CN114675177A

CN114675177A - Power conversion, power transmission, information processing device, and deterioration abnormality diagnosis method

Info

Publication number: CN114675177A
Application number: CN202111253982.1A
Authority: CN
Inventors: 高桥弘; 佐藤以久也; 河野博之
Original assignee: Fuji Electric Co Ltd
Current assignee: Fuji Electric Co Ltd
Priority date: 2020-12-24
Filing date: 2021-10-27
Publication date: 2022-06-28
Also published as: JP2022101344A

Abstract

The invention provides a power conversion, power transmission, information processing device and deterioration abnormality diagnosis method, which can perform diagnosis related to deterioration abnormality of an AC motor with a simpler structure. The power conversion device (100) according to one embodiment of the present invention includes an inverter circuit (130) that drives a motor M using power input from the outside; a sensor (150) that detects a phase current of an electric circuit between the inverter circuit (130) and the motor M; and a monitoring unit (1402) that monitors at least one of a predetermined harmonic component (e.g., a fifth harmonic component and a seventh harmonic component) of the phase current and an unbalanced state of the phase current based on an output of the sensor (150), and a unit (1403) that diagnoses a layer short circuit (layer short) of the motor M based on a monitoring result of the monitoring unit (1402).

Description

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

Technical Field

The present invention relates to a power conversion device and the like.

Background

For example, a technique for diagnosing an electrical deterioration abnormality of an ac motor such as an interlayer short circuit is known (see patent document 1). .

< Prior Art document >

< patent document >

Patent document 1 Japanese patent No. 5875734

Disclosure of Invention

< problems to be solved by the present invention >

However, in patent document 1, a dedicated detector is provided for diagnosing a deterioration abnormality. Therefore, there is a possibility that the configuration for determining the electrical deterioration abnormality of the ac motor becomes complicated.

In view of the above-described problems, an object of the present invention is to provide a technique capable of diagnosing deterioration abnormality of an ac motor with a simpler configuration.

< means for solving the problems >

In order to achieve the above object, according to one embodiment of the present invention, there is provided a power conversion device including:

a drive unit that drives the ac motor using power input from the outside;

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 unbalance 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; and

and a diagnosis unit that performs a diagnosis regarding an electrical deterioration abnormality of the ac motor based on a monitoring result of the monitoring unit.

In another embodiment of the present invention, there is provided a power conversion device including:

a driving unit that drives the ac motor using power input from the outside;

a current detection unit that detects a phase current of an electric circuit between the drive unit and the ac motor;

a monitoring unit that monitors at least one of d-axis and q-axis currents of the ac motor and d-axis and q-axis voltages of the ac motor based on an output of the current detection unit; and

and a diagnosis unit that diagnoses the electrical deterioration abnormality of the ac motor based on a monitoring result of the monitoring unit.

a drive unit that drives the ac motor using power input from the outside;

a monitoring unit that monitors active power and reactive power of the ac motor based on an output of the current detection unit; and

In another embodiment of the present invention, there is provided a power transmission device provided on an ac transmission path between a power supply and an ac motor, the power transmission device including:

a current detection unit that detects a phase current of a circuit between the power supply and the ac motor;

In another embodiment of the present invention, there is provided an information processing apparatus including:

a monitoring unit that acquires an output of the current detection unit from a power conversion device including a driving unit that drives the ac motor using power input from outside and a current detection unit that detects a phase current of the circuit between the driving unit and the ac motor, and 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 the output of the current detection unit; and

In another aspect of the present invention, there is provided a deterioration abnormality diagnosis method performed by an information processing apparatus incorporated in or capable of acquiring an output of a current detection unit from a power conversion apparatus including a drive unit that drives an ac motor using power input from outside and a current detection unit that detects a phase current of a circuit between the drive unit and the ac motor, the deterioration abnormality diagnosis method including:

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 unbalance 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; and

and a diagnosing step of diagnosing an electrical deterioration abnormality of the ac motor based on a monitoring result of the monitoring step.

< effects of the invention >

According to the above embodiment, diagnosis relating to deterioration abnormality of the ac motor can be performed with a simpler configuration.

Drawings

Fig. 1 is a diagram showing a first example of the configuration of a motor abnormality diagnosis system.

Fig. 2 is a functional block diagram showing a first example of the configuration of the power conversion device.

Fig. 3 is a diagram showing an example of an electromotive force waveform of a stator of a motor when a layer short (layer short) occurs.

Fig. 4 is a diagram showing a second example of the configuration of the motor abnormality diagnosis system.

Fig. 5 is a functional block diagram showing a second example of the configuration of the power conversion device.

Fig. 6 is a diagram showing a third example of the configuration of the motor abnormality diagnosis system.

Fig. 7 is a functional block diagram showing a third example of the configuration of the power conversion device.

Detailed Description

Hereinafter, embodiments will be described with reference to the drawings.

[ first example of Motor abnormality diagnosis System ]

First, a first example of the motor abnormality diagnosis system 1 according to the present embodiment will be described with reference to fig. 1 to 3.

< overview of Motor abnormality diagnosis System >

Fig. 1 is a diagram showing a first example of the configuration of a motor abnormality diagnosis system 1 according to the present embodiment.

The motor abnormality diagnosis system 1 performs diagnosis regarding deterioration abnormality of the motor M. The diagnosis of the deterioration abnormality of the motor M includes, for example, determination of presence or absence of the deterioration abnormality of the motor M, determination (estimation) of a degree of the deterioration abnormality of the motor M (hereinafter referred to as "degree of deterioration abnormality"), and the like. Specifically, the motor abnormality diagnosis system 1 performs diagnosis relating to an electrical deterioration abnormality of the motor M. The electrical deterioration abnormality of the motor M includes, for example, a layer short (layer short) of a winding (coil) described later.

The motor abnormality diagnosis system 1 includes a power conversion device 100 and a terminal device 200.

The power conversion device 100 converts three-phase ac power (for example, R-phase, S-phase, and T-phase) input from the commercial power supply PS into three-phase ac power (for example, U-phase, V-phase, and W-phase) having a predetermined voltage and a predetermined frequency, and drives the motor M.

A circuit breaker BK capable of switching a connection state and a disconnection state of an ac transmission path (R-phase, S-phase, and T-phase electric wires) is provided in the ac transmission path between the commercial power source PS and the power conversion device 100. The breaker BK is, for example, mccb (molded Case Circuit breaker).

The motor M (an example of an ac motor) electrically drives production equipment, mechanical equipment, and the like installed in a factory based on the three-phase ac power output from the power conversion device 100.

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

The rectifier circuit 110 is configured to rectify three-phase ac power of R-phase, S-phase, and T-phase input from the commercial power supply PS, and to be able to output dc power. The positive and negative output ends of rectifier circuit 110 are connected to one ends of positive line PL and negative line NL, respectively, and direct current can be output to smoothing circuit 120 through positive line PL and negative line NL. The rectifier circuit 110 includes, for example, six semiconductor diodes, and is a bridge-type full-wave rectifier circuit in which three series-connected bodies of two semiconductor diodes constituting upper and lower bridge arms are connected in parallel.

