrates electrical characteristics associated with a high impedance state according to the given circuit shown in FIG. 7A. [Figure 8] FIG. 2 is a second diagram illustrating the arrangement of the windings of the motor and the transformer structure provided for the windings. [Figure 9] FIG. 3 is a third diagram illustrating the arrangement of the windings of the motor and the transformer structure provided for the windings. [Figure 10] FIG. 13 is a diagram showing a schematic configuration of a motor according to a modified example. [Figure 11] FIG. 1 is a diagram showing an outline of a dynamic braking device configured separately from a driver and having a dynamic braking circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] <First embodiment> FIG. 1 is a diagram showing a schematic configuration of a control system that controls the drive of a motor. First, the control system will be described. The control system is a PLC (Programmable Logic Controller). 5 is connected to the network 1 as a higher-level controller. A plurality of servo drivers (hereinafter referred to as "drivers") 4 are connected to the network 1, and are configured to be able to send and receive signals to and from the PLC 5. Note that in FIG. 1, the functional configuration of one driver 4 is representatively described in detail, but the other drivers 4a and 4b also have functional configurations equivalent to that of the driver 4. The motor 2 is connected to the driver 4 via a power line 11 and receives a supply of driving power. Similarly, the motors 2a and 2b receive a supply of driving power from the drivers 4a and 4b via power lines 11a and 11b, respectively. Hereinafter, the structures of the motors and drivers will be described representatively based on the motor 2 and the driver 4.

[0024] Here, the motor 2 is controlled to drive a predetermined load device according to a command from the PLC 5. As an example, the load device may be various mechanical devices (for example, an arm of an industrial robot or a conveying device), and the motor 2 is incorporated in the device as an actuator for driving the load device. The motor 2 is an AC servo motor. Alternatively, the motor 2 may be an induction motor or a DC motor. The motor 2 includes a motor body 21 having a stator 213 including a winding portion 25 formed by winding a coil around a stator core and a rotor 212 incorporating a permanent magnet, and an encoder 22 having a detection disk that rotates in conjunction with the rotation of the rotor 212 and capable of detecting the rotation state of the rotor 212 (see FIG. 2). The rotation detection by the encoder 22 may be an incremental method or an absolute method.

[0025] The detection signal by the encoder 22 is wirelessly transmitted to the driver 4 via a communication unit 42 included in the driver 4, which will be described later. The transmitted detection signal is used for servo control in a control unit 41 included in the driver 4, which will also be described later. The detection signal by the encoder 22 includes, for example, position information on the rotational position (angle) of the rotating shaft of the motor 2, information on the rotational speed of the rotating shaft, and the like.

[0026] Here, the driver 4 has a control unit 41, a communication unit 42, and an output unit 43. The control unit 41 is a functional unit that manages servo control of the motor 2 based on a command from the PLC 5. The control unit 41 receives an operation command signal related to the operation (motion) of the motor 2 from the PLC 5 via the network 1 and a detection signal output from the encoder 22, and calculates servo control related to the drive of the motor 2, i.e., a command value related to the operation of the motor 2. The control unit 41 executes feedback control using a position controller, a speed controller, and a current controller. The control unit 41 is also configured to manage controls other than the servo control of the motor 2 that are performed by the driver 4.

[0027] The communication unit 42 is a functional unit that manages wireless communication between the encoder 22 and the driver 4. When starting wireless communication, the communication unit 42 of the driver 4 identifies the encoder 22 as the target of wireless communication by a process of identifying the encoder with which the communication unit 42 is to communicate. Therefore, the communication unit 42 does not cross-connect with the encoder of the motor 2a or the encoder of the motor 2b and perform wireless communication. Similarly, the encoder of the motor 2a and the encoder of the motor 2b perform wireless communication only with the drivers 4a and 4b, respectively. The output unit 43 supplies driving power to the motor 2 through the power line 11 based on a command value regarding the operation of the motor 2 calculated by the control unit 41. Note that, to generate this supply power, AC power sent from the AC power source 7 to the driver 4 is used. The AC power sent from the AC power source 7 is converted to DC by a converter in the output unit 43, and is further converted to DC by an inverter in the output unit 43 so as to become driving power suitable for driving the motor 2, and is supplied to the motor 2 through the power line 11. Furthermore, the output unit 43 also serves to output a predetermined signal to the encoder 22, etc., as described below. In this embodiment, the driver 4 is of a type that receives three-phase AC, but may be of a type that receives single-phase AC. Alternatively, the driver 4 may be of a type that receives DC.

[0028] Next, the schematic configuration of the motor 2 will be described with reference to FIG. 2. The motor 2 is a three-phase (U-phase, V-phase, W-phase) AC motor, and includes a motor body 21 and an encoder 22. The motor body 21 includes a rotor 212 and a stator 213. A permanent magnet is incorporated in the rotor 212 and is supported rotatably. The stator 213 includes a winding section 25 formed by winding a coil around a stator core formed of electromagnetic steel sheets. In this embodiment, the connection of each phase in the winding section 25 is Y-connection, but it may be delta-connection instead. In this embodiment, the coil may be wound around the stator core by either distributed winding or concentrated winding. The configuration shown in FIG. 2 is merely schematic, and the technical idea of ​​the present invention can be applied regardless of the specific configuration of the motor.

