Power conversion device, diagnostic device, and diagnostic method

Abstract

To provide a technique capable of more appropriately diagnosing deterioration abnormality of an AC motor.SOLUTION: A power conversion device 100 according to an embodiment of the present disclosure includes: an inverter circuit 130 that drives an AC motor using power input from the outside; a sensor 150 that detects a phase current of an electric motor M; a power calculation unit 1402 that calculates at least one of active power and reactive power of the electric motor M on the basis of the output of the sensor 150; and a diagnosis unit 1405 that diagnoses deterioration abnormality of the electric motor M on the basis of a frequency component of at least one of the active power and the reactive power.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present disclosure relates to a power conversion device and the like. [Background technology]

[0002] For example, there is known a technique for diagnosing deterioration or abnormality of an AC motor based on the active power and reactive power of the AC motor (see Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6777251 [Patent Document 2] Patent No. 6818155 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned document, the deterioration abnormality of the AC motor is diagnosed by focusing on the magnitude of the active power and reactive power of the AC motor. Therefore, for example, there is a possibility that an erroneous diagnosis is made that there is a possibility of a deterioration abnormality by capturing an instantaneous change in the magnitude of the active power and reactive power of the AC motor. In addition, there is a possibility that it is not possible to diagnose a deterioration abnormality that is not reflected in the magnitude of the active power and reactive power of the AC motor. As a result, there is a possibility that it is not possible to appropriately diagnose a deterioration abnormality of the AC motor.

[0005] In view of the above-mentioned problems, an object of the present invention is to provide a technique that can more appropriately diagnose deterioration and abnormalities in an AC motor. [Means for solving the problem]

[0006] In order to achieve the above object, in one embodiment of the present disclosure, A drive unit that drives an AC motor using power input from an external source; A current detection unit that detects a phase current of the AC motor; a calculation unit that calculates at least one of an active power and a reactive power of the AC motor based on an output of the current detection unit; a diagnosis unit that performs a diagnosis regarding deterioration or abnormality of the AC motor based on the frequency component of at least one of the active power and the reactive power. picture, The diagnosing unit performs the diagnosis on at least one of the active power and the reactive power based on a frequency component obtained by a frequency analysis and an amplitude of vibration obtained by a waveform counting method. A power converter is provided.

[0007] In another embodiment of the present disclosure, a calculation unit that obtains an output of a current detection unit that detects a phase current of an AC motor and calculates at least one of an active power and a reactive power of the AC motor; a diagnosis unit that performs a diagnosis regarding deterioration or abnormality of the AC motor based on the frequency component of at least one of the active power and the reactive power. picture, The diagnosing unit performs the diagnosis on at least one of the active power and the reactive power based on a frequency component obtained by a frequency analysis and an amplitude of vibration obtained by a waveform counting method. A diagnostic device is provided.

[0008] In still another embodiment of the present disclosure, a calculation step in which a diagnostic device acquires an output of a current detection unit that detects a phase current of an AC motor, and calculates at least one of an active power and a reactive power of the AC motor based on the output of the current detection unit; A diagnosis step in which the diagnosis device performs a diagnosis regarding deterioration or abnormality of the AC motor based on the frequency component of at least one of the active power and the reactive power. fruit , In the diagnosis step, the diagnosis is performed on at least one of the active power and the reactive power based on a frequency component obtained by a frequency analysis and an amplitude of vibration obtained by a waveform counting method. A diagnostic method is provided. Effect of the Invention

[0009] According to the above-described embodiment, it is possible to more appropriately perform diagnosis regarding deterioration or abnormality of an AC motor. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 illustrates an example of a configuration of a degradation and abnormality diagnosis system. [Diagram 2] FIG. 2 is a functional block diagram showing an example of a functional configuration of a power conversion device (control device). [Diagram 3] FIG. 2 is a functional block diagram showing an example of a calculation process of active power and reactive power by a power calculation unit. [Figure 4] FIG. 2 is a diagram showing the amplitude of the instantaneous active power and instantaneous reactive power of the motor in a normal state in a time series manner. [Diagram 5] 1 is a diagram showing a time series of the amplitude of the instantaneous active power and the instantaneous reactive power of a motor in a state where deterioration abnormality has progressed relatively. [Figure 6] 1 is a diagram illustrating an example of a result of a frequency analysis of instantaneous active power and instantaneous reactive power of a motor. [Figure 7] FIG. 2 illustrates an example of a configuration of an analysis unit. [Figure 8] FIG. 11 is a diagram illustrating an example of a method for diagnosing deterioration and abnormality based on the results of frequency analysis. [Figure 9] 4 is a flowchart illustrating an example of a process for diagnosing deterioration or abnormality of an electric motor. [Figure 10] FIG. 11 is a functional block diagram showing another example of the functional configuration of the power conversion device (control device). [Figure 11] 1 is a diagram illustrating an example of a result of an amplitude analysis of instantaneous active power and instantaneous reactive power of a motor. [Figure 12] FIG. 11 is a diagram showing an example of a method for diagnosing deterioration abnormality based on the results of amplitude analysis. [Figure 13] 13A and 13B are diagrams illustrating another example of a method for diagnosing deterioration abnormality based on the results of amplitude analysis. [Figure 14] 10 is a flowchart illustrating another example of the deterioration abnormality diagnosis process for the electric motor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment will be described with reference to the drawings.

[0012] [Outline of the deterioration abnormality diagnosis system] First, with reference to FIG. 1, an overview of a deterioration and abnormality diagnosis system 1 according to this embodiment will be described.

[0013] FIG. 1 is a diagram showing a first example of the configuration of a degradation and abnormality diagnosis system 1 according to this embodiment.

[0014] The deterioration / abnormality diagnosis system 1 diagnoses the deterioration / abnormality of the electric motor M.

[0015] The diagnosis regarding the deterioration abnormality of the motor M includes, for example, a diagnosis of the presence or absence of the deterioration abnormality of the motor M and a diagnosis (estimation) of the degree of progress of the deterioration abnormality of the motor M. The degree of progress of the deterioration abnormality of the motor M may be expressed, for example, in a plurality of stages (levels), or may be expressed by a continuously changing numerical value, etc.

[0016] Deterioration of the motor M includes, for example, insulation deterioration of the windings (coils). Insulation deterioration refers to deterioration that occurs in the insulation of the windings of the motor M due to at least one of thermal, electrical, mechanical, and environmental factors. When insulation deterioration progresses, for example, the resistance value of the windings in the part where insulation deterioration has progressed changes, causing an imbalance in the windings and disrupting the current balance. Eventually, a phase short circuit occurs in the windings, leading to a mechanical failure of the motor M.

[0017] In response to this, the degradation anomaly diagnosis system 1 performs a diagnosis regarding degradation anomalies including insulation deterioration of the motor M, thereby enabling the user to grasp the presence or absence of degradation anomalies of the motor M and the degree of their progress. As a result, for example, the user can grasp in advance signs of mechanical failure of the motor M. Thus, the degradation anomaly diagnosis system 1 can reduce the frequency of maintenance of the equipment including the motor M and perform maintenance in accordance with the condition of the motor M, while also reducing the risk of sudden shutdown of the equipment including the motor M and long-term shutdown of the equipment associated with the restoration work.

[0018] As shown in FIG. 1, the degradation and abnormality diagnostic system 1 includes a power conversion device 100, a sensor 200, a management device 300, and a terminal device 400.

[0019] The power conversion device 100, the management device 300, and the terminal device 400 included in the degradation and abnormality diagnostic system 1 may each be one or more.

[0020] The power conversion device 100 converts three-phase AC power (e.g., R phase, S phase, and T phase) input from a commercial power source PS into three-phase AC power (e.g., U phase, V phase, and W phase) having a predetermined voltage and a predetermined frequency, and drives an electric motor M.

[0021] The power conversion device 100 may generate three-phase AC power for driving the motor M based on three-phase AC power input from a power source other than the commercial power source PS. The power conversion device 100 may also generate three-phase AC power for driving the motor M based on power input from a DC power source instead of or in addition to the power input from the three-phase AC power source. In this case, the DC power is input to a DC link unit (positive line PL and negative line NL) between the rectifier circuit 110 and the inverter circuit 130.

