JP2019088134A - Motor control device - Google Patents

Abstract

To enable an accurate abnormality diagnosis of an input voltage detection, even when a power supply of a motor is separated from a motor control device.SOLUTION: A control section 3 superimposes harmonic current to a motor 5, controls a switching section 2 without rotating the motor 5, determines a rotation stop of the motor 5 from a rotational angle of the motor 5 estimated by a rotational angle estimation section 6 on the basis of each phase current generating in each phase of the motor 5, and determines whether or not a detection result of an input voltage detection section 7 is abnormal, by estimating input voltage after performing a harmonic current control from an initial input voltage value of power storage elements 9 detected by the input voltage detection section 7 before performing the harmonic current control, and by comparing an estimation result with the input voltage detected by the input voltage detection section 7.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor control device, and more particularly to a motor control device that performs a detection abnormality diagnosis of a detected input voltage in motor control of an inverter for an electric vehicle or a hybrid vehicle.

  The motor control device controls the torque of the motor by controlling the amount of current supplied from the power supply. Specifically, the motor control device controls the ON / OFF time of the switch element based on the input voltage applied to the switch element constituting the inverter and the amount of current supplied to the motor, and the amount of current supplied to the motor Control the torque control.

  However, when torque control is performed in an abnormal state in which the input voltage applied to the switch element is abnormal, the motor can not be rotated with a normal torque. As a result, the motor may perform unintended acceleration or unintended deceleration. Therefore, it is necessary to detect whether the input voltage is abnormal.

  On the other hand, in the case of in-vehicle devices in electric vehicles or hybrid vehicles, application of functional safety standards, specifically, for example, ISO26262 is strongly desired. Therefore, a detection abnormality diagnosis function of the input voltage for diagnosing that there is no detection abnormality in the detection result of the input voltage detected by the input voltage detection unit is required.

  If this detection abnormality diagnosis function is not available, the abnormality detection result may be judged as normal if the input voltage detection unit itself can not correctly diagnose the detection abnormality even though the input voltage is in an abnormal state. There is sex. In that case, it will not be detected that the input voltage is in an abnormal state.

  Further, there is a case where the abnormality diagnosis of the input voltage is performed in a state where the power supply of the motor and the motor control device are separated. At this time, if the abnormality diagnosis is performed while the motor is rotating, the induced voltage is added to the input voltage due to the generation of the induced voltage. Therefore, the abnormality diagnosis of the input voltage can not be accurately performed. Therefore, in order to perform abnormality diagnosis correctly, it is necessary to determine that the rotation of the motor is stopped or that the rotation of the motor is low enough not to affect the input voltage abnormality diagnosis. It becomes.

  Therefore, a voltage sensor abnormality diagnosis apparatus has been proposed which has a function of determining whether or not the number of revolutions of the motor is in the low revolution region (for example, see Patent Document 1). Patent Document 1 first obtains an estimated value of input voltage in a low rotation region. Next, Patent Document 1 compares the estimated value of the input voltage with the input voltage sensor value detected by the input voltage sensor, and when the absolute value of the difference is larger than the threshold value, the input voltage sensor Judge as abnormal.

JP 2017-93151 A

  However, the conventional apparatus described in Patent Document 1 has the following problems.

  The conventional device described in Patent Document 1 diagnoses an abnormality of the input voltage detection unit by comparing the estimated value of the input voltage with the input voltage sensor value. Therefore, in the conventional device, it is necessary to make a diagnosis by fluctuating the input voltage input to the motor control device.

  In addition, the conventional device executes the “discharge process” in which the remaining charge of the capacitor is discharged as heat after the power path is cut off by the power supply relay when the vehicle is stopped. In addition, the conventional device recognizes that the "discharge process" is being performed as a low rotation area, and performs abnormality diagnosis. Therefore, the conventional apparatus has a problem that it is necessary to separately add an input voltage control function such as a discharge processing function for input voltage abnormality diagnosis.

  In addition, there are also cases where abnormality determination is performed when the vehicle is activated or terminated. However, when the vehicle is started, the user operates the vehicle quickly, and when the vehicle is ended, the user quickly terminates the operation of the vehicle. It is desirable not to consume the

  However, as described above, the conventional device described in Patent Document 1 executes the "discharge process" when the vehicle is stopped, and performs the abnormality diagnosis during the execution of the "discharge process". Therefore, the conventional apparatus has a problem that the amount of processing of the program is increased to execute the “discharge process”, and a large amount of power is consumed.

  The present invention has been made to solve such a problem, and it is possible to suppress the consumption of power even when the motor power supply and the motor control device are disconnected without adding an input voltage control function separately. An object of the present invention is to provide a motor control device capable of accurately diagnosing an abnormality in input voltage detection.

  The present invention comprises a phase current detection unit for detecting a phase current of each phase of a motor, and a rotation angle estimation unit for calculating an estimated value of the rotation angle of the motor based on the phase current detected by the phase current detection unit. A switching unit that switches a current conduction path to each phase of the motor, a storage element connected to both ends of the switching unit, and an input voltage detection unit that detects an input voltage applied to the storage element; In the normal control mode, switching control of the current application path is performed by switching ON / OFF of the switch element of the switching unit, and in the abnormality diagnosis mode, abnormality diagnosis on the detection result of the input voltage of the input voltage detection unit is performed. A control unit, a power supply connected to both ends of the switching unit and both ends of the storage element, and a connection between the power supply and the storage element, and in an OFF state And the power shutoff unit for shutting off the power supply to the storage element. The control unit switches the power shutoff unit to the OFF state in the abnormality diagnosis mode, and In a state in which the current supply to the storage element is stopped, harmonic superposition control is performed to superimpose a harmonic current of the range in which the motor does not rotate on the motor to generate a harmonic current in each phase of the motor The motor based on the estimated value of the rotation angle determined by the rotation angle estimation unit using the phase current on which the harmonics are detected by the phase current detection unit during execution of the harmonic superposition control; If it is determined that the motor is in the rotation stop state, the input voltage detected by the input voltage detection unit; Note that the input voltage detection unit detects the input voltage based on the normal value of the input voltage detected by the input voltage detection unit when the input voltage detection unit executes the harmonic superposition control during normal operation. It is a motor control apparatus which performs the said abnormality diagnosis regarding a result.