The smoothing circuit 120 smoothes the dc power output from the rectifier circuit 110 and the dc power regenerated from the inverter circuit 130 by suppressing the ripple.

The smoothing circuit 120 includes, for example, a smoothing capacitor.

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

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 appropriately repeating charging and discharging.

The smoothing capacitor may be one. A plurality of smoothing capacitors may be arranged, and the plurality of smoothing capacitors may be connected in parallel or in series between positive electrode line PL and negative electrode line NL. The plurality of smoothing capacitors may be configured such that a plurality of series-connected bodies of two or more smoothing capacitors are connected in parallel between positive electrode line PL and negative electrode line NL.

The smoothing circuit 120 includes, for example, a reactor.

The reactor may be provided on the positive line PL between the rectifier circuit 110 and the smoothing capacitor (specifically, at a branch point of a path in which the smoothing capacitor is disposed).

The reactor appropriately smoothes the direct current output from the rectifier circuit 110 and the direct current output (regenerated) from the inverter circuit 130 while generating a voltage so as to block a change in current.

The positive and negative input terminals of inverter circuit 130 (an example of a driving unit) are connected to the other ends of positive line PL and negative line NL. The inverter circuit 130 converts the direct current supplied from the smoothing circuit 120 into three-phase alternating current (for example, U-phase, V-phase, and W-phase) having a predetermined frequency and a predetermined voltage by switching operation of the semiconductor switches, and outputs the three-phase alternating current to the motor M, thereby driving the motor M. The Semiconductor switch may be, for example, an insulated Gate Bipolar Transistor (igbt) or a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) made of silicon (Si). The semiconductor switch may be a semiconductor element using a wide band gap semiconductor such as silicon carbide (SiC) or gallium nitride (GaN).

The inverter circuit 130 is configured to include, for example, a bridge circuit including six semiconductor switches, and three sets of series-connected bodies (switch legs) of two semiconductor switches configuring upper and lower bridge arms are connected in parallel between the positive electrode line PL and the negative electrode line NL. Furthermore, the inverter circuit 130 may output three-phase ac power through U-phase lines, V-phase lines, and W-phase lines led out from the connection points of the three sets of upper and lower arms. In addition, the free wheeling diodes may be connected in parallel with the six semiconductor switches, respectively.

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

The functions of the control device 140 may be implemented by any hardware, a combination of any hardware and software, or the like. For example, the control device 140 is mainly configured by a computer including a storage device such as a cpu (central Processing unit), 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 loads a program installed in the auxiliary storage device in the memory device and causes the CPU to execute the program, thereby realizing various functions. The control device 140 receives an external signal via the interface device and outputs (transmits) the signal to the outside.

The control device 140 outputs a drive signal to the inverter circuit 130 (specifically, the gate of each semiconductor switch), for example, and drives the motor M so that the motor M satisfies a predetermined operating condition using the inverter circuit 130. In other words, the control device 140 generates a control signal for driving the motor M in accordance with a predetermined operating condition, and outputs the control signal to the inverter circuit 130.

Further, control device 140 performs diagnosis concerning deterioration abnormality of motor M, for example. Specifically, the control device 140 performs diagnosis regarding an interlayer short circuit of the motor M. The details will be described later.

The sensor 150 is used to acquire detection data relating to the state of the power conversion apparatus 100. The sensor 150 is connected to the control device 140 via, for example, a one-to-one communication line or the like, and a signal corresponding to the detection data (hereinafter referred to as a "detection signal") is introduced into the control device 140. Thus, control device 140 can perform control related to power conversion device 100 based on the detection signal of sensor 150.

Sensor 150 includes, for example, a voltage sensor for detecting a link voltage between positive line PL and negative line NL. The sensor 150 (an example of a current detection unit) includes, for example, a current sensor for detecting phase currents of U-phase, V-phase, and W-phase (hereinafter, referred to as "U-phase current", "V-phase current", and "W-phase current", respectively) in a circuit between the inverter circuit 130 and the motor M. The current sensor may be a current transducer (ct) type. In addition, the sensor 150 may include a voltage sensor for detecting phase voltages (hereinafter, referred to as "U-phase voltage", "V-phase voltage", and "W-phase voltage") of the circuit between the inverter circuit 130 and the motor M, i.e., the U-phase line, the V-phase line, and the W-phase line.

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

Communication device 170 communicates with an apparatus external to power conversion device 100 such as terminal device 200 via a predetermined 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 Area Network (LAN) such as a field Network constructed in a facility (plant) installed in a production facility or a mechanical facility electrically driven by the motor M. The local network may be constructed by wire or wirelessly, and may include both. The predetermined communication line may include, for example, a Wide Area Network (WAN) outside a facility (plant) in which production equipment, mechanical equipment, and the like that are electrically driven by the motor M are installed. The wide area network may include, for example, a mobile communication network terminating in a base station, a satellite communication network using a communication satellite, the internet, and the like. The predetermined communication line may include, for example, a short-range communication line based on a predetermined wireless communication standard such as bluetooth (registered trademark) or WiFi.

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

The terminal device 200 may include a stationary terminal device such as a desktop computer terminal, for example. The terminal device 200 may include a portable (movable) terminal device (portable terminal) such as a smartphone, a tablet terminal, and a laptop computer terminal.

< functional configuration of Power conversion device >

Fig. 2 is a functional block diagram showing a first example of the configuration of the power conversion apparatus 100 (control apparatus 140) according to the present embodiment.

As shown in fig. 2, the control device 140 includes a motor control unit 1401, a monitoring unit 1402, a diagnosis unit 1403, and a notification unit 1404. The functions of the motor control unit 1401, the monitoring unit 1402, the diagnosis unit 1403, and the notification unit 1404 are realized by loading a program installed in the auxiliary storage device into a memory device and executing the program by a CPU, for example.

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

For example, motor control unit 1401 generates command values (hereinafter referred to as "voltage command values") for the U-phase voltage, the V-phase voltage, and the W-phase voltage based on the detection data of sensor 150 and the operating conditions of motor M, and outputs a control signal according to the voltage command values to inverter circuit 130.

The monitoring unit 1402 monitors a state relating to an electrical deterioration abnormality of the motor M based on the detection data of the sensor 150. As will be described in detail later.

The diagnosis unit 1403 performs diagnosis regarding an electrical deterioration abnormality of the motor M based on the monitoring result of the monitoring unit 1402. As will be described in detail later.

The notification section 1404 notifies the user of the diagnosis result based on the diagnosis section 1403. The notification unit 1404 may display information related to the diagnosis result on the display device 160, for example. The notification unit 1404 transmits a signal including information on the diagnosis result to the terminal device 200 via the communication device 170, for example. Thus, the notification unit 1404 can 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.