[0022] A circuit breaker BK capable of switching between a connected state and a disconnected state of the AC transmission path is installed in the AC transmission path (R-phase, S-phase, and T-phase electric wires) between the commercial power source PS and the power conversion device 100. The circuit breaker BK is, for example, a molded case circuit breaker (MCCB).

[0023] The electric motor M (an example of an AC electric motor) electrically drives a specific machine or a specific facility installed in a factory or building based on the three-phase AC power output from the power conversion device 100. The specific machine includes, for example, a compressor, a fan, a blower, etc. In addition, the specific facility includes, for example, a conveying device such as an elevator or a belt conveyor.

[0024] As shown in FIG. 1, the power conversion device 100 includes a rectifier circuit 110, a smoothing circuit 120, an inverter circuit 130, a control device 140, a sensor 150, a display device 160, and a communication device 170.

[0025] The rectifier circuit 110 is configured to be capable of rectifying three-phase AC power of R phase, S phase, and T phase input from a commercial power source PS and outputting DC power. The rectifier circuit 110 has positive and negative output terminals connected to one end of a positive line PL and a negative line NL, respectively, and can output DC power to the smoothing circuit 120 through the positive line PL and the negative line NL. The rectifier circuit 110 is, for example, a bridge-type full-wave rectifier circuit including six semiconductor diodes, in which three sets of series-connected bodies of two semiconductor diodes constituting upper and lower arms are connected in parallel.

[0026] The smoothing circuit 120 suppresses and smoothes pulsations in the DC power output from the rectifier circuit 110 and the DC power regenerated from the inverter circuit 130 .

[0027] The smoothing circuit 120 includes, for example, a smoothing capacitor.

[0028] The smoothing capacitor may be provided in parallel with the rectifier circuit 110 and the inverter circuit 130 in a path connecting the positive line PL and the negative line NL.

[0029] The smoothing capacitor smoothes the DC power output from the rectifier circuit 110 and the DC power output (regenerated) from the inverter circuit 130 while repeatedly charging and discharging as appropriate.

[0030] There may be one smoothing capacitor. Alternatively, a plurality of smoothing capacitors may be disposed, and the plurality of smoothing capacitors may be connected in parallel or in series between the positive line PL and the negative line NL. Alternatively, the plurality of smoothing capacitors may be configured in such a way that a series connection of two or more smoothing capacitors is connected in parallel between the positive line PL and the negative line NL.

[0031] Moreover, the smoothing circuit 120 includes, for example, a reactor.

[0032] The reactor may be provided on the positive line PL between the rectifier circuit 110 and the smoothing capacitor (specifically, the branch point from the path where the smoothing capacitor is disposed).

[0033] The reactor smoothes the DC power output from the rectifier circuit 110 and the DC power output (regenerated) from the inverter circuit 130 while appropriately generating a voltage to prevent a change in the current.

[0034] The inverter circuit 130 (an example of a drive unit) has positive and negative input terminals connected to the other terminals of the positive line PL and the negative line NL. The inverter circuit 130 converts the DC power supplied from the smoothing circuit 120 into three-phase AC power (e.g., U phase, V phase, and W phase) having a predetermined frequency and a predetermined voltage by switching operations of a semiconductor switch, outputs the power to the motor M, and drives the motor M. The semiconductor switch may be, for example, an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) made of silicon (Si). The semiconductor switch may also be, for example, a semiconductor element using a wide band gap semiconductor such as silicon carbide (SiC) or gallium nitride (GaN).

[0035] The inverter circuit 130 includes, for example, six semiconductor switches, and is configured to include a bridge circuit in which three sets of series-connected bodies (switch legs) of two semiconductor switches constituting upper and lower arms are connected in parallel between a positive line PL and a negative line NL. The inverter circuit 130 may output three-phase AC power through a U-phase wire, a V-phase wire, and a W-phase wire drawn from the connection points of the three sets of upper and lower arms. A free wheel diode may be connected in parallel to each of the six semiconductor switches.

[0036] The control device 140 (an example of a diagnostic device) controls the power conversion device 100 .

[0037] The functions of the control device 140 may be realized by any hardware or a combination of any hardware and software. For example, the control device 140 is mainly configured with a computer including a CPU (Central Processing Unit), a memory device such as a RAM (Random Access Memory), a non-volatile auxiliary storage device such as a ROM (Read Only Memory), and an interface device for input and output with the outside. The control device 140 realizes various functions, for example, by loading a program installed in the auxiliary storage device into the memory device and having the CPU execute the program. In addition, the control device 140 receives external signals and outputs (transmits) signals to the outside through the interface device.

[0038] The control device 140 outputs a drive signal to the inverter circuit 130 (specifically, to the gates of the respective semiconductor switches), for example, and drives the electric motor M so as to satisfy predetermined operating conditions using the inverter circuit 130. In other words, the control device 140 generates a control signal for driving the electric motor M in accordance with the predetermined operating conditions, and outputs the control signal to the inverter circuit 130.

[0039] Furthermore, the control device 140 performs, for example, a diagnosis regarding deterioration or abnormality of the electric motor M. The details will be described later.

[0040] The functions of the control device 140 may be realized in a form distributed among a plurality of control devices (control circuits). For example, the function of driving the motor M via the inverter circuit 130 and the function of diagnosing the deterioration abnormality of the motor M may be realized by different control devices of the power conversion device 100. Also, some or all of the functions of the control device 140 may be transferred to an external device of the power conversion device 100, such as the management device 300 or the terminal device 400 (both are examples of a diagnostic device). For example, some or all of the diagnostic function for the deterioration abnormality of the motor M may be transferred to the management device 300, the terminal device 400, or the like.

[0041] The sensor 150 acquires detection data related to the state of the power conversion device 100. The sensor 150 is connected to the control device 140, for example, via a one-to-one communication line or the like, and a signal corresponding to the detection data (hereinafter, "detection signal") is taken into the control device 140. This allows the control device 140 to control the power conversion device 100 based on the detection signal of the sensor 150.

[0042] The sensor 150 includes, for example, a voltage sensor that detects a link voltage between the positive line PL and the negative line NL. The sensor 150 (an example of a current detection unit) also includes, for example, a current sensor that detects currents of the U-phase line, the V-phase line, and the W-phase line between the inverter circuit 130 and the motor M, i.e., phase currents of the U-phase, the V-phase, and the W-phase of the motor M (hereinafter, respectively, referred to as "U-phase current", "V-phase current", and "W-phase current"). The current sensor detects the phase current of the motor M using, for example, a Hall sensor, a shunt resistor, a fluxgate, or the like, and outputs a detection value (digital value) of the phase current using an AD (Analog-Digital) converter. The sensor 150 may also include a voltage sensor that detects the phase voltages of the circuits between the inverter circuit 130 and the motor M, i.e., the U-phase line, the V-phase line, and the W-phase line (hereinafter, respectively, referred to as "U-phase voltage", "V-phase voltage", and "W-phase voltage").

[0043] The display device 160 is provided, for example, on the outer surface of a housing of the power conversion device 100. The display device 160 displays information related to the power conversion device 100 under the control of the control device 140.

[0044] The display device 160 may be provided outside the housing of the power conversion device 100, for example, on the surface (outer surface) of a housing of a production facility, a mechanical facility, or the like electrically driven by the electric motor M.

[0045] The communication device 170 communicates with devices external to the power electronics device 100, such as the management device 300 and the terminal device 400, through a predetermined communication line.

[0046] The predetermined communication line may be, for example, a one-to-one communication line. The predetermined communication line may include, for example, a local network (LAN) such as a field network constructed in a facility (factory) where production equipment, machinery, etc. electrically driven by the electric motor M are installed. The local network may be constructed as a wired network, may be constructed as a wireless network, or may include both. The predetermined communication line may include, for example, a wide area network (WAN) outside the facility (factory) where production equipment, machinery, etc. electrically driven by the electric motor M are installed. The wide area network may include, for example, a mobile communication network with a base station as an end, a satellite communication network using a communication satellite, an Internet network, etc. The predetermined communication line may also include, for example, a short-distance communication line according to a predetermined wireless communication standard such as Bluetooth (registered trademark) or WiFi.

[0047] The function of the communication device 170 may be built into the control device 140 as an interface with an external device.