[0029] The power line 11 for supplying driving power from the driver 4 is connected to the connector 211. The connector 211 is connected to each phase of the winding section 25. In the motor 2, a transformer structure (see 53, 63, and 73 shown in FIG. 3; details will be described later) is arranged for the winding section 25, and an extractor 214 is provided that uses the transformer structure to extract a part of the driving power supplied to the coil of the winding section 25 as a predetermined signal to be supplied to the encoder. That is, the extractor 214 extracts a current that can be used as a driving current for the encoder 22 on the secondary coil side by passing the AC current flowing through the winding section 25 of the motor body 21 to the primary coil side of the transformer structure. In this embodiment, the predetermined signal extracted by the extractor 214 is a power signal related to the driving power of the encoder 22, that is, the predetermined signal itself is provided for driving the encoder 22.

[0030] The extraction unit 214 extracts the power due to the AC current output from the secondary coil of the transformer structure as power (predetermined signal) for the encoder 22. There, the power is rectified by the supply unit 215, and the voltage is increased or decreased to a DC voltage suitable for driving the encoder 22 by a DC-DC converter included in the supply unit 215 as necessary. Then, in a state where the encoder 22 is attached to the motor body 21, the supply unit 215 is electrically connected to the encoder 22 so that the supply unit 215 can supply DC power to the encoder 22 side, particularly to the processing unit 221 that performs a detection process of the rotation of the rotor 212. The supply unit 215 may also have a secondary battery that can store the rectified DC power. In that case, power can be supplied to the encoder 22 even during a period when no drive current flows through the winding unit 25 or during a period when the drive current is extremely low.

[0031] In addition, in the motor 2 of this embodiment, the extraction process by the extraction unit 214 is used to extract the motor main body. The winding unit 21 is also configured to enable transmission and reception of another type of predetermined signal different from the above-mentioned predetermined signal (power signal related to the driving power of the encoder 22) between the winding unit 25 of the body 21 and the processing unit 221 of the encoder 22. An example of the other predetermined signal is a signal provided for processing in the processing unit 221 of the encoder 22. The transmission and reception of the other predetermined signal is realized by the signal exchange unit 216 using the above-mentioned transformer structure.

[0032] When sending a predetermined signal (a power signal related to the drive power of the encoder 22 or a signal to be processed in the processing unit 221) from the winding unit 25 to the processing unit 221, the output unit 43 of the driver 4 outputs a current obtained by superimposing an additional current corresponding to the predetermined signal on a drive current for driving the motor 2 to the coil of the winding unit 25, and this current flows through the primary coil side of the transformer structure, so that the extraction unit 214 can extract and generate a current corresponding to the predetermined signal on the secondary coil side of the transformer structure. Then, the supply unit 215 and the signal exchange unit 216 pass this extracted predetermined signal to the processing unit 221.

[0033] In addition, when sending a predetermined signal from the processing unit 221 to the winding unit 25, a current including the predetermined signal is passed through the secondary coil of the transformer structure via the signal exchange unit 216, so that the extraction unit 214 generates a current corresponding to the predetermined signal on the primary coil of the transformer structure, and the current can be passed through the coil of the winding unit 25. In this case, the signal exchange unit 216 may also perform a predetermined amplification process on the predetermined signal. Since the coil of the winding unit 25 is electrically connected to the driver 4 via the power line 11, the predetermined signal can be transmitted from the encoder 22 to the driver 4 via a current corresponding to the predetermined signal output from the processing unit 221. As described above, the encoder 22 and the driver 4 are configured to be able to communicate wirelessly via the communication unit 42, but it is considered that the transmission and reception of the predetermined signal via the signal exchange unit 216 is useful under certain conditions, such as a state before the wireless communication is possible.

[0034] Next, the winding section 25 of the motor body 21 and the arrangement of the transformer structure provided for the winding section 25 will be described with reference to Fig. 3. The winding section 25 includes three-phase winding sections L5, L6, and L7 for U, V, and W phases. The winding sections for each phase are connected in a Y-connection, and the joints of the winding sections are neutral points. For the U-phase winding section L5, the inductance component is indicated by 51 and the resistance component is indicated by 52 in Fig. 3. Similarly, for the V-phase winding section L6, the inductance component is indicated by 61 and the resistance component is indicated by 62, and further, for the W-phase winding section L7, the inductance component is indicated by 71 and the resistance component is indicated by 72.

[0035] A transformer structure forming the extractor 214 is disposed in each phase. Specifically, in the U phase, the primary coil 531 of the transformer structure 53 of the U phase is connected in series to the winding portion L5, in the V phase, the primary coil 631 of the transformer structure 63 of the V phase is connected in series to the winding portion L6, and in the W phase, the primary coil 731 of the transformer structure 73 of the W phase is connected in series to the winding portion L7. The secondary coil 532 of the transformer structure 53 of the U phase, the secondary coil 632 of the transformer structure 63 of the V phase, and the secondary coil 732 of the transformer structure 73 of the W phase are connected to the supply unit 215. Furthermore, each of the secondary coils 532, 632, and 732 is also connected to the signal exchange unit 216.