  According to the motor control device according to the present invention, the harmonic superposition control is performed in a state where the current supply from the power source to the storage element is stopped, and the voltage of the storage element is reduced, thereby the input voltage for abnormality diagnosis. Since the detection result of the input voltage of the detection unit is obtained, there is no need to separately provide an input voltage control function, and power consumption is suppressed even when the motor power supply and the motor control device are disconnected. Anomaly diagnosis of input voltage detection is possible accurately.

FIG. 1 is a block diagram showing a configuration of a motor control device according to Embodiment 1 of the present invention. FIG. 7 is a diagram showing an example of a voltage detection result of the storage element detected by the input voltage detection unit when the input voltage detection unit is in the normal state and the abnormal state during harmonic wave superposition control according to the first embodiment of the present invention. The figure which showed another example of the voltage detection result of the electrical storage element which the input voltage detection part detected when the input voltage detection part is a normal state and an abnormal state at the time of harmonic superimposition control which concerns on Embodiment 1 of this invention. is there. It is the flowchart which showed the flow of the process of the abnormality diagnosis in the motor control apparatus which concerns on Embodiment 1 of this invention.

  Hereinafter, a preferred embodiment of a motor control device according to the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

Embodiment 1
FIG. 1 is a block diagram showing a configuration of a motor control device according to Embodiment 1 of the present invention. The motor control device controls the motor 5. As shown in FIG. 1, the motor control device includes a switching unit 2, a control unit 3, a phase current detection unit 4, a rotation angle estimation unit 6, an input voltage detection unit 7, a power shutoff unit 8, and a storage element 9. Is configured. The motor control device is connected to the power supply 1 via the power shutoff unit 8.

  Each of these configurations will be described below.

  The switching unit 2 is configured by connecting in series three switch element series bodies provided for each of the U-phase, V-phase, and W-phase of the motor 5. In each switch element series body, the first switch elements UH, VH and WH are respectively one for the second switch elements UL, VL and WL for each of the U phase, V phase and W phase. Connected in series in pairs. Further, connection points between the first switch element and the second switch element are respectively connected to U-phase, V-phase, and W-phase of the motor 5.

  Specifically, the connection point between the first switch element UH and the second switch element UL is connected to the U phase of the motor 5. Similarly, the connection point between the first switch element VH and the second switch element VL is connected to the V phase of the motor 5. Similarly, the connection point between the first switch element WH and the second switch element WL is connected to the W phase of the motor 5.

  The first switch elements UH, VH, WH and the second switch elements UL, VL, WL switch ON / OFF in accordance with a control signal from the control unit 3. Thereby, the current conduction path to each of the U-phase, V-phase, and W-phase of the motor 5 is switched.

  The phase current detection unit 4 is configured to include phase current detectors CTu, CTv, and CTw attached to the U phase, the V phase, and the W phase of the motor 5, respectively. The phase current detection unit 4 detects the phase current of each of the U phase, the V phase, and the W phase using the phase current detectors CTu, CTv, and CTw. The rotation angle estimation unit 6 and the control unit 3 read the phase current detected by the phase current detection unit 4.

  The motor 5 is composed of a three-phase motor consisting of U, V and W phases.

  The rotation angle estimation unit 6 calculates the phase voltage based on the phase current input from the phase current detection unit 4. Furthermore, the rotation angle estimation unit 6 performs calculation processing of rotation angle estimation using the phase voltage, and outputs an estimated value of the rotation angle to the control unit 3. The specific method of rotation angle estimation will be described later.

  The motor control device has two control modes, that is, a normal control mode and an abnormality diagnosis mode. The motor control device controls the rotation of the motor 5 based on the rotation angle of the motor 5 in the normal control mode. Therefore, in order to perform the said control, the rotation angle estimation part 6 may be previously mounted in the vehicle as normal equipment. In that case, it is not necessary to newly add the rotation angle estimation unit 6 for the present embodiment, and it is possible to use the rotation angle estimation unit 6 mounted in advance as it is.

  In the normal control mode, control unit 3 estimates the rotational angle input from rotational angle estimation unit 6, the phase current input from phase current detection unit 4, and the input voltage input from input voltage detection unit 7. And control ON / OFF of the switch element of the switching unit 2. As a result, the current conduction path of the switching unit 2 is switched. In the normal control mode, the motor control of the motor 5 is performed in this manner.

  On the other hand, in the abnormality diagnosis mode, the control unit 3 determines whether the detection result of the input voltage detected by the input voltage detection unit 7 is an abnormal state. When performing an abnormality diagnosis, the control unit 3 switches the control mode from the normal control mode to the abnormality diagnosis mode. Furthermore, when switching from the normal control mode to the abnormality diagnosis mode, the control unit 3 switches the power shutoff unit 8 from ON to OFF.

  If there is no problem as a result of the abnormality diagnosis in the abnormality diagnosis mode, the control unit 3 returns the control mode from the abnormality diagnosis mode to the normal control mode. The operation of the abnormality diagnosis mode will be described later.

  Here, the hardware configuration of the control unit 3 will be described. The control unit 3 includes, for example, a processor and a memory. The processor realizes each function of the normal control mode and each function of the abnormality diagnosis mode by reading and executing the program stored in the memory.

  The input voltage detection unit 7 detects an input voltage applied to both ends of the storage element 9.

  The power supply 1 has a positive terminal and a negative terminal. The positive terminal is connected to the storage element 9 through the power shutoff unit 8. The negative terminal is directly connected to storage element 9.

  One terminal of the power shutoff unit 8 is connected to the positive terminal of the power supply 1. The other terminal is connected to the storage element 9 and the first switch elements UH, VH, WH. When the power shutoff unit 8 is ON, the power supply 1 and the storage element 9 are connected, and a current is supplied from the power supply 1 to the storage element 9. When the power cut-off unit 8 is OFF, the connection between the power supply 1 and the storage element 9 is cut off, and the current supply from the power supply 1 to the storage element 9 is stopped.