[0048] The sensor 200 is provided outside the power conversion device 100 and outputs detection data related to the state of the electric motor M. The sensor 200 is, for example, a rotational position sensor capable of detecting the state of the rotational position and rotational speed of the electric motor M. The rotational position sensor may be, for example, an encoder. The encoder may detect the rotational position and rotational speed of the electric motor M by any method, such as an optical method or a magnetic method. The output (detection data) of the sensor 200 is taken into the power conversion device 100 (control device 140) via a one-to-one communication line or the like.

[0049] The detection data of the sensor 200 may be input to the control device 140 via the communication device 170 instead of being input directly to the control device 140 via a predetermined communication line.

[0050] The management device 300 is provided outside the power conversion device 100, and manages (monitors) the power conversion device 100 and the electric motor M as a higher-level device of the power conversion device 100. The management device 300, for example, acquires data relating to the states of the power conversion device 100 and the electric motor M from the power conversion device 100, and monitors the states of the power conversion device 100 and the electric motor M. The management device 300 also outputs, for example, a control signal to the power conversion device 100, and controls the power conversion device 100 and the electric motor M. The management device 300 also provides information relating to the power conversion device 100 and the electric motor M to a user, such as an operator or a manager, via a display unit 310, and receives input from the user and transmits the information to the power conversion device 100.

[0051] The management device 300 is, for example, an edge controller such as a PLC (Programmable Logic Controller) that manages a field device including the power conversion device 100 in a factory or the like where a specific machine or equipment including the electric motor M is installed. The management device 300 is, for example, a management terminal device. The management terminal device may be, for example, a stationary computer terminal such as a desktop PC (Personal Computer) installed in an office of a factory or the like. The management terminal device may be, for example, a portable terminal device (mobile terminal) that can be carried by a manager or worker of a factory or the like, such as a tablet terminal, a smartphone, or a laptop PC. The management device 300 is, for example, a server device. The server device may be, for example, an on-premise server or a cloud server that is installed remotely in a factory or the like where a specific machine or equipment including the electric motor M is installed. The server device may be, for example, an edge server that is installed on the premises of a factory or the like where a specific machine or equipment including the electric motor M is installed, or in a facility nearby the factory.

[0052] The terminal device 400 is a user terminal provided outside the power conversion device 100 and used by a user of the power conversion device 100 (deterioration anomaly diagnosis system 1). The terminal device 400 provides the user with various information related to the power conversion device 100 and the electric motor M through a display unit 410, for example, and receives various inputs from the user and transmits them to the power conversion device 100.

[0053] The terminal device 400 may be, for example, a stationary terminal device such as a desktop PC, etc. The terminal device 400 may also be, for example, a portable terminal device (mobile terminal) such as a smartphone, a tablet terminal, or a laptop PC.

[0054] [An example of the functional configuration of a power conversion device] Next, an example of a functional configuration of the power conversion device 100 will be described with reference to FIGS.

[0055] Fig. 2 is a functional block diagram showing an example of a functional configuration of the power conversion device 100 (control device 140) according to this embodiment. Fig. 3 is a functional block diagram showing an example of a calculation process of the instantaneous active power P and the instantaneous reactive power Q by the power calculation unit 1402.

[0056] 2, the control device 140 includes an electric motor control unit 1401, a power calculation unit 1402, an analysis unit 1403, a feature acquisition unit 1404, a diagnosis unit 1405, and a notification unit 1406. Some or all of the functions of the electric motor control unit 1401, the power calculation unit 1402, the analysis unit 1403, the feature acquisition unit 1404, the diagnosis unit 1405, and the notification unit 1406 are realized, for example, by a program installed in an auxiliary storage device being loaded into a memory device and executed by a CPU.

[0057] The motor control unit 1401 controls the drive of the motor M using the inverter circuit 130. The motor control unit 1401 may control the drive of the motor M using any control method such as V / f control or vector control.

[0058] Specifically, the motor control unit 1401 generates a control signal (drive command) for driving the motor M under specified operating conditions based on detection data from the sensor 150 (e.g., detection values ​​of U-phase current, V-phase current, and W-phase current), and outputs the control signal to the inverter circuit 130.

[0059] For example, the motor control unit 1401 generates command values ​​(hereinafter, “voltage command values”) for U-phase voltage, V-phase voltage, and W-phase voltage based on the detection data of the sensor 150 and the operating conditions of the motor M, and outputs a control signal corresponding to the voltage command value to the inverter circuit 130.

[0060] The power calculation unit 1402 (an example of a calculation unit) calculates the instantaneous active power P and the instantaneous reactive power Q of the electric motor M based on the detection data of the sensor 150.

[0061] For example, as shown in FIG. 3, when the motor control unit 1401 employs vector control, the instantaneous active power P and instantaneous reactive power Q of the motor M are calculated using the calculation results in the process related to the vector control.

[0062] In this case, the electric motor control unit 1401 includes a three-phase to two-phase conversion unit 1401A, a rotational coordinate conversion unit 1401B, a speed adjustment unit 1401C, a current command generation unit 1401D, a current adjustment unit 1401E, a conversion unit 1401F, and a drive command output unit 1401G.

[0063] The three-phase to two-phase conversion unit 1401A converts the U-phase current Iu, V-phase current Iv, and W-phase current Iw detected by the sensor 150 (current sensor) into an α-axis current Iα and a β-axis current Iβ in a two-phase fixed coordinate system (α-axis, β-axis) by a known method such as Clarke transformation.

[0064] In addition, the U-phase current Iu, the V-phase current Iv, and the W-phase current Iw may all be detected by sensor 150 (current sensor), or only the currents of any two phases may be detected by sensor 150, and the current of the remaining phase may be estimated based on the other two detected values.

[0065] The rotating coordinate conversion unit 1401B converts the α-axis current Iα and β-axis current Iβ based on the output of the sensor 150 into the d-axis current Id and q-axis current Iq of a two-phase rotating coordinate system (d-axis, q-axis) on the motor M by a known method such as the Park conversion.

[0066] The speed adjustment unit 1401C adjusts the rotation speed of the motor M based on a command value (hereinafter, "speed command") ω* of the angular velocity of the motor M based on the operating conditions of the motor M and the angular velocity ω of the motor M detected by the sensor 200 (rotational position sensor). For example, the speed adjustment unit 1401C generates and outputs a command value (hereinafter, "torque command") τ* of the torque of the motor M for bringing the deviation between the actual angular velocity ω of the motor and the speed command ω* closer to zero. The speed adjustment unit 1401C may generate the torque command τ* by any control method. For example, the speed adjustment unit 1401C generates the torque command τ* by using P (Proportional) control, PI (Proportional-Integral) control, PID (Proportional-Integral-Differential) control, or the like.

[0067] Incidentally, the angular velocity ω may be estimated based on the phase current and the phase voltage of the motor M, without depending on the output of the sensor 200 (rotational position sensor). In this case, the sensor 200 (rotational position sensor) is omitted.

[0068] The current command generating unit 1401D generates and outputs a d-axis current command value (hereinafter, “d-axis current command”) Id* and a q-axis current command value (hereinafter, “q-axis current command”) Iq* of the motor M to realize the torque command τ* based on the torque command τ*.

[0069] The current adjustment unit 1401E adjusts the current of the motor M based on the d-axis current command Id* and the q-axis current command Iq*, and the d-axis current Id and the q-axis current Iq corresponding to the actual detection value of the motor M. For example, the current adjustment unit 1401E generates and outputs a d-axis voltage command value (hereinafter, "d-axis voltage command") Vd* and a q-axis voltage command value (hereinafter, "q-axis voltage command") Vq* of the motor M for bringing the deviation between the d-axis current command Id* and the d-axis current Id, and the deviation between the q-axis current command Iq* and the q-axis current Iq close to zero. The current adjustment unit 1401E may generate the d-axis voltage command Vd* and the q-axis voltage command Vq* by any control method. For example, the speed adjustment unit 1401C generates the d-axis voltage command Vd* and the q-axis voltage command Vq* by using P control, PI control, PID control, or the like.

[0070] The conversion unit 1401F converts the d-axis voltage command Vd* and the q-axis voltage command Vq* into a command value for a U-phase voltage (hereinafter, the "U-phase voltage command") Vu*, a command value for a V-phase voltage (hereinafter, the "V-phase voltage command") Vv*, and a command value for a W-phase voltage (hereinafter, the "W-phase voltage command") Vw*.

