Power conversion device, diagnosis device, and diagnosis method

Abstract

Provided is a power conversion device, a diagnosis device, and a diagnosis method that can more appropriately perform diagnosis related to a deterioration abnormality of an AC motor. A power conversion device (100) of one embodiment includes an inverter circuit (130) that drives an AC motor using power input from the outside, a sensor (150) that detects a phase current of the motor (M), a power calculation unit (1402) that calculates at least one of active power and reactive power of the motor (M) on the basis of an output of the sensor (150), and a diagnosis unit (1405) that performs diagnosis related to a deterioration abnormality of the motor (M) on the basis of a frequency component of at least one of the active power and the reactive power.

Description

Technical Field

[0001] This invention relates to power conversion devices, etc. Background Technology

[0002] For example, there are known techniques for diagnosing AC motor deterioration anomalies based on the active and reactive power of the AC motor (see Patent Documents 1 and 2).

[0003] <Prior art documents>

[0004] <Patent Documents>

[0005] Patent Document 1: Japanese Patent No. 6777251

[0006] Patent Document 2: Japanese Patent No. 6818155 Summary of the Invention

[0007] <Problem to be solved by the invention>

[0008] However, the aforementioned literature focuses on diagnosing AC motor degradation anomalies based solely on the magnitude of the active and reactive power. Therefore, for example, there is a possibility of misdiagnosing degradation anomalies by focusing on instantaneous changes in the active and reactive power of the AC motor. Furthermore, there is a possibility that diagnoses related to degradation anomalies that are not manifested in the magnitude of the AC motor's active and reactive power may not be possible. Consequently, there is a possibility that diagnoses related to AC motor degradation anomalies may not be properly performed.

[0009] Therefore, in view of the above problems, the object of the present invention is to provide a technique that can more appropriately diagnose abnormalities related to the deterioration of AC motors.

[0010] <Methods for solving problems>

[0011] To achieve the above objectives, in one embodiment of the present invention, a power conversion device is provided, comprising:

[0012] The drive unit uses externally input electricity to drive the AC motor;

[0013] The current detection unit detects the phase current of the aforementioned AC motor.

[0014] The calculation unit, based on the output of the current detection unit, calculates at least one of the active power and reactive power of the AC motor; and

[0015] The diagnostic unit performs diagnoses related to the deterioration anomalies of the AC motor based on the frequency components of at least one of the active power and the reactive power.

[0016] In another embodiment of the present invention, a diagnostic device is provided, comprising:

[0017] The arithmetic unit acquires the output of the current detection unit that detects the phase current of the AC motor, and calculates at least one of the active power and reactive power of the AC motor; and

[0018] The diagnostic unit performs diagnoses related to the deterioration anomalies of the AC motor based on the frequency components of at least one of the active power and the reactive power.

[0019] In another further embodiment of the present invention, a diagnostic method is provided, comprising:

[0020] In the calculation step, the diagnostic device acquires the output of a current detection unit that detects the phase current of the AC motor, and calculates at least one of the active power and reactive power of the AC motor based on the output of the current detection unit; and

[0021] The diagnostic step involves the diagnostic device performing a diagnosis related to the deterioration anomaly of the AC motor based on the frequency component of at least one of the active power and the reactive power.

[0022] <The Effects of the Invention>

[0023] According to the above implementation method, it is possible to more appropriately diagnose abnormalities related to the deterioration of AC motors. Attached Figure Description

[0024] Figure 1 This is a diagram illustrating an example of the configuration of a degradation anomaly diagnostic system.

[0025] Figure 2 This is a functional block diagram illustrating an example of the functional configuration of a power conversion device (control device).

[0026] Figure 3 This is a functional block diagram illustrating an example of active and reactive power calculations performed by the power calculation unit.

[0027] Figure 4 It is a graph that shows the amplitude of instantaneous active power and instantaneous reactive power of a motor in a normal state using a time series.

[0028] Figure 5It is a graph showing the amplitude of instantaneous active power and instantaneous reactive power of a motor in a time series, illustrating the relative development of the degradation anomaly.

[0029] Figure 6 This is a diagram illustrating an example of the results of frequency analysis of the instantaneous active and reactive power of an electric motor.

[0030] Figure 7 This is a diagram showing an example of the structure of the analysis unit.

[0031] Figure 8 This is a figure illustrating an example of a diagnostic method for degradation anomalies based on the results of frequency analysis.

[0032] Figure 9 This is a flowchart that roughly illustrates an example of a diagnostic process for motor deterioration.

[0033] Figure 10 This is a functional block diagram illustrating another example of the functional configuration of a power conversion device (control device).

[0034] Figure 11 This is a graph representing an example of the amplitude analysis results of the instantaneous active power and instantaneous reactive power of an electric motor.

[0035] Figure 12 This is a figure illustrating an example of a diagnostic method for degradation anomalies based on amplitude analysis results.

[0036] Figure 13 This is another example of a diagnostic method for degradation anomalies based on amplitude analysis results.

[0037] Figure 14 This is a flowchart that roughly illustrates another example of the diagnostic and handling process for motor deterioration anomalies.

[0038] Explanation of reference numerals in the attached figures

[0039] 1. Deterioration Anomaly Diagnosis System

[0040] 100 Power conversion device

[0041] 110 Rectifier Circuit

[0042] 120 smoothing circuit

[0043] 130 Inverter Circuit (Drive Section)

[0044] 140 Control device (diagnostic device)

[0045] 150 Sensor (Current Detection Unit)

[0046] 160 display device

[0047] 170 Communication devices

[0048] 200 sensors

[0049] 300 Management Device (Diagnostic Device)

[0050] 310 Display Section

[0051] 400 Terminal Device (Diagnostic Device)

[0052] 410 Display Section

[0053] 1401 Motor Control Unit

[0054] 1402 Power Computing Department (Computing Department)

[0055] 1403 Analysis Department

[0056] 1403A Frequency Analysis Section

[0057] 1403B Amplitude Analysis Department

[0058] 1404, 1404A, 1404B Feature quantity acquisition section (acquisition section)

[0059] 1405 Diagnostic Department

[0060] 1406 Notification Department

[0061] BK circuit breaker

[0062] M motor (AC motor)

[0063] NL negative line

[0064] PL positive line

[0065] PS Commercial Power Supply (Power Supply) Detailed Implementation

[0066] The embodiments will now be described with reference to the accompanying drawings.

[0067] [Overview of the Deterioration Anomaly Diagnosis System]

[0068] First, refer to Figure 1 The general outline of the degradation anomaly diagnosis system 1 of this embodiment will be described.

[0069] Figure 1 This is a diagram showing a first example of the configuration of the degradation anomaly diagnosis system 1 of this embodiment.

[0070] The deterioration anomaly diagnosis system 1 performs diagnoses related to the deterioration anomalies of the motor M.

[0071] Diagnostic methods related to the deterioration of motor M include, for example, diagnosing the presence or absence of deterioration in motor M, and diagnosing (estimating) the degree of deterioration development of motor M. The degree of deterioration development of motor M can be represented by multiple stages (levels), or by continuously changing numerical values.

[0072] Deterioration of the motor M includes, for example, insulation degradation of the windings (coils). Insulation degradation refers to the deterioration of the insulation of the windings of the motor M caused by at least one of thermal, electrical, mechanical, or environmental factors. If insulation degradation progresses, for example, the resistance value of the winding changes in the deteriorated portion, resulting in winding imbalance and current imbalance. Ultimately, this leads to a phase short circuit in the winding, causing mechanical failure of the motor M.

[0073] In contrast, the degradation anomaly diagnosis system 1, by performing diagnoses related to degradation anomalies, including insulation degradation of the motor M, enables the user to grasp the presence and extent of degradation anomalies in the motor M. Therefore, for example, the user can anticipate signs of mechanical failure in the motor M. Consequently, the degradation anomaly diagnosis system 1 reduces the frequency of maintenance for equipment including the motor M, allowing maintenance to be performed based on the condition of the motor M, and reducing the risks associated with sudden shutdowns of equipment including the motor M, and prolonged downtime of equipment undergoing restoration work.

[0074] like Figure 1 As shown, the deterioration anomaly diagnosis system 1 includes a power conversion device 100, a sensor 200, a management device 300, and a terminal device 400.