[0036] The winding ratio (ratio of the number of windings of the secondary coil to the number of windings of the primary coil) of the transformer structure of each phase is basically the same, but may be different. In the embodiment shown in FIG. 3, a transformer structure is arranged for all three phases, and its secondary coil is connected to the supply unit 215 and the signal exchange unit 216, but a transformer structure may be arranged for only some of the three phases, and its secondary coil may be connected to the supply unit 215 and the signal exchange unit 216. Alternatively, a transformer structure may be arranged for all three phases, and the secondary coils of some of the transformer structures may be connected to the supply unit 215, and the secondary coils of the remaining transformer structures may be connected to the signal exchange unit 216. In this case, the supply unit 2 The turns ratio of the transformer structure connected to the signal exchange unit 215 and responsible for supplying power to the encoder 22, and the turns ratio of the transformer structure connected to the signal exchange unit 216 and responsible for transmitting and receiving predetermined signals to and from the encoder 22 may be appropriately set according to the respective purposes.

[0037] By employing the winding section 25 and transformer structures 53, 63, 73 configured in this manner, a portion of the power supplied to the motor 2 via the power line 11 can be extracted by the extraction section 214 as a signal that serves as driving power for the encoder 22 or as a signal to be provided for processing by the encoder 22. With this configuration, when the motor 2 is running, the power of the encoder 22 is always supplied stably, and since there is no need to wire a cable to the encoder 22 for this purpose, the work of wiring the cables can be greatly reduced and the costs can be kept down.

[0038] Here, the circuit equations of motor 2 in the form shown in Fig. 3, in which a single-phase transformer is used as the transformer structure, will be considered. The characteristics of the transformer structure of each phase are the same. In the equations shown below, voltages Vu, Vv, Vw, and currents Iu, Iv, Iw represent the output voltage and current of each phase of driver 4, Lu, Lv, Lw represent the self-inductance of each phase of motor 2, and Muv, Mvw, Mwu represent the mutual inductance between phases of motor 2. Also, ωe represents the electrical angular frequency, Φuvw represents the maximum number of flux linkages in the armature winding, R represents the winding resistance, Ke represents the induced voltage constant, and s is a differential operator. Also, voltages Vux2, Vvx2, Vwx2, and current The currents Iux2, Ivx2, and Iwx2 represent the output voltage and current of the secondary side of the transformer structure, Lx1, Lx2, and Mx represent the primary inductance, secondary inductance, and mutual inductance of the transformer structure, respectively, Rx1 and Rx2 represent the winding resistances of the primary and secondary sides of the transformer structure, and θe is an electrical angle.

[0039] The circuit equations of the motor 2 are expressed by the following Equations 1 and 2.

number

number

[0040] Furthermore, by performing a conversion process from three phases of UVW to two phases of dq, and a conversion process from a fixed coordinate system to a rotating coordinate system, the circuit equations shown in the following Equations 3 and 4 are obtained.

number

number

[0041] Furthermore, the secondary power Pdqx of the transformer structure is expressed by the following formula 5. Moreover, the d-axis current idx2 and the q-axis current iqx2 on the secondary side of the transformer structure are expressed by the following formula 6. Note that in the formulas shown below, RL represents the load resistance of an external device (encoder 22) to which power is supplied via the transformer structure forming the extraction unit 214.

number

number

[0042] Based on Equations 5 and 6, the power Pdqt of the steady-state characteristics on the secondary side of the transformer structure is expressed by the following Equation 7.

number

[0043] As can be seen from Equation 7, the power extracted by the transformer structure is determined by the d-axis current id and the q-axis current iq supplied to the motor 2 from the driver 4 via the power line 11, and the electrical angular frequency ωe related to the rotational speed of the motor. Since the d-axis current id and the q-axis current iq should be supplied from the driver 4 to the motor 2 to bring it into the desired operating state, i.e., into a state where the desired torque is generated at the desired rotational speed, the extraction unit 214 is designed to minimize the effect on the operating state of the motor 2 as much as possible.

[0044] As shown in Fig. 4, the driver 4 is provided with a dynamic braking circuit 80. The dynamic braking circuit 80 is connected in parallel to a U-phase line 401, a V-phase line 402, and a W-phase line 403 which connect the output side of an inverter included in the driver 4 and the motor 2 (power line 11). The dynamic braking circuit 80 is a braking circuit which decelerates the motor 2 by generating a braking force using the power generation operation of the motor 2. In the dynamic braking circuit 80, a first short-circuit line 81 connected to the U-phase line 401 and a second short-circuit line 83 connected to the V-phase line 402 are wired via a switch 82, and the second short-circuit line 83 and a third short-circuit line 84 connected to the W-phase line 403 are wired via a switch 85. A predetermined circuit 90 (described later) is provided in the first short-circuit line 81, and the same predetermined circuit 90 is also provided in the third short-circuit line 84.

[0045]

[0043] When the dynamic braking circuit 80 is not in operation, the switches 82 and 85 are in the off state. As a result, the first short-circuit line 81, the second short-circuit line 83, and the third short-circuit line 84 are electrically isolated from each other, and no braking force is generated by the dynamic braking circuit 80. On the other hand, when the dynamic braking circuit 80 is in operation, the switches 82 and 85 are all in the on state, and as a result, the connection states of the U-phase line 401, the V-phase line 402, and the W-phase line 403 are switched. In other words, the power supply lines to each phase are short-circuited, and power is generated by the rotation of the motor 2, thereby generating the above-mentioned braking force and decelerating the motor 2. Note that when the dynamic braking circuit 80 is in operation, as a general rule, the power supply to the motor 2 is stopped in order to decelerate the motor 2. The dynamic braking circuit 80 is a known technique, and its circuit configuration is not limited to the form shown in FIG. 4, and dynamic braking circuits of other forms are also applicable to the present disclosure.