[0071] The drive command output unit 1401G generates a drive command for the inverter circuit 130 based on the U-phase voltage command Vu*, V-phase voltage command Vv*, and W-phase voltage command Vw* of the motor M, and outputs the drive command to the inverter circuit 130. Specifically, the drive command output unit 1401G generates a gate drive command for the semiconductor switch of the inverter circuit 130, and applies the gate terminal of the semiconductor switch of the inverter circuit 130. This allows the motor control unit 1401 to appropriately drive and control the motor M using the inverter circuit 130 so as to comply with predetermined operating conditions.

[0072] The power calculation unit 1402 may calculate the instantaneous active power P and instantaneous reactive power Q of the motor M based on the output (d-axis current Id, q-axis current Iq) of the rotational coordinate transformation unit 1401B and the output (d-axis voltage command Vd*, q-axis voltage command Vq*) of the current adjustment unit 1401E using the following equations (1) and (2).

[0073]

number

[0074] When V / f control or the like is adopted, the U-phase voltage command Vu*, V-phase voltage command Vv*, and W-phase voltage command Vw* generated by the motor control unit 1401 may be coordinate-converted in accordance with the rotation of the motor M to generate a d-axis voltage command Vd* and a q-axis voltage command Vq*. The power calculation unit 1402 may calculate the instantaneous active power P and instantaneous reactive power Q of the motor M using the current and voltage in a fixed coordinate system (α-axis, β-axis) instead of the current and voltage in the rotating coordinate system (d-axis, q-axis).

[0075] The analysis unit 1403 performs an analysis regarding changes in the instantaneous active power P and the instantaneous reactive power Q, which indicate the progress of the deterioration abnormality of the motor M. Details will be described later (see FIG. 6).

[0076] A feature amount acquiring unit 1404 (an example of an acquiring unit) acquires a feature amount related to deterioration abnormality of the electric motor M based on the analysis result of the analyzing unit 1403. Details will be described later (see FIG. 8).

[0077] The diagnosing unit 1405 performs diagnosis regarding deterioration or abnormality of the electric motor M based on the feature amount acquired by the feature amount acquiring unit 1404. Details will be described later (see FIG. 8).

[0078] The notification unit 1406 notifies the user of the diagnosis result by the diagnosis unit 1405. The notification unit 1406 may, for example, display information related to the diagnosis result on the display device 160. The notification unit 1406 may also transmit a signal including information related to the diagnosis result to the management device 300 or the terminal device 400 via the communication device 170. This allows the notification unit 1406 to display information related to the diagnosis result on the display unit 310 of the management device 300 or the display unit 410 of the terminal device 400, and notify the user of the diagnosis result.

[0079] The management device 300 may, for example, aggregate diagnostic results related to deterioration abnormalities of the multiple electric motors M that are managed, and notify the user through the display unit 310. The management device 300 may also create a maintenance plan based on the diagnostic results related to deterioration abnormalities of the multiple electric motors M that are managed. The same may be true for the terminal device 400.

[0080] [An example of a diagnostic method for motor deterioration abnormalities] Next, an example of a method for diagnosing deterioration or abnormality of the electric motor M will be described with reference to Figs.

[0081] FIG. 4 is a diagram showing the amplitudes of the instantaneous active power P and the instantaneous reactive power Q of the motor M in a normal state in a time series. Specifically, FIG. 4 includes a graph 401 of the instantaneous active power P of the motor M in a normal state, and a graph 402 of the instantaneous reactive power Q in a time series. FIG. 5 is a diagram showing the amplitudes of the instantaneous active power P and the instantaneous reactive power Q of the motor M in a state in which the deterioration abnormality is relatively advanced in a time series. Specifically, FIG. 5 includes a graph 501 of the instantaneous active power P of the motor M in a state in which the deterioration abnormality is relatively advanced in a time series, and a graph 502 of the instantaneous reactive power Q in a time series. FIG. 6 is a diagram showing an example of the result of frequency analysis of the instantaneous active power P and the instantaneous reactive power Q of the motor M. FIG. 7 is a diagram showing an example of the configuration of the analysis unit 1403. FIG. 8 is a diagram showing an example of a method for diagnosing a deterioration abnormality based on the result of frequency analysis.

[0082] As shown in FIG. 4, when the motor M is in a normal state in which no deterioration abnormality has progressed, the amplitudes of the instantaneous active power P and the instantaneous reactive power Q of the motor M are approximately constant.

[0083] On the other hand, as shown in Fig. 5, when the motor M is in a state where the deterioration abnormality has progressed to a certain extent, an oscillatory component may occur in the amplitude of the instantaneous active power P and the instantaneous reactive power Q of the motor M. This is because when the motor M is deteriorated abnormally, frequency components (typically harmonic components) higher than the fundamental frequency may be superimposed on the waveforms of the instantaneous active power P and the instantaneous reactive power Q.

[0084] Therefore, in this example, the control device 140 focuses on the frequency components of the instantaneous active power P and the instantaneous reactive power Q to perform a diagnosis regarding deterioration or abnormality of the electric motor M.

[0085] Specifically, the analysis unit 1403 performs an analysis on the frequency components of the instantaneous active power P and the instantaneous reactive power Q (hereinafter, for convenience, referred to as "frequency analysis").

[0086] For example, as shown in FIG. 6, the analysis unit 1403 may perform a spectrum analysis of the instantaneous active power P and the instantaneous reactive power Q using FFT (Fast Fourier Transform) or the like.

[0087] In this example (Figure 6), very large spectral values ​​appear at certain frequency components (areas enclosed by dashed lines in the figure) that are higher than the fundamental frequency, which correspond to the vibration components of the amplitudes of the instantaneous active power P and the instantaneous reactive power Q.

[0088] Furthermore, for example, when the frequency of an oscillation component occurring in the amplitude of the instantaneous active power P and the instantaneous reactive power Q is known in advance, the analysis unit 1403 may include a narrow-band band-pass filter corresponding to a frequency band including that frequency. Then, the analysis unit 1403 may extract a predetermined frequency component from the instantaneous active power P and the instantaneous reactive power Q using the narrow-band band-pass filter.

[0089] The predetermined frequency component is, for example, a harmonic component, that is, a frequency component that is an integer multiple of the fundamental frequency. Also, the predetermined frequency component may be multiple.

[0090] 7, for example, in the case where the frequency of the vibration component occurring in the amplitude of the instantaneous active power P and the instantaneous reactive power Q varies depending on the rotation speed (angular speed ω) of the motor M, a tracking filter TF may be included. Then, the analysis unit 1403 may extract a predetermined frequency component related to the rotation frequency of the motor M from the instantaneous active power P and the instantaneous reactive power Q using the tracking filter TF.

[0091] Specifically, the tracking filter TF can extract the rotational frequency components of the motor M from the instantaneous active power P and the instantaneous reactive power Q by using the rotating coordinate transformation unit TF1 and the low-pass filter unit TF2. This is because the instantaneous active power P and the instantaneous reactive power Q correspond to DC components on a coordinate system rotating at the angular speed ω of the motor M. The tracking filter TF can then output predetermined frequency components related to the rotational frequencies in the instantaneous active power P and the instantaneous reactive power Q by using the fixed coordinate transformation unit TF3.

[0092] The feature amount acquiring unit 1404 acquires a feature amount (hereinafter, for convenience, a “frequency feature amount”) focusing on the frequency components of the instantaneous active power P and the instantaneous reactive power Q from the result of the frequency analysis by the analyzing unit 1403.

[0093] For example, the feature amount acquiring unit 1404 may acquire, as the frequency feature amount, the magnitude (e.g., spectrum value) of a predetermined frequency component of the instantaneous active power P and the instantaneous reactive power Q. This is because it is considered that the larger the magnitude of the predetermined frequency component is relatively, the more prominent the vibration component of the amplitude of the instantaneous active power P and the instantaneous reactive power Q becomes, and the more the deterioration abnormality progresses relatively.

[0094] The diagnosing unit 1405 diagnoses the deterioration or abnormality of the electric motor M based on the frequency feature amount.

[0095] For example, as shown in FIG. 8, when the magnitude (spectral value) of a certain frequency component of the instantaneous active power P or the instantaneous reactive power Q as a frequency feature exceeds a certain criterion (threshold value Sp_th), the diagnosis unit 1405 diagnoses that there is a possibility of deterioration or abnormality in the motor M.

