JP2024082587A - Diagnostic systems, electric drive units - Google Patents

Abstract

A technique is provided that enables more appropriate diagnosis of abnormalities in an electric motor.
[Solution] A diagnostic system 1 according to one embodiment of the present disclosure comprises an electric motor 120, a power conversion device 110 integrated with the electric motor 120 and supplying driving power to the electric motor 120, a diagnostic sensor 140 built into or attached to the housing of the integrated electric motor 120 and power conversion device 110 and acquiring data representing a first physical quantity relating to the state of the electric motor 120, and a diagnostic device 150 built into or attached to the housing 100H and performing a diagnosis on abnormalities in the electric motor 120 based on the data representing the first physical quantity.
[Selected Figure] Figure 1

Description

This disclosure relates to diagnostic systems, etc.

Conventionally, there is known a technique for diagnosing motor abnormalities (hereinafter, "abnormality diagnosis") based on data on physical quantities related to the state of the motor (e.g., motor current) (see, for example, Patent Document 1).

Patent No. 6824494

However, in Patent Document 1, a current sensor is placed in the wiring between the electric motor and the power conversion device. Therefore, for example, if there is an imbalance in the impedance of the three-phase wiring between the electric motor and the power conversion device, the effect of this may be reflected in the output of the current sensor. As a result, the effect of the impedance imbalance in the wiring may be erroneously diagnosed as an abnormality in the three phases of the electric motor (for example, a break in one of the phases or a layer short).

The purpose of this disclosure is to provide technology that can more appropriately diagnose abnormalities in electric motors.

In order to achieve the above object, in one embodiment of the present disclosure,
An electric motor;
a power conversion device integrated with the electric motor and supplying driving power to the electric motor;
a first sensor that is built into or attached to a housing of the electric motor and the power conversion device that are integrated together, and that acquires data representing a first physical quantity related to a state of the electric motor;
a diagnostic device that diagnoses an abnormality in the electric motor based on the data representing the first physical quantity,
A diagnostic system is provided.

In another embodiment of the present disclosure,
An electric motor;
a power conversion device integrated with the electric motor and supplying driving power to the electric motor;
a first sensor that is built into or attached to a housing of the electric motor and the power conversion device that are integrated together, and that acquires data representing a first physical quantity related to a state of the electric motor;
a diagnostic device that is built into or attached to the housing and performs a diagnosis regarding an abnormality of the electric motor based on data representing the first physical quantity;
An electric drive unit is provided.

The above-described embodiment allows for more appropriate diagnosis of motor abnormalities.

FIG. 1 illustrates an example of a diagnostic system. FIG. 2 is a functional block diagram showing an example of a functional configuration of a control circuit and a diagnostic device. 10A and 10B are diagrams illustrating an example of feature quantities related to an abnormality in an electric motor; 13A and 13B are diagrams illustrating other examples of feature quantities related to an abnormality in an electric motor. FIG. 1 is a diagram illustrating an electric drive system according to a first comparative example. FIG. 2 illustrates an example of an electric drive unit. FIG. 11 is a diagram showing an electric drive unit according to a second comparative example. FIG. 13 is a diagram showing another example of an electric drive unit.

The following describes the embodiment with reference to the drawings.

[Hardware configuration of diagnostic system]
The hardware configuration of a diagnostic system 1 according to this embodiment will be described with reference to FIG.

Figure 1 shows an example of a diagnostic system 1.

As shown in FIG. 1, the diagnostic system 1 includes an electric drive unit 100, a management device 200, and a terminal device 300.

The electric drive unit 100 includes a power conversion device 110, an electric motor 120, a transmission 130, a diagnostic sensor 140, a diagnostic device 150, a display unit 160, and a communication unit 170.

The diagnostic system 1 performs diagnosis (abnormality diagnosis) of abnormalities in the electric motor 120 in the electric drive unit 100 (diagnosis device 150).

The abnormality of the electric motor 120 to be diagnosed by the diagnostic system 1 includes an abnormality of the electric motor 120 caused by a temporary cause and an abnormality (deterioration abnormality) caused by a cumulative cause of the electric motor 120. The abnormality of the electric motor 120 to be diagnosed by the diagnostic system 1 also includes mechanical abnormality and electrical abnormality. The mechanical abnormality of the electric motor 120 to be diagnosed by the diagnostic system 1 includes, for example, a bearing abnormality, a rotor abnormality, a poor connection (misalignment) between the electric motor 120 and the load, etc. The bearing abnormality includes, for example, bearing wear and bearing damage, etc. The rotor abnormality includes, for example, an eccentricity of the rotor of the electric motor 120 and damage to the rotor bar, etc. The electrical abnormality of the electric motor 120 to be diagnosed by the diagnostic system 1 includes, for example, a winding abnormality of the electric motor 120. The winding abnormality of the electric motor 120 includes a broken wire, a partial discharge, insulation deterioration (rare short), etc. Furthermore, the abnormality of the electric motor 120 that is the subject of diagnosis by the diagnosis system 1 may include an abnormality (hereinafter, "load abnormality") caused by an external device (load) connected to the electric motor 120. The load abnormality may include, for example, an overload of the electric motor 120 caused by the load, a light load of the electric motor 120 caused by a mechanical disconnection between the electric motor 120 and the load (e.g., a broken belt), and an abnormal vibration of the electric motor 120 caused by an abnormal vibration of the load.

The abnormality diagnosis of the electric motor 120 includes, for example, a diagnosis of the presence or absence of an abnormality in the electric motor 120. Furthermore, the abnormality diagnosis of the electric motor 120 may include a diagnosis of the presence or absence of signs of an abnormality in the electric motor 120. Furthermore, the abnormality diagnosis of the electric motor 120 may include a diagnosis of the degree of the abnormality in the electric motor 120.

The electric drive unit 100 uses power supplied from a commercial power source PS to drive the electric motor 120 via the power conversion device 110, and outputs the power of the electric motor 120 to an external device via the transmission 130. The electric drive unit 100 drives, for example, production equipment and machinery installed in a factory using the power of the electric motor 120.

The components of the electric drive unit 100 are, for example, built into the housing of the electric drive unit 100. The components of the electric drive unit 100 may also be, for example, attached to the outside of the housing of the electric drive unit 100.

The power conversion device 110 converts three-phase AC power (e.g., R phase, S phase, and T phase) input from the 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 the electric motor 120.

The power conversion device 110 includes a rectifier circuit 10, a smoothing circuit 20, an inverter circuit 30, a current sensor 40, a voltage sensor 50, a gate drive circuit 60, a rotation state sensor 70, and a control circuit 80.