[0046] An example of a condition under which the dynamic braking circuit 80 operates is when, in the system shown in FIG. 1, an emergency stop button or the like is pressed, requiring the drive of the motor 2 and the like to be stopped immediately. In such a case, the control unit 41 of the driver 4 detects the pressing of the emergency stop button, which triggers the supply of drive power from the output unit 43 to the motor 2 to be stopped, and the control unit 41 switches the switches 82, 85 included in the dynamic braking circuit 80 from the OFF state to the ON state. As a result, the U-phase line 401, the V-phase line 402, and the W-phase line 403 are short-circuited, thereby realizing deceleration by the power generation operation of the motor 2. On the other hand, if the supply of drive power from the output unit 43 is completely stopped at this time, the power of the additional current corresponding to the predetermined signal superimposed on the drive power will also no longer be supplied to the motor 2, and the predetermined signal to the processing unit 221 of the encoder 22 (a signal related to the drive power of the encoder 22, and a signal to be processed within the encoder 22) will be transmitted to the processing unit 221 of the encoder 22. Even if the dynamic braking circuit 80 brings the motor 2 to an emergency stop, it may be preferable to continue to supply drive power, etc. to the encoder 22 in order to grasp the state of the motor 2.

[0047]

[0043] Therefore, the dynamic braking circuit 80 is provided with a predetermined circuit 90 so that, even when the dynamic braking circuit 80 is in operation, the predetermined signal can be supplied to the encoder 22 via the extractor 214 of the motor 2 while suitably decelerating the motor 2. As shown in Figure 5A, the predetermined circuit 90 has a resistance component 91 and an inductance component 92 connected in series. The resistance component 91 is an element for consuming the electrical energy produced by the power generating operation of the motor 2, and the magnitude of the resistance component 91 can be selected appropriately in accordance with the deceleration distance of the motor 2. The inductance component 92 is an element for adjusting the impedance characteristics with respect to the input current to the dynamic braking circuit 80 to the characteristics shown in Figure 5B. Alternatively, the predetermined circuit 90 can be configured without including the resistance component 91.

[0048] The impedance characteristic shown in Figure 5B is such that the impedance of the dynamic braking circuit 80 increases as the frequency increases, and in particular, when the frequency is f1, the impedance of the dynamic braking circuit 80 is Z1. This impedance Z1 is set to be sufficiently high to ensure that a predetermined signal is supplied to the encoder 22. Furthermore, the frequency f1 is set to be sufficiently high compared to the maximum frequency in the frequency range of the drive current of the motor 2, i.e., the frequency corresponding to the maximum rotational speed of the motor 2. Thus, with respect to the impedance characteristic shown in Figure 5B, when the frequency of the input current is within the frequency range of the drive current of the motor 2 (a frequency related to the rotational speed of the motor 2), the impedance of the dynamic braking circuit 80 with respect to that input current is sufficiently low, and when the frequency of the input current is f1 or higher, the impedance of the dynamic braking circuit 80 is Z1 or higher.

[0049]

[0046] Here, the supply of power by the output unit 43 for providing a predetermined signal from the driver 4 to the encoder 22 via the extraction unit 214 of the motor 2 will be described with reference to Figures 6A and 6B. Figure 6A shows an example of the progression of the q-axis current over time (upper part (a)) and an example of the progression of the d-axis current over time (lower part (b)) when the dynamic braking circuit 80 is not operating, i.e., when the switches 82, 85 in the circuit are in the off state. These q-axis current and d-axis current are currents in a state in which an additional current corresponding to the predetermined signal is superimposed on a drive current for driving the motor 2 in a desired state. Therefore, in the motor 2 to which these q-axis current and d-axis current are supplied from the driver 4, the extraction unit 214 extracts the predetermined signal.

[0050] The q-axis current shown in FIG. 6A does not change over time and has a constant value Iq1, while the d-axis current changes over time with a constant bias Id1 applied. The fluctuation width (amplitude) of the d-axis current is ΔId, and its frequency fd is f1 shown in FIG. 5B. The bias Id1 of the d-axis current is a drive current required to drive the motor 2 in a desired state, and a current expressed in a form that varies over time with respect to the drive current is an additional current corresponding to a predetermined signal, and the d-axis current finally supplied to the motor 2 is the drive current to which the additional current is superimposed. In addition, the transformer structure constituting the extractor 214 is designed so that the extraction efficiency when the current of the above frequency f1 is input is a suitable value. Therefore, by varying the d-axis current value that becomes the additional current over time in this manner, it is possible to maintain a high efficiency of power extraction by the transformer structure, thereby realizing efficient supply of a predetermined signal to the encoder 22.