[0096] The predetermined criterion (threshold Sp_th) may be a fixed value or may be a variable value that is changed depending on, for example, the operating state of the motor M. Furthermore, the predetermined criterion (threshold Sp_th) may be the same or different between the instantaneous active power P and the instantaneous reactive power Q.

[0097] Also, for example, in a case where there are a plurality of predetermined frequency components, if the sum of the magnitudes of the plurality of predetermined frequency components exceeds a predetermined threshold, it may be diagnosed that there is a possibility of deterioration or abnormality in the motor M.

[0098] Furthermore, for example, the diagnosis unit 1405 may diagnose the degree of progression of the deterioration abnormality of the motor M based on the magnitude of a predetermined frequency component. Specifically, the diagnosis unit 1405 diagnoses the degree of progression of the deterioration abnormality of the motor M such that the greater the magnitude of the predetermined frequency component, the greater (higher) the degree of progression of the deterioration abnormality of the motor M. The criterion for determining the degree of progression of the deterioration abnormality of the motor M may be fixed or may be variable depending on, for example, the operating state of the motor M.

[0099] In this manner, in this example, the control device 140 performs a diagnosis regarding deterioration or abnormality of the electric motor M based on the frequency components of the instantaneous active power P and the instantaneous reactive power Q.

[0100] This allows the control device 140 to notify the user of the possibility of deterioration abnormality leading to a mechanical failure of the electric motor M before the electric motor M breaks down and causes a sudden stop or the like of the equipment including the electric motor M. Therefore, the control device 140 can reduce the frequency of maintenance of the equipment including the electric motor M and perform maintenance according to the condition of the electric motor M, and can reduce the risk of a sudden stop of the equipment including the electric motor M and a long-term stop of the equipment due to the recovery work thereof.

[0101] Also, for example, it is possible to focus on the magnitudes of the instantaneous active power P and the instantaneous reactive power Q, but there is a possibility that an erroneous diagnosis will be made that there is a possibility of deterioration abnormality in the motor M by capturing an instantaneous change in magnitude. In this case, there is also a possibility that it will not be possible to diagnose deterioration abnormality of the motor M that is not reflected in the magnitudes of the instantaneous active power P and the instantaneous reactive power Q of the motor M.

[0102] In contrast, in this example, the control device 140 focuses on the frequency components of the instantaneous active power P and the instantaneous reactive power Q, thereby making it possible to more appropriately diagnose the deterioration or abnormality of the electric motor M.

[0103] In addition, for example, while it is conceivable to install a dedicated sensor or the like for diagnosing deterioration or abnormality of the motor M, an increase in costs for realizing a function for diagnosing deterioration or abnormality of the motor M is unavoidable.

[0104] In contrast, in this example, the control device 140 can diagnose the deterioration or abnormality of the motor M by using only the outputs of the sensors 150 and 200 required for controlling the motor M. Therefore, the control device 140 can diagnose the deterioration or abnormality of the motor M while suppressing an increase in costs.

[0105] The control device 140 may use only one of the instantaneous active power P and the instantaneous reactive power Q to perform a diagnosis of deterioration or abnormality of the electric motor M based on the frequency component.

[0106] [An example of deterioration abnormality diagnosis processing] Next, an example of a deterioration / abnormality diagnosis process for the electric motor M performed by the control device 140 will be described with reference to FIG.

[0107] FIG. 9 is a flowchart illustrating an example of a deterioration abnormality diagnosis process for the electric motor M.

[0108] This flowchart is executed at a predetermined timing. The predetermined timing is, for example, the timing of power-on of the power conversion device 100. As a result, the control device 140 can diagnose the deterioration abnormality of the electric motor M in accordance with the power-on of the power conversion device 100. The predetermined timing may be, for example, the timing at which a diagnosis request is input from a user through an input unit provided in the power conversion device 100. The predetermined timing may be, for example, the timing at which a diagnosis request is input from a user from the management device 300 or the terminal device 400 through the communication device 170. The same may be true for the flowchart of FIG. 14 described below. The predetermined timing may be, for example, when the electric motor M is in operation (operating). Specifically, the predetermined timing may be a timing synchronized with the timing (control period) of the control of the electric motor M by the electric motor control unit 1401.

[0109] 9, in step S102, the power calculation unit 1402 acquires the latest data for calculating the latest instantaneous active power P and the latest instantaneous reactive power Q. The latest data is, for example, the latest d-axis current Id, q-axis current Iq, d-axis voltage command Vd*, and q-axis voltage command Vq*.

[0110] When the process of step S102 is completed, the control device 140 proceeds to step S104.

[0111] In step S104, the power calculation unit 1402 calculates the instantaneous active power P and the instantaneous reactive power Q based on the data acquired in step S102.

[0112] When the process of step S104 is completed, the control device 140 proceeds to step S106.

[0113] In step S106, the analysis unit 1403 performs a frequency analysis on the instantaneous active power P and the instantaneous reactive power Q calculated in step S104.

[0114] When the process of step S106 is completed, the control device 140 proceeds to step S108.

[0115] In step S108, the feature amount acquiring unit 1404 acquires a feature amount (frequency feature amount) related to the deterioration abnormality of the electric motor M based on the result of the frequency analysis in step S106.

[0116] When the process of step S108 is completed, the control device 140 proceeds to step S110.

[0117] In step S110, the diagnosing unit 1405 performs diagnosis regarding deterioration or abnormality of the electric motor M based on the feature amount (frequency feature amount) acquired in step S108.

[0118] When the process of step S110 is completed, the diagnosis unit 1405 proceeds to step S112.

[0119] In step S112, the diagnosis unit 1405 determines whether or not there is a possibility of deterioration abnormality of the motor M. If there is a possibility of deterioration abnormality of the motor M, the diagnosis unit 1405 proceeds to step S114, and if there is no possibility of deterioration abnormality of the motor M, the diagnosis unit 1405 proceeds to step S116.

[0120] In addition, when the diagnosing unit 1405 diagnoses the degree of progress of the deterioration abnormality of the motor M, in step S112, it may be determined whether or not the degree of progress exceeds a predetermined standard. The predetermined standard is, for example, determined in advance as a lower limit of the degree of progress of the deterioration abnormality of the motor M at which maintenance of the motor M is considered to be performed through experiments, computer simulations, etc. In this case, in step S114 described later, it may be notified that the degree of progress of the deterioration abnormality of the motor M exceeds the predetermined standard. In addition, when the diagnosing unit 1405 diagnoses the degree of progress of the deterioration abnormality of the motor M, a process of notifying the user of the degree of progress of the deterioration abnormality of the motor M as a diagnosis result may be performed instead of step S112 and steps S114 and S116 described later. In addition, in the case where the deterioration abnormality diagnosis process is performed regardless of a diagnosis request from a user, such as when it is performed when the power of the power conversion device 100 is turned on, the process of step S116 described later may be omitted.

[0121] In step S114, the notification unit 1406 notifies the user, via the display device 160 and the communication device 170, of the diagnosis result that the motor M may be deteriorated or abnormal.

[0122] The notification unit 1406 may also issue a notification urging the user to perform maintenance on the electric motor M.

[0123] When the process of step S114 is completed, the control device 140 ends the process of this flowchart.

[0124] On the other hand, in step S116, the notification unit 1406 notifies the user, via the display device 160 and the communication device 170, of the diagnosis result that the electric motor M is normal.

[0125] When the process of step S116 is completed, the control device 140 ends the process of this flowchart.

[0126] [Another example of the functional configuration of a power conversion device] Next, another example of the functional configuration of the power conversion device 100 will be described with reference to Fig. 10. The following description will focus on the parts that differ from the above example (Fig. 2).

[0127] FIG. 10 is a functional block diagram showing another example of the functional configuration of the power conversion device 100 (control device 140) according to this embodiment.

[0128] 10, like the above-described example, the control device 140 includes an electric motor control unit 1401, a power calculation unit 1402, an analysis unit 1403, a feature acquisition unit 1404, a diagnosis unit 1405, and a notification unit 1406. Some or all of the functions of the electric motor control unit 1401, the power calculation unit 1402, the analysis unit 1403, the feature acquisition unit 1404, the diagnosis unit 1405, and the notification unit 1406 are realized, for example, by a program installed in an auxiliary storage device being loaded into a memory device and executed by a CPU.