The monitoring unit 1402, the diagnosis unit 1403, and the notification unit 1404 perform processing related to diagnosis of an abnormal deterioration of the motor M at a predetermined timing, for example. The predetermined timing is, for example, a timing at which the power supply of the power conversion device 100 is ON. Accordingly, the control device 140 can perform diagnosis regarding the deterioration abnormality of the motor M in accordance with the power supply ON of the power conversion device 100, and can urge the user to stop the operation of the motor M when the deterioration abnormality occurs or when the degree of deterioration abnormality is relatively high. The predetermined time may be a time at which a diagnosis request from a user is input through an input unit provided in the power conversion apparatus 100, or a time at which a diagnosis request from a user is input from the terminal apparatus 200 through the communication apparatus 170. Specifically, when a predetermined time arrives, the monitoring unit 1402 monitors a state relating to the deterioration abnormality of the motor M, and the diagnosis unit 1403 diagnoses the deterioration abnormality of the motor M based on the monitoring result. The notification unit 1404 notifies the user of the diagnosis result via the display device 160 and the communication device 170. The notification unit 1404 may notify the user of the diagnosis result when the diagnosis result is the content to be notified to the user. For example, the notification unit 1404 notifies the user of the diagnosis result when outputting the diagnosis result that the motor M has an abnormality, when outputting the diagnosis result that the degree of abnormality in the deterioration of the motor M exceeds a predetermined reference, or the like.

< overview of method for diagnosing deterioration abnormality of Motor >

Fig. 3 is a diagram showing an example of an electromotive force waveform of a stator (stator) of the motor M when an electrical degradation abnormality (interlayer short circuit) occurs. Specifically, the present invention is a diagram showing a specific example of an electromotive force waveform of a stator of the motor M when an interlayer short circuit occurs in the U-phase of the U-phase, the V-phase, and the W-phase coils of the motor M.

When a layer short circuit (layer short) occurs in a coil (winding) of a stator (stator) of the motor M, deterioration of the portion progresses relatively slowly, and finally, after the generation of arc discharge, a complete short circuit state of wire welding is achieved.

Even if a layer short circuit (layer short) occurs in the coil (winding) of the motor M, the motor M can be operated so as to sufficiently exhibit the required performance in the initial stage to the middle stage of the deterioration abnormality. Therefore, there is a possibility that a user of the motor M cannot recognize the deterioration abnormality of the motor M until the arc discharge is generated at the end stage of the deterioration abnormality due to the occurrence of the interlayer short circuit.

On the other hand, if an interlayer short circuit occurs in the motor M, corona discharge (partial discharge) may occur due to a surge voltage of the inverter circuit 130 in an initial stage of the deterioration abnormality. In particular, in the case of a high-voltage motor in which the motor M is driven by a relatively high voltage (for example, several kilovolts), the possibility that corona discharge continues to some extent is high. Therefore, by monitoring the occurrence of corona discharge, it is possible to diagnose the interlayer short circuit of the motor M at the initial stage of the deterioration abnormality after the interlayer short circuit occurs.

However, with regard to corona discharge, if the spread of the coating of the electric wire is not sufficiently detected, the electric wire is likely to disappear immediately when the voltage of the motor M is relatively low. Therefore, in the case where the motor M is a low-voltage motor driven by a relatively low voltage (for example, several hundreds volts), the occurrence of corona discharge cannot be detected, and as a result, diagnosis regarding the occurrence of interlayer short circuit of the motor M cannot be performed by monitoring corona discharge. That is, when the motor M is a low-voltage motor, if the discharge state of the motor M is monitored, the occurrence of the interlayer short circuit cannot be diagnosed (detected) unless the arc discharge is generated and the motor M is in a complete short-circuit state.

In the present embodiment, the control device 140 monitors the state relating to the electrical deterioration abnormality of the motor M, and diagnoses the interlayer short circuit of the motor M.

As shown in fig. 3, the electromotive force waveform 31 of the U-phase, which causes an interlayer short circuit in the coil, among the

electromotive force waveforms

31, 32, and 33 of the U-phase, the V-phase, and the W-phase, respectively, is disturbed. Specifically, if an interlayer short circuit occurs in one slot of the U-phase coil of the motor M, the waveform of the electromotive force is disturbed twice (positive/negative) in one cycle, and a missing portion 31A is generated in the waveform.

The electromotive force waveform 31 of the U-phase in which the interlayer short circuit occurs in the coil is broken down from a sine wave, and therefore contains many harmonic components. Therefore, the control device 140 can perform diagnosis regarding the interlayer short circuit by monitoring the harmonic components of the current and voltage of the motor M.

Specifically, the relatively low-order component of the harmonic component is absorbed by the secondary circuit of the motor M, and therefore is difficult to detect. Further, of the harmonic components, a relatively high-order component is difficult to be generated due to the relationship of the gap between the winding slots of the stator of the motor M, and even if it is generated, it is difficult to detect it because it is absorbed by a leakage inductance component and a resistance component corresponding to an interlayer short circuit. Therefore, the control device 140 performs diagnosis regarding interlayer short-circuiting of the motor M by monitoring a predetermined harmonic component (hereinafter, referred to as a "specific harmonic component") including a fifth harmonic component and a seventh harmonic component of the current and the voltage of the motor M, for example.

Further, the occurrence of the interlayer short circuit in the U-phase, the V-phase, and the W-phase causes disturbance in the electromotive force waveform of a part of the phases (in this example, the U-phase), and as a result, imbalance (unbalance) occurs in the current and voltage of the 3-phase of the motor M. Therefore, controller 140 monitors, for example, the imbalance state of the phase current and the phase voltage of motor M, and diagnoses the interlayer short circuit of motor M.

In this way, in the present embodiment, the monitoring unit 1402 monitors at least one of the imbalance states of the current and the specific harmonic component of the voltage of the motor M and the imbalance states of the phase current and the phase voltage of the motor M, and the diagnosis unit 1403 diagnoses the electrical deterioration abnormality of the motor M based on the monitoring result.

< specific example of processing relating to diagnosis of abnormal deterioration of Motor >

(1) Processing related to monitoring of specific harmonic component of motor by monitoring unit

The monitoring unit 1402 can monitor the specific harmonic component of the current or voltage of the motor M by performing at least one of the following processes (1-1) to (1-4) (hereinafter, referred to as "harmonic component monitoring process").

(1-1) extracting specific higher harmonic components from phase current/phase voltage

The monitoring unit 1402 can separate detection data of the phase current and the phase voltage in the frequency domain by frequency analysis, extract a specific frequency component corresponding to a specific harmonic component of the phase current and the phase voltage, and monitor (recognize) a level (japanese text: レベル) of the specific harmonic component. Thus, the diagnosis unit 1403 can diagnose the presence or absence of a deterioration abnormality (interlayer short circuit) of the motor M, the degree of the deterioration abnormality (degree of deterioration abnormality), and the like by applying predetermined threshold values, reference values, and the like based on the monitoring results (the level of the phase current, the specific harmonic component of the phase voltage, and the like) of the monitoring unit 1402.