[0075] The power conversion device 100, management device 300, and terminal device 400 included in the deterioration anomaly diagnosis system 1 can be one or more.

[0076] The power conversion device 100 converts three-phase AC power (e.g., R phase, S phase, and T phase) input from a commercial power source PS into three-phase AC power (e.g., U phase, V phase, and W phase) with a specified voltage and a specified frequency, thereby driving the motor M.

[0077] It should be noted that the power conversion device 100 can generate three-phase AC power for driving the motor M based on three-phase AC power input from a power source different from the commercial power supply PS. Alternatively, the power conversion device 100 can generate three-phase AC power for driving the motor M based on power input from a DC power source, in addition to power input from a three-phase AC power source. In this case, the DC link (positive line PL and negative line NL) between the DC power input rectifier circuit 110 and the inverter circuit 130 is used.

[0078] In the AC transmission path (R-phase, S-phase, and T-phase wires) between the commercial power supply PS and the power conversion device 100, a circuit breaker BK capable of switching the connection and disconnection states of the AC transmission path is installed. The circuit breaker BK is, for example, an MCCB (Molded Case Circuit Breaker).

[0079] The electric motor M (an example of an AC motor) uses three-phase AC power output from the power conversion device 100 to electrically drive specified equipment installed in specified machinery, factories, buildings, etc. Specified machinery includes, for example, compressors, fans, blowers, etc. Specified equipment includes, for example, conveyor systems such as elevators and conveyor belts.

[0080] like Figure 1 As shown, the power conversion device 100 includes a rectifier circuit 110, a smoothing circuit 120, an inverter circuit 130, a control device 140, a sensor 150, a display device 160, and a communication device 170.

[0081] The rectifier circuit 110 is configured to rectify the three-phase AC power input from the commercial power supply PS (R-phase, S-phase, and T-phase) to output DC power. The positive and negative output terminals of the rectifier circuit 110 are connected to one end of the positive line PL and the negative line NL, respectively, and the DC power is output to the smoothing circuit 120 via the positive and negative lines PL and NL. The rectifier circuit 110 includes, for example, six semiconductor diodes, forming a bridge full-wave rectifier circuit with three sets of series-connected semiconductor diodes forming the upper and lower bridge arms connected in parallel.

[0082] The smoothing circuit 120 suppresses the pulsation of the DC power output from the self-rectifier circuit 110 and the DC power regenerated by the self-inverter circuit 130, thus smoothing them out.

[0083] The smoothing circuit 120 includes, for example, a smoothing capacitor.

[0084] The smoothing capacitor can be connected in parallel with the rectifier circuit 110 and the inverter circuit 130 in the path connecting the positive line PL and the negative line NL.

[0085] The smoothing capacitor, through appropriate repeated charging and discharging, smooths the DC power output from the self-rectifier circuit 110 and the DC power output (regenerated) from the self-inverter circuit 130.

[0086] There can be one smoothing capacitor. Alternatively, multiple smoothing capacitors can be configured, connected in parallel or in series between the positive line PL and the negative line NL. Furthermore, multiple smoothing capacitors can be constructed by connecting two or more smoothing capacitors in series in parallel between the positive line PL and the negative line NL.

[0087] Additionally, the smoothing circuit 120 includes, for example, a reactor.

[0088] The reactor can be placed on the positive line PL between the rectifier circuit 110 and the smoothing capacitor (specifically, at the branch point of the path where the smoothing capacitor is located).

[0089] The reactor appropriately generates voltage in a way that hinders changes in current, while smoothing the DC output from the self-rectifier circuit 110 and the DC output (regenerated) from the self-inverter circuit 130.

[0090] The positive and negative input terminals of the inverter circuit 130 (an example of a drive unit) are connected to the other ends of the positive line PL and the negative line NL. The inverter circuit 130 converts the direct current supplied by the self-smoothing circuit 120 into three-phase alternating current (e.g., U-phase, V-phase, and W-phase) with a predetermined frequency and voltage through the switching operation of a semiconductor switch, and outputs it to the motor M, thereby driving the motor M. The semiconductor switch can be, for example, a silicon (Si) IGBT (Insulated Gate Bipolar Transistor) or MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). Alternatively, the semiconductor switch can be a semiconductor element using a wide-bandgap semiconductor such as silicon carbide (SiC) or gallium nitride (GaN).

[0091] The inverter circuit 130 is configured with a bridge circuit, which includes, for example, six semiconductor switches. Three sets of series-connected bodies (switch legs) of two semiconductor switches forming the upper and lower bridge arms are connected in parallel between the positive line PL and the negative line NL. Furthermore, the inverter circuit 130 can output three-phase AC power via the U-phase, V-phase, and W-phase lines drawn from the connection points of the three sets of upper and lower bridge arms. Additionally, return diodes can be connected in parallel with each of the six semiconductor switches.

[0092] The control device 140 (an example of a diagnostic device) performs control related to the power conversion device 100.

[0093] The functions of the control device 140 can be implemented using any hardware or any combination of hardware and software. For example, the control device 140 is centered around a computer that includes a storage device such as a CPU (Central Processing Unit), RAM (Random Access Memory), a non-volatile auxiliary storage device such as ROM (Read Only Memory), and an interface device for external input / output. The control device 140 implements various functions by loading programs installed in the auxiliary storage device into the memory device and executing them with the CPU. Furthermore, the control device 140 receives external signals or outputs (transmits) signals to the outside via the interface device.

[0094] Control device 140 outputs drive signals to inverter circuit 130 (specifically, the gates of each semiconductor switch), and drives inverter circuit 130 to ensure that motor M meets specified operating conditions. In other words, control device 140 generates control signals for driving motor M according to specified operating conditions and outputs them to inverter circuit 130.

[0095] In addition, the control device 140 performs diagnostics, for example, related to abnormal deterioration of the motor M. Details will be described later.

[0096] Furthermore, the functions of control device 140 can be implemented by distributing them among multiple control devices (control circuits). For example, the function of driving motor M via inverter circuit 130 and the function of diagnosing abnormalities related to motor M deterioration can be implemented by different control devices of power conversion device 100. Additionally, some or all of the functions of control device 140 can be transferred to external devices of power conversion device 100, such as management device 300 and terminal device 400 (both examples of diagnostic devices). For example, some or all of the diagnostic functions related to abnormalities in motor M deterioration can be transferred to management device 300, terminal device 400, etc.

[0097] Sensor 150 is used to acquire detection data related to the state of power conversion device 100. Sensor 150 is connected to control device 140, for example, via a one-to-one communication line, and a signal corresponding to the detection data (hereinafter referred to as "detection signal") is introduced into control device 140. Thus, control device 140 can perform control related to power conversion device 100 based on the detection signal from sensor 150.

[0098] Sensor 150 may include, for example, a voltage sensor for detecting the link voltage between the positive line PL and the negative line NL. Additionally, sensor 150 (an example of a current detection unit) may include, for example, a current sensor for detecting the phase currents (hereinafter referred to as "U-phase current", "V-phase current", and "W-phase current") of the circuit between the inverter circuit 130 and the motor M, i.e., the U-phase line, V-phase line, and W-phase line. The current sensor may use, for example, a Hall effect sensor, a shunt resistor, a fluxgate magnetometer, etc., to detect the phase current of the motor M, and uses an AD (Analog-Digital) converter to output the detected value (digital value) of the phase current. Furthermore, sensor 150 may include a voltage sensor for detecting the 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, V-phase line, and W-phase line.

[0099] The display device 160 is provided, for example, on the outer surface of the housing of the power conversion device 100. Under the control of the control device 140, the display device 160 displays information related to the status of the power conversion device 100.

[0100] It should be noted that the display device 160 can be located outside the housing of the power conversion device 100, for example, on the surface (outer surface) of the housing of production equipment, machinery, etc., which are electrically driven by the motor M.

[0101] The communication device 170 communicates with external machines of the power conversion device 100, such as the management device 300 and the terminal device 400, via a prescribed communication line.

[0102] The specified communication line can be, for example, a one-to-one communication line. Additionally, the specified communication line can include, for example, a local area network (LAN) such as a field network built within a facility (factory) equipped with production equipment or machinery driven by an electric motor M. The local area network can be built via wired or wireless means, or both. Furthermore, the specified communication line can include, for example, an external wide area network (WAN) of the facility (factory) equipped with production equipment or machinery driven by an electric motor M. The wide area network can include, for example, a mobile communication network with a base station as the endpoint, a satellite communication network utilizing communication satellites, the Internet, etc. Additionally, the specified communication line can include, for example, a short-range communication line based on a specified wireless communication standard such as Bluetooth (registered trademark), WiFi, etc.

