Power conversion device, power transmission device, information processing device, and degradation / abnormality diagnosis method

Abstract

To provide a technique for performing diagnosis of the deterioration and abnormalities of an AC motor with a simpler configuration.SOLUTION: A power conversion device 100 includes: an inverter circuit 130 that drives a motor M by using externally input power; a sensor 150 that detects phase current of a circuit between the inverter circuit 130 and the motor M; a monitor unit 1402 that monitors, based on an output of the sensor 150, at least either a predetermined harmonic component of the phase current (for example, a fifth harmonic component or a seventh harmonic component) or an imbalance of the phase current; and a diagnosis unit 1403 that performs diagnosis of a layer short (inter-layer short circuit) of the motor M, based on a result of monitoring by the monitor unit 1402.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] For example, a technique is known for diagnosing electrical deterioration and abnormality in an AC motor, such as a layer short (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5875734 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, a dedicated detector is provided for diagnosing deterioration abnormalities, which may complicate the configuration for determining electrical deterioration abnormalities of the AC motor.

[0005] In view of the above-mentioned problems, an object of the present invention is to provide a technique that is capable of diagnosing deterioration and abnormalities in an AC motor with a simpler configuration. [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 a circuit between the drive unit and the AC motor; a monitoring unit that monitors at least one of a predetermined harmonic component of at least one of a current and a voltage of the AC motor and an imbalance state of at least one of a phase current and a phase voltage of the circuit based on an output of the current detection unit; A diagnosis unit that performs a diagnosis regarding electrical deterioration or abnormality of the AC motor based on a monitoring result of the monitoring unit. picture, the predetermined harmonic component includes at least one of a fifth harmonic component and a seventh harmonic component, The diagnosis unit performs a diagnosis regarding a layer short circuit in a winding of the AC motor based on a monitoring result of at least one of the fifth harmonic component and the seventh harmonic component of at least one of the current and voltage of the AC motor by the monitoring unit. A power converter is provided.

[0007] In another 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 a circuit between the drive unit and the AC motor; Based on the output of the current detection unit, at least one of the d-axis and q-axis currents of the AC motor and the d-axis and q-axis voltages of the AC motor is detected. A given harmonic content for A monitoring unit that monitors the A diagnosis unit that performs a diagnosis regarding a layer short circuit of a winding of the AC motor based on a monitoring result of the monitoring unit. A power converter is provided.

[0008] In another 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 a circuit between the drive unit and the AC motor; Based on the output of the current detection unit, the active power and reactive power of the AC motor are and acquiring a predetermined harmonic component contained in the acquired active power and reactive power. Monitor and monitoring an imbalance state of at least one of a phase current and a phase voltage based on the acquired active power and reactive power. The monitoring department and A diagnosis unit that performs a diagnosis regarding a layer short circuit of a winding of the AC motor based on a monitoring result of the monitoring unit. A power converter is provided.

[0009] In still another embodiment of the present disclosure, A power transmission device provided in an AC transmission path between a power source and an AC motor, a current detection unit that detects a phase current of a circuit between the power source and the AC motor; a monitoring unit that monitors at least one of a predetermined harmonic component of at least one of a current and a voltage of the AC motor and an imbalance state of at least one of a phase current and a phase voltage of the circuit based on an output of the current detection unit; A diagnosis unit that performs a diagnosis regarding electrical deterioration or abnormality of the AC motor based on a monitoring result of the monitoring unit. picture, the predetermined harmonic component includes at least one of a fifth harmonic component and a seventh harmonic component, The diagnosis unit performs a diagnosis regarding a layer short circuit in a winding of the AC motor based on a monitoring result of at least one of the fifth harmonic component and the seventh harmonic component of at least one of the current and voltage of the AC motor by the monitoring unit. A power transfer device is provided.

[0010] In still another embodiment of the present disclosure, a monitoring unit that acquires an output of a current detection unit from a power conversion device including a drive unit that drives an AC motor using power input from an external source and a current detection unit that detects a phase current of a circuit between the drive unit and the AC motor, and monitors, based on the output of the current detection unit, at least one of predetermined harmonic components of at least one of a current and a voltage of the AC motor and an imbalance state of at least one of a phase current and a phase voltage of the circuit; A diagnosis unit that performs a diagnosis regarding electrical deterioration or abnormality of the AC motor based on a monitoring result of the monitoring unit. picture, the predetermined harmonic component includes at least one of a fifth harmonic component and a seventh harmonic component, The diagnosis unit performs a diagnosis regarding a layer short circuit in a winding of the AC motor based on a monitoring result of at least one of the fifth harmonic component and the seventh harmonic component of at least one of the current and voltage of the AC motor by the monitoring unit. An information processing device is provided.

[0011] In still another embodiment of the present disclosure, A deterioration / abnormality diagnosis method that is built into a power conversion device including a drive unit that drives an AC motor using power input from an external source, and a current detection unit that detects a phase current of a circuit between the drive unit and the AC motor, or that is executed by an information processing device that can acquire an output of the current detection unit from the power conversion device, a monitoring step of monitoring at least one of a predetermined harmonic component of at least one of a current and a voltage of the AC motor and an imbalance state of at least one of a phase current and a phase voltage of the circuit based on an output of the current detection unit; A diagnosis step of diagnosing electrical deterioration and abnormality of the AC motor based on a monitoring result of the monitoring step. fruit , the predetermined harmonic component includes at least one of a fifth harmonic component and a seventh harmonic component, In the diagnosis step, a diagnosis regarding a layer short circuit in a winding of the AC motor is performed based on a monitoring result of at least one of the fifth harmonic component and the seventh harmonic component of at least one of a current and a voltage of the AC motor in the monitoring step. A degradation abnormality diagnosis method is provided. Effect of the Invention

[0012] According to the above-described embodiment, it is possible to perform diagnosis regarding deterioration or abnormality of an AC motor with a simpler configuration. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a first example of the configuration of an electric motor abnormality diagnosis system. [Diagram 2] 1 is a functional block diagram showing a first example of the configuration of a power conversion device. [Diagram 3] FIG. 1 is a diagram showing an example of an electromotive force waveform of a stator of an electric motor when a layer short (interlayer short circuit) occurs. [Figure 4] FIG. 4 is a diagram showing a second example of the configuration of the motor abnormality diagnosis system. [Diagram 5] FIG. 4 is a functional block diagram showing a second example of the configuration of a power conversion device. [Figure 6] FIG. 13 is a diagram showing a third example of the configuration of the motor abnormality diagnosis system. [Figure 7] FIG. 11 is a functional block diagram showing a third example of the configuration of a power conversion device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment will be described with reference to the drawings.

[0015] [First example of a motor abnormality diagnosis system] First, a first example of an electric motor abnormality diagnosis system 1 according to the present embodiment will be described with reference to Figs. 1 to 3.

[0016] <Outline of the motor abnormality diagnosis system> FIG. 1 is a diagram showing a first example of the configuration of an electric motor abnormality diagnosis system 1 according to this embodiment.

[0017] The motor abnormality diagnosis system 1 performs diagnosis regarding deterioration abnormality of the motor M. Diagnosis of deterioration abnormality of the motor M includes, for example, determining whether or not there is a deterioration abnormality of the motor M, and determining (estimating) the degree of the deterioration abnormality of the motor M (hereinafter, "degree of deterioration abnormality"). Specifically, the motor abnormality diagnosis system 1 performs diagnosis regarding electrical deterioration abnormality of the motor M. Electrical deterioration abnormality of the motor M includes, for example, a layer short circuit (interlayer short circuit) of a winding (coil) described later.