[0051] Next, the power supply when the dynamic braking circuit 80 is activated is shown in FIG. 6B. Figure 6B shows an example of the progression of the q-axis current over time (upper part (a)) and the d-axis current over time (lower part (b)) when the dynamic braking circuit 80 is activated, that is, when the switches 82 and 85 in the circuit are in the on state. As can be seen from a comparison of Figures 6A and 6B, activation of the dynamic braking circuit 80 stops the supply of the drive current for driving the motor 2. Therefore, the value of the q-axis current becomes zero, and with regard to the d-axis current, its bias component Id1 also becomes zero. However, with regard to the d-axis current, a current that changes over time (a current with a frequency f1 and an amplitude ΔId) corresponding to the above-mentioned additional current continues to flow.

[0052]

[0046] Here, the presence of the predetermined circuit 90 in the dynamic braking circuit 80 results in the impedance characteristic shown in Figure 5B. Therefore, when the dynamic braking circuit 80 is in operation, the current generated by the power generation due to the rotation of the motor is processed by the dynamic braking circuit 80, and the dynamic braking circuit 80 exhibits a sufficiently high impedance Z1 with respect to the d-axis current shown in Figure 6B(b), so that the effect of this current on the dynamic braking circuit 80 is designed to be extremely small. As a result, this current is supplied to the motor 2 even when the dynamic braking circuit 80 is in operation, making it possible to supply a predetermined signal to the encoder 22 via the extractor 214, and ensuring proper operation of the encoder 22.

[0053] <Second embodiment> In this embodiment, the circuit shown in Figure 7A is used as the specified circuit 90. As shown in Figure 7A, the specified circuit 90 has a configuration in which a resistance component 91 and a parallel resonant circuit formed by an inductance component 92 and a capacitance component are connected in series. Like the specified circuit 90 shown in Figure 5A, the resistance component 91 is an element for consuming the electrical energy generated by the power generating operation of the motor 2, and the magnitude of the resistance component 91 can be selected appropriately in accordance with the deceleration distance of the motor 2. The inductance component 92 and the capacitance component 93 are elements for setting the impedance characteristics with respect to the input current to the dynamic braking circuit 80 to the characteristics shown in Figure 7B.

[0054] The impedance characteristic shown in Figure 7B has a peak shape such that the impedance of the dynamic braking circuit 80 is Z1 or greater when the frequency of the input current to the dynamic braking circuit 80 is in the vicinity of a frequency f1 that is sufficiently higher than the maximum frequency in the frequency range of the drive current of the motor 2, i.e., the frequency corresponding to the maximum rotational speed of the motor 2. The impedance Z1 is synonymous with the shape shown in Figure 5B. Thus, the impedance characteristic shown in Figure 7B shows that when the frequency of the input current is within the frequency range resulting from the rotational speed of the motor 2, the impedance of the dynamic braking circuit 80 with respect to that input current is essentially zero, and when the frequency of the input current is within a region with a width Δf centered on f1, the impedance of the dynamic braking circuit 80 is Z1 or greater.

[0055] This frequency f1 corresponds to the frequency of the d-axis current that changes over time, as shown in Figures 6A and 6B. Therefore, in this embodiment too, by configuring the output unit 43 to output the q-axis current and the d-axis current shown in Figure 6A when the dynamic braking circuit 80 is not operating, and by configuring the output unit 43 to output the q-axis current and the d-axis current shown in Figure 6B when the dynamic braking circuit 80 is operating, it is possible, as in the first embodiment, to supply a predetermined signal to the encoder 22 via the extractor 214 when the dynamic braking circuit 80 is not operating, and furthermore, it is possible to supply a predetermined signal to the encoder 22 via the extractor 214 even when the dynamic braking circuit 80 is operating.

[0056] <Modification> A modified example of the transformer structure forming the extractor 214 will be described with reference to FIGS. 8 and 9. First, a first embodiment of the modified example will be described with reference to FIG. 8. The configuration of the winding section 25 of the motor body 21 is the same as that of the embodiment shown in FIG. 3, and therefore a detailed description thereof will be omitted. In this embodiment, the primary coil 531 of the transformer structure 53 corresponding to the U phase is connected in parallel to the winding parts L5, L6, and L7 of the three phases, the primary coil 631 of the transformer structure 63 corresponding to the V phase is connected in parallel, and the primary coil 731 of the transformer structure 73 corresponding to the W phase is connected in parallel. In detail, the line L50 including the primary coil 531, the line L60 including the primary coil 631, and the line L70 including the primary coil 731 are Y-connected, and the other ends are connected to the winding part L5 of the U phase, the winding part L6 of the V phase, and the winding part L7 of the W phase, respectively. The secondary coil 532 of the transformer structure 53, the secondary coil 632 of the V-phase transformer structure 63, and the secondary coil 732 of the W-phase transformer structure 73 are connected to the supply unit 215. Furthermore, each of the secondary coils 532, 632, and 732 is also connected to the signal exchange unit 216.

[0057] In this embodiment, the winding ratio of the transformer structure of each phase is basically the same, but may be different. In the embodiment shown in FIG. 8, a transformer structure corresponding to all three phases is arranged, and its secondary coil is connected to the supply unit 215 and the signal exchange unit 216. However, a transformer structure may be arranged to correspond to only some of the three phases, and its secondary coil may be connected to the supply unit 215 and the signal exchange unit 216. Alternatively, a transformer structure corresponding to all three phases may be arranged, and the secondary coil of some of the transformer structures may be connected to the supply unit 215, and the secondary coil of the remaining transformer structures may be connected to the signal exchange unit 216. In this case, the winding ratio of the transformer structure connected to the supply unit 215 and controlling the power supply to the encoder 22 and the winding ratio of the transformer structure connected to the signal exchange unit 216 and controlling the transmission and reception of a predetermined signal to and from the encoder 22 may be suitably set according to the respective purposes.