  One terminal of the storage element 9 is connected to the first switch elements UH, VH, and WH. The other terminal of the storage element 9 is connected to the second switches UL, VL, and WL. When at least one of the first switch elements UH, VH, WH is ON and at least one of the second switches UL, VL, WL is ON, the electric storage element 9 to the motor 5 are formed according to the formed current conduction path. Current is supplied to the

  The motor control device according to the first embodiment is configured as described above, and diagnoses whether or not the detection result of the input voltage detection unit 7 is in the abnormal state in the abnormality diagnosis mode. When carrying out abnormality diagnosis, first, the control unit 3 superimposes a high frequency current having a frequency twice as high as that of the fundamental wave on the motor 5 to control the switching unit 2 without rotating the motor 5 Do.

  The control to superimpose the high frequency generates a high frequency current in each phase of the motor 5. The rotation angle estimation unit 6 calculates an estimated value of the rotation angle of the motor 5 based on the generated phase current. The control unit 3 determines whether the motor 5 is in the rotation stop state based on the estimated value of the rotation angle.

  At this time, the input voltage detection unit 7 detects the voltage of the storage element 9 which is decreasing due to the control of superimposing the high frequency. The control unit 3 compares the voltage detection result in the normal state stored in advance as a waveform pattern for comparison with the voltage value detected by the input voltage detection unit 7 so that the detection result of the input voltage detection unit 7 is It is determined whether or not it is an abnormal state.

  Hereinafter, a method of estimating the rotation angle of the rotor of the motor 5 in a state where the high frequency current is superimposed on the motor 5 will be described.

  First, motor control of the motor 5 will be described. Motor control is performed by vector control in two orthogonal axes. Two orthogonal axes are, for example, a d-axis (direct-axis) and a q-axis (quadrature-axis). The control unit 3 usually performs motor control such that a sinusoidal current synchronized with the electrical rotation frequency of the rotor of the motor 5 flows.

  Furthermore, the control unit 3 controls ON / OFF of the switch element of the switching unit 2 so that a high frequency current having a frequency higher than the electrical rotation frequency of the rotor of the motor 5 is superimposed on the sinusoidal current. Do. The superimposed high frequency current is controlled to have a current value that does not affect the generated torque of the motor 5, that is, does not affect the acceleration or deceleration of the rotation of the motor 5.

  Here, the high frequency refers to a frequency approximately twice or more of the electrical rotational frequency at the maximum rotational speed of the motor 5, for example, the highest electrical of the motor often used as a drive motor for electric vehicles or hybrid vehicles. When the rotation frequency is 1.2 kHz, the high frequency current has a frequency of about 2.4 kHz or more.

  Here, a voltage command value of d axis to be applied to flow a high frequency target current is Vdhf_ref, and a voltage command value of q axis is Vqhf_ref. These voltage command values Vdhf_ref and Vqhf_ref are represented on the dq axes. Therefore, in order to obtain the three-phase applied voltage to the motor 5, it is necessary to perform two-phase / three-phase conversion from the two-phase dq axis to the three-phase U-V-W axis.

  The voltage command values obtained by the two-phase / three-phase conversion are hereinafter referred to as voltage command values Vu_ref, Vv_ref, and Vw_ref. The control unit 3 turns on / off the U-phase, V-phase, and W-phase switch elements of the switching unit 2 from the relationship between the input voltage Vin detected by the input voltage detection unit 7 and the voltage command values Vu_ref, Vv_ref, and Vw_ref. Set the pulse width of. Thus, the high frequency current is superimposed on the motor 5 by switching ON / OFF of the switch element with the set pulse width.

  Next, the principle of the method of estimating the rotation angle of the rotor of the motor 5 in the state in which the high frequency current is superimposed will be described. The estimation of the rotation angle of the rotor is specifically performed based on the following principle. First, in the relationship between the current and voltage of the motor 5 represented on the dq axes, the coil resistance component becomes relatively extremely small compared to the inductance component since the current to be superimposed is a high frequency. Therefore, it is represented by the following equation 1.

Here, ω _hf is the electrical angular frequency of the high frequency superimposed current to be applied, L _dhf is the high frequency inductance of the d axis, L _qhf is the high frequency inductance of the q axis, and L _dqhf is the d axis resulting from the q high frequency current The interference component to the high frequency inductance _Lqdhf is an interference component to the high frequency inductance of the q axis caused by the high frequency current of the d axis.

In the estimation of the rotation angle, the coordinate axis equivalent to the d axis in the estimation operation with respect to the true d axis is represented as the γ axis. A high frequency current of only the d axis is intended to flow, and a sinusoidal high frequency voltage represented by the following equation 2 is applied to the γ axis corresponding to the d axis in the estimation operation. At this time, the high frequency current i _dhf flowing in the d axis is expressed by the following equation 3. The high frequency current _iqhf flowing in the q axis is expressed by the following equation 4. Here, Δθ in Equation 3 and Equation 4 is a deviation angle between the d axis and the γ axis.

  Now, it is assumed that a high frequency voltage represented by the above equation 2 is applied to the γ axis, and a current delayed in phase by a power factor angle φ with respect to the γ axis is supplied. When the γ-axis and the d-axis exactly coincide, no current flows in the d-axis, that is, the q-axis orthogonal to the γ-axis. Therefore, if the phase angle to be estimated is adjusted so that the equation 4 becomes zero, the d-axis coincides with the γ-axis. Further, the estimated calculation value of the phase angle at that time is a true value. Based on this principle, the rotation angle estimation unit 6 performs estimation calculation of the rotation angle. The relationship between Δθ and the power factor angle φ in high frequency component superposition is expressed by the following equation 5.

  In the above description, the high frequency current is superimposed on the motor 5. However, using a harmonic current synchronized with the power supply frequency as the high frequency current makes processing easier. Therefore, in the following, a harmonic current will be described as an example of the high frequency current. Further, controlling the switching unit 2 in a state where the motor 5 is made to superimpose a harmonic current and the motor 5 is not rotated is hereinafter referred to as “harmonic superposition control”.

  Next, a method of diagnosing abnormality of the input voltage in the abnormality diagnosis mode will be described. In the abnormality diagnosis mode, the control unit 3 switches the power shutoff unit 8 from ON to OFF. As a result, the power supply 1 and the storage element 9 are disconnected. In this state, when the harmonic superposition control is performed, the energy charged in the storage element 9 is consumed by the switching unit 2 or the motor 5 and decreases.