[0018] The motor abnormality diagnostic system 1 includes a power conversion device 100 and a terminal device 200.

[0019] 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.

[0020] 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).

[0021] The electric motor M (an example of an AC electric motor) uses the three-phase AC power output from the power conversion device 100 to electrically drive production equipment, machinery, and the like installed in a factory.

[0022] 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.

[0023] 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.

[0024] 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 .

[0025] The smoothing circuit 120 includes, for example, a smoothing capacitor.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] Moreover, the smoothing circuit 120 includes, for example, a reactor.

[0030] 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).

[0031] 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.

[0032] 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).

[0033] 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.

[0034] The control device 140 (an example of an information processing device) performs control related to the power conversion device 100.

[0035] 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 composed of 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 by loading a program installed in the auxiliary storage device into the memory device and having the CPU execute the program. The control device 140 also receives external signals and outputs (transmits) signals to the outside through the interface device.

[0036] 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.

[0037] Furthermore, the control device 140 performs, for example, a diagnosis regarding deterioration or abnormality of the electric motor M. Specifically, the control device 140 performs a diagnosis regarding a layer short circuit of the electric motor M. This will be described in detail later.

[0038] 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.

[0039] 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 a circuit between the inverter circuit 130 and the motor M, i.e., phase currents of a U-phase line, a V-phase line, and a W-phase line (hereinafter, respectively, referred to as a "U-phase current", a "V-phase current", and a "W-phase current"). The current sensor may be in a form that utilizes, for example, a CT (Current Transformer). The sensor 150 may also include a voltage sensor that detects a circuit between the inverter circuit 130 and the motor M, i.e., phase voltages of a U-phase line, a V-phase line, and a W-phase line (hereinafter, respectively, referred to as a "U-phase voltage", a "V-phase voltage", and a "W-phase voltage").

[0040] The display device 160 is provided, for example, on the outer surface of the housing of the power conversion device 100. The display device 160 displays information related to the state of the power conversion device 100 under the control of the control device 140.

[0041] The communication device 170 communicates with devices external to the power electronics device 100, such as the terminal device 200, through a predetermined communication line.

[0042] 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.

[0043] The terminal device 200 is provided outside the power conversion device 100 and is used by a user of the power conversion device 100 (electric motor abnormality diagnosis system 1). The terminal device 200 provides various information to the user through a display unit 210, for example, and receives various inputs from the user and transmits them to the power conversion device 100.

[0044] The terminal device 200 may include, for example, a stationary terminal device such as a desktop computer terminal, or a portable terminal device (mobile terminal) such as a smartphone, a tablet terminal, or a laptop computer terminal.

[0045] <Functional configuration of power conversion device> FIG. 2 is a functional block diagram showing a first example of the configuration of the power conversion device 100 (control device 140) according to this embodiment.

[0046] 2, the control device 140 includes an electric motor control unit 1401, a monitoring unit 1402, a diagnosis unit 1403, and a notification unit 1404. The functions of the electric motor control unit 1401, the monitoring unit 1402, the diagnosis unit 1403, and the notification unit 1404 are realized, for example, by a program installed in an auxiliary storage device being loaded into a memory device and executed by a CPU.

[0047] The motor control unit 1401 uses the inverter circuit 130 to control the driving of the motor M. Specifically, the motor control unit 1401 generates a control signal (drive command) for driving the motor M under predetermined operating conditions based on detection data (e.g., detection values ​​of U-phase current, V-phase current, and W-phase current) of the sensor 150, and outputs the control signal to the inverter circuit 130.

[0048] 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.

[0049] The monitoring unit 1402 monitors the state of the electric motor M with respect to electrical deterioration or abnormality, based on the detection data of the sensor 150. Details will be described later.

[0050] The diagnosing unit 1403 diagnoses electrical deterioration or abnormality of the motor M based on the monitoring result of the monitoring unit 1402. Details will be described later.

[0051] The notification unit 1404 notifies the user of the diagnosis result by the diagnosis unit 1403. The notification unit 1404 may, for example, display information related to the diagnosis result on the display device 160. The notification unit 1404 may also transmit a signal including information related to the diagnosis result to the terminal device 200 via the communication device 170. This allows the notification unit 1404 to display information related to the diagnosis result on the display unit 210 of the terminal device 200, and notify the user of the diagnosis result.

[0052] The monitoring unit 1402, the diagnosis unit 1403, and the notification unit 1404 perform processing related to diagnosis of deterioration abnormality of the motor M at a predetermined timing, for example. The predetermined timing is, for example, the timing of power ON of the power conversion device 100. As a result, the control device 140 performs diagnosis of deterioration abnormality of the motor M in accordance with power ON of the power conversion device 100, and when deterioration abnormality occurs or when the degree of deterioration abnormality is relatively high, it can urge the user to stop operation of the motor M. In addition, the predetermined timing may be, for example, the timing when a diagnosis request is input from the user through an input unit provided in the power conversion device 100, or the timing when a diagnosis request is input from the terminal device 200 through the communication device 170. Specifically, when the predetermined timing arrives, the monitoring unit 1402 monitors the state related to deterioration abnormality of the motor M, and the diagnosis unit 1403 performs diagnosis of deterioration abnormality of the motor M based on the monitoring result. Then, the notification unit 1404 notifies the user of the diagnosis result via the display device 160 or the communication device 170. Furthermore, the notification unit 1404 may be configured to notify the user of the diagnosis result when the diagnosis result is something that should be notified to the user. For example, the notification unit 1404 may notify the user of the diagnosis result when a diagnosis result is output indicating that an abnormality has occurred in the electric motor M or when a diagnosis result is output indicating that the deterioration abnormality degree of the electric motor M exceeds a predetermined standard.

[0053] <Outline of diagnosis method for deterioration and abnormality of electric motor> 3 is a diagram showing an example of an electromotive force waveform of the stator of the electric motor M when an electrical deterioration abnormality (layer short circuit) occurs. Specifically, it is a diagram showing a specific example of an electromotive force waveform of the stator of the electric motor M when a layer short circuit occurs in the U phase of the coils of the U phase, V phase, and W phase of the electric motor M.

[0054] When a layer short occurs in the coil (winding) of the stator of an electric motor M, the deterioration of that area progresses relatively slowly and eventually, after an arc discharge occurs, a complete short circuit occurs in which the wires melt together.

[0055] Even if a layer short circuit (interlayer short circuit) occurs in the coil (winding) of the motor M, the motor M can operate in a manner that allows it to fully exhibit the required performance in the early to middle stages of the deterioration abnormality. Therefore, users of the motor M may not be able to recognize the deterioration abnormality of the motor M until an arc discharge occurs in the final stage of the deterioration abnormality caused by the occurrence of a layer short circuit.

[0056] On the other hand, when a layer short occurs in the motor M, in the early stage of the deterioration abnormality, corona discharge (partial discharge) may occur due to the surge voltage of the inverter circuit 130. In particular, when the motor M is a high-voltage motor driven by a relatively high voltage (e.g., several kilovolts), there is a high possibility that the corona discharge will continue to a certain extent. Therefore, by monitoring the occurrence of corona discharge, it is possible to diagnose the layer short of the motor M in the early stage of the deterioration abnormality after the occurrence of the layer short.