[0058] By employing the winding section 25 and transformer structures 53, 63, 73 configured in this manner, it is possible for the extractor 214 to extract a predetermined signal from the power supplied to the motor 2 via the power line 11, and supply the predetermined signal to the encoder 22. Furthermore, by providing the dynamic braking circuit 80 having the predetermined circuit 90 described above on the driver 4 side, it is possible to supply a predetermined signal to the encoder 22 via the extractor 214 even when the dynamic braking circuit 80 is operating.

[0059] Next, a second embodiment of the modified example will be described with reference to FIG. 9. The configuration of the winding section 25 of the motor body 21 is the same as that of the above embodiment, and therefore a detailed description thereof will be omitted. However, in this embodiment, the coil components 51, 61, 71 of the winding parts L5, L6, L7 of each phase are used as the primary coils 531, 631, 731 of the transformer structures 53, 63, 73 corresponding to each phase. In detail, in the U phase, the coil component 51 is used as the primary coil 531 to form the transformer structure 53, in the V phase, the coil component 61 is used as the primary coil 631 to form the transformer structure 63, and in the W phase, the coil component 71 is used as the primary coil 731 to form the transformer structure 73. Therefore, in the third embodiment, the secondary coils 532, 632, 732 of the transformer structures 53, 63, 73 of each phase are wound around the stator core together with the main coils of the winding section, which are also the primary coils, to form the transformer structures 53, 63, 73 of each phase. The secondary coil 532 of the transformer structure 53, the secondary coil 632 of the V-phase transformer structure 63, and the secondary coil 732 of the W-phase transformer structure 73 are connected to the supply unit 215. Furthermore, each of the secondary coils 532, 632, and 732 is also connected to the signal exchange unit 216.

[0060] In this embodiment, the winding ratio of the transformer structure of each phase is basically the same, but may be different. In the embodiment shown in FIG. 9, the transformer structure corresponding to all three phases is arranged, and the secondary coil is connected to the supply unit 215 and the signal exchange unit 216. However, the transformer structure may be arranged to correspond to only some of the three phases, and the secondary coil may be connected to the supply unit 215. 215 and the signal exchanging unit 216. Alternatively, transformer structures corresponding to all three phases may be arranged, with the secondary coils of some of the transformer structures connected to the supply unit 215 and the secondary coils of the remaining transformer structures connected to the signal exchanging unit 216. In this case, the turns ratio of the transformer structure connected to the supply unit 215 and responsible for supplying power to the encoder 22 and the turns ratio of the transformer structure connected to the signal exchanging unit 216 and responsible for sending and receiving a predetermined signal to and from the encoder 22 may be suitably set according to the respective purposes.

[0061] By employing the winding section 25 and transformer structures 53, 63, 73 configured in this manner, it is possible for the extractor 214 to extract a predetermined signal from the power supplied to the motor 2 via the power line 11, and supply the predetermined signal to the encoder 22. Furthermore, by providing the dynamic braking circuit 80 having the predetermined circuit 90 described above on the driver 4 side, it is possible to supply a predetermined signal to the encoder 22 via the extractor 214 even when the dynamic braking circuit 80 is operating.

[0062] Furthermore, although the transformer structures 53, 63, and 73 shown in Figures 3, 8, and 9 are compound-winding transformer structures, a single-winding transformer structure may be adopted as a modified example. For example, when a single-winding transformer structure is adopted in the form shown in Figure 9, the winding section 25 of the motor 2 is used as a primary coil and a part of the winding section 25 is used as a secondary coil to form the transformer structures 53, 63, and 73. In other words, the secondary coil portion of the winding section 25 is shared between the primary side and the secondary side.

[0063] Furthermore, in the above-described embodiments, a three-phase AC motor has been exemplified as the motor 2, but the number of phases of the motor 2 is not limited to three. For example, a motor with three or more phases may also be used. In that case, too, it is preferable to provide an extraction unit 214 corresponding to the number of phases used, and to also provide a dynamic braking circuit on the driver 4 side corresponding to the number of phases used.

[0064] <Modifications regarding the device to which the extracted power is supplied> In the above-described embodiment, the predetermined signal extracted by the extraction unit 214 is supplied to the encoder 22, but the extracted predetermined signal can also be supplied to devices other than the encoder 22. For example, a predetermined signal related to power may be supplied to a sensor device (such as a temperature sensor or a vibration sensor) disposed inside or outside the motor 2. In this case, a port suitable for supplying the predetermined signal and serving as a connection port for a cable to the sensor may be provided in the motor body 21.