The rectifier circuit 10 is configured to rectify three-phase AC power input from a commercial power source PS and output DC power. The rectifier circuit 10 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 a smoothing circuit 20 through the positive line PL and the negative line NL. For example, as shown in FIG. 1, the rectifier circuit 10 is a bridge-type full-wave rectifier circuit including six semiconductor diodes SD, in which three sets of two semiconductor diodes SD connected in series to form upper and lower arms are connected in parallel. In this case, the input lines of the R phase, S phase, and T phase are connected to the midpoints of the three sets of upper and lower arms, respectively.

The smoothing circuit 20 suppresses and smoothes pulsations in the DC power output from the rectifier circuit 10 and the DC power regenerated from the inverter circuit 30.

For example, as shown in FIG. 1, the smoothing circuit 20 includes a smoothing capacitor 21.

The smoothing capacitor 21 may be provided in parallel with the rectifier circuit 10 and the inverter circuit 30 in a path connecting the positive line PL and the negative line NL.

The smoothing capacitor 21 is repeatedly charged and discharged as appropriate to smooth the DC power output from the rectifier circuit 10 and the DC power output (regenerated) from the inverter circuit 30.

There may be only one smoothing capacitor 21. Alternatively, multiple smoothing capacitors 21 may be arranged, and multiple smoothing capacitors 21 may be connected in parallel or in series between the positive line PL and the negative line NL. Alternatively, the multiple smoothing capacitors 21 may be configured in such a way that multiple series connections of two or more smoothing capacitors are connected in parallel between the positive line PL and the negative line NL.

The smoothing circuit 20 may also include a reactor.

The reactor may be provided on the positive line PL between the rectifier circuit 10 and the smoothing capacitor 21 (specifically, the branch point from the path in which the smoothing capacitor 21 is arranged).

The reactor generates a voltage to appropriately prevent changes in the current, smoothing the DC power output from the rectifier circuit 10 and the DC power output (regenerated) from the inverter circuit 30.

The inverter circuit 30 has positive and negative input terminals connected to the other ends of the positive line PL and the negative line NL. The inverter circuit 30 converts the DC power supplied from the smoothing circuit 20 into three-phase AC power (U phase, V phase, and W phase) having a predetermined frequency and a predetermined voltage by the switching operation of the semiconductor switch SW, and outputs the converted power to the electric motor 120. The semiconductor switch SW is, for example, an insulated gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), or a high electron mobility transistor (HEMT). The semiconductor switch SW is, for example, mainly made of silicon (Si). The semiconductor switch SW may also be mainly made of a wide band gap semiconductor material. Examples of wide band gap semiconductor materials include silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga ₂ O ₃ ), and carbon (diamond: C).

For example, as shown in FIG. 1, the inverter circuit 30 includes six semiconductor switches SW. Specifically, the inverter circuit 30 may include a bridge circuit in which three sets of series-connected semiconductor switches SW constituting upper and lower arms (switch legs) are connected in parallel between the positive line PL and the negative line NL. In this case, the inverter circuit 30 outputs three-phase AC power through three output lines drawn from the midpoints of the three sets of upper and lower arms. In addition, a free wheel diode may be connected in parallel to each of the six semiconductor switches SW.

The current sensor 40 detects the current in each of the three-phase (three wires) output lines of the power conversion device 110, i.e., the phase current in each of the three phases of the electric motor 120. The current sensor 40 detects the current using, for example, a Hall element, a shunt resistor, a magnetic resistance element, a fluxgate, etc., and obtains the detected current value (digital value) using an AD (Analog-Digital) converter. The current sensor 40 outputs a signal corresponding to the detected current value in each of the three phases of the electric motor 120, and the output signal of the current sensor 40 is taken into the control circuit 80.

The current sensor 40 may detect only the current of any two of the three-phase output lines of the power conversion device 110. In this case, the control circuit 80 may obtain (calculate) the current value of the remaining phase from the detected values of the two-phase current. The control circuit 80 may also obtain (calculate) the current value of the three-phase output lines of the power conversion device 110 based on, for example, the current value of the DC link (positive line PL or negative line NL) and the switching pattern of the semiconductor switch SW. In this case, the control circuit 80 may obtain (calculate) the current value of the DC link based on the output of the voltage sensor 50.

The voltage sensor 50 detects the voltage (DC link voltage) between the positive line PL and the negative line NL of the power conversion device 110. The voltage sensor 50 outputs a signal corresponding to the voltage value between the positive line PL and the negative line NL, and the output signal of the voltage sensor 50 is taken into the control circuit 80.

Under the control of the control circuit 80, the gate drive circuit 60 outputs drive signals to the gate terminals of each of the six semiconductor switches SW of the inverter circuit 30 to switch (ON/OFF) the six semiconductor switches SW.

The rotation state sensor 70 acquires data representing physical quantities (e.g., rotation position and rotation speed) related to the rotation state of the electric motor 120. For example, the rotation state sensor 70 is an optical or magnetic encoder. The rotation state sensor 70 outputs a signal corresponding to the detected value of the rotation speed of the electric motor 120, and the output signal of the rotation state sensor 70 is input to the control circuit 80 of the power conversion device 110. In this way, the control circuit 80 can grasp the magnetic pole position and rotation speed of the rotor of the electric motor 120 based on the detection signal of the rotation state sensor 70.

The rotation state sensor 70 may be omitted if sensorless control of the electric motor 120 is performed.

Hereinafter, the current sensor 40, the voltage sensor 50, and the rotation state sensor 70 may be collectively referred to as the "control sensor." In addition, a voltage sensor that detects the voltage of the electric motor 120 may be further provided as a control sensor.

The control circuit 80 uses the power conversion device 110 to control the electric motor 120.

The functions of the control circuit 80 may be realized by any hardware or a combination of any hardware and software. The control circuit 80 is composed of a computer including a CPU (Central Processing Unit), a memory device, an auxiliary storage device, and an interface device, a drive circuit for driving the gate terminal of a semiconductor switch, etc. The memory device is, for example, a static random access memory (SRAM). The auxiliary storage device is, for example, an electrically erasable programmable read-only memory (EEPROM) or a flash memory. The interface device includes, for example, an external interface for connecting to an external recording medium, and a communication interface for communicating with other devices. The control circuit 80 can realize various functions by loading a program installed in the auxiliary storage device into the memory device and executing it on the CPU. The control circuit 80 can also retrieve and install a program from a recording medium through an external interface, and retrieve and install a program from another device through a communication interface.

The control circuit 80 controls the inverter circuit 30 so that the electric motor 120 operates under specified operating conditions, for example, and drives the electric motor 120 under the specified operating conditions.

The functions of the control circuit 80 may be distributed and realized by multiple control circuits mounted on the power conversion device 110.

The electric motor 120 drives external equipment such as production equipment and machinery installed in a factory, as described above. The electric motor 120 is, for example, an AC motor such as an induction motor or a synchronous motor.