[0057] However, corona discharge is difficult to detect unless the wire insulation has been burned to a certain extent, and there is a high possibility that it will disappear immediately if the voltage of the motor M is relatively low. Therefore, if the motor M is a low-voltage motor that is driven by a relatively low voltage (for example, several hundred volts), the occurrence of corona discharge cannot be detected, and as a result, it is not possible to diagnose the occurrence of a layer short in the motor M by monitoring the corona discharge. In other words, if the motor M is a low-voltage motor, the method of monitoring the discharge state of the motor M cannot diagnose (detect) the occurrence of a layer short unless an arc discharge occurs and a complete short circuit occurs.

[0058] Therefore, in this embodiment, the control device 140 performs a diagnosis of the electric motor M regarding a layer short circuit by monitoring the state of the electric motor M regarding electrical deterioration abnormality.

[0059] 3, among the electromotive force waveforms 31, 32, and 33 of the U-phase, V-phase, and W-phase, a disturbance occurs in the electromotive force waveform 31 of the U-phase, in which a layer short occurs in the coil. Specifically, when a layer short occurs in one of the slots of the U-phase coil of the motor M, the electromotive force waveform is disturbed twice (positive and negative) in one period, and a missing portion 31A occurs in the waveform.

[0060] The U-phase electromotive force waveform 31, in which a layer short circuit has occurred in the coil, is not a sine wave and contains many harmonic components. Therefore, the control device 140 can diagnose layer short circuits by monitoring the harmonic components of the current and voltage of the motor M.

[0061] Specifically, among the harmonic components, relatively low-order components are absorbed by the secondary circuit of the motor M and are therefore difficult to detect. Furthermore, among the harmonic components, relatively high-order components are unlikely to occur due to factors such as the spacing of the winding slots of the stator of the motor M, and even if they do occur, they are absorbed by leakage inductance components and resistance components equivalent to a layer short and are therefore difficult to detect. For this reason, the control device 140 performs diagnosis regarding layer shorts in the motor M by monitoring, for example, specific harmonic components (hereinafter referred to as "specific harmonic components") including the fifth and seventh harmonic components of the current and voltage of the motor M.

[0062] Furthermore, the occurrence of a layer short among the U, V, and W phases causes a disturbance in the electromotive force waveform of a portion of the phases (U phase in this example), resulting in an imbalance in the currents and voltages of the three phases of the motor M. For this reason, the control device 140 performs a diagnosis of a layer short of the motor M, for example, by monitoring the imbalance state of the phase currents and phase voltages of the motor M.

[0063] Thus, in this embodiment, the monitoring unit 1402 monitors at least one of the specific harmonic components of the current and voltage of the motor M and the imbalance state of the phase current and phase voltage of the motor M, and the diagnosing unit 1403 diagnoses electrical deterioration and abnormalities of the motor M based on the monitoring results.

[0064] <Specific example of diagnosis of motor deterioration and abnormality> (1) Processing related to monitoring of specific harmonic components of electric motors by the monitoring unit The monitoring unit 1402 may monitor specific harmonic components of the current and voltage of the motor M by performing at least one of the following processes (1-1) to (1-4) (hereinafter, “harmonic component monitoring processes”).

[0065] (1-1) Extraction of specific harmonic components from phase currents and voltages The monitoring unit 1402 may separate the detection data of the phase current and the phase voltage in the frequency domain by frequency analysis, extract specific frequency components corresponding to specific harmonic components of the phase current and the phase voltage, and monitor (recognize) the levels of the specific harmonic components, etc. In this way, the diagnosing unit 1403 can diagnose the presence or absence of a deterioration abnormality (layer short) of the motor M and its degree (degree of deterioration abnormality), etc., by applying a predetermined threshold value, reference value, etc. based on the monitoring result of the monitoring unit 1402 (the levels of specific harmonic components of the phase current and the phase voltage, etc.).

[0066] Specifically, the monitoring unit 1402 may use a fast Fourier transform (FFT) to extract components in a specific frequency range corresponding to specific harmonic components from the detection data of the phase current and phase voltage, and monitor their levels, etc.

[0067] For example, when V / f (torque vector) control is adopted as a control method for the motor M, the voltage becomes a sine wave, and the influence of the disturbance of the electromotive force caused by the layer short is likely to occur in the current. Therefore, the monitoring unit 1402 may extract a specific harmonic component of the phase current from the detection data of the phase current. Also, when slip frequency type (indirect type) vector control is adopted as a control method for the motor M, the current becomes a sine wave, and the influence of the disturbance of the electromotive force caused by the layer short is likely to occur in the voltage. Therefore, the monitoring unit 1402 may extract a specific frequency component of the phase voltage from the detection data of the phase voltage or the data of the command value of the phase voltage. Also, when direct type vector control is adopted as a control method for the motor M, the influence of the disturbance of the electromotive force caused by the layer short may appear in both the current and the voltage. Therefore, the monitoring unit 1402 may extract a specific harmonic component of at least one of the phase current and the phase voltage from the detection data of the phase current or the detection data of the phase voltage or the data of the command value.

[0068] (1-2) Extraction of specific harmonic components from current and voltage on two axes (d-axis and q-axis) The monitoring unit 1402 passes the time series data of the 2-axis current (d-axis current and q-axis current) and the 2-axis voltage (d-axis voltage and q-axis voltage) through a band-pass filter to extract specific harmonic components contained in the 2-axis current and the 2-axis voltage, and monitors (recognizes) their levels, etc. In this way, the diagnosing unit 1403 can diagnose the presence or absence of deterioration abnormality (layer short) of the motor M and its degree (degree of deterioration abnormality), etc., based on the monitoring results of the monitoring unit 1402 (levels of specific harmonic components of the 2-axis current and the 2-axis voltage, etc.).

[0069] Specifically, the monitoring unit 1402 may calculate 2-axis currents (d-axis current and q-axis current) and 2-axis voltages (d-axis voltage and q-axis voltage) based on detection data of phase currents and detection data of phase voltages or command value data. When vector control is adopted as a control method for the electric motor M, the monitoring unit 1402 may use the 2-axis currents and 2-axis voltages calculated by the electric motor control unit 1401 in the process of vector control. Then, the monitoring unit 1402 may pass the time series data of the 2-axis currents and 2-axis voltages through a band-pass filter to extract time series data of specific harmonic components contained in the 2-axis currents and 2-axis voltages and monitor their levels, etc.

[0070] For example, when V / f control is used as the control method for the motor M, the calculated data (time series data) of the 2-axis current may be passed through a band-pass filter to extract time series data of the specific harmonic components contained in the 2-axis current, for the same reason as above. When slip frequency vector control is used as the control method for the motor M, the calculated data (time series data) of the 2-axis voltage may be passed through a band-pass filter to extract time series data of the specific harmonic components contained in the 2-axis voltage. When direct vector control is used as the control method for the motor M, the calculated data of the 2-axis current and / or the 2-axis voltage may be passed through a band-pass filter to extract time series data of the specific harmonic components contained in at least one of the 2-axis current and / or the 2-axis voltage.

[0071] (1-3) Extraction of specific harmonic components from two-axis current deviation The monitoring unit 1402 passes the time series data of the 2-axis current deviation (d-axis current deviation and q-axis current deviation) through a band-pass filter to extract time series data of specific harmonic components contained in the 2-axis current deviation and monitors the level, etc. of the data. This method is limited to cases where direct vector control is adopted as the control method for the motor M. The 2-axis current deviation is calculated by the motor control unit 1401 (magnetic observer) during the vector control process. This allows the diagnosing unit 1403 to diagnose the presence or absence of deterioration abnormality (layer short) of the motor M and its degree (degree of deterioration abnormality), etc., based on the monitoring results of the monitoring unit 1402 (such as the level of the specific harmonic components of the 2-axis current deviation).