[0065] <Modifications regarding power extraction> This modified example will be described with reference to FIG. 10. FIG. 10 is a diagram showing a schematic configuration of a motor 2 according to this modified example. The motor 2 according to this embodiment is provided with an extractor 214 having a transformer structure for a winding portion 25, as in the embodiment shown in FIG. 2. The transformer structure of the extractor 214 can be substantially the same as that shown in FIG. 3, FIG. 8, and FIG. 9. Furthermore, in this modified example, an extractor 214b capable of extracting power is provided for the power line 11 connected to the connector 211. The power extraction by the extractor 214b is also achieved by incorporating a transformer structure electrically the same as that shown in FIG. 3, etc., in the power line 11.

[0066] The predetermined signal extracted by the extraction unit 214b can be supplied as power to devices such as a temperature sensor or vibration sensor arranged outside the motor 2. The extracted power can be stored in a secondary battery, thereby enabling stable power to be supplied to the temperature sensor, etc. In the motor 2 shown in FIG. 10, the predetermined signal extracted by the extraction unit 214 is supplied to the encoder 22, but instead, the predetermined signal extracted by the extraction unit 214b can be supplied to the encoder 22. The input signal may be supplied to the input 22.

[0067] In this way, in the motor 2 disclosed herein, it is possible to extract a predetermined signal not only from the windings 25 but also from the power lines 11 and supply the predetermined signal to the encoder 22, an external sensor, etc., thereby significantly reducing the wiring load for supplying power to the servo system. Furthermore, by providing the dynamic braking circuit 80 having the above-mentioned predetermined circuit 90 on the driver 4 side, it is possible to supply a predetermined signal to the encoder 22 via the extraction section 214 even when the dynamic braking circuit 80 is operating.

[0068] <Modifications regarding the dynamic braking circuit>

[0046] In the above-described embodiments, the dynamic braking circuit 80 is provided inside the driver 4. Alternatively, as shown in Figure 11, the dynamic braking circuit 80 may be provided inside a dynamic braking device 140 that is distinct from the driver 4. In the dynamic braking device 140, the dynamic braking circuit 80 is connected to power supply lines that are respectively connected to a U-phase line 401, a V-phase line 402, and a W-phase line 403 in the driver 4. The dynamic braking device 140 is also electrically connected to a control unit 41 of the driver 4. When the control unit 41 of the driver 4 detects that a condition for activating the dynamic braking circuit 80 is met, the switches 82, 85 of the dynamic braking device 140 are controlled by a command from the control unit 41.

[0069] Even if the dynamic braking device 140 and the driver 4 are configured separately in this manner, the output section 43 of the driver 4 can effectively drive the motor 2 and supply a predetermined signal to the encoder 22 by supplying the q-axis current and the d-axis current shown in Figures 6A and 6B when the dynamic braking circuit 80 is inactive and active, respectively.

[0070] <Appendix 1> A driver (4) for supplying drive power to a motor (2) having a predetermined number of phases, or to a motor power line (11) provided with the extraction unit (214) and the supply unit (215), the driver (4) comprising: an extraction unit (214) for extracting a predetermined signal from supplied power; and a supply unit (215) for supplying the predetermined signal extracted by the extraction unit (214) to an external device (22), an output section (43) that generates an additional current corresponding to the predetermined signal to be superimposed on the drive current, superimposes the generated additional current on the drive current, and outputs the result to the extraction section; a dynamic braking circuit (80) that generates a braking force by the power generating operation of the motor; a control unit (41) that stops the supply of drive power and activates the dynamic braking circuit when a predetermined condition is satisfied, thereby performing deceleration control of the motor; and Equipped with The dynamic braking circuit (80) comprises: a switch (82, 85) for switching a connection state of a power supply line to the motor in order to generate the braking force; a predetermined circuit (90) configured to create a predetermined high impedance state in which the impedance of the dynamic braking circuit is higher when the frequency of the input current to the dynamic braking circuit (80) is a predetermined frequency, compared with a state in which the frequency of the input current is lower than the predetermined frequency and is in a frequency range in which the frequency of the drive current of the motor belongs; , a driver. <Appendix 2> When the control unit (41) activates the dynamic braking circuit (80) by the switches (82, 85), the output unit (43) outputs the additional current having a frequency related to the predetermined frequency to the extraction unit (214) while stopping the drive current. and output it, Drivers listed in Appendix 1. <Appendix 3> The additional current is at least one of a d-axis current and a q-axis current in the drive current of the motor, and is a current that varies over time. Drivers listed in Appendix 2. <Appendix 4> The predetermined frequency is a frequency exceeding a maximum frequency within a frequency range of a drive current of the motor. Drivers listed in Appendix 2. <Appendix 5> the predetermined high impedance state is an electrical characteristic in which the impedance of the dynamic braking circuit (80) increases as the frequency of the input current to the dynamic braking circuit (80) increases, at least in a frequency range equal to or higher than the predetermined frequency, The output unit (43) outputs the additional current having a frequency equal to or higher than the predetermined frequency to the extraction unit (214) while the driving current is stopped. A driver as defined in any one of Appendix 2 to Appendix 4. <Appendix 6> The predetermined circuit (90) includes an inductance component (92) to form the electrical characteristics. Drivers listed in Appendix 5. <Appendix 7> The predetermined circuit is a resonant circuit including an inductance component (92) and a capacitance component (93) and having the predetermined frequency as a resonant frequency, The predetermined high impedance state is formed in a frequency region near the predetermined frequency, The output unit (43) outputs the additional current having a frequency close to the predetermined frequency to the extraction unit (214) while the driving current is stopped. A driver as defined in any one of Appendix 2 to Appendix 4. <Appendix 8> the resonant circuit is a parallel resonant circuit formed by the inductance component (92) and the capacitor component (93); Drivers listed in Appendix 7. <Appendix 9> The predetermined signal is a power signal related to power for driving the external device (22) or a signal to be subjected to a predetermined process in the external device. A driver as defined in any one of Appendix 1 to Appendix 4. <Appendix 10> a dynamic braking device (140) including a dynamic braking circuit (80) connected to a driver (4) that supplies drive power to a motor (2) having a predetermined number of phases, the dynamic braking circuit (80) including an extraction unit (214) that extracts a predetermined signal from supplied power, and a supply unit (215) that supplies the predetermined signal extracted by the extraction unit (214) to an external device (22), or to a motor power line (11) provided with the extraction unit (214) and the supply unit (215), and generating a braking force by a power generating operation of the motor (2), The dynamic braking circuit (80) comprises: a switch (82, 85) for switching a connection state of the coil of the motor in order to generate the braking force; a predetermined high impedance state is formed in the dynamic braking circuit (80) in which the impedance of the dynamic braking circuit is higher when the frequency of the input current to the dynamic braking circuit (80) is a predetermined frequency than when the frequency of the input current is lower than the predetermined frequency; A predetermined circuit (90) configured as described above; A dynamic braking device comprising: [Explanation of symbols]