  The energy consumed changes depending on the voltage of the storage element 9 and the ratio of the ON time to the OFF time of the switching unit 2 controlled by the control unit 3 (hereinafter referred to as the DUTY ratio). The duty ratio is in the range of 0 to 1. Specifically, as the voltage of the storage element 9 is higher and the duty ratio is closer to 1, the energy consumed is larger.

  Further, when executing the harmonic superposition control according to the first embodiment, control unit 3 performs control such that the duty ratio decreases if the voltage of storage element 9 is high, and if the voltage of storage element 9 is low. Control is made to increase the duty ratio.

  Here, FIG. 2 and FIG. 3 explain the input voltage detection result of the storage element 9 detected by the input voltage detection unit 7 when the input voltage detection unit 7 is in the normal state and the abnormal state at the time of harmonic superposition control. Do. In FIGS. 2 and 3, the horizontal axis represents time, and the vertical axis represents the detection result of the input voltage of the storage element 9 by the input voltage detection unit 7. (A), (b), (c), (d), (e), (f), (g) and (h) shown in FIGS. 2 and 3 respectively show the following contents. .

  First, FIGS. 2A to 2D when the detection sensitivity is considered will be described. FIG. 2A shows the input voltage detection result of the input voltage detection unit 7 when the harmonic superposition control is performed when the detection sensitivity of the input voltage detection unit 7 is normal. The normal waveform of (a) is used as a comparison waveform pattern at the time of abnormality diagnosis. Therefore, the waveform of (a) is measured in advance and stored in a memory as a storage unit provided in the control unit 3.

  (B) shows the input voltage detection result of the input voltage detection unit 7 when the harmonic superimposition control is performed at the time of “detection sensitivity high abnormality” which is higher than the case where the detection sensitivity of the input voltage detection unit 7 is normal. It shows.

  As understood from comparison between (a) and (b), when the detection sensitivity of the input voltage detection unit 7 is higher than normal, that is, in the case of (b), the input detected by the input voltage detection unit 7 The voltage is higher than the normal detection result of (a). Therefore, the control unit 3 controls the duty ratio to be smaller than that in the normal state. As a result, the reduction amount of the voltage of the storage element 9 becomes smaller than that in the normal state.

  (C) shows the input voltage detection result of the input voltage detection unit 7 when the harmonic superimposition control is performed at the “detection sensitivity low abnormality time” lower than the case where the detection sensitivity of the input voltage detection unit 7 is normal. It shows.

  As understood from comparison between (a) and (c), when the detection sensitivity of the input voltage detection unit 7 is lower than normal, that is, in the case of (c), the input detected by the input voltage detection unit 7 The voltage is lower than the normal detection voltage of (a). Therefore, the control unit 3 controls the duty ratio to be larger than that in the normal state. As a result, the reduction amount of the voltage of the storage element 9 becomes larger than that in the normal state.

  (D) shows the input voltage detection result of the input voltage detection unit 7 when the harmonic superposition control is performed in the "intermediate sticking abnormality" in which the detection result of the input voltage detection unit 7 is fixed. . In this case, the detection result of the input voltage detection unit 7 is a fixed value. Therefore, the value of the initial input voltage when the time is 0 is maintained as it is as the input voltage detection result.

  Next, FIGS. 3 (a) and 3 (e) to (h) will be described in which the detected offset amount is taken into consideration, unlike FIG. FIG. 3A shows the input voltage detection result of the input voltage detection unit 7 when the harmonic superposition control is performed when the detection offset amount of the input voltage detection unit 7 is normal.

  (E) is a case where harmonic superposition control is performed in a state in which a voltage corresponding to “offset high abnormality time” higher than that in the normal case is actually applied to the detection offset amount of the input voltage detection unit 7 7 shows the result of detection of the input voltage of the input voltage detection unit 7 in the normal state. Therefore, in the waveform of (e), the input voltage is generally offset higher than the waveform in the normal state of (a).

  (F) shows the input voltage detection result of the input voltage detection unit 7 when the harmonic superposition control is performed at the “offset high abnormality time” which is higher than the case where the detection offset amount of the input voltage detection unit 7 is normal. Is shown.

  Here, the difference between (e) and (f) is as follows. (E) shows the case where the detection result of the input voltage detection unit 7 is normal when the harmonic superposition control is performed by the voltage offset to the positive side. On the other hand, (f) shows the case where the detection result of the input voltage detection unit 7 is abnormal when the harmonic superposition control is performed by the voltage offset to the positive side.

  As can be seen by comparing the detection result of the input voltage detection unit 7 in the normal state (e) with the abnormal state (f), the value of the input voltage detected as the abnormal state (f) is the normal state It is higher than the value of the input voltage detected as (e). Therefore, the control unit 3 controls the duty ratio at the time of abnormality of the input voltage detection unit 7 to be smaller than that at the normal time. As a result, the reduction amount of the voltage of the storage element 9 becomes smaller than that in the normal state.

  (G) is a case where the harmonic superposition control is performed in a state where a voltage corresponding to "offset low abnormality" which is lower than the case where the detection offset amount of the input voltage detection unit 7 is normal is actually applied. 7 shows the result of detection of the input voltage of the input voltage detection unit 7 in the normal state. Therefore, in the waveform of (g), the input voltage is generally offset lower than the waveform in the normal state of (a).

  However, the input voltage detection unit 7 outputs all 0 as normal when the detection voltage is 0 or less. Therefore, in FIG. 3 (g), the detected voltage is maintained at 0 after the detected voltage decreases and reaches 0.

  (H) is the input voltage detection result of the input voltage detection unit 7 when the harmonic superposition control is performed at the “offset low abnormality time” where the detection offset amount of the input voltage detection unit 7 is lower than that in the normal case. Is shown.

  Here, the difference between (g) and (h) is as follows. (G) has shown the case where the detection result of the input voltage detection part 7 is normal, when harmonic superimposition control is performed by the voltage offset by the negative | minus side. On the other hand, (h) shows the case where the detection result of the input voltage detection unit 7 is abnormal when the harmonic superposition control is performed by the voltage offset to the negative side.