Specifically, the monitoring unit 1402 may extract a specific frequency domain component corresponding to the specific harmonic component from the detection data of the phase current and the phase voltage by Fast Fourier Transform (FFT), and monitor the level thereof.

For example, when V/f (torque vector) control is adopted as a control method of the motor M, the voltage becomes sinusoidal, and there is a high possibility that disturbance of electromotive force due to an interlayer short circuit affects current. Therefore, the monitoring unit 1402 can extract a specific harmonic component of the phase current from the detection data of the phase current. In addition, when slip frequency (indirect expression) vector control is employed as a control method of the motor M, the current becomes a sine wave, and there is a high possibility that disturbance of electromotive force due to an interlayer short circuit affects voltage. Therefore, the monitoring unit 1402 may extract the 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. In addition, when direct vector control is employed as a method for controlling the motor M, there is a possibility that the influence of disturbance of electromotive force due to interlayer short-circuit appears in both current and 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, the detection data of the phase voltage, or the data of the command value.

(1-2) extracting specific harmonic components from currents/voltages of two axes (d axis and q axis)

The monitoring unit 1402 passes the time-series data of the two-axis currents (d-axis current and q-axis current) and the two-axis voltages (d-axis voltage and q-axis voltage) through a band-pass filter to extract specific harmonic components contained in the two-axis currents and the two-axis voltages, and monitors (recognizes) the levels thereof. Thus, the diagnosis unit 1403 can diagnose the presence or absence of deterioration abnormality (interlayer short circuit) of the motor M, the degree of deterioration abnormality (degree of deterioration abnormality), and the like based on the monitoring results (the level of specific harmonic components of the two-axis current and the two-axis voltage, and the like) of the monitoring unit 1402.

Specifically, monitoring unit 1402 may calculate the two-axis currents (d-axis current and q-axis current) and the two-axis voltages (d-axis voltage and q-axis voltage) based on the detection data of the phase current, the detection data of the phase voltage, or the data of the command value. When vector control is employed as a control method of the motor M, the monitoring unit 1402 may use the two-axis current and the two-axis voltage calculated by the motor control unit 1401 during vector control. The monitoring unit 1402 may extract time-series data of specific harmonic components included in the two-axis currents and the two-axis voltages and monitor the levels thereof by passing the time-series data of the two-axis currents and the two-axis voltages through a band-pass filter.

For example, when the V/f control is adopted as the control method of the motor M, the time-series data of the specific harmonic component included in the currents in the two axes can be extracted by passing the calculated data (time-series data) of the currents in the two axes through the band-pass filter for the same reason as described above. In addition, when slip frequency vector control is employed as a control method of the motor M, time-series data of a specific harmonic component included in the voltages on the two axes can be extracted by passing the calculation data (time-series data) of the voltages on the two axes through a band-pass filter. In addition, when the direct vector control is adopted as the control method of the motor M, the time series data of the specific harmonic component contained in at least one of the currents in the two axes and the voltages in the two axes can be extracted by passing the calculation data of the currents in the two axes and the voltages in the two axes through the band pass filter.

(1-3) extracting specific higher harmonic components from the biaxial current deviation

The monitoring unit 1402 passes the time-series data of the biaxial current deviation (d-axis current deviation and q-axis current deviation) through a band-pass filter to extract time-series data of a specific harmonic component contained in the biaxial current deviation and monitor the level thereof. This method is limited to the case where direct vector control is adopted as the control method of the motor M. The two-axis current deviation is calculated by a motor control unit 1401 (magnetic observer) during vector control. Thus, the diagnosis unit 1403 can diagnose the presence or absence of deterioration abnormality (interlayer short circuit) of the motor M, the degree thereof (degree of deterioration abnormality), and the like based on the monitoring result (the level of a specific harmonic component of the biaxial current deviation, and the like) of the monitoring unit 1402.

Specifically, the motor control unit 1401 (a magnetic observer) may calculate a two-axis current deviation corresponding to a deviation between a two-axis current calculated based on detected data of the phase current and an estimated value of the two-axis current based on a model of the motor M, which is predetermined in advance, during the vector control. The monitoring unit 1402 passes the calculated data of the two-axis current deviation through a band-pass filter, thereby extracting a specific harmonic component included in the two-axis current deviation and monitoring the level thereof.

(1-4) extracting specific harmonic components from the active power and the reactive power

The monitoring unit 1402 passes the time-series data of the real power and the reactive power through a band-pass filter, thereby extracting time-series data of a specific harmonic component included in the real power and the reactive power, and monitoring the level thereof. Thus, the diagnosis unit 1403 can diagnose the presence or absence of a deterioration abnormality (interlayer short circuit) of the motor M, the degree of the deterioration abnormality (degree of deterioration abnormality), and the like, by giving the monitoring result (the level of the time-series data of the specific harmonic component and the like) of the monitoring unit 1402.

Specifically, monitoring unit 1402 may calculate the two-axis current and the two-axis voltage based on the detection data of the phase current, the detection data of the phase voltage, or the data of the command value, and may calculate the active power and the reactive power by calculating the inner product and the outer product. Then, the monitoring unit 1402 passes the calculated data of the real power and the reactive power through the band pass filter to extract time-series data of the specific harmonic component included in the real power and the reactive power, and monitors the level thereof.

(2) Processing relating to monitoring of imbalance state of phase current/phase voltage by monitoring unit

The monitoring unit 1402 monitors the 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 referred to as an "imbalance monitoring process").

(2-1) phase current/phase voltage 3-phase comparison

The monitoring unit 1402 compares the detection data of the phase current, the detection data of the phase voltage, or the data of the command value among the 3 phases (U-phase, V-phase, and W-phase), and monitors the presence or absence of imbalance (imbalance) of the phase current and the phase voltage, the level thereof, and the like based on the level, the waveform, and the like thereof. Thus, the diagnosis unit 1403 can diagnose the presence or absence of a deterioration abnormality (interlayer short circuit) of the motor M, the degree thereof (degree of deterioration abnormality), and the like by applying predetermined threshold values and reference values based on the monitoring results (presence or absence of imbalance of the phase current and the phase voltage, the level thereof, and the like) output from the monitoring unit 1402.

(2-2) calculation of reverse phase Current/reverse phase Voltage

The monitoring unit 1402 calculates an inverted current and an inverted voltage based on the detection data of the phase current, the detection data of the phase voltage, or the data of the command value, and monitors the level thereof. Thus, the diagnosis unit 1403 diagnoses the presence or absence of a deterioration abnormality (interlayer short circuit) of the motor M, the degree thereof (degree of deterioration abnormality), and the like, based on the monitoring results (the reverse phase current, the level of the reverse phase current, and the like) output from the monitoring unit 1402.