[0071] 2 Motors 4 Servo driver 22 Encoder 25 Winding section 53, 63, 73 Transformer structure 80 Dynamic Brake Circuit 90 Predetermined circuit 91 Resistance Component 92 Inductance Component 93 Capacitor Components 140 Dynamic Brake Device 214 Extraction part 215 Supply section

Claims

1. A driver that supplies drive power to a motor having a predetermined number of phases, or to a motor power line provided with the extraction unit and the supply unit, the driver comprising: an extraction unit that extracts a predetermined signal from supplied power; and a supply unit that supplies the predetermined signal extracted by the extraction unit to an external device, the driver comprising: an output section that generates an additional current corresponding to the predetermined signal to be superimposed on a drive current, superimposes the generated additional current on the drive current, and outputs the result to the extraction section; a dynamic braking circuit that generates a braking force by a power generating operation of the motor; a control unit that stops the supply of drive power and activates the dynamic braking circuit when a predetermined condition is satisfied, thereby performing deceleration control of the motor; and Equipped with The dynamic braking circuit comprises: a switch for switching a connection state of a power supply line to the motor in order to generate the braking force; a predetermined circuit configured to create a predetermined high impedance state in which the impedance of the dynamic braking circuit is higher when the frequency of the input current to the dynamic braking circuit is a predetermined frequency, compared with when the frequency of the input current is lower than the predetermined frequency and is in a frequency range in which the frequency of the drive current for the motor belongs; , a driver.

2. when the control unit activates the dynamic braking circuit by using the switch, the output unit outputs the additional current having a frequency related to the predetermined frequency to the extraction unit while stopping the drive current. The driver of claim 1 .

3. The additional current is at least one of a d-axis current and a q-axis current in the drive current of the motor, and is a current that varies over time. The driver of claim 2 .

4. The predetermined frequency is a frequency exceeding a maximum frequency within a frequency range of a drive current of the motor. The driver of claim 2 .

5. the predetermined high impedance state is an electrical characteristic in which the impedance of the dynamic braking circuit increases as the frequency of the input current to the dynamic braking circuit increases, at least in a frequency range equal to or higher than the predetermined frequency, the output unit outputs the additional current having a frequency equal to or higher than the predetermined frequency to the extraction unit while the driving current is stopped. A driver according to any one of claims 2 to 4.

6. The predetermined circuit has the electrical characteristics formed by including an inductance component. A driver as claimed in claim 5.

7. The predetermined circuit is a resonant circuit including an inductance component and a capacitance component, and having the predetermined frequency as a resonant frequency, The predetermined high impedance state is formed in a frequency region near the predetermined frequency, the output unit outputs the additional current having a frequency close to the predetermined frequency to the extraction unit while the drive current is stopped. A driver according to any one of claims 2 to 4.

8. the resonant circuit is a parallel resonant circuit formed by the inductance component and the capacitance component; A driver as claimed in claim 7.

9. The predetermined signal is a power signal related to power for driving the external device, or a signal to be subjected to a predetermined process in the external device. A driver according to any one of claims 1 to 4.

10. 1. A dynamic braking device having a dynamic braking circuit connected to a driver that supplies drive power to a motor having a predetermined number of phases, the dynamic braking circuit comprising an extractor that extracts a predetermined signal from supplied power, and a supplying unit that supplies the predetermined signal extracted by the extractor to an external device, or to a motor power line provided with the extractor and the supplying unit, and generating a braking force by a power generating operation of the motor, The dynamic braking circuit comprises: a switch for switching a connection state of a power supply line to the motor in order to generate the braking force; a predetermined circuit configured to create a predetermined high impedance state in response to an input current to the dynamic braking circuit, in which the impedance of the dynamic braking circuit is higher when the frequency of the input current is a predetermined frequency than when the frequency of the input current is lower than the predetermined frequency; A dynamic braking device comprising:

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