  As can be seen by comparing the detection result of the input voltage detection unit 7 in the normal state (g) with the abnormal state (h), the value of the input voltage detected as the abnormal state (h) is the normal state Lower than the value of the input voltage detected as (g). Therefore, the control unit 3 controls the duty ratio at the time of abnormality of the input voltage detection unit 7 to be larger than that at the normal time. As a result, the reduction amount of the voltage of the storage element 9 becomes larger than that in the normal state.

  When harmonic superimposition control is performed, the voltage of the storage element 9 gradually decreases. Therefore, the change in the voltage value of the storage element 9 has the same voltage waveform as (a) in the normal state. Therefore, the value of the input voltage of the storage element 9 detected by the input voltage detection unit 7 naturally has the same voltage waveform as (a) in the normal state, provided that the input voltage detection unit 7 performs the voltage detection normally. It should be.

  Therefore, the control unit 3 determines that the detection result of the input voltage detection unit 7 is abnormal depending on whether or not the value of the detection voltage output from the input voltage detection unit 7 has the same voltage waveform as (a) at the normal time. It can be determined whether there is any. That is, the control unit 3 compares the waveform pattern of the detected voltage output from the input voltage detection unit 7 with the voltage waveform pattern of (a) at normal time stored in advance in the memory as a comparison waveform pattern, If the difference between them exceeds the first threshold, it can be determined that the detection result of the input voltage detection unit 7 is abnormal.

In addition, the following example is mentioned as a determination method by the difference between waveform patterns.
(Example 1) The total area of a portion surrounded by two waveform patterns on the graph is obtained from time 0 to time t, and the input voltage is detected when the value of the total area exceeds the first threshold value. It is determined that the detection result of the unit 7 is abnormal. Specifically, for example, the total area of a portion surrounded by the waveform pattern of (a) of FIG. 2 and the waveform pattern of (b) is obtained, and compared with a first threshold.
(Example 2) At two or more preset times from time 0 to time t, the value of the detected voltage output at the corresponding time by the input voltage detection unit 7 and the normal time as the comparison waveform pattern Comparing the voltage value at the corresponding time in the waveform pattern of (a), and if the average value or the maximum value of the differences between the voltage values exceeds the first threshold, the input voltage detection unit It is determined that the detection result of 7 is abnormal.

  The contents of the two cases of FIG. 2 and FIG. 3 described above are summarized as follows. First, as shown in (b) and (c) of FIG. 2, when the detection sensitivity of the input voltage detection unit 7 is in an abnormal state, the sensitivity is different from that in the normal state. For this reason, the detected voltage is recognized to be higher than the actual voltage or lower than the actual voltage. Therefore, the energy consumption of the storage element 9 is controlled to be larger or smaller than that in the normal state. As a result, when the detection sensitivity is high, the waveform of FIG. 2B is obtained. When the detection sensitivity is low, the waveform of FIG. 2C is obtained.

  In addition, since there is no change in the detection result of the input voltage detection unit 7 at the time of the intermediate fixation abnormality, as shown in (d) of FIG. 2, the initial input voltage value remains. Therefore, if the difference between the input voltage value and the initial input voltage value at time t after execution of the harmonic superposition control is less than the second threshold set in advance, the control unit 3 causes the intermediate fixation. It can be determined that it is abnormal.

  Here, time t is a time point when the voltage value of the storage element 9 is 0 in the waveform of (a) at the normal time in FIG. 2, but it is not limited to that case. The time t may be a time when a preset time has elapsed from the time 0, and may be determined arbitrarily as appropriate.

  As described above, when the detection sensitivity abnormality occurs in the input voltage detection unit 7, as shown in FIG. 2, the voltage waveforms (b) and (c) of the storage element 9 at the time of harmonic superposition control are Instead of being identical to the waveform pattern of (a) at the normal time, the waveform is different. Therefore, when the voltage waveform of the storage element 9 at the time of harmonic superposition control does not match the normal time (a) stored in the memory as the comparison waveform pattern, the control unit 3 determines that the input voltage detection is abnormal. I can diagnose.

  Further, as described in FIG. 3, when a voltage corresponding to an offset abnormality higher or lower than that in the normal state is actually applied, the detection voltage of the input voltage detection unit 7 is higher than the voltage detected in the normal state. 3 or lower than the actual voltage, resulting in the waveform of (e) or (g) of FIG.

  On the other hand, when the offset offset detected by the input voltage detector 7 is higher or lower than that in the normal state, the detected voltage of the input voltage detector 7 is recognized higher than the actual voltage detected in the normal state. Or lower than the actual voltage detected at normal times. As a result, the energy consumption of the storage element 9 is controlled to be larger or smaller than that in the normal state. Therefore, the voltage waveform at the time of offset high abnormality is (f) in FIG. 3, and the voltage waveform at the time of offset low abnormality is (h) in FIG.

  At the stage of comparing the detection result with the comparison waveform pattern, the control unit 3 can not determine whether or not a detection offset abnormality has occurred. When the offset abnormality is detected, the control unit 3 determines the waveforms of (e) and (g) when the input voltage detection unit 7 is normal, and when the input voltage detection unit 7 is abnormal (( f) It will compare with the waveform of (h).

  That is, (f) at offset high abnormality becomes (e) the comparison waveform pattern, and (h) at offset low abnormality (h) becomes the comparison waveform pattern. Here, the waveforms of (e) and (g) are different from the voltage waveform (a) at the normal time. Then, (e) to be a comparison waveform pattern is a time waveform different from (f), and similarly, (g) to be a comparison waveform pattern is a time waveform different from (h) ing.

  Therefore, differences occur between (e) and (f) and between (g) and (h). Therefore, the control unit 3 determines that the abnormal state of (f) does not match the comparative waveform pattern of (e), and the abnormal state of (h) does not match the comparative waveform pattern of (g), It can diagnose as input voltage detection abnormality.

  As described above, in order to determine the detection sensitivity abnormality and the detection offset abnormality at the time of harmonic superposition control, the control unit 3 sets an appropriate comparison waveform pattern as a normal value of the input voltage, (a), (e) , (G), it is necessary to select.