[0072] Specifically, the motor control unit 1401 (magnetic observer) may calculate a 2-axis current deviation corresponding to the deviation between a 2-axis current calculated based on detection data of phase currents and an estimated value of the 2-axis current based on a predefined model of the motor M during vector control. Then, the monitoring unit 1402 may pass the calculated data of the 2-axis current deviation through a band-pass filter to extract a specific harmonic component contained in the 2-axis current deviation and monitor its level, etc.

[0073] (1-4) Extraction of specific harmonic components from active and reactive power The monitoring unit 1402 passes the time series data of the active power and the reactive power through a band pass filter to extract the time series data of the specific harmonic components contained in the active power and the reactive power, and monitors the levels, etc. In this way, the diagnosing unit 1403 can diagnose the presence or absence of a deterioration abnormality (layer short circuit) of the motor M and its degree (degree of deterioration abnormality), etc., based on the monitoring result of the monitoring unit 1402 (the level of the time series data of the specific harmonic components, etc.).

[0074] Specifically, the monitoring unit 1402 may calculate two-axis currents and two-axis voltages based on the detected data of phase currents and the detected data of phase voltages or the data of command values, and calculate active power and reactive power by calculating inner products and cross products.The monitoring unit 1402 may then pass the calculated data of active power and reactive power through a band-pass filter to extract time-series data of specific harmonic components contained in the active power and reactive power, and monitor the levels, etc.

[0075] (2) Processing related to monitoring of imbalances in phase currents and phase voltages by the monitoring unit The monitoring unit 1402 may monitor an imbalance state of at least one of the phase current and the phase voltage of the motor M by performing at least one of the following processes (2-1) to (2-3) (hereinafter, “imbalance monitoring process”).

[0076] (2-1) Comparison of phase currents and voltages among three phases The monitoring unit 1402 compares the detected data of the phase currents, the detected data of the phase voltages, or the data of the command values ​​among the three phases (U phase, V phase, and W phase), and monitors the presence or absence of an imbalance in the phase currents and the phase voltages and the level thereof, etc., based on the levels, waveforms, etc. Thus, the diagnosing unit 1403 can apply a predetermined threshold value or reference value based on the monitoring results (presence or absence and level of imbalance in the phase currents and the phase voltages, etc.) output by the monitoring unit 1402, and diagnose the presence or absence of a deterioration abnormality (layer short) of the motor M and its degree (degree of deterioration abnormality), etc.

[0077] (2-2) Calculation of negative sequence current and negative sequence voltage The monitoring unit 1402 calculates a negative-sequence current and a negative-sequence voltage based on the detection data of the phase current and the detection data of the phase voltage or the data of the command value, and monitors the levels, etc. In this way, the diagnosing unit 1403 can diagnose the presence or absence of a deterioration abnormality (layer short) of the motor M and its degree (degree of deterioration abnormality), etc., based on the monitoring results (negative-sequence current and the level of the negative-sequence current, etc.) output by the monitoring unit 1402.

[0078] (2-3) Monitoring (calculation) of active power and reactive power The monitoring unit 1402 calculates the active power and the reactive power in the same manner as described above, and electric power and invalid electric power Based on the calculated data, the diagnosing unit 1403 monitors the presence or absence of an imbalance in the phase currents and the phase voltages, and the level of the imbalance, etc. As a result, the diagnosing unit 1403 can diagnose the presence or absence of a deterioration abnormality (layer short) of the motor M and the degree of the deterioration (degree of deterioration abnormality), etc., based on the monitoring result (the presence or absence of an imbalance in the phase currents and the phase voltages, and the level of the imbalance, etc.) output by the monitoring unit 1402.

[0079] Specifically, the monitoring unit 1402 may monitor the presence or absence of an imbalance in phase currents and phase voltages and the level thereof by monitoring the presence or absence and the degree of a relative increase in reactive power. This is because if an imbalance in phase currents and phase voltages occurs due to the occurrence of a layer short, there is a possibility that reactive power will become relatively large.

[0080] For example, the monitoring unit 1402 may acquire Lissajous waveforms of active power and reactive power, and monitor the presence or absence of an increase in reactive power, the degree of the increase, etc., based on the acquired Lissajous waveforms. In addition, for example, the monitoring unit 1402 may monitor the presence or absence of a relative increase in reactive power, the degree of the increase, etc., based on a comparison between estimated values ​​of reactive power and active power calculated based on a predefined model of the electric motor M and actual calculated values ​​of active power and reactive power.

[0081] (3) Processing by the diagnostic unit The diagnosis unit 1403 diagnoses electrical deterioration abnormalities of the motor M (occurrence of layer shorts) based on at least one of the monitoring results of the monitoring unit 1402, i.e., the monitoring results of the harmonic components of the current and voltage of the motor M, and the monitoring results of the imbalance state of the phase current and phase voltage of the motor M.

[0082] Specifically, when the monitoring unit 1402 performs only one of the monitoring processes (1-1) to (1-4) and (2-1) to (2-3) described above, the diagnosing unit 1403 may perform a diagnosis regarding electrical deterioration abnormality of the motor M based on the monitoring result, as described above.

[0083] Furthermore, when two or more of the above-mentioned monitoring processes (1-1) to (1-3) and (2-1) to (2-3) are performed, the diagnosing unit 1403 performs a diagnosis of electrical deterioration abnormality of the motor M as described above based on the monitoring results of each monitoring process (hereinafter, "individual monitoring results"). Then, the diagnosing unit 1403 outputs a comprehensive diagnosis result (hereinafter, "comprehensive diagnosis result") based on each diagnosis result based on the individual monitoring results (hereinafter, "individual diagnosis result").

[0084] For example, the diagnosis unit 1403 may equally treat the monitoring results of all the monitoring processes and output a comprehensive diagnosis result. Specifically, when abnormality (="1") or no abnormality (="0") is output as an individual diagnosis result, a simple average of the values ​​corresponding to abnormality or no abnormality of all the monitoring processes may be calculated, and the presence or absence of a comprehensive deterioration abnormality may be diagnosed based on the relationship between the average value and a threshold value. Furthermore, when a deterioration abnormality level is output as an individual diagnosis result, a simple average of the deterioration abnormality levels of all the monitoring processes may be calculated, and the average value may be output as a diagnosis result of the comprehensive deterioration abnormality level.

[0085] Also, for example, the diagnosis unit 1403 may output the overall monitoring result by differentiating the priority (weighting) for each monitoring process, so that the individual monitoring result of a monitoring process with a relatively high priority (weighting) has a larger influence on the overall monitoring result. Specifically, when abnormality or no abnormality is output as the individual diagnosis result, a weighted average according to the priority of the numerical values ​​corresponding to abnormality or no abnormality of all the monitoring processes may be calculated, and the presence or absence of an overall deterioration abnormality may be diagnosed based on the relationship between the average value and a threshold. Also, when a deterioration abnormality degree is output as the individual diagnosis result, a weighted average according to the priority of the deterioration abnormality degrees of all the monitoring processes may be calculated, and the average value may be output as the diagnosis result of the overall deterioration abnormality degree.

[0086] (4) Processing of the notification section The notification unit 1404 may notify the user of all diagnostic results via the display device 160, the terminal device 200, or the like, regardless of the contents of the diagnostic results of the diagnosis unit 1403, for example.