[0129] Similar to the above-described example, the analysis unit 1403 performs an analysis on changes in the instantaneous active power P and the instantaneous reactive power Q, which indicate the progress of the deterioration abnormality of the motor M. Specifically, unlike the above-described example, the analysis unit 1403 includes a frequency analysis unit 1403A and an amplitude analysis unit 1403B.

[0130] The frequency analysis unit 1403A performs frequency analysis on the instantaneous active power P and the instantaneous reactive power Q, similarly to the case of the analysis unit 1403 in the above-mentioned example.

[0131] The above-mentioned example of the analysis section 1403 corresponds to a configuration including only the frequency analysis section 1403A out of the frequency analysis section 1403A and the amplitude analysis section 1403B.

[0132] As described below, the amplitude analysis unit 1403B performs an analysis (hereinafter, for convenience, "amplitude analysis") on the amplitude of an oscillation component having a shorter wavelength than that of a fundamental wave (hereinafter, simply "amplitude of oscillation component") that occurs in the instantaneous active power P and the instantaneous reactive power Q. Details will be described later (see FIG. 11).

[0133] Similar to the above-described example, the feature amount acquiring unit 1404 acquires feature amounts related to deterioration abnormality of the motor M based on the analysis result of the analysis unit 1403. Specifically, unlike the above-described example, the feature amount acquiring unit 1404 includes feature amount acquiring units 1404A and 1404B.

[0134] Similar to the above-described example of the feature amount acquiring unit 1404, the feature amount acquiring unit 1404A acquires a frequency feature amount based on the result of the frequency analysis by the analysis unit 1403 (frequency analysis unit 1403A).

[0135] The analysis unit 1403 in the above example corresponds to a configuration including only the feature amount acquisition unit 1404A out of the feature amount acquisition units 1404A and 1404B.

[0136] Based on the result of the amplitude analysis by the amplitude analysis unit 1403B, the feature acquisition unit 1404B acquires a feature (hereinafter, for convenience, an "amplitude feature") focusing on the amplitude of the vibration components of the instantaneous active power P and the instantaneous reactive power Q. Details will be described later (see Figs. 12 and 13).

[0137] As in the above example, the diagnosing unit 1405 performs diagnosis regarding deterioration or abnormality of the electric motor M based on the frequency feature amount acquired by the feature amount acquiring unit 1404 (feature amount acquiring unit 1404A).

[0138] Further, similarly to the above-described example, the diagnosing unit 1405 performs diagnosis regarding deterioration or abnormality of the motor M based on the amplitude feature acquired by the feature acquiring unit 1404 (feature acquiring unit 1404B). Details will be described later (see Figs. 12 and 13).

[0139] [Another example of a diagnosis method for deterioration abnormalities in electric motors] Next, another example of the diagnosis method for deterioration or abnormality of the electric motor M will be described with reference to Figs. 11 to 13 in addition to Figs. 4 and 5 described above.

[0140] Fig. 11 is a diagram showing an example of the result of amplitude analysis of instantaneous active power P and instantaneous reactive power Q of a motor M. Fig. 12 is a diagram showing an example of a method for diagnosing deterioration abnormality based on the result of amplitude analysis. Fig. 13 is a diagram showing another example of a method for diagnosing deterioration abnormality based on the result of amplitude analysis.

[0141] 4 and 5, as described above, when the motor M is in a state where the deterioration abnormality has progressed to a certain extent, an oscillatory component may occur in the amplitude of the instantaneous active power P and the instantaneous reactive power Q of the motor M. As the deterioration abnormality of the motor M progresses, the oscillatory component becomes more prominent.

[0142] Therefore, in this example, the control device 140 performs diagnosis of deterioration or abnormality of the motor M by focusing on the amplitude of vibration components that occur in the instantaneous active power P and instantaneous reactive power Q of the motor M and have a shorter wavelength than the fundamental wave.

[0143] Specifically, the amplitude analysis unit 1403B performs vibration analysis of the instantaneous active power P and the instantaneous reactive power Q as described above.

[0144] For example, as shown in Fig. 11, the amplitude analysis unit 1403B acquires the peak values ​​of the amplitude of the instantaneous active power P and the instantaneous reactive power Q by a waveform counting method. The peak value corresponds to the difference between the target amplitude peak and the previous amplitude peak. Then, the amplitude analysis unit 1403B may divide the acquired peak values ​​into predetermined ranges and acquire the number of times the peak values ​​have been measured for each predetermined range. In this case, any known method such as the local maximum / minimum method, the maximum / minimum method, the amplitude method, the level crossing method, the range bear method, the rainflow method, etc. may be applied.

[0145] 5, the amplitude analysis unit 1403B may acquire time-series waveform data corresponding to vibration components occurring in the amplitude of the instantaneous active power P and the instantaneous reactive power Q.

[0146] As described above, the feature amount acquiring unit 1404B acquires feature amounts (amplitude feature amounts) focusing on the amplitudes of the vibration components of the instantaneous active power P and the instantaneous reactive power Q from the analysis results of the amplitude analyzing unit 1403B.

[0147] For example, the feature acquisition unit 1404B acquires, as the amplitude feature, the number of measurements of peak values ​​exceeding a predetermined standard (threshold Pk_th) among the peak values ​​acquired by the amplitude analysis unit 1403B, or the ratio to the total number of measurements (hereinafter, "measurement rate"). This is because the peak values ​​of the amplitudes of the instantaneous active power P and the instantaneous reactive power Q correspond to the amplitudes of the vibration components, and the larger the peak value, the more deteriorated and abnormal the deterioration of the motor M is considered to be.

[0148] The predetermined criterion (threshold Pk_th) may be a fixed value or may be a variable value that is changed based on, for example, the operating state of the motor M. Furthermore, the predetermined criterion (threshold Pk_th) may be the same or different between the instantaneous active power P and the instantaneous reactive power Q.

[0149] Also, for example, the feature amount acquiring unit 1404B may acquire the amplitude value of the vibration component as the amplitude feature amount from the time-series waveform data of the vibration component of the amplitude of the instantaneous active power P or the instantaneous reactive power Q acquired by the amplitude analyzing unit 1403B. This is because it is considered that the larger the amplitude value of the vibration component is, the more the deterioration abnormality is relatively advanced.

[0150] As described above, the diagnosing unit 1405 performs diagnosis regarding deterioration or abnormality of the electric motor M based on the amplitude feature amount.

[0151] For example, as shown in FIG. 12, when the number of measurements or the measurement rate of a peak value (part enclosed by dashed line in the figure) exceeding a threshold value Pk_th as an amplitude feature exceeds a predetermined standard (threshold value N_th), the diagnosis unit 1405 diagnoses that there is a possibility of deterioration or abnormality in the motor M.

[0152] The predetermined criterion (threshold N_th) may be a fixed value or may be a variable value that is changed depending on, for example, the operating state of the motor M. Furthermore, the predetermined criterion (threshold N_th) may be the same for the instantaneous active power P and the instantaneous reactive power Q, or may be different.

[0153] Furthermore, for example, the diagnosis unit 1405 may diagnose the degree of progression of the deterioration abnormality of the motor M based on the number of measurements or the measurement rate of peak values ​​exceeding the threshold Pk_th as an amplitude feature. Specifically, the diagnosis unit 1405 diagnoses the degree of progression of the deterioration abnormality of the motor M such that the greater the number of measurements or the measurement rate of peak values ​​exceeding the threshold Pk_th, the greater (higher) the degree of progression of the deterioration abnormality of the motor M. The criterion for determining the degree of progression of the deterioration abnormality of the motor M may be fixed or may be variable depending on, for example, the operating state of the motor M.

[0154] Also, for example, as shown in FIG. 13, when the amplitude value of the vibration component as the amplitude feature exceeds a predetermined standard (threshold A_th), the diagnosing unit 1405 diagnoses that there is a possibility of deterioration or abnormality in the motor M.

[0155] The predetermined criterion (threshold A_th) may be a fixed value or may be a variable value that is changed depending on, for example, the operating state of the motor M. Furthermore, the predetermined criterion (threshold A_th) may be the same for the instantaneous active power P and the instantaneous reactive power Q, or may be different.