[0103] It should be noted that the communication device 170 can be built into the control device 140 as an interface with external machines.

[0104] Sensor 200 is located outside the power conversion device 100 and is used to output detection data related to the state of the motor M. Sensor 200 is, for example, a rotary position sensor capable of detecting the rotational position and rotational speed of the motor M. The rotary position sensor can be, for example, an encoder. The encoder can detect the rotational position and rotational speed of the motor M in any way, such as optical or magnetic. The output (detection data) of sensor 200 is transmitted to the power conversion device 100 (control device 140) via a one-to-one communication line or the like.

[0105] It should be noted that the detection data of sensor 200 can be imported into control device 140 through communication device 170 instead of directly into control device 140 through the prescribed communication line.

[0106] The management device 300 is located outside the power conversion device 100 and acts as a host device for the power conversion device 100, managing (monitoring) both the power conversion device 100 and the motor M. For example, the management device 300 obtains data related to the status of the power conversion device 100 and the motor M from the power conversion device 100, thereby monitoring their status. Additionally, the management device 300 outputs control signals to the power conversion device 100, thereby controlling the power conversion device 100 and the motor M. Furthermore, the management device 300 provides information related to the power conversion device 100 and the motor M to users such as operators and managers through a display unit 310, or receives input from users and sends it to the power conversion device 100.

[0107] The management device 300 is, for example, an edge controller such as a PLC (Programmable Logic Controller) used to manage field devices including the power conversion device 100 in a factory or similar facility that houses specified machinery and equipment, including the electric motor M. Alternatively, the management device 300 may be a management terminal device. This terminal device can be, for example, a fixed computer terminal such as a desktop PC (Personal Computer) installed in an office in the factory or similar facility. Alternatively, it can be a portable terminal device (portable terminal) that can be carried by factory managers or operators, such as a tablet, smartphone, or laptop PC. Furthermore, the management device 300 may also be a server device. This server device can be, for example, a locally deployed server or cloud server remotely installed in a factory or similar facility housing specified machinery and equipment, including the electric motor M. Alternatively, the server device can be an edge server installed within the premises of the factory or similar facility housing specified machinery and equipment, including the electric motor M, or in a nearby facility.

[0108] Terminal device 400 is a user terminal located outside power conversion device 100 and used by the user of power conversion device 100 (deterioration and abnormality diagnosis system 1). Terminal device 400 provides the user with various information related to power conversion device 100 and motor M through display unit 410, or receives various inputs from the user and sends them to power conversion device 100.

[0109] Terminal device 400 can be a fixed terminal device such as a desktop PC. Alternatively, terminal device 400 can be a portable terminal device (portable terminal) such as a smartphone, tablet, or laptop PC.

[0110] [An example of the functional configuration of a power conversion device]

[0111] Next, refer to Figure 2 , Figure 3 An example of the functional configuration of the power conversion device 100 will be explained.

[0112] Figure 2 This is a functional block diagram illustrating an example of the functional configuration of the power conversion device 100 (control device 140) of this embodiment. Figure 3 This is a functional block diagram illustrating an example of the calculation and processing of instantaneous active power P and instantaneous reactive power Q performed by the power calculation unit 1402.

[0113] like Figure 2 As shown, the control device 140 includes a motor control unit 1401, a power calculation unit 1402, an analysis unit 1403, a feature acquisition unit 1404, a diagnostic unit 1405, and a notification unit 1406. Part or all of the functions of each of the motor control unit 1401, power calculation unit 1402, analysis unit 1403, feature acquisition unit 1404, diagnostic unit 1405, and notification unit 1406 are implemented, for example, by loading a program installed in an auxiliary storage device into a memory device and executing it via the CPU.

[0114] The motor control unit 1401 uses the inverter circuit 130 to drive and control the motor M. The motor control unit 1401 can drive and control the motor M using any control method, such as V / f control or vector control.

[0115] Specifically, the motor control unit 1401 generates a control signal (drive command) for driving the motor M under specified operating conditions based on the detection data of the sensor 150 (e.g., the detection values ​​of U-phase current, V-phase current, and W-phase current), and outputs it to the inverter circuit 130.

[0116] For example, the motor control unit 1401 generates command values ​​(hereinafter referred to as "voltage command values") for the U-phase voltage, V-phase voltage, and W-phase voltage based on the detection data of the sensor 150 and the operating conditions of the motor M, and outputs control signals corresponding to the voltage command values ​​to the inverter circuit 130.

[0117] The power calculation unit 1402 (an example of a calculation unit) calculates the instantaneous active power P and instantaneous reactive power Q of the motor M based on the detection data of the sensor 150.

[0118] For example, such as Figure 3 As shown, when the motor control unit 1401 employs vector control, the instantaneous active power P and instantaneous reactive power Q of the motor M are calculated using the calculation results from the processing related to vector control.

[0119] In this case, the motor control unit 1401 includes a three-phase to two-phase conversion unit 1401A, a rotary coordinate conversion unit 1401B, a speed regulation unit 1401C, a current command generation unit 1401D, a current regulation unit 1401E, a conversion unit 1401F, and a drive command output unit 1401G.

[0120] The three-phase to two-phase conversion unit 1401A converts the U-phase current Iu, V-phase current Iv, and W-phase current Iw detected by the sensor 150 (current sensor) into the α-axis current Iα and β-axis current Iβ of a two-phase fixed coordinate system (α-axis, β-axis) using known methods such as the Clark transformation.

[0121] It should be noted that the U-phase current Iu, V-phase current Iv, and W-phase current Iw can all be detected by sensor 150 (current sensor), or only the current of any two phases can be detected by sensor 150, and the current of the remaining phase can be estimated based on the other two detected values.

[0122] The rotating coordinate transformation unit 1401B converts the α-axis current Iα and β-axis current Iβ based on the output of the sensor 150 into the d-axis current Id and q-axis current Iq of the two-phase rotating coordinate system (d-axis, q-axis) on the motor M using known methods such as Park transformation.

[0123] The speed regulation unit 1401C adjusts the rotational speed of the motor M based on a command value (hereinafter referred to as "speed command") ω* of the angular velocity of the motor M based on the operating conditions of the motor M, and the angular velocity ω of the motor M detected by the sensor 200 (rotary position sensor). For example, the speed regulation unit 1401C generates and outputs a command value (hereinafter referred to as "torque command") τ* of the torque of the motor M so that the deviation between the actual angular velocity ω of the motor and the speed command ω* is close to zero. The speed regulation unit 1401C can generate the torque command τ* using any control method. For example, the speed regulation unit 1401C generates the torque command τ* using P (Proportional) control, PI (Proportional-Integral) control, PID (Proportional-Integral-Differential) control, etc.

[0124] It should be noted that the angular velocity ω can be estimated based on the phase current and phase voltage of the motor M, without relying on the output of sensor 200 (rotary position sensor). In this case, sensor 200 (rotary position sensor) is omitted.

[0125] The current command generation unit 1401D generates and outputs the command value (hereinafter referred to as "d-axis current command") Id* and the command value (hereinafter referred to as "q-axis current command") Iq* of the motor M to implement the torque command τ* based on the torque command τ*.

[0126] The current regulating unit 1401E regulates the current of the motor M based on the d-axis current command Id* and the q-axis current command Iq*, as well as the d-axis current Id and q-axis current Iq, which are equivalent to the actual detected values ​​of the motor M. For example, the current regulating unit 1401E generates and outputs command values ​​(hereinafter referred to as "d-axis voltage command") Vd* and command values ​​(hereinafter referred to as "q-axis voltage command") Vq* for the motor M, which bring the deviations between the d-axis current command Id* and the d-axis current Id, and the deviations between the q-axis current command Iq* and the q-axis current Iq, close to zero. The current regulating unit 1401E can generate the d-axis voltage command Vd* and the q-axis voltage command Vq* using any control method. For example, the speed regulating unit 1401C generates the d-axis voltage command Vd* and the q-axis voltage command Vq* using P control, PI control, PID control, etc.