The power conversion device 110 and the electric motor 120 are integrated. This allows the length of the three-phase power lines electrically connecting the power conversion device 110 and the electric motor 120 to be relatively short. For example, the power conversion device 110 and the electric motor 120 are integrated by mechanically connecting the housings of both devices to each other. The power conversion device 110 and the electric motor 120 may also be integrated by being built into the same space in a single housing.

The transmission 130 is mechanically connected to the output shaft of the electric motor 120 in a rotatable manner, and changes the speed (increases or decreases) of the output of the electric motor 120 and outputs it to an external device.

The electric motor 120 and the transmission 130 are integrated. This allows the distance between the output shaft of the electric motor 120 and the input shaft of the transmission 130 to be very short, and allows a direct connection between the output shaft of the electric motor 120 and the input shaft of the transmission 130. For example, the electric motor 120 and the transmission 130 are integrated by mechanically connecting the housings of both of them. The electric motor 120 and the transmission 130 may also be integrated by being built into the same space in a single housing.

The diagnostic sensor 140 is used to diagnose abnormalities in the electric motor 120. The diagnostic sensor 140 acquires data representing physical quantities related to the state of the electric motor 120. There may be one diagnostic sensor 140, or there may be multiple diagnostic sensors 140. In the latter case, the multiple diagnostic sensors 140 acquire data representing different types of physical quantities. The output of the diagnostic sensor 140 of the electric motor 120 is input to the diagnostic device 150.

The diagnostic sensor is, for example, a vibration sensor that acquires data representing physical quantities related to the vibration state of the electric motor 120. The vibration sensor is, for example, an acceleration sensor. The output of the vibration sensor reflects the vibration state of the electric motor 120 caused by, for example, bearing abnormalities, misalignment, load abnormalities (abnormal vibration of the load), and rotor abnormalities of the electric motor 120. Therefore, the diagnostic device 150 can diagnose these abnormalities based on the output of the vibration sensor.

The diagnostic sensor 140 may also be a sound sensor (microphone). Since the sound generated by the vibration of the electric motor 120 is reflected in the sound sensor, the diagnostic device 150 can diagnose the same types of abnormalities as the vibration sensor based on the output of the sound sensor.

The diagnostic sensor 140 may also be a ZCT (Zero-phase Current Transformer) that acquires data representing the leakage current of the electric motor 120. This allows the diagnostic device 150 to diagnose winding abnormalities (e.g., partial discharge, layer short, etc.) of the electric motor 120 based on the output of the ZCT.

The diagnostic sensor 140 may also be a voltage sensor that acquires data representing the voltage of the motor 120. The output of the voltage sensor reflects the voltage state of the motor 120 caused by, for example, winding abnormalities, misalignment, load abnormalities, rotor abnormalities, etc. of the motor 120. Therefore, the diagnostic device 150 can diagnose these abnormalities based on the output of the voltage sensor.

The diagnostic sensor 140 may also be a torque sensor that acquires data representing the torque of the electric motor 120. The output of the torque sensor reflects the torque state of the electric motor 120 caused by, for example, winding abnormalities, misalignment, load abnormalities, rotor abnormalities, etc. of the electric motor 120. Therefore, the diagnostic device 150 can diagnose these abnormalities based on the output of the torque sensor.

The diagnostic sensor 140 may also be a temperature sensor that acquires data representing the temperature of the electric motor 120. The output of the temperature sensor reflects the temperature state of the electric motor 120 caused by, for example, a winding abnormality (break in the winding), a load abnormality (overload), a bearing abnormality (bearing wear), etc. of the electric motor 120. Therefore, the diagnostic device 150 can diagnose these abnormalities based on the output of the temperature sensor.

The diagnostic sensor 140 may also be a current sensor that is provided separately from the current sensor 40 and is capable of acquiring data related to the current of the motor 120. The output of the current sensor reflects the current state of the motor 120 caused by, for example, winding abnormalities, misalignment, load abnormalities, rotor abnormalities, etc. of the motor 120. Therefore, the diagnostic device 150 can diagnose these abnormalities based on the output of the current sensor.

The diagnostic sensor 140 may also be a rotational state sensor that is provided separately from the rotational state sensor 70 and is capable of acquiring data on the rotational state (rotational position and rotational speed) of the electric motor 120. The output of the rotational state sensor reflects the state of the rotational speed and rotational position of the electric motor 120 caused by, for example, bearing abnormalities, misalignment, and rotor abnormalities (rotor eccentricity) of the electric motor 120. Therefore, the diagnostic device 150 can diagnose these abnormalities based on the output of the rotational state sensor.

The torque sensor output and the temperature sensor output may be used to control the electric motor 120.

The diagnostic device 150 diagnoses abnormalities in the electric motor 120.

The functions of the diagnostic device 150 may be realized by any hardware or a combination of any hardware and software. The diagnostic device 150 is configured by a computer including a CPU, a memory device, an auxiliary storage device, and an interface device. The memory device is, for example, an SRAM. The auxiliary storage device is, for example, an EEPROM or a flash memory. The interface device includes, for example, an external interface for connecting to an external recording medium and a communication interface for communicating with other devices. The diagnostic device 150 can realize various functions by loading a program installed in the auxiliary storage device into the memory device and executing the program on the CPU. The diagnostic device 150 can also retrieve and install a program from a recording medium through the external interface, and retrieve and install a program from another device through the communication interface.

The functions of the diagnostic device 150 may be distributed and realized by multiple diagnostic devices mounted on the electric drive unit 100. In addition, some or all of the functions of the diagnostic device 150 may be integrated into the control circuit 80.

The display unit 160, under the control of the control circuit 80 and the diagnostic device 150, displays information about the power conversion device 110 to a user (e.g., a worker at a factory in which production equipment or machinery driven by the electric motor 120 is installed). The display unit 160 includes, for example, a warning light, an electronic bulletin board, a liquid crystal display, an organic electroluminescence (EL) display, etc.

The communication unit 170 communicates with devices external to the power conversion device 110 through a specified communication line.

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: Local Area Network) such as a field network constructed in a facility (factory) where the production equipment, machinery, etc. driven by the electric motor 120 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 also include, for example, a wide area network (WAN: Wide Area Network) outside the facility (factory) where the production equipment, machinery, etc. driven by the electric motor 120 are installed. The wide area network may include, for example, a mobile communication network with a base station as its terminal, 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.

The function of the communication unit 170 may be built into the control circuit 80 or the diagnostic device 150 as one function of the interface device.

The management device 200 is provided outside the power conversion device 110. As a higher-level device of the power conversion device 110, the management device 200 is communicably connected to the power conversion device 110 and performs management related to the power conversion device 110 and the electric motor 120.