[0087] Furthermore, for example, when the diagnosis of the deterioration abnormality of the electric motor M is automatically executed regardless of the user's request, the notification unit 1404 may determine whether or not to notify depending on the contents of the diagnosis result of the diagnosis unit 1403. Specifically, when the diagnosis unit 1403 outputs the presence or absence of an electrical deterioration abnormality (layer short) of the electric motor M as the diagnosis result, the notification unit 1404 may notify the user of the diagnosis result via the display device 160, the terminal device 200, etc., when the diagnosis result indicates that there is an abnormality. Furthermore, when the diagnosis unit 1403 outputs the electrical deterioration abnormality degree of the electric motor M as the diagnosis result, the notification unit 1404 may notify the user of the diagnosis result via the display device 160, the terminal device 200, etc., when the deterioration abnormality degree exceeds a predetermined standard.

[0088] [Second example of motor abnormality diagnosis system] Next, a second example of the motor abnormality diagnosis system according to the present embodiment will be described with reference to Figures 4 and 5. Below, the same reference numerals are used for the same or corresponding configurations as in the above-mentioned first example, and the description will focus on the parts that differ from the above-mentioned first example. Therefore, the description of the same or corresponding contents as in the above-mentioned first example may be simplified or omitted.

[0089] <Outline of the motor abnormality diagnosis system> FIG. 4 is a diagram showing a second example of the configuration of the motor abnormality diagnosis system 1 according to the present embodiment.

[0090] In this example, similar to the first example described above, the motor abnormality diagnosis system 1 includes a power conversion device 100 and a terminal device 200. Furthermore, in this example, unlike the first example described above, the motor abnormality diagnosis system 1 includes a sensor 300.

[0091] The sensor 300 is provided outside the power conversion device 100 and outputs detection data related to the operating state of the electric motor M. The sensor 300 is configured to be able to detect, for example, the rotational position and rotational speed state of the electric motor M. The sensor 300 may be, for example, an encoder. The output (detection data) of the sensor 300 is taken into the power conversion device 100 (control device 140) through a predetermined communication line.

[0092] <Functional configuration of power conversion device> FIG. 5 is a functional block diagram showing a second example of the configuration of the power conversion device 100 (control device 140) according to this embodiment.

[0093] As shown in FIG. 5, the control device 140 includes a motor control unit 1401, a monitoring unit 1402, a diagnosing unit 1403, and a notifying unit 1404, similarly to the first example described above.

[0094] In this example, the motor control unit 1401 employs vector control based on the detection data of the sensor 150 and the detection data of the sensor 300, and outputs a control signal to the inverter circuit 130 to perform drive control in a manner that causes the inverter circuit 130 to drive the motor M.

[0095] In this example, the monitoring unit 1402 uses detection data from the sensor 300 in addition to detection data from the sensor 150 to monitor the state relating to electrical deterioration and abnormality of the motor M. Details will be described later.

[0096] <Specific example of diagnosis of motor deterioration and abnormality> (1) Processing related to monitoring of specific harmonic components of electric motors by the monitoring unit The monitoring unit 1402 may monitor specific harmonic components of the current and voltage of the motor M by performing at least one of the harmonic component monitoring processes (1-1) to (1-4) described above, as in the first example described above.

[0097] (2) Processing related to monitoring of imbalances in phase currents and phase voltages by the monitoring unit The monitoring unit 1402 may monitor an imbalance state of at least one of the phase currents and phase voltages of the motor M by performing at least one of the imbalance monitoring processes (2-1) to (2-4), which are the above-mentioned (2-1) to (2-3) plus the following (2-4).

[0098] (2-4) Monitoring the operating status of motor M The monitoring unit 1402 monitors the operating state of the motor M based on the detection data of the sensor 300. Specifically, the monitoring unit 1402 may extract frequency components of vibrations of the motor M, which correspond to an imbalance state of the phase current or phase voltage, from the detection data of the sensor 300 using FFT, and monitor (recognize) the level, etc. of the frequency components. This allows the diagnosing unit 1403 to diagnose the presence or absence of a deterioration abnormality (layer short) of the motor M, its degree (degree of deterioration abnormality), etc., based on the monitoring results (levels of frequency components of vibrations of the motor M, which correspond to an imbalance state of the phase current or phase voltage, etc.) output by the monitoring unit 1402.

[0099] (3) Processing by the diagnostic unit As in the first example described above, the diagnostic unit 1403 diagnoses electrical deterioration abnormalities (occurrence of layer shorts) of the motor M based on at least one of the monitoring results of the harmonic components of the current and voltage of the motor M and the monitoring results of the imbalance state of the phase current and phase voltage of the motor M.

[0100] Specifically, when the monitoring unit 1402 performs only one of the monitoring processes (1-1) to (1-4) and (2-1) to (2-4) described above, the diagnosing unit 1403 may perform a diagnosis regarding electrical deterioration abnormality of the motor M based on the monitoring result, as described above.

[0101] Furthermore, when two or more of the above-mentioned monitoring processes (1-1) to (1-3) and (2-1) to (2-4) are performed, the diagnosing unit 1403 performs a diagnosis of electrical deterioration abnormality of the motor M based on the monitoring results of each monitoring process (hereinafter, "individual monitoring results") as described above. Then, the diagnosing unit 1403 outputs a comprehensive diagnosis result based on each individual diagnosis result.

[0102] (4) Processing by the Notification Department In this example, the notification unit 1404 may notify the user of the diagnosis result of the diagnosis unit 1403 via the display device 160, the terminal device 200, or the like, in the same manner as in the first example described above.

[0103] [Third example of motor abnormality diagnosis system] Next, a third example of the motor abnormality diagnosis system according to the present embodiment will be described with reference to Fig. 6 and Fig. 7. Below, the same reference numerals are used for configurations that are the same as or correspond to the above-mentioned first and second examples (hereinafter, "first example, etc."), and the description will focus on the parts that differ from the above-mentioned first example, etc. Therefore, the description of the same or corresponding contents as the above-mentioned first example, etc. may be simplified or omitted.

[0104] <Outline of the motor abnormality diagnosis system> FIG. 6 is a diagram showing a third example of the configuration of the motor abnormality diagnosis system 1 according to the present embodiment.

[0105] In this example, similar to the above-described first example, the motor abnormality diagnosis system 1 includes a power conversion device 100 and a terminal device 200. Moreover, in this example, unlike the above-described first example, the motor abnormality diagnosis system 1 includes a server device 400.

[0106] The server device 400 (an example of an external device) is communicatively connected to the power conversion device 100 through a predetermined communication line. The server device 400 is, for example, an on-premise server or a cloud server installed outside a factory in which production equipment, machinery, and the like driven by the electric motor M are installed. The server device 400 may also be, for example, an edge server installed inside the factory or at a location relatively close to the factory.

[0107] The server device 400 receives data on the results of monitoring the state of the electric motor M regarding electrical deterioration and abnormality from the power conversion device 100, and stores the data in an internal non-volatile storage device.

[0108] Furthermore, the server device 400 analyzes the accumulated history data of the monitoring results in chronological order, and monitors the change points in the history data corresponding to the deterioration abnormality (layer short circuit) of the electric motor M. Then, the server device 400 transmits data including the monitoring results (e.g., the presence or absence of the change points) to the power conversion device 100. This enables the power conversion device 100 to perform a diagnosis regarding the electrical deterioration abnormality of the electric motor M, taking into account the history data accumulated in the server device 400.

[0109] <Functional configuration of power conversion device> FIG. 7 is a functional block diagram showing a third example of the configuration of the power conversion device 100 (control device 140) according to this embodiment.

[0110] As shown in FIG. 7, the control device 140 includes a motor control unit 1401, a monitoring unit 1402, a diagnosing unit 1403, and a notifying unit 1404, similarly to the first example and the like described above.