[0127] The conversion unit 1401F converts the d-axis voltage command Vd* and the q-axis voltage command Vq* into the command values ​​of the U-phase voltage (hereinafter referred to as "U-phase voltage command") Vu*, the command value of the V-phase voltage (hereinafter referred to as "V-phase voltage command") Vv*, and the command value of the W-phase voltage (hereinafter referred to as "W-phase voltage command") Vw*.

[0128] The drive command output unit 1401G generates drive commands for the inverter circuit 130 based on the U-phase voltage command Vu*, V-phase voltage command Vv*, and W-phase voltage command Vw* of the motor M, and outputs them to the inverter circuit 130. Specifically, the drive command output unit 1401G generates gate drive commands for the semiconductor switches of the inverter circuit 130 and applies them to the gate terminals of the semiconductor switches of the inverter circuit 130. Therefore, the motor control unit 1401 can use the inverter circuit 130 to appropriately drive and control the motor M in accordance with predetermined operating conditions.

[0129] The power calculation unit 1402 can calculate the instantaneous active power P and instantaneous reactive power Q of the motor M based on the output of the rotating coordinate transformation unit 1401B (d-axis current Id, q-axis current Iq) and the output of the current regulation unit 1401E (d-axis voltage command Vd*, q-axis voltage command Vq*) according to the following formulas (1) and (2).

[0130] (Mathematical Formula 1)

[0131] P = Vd * ·Id+Vq * ·Iq…(1)

[0132] O=Vd * ·Iq-Vq * ·Id…(2)

[0133] It should be noted that, when using V / f control or similar methods, the U-phase voltage command Vu*, V-phase voltage command Vv*, and W-phase voltage command Vw* generated by the motor control unit 1401 can be coordinate-transformed accordingly with the rotation of the motor M, thereby generating the d-axis voltage command Vd* and the q-axis voltage command Vq*. Furthermore, the power calculation unit 1402 can use the current and voltage of a fixed coordinate system (α-axis, β-axis) instead of the current and voltage of the rotating coordinate system (d-axis, q-axis) to calculate the instantaneous active power P and instantaneous reactive power Q of the motor M.

[0134] Analysis unit 1403 performs an analysis relating to changes in instantaneous active power P and instantaneous reactive power Q, which indicate the development of abnormal degradation in motor M. Details will be described later (see reference). Figure 6 ).

[0135] The characteristic quantity acquisition unit 1404 (an example of an acquisition unit) acquires characteristic quantities related to the deterioration anomaly of the motor M based on the analysis results of the analysis unit 1403. Details will be described later (see [reference]). Figure 8 ).

[0136] The diagnostic unit 1405 performs diagnoses related to the deterioration anomalies of the motor M based on the feature quantities obtained by the feature quantity acquisition unit 1404. Details will be described later (see [reference]). Figure 8 ).

[0137] The notification unit 1406 notifies the user of the diagnostic results based on the diagnostic results from the diagnostic unit 1405. The notification unit 1406 may, for example, display information related to the diagnostic results on the display device 160. Alternatively, the notification unit 1406 may, for example, transmit a signal including information related to the diagnostic results to the management device 300 and the terminal device 400 via the communication device 170. Thus, the notification unit 1406 can display information related to the diagnostic results on the display unit 310 of the management device 300 and the display unit 410 of the terminal device 400, thereby notifying the user of the diagnostic results.

[0138] It should be noted that the management device 300 can, for example, summarize the diagnostic results related to the deterioration anomalies of multiple motors M under management and notify the user through the display unit 310. Furthermore, the management device 300 can, for example, formulate a maintenance plan based on the diagnostic results related to the deterioration anomalies of the multiple motors M under management. The same applies to the terminal device 400.

[0139] [An example of a diagnostic method related to abnormal deterioration of an electric motor]

[0140] Next, refer to Figures 4-8 An example of a diagnostic method related to abnormal deterioration of motor M will be illustrated.

[0141] Figure 4 This is a graph showing the amplitude of the instantaneous active power P and instantaneous reactive power Q of a motor M under normal conditions, presented as a time series. Specifically, Figure 4 The graph 401 shows the instantaneous active power P of the motor M in its normal state, and the graph 402 shows the time series of instantaneous reactive power Q. Figure 5 This is a graph showing the amplitudes of the instantaneous active power P and instantaneous reactive power Q of a motor M after the relative development of the degradation anomaly. Specifically, Figure 5 The graph 501 shows the instantaneous active power P of the motor M in the time series after the relative development of the deterioration anomaly, and the graph 502 shows the instantaneous reactive power Q in the time series. Figure 6This is a graph showing an example of the results of frequency analysis of the instantaneous active power P and instantaneous reactive power Q of motor M. Figure 7 This is a diagram showing an example of the configuration of the analysis unit 1403. Figure 8 This is a figure illustrating an example of a diagnostic method for degradation anomalies based on the results of frequency analysis.

[0142] like Figure 4 As shown, under normal conditions where the deterioration of motor M has not developed, the amplitudes of the instantaneous active power P and instantaneous reactive power Q of motor M are approximately constant.

[0143] On the other hand, such as Figure 5 As shown, when the abnormal degradation of motor M develops to a certain extent, vibration components sometimes appear in the amplitudes of the instantaneous active power P and instantaneous reactive power Q of motor M. This is because if motor M experiences abnormal degradation, frequency components larger than the fundamental frequency (typically, higher harmonic components) sometimes overlap on the waveforms of instantaneous active power P and instantaneous reactive power Q.

[0144] Therefore, in this example, the control device 140 focuses on the frequency components of the instantaneous active power P and the instantaneous reactive power Q to perform a diagnosis related to the deterioration anomaly of the motor M.

[0145] Specifically, the analysis unit 1403 performs analysis related to the frequency components of the instantaneous active power P and the instantaneous reactive power Q (hereinafter, for convenience, it is referred to as "frequency analysis").

[0146] For example, such as Figure 6 As shown, the analysis unit 1403 can perform spectrum analysis of instantaneous active power P and instantaneous reactive power Q using methods such as FFT (Fast Fourier Transform).

[0147] In this example ( Figure 6 In the specified frequency components (the area enclosed by the dashed line in the figure) which are larger than the fundamental frequency, there are very large spectral values ​​of vibrational components with amplitudes equivalent to instantaneous active power P and instantaneous reactive power Q.

[0148] Furthermore, for example, if the frequencies of the vibrational components generated in the amplitudes of the instantaneous active power P and the instantaneous reactive power Q are known in advance, the analysis unit 1403 may include a narrow-band bandpass filter corresponding to the frequency band containing that frequency. Furthermore, the analysis unit 1403 can use the narrow-band bandpass filter to extract a predetermined frequency component from the instantaneous active power P and the instantaneous reactive power Q.

[0149] The specified frequency components are, for example, higher harmonic components, i.e., frequency components that are integer multiples of the fundamental frequency. Furthermore, there can be multiple specified frequency components.

[0150] Additionally, for example, such as Figure 7 As shown, when the frequency of the vibration component generated in the amplitude of the instantaneous active power P and the instantaneous reactive power Q varies according to the rotational speed (angular velocity ω) of the motor M, a tracking filter TF may be included. Furthermore, the analysis unit 1403 can use the tracking filter TF to extract a predetermined frequency component related to the rotational frequency of the motor M from the instantaneous active power P and the instantaneous reactive power Q.

[0151] Specifically, the tracking filter TF can extract the rotational frequency component of the motor M from the instantaneous active power P and instantaneous reactive power Q through the rotating coordinate transformation unit TF1 and the low-pass filter unit TF2. This is because in a coordinate system rotating at the angular velocity ω of the motor M, the instantaneous active power P and instantaneous reactive power Q are equivalent to DC components. Furthermore, the tracking filter TF can output a predetermined frequency component related to the rotational frequency from the instantaneous active power P and instantaneous reactive power Q through the fixed coordinate transformation unit TF3.

[0152] Based on the frequency analysis results from the analysis unit 1403, the characteristic quantity acquisition unit 1404 acquires characteristic quantities (hereinafter referred to as "frequency characteristic quantities") focusing on the frequency components of instantaneous active power P and instantaneous reactive power Q.