(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 monitors the presence or absence of imbalance (unbalance) of the phase current and the phase voltage, the level thereof, and the like based on the calculation data of the valid data and the invalid data. Thus, the diagnosis unit 1403 can diagnose the presence or absence of a deterioration abnormality (interlayer short circuit) of the motor M, the degree of the deterioration abnormality (degree of deterioration abnormality), and the like, based on the monitoring results (presence or absence of an unbalanced state of the phase current and the phase voltage, the level thereof, and the like) output from the monitoring unit 1402.

Specifically, the monitoring unit 1402 monitors the presence or absence of a relative increase in reactive power and the degree of the increase, and monitors the presence or absence of an unbalanced state (imbalance) of phase current and phase voltage, the level thereof, and the like. This is because if an unbalanced state of the phase current and the phase voltage occurs due to the occurrence of the interlayer short circuit, the reactive power may be relatively increased.

For example, the monitoring unit 1402 may acquire lissajous waveforms of the active power and the reactive power, and monitor the presence or absence of an increase, the degree of the increase, and the like of the reactive power based on the acquired lissajous waveforms. For example, the monitoring unit 1402 may monitor the presence or absence of a relative increase in reactive power, the degree of increase, and the like, based on comparison between an estimated value of reactive power and active power calculated based on a predetermined model of the motor M and an actual calculated value of active power and reactive power.

(3) Processing of diagnostic section

The diagnosis unit 1403 performs diagnosis regarding an electrical deterioration abnormality (occurrence of an interlayer short circuit) of the motor M based on at least one of the monitoring results of the monitoring unit 1402, that is, the monitoring results of the harmonic components of the current and voltage of the motor M and the monitoring results of the imbalance states of the phase current and phase voltage of the motor M.

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

When two or more of the above-described monitoring processes (1-1) to (1-3) and (2-1) to (2-3) are performed, the diagnostic unit 1403 performs a diagnosis regarding the electrical deterioration abnormality of the motor M as described above based on the monitoring result (hereinafter, referred to as "individual monitoring result") of each monitoring process. The diagnostic unit 1403 then outputs a comprehensive diagnostic result (hereinafter referred to as a "comprehensive diagnostic result") based on each diagnostic result (hereinafter referred to as a "separate diagnostic result") based on the separate monitoring results.

For example, the diagnosis unit 1403 may treat the monitoring results of all the monitoring processes equally and output the comprehensive diagnosis result. Specifically, as a result of the individual diagnosis, when abnormality ("1") or abnormality ("0") is output, a simple average value of numerical values corresponding to the presence or absence of abnormality in all the monitoring processes may be calculated, and the presence or absence of the comprehensive deterioration abnormality may be diagnosed by giving a relationship between the average value and a threshold value. In addition, when the degree of abnormality deterioration is output as a result of the individual diagnosis, a simple average value of the degrees of abnormality deterioration in all the monitoring processes may be calculated, and the average value may be output as a result of the diagnosis of the comprehensive degree of abnormality deterioration.

For example, the diagnostic unit 1403 may make the priorities (weights) different for each monitoring process, and output the integrated monitoring result so that the influence of the individual monitoring results of the monitoring processes having relatively high priorities (weights) on the integrated monitoring result becomes large. Specifically, in the case where there is an abnormality or no abnormality is output as the individual diagnosis result, it is possible to calculate a weighted average value of the priority degrees of the numerical values corresponding to the presence or absence of an abnormality according to all the monitoring processes, and diagnose the presence or absence of comprehensive deterioration abnormality based on Seki of the average value and the threshold value. In the case where the degree of abnormality deterioration is output as a result of individual diagnosis, a weighted average value of the degrees of abnormality deterioration according to their priorities with respect to all the monitoring processes may be calculated and output as a result of comprehensive diagnosis of the degree of abnormality deterioration.

(4) Processing of notification section

The notification unit 1404 may notify the user of all the diagnosis results via the display device 160, the terminal device 200, and the like, for example, regardless of the contents of the diagnosis results of the diagnosis unit 1403.

For example, when the diagnosis of the abnormal deterioration of the motor M is not automatically performed in response to a request from the user, the notification unit 1404 may determine whether or not to notify based on the content of the diagnosis result of the diagnosis unit 1403. Specifically, the notification unit 1404 may notify the user of the diagnosis result through the display device 160, the terminal device 200, or the like when the diagnosis result indicates the presence or absence of the electrical deterioration abnormality (interlayer short circuit) of the motor M is output as the diagnosis result self-diagnosis unit 1403. The notification unit 1404 may notify the user of the diagnosis result through the display device 160, the terminal device 200, and the like when the degree of deterioration abnormality exceeds a predetermined reference when the self-diagnosis unit 1403 outputs the degree of electric deterioration abnormality of the motor M as the diagnosis result.

[ second example of Motor abnormality diagnostic System ]

Next, a second example of the motor abnormality diagnosis system according to the present embodiment will be described with reference to fig. 4 and 5. Hereinafter, the same or corresponding configurations as those of the first example will be given the same reference numerals, and portions different from those of the first example will be mainly described. Therefore, the description of the same or corresponding contents as those of the first example may be abbreviated or omitted.

< overview of Motor abnormality diagnosis System >

Fig. 4 is a diagram showing a second example of the configuration of the motor abnormality diagnosis system 1 of the present embodiment.

In this example, as in the case of the first example, the motor abnormality diagnosis system 1 includes the power conversion device 100 and the terminal device 200. In this example, unlike the first example, the motor abnormality diagnostic system 1 includes the sensor 300.

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

< functional configuration of Power conversion device >

Fig. 5 is a functional block diagram showing a second example of the configuration of the power conversion apparatus 100 (control apparatus 140) according to the present embodiment.

As shown in fig. 5, the control device 140 includes a motor control unit 1401, a monitoring unit 1402, a diagnosis unit 1403, and a notification unit 1404, as in the case of the first example.

In this example, the motor control unit 1401 performs drive control such that a control signal is output to the inverter circuit 130 by vector control based on the detection data of the sensor 150 and the detection data of the sensor 300, and the inverter circuit 130 drives the motor M.

In this example, the monitoring unit 1402 monitors a state relating to an electrical deterioration abnormality of the motor M using the detection data of the sensor 300 in addition to the detection data of the sensor 150. The details will be described later.

(1) Processing relating to monitoring of specific harmonic components of a motor by a monitoring unit

As in the case of the first example, the monitoring unit 1402 monitors the specific harmonic component of the current or voltage of the motor M by performing at least one of the harmonic component monitoring processes (1-1) to (1-4) described above.

The monitoring unit 1402 can monitor the imbalance state of at least one of the phase current and the phase voltage of the motor M by adding at least one of the imbalance monitoring processes (2-1) to (2-4) below to the above-described processes (2-1) to (2-3).

(2-4) monitoring of operating State 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, from the detection data of the sensor 300, a frequency component of the vibration of the motor M corresponding to the imbalance state of the phase current and the phase voltage by the FFT, and monitor (recognize) the level (level) thereof. Thus, the diagnosis unit 1403 can diagnose the presence or absence of a deterioration abnormality (interlayer short circuit) of the motor M, the degree of the deterioration abnormality (degree of deterioration abnormality), and the like, based on the monitoring result (the level of the frequency component of the vibration of the motor M corresponding to the unbalanced state of the phase current and the phase voltage) output from the monitoring unit 1402.