[0111] In this example, when the monitoring unit 1402 outputs the monitoring result, it transmits the data of the monitoring result to the server device 400 via the communication device 170. As described above, when a plurality of monitoring processes are performed, the monitoring result for each of the plurality of monitoring processes (individual monitoring result) is transmitted to the server device 400. In this way, the control device 140 can accumulate the monitoring results of the monitoring unit 1402 in the server device 400.

[0112] When the server device 400 receives a signal including a monitoring result from the power conversion device 100, the server device 400 performs an analysis of change points in the monitoring result history data based on the latest monitoring result included in the signal and the monitoring result history data including past monitoring results stored internally. For example, the server device 400 monitors change points in the monitoring result history data by attempting to detect change points in the history data for each individual monitoring result using a multivariate analysis technique.

[0113] When the monitoring process is completed, the server device 400 transmits a signal including the monitoring results (such as the presence or absence of a change point in the history data for each individual monitoring result and the time elapsed since the change point) (hereinafter, "history monitoring results") to the power conversion device 100 through a predetermined communication line. This enables the power conversion device 100 (control device 140) to acquire the history monitoring results including information regarding the change points in the time series of the history data of the monitoring results by the monitoring unit 1402 from the server device 400.

[0114] In this example, the diagnosis unit 1403 performs diagnosis regarding electrical deterioration abnormalities of the electric motor M based on the monitoring results from the monitoring unit 1402 as well as the historical monitoring results received from the server device 400, which include information regarding change points in the historical data of the monitoring results by the monitoring unit 1402.

[0115] <Specific example of diagnosis of motor deterioration and abnormality> (1) Processing related to monitoring of specific harmonic components of electric motors by the monitoring unit The monitoring unit 1402 may monitor specific harmonic components of the current and voltage of the motor M by performing at least one of the harmonic component monitoring processes (1-1) to (1-4) described above, as in the first example described above.

[0116] (2) Processing related to monitoring of imbalances in phase currents and phase voltages by the monitoring unit As in the first example described above, the monitoring unit 1402 may monitor an imbalance state of at least one of the phase current and the phase voltage of the motor M by performing at least one of the imbalance monitoring processes (2-1) to (2-3) described above.

[0117] (3) Processing by the diagnostic unit The diagnosis unit 1403 performs diagnosis regarding electrical deterioration abnormalities of the electric motor M, taking into consideration not only the latest monitoring results by the monitoring unit 1402 but also historical monitoring results received from the server device 400, the historical monitoring results including information regarding changes in the historical data of the monitoring results by the monitoring unit 1402.

[0118] For example, when the history monitoring result indicates the presence of a change point in the history data of the monitoring result of the monitoring unit 1402, the diagnosis unit 1403 may correct the diagnosis result based on the latest monitoring result of the monitoring unit 1402 in accordance with the elapsed time from the change point, etc. Specifically, the diagnosis unit 1403 may add or multiply a predetermined value corresponding to the elapsed time from the change point, etc. to a numerical value (0 to 1) indicating the presence or absence of a deterioration abnormality of the motor M, which corresponds to the diagnosis result based on the latest monitoring result of the monitoring unit 1402. Similarly, the diagnosis unit 1403 may add or multiply a predetermined value corresponding to the elapsed time from the change point, etc. to a numerical value of the degree of deterioration abnormality of the motor M, which corresponds to the diagnosis result based on the latest monitoring result of the monitoring unit 1402. The predetermined value may be varied so as to become larger as the elapsed time from the change point becomes larger. This is because it is considered that the deterioration abnormality of the motor M progresses as the elapsed time from the change point becomes larger. This allows the control device 140 to perform diagnosis of deterioration or abnormality of the motor M, taking into consideration not only the current electrical state of the motor M based on the latest monitoring result, but also the tendency of changes in the electrical state of the motor M based on the historical data of past monitoring results. Therefore, the control device 140 can improve the accuracy of diagnosis of deterioration or abnormality of the motor M.

[0119] (4) Processing by the Notification Department In this example, the notification unit 1404 may notify the user of the diagnosis result of the diagnosis unit 1403 via the display device 160, the terminal device 200, or the like, in the same manner as in the above-mentioned first example, etc.

[0120] [Other embodiments] Next, another embodiment will be described.

[0121] The contents of the above-described embodiment may be modified or changed as appropriate.

[0122] For example, in the above-described embodiment, the second example (FIGS. 4 and 5) and the third example (FIGS. 6 and 7) of the motor abnormality diagnosis system 1 may be combined. Specifically, in the second example of the motor abnormality diagnosis system 1, a server device 400 may be added, and the monitoring results of the monitoring unit 1402, including the monitoring results (individual monitoring results) from the imbalance monitoring process of (2-4) described above, may be accumulated in the server device 400. Then, the diagnosing unit 1403 may perform a diagnosis of electrical deterioration abnormality of the motor M, taking into consideration the latest monitoring results by the monitoring unit 1402, as well as historical monitoring results including information regarding change points in the historical data of the monitoring results of the monitoring unit 1402, which are received from the server device 400.

[0123] Furthermore, for example, in the above-described embodiment and its variations and modifications, 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 a commercial power source.

[0124] Furthermore, for example, in the above-described embodiment and its modified and altered examples, the power conversion device 100 may generate three-phase AC power for driving the electric motor M based on power input from a DC power source instead of or in addition to power input from a 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.

[0125] Furthermore, for example, in the above-described embodiments and their variations and modifications, 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 production equipment, mechanical equipment, etc. that is electrically driven by an electric motor M.

[0126] Also, for example, in the above-described embodiment and its variations and modifications, the functions of the communication device 170 may be incorporated into the control device 140 (interface device).

[0127] Also, for example, in the above-described embodiment and its modified and altered examples, the server device 400 may be replaced with a host controller that manages a field device including the power conversion device 100 in a factory where production equipment and machinery driven by the electric motor M are installed. The host controller is, for example, an edge controller.

[0128] Also, for example, in the above-described embodiment and examples of modifications and variations thereof, 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 terminal device 200, the server device 400, or a higher-level controller (each of which is an example of an information processing device). Specifically, the functions of the monitoring unit 1402, the diagnosis unit 1403, and the notification unit 1404, which correspond to a diagnosis function regarding electrical deterioration abnormality of the electric motor M, may be transferred to the terminal device 200, the server device 400, or a higher-level controller.

[0129] Also, for example, in the above-described embodiment and examples of modifications and variations thereof, some or all of the functions of the control device 140 may be transferred to another control device mounted on the power conversion device 100. That is, the functions of the control device 140 may be distributed and realized by a plurality of control devices mounted on the power conversion device 100. For example, the function of driving the electric motor M via the inverter circuit 130 and the function of diagnosing the deterioration or abnormality of the electric motor M may be realized by different control devices of the power conversion device 100.

[0130] Also, for example, in the above-mentioned embodiment and its modified and alternating examples, the power conversion device 100 may be omitted, and the motor M may be directly driven by AC power supplied from a commercial power source PS (an example of a power source). In this case, a diagnostic function for deterioration and abnormality of the motor M may be mounted on the circuit breaker BK (an example of a power transmission device). Specifically, a control device built into the circuit breaker BK may perform functions similar to those of the above-mentioned monitoring unit 1402, diagnosing unit 1403, and notifying unit 1404 based on sensors (e.g., a current sensor that detects a phase current, a voltage sensor that detects a phase voltage, etc.) built into the circuit breaker BK.