[0153] For example, the characteristic quantity acquisition unit 1404 can acquire the magnitude (e.g., spectral value) of a specified frequency component of the instantaneous active power P and instantaneous reactive power Q as a frequency characteristic quantity. This is because it can be considered that the larger the magnitude of the specified frequency component, the more significant the vibration component of the amplitude of the instantaneous active power P and instantaneous reactive power Q, and the more relatively developed the degradation anomaly.

[0154] The diagnostic unit 1405 performs diagnoses related to the deterioration and abnormalities of the motor M based on frequency characteristic quantities.

[0155] For example, such as Figure 8 As shown, if the magnitude (spectral value) of the specified frequency components of the instantaneous active power P and instantaneous reactive power Q, which are frequency characteristic quantities, exceeds the specified reference (threshold Sp_th), the diagnostic unit 1405 diagnoses the possibility of abnormal deterioration of the motor M.

[0156] The specified reference (threshold Sp_th) can be a fixed value, or it can be a variable value that changes according to the operating state of the motor M. Furthermore, the specified reference (threshold Sp_th) can be the same or different in the case of instantaneous active power P and instantaneous reactive power Q.

[0157] In addition, for example, when there are multiple specified frequency components, if the sum of the magnitudes of the multiple specified frequency components exceeds a specified threshold, it can be diagnosed that there is a possibility of deterioration abnormality in the motor M.

[0158] Furthermore, for example, the diagnostic unit 1405 can diagnose the degree of deterioration of the motor M based on the magnitude of a predetermined frequency component. Specifically, the diagnostic unit 1405 can diagnose the degree of deterioration of the motor M in such a way that the greater the magnitude of the predetermined frequency component, the greater (higher) the degree of deterioration of the motor M. The criteria used to determine the degree of deterioration of the motor M can be fixed, or they can be changed, for example, according to the operating state of the motor M.

[0159] Thus, in this example, the control device 140 performs a diagnosis related to the deterioration anomaly of the motor M based on the frequency components of the instantaneous active power P and the instantaneous reactive power Q.

[0160] Therefore, the control device 140 can notify the user of the possibility of abnormal deterioration leading to mechanical failure of the motor M before the motor M malfunctions or the equipment including the motor M suddenly stops. Thus, the control device 140 reduces the frequency of maintenance of the equipment including the motor M, enables maintenance to be performed in accordance with the condition of the motor M, and reduces the risk of sudden stops of the equipment including the motor M, long-term shutdowns of equipment undergoing recovery operations, etc.

[0161] Furthermore, while focusing on the magnitudes of instantaneous active power P and instantaneous reactive power Q is possible, there is a possibility of misdiagnosing a deterioration anomaly in motor M by capturing instantaneous changes in these magnitudes. Additionally, in such cases, it may be impossible to perform diagnoses related to motor M's deterioration anomalies that are not reflected in the magnitudes of the instantaneous active power P and instantaneous reactive power Q.

[0162] In contrast, in this example, the control device 140 focuses on the frequency components of the instantaneous active power P and the instantaneous reactive power Q, thereby enabling more appropriate diagnosis related to the deterioration anomalies of the motor M.

[0163] In addition, for example, although it is possible to consider setting up a dedicated sensor for diagnosing the deterioration of the motor M, it is unavoidable to increase the cost of realizing the diagnostic function for the deterioration of the motor M.

[0164] In contrast, in this example, the control device 140 can perform diagnoses related to the deterioration and abnormalities of the motor M using only the outputs of the sensors 150 and 200 necessary for controlling the motor M. Therefore, the control device 140 can suppress the increase in cost and perform diagnoses related to the deterioration and abnormalities of the motor M.

[0165] It should be noted that the control device 140 can use only either the instantaneous active power P or the instantaneous reactive power Q to perform frequency component-based diagnosis related to the deterioration anomalies of the motor M.

[0166] [An example of diagnosis and handling of degradation anomalies]

[0167] Next, refer to Figure 9 An example of a diagnostic process for the deterioration of the motor M performed by the control device 140 will be described.

[0168] Figure 9 This is a flowchart that roughly illustrates an example of a diagnostic process for the deterioration of an electric motor M.

[0169] This flowchart is executed at a predetermined time. The predetermined time is, for example, the time when the power supply to the power conversion device 100 is turned on. Therefore, the control device 140 can perform diagnoses related to the deterioration abnormalities of the motor M in accordance with the power supply turn-on of the power conversion device 100. Alternatively, the predetermined time can be, for example, a time when a diagnostic request from a user is input via an input section provided in the power conversion device 100. Furthermore, the predetermined time can be, for example, a time when a diagnostic request from a user is input via the communication device 170, the management device 300, or the terminal device 400. Hereinafter, for the purposes of this discussion... Figure 14 The flowchart is the same. Furthermore, the specified timing could be, for example, the starting (running) of the motor M. Specifically, the specified timing could be a timing synchronized with the timing (control cycle) of the control of the motor M performed by the motor control unit 1401.

[0170] like Figure 9 As shown, in step S102, the power calculation unit 1402 obtains the latest data for calculating the latest instantaneous active power P and instantaneous reactive power Q. The latest data includes, for example, the latest d-axis current Id, q-axis current Iq, d-axis voltage command Vd*, and q-axis voltage command Vq*.

[0171] After the control device 140 completes the processing in step S102, it proceeds to step S104.

[0172] In step S104, the power calculation unit 1402 calculates the instantaneous active power P and instantaneous reactive power Q based on the data obtained in step S102.

[0173] After the control device 140 completes the processing in step S104, it proceeds to step S106.

[0174] In step S106, the analysis unit 1403 performs frequency analysis on the instantaneous active power P and instantaneous reactive power Q calculated in step S104.

[0175] After the control device 140 completes the processing in step S106, it proceeds to step S108.

[0176] In step S108, the feature quantity acquisition unit 1404 acquires the feature quantity (frequency feature quantity) related to the deterioration anomaly of the motor M based on the frequency analysis results of step S106.

[0177] After the control device 140 completes the processing in step S108, it proceeds to step S110.

[0178] In step S110, the diagnostic unit 1405 performs a diagnosis related to the deterioration abnormality of the motor M based on the characteristic quantity (frequency characteristic quantity) obtained in step S108.

[0179] After the diagnostic unit 1405 completes the processing in step S110, it proceeds to step S112.

[0180] In step S112, the diagnostic unit 1405 determines whether there is a possibility of deterioration or abnormality in the motor M. If there is a possibility of deterioration or abnormality in the motor M, the diagnostic unit 1405 proceeds to step S114; if there is no possibility of deterioration or abnormality in the motor M, it proceeds to step S116.

[0181] It should be noted that when the diagnostic unit 1405 diagnoses the degree of deterioration of the motor M, in step S112, it can be determined whether the degree of deterioration exceeds a predetermined benchmark. This benchmark is predetermined, for example, through experiments or computer simulations, as a lower limit for the degree of deterioration of the motor M at which maintenance of the motor M is deemed necessary. In this case, in step S114 (described later), it can be notified that the degree of deterioration of the motor M exceeds the predetermined benchmark. Furthermore, when the diagnostic unit 1405 diagnoses the degree of deterioration of the motor M, the process of notifying the user of the degree of deterioration of the motor M as a diagnostic result can be performed instead of steps S112 and S114 and S116 (described later). Additionally, when the deterioration diagnosis process is performed without relying on a diagnostic request from the user, for example, when it is performed when the power conversion device 100 is powered on, the process in step S116 (described later) can be omitted.

[0182] In step S114, the notification unit 1406 notifies the user of the diagnostic result that there is a possibility of deterioration or abnormality in the motor M through the display device 160 and the communication device 170.

[0183] It should be noted that Notification Department 1406 can also send a notification urging the user to perform maintenance on motor M.

[0184] After the control device 140 completes the processing in step S114, it ends the current flowchart processing.

[0185] On the other hand, through step S116, the notification unit 1406 notifies the user of the normal diagnostic result of the motor M via the display device 160 and the communication device 170.

[0186] After the control device 140 completes the processing in step S116, it ends the current flowchart processing.

[0187] [Another example of the functional composition of a power conversion device]

[0188] Next, refer to Figure 10 Another example of the functional configuration of the power conversion device 100 will be described below. Hereinafter, it will be compared with the example described above ( Figure 2 The explanation will focus on the different parts.

[0189] Figure 10 This is a functional block diagram illustrating another example of the functional configuration of the power conversion device 100 (control device 140) of this embodiment.