  Even when there is no detection offset, the waveform pattern does not necessarily have the waveform pattern of (a), and the waveform pattern changes according to the value of the initial input voltage of the storage element 9 before the start of the harmonic superposition control. Therefore, the initial input voltage of the storage element 9 is changed in advance, and the result of performing the harmonic superposition control for each of the plurality of initial input voltage values is used as a comparison waveform pattern in the memory of the control unit 3 Remember.

  Then, at the time of abnormality diagnosis, control unit 3 selects one comparison waveform pattern from among a plurality of comparison waveform patterns based on the initial input voltage value of storage element 9 and the harmonic superposition control state. Then, the control unit 3 desirably performs abnormality diagnosis of the input voltage detection unit 7 by comparing the waveform pattern of the detected voltage output from the input voltage detection unit 7 with the selected waveform pattern. In addition, when the comparison waveform pattern to select can not be determined to one, the control part 3 may be made to select two or more and to compare one by one.

  As described above, in the first embodiment, a plurality of types of waveform patterns such as (a), (e) and (g) which are comparative waveform patterns are measured for each initial input voltage value, It is stored in the memory of the control unit 3 in advance. Then, at the time of abnormality diagnosis of the input voltage, the control unit 3 selects a corresponding comparison waveform pattern from among the comparison waveform patterns based on the initial input voltage value and the harmonic superposition control state. Furthermore, the control unit 3 determines whether the detection result of the input voltage detection unit 7 is abnormal or not by comparing the waveform of the input voltage detected by the input voltage detection unit 7 with the selected comparison waveform pattern. . Here, the initial input voltage value is a value of the input voltage before execution of the harmonic superposition control detected by the input voltage detection unit 7.

  However, the determination process by the motor control device according to the present invention is not limited to the above method of comparing the waveforms, and may be another method as follows, for example.

  In the case of adopting another method, first, a plurality of comparison waveform patterns are stored in advance in the memory of the motor control device in the same manner as described above. Next, the control unit 3 selects one comparison waveform pattern from among a plurality of comparison waveform patterns based on the initial input voltage value and the harmonic superposition control state. The processing up to here is the same as above.

  Next, control unit 3 estimates the input voltage of storage element 9 after execution of harmonic superposition control, using the selected comparison waveform pattern, based on the initial input voltage value and the harmonic superposition control state. As a method of estimating the input voltage, in the case of obtaining an estimated value of the input voltage value at time t in FIGS. 2 and 3, when harmonic superposition control is performed, the input voltage of the storage element 9 has a waveform for comparison. Since it is estimated that it decreases according to the pattern, if the value of the input voltage of the comparison waveform pattern at time t is extracted, the value becomes an estimated value of the input voltage of the storage element 9 at time t. As described above, assuming that the time after execution of the harmonic superposition control is time t, the value of the input voltage of the comparison waveform pattern corresponding to time t is extracted as the normal value from the comparison waveform pattern. An estimated value of the input voltage of storage element 9 at t can be easily obtained.

  Next, at time t, the control unit 3 causes the input voltage detection unit 7 to detect the value of the input voltage. Then, control unit 3 compares the value of the input voltage detected by input voltage detection unit 7 with the value of the estimated input voltage of storage element 9. Next, the control unit 3 determines that the detection result of the input voltage detection unit 7 is abnormal if the difference between them exceeds the second threshold set in advance.

  As described above, the control unit 3 estimates the value of the input voltage at time t after the execution of the harmonic superposition control based on the initial input voltage value and the harmonic superposition control state before the execution of the harmonic superposition control. Alternatively, the abnormality determination may be performed using the estimation result. Here, time t is a time point when the voltage value of the storage element 9 is 0 in the waveform of (a) at the normal time in FIG. 2, but it is not limited to that case.

  The time t may be a time when a preset time has elapsed from the time 0, and may be determined arbitrarily as appropriate. Further, the time t here may be the same as or different from the time t at the time of the intermediate fixation abnormality determination described above.

  Alternatively, the following method may be used. In the method, a waveform pattern for comparison is not used. Therefore, it is not necessary to particularly provide a storage unit for storing the comparison waveform pattern. In the method, in the abnormality diagnosis mode, first, the input voltage detection unit 7 detects an initial input voltage before execution of the harmonic superposition control. The control unit 3 calculates the waveform pattern in the normal state as the normal value of the input voltage based on the detected initial input voltage or based on the initial input voltage value and the harmonic superposition control state. Calculate using the equation. The waveform pattern at the time of normal corresponds to the detection result according to the passage of time of the input voltage by the input voltage detection unit 7 when the input voltage detection unit 7 executes the harmonic superposition control at the time of normal operation. That is, the waveform pattern in the normal state is the waveform pattern of (a) of FIG. Alternatively, when the waveform pattern in the normal state is determined based on the input voltage before execution of the harmonic superposition control and the detection offset, the waveform pattern in the normal state is the waveform of (e) or (g) in FIG. It becomes a pattern. Next, the control unit 3 diagnoses an abnormality related to the detection result of the input voltage by the input voltage detection unit 7 based on the detection result of the input voltage detected by the input voltage detection unit 7 and the calculated waveform pattern at the normal time. I do. As a determination method using the detection result of the input voltage and the waveform pattern at the normal time, for example, the two are compared and the difference between the two is compared with a threshold. The specific comparison method may be the same as any of the comparison methods using the comparison waveform pattern, the difference between the two may be determined, and the difference may be compared with the threshold value.

  Subsequently, a motor control processing method in the motor control device according to the first embodiment of the present invention will be described. FIG. 4 is a flow chart showing a flow of processing of abnormality diagnosis in motor control according to the first embodiment. That is, FIG. 4 describes the operation of the abnormality diagnosis mode by the control unit 3. In FIG. 4, instead of the method of comparing the waveforms, when the value of the input voltage at time t after the execution of the harmonic superposition control is estimated as a normal value, and the abnormality determination is performed using the estimation result Is shown.

  The abnormality diagnosis in the motor control device according to the first embodiment of the present invention is performed according to the following procedure.