[0131] [Effect] Next, the operation of the motor abnormality diagnosis system 1 according to this embodiment will be described.

[0132] For example, in the above-mentioned Patent Document 1, it is necessary to additionally provide dedicated devices such as a phase current detector and a zero-phase current detector in order to determine electrical deterioration abnormality, which may complicate the configuration for determining electrical deterioration abnormality of the motor M.

[0133] In addition, for example, it is possible to diagnose the occurrence of a layer short circuit in the motor M by monitoring the discharge state of the coil of the motor M. However, as described above, if the motor M is a low-voltage motor, the occurrence of a layer short circuit can only be detected in the final stage when arc discharge occurs.

[0134] In contrast, in this embodiment, the power conversion device 100 includes an inverter circuit 130, a sensor 150, a monitoring unit 1402, and a diagnosis unit 1403. Specifically, the inverter circuit 130 drives the motor M using power input from the outside (commercial power supply PS). The sensor 150 detects a phase current of a circuit between the inverter circuit 130 and the motor M. The monitoring unit 1402 monitors at least one of a predetermined harmonic component of at least one of the current and voltage of the motor M, and at least one of an imbalance state of at least one of the phase current and phase voltage between the inverter circuit 130 and the motor M, based on the output of the sensor 150. Specifically, the monitoring unit 1402 may monitor at least one of the d-axis current and q-axis current of the motor M, and the d-axis voltage and q-axis voltage of the motor M, based on the output of the sensor 150. The monitoring unit 1402 may also monitor the active power and reactive power of the motor M, based on the output of the sensor 150. A diagnosing unit 1403 performs diagnosis on the electric motor M for deterioration or abnormality based on the monitoring result of the monitoring unit 1402 .

[0135] As a result, the power conversion device 100 can diagnose electrical deterioration abnormality of the motor M using the detection data of the built-in sensor 150. Therefore, it is not necessary to install a dedicated sensor or the like for diagnosing deterioration abnormality of the motor M outside the power conversion device 100, and the power conversion device 100 can diagnose deterioration abnormality of the motor M with a simpler configuration. Furthermore, the power conversion device 100 can find a change in the electrical state due to the occurrence of a layer short, for example, by monitoring the electrical state of the motor M, such as harmonic components of the current and voltage of the motor M and imbalance (imbalance) of the phase current and phase voltage of the motor M. Therefore, even if the motor M is a low-voltage motor, the power conversion device 100 can detect the electrical deterioration abnormality (layer short) at a relatively early stage after the occurrence of the electrical deterioration abnormality.

[0136] In addition, in this embodiment, the power conversion device 100 may include an electric motor control unit 1401. Specifically, the electric motor control unit 1401 may control the inverter circuit 130 based on the output of the sensor 150, and perform drive control to cause the inverter circuit 130 to drive the electric motor M.

[0137] As a result, the power conversion device 100 can perform diagnosis regarding electrical deterioration abnormality of the motor M by also using the sensor 150 utilized for drive control of the motor M. Therefore, specifically, the power conversion device 100 can perform diagnosis regarding deterioration abnormality of the motor M with a simpler configuration.

[0138] In this embodiment, the predetermined harmonic component may include at least one of a fifth harmonic component and a seventh harmonic component.

[0139] As a result, the power conversion device 100 can monitor the fifth harmonic component and the seventh harmonic component of the current and voltage of the motor M, thereby specifically performing a diagnosis regarding electrical deterioration abnormality (layer short circuit) of the motor M.

[0140] In addition, in this embodiment, the monitoring unit 1402 may monitor an imbalance state of at least one of the phase currents and phase voltages in the circuit between the inverter circuit 130 and the motor M by performing at least one of a plurality of imbalance monitoring processes, including monitoring by comparison of at least one of the phase currents and phase voltages of the three phases, monitoring the negative-phase components of at least one of the phase currents and phase voltages, and monitoring the active power and reactive power of the motor M, based on the output of the sensor 150.

[0141] Thereby, the power conversion device 100 can specifically monitor the imbalance state of the phase current and the phase voltage of the motor M. Moreover, the power conversion device 100 can more appropriately monitor the imbalance state of the phase current and the phase voltage of the motor M by combining a plurality of imbalance state monitoring processes.

[0142] In this embodiment, the motor control unit 1401 may perform drive control based on the output of the sensor 150 and detection data relating to the operating state of the motor M (e.g., detection data from the sensor 300) input from outside the power conversion device. The above-mentioned multiple unbalanced state monitoring processes may include monitoring of the operating state of the motor M based on detection data input from outside.

[0143] As a result, when the power conversion device 100 performs vector control of the motor M using detection data related to the operating state (e.g., rotation speed) of the motor M input from the outside, the detection data can also be used to monitor an imbalance state of the phase currents of the motor M. Therefore, the power conversion device 100 can more appropriately diagnose electrical deterioration and abnormality of the motor M by utilizing an existing configuration.

[0144] In this embodiment, the monitoring unit 1402 may perform at least two of a specific harmonic monitoring process and a plurality of imbalance state monitoring processes.

[0145] This allows the power conversion device 100 to use the results of two or more monitoring processes to perform a diagnosis regarding electrical deterioration abnormality (layer short circuit) of the motor M. Therefore, the power conversion device 100 can more appropriately perform a diagnosis regarding electrical deterioration abnormality of the motor M.

[0146] Moreover, in this embodiment, the power conversion device 100 may include a communication device 170. Specifically, the communication device 170 may transmit the monitoring result of the monitoring unit 1402 to the server device 400. Then, the diagnosing unit 1403 may diagnose electrical deterioration or abnormality of the electric motor M based on the history of the monitoring result of the monitoring unit 1402 accumulated in the server device 400.

[0147] This allows the power conversion device 100 to utilize the history of past monitoring results, thereby enabling the power conversion device 100 to more appropriately diagnose electrical deterioration or abnormality of the electric motor M.

[0148] In addition, in this embodiment, the diagnosing unit 1403 may diagnose electrical deterioration or abnormality of the electric motor M by detecting changes over time based on the history of the monitoring results of the monitoring unit 1402.

[0149] This allows the power conversion device 100 to specifically diagnose electrical deterioration or abnormality of the electric motor M using the history of past monitoring results.

[0150] In addition, in this embodiment, the motor M may be directly driven by three-phase AC power input from the commercial power source PS, and the power conversion device 100 may be omitted. In this case, the circuit breaker BK provided in the AC transmission path between the commercial power source PS and the motor M may have functions similar to those of the sensor 150, the monitoring unit 1402, and the diagnosis unit 1403 of the power conversion device 100. That is, the sensor of the circuit breaker BK may detect a phase current of the circuit between the commercial power source PS and the motor M. Furthermore, the monitoring unit of the circuit breaker BK may monitor at least one of a predetermined harmonic component of at least one of the current and voltage of the motor M, and at least one of an imbalance state of at least one of the phase current and phase voltage of the circuit between the inverter circuit 130 and the motor M, based on the output of the sensor 150. Then, the diagnosis unit of the circuit breaker BK may diagnose electrical deterioration abnormality of the motor M based on the monitoring result of the monitoring unit.

[0151] Thus, the circuit breaker BK can diagnose the deterioration abnormality of the motor M with a simpler configuration, similar to the case of the above-mentioned power conversion device 100. Similar to the case of the above-mentioned power conversion device 100, even if the motor M is a low-voltage motor, the circuit breaker BK can detect the electrical deterioration abnormality (layer short) at a relatively early stage after the occurrence of the electrical deterioration abnormality.