[0190] like Figure 10 As shown, similar to the example above, the control device 140 includes a motor control unit 1401, a power calculation unit 1402, an analysis unit 1403, a feature acquisition unit 1404, a diagnostic unit 1405, and a notification unit 1406. Part or all of the functions of each of the motor control unit 1401, power calculation unit 1402, analysis unit 1403, feature acquisition unit 1404, diagnostic unit 1405, and notification unit 1406 are implemented, for example, by loading a program installed in an auxiliary storage device into a memory device and being executed by the CPU.

[0191] Similar to the example above, the analysis unit 1403 performs an analysis relating to changes in instantaneous active power P and instantaneous reactive power Q, indicating the development of abnormal deterioration of the motor M. Specifically, unlike the example above, the analysis unit 1403 includes a frequency analysis unit 1403A and an amplitude analysis unit 1403B.

[0192] Similar to the analysis unit 1403 in the example above, the frequency analysis unit 1403A performs frequency analysis on the instantaneous active power P and the instantaneous reactive power Q.

[0193] It should be noted that the analysis unit 1403 in the above example is equivalent to the configuration that only includes the frequency analysis unit 1403A in the frequency analysis unit 1403A and the amplitude analysis unit 1403B.

[0194] As described later, the amplitude analysis unit 1403B performs an analysis (hereinafter referred to as "amplitude analysis") related to the amplitude of the vibration component (hereinafter simply referred to as "amplitude of the vibration component") generated in the instantaneous active power P and instantaneous reactive power Q, which has a wavelength shorter than the fundamental wave. Details will be described later (see [reference]). Figure 11 ).

[0195] Similar to the example above, the feature quantity acquisition unit 1404 acquires feature quantities related to the deterioration anomaly of the motor M based on the analysis results of the analysis unit 1403. Specifically, unlike the example above, the feature quantity acquisition unit 1404 includes feature quantity acquisition units 1404A and 1404B.

[0196] Similar to the feature acquisition unit 1404 in the example above, the feature acquisition unit 1404A acquires frequency feature quantities based on the results of frequency analysis performed by the analysis unit 1403 (frequency analysis unit 1403A).

[0197] It should be noted that the analysis unit 1403 in the above example is equivalent to only including the feature quantity acquisition unit 1404A in the feature quantity acquisition units 1404A and 1404B.

[0198] The characteristic quantity acquisition unit 1404B acquires characteristic quantities (hereinafter referred to as "amplitude characteristic quantities") of the amplitude of the vibration components focusing on the instantaneous active power P and instantaneous reactive power Q, based on the amplitude analysis performed by the amplitude analysis unit 1403B. Details will be described later (see [reference]). Figure 12 , Figure 13 ).

[0199] Similar to the case in the example above, the diagnostic unit 1405 performs a diagnosis related to the deterioration abnormality of the motor M based on the frequency characteristic quantity obtained by the characteristic quantity acquisition unit 1404 (characteristic quantity acquisition unit 1404A).

[0200] Furthermore, similar to the example above, the diagnostic unit 1405 performs a diagnosis related to the deterioration anomaly of the motor M based on the amplitude characteristic quantity obtained by the characteristic quantity acquisition unit 1404 (characteristic quantity acquisition unit 1404B). Details will be described later (see [reference]). Figure 12 , Figure 13 ).

[0201] [Another example of diagnostic methods related to abnormal deterioration of electric motors]

[0202] Next, in addition to the above Figure 4 , Figure 5 In addition, refer to Figures 11-13 Another example of a diagnostic method related to abnormal deterioration of motor M will be illustrated.

[0203] Figure 11 This is a graph representing an example of the amplitude analysis results of the instantaneous active power P and instantaneous reactive power Q of the motor M. Figure 12 This is a figure illustrating an example of a diagnostic method for degradation anomalies based on amplitude analysis results. Figure 13 This is another example of a diagnostic method for degradation anomalies based on amplitude analysis results.

[0204] like Figure 4 , Figure 5 As shown above, when the motor M deteriorates to a certain extent, vibration components sometimes appear in the amplitudes of its instantaneous active power P and instantaneous reactive power Q. Furthermore, as the motor M deteriorates further, these vibration components become more pronounced.

[0205] Therefore, in this example, the control device 140 focuses on the amplitude of the vibration components with wavelengths shorter than the fundamental wave generated in the instantaneous active power P and instantaneous reactive power Q of the motor M, and performs a diagnosis related to the deterioration anomaly of the motor M.

[0206] Specifically, as described above, the amplitude analysis unit 1403B performs vibration analysis on instantaneous active power P and instantaneous reactive power Q.

[0207] For example, such as Figure 11 As shown, the amplitude analysis unit 1403B obtains the peak values ​​of the amplitudes of instantaneous active power P and instantaneous reactive power Q using a waveform counting method. The peak value corresponds to the difference between the peak of the amplitude being measured and the peak of the previous amplitude. Furthermore, the amplitude analysis unit 1403B can allocate the obtained peak values ​​to each specified range, obtaining the number of measurements of the peak values ​​within each specified range. For example, known methods such as the minimax method, maximum-minimum method, amplitude method, level crossing method, range pair counting method, and rainflow method can be applied.

[0208] Additionally, for example, such as Figure 5As shown, the amplitude analysis unit 1403B can acquire time series waveform data equivalent to the vibration components generated in the amplitude of instantaneous active power P and instantaneous reactive power Q.

[0209] As described above, the characteristic quantity acquisition unit 1404B acquires a characteristic quantity (amplitude characteristic quantity) of the amplitude of the vibration components focusing on the instantaneous active power P and instantaneous reactive power Q based on the analysis results of the amplitude analysis unit 1403B.

[0210] For example, the characteristic quantity acquisition unit 1404B acquires the number of measurements of peak values ​​exceeding a predetermined reference (threshold Pk_th) among the peak values ​​acquired by the amplitude analysis unit 1403B, or the ratio (hereinafter referred to as "measurement rate") relative to the total number of measurements, as amplitude characteristic quantities. This is because the peak values ​​of the amplitudes of instantaneous active power P and instantaneous reactive power Q can be considered equivalent to the amplitudes of vibration components, and the larger the peak value, the more the abnormal deterioration of the motor M develops.

[0211] The specified benchmark (threshold Pk_th) can be a fixed value or a variable value that can be changed, for example, based on the operating state of the motor M. Furthermore, the specified benchmark (threshold Pk_th) can be the same or different in the case of instantaneous active power P and instantaneous reactive power Q.

[0212] Furthermore, for example, as an amplitude characteristic quantity, the characteristic quantity acquisition unit 1404B can obtain the amplitude value of the vibration component from the waveform data of the time series of the vibration components of the amplitude of the instantaneous active power P and instantaneous reactive power Q obtained by the amplitude analysis unit 1403B. This is because it can be considered that the larger the amplitude value of the vibration component, the more relatively developed the degradation anomaly.

[0213] As described above, the diagnostic unit 1405 performs a diagnosis related to the deterioration anomaly of the motor M based on the amplitude characteristic quantity.

[0214] For example, such as Figure 12 As shown, if the number of measurements or the measurement rate of the peak value (enclosed by the dashed line in the figure) exceeding the threshold Pk_th, which is an amplitude characteristic quantity, exceeds the specified reference (threshold N_th), the diagnostic unit 1405 diagnoses the possibility of deterioration abnormality of the motor M.

[0215] The specified reference (threshold N_th) can be a fixed value or a variable value that can change according to, for example, the operating state of the motor M. Furthermore, the specified reference (threshold N_th) can be the same or different in the case of instantaneous active power P and instantaneous reactive power Q.

[0216] Furthermore, for example, the diagnostic unit 1405 can diagnose the degree of deterioration of the motor M based on the number of measurements or measurement rate of peak values ​​exceeding a threshold Pk_th, which is an amplitude characteristic quantity. Specifically, the diagnostic unit 1405 diagnoses the degree of deterioration of the motor M in such a way that the greater the number of measurements or measurement rate of peak values ​​exceeding the threshold Pk_th, the greater (higher) the degree of deterioration of the motor M. The criteria used to determine the degree of deterioration of the motor M can be fixed or can be varied, for example, according to the operating state of the motor M.