  (Procedure 0): The control unit 3 shifts the control mode from the normal control mode to the abnormality diagnosis mode.

  (Step 1): The control unit 3 controls the power shutoff unit 8 from ON to OFF, and shuts off the current supply from the power supply 1 to the storage element 9 (step S1).

  (Procedure 2): The input voltage detection unit 7 detects the input voltage applied to the storage element 9, and outputs it to the control unit 3 as an initial input voltage value (step S31).

  (Step 3): The control unit 3 controls the switching unit 2 to perform harmonic superposition control to generate a harmonic current (step S21).

  (Step 4): The rotation angle estimation unit 6 acquires the phase current detected by the phase current detection unit 4 (step S22).

  (Procedure 5): The rotation angle estimation unit 6 calculates the estimated value of the rotation angle based on the phase current using the rotation angle estimation method described above, and sends the estimated value of the rotation angle to the control unit 3. It outputs (step S23).

  In steps S22 and S23, the rotation angle estimation unit 6 samples the phase current during a period in which the control unit 3 can determine that the rotation of the motor 5 is stopped, and estimates the rotation angle.

  (Procedure 6): The control unit 3 checks the rotation angle estimated in step S23 continuously at least twice or more, and the rotation angles of a plurality of times are the same, or a third of which the difference is preset. Determine that it is less than the threshold. Next, based on the values of the rotation angles, the control unit 3 determines that the abnormality diagnosis of the input voltage is properly performed even when the rotation of the motor 5 is stopped or the induced voltage is generated. If the motor 5 is rotating at a prescribed low rotation speed, it is determined that "the rotation of the motor 5 is stopped" (step S24).

  (Procedure 7): The control unit 3 generates harmonics based on the initial input voltage value detected in step S31, the harmonic superposition control state of step S21, and the comparison waveform pattern stored in advance in the storage unit. The input voltage of storage element 9 after execution of superposition control is estimated. (Step S32).

  As the input voltage estimation method, as described above, when the input voltage detection unit 7 is in a normal state, harmonic superposition control is performed in advance for each of a plurality of initial input voltage values of the storage element 9, and the result is Is stored in the memory of the motor control device as a waveform pattern for comparison.

  The control unit 3 selects a corresponding comparison waveform pattern from the stored plurality of comparison waveform patterns based on the initial input voltage value acquired in step S31 and the harmonic superposition control state in step S21. At this time, for example, it is assumed that the waveform pattern of (a) at the normal time shown in FIG. 2 or FIG. 3 is selected. In that case, using the waveform pattern of (a), the input voltage value of the storage element 9 at time t after the execution of the harmonic superposition control is estimated from the initial input voltage value and the harmonic superposition control state.

  (Step 8): The control unit 3 acquires the input voltage of the storage element 9 after execution of the harmonic superposition control detected by the input voltage detection unit 7 as an input voltage for abnormality diagnosis (step S33).

  (Procedure 9): The control unit 3 compares the estimation result of the input voltage estimated in step S32 with the input voltage for abnormality diagnosis acquired in step S33, and uses the abnormality diagnosis method of the input voltage described above. Then, an abnormality diagnosis of the input voltage is performed (step S34). Further, at this time, the control unit 3 confirms that the rotation of the motor 5 is in the stop state from the determination result of step S24. That is, when the motor 5 is rotating, the control unit 3 does not perform the abnormality diagnosis in step S34.

  As described above, according to the motor control device according to the first embodiment, even when the power supply 1 of the motor 5 and the motor control device are separated, the input voltage control function for input voltage abnormality diagnosis is separately added. Therefore, input voltage detection abnormality diagnosis can be performed accurately.

  In the first embodiment described above, the method of storing a plurality of comparison waveform patterns in advance in the memory of the motor control device for use in step S32 in the input voltage detection abnormality diagnosis has been described. However, in the case of the input voltage detection abnormality diagnosis of the intermediate fixation of the input voltage detection unit 7, it is not necessary to use the input voltage estimation method.

  Specifically, step S32 is omitted, and the control unit 3 compares the initial input voltage obtained in step S31 with the diagnostic input voltage obtained in step S33 in step S34 to calculate the difference. As a result, when the difference between the initial input voltage and the diagnostic input voltage is less than the second threshold, the control unit 3 can determine that the intermediate fixation is abnormal.

  That is, as described above, the input voltage of the storage element 9 decreases at the time of execution of the harmonic superposition control in step S21. Therefore, the input voltage for abnormality diagnosis obtained in step S33 must be smaller than the initial input voltage value obtained in step S31. Therefore, if the difference between the initial input voltage value at time 0 and the input voltage after execution of the harmonic superposition control at time t is less than the third threshold, control unit 3 determines that the intermediate fixation has occurred. It can be judged as abnormal.

  As described above, in the motor control device according to the first embodiment, the switching unit 2 switches the current application path to the U-phase, V-phase, and W-phase of the motor 5 by switching ON / OFF the switch element. And a phase current detection unit 4 for detecting the phase current of each of the U, V, and W phases, and a three-phase motor 5 including U, V, and W phases. Further, the motor control device estimates a rotation angle of the motor 5 based on the phase current detected by the phase current detection unit 4, and a storage element 9 connected to both ends of the switching unit 2. An input voltage detection unit 7 that detects an input voltage applied to the storage element 9 is provided. The motor control device further includes a power shutoff unit 8 that switches connection / disconnection between the positive terminal of the power supply 1 and the storage element 9. Furthermore, the motor control device includes a control unit 3 that controls the motor 5 by turning on / off the switch element of the switching unit 2. Control unit 3 determines the rotation stop of motor 5 based on the estimated rotation angle obtained by rotation angle estimation unit 6, and when rotation of motor 5 stops, the input of storage element 9 obtained by input voltage detection unit 7 Based on the voltage, make an abnormality diagnosis of the input voltage.