The management device 200, for example, acquires data on the status of the power conversion device 110 and the electric motor 120 from the power conversion device 110, and performs processing related to the monitoring function of the status of the power conversion device 110 and the electric motor 120. The management device 200 also performs processing related to the interface function related to the interaction between the power conversion device 110 and users such as workers and managers of a factory where the power conversion device 110 and the electric motor 120 are installed. Specifically, the management device 200 may perform processing to provide information on the electric motor 120 and the power conversion device 110, and to receive input from the user and transmit it to the power conversion device 110.

The management device 200 is, for example, an edge controller such as a PLC (Programmable Logic Controller) that manages field devices including the power conversion device 110 in a factory or the like where machinery and production equipment driven by the electric motor 120 are installed. The management device 200 is, for example, a terminal device for managing machinery and production equipment in a factory. 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 the factory, such as a tablet terminal, a smartphone, or a laptop PC. The management device 200 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 production equipment and machinery driven by the electric motor 120 are installed. The server device may also be an edge server that is installed on the premises of a factory or the like where production equipment and machinery electrically driven by the electric motor 120 are installed, or in a facility nearby.

The functions of the management device 200 are realized by any hardware or a combination of any hardware and software. For example, the management device 200 is mainly composed of a computer including a CPU, a memory device, an auxiliary storage device, a high-speed arithmetic device, and an interface device. The management device 200 may also have user interface devices such as an input device and a display device. The memory device includes, for example, an SRAM and a DRAM (Dynamic Random Access Memory). The auxiliary storage device includes, for example, an HDD (Hard Disc Drive), an SSD (Solid State Drive), an EEPROM, a flash memory, etc. The high-speed arithmetic device includes, for example, a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), etc. The interface device includes, for example, an external interface that connects to an external recording medium, and a communication interface for communicating with other devices. The management device 200 can realize various functions by loading a program installed in the auxiliary storage device into the memory device and executing it on the CPU. In addition, the management device 200 can retrieve and install a program from a recording medium through an external interface, and retrieve and install a program from another device through a communication interface. Input devices include, for example, a keyboard, a mouse, a touch panel, etc. Display devices include, for example, a liquid crystal display, an organic EL display, etc.

The terminal device 300 is a user terminal provided outside the power conversion device 110 and used by a user of the diagnostic system 1. The user of the diagnostic system 1 is, for example, a manager or worker of a factory in which production equipment or machinery driven by the electric motor 120 is installed. The terminal device 300, for example, provides the user with various information related to the power conversion device 110 and the electric motor 120, accepts various inputs from the user, and transmits them to the power conversion device 110. The terminal device 300 may acquire information related to the electric motor 120 and the power conversion device 110 via the management device 200, or may directly acquire information related to the electric motor 120 and the power conversion device 110 from the power conversion device 110. Similarly, the terminal device 300 may transmit various inputs from the user to the power conversion device 110 via the management device 200, or may directly transmit inputs from the user to the power conversion device 110.

The terminal device 300 may be, for example, a stationary terminal device such as a desktop PC, or may be, for example, a portable terminal device (mobile terminal) such as a smartphone, a tablet terminal, or a laptop PC.

The functions of the terminal device 300 are realized by any hardware or a combination of any hardware and software. For example, the terminal device 300 is mainly composed of a computer including a CPU, a memory device, an auxiliary storage device, and an interface device, and user interface devices such as an input device and a display device. The memory device includes, for example, an SRAM, a DRAM, etc. The auxiliary storage device includes, for example, an HDD, an SSD, an EEPROM, a flash memory, etc. The interface device includes, for example, an external interface that connects to an external recording medium, and a communication interface for communicating with other devices. The terminal device 300 can realize various functions by loading a program installed in the auxiliary storage device into the memory device and executing it on the CPU. In addition, the terminal device 300 can import and install a program from a recording medium through an external interface, or import and install a program from another device through a communication interface. The input device includes, for example, a button switch, a keyboard, a mouse, a touch panel, etc. The display device includes, for example, a liquid crystal display, an organic EL display, etc.

[Functional configuration of control circuit and diagnostic device]
Next, the functional configurations of the control circuit 80 and the diagnostic device 150 will be described with reference to FIGS.

Figure 2 is a functional block diagram showing an example of the functional configuration of the control circuit 80 and the diagnostic device 150.

As shown in FIG. 2, the control circuit 80 includes a sensor data processing unit 801, a control calculation unit 802, a control command value generation unit 803, and an electric motor control unit 804.

The sensor data processing unit 801 acquires data (hereinafter, "control sensor data") captured from the control sensor, and performs predetermined processing related to the control of the electric motor 120. For example, when the electric motor 120 is vector-controlled, the sensor data processing unit 801 calculates the detection values of the α-axis and β-axis currents based on the output of the current sensor 40 (detection values of the three-phase currents), and calculates the detection values of the d-axis and q-axis currents based on the detection values of the α-axis and β-axis currents.

The control calculation unit 802 performs calculations related to the control of the electric motor 120 based on the output of the sensor data processing unit 801. For example, when speed feedback control of the electric motor 120 is performed, the control calculation unit 802 calculates a current command value for the electric motor 120 based on the deviation between the detected value (or estimated value) of the speed of the electric motor 120 and the speed command value.

The control command value generating unit 803 generates a control command value for a physical quantity (e.g., the voltage of the electric motor 120) that is directly controlled by the power conversion device 110 based on the output of the control calculation unit 802. For example, the control command value generating unit 803 generates command values (voltage command values) for the voltages of the U-phase, V-phase, and W-phase of the electric motor 120 based on the current command value of the electric motor 120 calculated by the control calculation unit 802.

The motor control unit 804 uses the power conversion device 110 to control the motor 120 based on the control command value generated by the control command value generation unit 803. For example, the motor control unit 804 outputs a command signal (gate signal) regarding the control of the inverter circuit 30 to the gate drive circuit 60 so that the voltage of the motor 120 approaches the voltage command value.

The sensor data processing unit 1501 acquires data (hereinafter, "diagnostic sensor data") captured from the diagnostic sensor 140, and performs a predetermined process related to abnormality diagnosis of the electric motor 120. For example, the sensor data processing unit 1501 performs frequency analysis based on time series data (waveform data) of detected values of physical quantities representing the state of the electric motor 120, which correspond to the diagnostic sensor data. The sensor data processing unit 1501 may also perform waveform analysis based on time series data (waveform data) of detected values of physical quantities representing the state of the electric motor 120, which correspond to the diagnostic sensor data. The physical quantities representing the state of the electric motor 120, which correspond to the diagnostic sensor data, are acceleration corresponding to a vibration sensor (acceleration sensor), sound pressure corresponding to a sound sensor (microphone), temperature corresponding to a temperature sensor, etc.