[0217] Additionally, for example, such as Figure 13 As shown, if the amplitude value of the vibration component, which is an amplitude characteristic quantity, exceeds a specified reference (threshold A_th), the diagnostic unit 1405 diagnoses the possibility of a deterioration abnormality in the motor M.

[0218] The specified reference (threshold A_th) can be a fixed value or a variable value that can change according to, for example, the operating state of the motor M. Furthermore, the specified reference (threshold A_th) can be the same or different for the instantaneous active power P and the instantaneous reactive power Q.

[0219] Furthermore, for example, the diagnostic unit 1405 can diagnose the degree of deterioration of the motor M based on the amplitude value of the vibration component, which is an amplitude characteristic quantity. Specifically, the diagnostic unit 1405 diagnoses the degree of deterioration of the motor M in a manner that the larger the amplitude value of the vibration component of the amplitude of the instantaneous active power P and the instantaneous reactive power Q, the greater (higher) the degree of deterioration of the motor M. Similar to the above, the criteria used to determine the degree of deterioration of the motor M can be fixed or changed, for example, according to the operating state of the motor M.

[0220] Thus, in this example, the control device 140 performs a diagnosis related to the deterioration anomaly of the motor M based on the vibration components of the instantaneous active power P and instantaneous reactive power Q, specifically based on the amplitude of the vibration components with wavelengths shorter than the fundamental wave.

[0221] Thus, similar to the case in the example above, the control device 140 suppresses the frequency of maintenance of the equipment including the motor M, can perform maintenance in accordance with the state of the motor M, and can reduce the risk of sudden stoppage of the equipment including the motor M, long-term stoppage of the equipment for its recovery operation, etc.

[0222] In addition, similar to the case in the example above, the control device 140 can appropriately diagnose abnormalities related to the deterioration of the motor M by focusing on the amplitude of the vibration components with wavelengths shorter than the fundamental wave in the instantaneous active power P and instantaneous reactive power Q.

[0223] In addition, in this example, the control device 140 performs a diagnosis related to the deterioration anomaly of the motor M based not only on the frequency components of the instantaneous active power P and the instantaneous reactive power Q, but also on the amplitude of the vibration component with a wavelength shorter than the fundamental wave.

[0224] Therefore, the control device 140 can perform diagnoses related to the deterioration abnormality of the motor M from two perspectives. Thus, even if, for example, the control device 140 cannot obtain signs of a fault (possibility of deterioration abnormality) in the motor M from one perspective, it can sometimes obtain signs of a fault in the motor M from another perspective. Therefore, the control device 140 can diagnose the possibility of a deterioration abnormality in the motor M earlier.

[0225] It should be noted that the control device 140 can use only either the instantaneous active power P or the instantaneous reactive power Q to perform a diagnosis related to the deterioration anomaly of the motor M based on the amplitude of the vibration component with a wavelength shorter than the fundamental wave. Alternatively, the control device 140 can perform only the latter diagnosis: a diagnosis based on the frequency components of the instantaneous active power P and instantaneous reactive power Q related to the deterioration anomaly of the motor M, and a diagnosis based on the amplitude of the vibration components of the instantaneous active power P and instantaneous reactive power Q related to the deterioration anomaly of the motor M.

[0226] [Another example of diagnosis and handling of deterioration anomalies]

[0227] Next, refer to Figure 14 Another example of the deterioration abnormality diagnosis and treatment of the motor M performed by the control device 140 will be described.

[0228] Figure 14 This is a flowchart that roughly illustrates another example of the diagnostic and handling process for the deterioration of motor M.

[0229] like Figure 14 As shown, due to steps S202 and S204 and Figure 9 The processes in steps S102 and S104 are the same, so the explanation is omitted.

[0230] After the control device 140 completes the processing in step S204, it proceeds to step S206.

[0231] In step S206, the analysis unit 1403 (frequency analysis unit 1403A and amplitude analysis unit 1403B) performs frequency analysis and amplitude analysis on the instantaneous active power P and instantaneous reactive power Q calculated in step S204.

[0232] After the control device 140 completes the processing in step S206, it proceeds to step S208.

[0233] In step S208, the feature quantity acquisition unit 1404 (feature quantity acquisition unit 1404A and feature quantity acquisition unit 1404B) acquires the feature quantities (frequency feature quantity and amplitude feature quantity) related to the deterioration anomaly of the motor M based on the results of the frequency analysis and amplitude analysis in step S206.

[0234] After the control device 140 completes the processing in step S208, it proceeds to step S210.

[0235] In step S210, the diagnostic unit 1405 performs a diagnosis related to the deterioration anomaly of the motor M based on the characteristic quantities (frequency characteristic quantity and amplitude characteristic quantity) obtained in step S208.

[0236] Specifically, the diagnostic unit 1405 performs a diagnosis related to the deterioration anomaly of the motor M based on frequency characteristic quantities, and performs a diagnosis related to the deterioration anomaly of the motor M based on amplitude characteristic quantities.

[0237] In addition, the diagnostic unit 1405 can perform a comprehensive diagnosis based on individual diagnostic results based on frequency characteristic quantities and individual diagnostic results based on amplitude characteristic quantities.

[0238] After the control device 140 completes the processing in step S210, it proceeds to step S212.

[0239] In step S212, the diagnostic unit 1405 determines whether there is a possibility of deterioration or abnormality in the motor M. For example, if either the individual diagnostic results based on frequency characteristic quantities or the individual diagnostic results based on amplitude characteristic quantities indicate a possibility of deterioration or abnormality in the motor M, the diagnostic unit 1405 determines that there is a possibility of deterioration or abnormality in the motor M. Alternatively, the diagnostic unit 1405 can determine whether there is a possibility of deterioration or abnormality in the motor M based on a comprehensive diagnostic result. If there is a possibility of deterioration or abnormality in the motor M, the diagnostic unit 1405 proceeds to step S214; if there is no possibility of deterioration or abnormality in the motor M, it proceeds to step S216.

[0240] It should be noted that, if the diagnostic unit 1405 diagnoses the degree of deterioration of the motor M, it can determine in step S212 whether the degree of deterioration exceeds a predetermined benchmark. The predetermined benchmark can be the same as the example mentioned above ( Figure 9The same applies to the case where, for example, in either a separate diagnostic result based on frequency characteristics or a separate diagnostic result based on amplitude characteristics, the degree of deterioration of motor M exceeds a predetermined benchmark, it is determined that the degree of deterioration of motor M exceeds the predetermined benchmark. Furthermore, as a comprehensive diagnostic result, it can be determined whether the degree of deterioration of motor M exceeds the predetermined benchmark. In this case, in step S214, the same applies to the case where, the motor M deteriorates beyond the predetermined benchmark. Figure 9 Similar to step S114, notification can be sent if the degree of deterioration of the motor M exceeds a predetermined standard. Furthermore, if the degree of deterioration of the motor M is diagnosed by the diagnostic unit 1405, in addition to steps S212 to S216, the user can be notified of the degree of deterioration of the motor M as a diagnostic result. Additionally, if the deterioration diagnosis process is performed without relying on a diagnostic request from the user, for example, when the power conversion device 100 is powered on, the process in step S216 can be omitted.

[0241] Because steps S214, S216 and Figure 9 The processes in steps S114 and S116 are the same, so the explanation is omitted.

[0242] After the control device 140 completes the processing in steps S214 and S216, it ends the current flowchart processing.

[0243] It should be noted that the deterioration anomaly diagnosis and processing of motor M based on the frequency components of instantaneous active power P and instantaneous reactive power Q, and the deterioration anomaly diagnosis and processing of motor M based on the amplitude of the vibration components of instantaneous active power P and instantaneous reactive power Q, can be implemented as separate and independent processes.

[0244] [effect]

[0245] Next, the function of the degradation anomaly diagnosis system 1 in this embodiment will be explained.

[0246] In this embodiment, the power conversion device 100 includes an inverter circuit 130, a sensor 150, a power calculation unit 1402, and a diagnostic unit 1405. Specifically, the motor M is driven by power input from an external source via the inverter circuit 130. The sensor 150 is used to detect the phase current of the motor M. The power calculation unit 1402 calculates at least one of the active power and reactive power of the motor M based on the output of the sensor 150. The diagnostic unit 1405 performs diagnostics related to deterioration anomalies of the motor M based on the frequency components of at least one of the active power and reactive power of the motor M.