(3) Processing by a diagnostic section

As in the case of the first example, the diagnosis unit 1403 performs diagnosis regarding an electrical deterioration abnormality (occurrence of an interlayer short circuit) 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 states of the phase current and phase voltage of the motor M.

Specifically, the diagnosis unit 1403 may perform diagnosis regarding the electrical deterioration abnormality of the motor M based on the monitoring result when the monitoring unit 1402 performs the monitoring process of any one of the above-described (1-1) to (1-4) and (2-1) to (2-4), as described above.

When two or more types of monitoring processes of (1-1) to (1-3) and (2-1) to (2-4) are performed, the diagnostic unit 1403 performs a diagnosis regarding the electrical deterioration abnormality of the motor M as described above based on the monitoring results (hereinafter, referred to as "individual monitoring results") of each type of monitoring process. The diagnostic unit 1403 outputs a comprehensive diagnostic result based on the individual differential diagnostic results.

(4) Processing by the notification section

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, and the like, in the same manner as in the first example.

[ 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 7. Hereinafter, the same reference numerals are given to the same or corresponding components as or to the first and second examples (hereinafter, referred to as "first example and the like"), and the description will be given centering on the differences from the first example and the like. Therefore, the description of the same or corresponding contents as or to the first example and the like may be abbreviated or omitted.

< overview of 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.

In this example, as in the case of the first example and the like, the motor abnormality diagnosis system 1 includes the power conversion device 100 and the terminal device 200. In this example, unlike the case of the first example and the like, the motor abnormality diagnosis system 1 includes the server device 400.

The server device 400 (an example of an external device) is communicably connected to the power conversion device 100 via a predetermined communication line. The server device 400 is, for example, an on-premise (on-premise) server or a cloud server provided outside a factory where production equipment, mechanical equipment, and the like driven by the motor M are installed. The server apparatus 400 may be, for example, an edge server installed inside a factory or in a relatively close place to the factory.

The server apparatus 400 receives data of the monitoring result of the state relating to the electrical deterioration abnormality of the motor M from the power conversion apparatus 100, and accumulates the data in the internal nonvolatile storage device.

The server apparatus 400 monitors the change point of the history data corresponding to the deterioration abnormality (interlayer short circuit) of the motor M by analyzing the accumulated history data of the monitoring results in time series. Then, the server apparatus 400 transmits data including the monitoring result (for example, the presence or absence of the change point) to the power conversion apparatus 100. Thus, the power conversion apparatus 100 can perform diagnosis regarding the electrical deterioration abnormality of the motor M in consideration of the history data accumulated in the server apparatus 400.

< functional configuration of Power conversion device >

Fig. 7 is a functional block diagram showing a third example of the configuration of the power conversion apparatus 100 (control apparatus 140) according to the present embodiment.

As shown in fig. 7, the control device 140 includes a motor control unit 1401, a monitoring unit 1402, a diagnosis unit 1403, and a notification unit 1404, as in the case of the first example and the like.

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

The server apparatus 400 receives a signal including a monitoring result from the power conversion apparatus 100, and then analyzes a change point of the history data of the monitoring result based on the history data of the monitoring result composed of the latest monitoring result included in the signal and the past monitoring result accumulated inside. For example, the server apparatus 400 attempts to monitor the change points of the history data of the monitoring results by detecting the change points of the history data of each individual monitoring result using a method of multivariate analysis.

After the end of the monitoring process, the server apparatus 400 transmits a signal including the monitoring result (the presence or absence of a change point in the history data, the elapsed time from the change point, and the like of each individual monitoring result) (hereinafter, referred to as "history monitoring result") to the power conversion apparatus 100 through a predetermined communication line. Thus, the power conversion apparatus 100 (control apparatus 140) can acquire the history monitoring result including the information on the change point in the time series of the history data of the monitoring result by the monitoring unit 1402 from the server apparatus 400.

In the present example, the diagnosis unit 1403 diagnoses the electrical deterioration abnormality of the motor M based on the history monitoring result including the information on the change point of the history data of the monitoring result of the monitoring unit 1402 received from the server apparatus 400 in addition to the monitoring result from the monitoring unit 1402.

As in the case of the first example, the monitoring unit 1402 may monitor the specific harmonic component of the current or 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 case of the first example, the monitoring unit 1402 monitors the 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.

(3) Processing by a diagnostic section

The diagnosis unit 1403 diagnoses the electrical deterioration abnormality of the motor M, taking into account not only the latest monitoring result of the monitoring unit 1402 but also the history monitoring result received from the server apparatus 400 and including the information on the change point of the history data of the monitoring result of the monitoring unit 1402.

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 diagnostic unit 1403 may correct the diagnostic result based on the latest monitoring result of the monitoring unit 1402 based on the elapsed time from the change point or the like. Specifically, the diagnosis unit 1403 may add or multiply a predetermined value such as an elapsed time from the change point to or by a numerical value (0 to 1) indicating the presence or absence of the deterioration abnormality of the motor M, which is equivalent to a diagnosis result based on the latest monitoring result of the monitoring unit 1402. Similarly, the diagnostic unit 1403 may add or multiply a predetermined value such as an elapsed time from the change point to or by the value of the degree of deterioration abnormality of the motor M corresponding to the diagnostic result based on the latest monitoring result of the monitoring unit 1402. The predetermined value may be set to be variable so as to increase as the elapsed time from the change point increases (increases). This is because it is considered that the deterioration abnormality of the motor M progresses as the elapsed time from the change point increases (increases). Thus, the control device 140 can perform diagnosis regarding the deterioration abnormality of the motor M by considering not only the current electrical state of the motor M based on the latest monitoring result but also the tendency of the change in the electrical state of the motor M based on the history data of the past monitoring result. Therefore, control device 140 can improve the accuracy of diagnosis regarding the deterioration abnormality of motor M.

(4) Processing by the notification section

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 by the same method as in the case of the first example or the like.

[ other embodiments ]

Next, other embodiments will be explained.

The contents of the above embodiments may be modified or changed as appropriate.

For example, in the above embodiment, the second example (fig. 4 and 5) and the third example (fig. 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, the server apparatus 400 may be added, and the monitoring results of the monitoring unit 1402 including the monitoring results (individual monitoring results) of the unbalance monitoring process of (2-4) described above may be accumulated in the server apparatus 400. The diagnosis unit 1403 may perform diagnosis regarding the electrical deterioration abnormality of the motor M in consideration of the history monitoring result including the information on the change point of the history data of the monitoring result of the monitoring unit 1402 received from the server apparatus 400 in addition to the latest monitoring result of the monitoring unit 1402.

For example, in the above-described embodiment and the modification thereof, the power conversion device 100 may generate three-phase ac power for driving the motor M based on three-phase ac power input from a power source other than the commercial power source.