In the waveform analysis, an analysis is performed on the amplitude of the waveform of a specific frequency component contained in the target waveform data. The specific frequency is a specific frequency that has a correlation with an abnormality of the motor 120, for example, a harmonic component (multiplication component) of the rotation frequency of the motor 120. The specific frequency component contained in the target waveform data is extracted, for example, by a specified filter. In this case, if the rotation frequency of the motor 120 fluctuates frequently, the specified filter may be a tracking filter that can extract a specific frequency component by following the fluctuation of the rotation frequency of the motor 120. In addition, when using the detection values of the d-axis and q-axis currents and voltages, the waveform analysis may be performed using the waveform data of the detection values of the d-axis and q-axis currents and voltages as they are. This is because, in the d-axis and q-axis currents and voltages, the components of the rotation frequency of the motor 120 become DC components, and the harmonic components of the rotation frequency appear in the amplitude of the waveform data. For example, the sensor data processing unit 1501 calculates the frequency distribution of the amplitude of each of the multiple waveforms contained in the waveform data for the target waveform data. The term "multiple waveforms" refers to multiple waveforms corresponding to one or half a cycle. The frequency distribution of the amplitudes of the multiple waveforms included in the target waveform data is obtained, for example, by dividing a predefined full range of amplitude magnitude into multiple subranges and tallying up the frequency of the amplitude magnitude of the target waveform data for each subrange. The amplitudes of the multiple waveforms included in the target waveform data are obtained from the target waveform data using, for example, a known waveform counting method. The waveform counting method is, for example, a maximum-minimum method. The waveform counting method may also be a maximum-minimum method, an amplitude method, a level crossing method, or a range bear method. The waveform counting method may also be a rainflow method.

The feature acquisition unit 1502 acquires feature amounts related to an abnormality in the electric motor 120 for physical quantities that represent the state of the electric motor 120 and correspond to the diagnostic sensor data, based on the output of the sensor data processing unit 1501. The feature amount acquired by the feature acquisition unit 1504 may be one or more.

For example, as shown in FIG. 3, the feature acquisition unit 1502 acquires feature amounts related to an abnormality in the electric motor 120 based on the results of the frequency analysis by the sensor data processing unit 1501. In this example, the feature acquisition unit 1502 acquires, as a feature amount, the spectrum value S of the components of specific frequencies f1 and f2 that are correlated with the abnormality in the electric motor 120.

For example, as shown in FIG. 4, the feature acquisition unit 1502 may acquire feature amounts related to an abnormality in the electric motor 120 based on the results of the waveform analysis by the sensor data processing unit 1501. In this example, the feature acquisition unit 1502 acquires, as the feature amount, the total value of the frequency of the range in which the amplitude value exceeds a predetermined threshold value Ath for the frequency distribution of the results of the waveform analysis. This is because, when the electric motor 120 is normal (see FIG. 4A), amplitude values exceeding the relatively large threshold value Ath rarely occur, whereas, when the electric motor 120 is abnormal (see FIG. 4B), the frequency with which amplitude values exceeding the threshold value Ath occur becomes relatively high.

The sensor data processing unit 1503 acquires control sensor data from the control circuit 80 and performs a predetermined process related to abnormality diagnosis of the electric motor 120. For example, the sensor data processing unit 1503 performs frequency analysis based on time series data (waveform data) of detected values of physical quantities representing the state of the electric motor 120, which correspond to the control sensor data. The sensor data processing unit 1501 may also perform waveform analysis based on time series data (waveform data) of detected values of physical quantities representing the state of the electric motor 120, which correspond to the diagnostic sensor data.

The feature acquisition unit 1504 acquires feature amounts related to an abnormality in the electric motor 120 for physical quantities that represent the state of the electric motor 120 and correspond to the diagnostic sensor data, based on the output of the sensor data processing unit 1503. The feature amount acquired by the feature acquisition unit 1504 may be one or more.

For example, similar to the case of the feature acquisition unit 1502, the feature acquisition unit 1504 acquires features related to an abnormality in the electric motor 120 based on the results of the frequency analysis by the sensor data processing unit 1503.

In addition, the feature acquisition unit 1504 may acquire features related to an abnormality in the electric motor 120 based on the results of the waveform analysis by the sensor data processing unit 1503, similar to the case of the feature acquisition unit 1502.

In addition, the feature acquisition unit 1504 may acquire features related to an abnormality in the motor 120 based on control data for the motor 120 (hereinafter, "control data") used in the control circuit 80, instead of the output of the sensor data processing unit 1503. This is because the state of the motor 120 is reflected in the control data for the motor 120. The control data includes, for example, command values of physical quantities (speed command value, torque command value, current command value, voltage command value) that represent the state of the motor 120, and variable control parameters generated by PI (Proportional Integral) control or the like.

For example, the feature acquisition unit 1504 acquires features related to an abnormality in the electric motor 120 based on the results of frequency analysis of the control data, as described above.

Furthermore, the feature acquisition unit 1504 may acquire features related to abnormalities in the electric motor 120 based on the results of waveform analysis of the control data, as described above.

The feature acquisition unit 1504 may also combine both the output of the sensor data processing unit 1503 and the control data to extract features related to an abnormality in the electric motor 120.

For example, the feature amount acquisition unit 1504 combines the feature amount based on the output of the sensor data processing unit 1503 with the feature amount based on the control data to extract the feature amount related to the abnormality of the electric motor 120. Specifically, the feature amount acquisition unit 1504 may extract the feature amount related to the abnormality of the electric motor 120 by performing a predetermined calculation on the feature amount based on each of the output of the sensor data processing unit 1503 and the control data.

The abnormality diagnosis unit 1505 performs abnormality diagnosis of the electric motor 120 based on the features acquired by the feature acquisition unit 1502 and the features acquired by the feature acquisition unit 1504.

For example, the abnormality diagnosis unit 1505 performs an abnormality diagnosis of the electric motor 120 based on the feature acquired by the feature acquisition unit 1502. The abnormality diagnosis unit 1505 also performs an abnormality diagnosis of the electric motor 120 based on the feature acquired by the feature acquisition unit 1504. If either of the two diagnosis results indicates an abnormality, the abnormality diagnosis unit 1505 performs a final diagnosis that the electric motor 120 is abnormal. The abnormality diagnosis unit 1505 also adopts the diagnosis result with the higher degree of abnormality of the two diagnosis results as the final diagnosis result of the degree of abnormality of the electric motor 120. As a result, for example, even if the diagnosis device 150 cannot find a sign of abnormality from one of the feature amounts, it may be able to find the occurrence of an abnormality or a sign of an abnormality from the other feature amount. Therefore, the diagnosis device 150 can more appropriately perform a diagnosis regarding an abnormality of the electric motor 120.

The abnormality diagnosis unit 1505 may also perform an abnormality diagnosis of the electric motor 120 based on the correlation between the feature amount acquired by the feature amount acquisition unit 1502 and the feature amount acquired by the feature amount acquisition unit 1504.

For example, even though the output of the control sensor (current sensor 40) and the control data indicate the control state of the motor 120 under a light load, the diagnostic sensor (temperature sensor) may indicate an unexpected temperature rise of the motor 120. As a result, the feature acquired by the feature acquisition unit 1504 reflects a normal control state under a light load, while the feature acquired by the feature acquisition unit 1502 reflects an abnormal temperature rise of the motor 120. In this case, the abnormality diagnosis unit 1505 can diagnose that there is an abnormality in the motor 120 based on the trade-off in the correlation between the feature acquired by the feature acquisition unit 1502 and the feature acquired by the feature acquisition unit 1504.

In addition, even though the output of the control sensor (current sensor 40) and the control data indicate the control state of the motor 120 under heavy load, the diagnostic sensor (temperature sensor) may indicate a state in which the temperature of the motor 120 does not change or drops. As a result, the feature acquired by the feature acquisition unit 1504 reflects a normal control state under heavy load, while the feature acquired by the feature acquisition unit 1502 reflects an unexpected maintenance or drop in temperature. In this case, the abnormality diagnosis unit 1505 can diagnose that there is an abnormality in the motor 120 based on the trade-off in the correlation between the feature acquired by the feature acquisition unit 1502 and the feature acquired by the feature acquisition unit 1504.

The abnormality diagnosis unit 1505 also performs an analysis of the abnormality of the motor 120 based on the feature acquired by the feature acquisition unit 1502. The abnormality diagnosis unit 1505 also performs an analysis of the abnormality of the motor 120 based on the feature acquired by the feature acquisition unit 1504. Each analysis is, for example, an analysis of the presence or absence of an abnormality performed for each type of abnormality to be diagnosed. The abnormality to be diagnosed is specified in advance by, for example, the type of control sensor, control data, or diagnostic sensor. Then, the abnormality diagnosis unit 1505 performs a diagnosis of the abnormality of the motor 120 based on both analysis results. As a result, the abnormality diagnosis unit 1505 can estimate the cause of the abnormality of the motor 120 when an abnormality exists in the motor 120 based on the correlation between one analysis result and the other analysis result.

For example, while the output of the control sensor (current sensor 40) and the control data do not reflect an abnormality in the electric motor 120, the diagnostic sensor 140 (vibration sensor) may reflect an abnormality in the electric motor 120. As a result, the feature acquired by the feature acquisition unit 1504 does not show any signs of abnormality, while the feature acquired by the feature acquisition unit 1502 shows the occurrence of an abnormality or a sign of abnormality. In this case, the abnormality diagnosis unit 1505 can estimate that the occurrence of an abnormality or a sign of abnormality in the electric motor 120 is due to a mechanical cause.

In addition, while the diagnostic sensor 140 (vibration sensor) does not reflect an abnormality in the electric motor 120, the output of the control sensor (current sensor 40) and the control data may reflect an abnormality in the electric motor 120. As a result, the feature acquired by the feature acquisition unit 1502 does not show any signs of abnormality, while the feature acquired by the feature acquisition unit 1504 shows the occurrence of an abnormality or a sign of an abnormality. In this case, the abnormality diagnosis unit 1505 can estimate that the occurrence of an abnormality or a sign of an abnormality in the electric motor 120 is due to an electrical cause.

The abnormality diagnosis unit 1505 may also perform abnormality diagnosis of the electric motor 120 by combining the features acquired by the feature acquisition unit 1502 and the features acquired by the feature acquisition unit 1504.

For example, the abnormality diagnosis unit 1505 performs abnormality diagnosis of the electric motor 120 using a known multivariate analysis method based on a feature vector that combines the feature acquired by the feature acquisition unit 1502 and the feature acquired by the feature acquisition unit 1504. This allows the abnormality diagnosis unit 1505 to diagnose the degree of abnormality or the presence or absence of an abnormality based on, for example, the distance (e.g., Mahalanobis distance) between the feature vector and an abnormality space defined for each type of abnormality.

The abnormality diagnosis unit 1505 may also diagnose abnormalities in the electric motor 120 based on the feature vector, using a known classifier such as a support vector machine (SVM). This allows the abnormality diagnosis unit 1505 to diagnose the degree of abnormality in the electric motor or the presence or absence of an abnormality, for example, based on the relationship with a hyperplane in the feature vector space that is defined for each type of abnormality.

The notification unit 1506 notifies the user of the diagnosis result by the abnormality diagnosis unit 1505.

For example, the notification unit 1506 displays information about the diagnosis result on the display unit 160. The notification unit 1506 may also transmit a signal including information about the diagnosis result to the management device 200 or the terminal device 300 via the communication unit 170. This allows the notification unit 1506 to notify the user of the diagnosis result via the management device 200 or the terminal device 300.

[Structure of electric drive unit]
Next, the structure of the electric drive unit 100 will be described with reference to FIGS. 5 to 8 in addition to FIG.

The electric drive systems of the first and second comparative examples will be described below, with the same reference numerals used to designate the same components as the electric drive unit 100 of this embodiment.

<Structure of power conversion device and electric motor>
Fig. 5 is a diagram showing an electric drive system according to a first comparative example. Fig. 6 is a diagram showing an example of an electric drive unit 100.

As shown in FIG. 5, the electric drive system according to the first comparative example is configured with a power conversion device 110 and an electric motor 120 separately, and is electrically connected between them by cables or the like corresponding to three-phase (U-phase, V-phase, and W-phase) power lines.

The three-phase power lines between the power conversion device 110 and the motor 120 have a wiring impedance IMP, so the output of the current sensor 40 that detects the current of the power lines between the power conversion device 110 and the motor 120 may reflect the influence of the wiring impedance IMP. The same applies to the case where a voltage sensor that detects the voltage of the motor 120 is provided in addition to the current sensor 40. In particular, in the first comparative example, the power conversion device 110 and the motor 120 are configured separately, so the length of the three-phase power lines between the power conversion device 110 and the motor 120 may be relatively long. As a result, the imbalance of the wiring impedance IMP between the three-phase power lines may become noticeable due to differences in the layout of the three phases. Therefore, the diagnostic device 150 may erroneously diagnose that an imbalance of the three-phase current or voltage of the motor 120 occurs due to a winding abnormality based on the output of the current sensor 40 or voltage sensor that reflects the influence of the imbalance of the three-phase wiring impedance IMP.

In contrast, as shown in FIG. 6, in this embodiment, the power conversion device 110 and the electric motor 120 are integrated and housed in the housing 100H. This allows the length of the three-phase power lines connecting the power conversion device 110 and the electric motor 120 to be very short. This allows the three-phase wiring impedance IMP to be very small, and as a result, the effect of the wiring impedance IMP on the output of the current sensor 40 and the voltage sensor can be suppressed. This allows the diagnostic device 150 to more appropriately diagnose abnormalities in the electric motor 120.

<Motor and transmission structure>
Fig. 7 is a diagram showing an electric drive system according to a second comparative example. Fig. 8 is a diagram showing another example of the electric drive unit 100.

As shown in FIG. 7, in the electric drive system according to the second comparative example, the electric motor 120 and the transmission 130 are configured separately, and the shaft SFT1 extending from the output shaft of the electric motor 120 and the shaft SFT2 extending from the input shaft of the transmission 130 are connected by a coupling CP. Therefore, the connection between the shafts SFT1 and SFT2 may be deflected at the coupling CP, or misalignment (poor connection) may occur at the coupling CP. As a result, the influence of deflection at the coupling CP or the influence of misalignment at the coupling CP may be reflected in the diagnostic sensor 140 (vibration sensor or temperature sensor) attached to the electric motor 120. Therefore, the diagnostic device 150 may not be able to distinguish between a mechanical abnormality (bearing abnormality) of the electric motor 120 and a mechanical abnormality of the transmission 130 based on the output of the diagnostic sensor 140, and may make an incorrect diagnosis.

In addition, if the distance between the electric motor 120 and the transmission 130 becomes particularly long, the length of the coupling CP also becomes long, and as a result, even a very small misalignment in the coupling CP can cause large vibrations.

In addition, since the electric motor 120 and the transmission 130 are provided separately, it is necessary to provide a diagnostic sensor (a vibration sensor or a temperature sensor) in the transmission 130 separate from the diagnostic sensor 140 to diagnose mechanical abnormalities in the transmission 130.

In contrast, as shown in FIG. 8, in this embodiment, the electric motor 120 and the transmission 130 are integrated and built into the housing 100H. This makes it possible to make the distance between the output shaft of the electric motor 120 and the input shaft of the transmission 130 very small, and to directly connect the output shaft of the electric motor 120 and the input shaft of the transmission 130. This suppresses the effects of deflection due to the coupling CP and misalignment at the coupling CP, and the diagnostic device 150 can distinguish between mechanical abnormalities of the electric motor 120 and the transmission 130 and more appropriately diagnose abnormalities in the electric motor 120. In addition, large vibrations caused by misalignment at the coupling CP can be suppressed.

In addition, in this embodiment, the diagnostic sensor 140 is attached to the housing 100H and can measure the vibration and temperature conditions of the electric motor 120 and the transmission 130. Therefore, the diagnostic device 150 can use one diagnostic sensor 140 to diagnose mechanical abnormalities in the electric motor 120 as well as mechanical abnormalities in the transmission 130.

For example, the electric motor 120 and the transmission 130 have different natural frequencies, heat capacities, etc. Therefore, by taking these into consideration, the diagnostic device 150 can distinguish between a mechanical abnormality in the electric motor 120 and a mechanical abnormality in the transmission 130 based on the output of one diagnostic sensor 140. In addition, the diagnostic sensor 140 may be attached to the inside of the housing 100H.

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

The above-described embodiments may be modified or changed as appropriate.

For example, in the above-described embodiment, the power conversion device 110 may generate and output drive power for the electric motor 120 using power input from a DC power source instead of the three-phase AC power input from the commercial power source PS. In this case, for example, the DC voltage input from the DC power source is applied between the positive line PL and the negative line NL. In this case, the rectifier circuit 10 may be omitted.

In addition, in the above-described embodiment, the power conversion device 110 may be a matrix converter capable of directly converting three-phase AC power having R, S, and T phases into three-phase AC power having U, V, and W phases.

In addition, for example, in the above-described embodiment and modified examples, some or all of the functions of the diagnostic device 150 may be transferred to an external device of the electric drive unit 100. For example, some or all of the functions of the diagnostic device 150 may be transferred to the management device 200 or the terminal device 300. In this case, data required for diagnosing abnormalities in the electric motor 120 is transmitted (uploaded) to an external device such as the management device 200 or the terminal device 300 via the communication unit 170.

[Action]
Next, the operation of the diagnostic system and the electric drive unit according to this embodiment will be described.

In this embodiment, the diagnostic system includes an electric motor, a power conversion device, a first sensor, and a diagnostic device. The diagnostic system is the diagnostic system 1 described above. The electric motor is the electric motor 120 described above. The power conversion device is the power conversion device 110 described above. The first sensor is the diagnostic sensor 140. The diagnostic device is, for example, the diagnostic device 150. Specifically, the power conversion device is integrated with the electric motor and supplies driving power to the electric motor. In addition, the first sensor is built into or attached to the housing of the integrated electric motor and power conversion device, and acquires data representing a first physical quantity related to the state of the electric motor. The housing is, for example, the housing 100H described above. The first physical quantity is, for example, the physical quantity related to the vibration described above, a physical quantity related to sound, a physical quantity related to current, voltage, torque, a physical quantity related to the rotation state, etc. Then, the diagnostic device performs a diagnosis of an abnormality in the electric motor based on the data representing the first physical quantity.

In this embodiment, the electric drive unit may also include an electric motor, a power conversion device, a first sensor, and a diagnostic device. The electric drive unit is, for example, the electric drive unit 100 described above.

This allows the distance between the motor and the power conversion device to be extremely short. Therefore, for example, it is possible to suppress the imbalance in the impedance of the three-phase power lines between the power conversion device and the motor, and suppress the effect of this imbalance on the output of the first sensor. Therefore, the diagnostic system can more appropriately diagnose abnormalities in the motor. In addition, by incorporating or attaching the first sensor to the housing associated with the integration of the motor and the power conversion device, it is possible to shorten the wiring from the first sensor to the interface (e.g., the control circuit) that receives the output of the first sensor. Therefore, the effect of noise, etc. on the output of the first sensor is suppressed, and as a result, it is possible to more appropriately diagnose abnormalities in the motor, and it is possible to reduce the space and make the configuration used to diagnose abnormalities in the motor more compact.

In the present embodiment, the diagnostic system may also include a second sensor and a control device. The second sensor may be, for example, the current sensor 40 or the rotation state sensor 70 described above. The control device may be, for example, the control circuit 80 described above. Specifically, the second sensor may acquire data representing a second physical quantity different from the first physical quantity. The second physical quantity may be, for example, the current, voltage, torque, or a physical quantity related to the rotation state described above. The control device may also control the operation of the electric motor using a power conversion device based on the data representing the second physical quantity. The diagnostic device may then diagnose an abnormality in the electric motor by combining at least one of the data representing the first physical quantity, the data representing the second physical quantity, and the control data generated by the control device.

This allows the diagnostic system, etc., to diagnose a wide variety of motor abnormalities, regardless of whether they are electrical or mechanical, by combining data.

In addition, in this embodiment, the diagnostic device may acquire a first feature amount related to an abnormality in the electric motor based on data related to the first physical quantity, acquire a second feature amount based on at least one of data related to the second physical quantity and data for control, and perform a diagnosis of the abnormality in the electric motor based on a combination of the first feature amount and the second feature amount. The first feature amount is, for example, a feature amount acquired by the feature amount acquisition unit 1502 described above. The second feature amount is, for example, a feature amount acquired by the feature amount acquisition unit 1504 described above.

As a result, the diagnostic system, etc., can diagnose a wide variety of motor abnormalities by combining different types of first and second features.

In addition, in this embodiment, the diagnostic device may diagnose abnormalities in the electric motor based on the correlation between the first characteristic amount and the second characteristic amount.

This allows a diagnostic system, etc., to detect the occurrence of an abnormality or signs of an abnormality based on the correlation between different types of first feature amounts and second feature amounts.

In addition, in this embodiment, the diagnostic device may perform a first analysis of the motor abnormality based on data related to the first physical quantity, perform a second analysis of the motor abnormality based on at least one of data related to the second physical quantity and control data, and perform a diagnosis of the motor abnormality based on the correlation between the results of the first analysis and the second analysis.

This allows the diagnostic system, etc., to estimate the cause (type) of the abnormality, for example, by using the correlation between analysis results based on different types of first feature amounts and second feature amounts.

In this embodiment, the first physical quantity may be the temperature of the motor, a physical quantity related to the sound of the motor, or a physical quantity related to the vibration of the motor. And the second physical quantity may be the current or voltage of the motor.

As a result, the diagnostic system etc. can combine data representing the first physical quantity with data representing the second physical quantity to diagnose a wide variety of motor abnormalities, regardless of whether the abnormality is electrical or mechanical in the motor.

In this embodiment, the diagnostic system may also include a transmission. The transmission is, for example, the transmission 130 described above. Specifically, the transmission may be integrated with the electric motor and mechanically connected to the rotating shaft of the electric motor. The first physical quantity may also be a physical quantity related to vibration of the electric motor. The first sensor may also be attached to or built into the housing of the integrated electric motor and transmission.

This allows, for example, the distance between the electric motor and the transmission to be set very short, and the output shaft of the electric motor and the input shaft of the transmission to be directly connected. This makes it possible to suppress deflection at the coupling and misalignment at the coupling, as in the case where a shaft extending from the output shaft of the electric motor and a shaft extending from the input shaft of the transmission are connected by a coupling. As a result, it is possible to suppress a situation in which the influence of deflection at the coupling and misalignment at the coupling is reflected in the output of the first sensor, making it impossible to distinguish between a mechanical abnormality in the electric motor and a mechanical abnormality in the transmission. Thus, the diagnostic system can more appropriately diagnose abnormalities in the electric motor.

In addition, in this embodiment, the diagnostic device may diagnose mechanical abnormalities in the transmission based on data acquired by the first sensor.

This allows the output of the first sensor to be used to diagnose mechanical abnormalities in both the motor and the transmission.

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 of the invention as described in the claims.

1 Diagnostic system 10 Rectifier circuit 20 Smoothing circuit 21 Smoothing capacitor 30 Inverter circuit 40 Current sensor 50 Voltage sensor 60 Gate drive circuit 70 Rotation state sensor 80 Control circuit 100 Electric drive unit 100H Housing 110 Power conversion device 120 Electric motor 130 Transmission 140 Diagnostic sensor 150 Diagnostic device 160 Display unit 170 Communication unit 200 Management device 300 Terminal device 801 Sensor data processing unit 802 Control calculation unit 803 Control command value generation unit 804 Electric motor control unit 1501 Sensor data processing unit 1502 Feature amount acquisition unit 1503 Sensor data processing unit 1504 Feature amount acquisition unit 1505 Abnormality diagnosis unit 1506 Notification unit IMP Wiring impedance NL Negative line PL Positive line PS Commercial power supply SD Semiconductor diodes SFT1, SFT2 Shaft SW Semiconductor switch

Claims (9)

An electric motor;
a power conversion device integrated with the electric motor and supplying driving power to the electric motor;
a first sensor that is built into or attached to a housing of the integrated electric motor and the power conversion device and that acquires data representing a first physical quantity related to a state of the electric motor;
a diagnostic device that diagnoses an abnormality in the electric motor based on the data representing the first physical quantity,
Diagnostic system. a second sensor that acquires data representative of a second physical quantity different from the first physical quantity;
a control device that controls an operation of the electric motor using the power conversion device based on data representing the second physical quantity;
the diagnostic device performs diagnosis regarding an abnormality of the electric motor by combining at least one of the data representing the first physical quantity, the data representing the second physical quantity, and control data generated by the control device.
The diagnostic system of claim 1 . the diagnostic device acquires a first feature amount related to an abnormality in the electric motor based on the data related to the first physical quantity, acquires a second feature amount based on at least one of the data related to the second physical quantity and the control data, and performs a diagnosis of the abnormality in the electric motor based on a combination of the first feature amount and the second feature amount.
The diagnostic system of claim 2 . the diagnostic device performs a diagnosis regarding an abnormality of the electric motor based on a correlation between the first characteristic amount and the second characteristic amount.
The diagnostic system of claim 3 . the diagnostic device performs a first analysis regarding an abnormality of the electric motor based on the data regarding the first physical quantity, performs a second analysis regarding the abnormality of the electric motor based on at least one of the data regarding the second physical quantity and the control data, and performs a diagnosis regarding the abnormality of the electric motor based on a correlation between results of the first analysis and the second analysis.
The diagnostic system of claim 2 . the first physical quantity is a temperature of the electric motor, a physical quantity related to a sound of the electric motor, or a physical quantity related to a vibration of the electric motor;
The second physical quantity is a current or a voltage of the motor.
A diagnostic system according to any one of claims 2 to 5. a transmission that is integrated with the electric motor and mechanically connected to a rotating shaft of the electric motor;
the first physical quantity is a physical quantity related to vibration of the electric motor,
The first sensor is attached to or built into a housing of the electric motor and the transmission which are integrated together;
A diagnostic system according to any one of claims 1 to 5. The diagnostic device performs a diagnosis regarding a mechanical abnormality of the transmission based on the data acquired by the first sensor.
The diagnostic system of claim 7. An electric motor;
a power conversion device integrated with the electric motor and supplying driving power to the electric motor;
a first sensor that is built into or attached to a housing of the electric motor and the power conversion device that are integrated together, and that acquires data representing a first physical quantity related to a state of the electric motor;
a diagnostic device that is built into or attached to the housing and performs a diagnosis regarding an abnormality of the electric motor based on data representing the first physical quantity;
Electric drive unit.

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