[0247] Therefore, compared to cases where the diagnosis of motor M's deterioration abnormalities is based on, for example, the magnitude of the active and reactive power of the motor M, the power conversion device 100 is able to more appropriately diagnose the deterioration abnormalities of the motor M.

[0248] In addition, in this embodiment, the diagnostic unit 1405 can perform a diagnosis related to the deterioration abnormality of the motor M based on the change of a predetermined frequency component of at least one of the active power and reactive power of the motor M.

[0249] Therefore, the power conversion device 100 can capture, for example, the relative increase of a certain frequency component of the active power and reactive power of the motor M, and diagnose the abnormal development state of the deterioration of the motor M.

[0250] Furthermore, in this embodiment, the power conversion device 100 may include a tracking filter TF. Specifically, the tracking filter TF may output a predetermined frequency component of at least one of the active power and reactive power of the motor M, which varies in accordance with the rotational speed of the motor M. Moreover, the diagnostic unit 1405 may perform diagnoses related to deterioration anomalies of the motor M based on the output of the tracking filter TF.

[0251] Therefore, even when the specified frequency components of the active and reactive power of the motor M, which represent the abnormal development state of the motor M's deterioration, change according to the rotational speed of the motor M, the power conversion device 100 can appropriately perform diagnoses related to the abnormal deterioration of the motor M.

[0252] Furthermore, in this embodiment, the power conversion device 100 may include a characteristic quantity acquisition unit 1404. Specifically, the characteristic quantity acquisition unit 1404 can acquire a characteristic quantity (frequency characteristic quantity) related to a predetermined frequency component of at least one of the active power and reactive power of the motor M. Moreover, the diagnostic unit 1405 can diagnose the possibility of a deterioration abnormality in the motor M if the frequency characteristic quantity exceeds a first predetermined reference (e.g., a threshold Sp_th).

[0253] Therefore, by appropriately setting a first predetermined reference, the power conversion device 100 can specifically diagnose whether there is a possibility of abnormal deterioration of the motor M.

[0254] Furthermore, in this embodiment, the first specified reference can be changed according to the state of the motor M.

[0255] Therefore, the power conversion device 100 can appropriately diagnose abnormalities related to the deterioration of the motor M based on the condition of the motor M.

[0256] In addition, in this embodiment, the frequency characteristic quantity can be the magnitude of a predetermined frequency component of at least one of the active power and reactive power of the motor M, or the sum of the magnitudes of multiple predetermined frequency components of at least one of the active power and reactive power of the motor M.

[0257] Therefore, the power conversion device 100 can specifically capture the relative increase of the frequency components of the active power and reactive power of the motor M, thereby diagnosing the possibility of abnormal deterioration of the motor M.

[0258] In addition, in this embodiment, the diagnostic unit 1405 can perform a diagnosis related to the deterioration abnormality of the motor M based on the frequency component of at least one of the active power and reactive power of the motor M, and the amplitude of the vibration component.

[0259] Therefore, the power conversion device 100 can perform diagnoses related to the deterioration anomalies of the motor M from multiple perspectives. Thus, the power conversion device 100 can diagnose signs of failure (the possibility of deterioration anomalies) in the motor M at an earlier stage.

[0260] In addition, in this embodiment, the diagnostic unit 1405 can diagnose the possibility of abnormal deterioration of the motor M if the amplitude of the vibration component of at least one of the active power and reactive power of the motor M exceeds a second predetermined reference (e.g., threshold A_th).

[0261] Therefore, the power conversion device 100 can specifically capture the relative increase in the amplitude of the vibration components of the active power and reactive power of the motor M by appropriately setting the second specified reference, thereby diagnosing whether there is a possibility of abnormal deterioration of the motor M.

[0262] In addition, in this embodiment, the power conversion device 100 may include a notification unit 1406. Specifically, the notification unit 1406 may notify the user of the diagnostic results of the diagnostic unit 1405.

[0263] Thus, the power conversion device 100 enables the user to recognize the conditions related to the deterioration and abnormality of the motor M.

[0264] Furthermore, in this embodiment, the diagnostic function related to the deterioration abnormality of the motor M in the control device 140 can be transferred to the management device 300 and the terminal device 400. Specifically, the management device 300 and the terminal device 400 are configured to obtain the output of the sensor 150 of the power conversion device 100 and other similar sensors, and may include the same configuration as the power calculation unit 1402 and the diagnostic unit 1405.

[0265] Therefore, the management device 300 and the terminal device 400 are the same as the power conversion device 100 mentioned above, and can more appropriately diagnose abnormalities related to the deterioration of the motor M.

[0266] Although the embodiments have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and alterations can be made within the scope of the spirit described in the claims.

Claims

1. A power conversion device, comprising: The drive unit uses externally input electricity to drive the AC motor; The current detection unit detects the phase current of the aforementioned AC motor; The calculation unit, based on the output of the current detection unit, calculates at least one of the active power and reactive power of the AC motor; and The diagnostic department performs diagnoses related to the deterioration anomalies of the AC motor based on frequency characteristic quantities related to frequency components obtained through frequency analysis of at least one of the aforementioned active power and reactive power, and amplitude characteristic quantities related to vibration amplitude obtained through waveform counting. The waveform counting method mentioned above refers to a method of obtaining the amplitude characteristic quantity by allocating the peak value of the amplitude of at least one of the active power and the reactive power to each specified range and obtaining the number of measurements of the peak value in each specified range.

2. The power conversion device according to claim 1, wherein, The above waveform counting method is based on at least one of the following: maximum-minimum method, maximum-minimum method, amplitude method, horizontal cross method, process pair counting method, and rainflow method.

3. The power conversion device according to claim 2, wherein, This includes a tracking filter that outputs a predetermined frequency component based on at least one of the aforementioned active power and reactive power, which varies according to the rotational speed of the aforementioned AC motor. The diagnostic unit performs the aforementioned diagnosis based on the output of the aforementioned tracking filter.

4. The power conversion device according to claim 2, wherein, The system includes an acquisition unit that acquires the aforementioned frequency characteristic and amplitude characteristic. When the frequency characteristic value exceeds the first specified reference, the diagnostic unit performs the diagnosis that there is a possibility of the AC motor deteriorating abnormally.

5. The power conversion device according to claim 4, wherein, The aforementioned first specified standard changes according to the state of the aforementioned AC motor.

6. The power conversion device according to claim 4 or 5, wherein, The aforementioned frequency characteristic quantity is the magnitude of the specified frequency component of at least one of the aforementioned active power and the aforementioned reactive power, or the sum of the magnitudes of multiple specified frequency components of the aforementioned active power and the aforementioned reactive power.

7. The power conversion device according to any one of claims 1 to 3, wherein, The diagnostic unit performs the diagnosis of the possibility of the aforementioned AC motor deterioration when the amplitude characteristic exceeds the second specified reference.

8. The power conversion device according to any one of claims 1 to 3, wherein, This includes the notification department, which notifies the user of the diagnostic results from the aforementioned diagnostic department.

9. A diagnostic device, comprising: The arithmetic unit acquires the output of the current detection unit that detects the phase current of the AC motor, and calculates at least one of the active power and reactive power of the AC motor; and The diagnostic department performs diagnoses related to the deterioration anomalies of the AC motor based on frequency characteristic quantities related to frequency components obtained through frequency analysis of at least one of the aforementioned active power and reactive power, and amplitude characteristic quantities related to vibration amplitude obtained through waveform counting. The waveform counting method mentioned above refers to a method of obtaining the amplitude characteristic quantity by allocating the peak value of the amplitude of at least one of the active power and the reactive power to each specified range and obtaining the number of measurements of the peak value in each specified range.

10. A diagnostic method, comprising: The calculation step involves the diagnostic device acquiring the output of a current detection unit that detects the phase current of an AC motor, and calculating at least one of the active power and reactive power of the AC motor based on the output of the current detection unit. as well as The diagnostic step involves the diagnostic device performing a diagnosis related to the deterioration anomaly of the AC motor based on frequency characteristic quantities related to frequency components obtained through frequency analysis of at least one of the active power and reactive power, and amplitude characteristic quantities related to vibration amplitude obtained through waveform counting. The waveform counting method mentioned above refers to a method of obtaining the amplitude characteristic quantity by allocating the peak value of the amplitude of at least one of the active power and the reactive power to each specified range and obtaining the number of measurements of the peak value in each specified range.

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