[0156] Also, for example, the diagnosing unit 1405 may diagnose the degree of progression of the deterioration abnormality of the motor M based on the amplitude value of the vibration component as the amplitude feature amount. Specifically, the diagnosing unit 1405 diagnoses the degree of progression of the deterioration abnormality of the motor M such that the greater the amplitude value of the vibration component of the amplitude of the instantaneous active power P or the instantaneous reactive power Q, the greater (higher) the degree of progression of the deterioration abnormality of the motor M. The criterion for determining the degree of progression of the deterioration abnormality of the motor M may be fixed as in the above case, or may be variable depending on, for example, the operating state of the motor M.

[0157] Thus, in this example, the control device 140 diagnoses deterioration or abnormality of the motor M based on the amplitude of the vibration components of the instantaneous active power P and the instantaneous reactive power Q, specifically, the vibration components having a wavelength shorter than that of the fundamental wave.

[0158] As a result, as in the example described above, the control device 140 can reduce the frequency of maintenance of the equipment including the electric motor M and perform maintenance according to the condition of the electric motor M, while also reducing the risk of sudden shutdowns of the equipment including the electric motor M and long-term shutdowns of the equipment due to recovery work.

[0159] In addition, by focusing on the amplitude of vibration components in the instantaneous active power P and the instantaneous reactive power Q that have a wavelength shorter than that of the fundamental wave, the control device 140 can more appropriately diagnose deterioration and abnormalities in the electric motor M, as in the example described above.

[0160] In this example, the control device 140 diagnoses the deterioration or abnormality of the motor M based on the frequency components of the instantaneous active power P and the instantaneous reactive power Q as well as the amplitude of the vibration component having a wavelength shorter than that of the fundamental wave.

[0161] This allows the control device 140 to perform diagnosis regarding deterioration abnormality of the electric motor M from two perspectives. Therefore, even if the control device 140 cannot detect a symptom of a malfunction of the electric motor M (possibility of deterioration abnormality) from one perspective, it may be possible to detect a symptom of a malfunction of the electric motor M from the other perspective. Therefore, the control device 140 can diagnose the possibility of deterioration abnormality of the electric motor M at an earlier stage.

[0162] The control device 140 may diagnose deterioration abnormality of the motor M based on the amplitude of the vibration component having a shorter wavelength than the fundamental wave by using only either the instantaneous active power P or the instantaneous reactive power Q. Furthermore, the control device 140 may only perform the latter diagnosis of the diagnosis of deterioration abnormality of the motor M based on the frequency components of the instantaneous active power P and the instantaneous reactive power Q and the diagnosis of deterioration abnormality of the motor M based on the amplitude of the vibration components of the instantaneous active power P and the instantaneous reactive power Q.

[0163] [Another example of deterioration abnormality diagnosis processing] Next, another example of the deterioration / abnormality diagnosis process for the electric motor M performed by the control device 140 will be described with reference to FIG.

[0164] FIG. 14 is a flowchart illustrating another example of the deterioration abnormality diagnosis process for the electric motor M.

[0165] As shown in FIG. 14, steps S202 and S204 are the same as the processes in steps S102 and S104 in FIG. 9, and therefore a description thereof will be omitted.

[0166] When the process of step S204 is completed, the control device 140 proceeds to step S206.

[0167] In step S206, the analysis unit 1403 (the frequency analysis unit 1403A and the amplitude analysis unit 1403B) performs frequency analysis and amplitude analysis on the instantaneous active power P and the instantaneous reactive power Q calculated in step S204.

[0168] When the process of step S206 is completed, the control device 140 proceeds to step S208.

[0169] In step S208, the feature acquisition unit 1404 (feature acquisition unit 1404A and feature acquisition unit 1404B) acquires feature amounts (frequency feature amount and amplitude feature amount) related to deterioration abnormality of the motor M based on the results of the frequency analysis and amplitude analysis in step S206.

[0170] When the process of step S208 is completed, the control device 140 proceeds to step S210.

[0171] In step S210, the diagnosing unit 1405 performs diagnosis regarding deterioration or abnormality of the electric motor M based on the feature amounts (frequency feature amount and amplitude feature amount) acquired in step S208.

[0172] Specifically, the diagnosing unit 1405 diagnoses the deterioration of the motor M based on the frequency feature amount, and also diagnoses the deterioration of the motor M based on the amplitude feature amount.

[0173] Furthermore, the diagnosis unit 1405 may perform a comprehensive diagnosis based on the individual diagnosis results based on the frequency feature amount and the individual diagnosis results based on the amplitude feature amount.

[0174] When the process of step S210 is completed, the control device 140 proceeds to step S212.

[0175] In step S212, the diagnosis unit 1405 determines whether or not there is a possibility of a deterioration abnormality in the motor M. For example, when either one of the individual diagnosis results based on the frequency feature amount and the individual diagnosis results based on the amplitude feature amount indicates that there is a possibility of a deterioration abnormality in the motor M, the diagnosis unit 1405 determines that there is a possibility of a deterioration abnormality in the motor M. Furthermore, the diagnosis unit 1405 may determine whether or not there is a possibility of a deterioration abnormality in the motor M as a comprehensive diagnosis result. When there is a possibility of a deterioration abnormality in the motor M, the diagnosis unit 1405 proceeds to step S214, and when there is no possibility of a deterioration abnormality in the motor M, the diagnosis unit 1405 proceeds to step S216.

[0176] In addition, when the degree of progress of the deterioration abnormality of the motor M is diagnosed by the diagnosing unit 1405, in step S212, it may be determined whether or not the degree of progress exceeds a predetermined criterion. The predetermined criterion may be the same as in the case of the above-mentioned example (FIG. 9). For example, when the degree of progress of the deterioration abnormality of the motor M exceeds a predetermined criterion in either one of the individual diagnosis results based on the frequency feature amount and the individual diagnosis results based on the amplitude feature amount, it is determined that the degree of progress of the deterioration abnormality of the motor M exceeds the predetermined criterion. In addition, as a comprehensive diagnosis result, it may be determined whether or not the degree of progress of the deterioration abnormality of the motor M exceeds a predetermined criterion. In this case, in step S214, it may be notified that the degree of progress of the deterioration abnormality of the motor M exceeds the predetermined criterion, as in the case of step S114 in FIG. 9. Furthermore, when the diagnosing unit 1405 diagnoses the degree of progress of the deterioration abnormality of the motor M, a process of notifying the user of the degree of progress of the deterioration abnormality of the motor M as a diagnosis result may be performed instead of steps S212 to S216. Furthermore, when the deterioration abnormality diagnosis process is performed regardless of a diagnosis request from the user, for example, when it is executed when the power conversion device 100 is powered on, the process of step S216 may be omitted.

[0177] Steps S214 and S216 are the same as steps S114 and S116 in FIG. 9, and therefore description thereof will be omitted.

[0178] When the processes of steps S214 and S216 are completed, the control device 140 ends the process of this flowchart.

[0179] Furthermore, the deterioration abnormality diagnosis process for the motor M based on the frequency components of the instantaneous active power P and the instantaneous reactive power Q, and the deterioration abnormality diagnosis process for the motor M based on the amplitude of the vibration components of the instantaneous active power P and the instantaneous reactive power Q may be performed as separate independent processes.

[0180] [Effect] Next, the operation of the deterioration and abnormality diagnostic system 1 according to this embodiment will be described.

[0181] In this embodiment, the power conversion device 100 includes an inverter circuit 130, a sensor 150, a power calculation unit 1402, and a diagnosis unit 1405. Specifically, the electric motor M is driven by using the inverter circuit 130 and power input from the outside. The sensor 150 detects a phase current of the electric motor M. The power calculation unit 1402 calculates at least one of active power and reactive power of the electric motor M based on the output of the sensor 150. The diagnosis unit 1405 performs diagnosis regarding deterioration or abnormality of the electric motor M based on the frequency components of at least one of the active power and reactive power of the electric motor M.

[0182] As a result, the power conversion device 100 can more appropriately diagnose deterioration abnormalities of the motor M compared to, for example, a case in which diagnosis of deterioration abnormalities of the motor M is performed by focusing on the magnitude of the active power and reactive power of the motor M.