  At this time, the control unit 3 performs harmonic superposition control to turn on / off the switching unit 2 by superimposing harmonic currents in a range in which the motor 5 does not rotate. Thereby, the control unit 3 generates harmonic current in each phase of the motor 5, and the rotation angle estimation unit 6 estimates rotation angle using the phase current on which harmonics are superimposed obtained from the phase current detection unit 4. Do. The control unit 3 determines the stop of the rotation of the motor 5 from the estimated value of the rotation angle obtained by the rotation angle estimation unit 6. Further, at the time of harmonic superposition control, the input voltage after harmonic superposition control is estimated from the initial input voltage value before harmonic superposition control obtained by the input voltage detection unit 7 and the state of harmonic superposition control. The control unit 3 compares the input voltage after execution of the harmonic superposition control detected by the input voltage detection unit 7 with the estimation result of the input voltage, and if the difference between them exceeds the threshold value, Diagnose as input voltage detection error. As described above, according to the present embodiment, in the state where the current supply from the power supply to the storage element 9 is stopped, the harmonic superposition control is performed to reduce the voltage of the storage element 9, thereby making it possible to diagnose abnormality. The detection result of the input voltage of the input voltage detection unit 7 is obtained. As a result, it is not necessary to separately provide an input voltage control function as provided in the conventional device of Patent Document 1, and power consumption can be achieved even when the power supply 1 of the motor 5 and the motor control device are disconnected. While suppressing, it is possible to diagnose correctly the input voltage detection abnormality.

  As described above, in the present invention, each embodiment can be appropriately modified or omitted within the scope of the present invention.

  1 power supply, 2 switching unit, 3 control unit, 4 phase current detection unit, 5 motor, 6 rotation angle estimation unit, 7 input voltage detection unit, 8 power supply shut off unit, 9 electric storage element.

Claims (8)

A phase current detection unit that detects a phase current of each phase of the motor;
A rotation angle estimation unit that calculates an estimated value of the rotation angle of the motor based on the phase current detected by the phase current detection unit;
A switching unit that switches a current conduction path to each phase of the motor;
A storage element connected to both ends of the switching unit,
An input voltage detection unit that detects an input voltage applied to the storage element;
In the normal control mode, switching control of the current application path is performed by switching ON / OFF of the switch element of the switching unit, and in the abnormality diagnosis mode, abnormality diagnosis on the detection result of the input voltage of the input voltage detection unit is performed. , Control unit,
Power supplies connected to both ends of the switching unit and to both ends of the storage element;
And a power cut-off unit connected between the power supply and the storage element to turn off the power supply to the switching unit and the storage element when turned off.
The control unit
In the abnormality diagnosis mode,
In the state where the power supply cutoff unit is switched to the OFF state and the current supply from the power supply to the storage element is stopped, the harmonic superposition control is performed to superimpose the harmonic current of the range in which the motor does not rotate on the motor Generate harmonic currents in each phase of the motor,
The motor performs the harmonic superposition control based on the estimated value of the rotation angle obtained by the rotation angle estimation unit using the phase current superimposed by the harmonics detected by the phase current detection unit. Determine whether or not it is in the rotation stop state,
When it is determined that the motor is in the rotation stop state, the input voltage detected by the input voltage detection unit, and the input when the harmonic superposition control is performed during the normal operation of the input voltage detection unit Performing the abnormality diagnosis on the detection result of the input voltage by the input voltage detection unit based on the normal value of the input voltage detected by the voltage detection unit;
Motor controller. The control unit is configured to stop the rotation of the motor based on the estimated value of the rotation angle, or define a low rotation range defined as a range in which the abnormality diagnosis is correctly performed even if an induced voltage is generated. When the motor is rotating by a number, it is determined that the motor is in a rotation stop state,
The motor control device according to claim 1. The control unit controls a duty ratio of the switching unit when performing the harmonic superposition control based on the input voltage detected by the input voltage detection unit.
The motor control device according to claim 1. The control unit
When the input voltage detection unit executes the harmonic superposition control during the normal operation as the normal value of the input voltage, the detection result according to the passage of time of the input voltage by the input voltage detection unit is used as a comparison waveform pattern Has a storage unit to be stored in advance
In the abnormality diagnosis mode, the abnormality diagnosis related to the detection result of the input voltage by the input voltage detection unit is based on the detection result of the input voltage detected by the input voltage detection unit and the comparison waveform pattern. Do,
The motor control device according to any one of claims 1 to 3. The control unit is configured to:
And comparing a waveform pattern for comparison stored in the storage unit corresponding to the initial input voltage based on an initial input voltage before execution of the harmonic superposition control detected by the input voltage detection unit;
If the absolute value of the difference between the two exceeds the first threshold value based on the comparison result of the waveform pattern of the input voltage detected by the input voltage detection unit and the extracted waveform pattern for comparison. Determining that the detection result of the input voltage of the input voltage detection unit is abnormal;
The motor control device according to claim 4. The control unit is configured to:
Based on an initial input voltage before execution of the harmonic superposition control detected by the input voltage detection unit, a waveform pattern for comparison stored in the storage unit corresponding to the initial input voltage is extracted and extracted The input voltage at time t after a predetermined time has elapsed since the start of execution of the harmonic superposition control is extracted as an estimated value from the compared waveform pattern.
The input voltage detection unit compares the input voltage detected at the time t with the estimated value, and if the absolute value of the difference between the two exceeds the second threshold, the input voltage of the input voltage detection unit Determine that the detection result of is abnormal,
The motor control device according to claim 4. The control unit is configured to:
The input voltage detection unit executes the harmonic superposition control during normal operation based on the initial input voltage before execution of the harmonic superposition control detected by the input voltage detection unit as the normal value of the input voltage Calculating a normal waveform pattern corresponding to the detection result of the input voltage with the passage of time by the input voltage detection unit in the case where
Regarding the detection result of the input voltage by the input voltage detection unit based on the detection result of the input voltage detected by the input voltage detection unit and the calculated waveform pattern at the normal time in the abnormality diagnosis mode Perform the abnormality diagnosis
The motor control device according to any one of claims 1 to 3. The controller is further configured to:
Storing an initial input voltage before execution of the harmonic superposition control detected by the input voltage detection unit;
The difference between the input voltage detected by the input voltage detection unit and the initial input voltage at time t after a predetermined time has elapsed since the start of execution of the harmonic superposition control is less than a third threshold And if the detection result of the input voltage detection unit is abnormal,
The motor control device according to any one of claims 1 to 7.

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