For example, in the above-described embodiment and the modification examples thereof, the power conversion device 100 may generate the three-phase alternating current for driving the motor M based on the power input from the dc power supply, instead of the power input from the three-phase alternating current based power supply, or in addition to the power input from the three-phase alternating current based power supply. In this case, the direct current is input to a direct current link portion (a positive line PL and a negative line NL) between the rectifier circuit 110 and the inverter circuit 130.

For example, in the above-described embodiment and the modified examples thereof, the display device 160 may be provided outside the casing of the power conversion device 100, for example, on the surface (outer surface) of the casing of a production facility, a mechanical facility, or the like, which is electrically driven by the motor M.

For example, in the above-described embodiment and the modified examples thereof, the function of the communication device 170 may be incorporated in the control device 140 (interface device).

In addition, for example, in the above-described embodiment and the modified examples thereof, the server apparatus 400 may be replaced with a host controller for managing field devices including the power conversion apparatus 100 of a plant installed in a production facility, a mechanical facility, or the like driven by the motor M. The upper controller is, for example, an edge controller.

For example, in the above-described embodiment and the modified examples thereof, a part or all of the functions of the control device 140 may be transferred to an external device of the power conversion device 100, for example, the terminal device 200, the server device 400, a higher controller (which are examples of information processing devices), and the like. Specifically, the functions of the monitoring unit 1402, the diagnosis unit 1403, and the notification unit 1404, which correspond to the diagnosis function regarding the electrical deterioration abnormality of the motor M, may be handed over to the terminal apparatus 200, the server apparatus 400, the upper controller, and the like.

For example, in the above-described embodiment and the modified examples thereof, a part or all of the functions of the control device 140 may be transferred to another control device mounted in the power conversion device 100. That is, the functions of the control device 140 may be implemented by a plurality of control devices provided in the power converter 100 in a distributed manner. For example, the function of driving the motor M by the inverter circuit 130 and the function of performing diagnosis regarding deterioration abnormality of the motor M may be realized by different control devices of the power conversion device 100.

For example, in the above-described embodiment and the modified examples thereof, the power conversion device 100 may be omitted, and the motor M may be directly driven by ac power supplied from the commercial power supply PS (an example of a power supply). In this case, a diagnostic function relating to an abnormality in deterioration of the motor M may be mounted on the circuit breaker BK (an example of the power transmission device). Specifically, the control device built in the circuit breaker BK may realize the same functions as the monitoring unit 1402, the diagnosis unit 1403, and the notification unit 1404 described above based on sensors (e.g., a current sensor for detecting a phase current, a voltage sensor for detecting a phase voltage, and the like) built in the circuit breaker BK.

[ Effect ]

Next, the operation of the motor abnormality diagnosis system 1 of the present embodiment will be described.

For example, in patent document 1, in order to determine an electrical deterioration abnormality, a dedicated device such as a phase current detector or a zero-phase current detector needs to be additionally provided. Therefore, there is a possibility that the configuration for determining the electrical deterioration abnormality of the motor M becomes complicated.

Further, for example, by monitoring the discharge state of the coil of the motor M, it is possible to diagnose the occurrence of the inter-layer short circuit of the motor M, but as described above, in the case where the motor M is a low-voltage motor, the occurrence of the inter-layer short circuit can be detected only in the final stage of the occurrence of the arc discharge.

In contrast, in the present embodiment, the power conversion apparatus 100 includes the inverter circuit 130, the sensor 150, the monitoring unit 1402, and the diagnosis unit 1403. Specifically, the inverter circuit 130 drives the motor M using electric 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 the voltage of the motor M and an unbalance state of at least one of the phase current and the 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 a d-axis current and a q-axis current of the motor M and a d-axis voltage and a q-axis voltage of the motor M based on the output of the sensor 150. Further, the monitoring unit 1402 may monitor the active power and the reactive power of the motor M based on the output of the sensor 150. The diagnosis unit 1403 performs diagnosis regarding an electrical deterioration abnormality of the motor M based on the monitoring result of the monitoring unit 1402.

Thus, the power conversion device 100 can perform diagnosis regarding the electrical deterioration abnormality of the motor M using the detection data of the built-in sensor 150. Therefore, it is not necessary to provide a dedicated sensor or the like for diagnosing the deterioration abnormality of the motor M outside the power conversion device 100, and the power conversion device 100 can diagnose the deterioration abnormality of the motor M with a simpler configuration. Further, power conversion device 100 can detect a change in the electrical state due to, for example, the occurrence of an interlayer short circuit by monitoring the electrical state of motor M such as the current and voltage harmonic components of motor M, the phase current of motor M, and imbalance (imbalance) in the phase voltages. Therefore, even when the motor M is a low-voltage motor, the power conversion device 100 can detect the electrical degradation abnormality (interlayer short circuit) at a relatively early stage after the occurrence of the electrical degradation abnormality.

In addition, in the present embodiment, power conversion apparatus 100 may include motor control unit 1401. Specifically, the motor control unit 1401 may control the inverter circuit 130 based on the output of the sensor 150, and may perform drive control for driving the motor M by the inverter circuit 130.

Accordingly, the power conversion device 100 can perform diagnosis regarding the electrical deterioration abnormality of the motor M by using the sensor 150 used for driving control of the motor M as well. Therefore, the power conversion device 100 can specifically perform diagnosis regarding the deterioration abnormality of the motor M with a simpler configuration.

In the present embodiment, the predetermined harmonic component may include at least one of a fifth harmonic component and a seventh harmonic component.

Thus, the power conversion device 100 can monitor the fifth harmonic component and the seventh harmonic component of the current and the voltage of the motor M, and can specifically diagnose an electrical deterioration abnormality (interlayer short circuit) of the motor M.

In the present embodiment, the monitoring unit 1402 may monitor the imbalance state of at least one of the phase current and the phase voltage of 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 based on comparison of at least one of the phase current and the phase voltage of the 3-phase, monitoring of the reverse phase component of at least one of the phase current and the phase voltage, and monitoring of the active power and the reactive power of the motor M, based on the output of the sensor 150.

Thus, the power converter 100 can monitor the imbalance state of the phase current and the phase voltage of the motor M. Further, the power converter 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.

In the present embodiment, motor control unit 1401 may perform drive control based on the output of sensor 150 and detection data (for example, detection data of sensor 300) relating to the operating state of motor M input from the outside of the power conversion apparatus. The imbalance state monitoring processes may include monitoring of the operating state of the motor M based on detection data input from the outside.

Thus, for example, when the vector control of the motor M is performed using detection data relating to the operating state (e.g., the rotational speed) of the motor M input from the outside, the power converter 100 can use the detection data as well as the monitoring of the unbalanced state of the phase current of the motor M. Therefore, the power conversion device 100 can more appropriately perform diagnosis regarding the electrical deterioration abnormality of the motor M with the existing configuration.