[0183] In addition, in this embodiment, the diagnosing unit 1405 may diagnose deterioration or abnormality of the motor M based on a change in a predetermined frequency component of at least one of the active power and the reactive power of the motor M.

[0184] This allows the power conversion device 100 to detect, for example, a change in which a predetermined frequency component of the active power or reactive power of the motor M becomes relatively large, and diagnose the progression of deterioration or abnormality of the motor M.

[0185] In addition, in this embodiment, the power conversion device 100 may include a tracking filter TF. Specifically, the tracking filter TF may output a predetermined frequency component of at least one of the active power and the reactive power of the motor M, which changes according to the rotation speed of the motor M. Then, the diagnosing unit 1405 may perform a diagnosis regarding deterioration or abnormality of the motor M based on the output of the tracking filter TF.

[0186] As a result, the power conversion device 100 can appropriately diagnose deterioration abnormalities of the motor M even when certain frequency components of the active power and reactive power of the motor M, which indicate the progression of the deterioration abnormality of the motor M, change depending on the rotational speed of the motor M.

[0187] In addition, in this embodiment, the power conversion device 100 may include a feature amount acquiring unit 1404. Specifically, the feature amount acquiring unit 1404 may acquire a feature amount (frequency feature amount) related to a predetermined frequency component of at least one of the active power and the reactive power of the electric motor M. Then, the diagnosing unit 1405 may diagnose that there is a possibility of deterioration or abnormality in the electric motor M when the frequency feature amount exceeds a first predetermined standard (for example, a threshold value Sp_th).

[0188] Thus, the power conversion device 100 can specifically diagnose whether or not there is a possibility of deterioration or abnormality of the electric motor M by appropriately setting the first predetermined standard.

[0189] In the present embodiment, the first predetermined reference may be variable depending on the state of the electric motor M.

[0190] This allows the power conversion device 100 to appropriately diagnose the deterioration or abnormality of the electric motor M in accordance with the state of the electric motor M.

[0191] In addition, in this embodiment, the frequency feature may be the magnitude of a predetermined frequency component of at least one of the active power and reactive power of the motor M, or the sum of the magnitudes of multiple predetermined frequency components of at least one of the active power and reactive power of the motor M.

[0192] As a result, the power conversion device 100 can specifically detect changes in which a predetermined frequency component of the active power or reactive power of the motor M becomes relatively large, and diagnose whether or not there is a possibility of deterioration or abnormality of the motor M.

[0193] In addition, in this embodiment, the diagnosing unit 1405 may perform diagnosis regarding deterioration or abnormality of the motor M based on the frequency components of at least one of the active power and reactive power of the motor M and the amplitude of the vibration components.

[0194] This allows the power conversion device 100 to diagnose the deterioration or abnormality of the motor M from multiple perspectives. Therefore, the power conversion device 100 can diagnose a symptom of a failure of the motor M (possibility of deterioration or abnormality) at an earlier stage.

[0195] In addition, in this embodiment, the diagnosis unit 1405 may diagnose that there is a possibility of deterioration or abnormality in the motor M when the amplitude of at least one of the vibration components of the active power and reactive power of the motor M exceeds a second predetermined standard (e.g., threshold value A_th).

[0196] As a result, by appropriately setting the second predetermined standard, the power conversion device 100 can specifically detect changes in which the amplitudes of the vibration components of the active power and reactive power of the motor M become relatively larger, and diagnose whether or not there is a possibility of deterioration or abnormality in the motor M.

[0197] In addition, in this embodiment, the power electronics device 100 may include a notification unit 1406. Specifically, the notification unit 1406 may notify the user of the diagnosis result of the diagnosis unit 1405.

[0198] In this way, the power conversion device 100 can allow the user to recognize the state regarding the deterioration or abnormality of the electric motor M.

[0199] In addition, in this embodiment, the diagnostic function of the control device 140 regarding deterioration and abnormality of the electric motor M may be transferred to the management device 300 or the terminal device 400. Specifically, the management device 300 or the terminal device 400 may be configured to be able to acquire the output of the sensor 150 of the power conversion device 100 or a similar sensor, and may have a configuration similar to that of the power calculation unit 1402 and the diagnostic unit 1405, etc.

[0200] This allows the management device 300 and the terminal device 400 to more appropriately diagnose deterioration or abnormality of the electric motor M, similar to the above-mentioned power conversion device 100 and the like.

[0201] Although the embodiments have been described in detail above, the present disclosure is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist described in the claims. [Explanation of symbols]

[0202] 1. Deterioration and abnormality diagnosis system 100 Power conversion device 110 Rectifier circuit 120 Smoothing circuit 130 Inverter circuit (drive unit) 140 Control device (diagnostic device) 150 Sensor (current detection section) 160 Display device 170 Communication Equipment 200 Sensors 300 Management device (diagnostic device) 310 Display section 400 Terminal equipment (diagnostic equipment) 410 Display section 1401 Motor control unit 1402 Power calculation section (calculation section) 1403 Analysis Department 1403A Frequency Analysis Unit 1403B Amplitude analysis section 1404, 1404A, 1404B Feature acquisition unit (acquisition unit) 1405 Diagnostics Department 1406 Notification Department BK Circuit Breaker M Electric motor (AC motor) NL Negative Line PL positive line PS Commercial power supply (power supply)

Claims

1. A drive unit that drives an AC motor using power input from an external source; A current detection unit that detects a phase current of the AC motor; a calculation unit that calculates at least one of an active power and a reactive power of the AC motor based on an output of the current detection unit; a diagnosis unit that performs a diagnosis regarding deterioration or abnormality of the AC motor based on the frequency component of at least one of the active power and the reactive power, The diagnosing unit performs the diagnosis on at least one of the active power and the reactive power based on a frequency component obtained by a frequency analysis and an amplitude of vibration obtained by a waveform counting method. Power conversion equipment.

2. The diagnosing unit performs the diagnosis based on a change in a predetermined frequency component of the at least one of the active power and the reactive power. The power conversion device according to claim 1 .

3. a tracking filter that outputs the predetermined frequency component of the at least one of the active power and the reactive power, the tracking filter changing according to a rotation speed of the AC motor; The diagnosis unit performs the diagnosis based on an output of the tracking filter. The power conversion device according to claim 2 .

4. an acquisition unit that acquires a feature amount related to the predetermined frequency component of the at least one of the active power and the reactive power, the diagnosing unit performs the diagnosis that there is a possibility of deterioration or abnormality in the AC motor when the feature amount exceeds a first predetermined criterion. The power conversion device according to claim 2 or 3.

5. The first predetermined criterion is varied depending on a state of the AC motor. The power conversion device according to claim 4.

6. The feature amount is a magnitude of the predetermined frequency component of the at least one of the active power and the reactive power, or a sum of magnitudes of a plurality of the predetermined frequency components of the at least one of the active power and the reactive power. The power conversion device according to claim 4 or 5.

7. the diagnosing unit performs the diagnosis that there is a possibility of deterioration or abnormality in the AC motor when an amplitude of the vibration of at least one of the active power and the reactive power exceeds a second predetermined standard. The power conversion device according to any one of claims 1 to 6.

8. a notification unit that notifies a user of a diagnosis result of the diagnosis unit; A power conversion device according to any one of claims 1 to 7.

9. a calculation unit that acquires an output of a current detection unit that detects a phase current of an AC motor and calculates at least one of an active power and a reactive power of the AC motor; a diagnosis unit that performs a diagnosis regarding deterioration or abnormality of the AC motor based on the frequency component of at least one of the active power and the reactive power, The diagnosing unit performs the diagnosis on at least one of the active power and the reactive power based on a frequency component obtained by a frequency analysis and an amplitude of vibration obtained by a waveform counting method. Diagnostic equipment.

10. a calculation step of acquiring an output of a current detection unit that detects a phase current of an AC motor by a diagnostic device, and acquiring at least one of an active power and a reactive power of the AC motor based on the output of the current detection unit; a diagnosis step of diagnosing deterioration or abnormality of the AC motor based on the frequency component of at least one of the active power and the reactive power by the diagnosis device, In the diagnosis step, the diagnosis is performed on at least one of the active power and the reactive power based on a frequency component obtained by a frequency analysis and an amplitude of vibration obtained by a waveform counting method. Diagnostic methods.

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