[0152] In addition, in this embodiment, the functions of the monitoring unit 1402 and the diagnosing unit 1403 of the power conversion device 100 (control device 140) may be transferred to an information processing device external to the power conversion device 100, such as the terminal device 200, the server device 400, or a higher-level controller. Specifically, the monitoring unit of the information processing device may acquire the output of the sensor 150 from the power conversion device 100, and monitor at least one of a predetermined harmonic component of at least one of the current and voltage of the motor M and at least one of an imbalance state of at least one of the phase current and phase voltage of the circuit between the inverter circuit 130 and the motor M, based on the output of the sensor 150. Then, the diagnosing unit of the information processing device may diagnose electrical deterioration abnormality of the motor M based on the monitoring result of the monitoring unit.

[0153] This allows the information processing device to perform diagnosis of deterioration abnormality of the motor M with a simpler configuration, similar to the above-mentioned power conversion device 100, etc. The information processing device, similar to the above-mentioned power conversion device 100, can detect electrical deterioration abnormality (layer short) at a relatively early stage after the occurrence of the electrical deterioration abnormality, even if the motor M is a low-voltage motor.

[0154] 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]

[0155] 1 Motor abnormality diagnosis system 100 Power conversion device 110 Rectifier circuit 120 Smoothing circuit 130 Inverter circuit (drive unit) 140 Control device (information processing device) 150 Sensor (current detection section) 160 Display device 170 Communication Equipment 200 Terminal device (information processing device) 210 Display section 300 Sensors 400 Server device (information processing device) 1401 Motor control unit (control unit) 1402 Monitoring Department 1403 Diagnostics Department 1404 Notification Department BK Circuit Breaker (Power Transmission Device) 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 a circuit between the drive unit and the AC motor; a monitoring unit that monitors at least one of a predetermined harmonic component of at least one of a current and a voltage of the AC motor and an imbalance state of at least one of a phase current and a phase voltage of the circuit based on an output of the current detection unit; a diagnosis unit that performs a diagnosis regarding electrical deterioration or abnormality of the AC motor based on a monitoring result of the monitoring unit, the predetermined harmonic component includes at least one of a fifth harmonic component and a seventh harmonic component, The diagnosis unit performs a diagnosis regarding a layer short circuit in a winding of the AC motor based on a monitoring result of at least one of the fifth harmonic component and the seventh harmonic component of at least one of the current and the voltage of the AC motor by the monitoring unit. Power conversion equipment.

2. a control unit that controls the drive unit based on an output of the current detection unit and performs drive control to cause the drive unit to drive the AC motor, The power conversion device according to claim 1 .

3. the monitoring unit monitors an imbalance state of at least one of the phase currents and phase voltages of the circuit by performing at least one of a plurality of imbalance state monitoring processes including monitoring by comparison of at least one of the phase currents and phase voltages of the circuit having a plurality of phases, monitoring a negative-phase component of at least one of the phase currents and phase voltages of the circuit, and monitoring active power and reactive power of the AC motor, based on an output of the current detection unit; The power conversion device according to claim 2 .

4. The control unit performs the drive control based on an output of the current detection unit and detection data related to an operating state of the AC motor input from outside the power conversion device, The plurality of imbalance state monitoring processes include monitoring an operating state of the AC motor based on detection data. The power conversion device according to claim 3 .

5. The monitoring unit performs at least two or more monitoring processes among the monitoring process of the predetermined harmonic component and the monitoring processes of the plurality of imbalance states. The power conversion device according to claim 4.

6. a transmission unit that transmits a monitoring result of the monitoring unit to a predetermined external device, The diagnosing unit performs a diagnosis regarding electrical deterioration or abnormality of the AC motor based on a history of monitoring results of the monitoring unit stored in the external device. The power conversion device according to any one of claims 1 to 5.

7. the diagnosing unit performs a diagnosis regarding electrical deterioration or abnormality of the AC motor by detecting a change over time based on a history of the monitoring results of the monitoring unit. The power converter according to claim 6.

8. 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 a circuit between the drive unit and the AC motor; a monitoring unit that monitors predetermined harmonic components related to at least one of a d-axis and a q-axis current of the AC motor and a d-axis and a q-axis voltage of the AC motor based on an output of the current detection unit; A diagnosis unit that performs a diagnosis regarding a layer short circuit of a winding of the AC motor based on a monitoring result of the monitoring unit. Power conversion equipment.

9. 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 a circuit between the drive unit and the AC motor; a monitoring unit that performs at least one of: acquiring active power and reactive power of the AC motor based on an output of the current detection unit, and monitoring a predetermined harmonic component contained in the acquired active power and reactive power; and monitoring an imbalance state of at least one of a phase current and a phase voltage based on the acquired active power and reactive power; A diagnosis unit that performs a diagnosis regarding a layer short circuit of a winding of the AC motor based on a monitoring result of the monitoring unit. Power conversion equipment.

10. A power transmission device provided in an AC transmission path between a power source and an AC motor, a current detection unit that detects a phase current of a circuit between the power source and the AC motor; a monitoring unit that monitors at least one of a predetermined harmonic component of at least one of a current and a voltage of the AC motor and an imbalance state of at least one of a phase current and a phase voltage of the circuit based on an output of the current detection unit; a diagnosis unit that performs a diagnosis regarding electrical deterioration or abnormality of the AC motor based on a monitoring result of the monitoring unit, the predetermined harmonic component includes at least one of a fifth harmonic component and a seventh harmonic component, The diagnosis unit performs a diagnosis regarding a layer short circuit in a winding of the AC motor based on a monitoring result of at least one of the fifth harmonic component and the seventh harmonic component of at least one of the current and the voltage of the AC motor by the monitoring unit. Power transmission device.

11. a monitoring unit that acquires an output of a current detection unit from a power conversion device including a drive unit that drives an AC motor using power input from an external source and a current detection unit that detects a phase current of a circuit between the drive unit and the AC motor, and monitors, based on the output of the current detection unit, at least one of predetermined harmonic components of at least one of a current and a voltage of the AC motor and an imbalance state of at least one of a phase current and a phase voltage of the circuit; a diagnosis unit that performs a diagnosis regarding electrical deterioration or abnormality of the AC motor based on a monitoring result of the monitoring unit, the predetermined harmonic component includes at least one of a fifth harmonic component and a seventh harmonic component, The diagnosis unit performs a diagnosis regarding a layer short circuit in a winding of the AC motor based on a monitoring result of at least one of the fifth harmonic component and the seventh harmonic component of at least one of the current and the voltage of the AC motor by the monitoring unit. Information processing device.

12. A deterioration / abnormality diagnosis method that is built into a power conversion device including a drive unit that drives an AC motor using power input from an external source, and a current detection unit that detects a phase current of a circuit between the drive unit and the AC motor, or that is executed by an information processing device that can acquire an output of the current detection unit from the power conversion device, a monitoring step of monitoring at least one of a predetermined harmonic component of at least one of a current and a voltage of the AC motor and an imbalance state of at least one of a phase current and a phase voltage of the circuit based on an output of the current detection unit; a diagnosis step of diagnosing an electrical deterioration abnormality of the AC motor based on a monitoring result of the monitoring step, the predetermined harmonic component includes at least one of a fifth harmonic component and a seventh harmonic component, In the diagnosis step, a diagnosis regarding a layer short circuit in a winding of the AC motor is performed based on a monitoring result of at least one of the fifth harmonic component and the seventh harmonic component of at least one of a current and a voltage of the AC motor in the monitoring step. A method for diagnosing deterioration abnormalities.

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