In the present embodiment, the monitoring unit 1402 may perform at least two or more types of monitoring processing among the specific harmonic wave monitoring processing and the plurality of imbalance state monitoring processing.

Thus, the power conversion device 100 can perform diagnosis regarding electrical deterioration abnormality (interlayer short circuit) of the motor M by using the result of two or more kinds of monitoring processes. Therefore, the power conversion device 100 can more appropriately perform diagnosis relating to the electrical deterioration abnormality of the motor M.

In addition, in the present embodiment, the power conversion apparatus 100 may include a communication apparatus 170. Specifically, the communication device 170 may transmit the monitoring result of the monitoring unit 1402 to the server device 400. The diagnosis unit 1403 may perform diagnosis regarding the electrical deterioration abnormality of the motor M based on the history of the monitoring results of the monitoring unit 1402 accumulated in the server apparatus 400.

This enables power conversion apparatus 100 to use the history of the past monitoring results. Therefore, the power conversion device 100 can more appropriately perform diagnosis relating to the electrical deterioration abnormality of the motor M.

In the present embodiment, the diagnosis unit 1403 may perform a diagnosis regarding an electrical deterioration abnormality of the motor M by capturing an elapsed time change based on a history of the monitoring result of the monitoring unit 1402.

Thus, the power conversion device 100 can specifically perform a diagnosis regarding the electrical deterioration abnormality of the motor M using the history of the past monitoring results.

In the present embodiment, the motor M can be directly driven by the three-phase ac power input from the commercial power supply PS, and the power conversion device 100 is omitted. In this case, the circuit breaker BK provided on the alternating-current transmission path between the commercial power source PS and the motor M may include the same functions as the sensor 150, the monitoring section 1402, and the diagnosis section 1403 of the power conversion apparatus 100. That is, the sensor of the breaker BK can detect the phase current of the electric circuit between the commercial power source PS and the motor M. 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 the voltage of the motor M and an imbalance state of at least one of the phase current and the phase voltage of the circuit between the inverter circuit 130 and the motor M, based on the output of the sensor 150. The diagnosis unit of the circuit breaker BK may perform diagnosis regarding an electrical deterioration abnormality of the motor M based on the monitoring result of the monitoring unit.

Thus, as in the case of the power conversion device 100 described above, the circuit breaker BK can diagnose the deterioration abnormality of the motor M with a simpler configuration. As in the case of the power conversion apparatus 100 described above, the circuit breaker BK can detect an electrical deterioration abnormality (interlayer short circuit) relatively early after the occurrence of the electrical deterioration abnormality, even in the case where the motor M is a low-voltage motor.

In the present embodiment, the functions of the monitoring unit 1402 and the diagnosis unit 1403 of the power conversion apparatus 100 (the control apparatus 140) can be transferred to an information processing apparatus outside the power conversion apparatus 100 such as the terminal apparatus 200, the server apparatus 400, and the host controller. Specifically, the monitoring unit of the information processing apparatus may acquire the output of the sensor 150 from the power conversion apparatus 100, and monitor at least one of a predetermined harmonic component of at least one of the current and the voltage of the motor M and an imbalance state of at least one of the phase current and the phase voltage of the circuit between the inverter circuit 130 and the motor M, based on the output of the sensor 150. The diagnostic unit of the information processing device may perform a diagnosis regarding the electrical deterioration abnormality of the motor M based on the monitoring result of the monitoring unit.

Thus, the information processing device can perform diagnosis regarding the deterioration abnormality of the motor M with a simpler configuration, as in the case of the power conversion device 100 and the like described above. As in the case of the power conversion device 100 and the like described above, the information processing device can detect an electrical deterioration abnormality (interlayer short circuit) relatively early after the occurrence of the electrical deterioration abnormality, even in the case where the motor M is a low-voltage motor.

Although the embodiments have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the gist of the claims.

Description of the reference numerals

1 Motor abnormality diagnosis system

100 power conversion device

110 rectification circuit

120 smoothing circuit

130 inverter circuit (driving part)

140 control device (information processing device)

150 sensor (Current detecting part)

160 display device

170 communication device

200 terminal device (information processing device)

210 display part

300 sensor

400 Server device (information processing device)

1401 Motor control part (control part)

1402 monitoring unit

1403 diagnostic part

1404 notification unit

BK breaker (electric power transmission device)

M Motor (AC motor)

NL negative electrode line

PL positive line

PS commercial power supply (Power supply)

Claims

1. A power conversion device comprising:

a drive unit that drives the ac motor using power input from the outside;

2. The power conversion apparatus according to claim 1,

the electric power steering apparatus further includes a control unit that controls the drive unit based on an output of the current detection unit to perform drive control for causing the drive unit to drive the ac motor.

3. The power conversion apparatus according to claim 2,

the predetermined harmonic component includes at least one of a fifth harmonic component and a seventh harmonic component.

4. The power conversion apparatus according to claim 2 or 3,

the monitoring unit monitors an unbalanced state of at least one of a phase current and a phase voltage of the circuit by performing at least one of a plurality of unbalanced state monitoring processes including monitoring based on a comparison of at least one of a phase current and a phase voltage of the circuit of a plurality of phases, monitoring of an opposite phase component of at least one of a phase current and a phase voltage of the circuit, and monitoring of active power and reactive power of the ac motor, based on an output of the current detecting unit.

5. The power conversion apparatus according to claim 4,

the control unit performs the drive control based on the output of the current detection unit and detection data relating to the operating state of the ac motor input from the outside of the power conversion device,

the plurality of imbalance state monitoring processes include monitoring an operation state of the ac motor based on detection data.

6. The power conversion apparatus according to claim 5,

the monitoring unit performs at least two or more types of monitoring processing among the predetermined harmonic component monitoring processing and the plurality of imbalance state monitoring processing.

7. The power conversion apparatus according to any one of claims 1 to 6,

further comprises a transmission unit for transmitting the monitoring result of the monitoring unit to a predetermined external device,

the diagnostic unit diagnoses an electrical deterioration abnormality of the ac motor based on a history of monitoring results of the monitoring unit accumulated in the external device.

8. The power conversion apparatus according to claim 7,

the diagnosis unit captures a temporal change based on a history of a monitoring result of the monitoring unit, and thereby performs a diagnosis regarding an electrical deterioration abnormality of the ac motor.

9. A power conversion device comprising:

a drive unit that drives the ac motor using power input from the outside;

10. A power conversion device comprising:

a drive unit that drives the ac motor using power input from the outside;

11. A power transmission device provided on an alternating-current transmission path between a power source and an alternating-current motor, the power transmission device comprising:

12. An information processing apparatus comprising:

13. A deterioration abnormality diagnosis method executed by an information processing apparatus that is built in or can acquire an output of a current detection unit from a power conversion apparatus including a drive unit that drives an alternating-current motor using power input from outside and a current detection unit that detects a phase current of a circuit between the drive unit and the alternating-current motor, the deterioration abnormality diagnosis method comprising: