JP2010220384A - Device for control of rotary electric machine - Google Patents

Abstract

An object of the present invention is to make it easier to determine the phase loss of an inverter connected to a rotating electrical machine in a rotating electrical machine control device.
A rotating electrical machine control device 40 acquires an evaluation current value having a predetermined content for detecting a phase failure, compares it with an evaluation current threshold value, and the acquired evaluation current value is an evaluation current. A primary determination processing unit 42 that determines that there is a possibility of phase failure when the threshold value is not exceeded but is greater than a normal value, and the current value that flows through the rotating electrical machine is increased when it is determined that there is a possibility of phase loss. Current increase processing unit 44 to be evaluated, the evaluation current value under the current increase state is acquired, the acquired evaluation current value is compared with the evaluation current threshold, and the evaluation current value exceeds the evaluation current threshold. And an open phase determination processing unit 46 that determines that a phase failure has occurred.
[Selection] Figure 1

Description

  The present invention relates to a rotating electrical machine control device, and more particularly, to a rotating electrical machine control device for a rotating electrical machine to which an inverter is connected.

  An inverter is connected to the rotating electrical machine for driving. An inverter is a circuit that combines a plurality of switching elements and diodes. An upper arm switching element and an upper arm diode connected in parallel are used as an upper arm element, and a lower arm switching element and a lower arm diode are connected in parallel. As an arm element, these are connected in series and connected in parallel in a plurality of phases as a unit of one phase. For example, in a three-phase AC rotating electric machine, each phase arm in which an upper arm element and a lower arm element are connected in series corresponding to each phase of U phase, V phase, and W phase is connected in parallel for three phases. Inverter is used.

  Thus, since two switching elements are used for each phase, the inverter connected to the three-phase rotating electrical machine includes six switching elements. If a malfunction occurs in the operation of one of these switching elements, the positive side or the negative side of the alternating current waveform of the phase including the switching element is missing, resulting in a so-called phase failure. When a phase failure occurs, the rotating electrical machine operation is not normal, and it is necessary to detect the phase failure.

  For example, Patent Document 1 discloses that, as a control device for a three-phase AC motor, the switching element of the drive inverter has failed, the current of each phase is integrated for each phase, and the value for one cycle of motor rotation is correct. Whether the upper arm element is open or the lower arm element is open is determined based on whether or not it is negative.

  In Patent Document 2, as a failure detection device when a motor malfunction occurs, each phase current is measured, and the ratio of the maximum value between them with respect to the minimum value between them is expressed as a current ratio X. It is stated that X is approximately 1 in a normal state and X is greater than 1 in the case of a failure. In addition, it is pointed out that X is larger in the case of phase loss due to poor connection of energized wires than in the case where current flows in all phases due to defective inverter circuits and the balance is lost.

  Patent Document 3 discloses that each phase current value when a current of another phase is also obtained by two-phase current detection, as a method of detecting a phase failure in a power conversion device that also obtains a current of another phase by two-phase current detection. In addition, it is described that values obtained by adding the absolute values of the instantaneous values of the respective phase currents thus obtained for a predetermined period are obtained and compared with each other. If the inverter output is normal, the three-phase current is balanced, and the sum of these absolute values will be almost the same value. Since it collapses, there is a difference between the added values of the absolute values. Therefore, it is described that the presence / absence of a missing phase is determined based on the magnitude of the difference.

  In Patent Document 4, as a motor control system capable of detecting a phase loss, when a d-axis current Id and a q-axis current are viewed, Id = 0 in a normal state and Iq is a constant value of a command value. It is stated that the absolute value of Id is a waveform distorted around 0, the absolute value of Iq is a waveform distorted around the Iq command value, and the ratio takes a certain value instead of 0. Further, it is stated that it is possible to detect an open phase when the absolute value of Id exceeds a certain threshold and the ratio between the Id absolute value and the Iq absolute value is within a certain range.

JP 2005-94873 A JP 2005-181167 A JP 2007-89261 A JP 2008-92690 A

  As described above, in the prior art, it is stated that in the rotating electrical machine to which the inverter is connected, the phase loss determination is performed based on various evaluations regarding the current flowing in each phase of the rotating electrical machine. That is, for various evaluations regarding the current flowing in each phase, as well known, for each phase current described in Patent Document 1, in addition to a method using an offset current in which the sum of the phase currents deviates from zero, Integrated value, ratio of maximum value and minimum value for each phase current described in Patent Document 2, addition of absolute value of instantaneous value of each phase current described in Patent Document 3, described in Patent Document 4 There are the absolute value of the Id current and the absolute value of the Iq current.

  In these methods, as described in each patent document, it is possible to determine whether or not there is an open phase by comparing the obtained evaluation value with the threshold value by providing a threshold value for the evaluation value relating to the current. Thus, in the method using the threshold value, if the original current value is small, the difference from the threshold value is also small, and it may be difficult to determine the missing phase.

  An object of the present invention is to provide a rotating electrical machine control device capable of further facilitating the phase loss determination.

  A rotating electrical machine control device according to the present invention is a device that detects an open-phase failure that is a failure related to a switching element that constitutes an inverter connected to the rotating electrical machine, and the current flowing in each phase of the rotating electrical machine is predetermined. The obtained evaluation current value is compared with a predetermined evaluation current threshold, and the obtained evaluation current value does not exceed the evaluation current threshold but is larger than the normal value. The primary evaluation means that determines that there is a possibility of phase loss sometimes, and the current value that flows through the rotary electric machine under constant power of the rotating electric machine when the primary evaluation means determines that there is a possibility of phase loss. The current increase means for increasing and the evaluation current value under the current increase state are obtained, and the obtained evaluation current value is compared with the evaluation current threshold value. It is a failure A phase loss determining means for disconnection, characterized in that it comprises a.

  In the rotating electrical machine control apparatus according to the present invention, the current increasing means is preferably system voltage decreasing means for decreasing the inverter system voltage to increase the drive current value.

  Further, in the rotating electrical machine control device according to the present invention, the rotating electrical machine includes two types of power generation and traveling, and the primary evaluation means further determines the possibility of phase loss when it is determined that phase loss is possible. It is determined whether there is a rotating electric machine for power generation or a rotating electric machine for traveling, and the current increasing means reduces the torque command of the rotating electric machine for traveling if there is a possibility of phase failure in the rotating electric machine for power generation If the torque command value of the rotating electrical machine for power generation is increased and there is a possibility of phase failure in the rotating electrical machine for traveling, the torque command value of the rotating electrical machine for power generation is decreased and the torque of the rotating electrical machine for traveling is reduced. A torque command changing means for increasing the command value is preferable.

  With the above configuration, the rotating electrical machine control device acquires an evaluation current value having a predetermined content for the current flowing through each phase of the rotating electrical machine, and compares the acquired evaluation current value with a predetermined evaluation current threshold value. When the acquired evaluation current value does not exceed the evaluation current threshold but is larger than the normal value, it is determined that there is a possibility of phase failure, and the current value flowing through the rotating electric machine under constant power of the rotating electric machine is determined. increase. As a result, the evaluation current value can also be increased, the comparison with the evaluation current threshold is facilitated, and the accuracy of the phase loss determination is improved.

  Also, in the rotating electrical machine control device, the inverter system voltage is reduced to increase the drive current value, so that the evaluation current value can also be increased, and the comparison with the evaluation current threshold becomes easy, and the phase loss determination Improves accuracy. Specifically, when the system voltage is generated by boosting the voltage of the power storage device, the system voltage can be lowered by suppressing the boosting.

  In addition, in a rotating electrical machine control device including two types of rotating electrical machines for power generation and traveling, it is determined whether the rotating electrical machine for power generation or the rotating electrical machine for traveling has a possibility of phase loss. When there is a possibility of phase failure in the rotating electrical machine, the torque command value of the rotating electrical machine for power generation is increased by decreasing the torque command of the rotating electrical machine for traveling, and there is a possibility of phase failure in the rotating electrical machine for traveling At this time, the torque command value of the rotating electrical machine for power generation is decreased to increase the torque command value of the rotating electrical machine for traveling. When the torque command is increased, the rotating electrical machine drive current is also increased. Accordingly, the evaluation current value can be increased, the comparison with the evaluation current threshold is facilitated, and the accuracy of the phase loss determination is improved.

It is a figure explaining the structure of the rotary electric machine control apparatus of embodiment which concerns on this invention. It is a figure explaining the mode of a change of the phase current waveform when an open phase occurs. 5 is a flowchart illustrating a procedure for determining a phase failure in the embodiment according to the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a vehicle on which a rotating electrical machine is mounted will be described as an example in which the rotating electrical machine control device is used.

  In addition, this vehicle will be described as using two motor / generators having a motor function and a generator function as a rotating electric machine. However, this is an example, and one rotating electric machine having only a motor function is used. One rotating electric machine having only a generator function may be used. Three or more motor generators may be used. As will be described below, when the current can be increased by boost control, the present invention can be applied regardless of the number of rotating electrical machines, whether it is one or more. In addition, as a vehicle, it is good also as what mounts an engine other than a rotary electric machine.

  In the following, a configuration including a power storage device, a system main relay, a voltage converter, an inverter, and a smoothing capacitor will be described as a power supply circuit connected to the rotating electrical machine. However, this is an example and includes other elements. It is good. For example, a low voltage DC / DC converter can be included. In addition to the power storage device, a fuel cell may be included as a power source.

  Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted. In the description in the text, the symbols described before are used as necessary.

  FIG. 1 is a diagram showing the configuration of a rotating electrical machine control system 8 for a rotating electrical machine mounted on a vehicle. The rotating electrical machine control system 8 includes rotating electrical machines 30 and 32, a power supply circuit 10 connected to the rotating electrical machines 30, and a rotating electrical machine control device 40 that controls the operation of these components as a whole.

  The rotating electrical machine (MG1) 30 and the rotating electrical machine (MG2) 32 are motor generators (MG) mounted on the vehicle, and function as motors when electric power is supplied from the power storage device 12 included in the power supply circuit 10. However, this is a three-phase synchronous rotating electric machine that functions as a generator when driven by an engine (not shown) or when the vehicle is braked.

  The rotating electrical machine (MG1) 30 and the rotating electrical machine (MG2) 32 are motor generators (M / G) mounted on the vehicle, and function as a motor when electric power is supplied, and function as a generator during braking. This is a three-phase synchronous rotating electric machine. In the example of FIG. 1, one of the two rotating electric machines 30 and 32 is used as a generator for charging the power storage device 12, and the other is used mainly as a drive motor for driving the vehicle.

  That is, as described above, one rotating electrical machine (MG1) 30 is driven by an engine (not shown) to be used as a generator, and the generated electric power is used to supply the power storage device 12. Further, the other rotating electrical machine (MG2) 32 is used for running the vehicle, receives power from the power storage device 12 during power running, functions as a motor to drive the vehicle axle, and functions as a generator during braking. Thus, the regenerative energy can be recovered and supplied to the power storage device 12.

  Thus, since the two rotating electrical machines 30 and 32 are in principle a motor / generator having a common configuration, their functions can be distributed and used for power generation and travel as described above. It is also possible to adjust the output torque between them using an appropriate power distribution mechanism. For example, it is possible to increase the torque command of the rotating electrical machine 32 while reducing the torque command of the rotating electrical machine 30 while keeping the overall output power the same.

  The power supply circuit 10 is a circuit connected to the rotating electrical machines 30 and 32, and supplies electric power to the rotating electrical machines 30 and 32 when they function as drive motors, or the rotating electrical machines 30 and 32 function as generators. Sometimes, it has a function of receiving the regenerative power and charging the power storage device 12. The power supply circuit 10 includes a power storage device 12 that is a secondary battery, a system main relay 14, a smoothing capacitor 16 on the power storage device 12 side, a voltage converter 18, a smoothing capacitor 20 on the inverters 22 and 24 side, and an inverter 22. , 24.

  As the power storage device 12, for example, a lithium ion assembled battery or a nickel hydride assembled battery having a terminal voltage of about 200 V, a capacitor, or the like can be used.

  The system main relay 14 is a relay that can be switched off and switched so that the high-voltage power supply system can be disconnected from the rotating electrical machines 30 and 32 when the rotating electrical machines 30 and 32 are stopped. is there.

  The voltage converter 18 is a circuit having a function of boosting the voltage on the power storage device 12 side to, for example, about 650 V using the energy storage action of the reactor, and is also called a boost converter. Note that the voltage converter 18 has a bidirectional function, and when the electric power from the inverters 22 and 24 side is supplied to the power storage device 12 side as charging power, the high voltage on the inverters 22 and 24 side is a voltage suitable for the power storage device 12. It also has an action to lower the blood pressure.

  The step-up / step-down voltage of the voltage converter 18 has a function of supplying an optimum voltage to the inverters 22 and 24 according to the operation status of the rotating electrical machines 30 and 32. The voltage between the positive and negative buses of the inverters 22 and 24 is sometimes called a system voltage. In this sense, the voltage converter 18 changes the system voltage according to the operating conditions of the rotating electrical machines 30 and 32. It has the function to do. For example, when operating the rotating electrical machines 30 and 32 at high output and high rotation, the system voltage is increased to increase the system voltage, and when energy saving operation is performed, the system voltage is decreased to decrease. When the voltage is raised and lowered with constant power, the magnitude of the current supplied to the inverters 22 and 24 can be adjusted.

  The smoothing capacitor 16 on the power storage device 12 side and the smoothing capacitor 20 on the inverters 22 and 24 side have a function of suppressing and smoothing fluctuations in voltage and current between the positive electrode bus and the negative electrode bus on the respective sides.

  The inverters 22 and 24 are configured to include a plurality of switching elements that operate under the control of the rotating electrical machine control device 40, and are circuits that perform power conversion between AC power and DC power. As shown in FIG. 1, the (MG1) inverter 22 is connected to the rotating electrical machine (MG1) 30, and the (MG2) inverter 24 is connected to the rotating electrical machine (MG2) 32.

  When the rotating electrical machine (MG1) 30 is caused to function as a generator, the inverter 22 converts the AC three-phase regenerative power from the rotating electrical machine (MG1) 30 into DC power and supplies it as a charging current to the power storage device 12 side. Has AC / DC conversion function. Further, the inverter 24 connected to the rotating electrical machine (MG2) 32 converts DC power from the power storage device 12 side into AC three-phase driving power when the vehicle is powered, and supplies the rotating electrical machine (MG2) 32 as driving power. An orthogonal conversion function to be supplied, and an AC / DC conversion function to convert AC three-phase regenerative power from the rotating electrical machine (MG2) 32 into DC power and supply it as a charging current to the power storage device 12 when the vehicle is braked. Have.

  The inverters 22 and 24 are circuits in which a plurality of switching elements and diodes are combined. An upper arm switching element is connected in reverse parallel to the upper arm switching element, and the lower arm switching element is inverted. A device connected in parallel is a lower arm element, and a device in which these devices are connected in series is used as a unit of one phase and connected in parallel in a plurality of phases. For example, in a three-phase AC rotating electric machine, each phase arm in which an upper arm element and a lower arm element are connected in series corresponding to each phase of U phase, V phase, and W phase is connected in parallel for three phases. Inverter is used.

  For example, wiring drawn from the connection point between the upper switching element and the lower switching element of the U-phase arm is connected to the U-phase coil of the rotating electrical machine. Similarly, the wiring drawn from the connection point between the upper switching element and the lower switching element for the V-phase arm is connected to the V-phase coil of the rotating electrical machine, and the connection between the upper switching element and the lower switching element for the W-phase arm is performed. The wiring drawn from the point is connected to the W-phase coil of the rotating electrical machine. In the example of FIG. 1, in the rotating electrical machines 30 and 32, each phase coil is commonly connected at the neutral point, and therefore the wiring drawn from each phase arm of the inverters 22 and 24 is the neutral point of each coil. It will be connected to the terminal that is not.

  In this way, wiring is performed from the respective phase arms of the inverters 22 and 24 to the respective phase coils of the rotating electrical machines 30 and 32. Through this wiring, a drive current is supplied from the inverter side to the rotating electrical machine side during driving of the rotating electrical machine, and a generated current is supplied from the rotating electrical machine side to the inverter side during regeneration. As described above, the current flowing in each phase of the rotating electrical machines 30 and 32 passes through the wirings connecting the inverters 22 and 24 and the rotating electrical machines 30 and 32.

  The current flowing through each of the three wires connecting the inverter 22 and the rotating electrical machine 30 is detected as a current flowing through each phase of the rotating electrical machine 30 using an appropriate current detection sensor and transmitted to the rotating electrical machine control device 40. . Similarly, the current flowing through each of the three wirings connecting the inverter 24 and the rotating electrical machine 32 is detected as a current flowing through each phase of the rotating electrical machine 32 using an appropriate current detection sensor, and is sent to the rotating electrical machine control device 40. Is transmitted.

  In the example of FIG. 1, since each of the inverters 22 and 24 connected to the rotating electrical machines 30 and 32 that are three-phase rotating electrical machines uses two switching elements for each phase, there are 6 switchings for each of the inverters 22 and 24. An element is included. If a malfunction occurs in the operation of one of these switching elements, the positive side or the negative side of the alternating current waveform of the phase including the switching element is missing, resulting in a so-called phase failure.

FIG. 2 shows changes in the phase current waveform before and after the phase failure occurs. The figure on the left is a phase current waveform in a normal state, and is a sine wave symmetrical on the plus side and minus side above and below current = 0. The diagram on the right side shows the phase current waveform when an open-phase failure occurs. In this example, the negative current does not flow, and the current flows only in the positive cycle of current = 0. In FIG. 2, the time average of the phase current waveform is shown as I ₀ , but in the normal state, I ₀ = 0, but when a phase loss occurs, I ₀ does not become zero, but an offset value It becomes.

  As the phase failure, there are a case where the switching element itself malfunctions and a case where the control signal supplied from the rotating electrical machine control device 40 to the switching element is defective. An example of the latter is a case where a disconnection or the like occurs in the control signal line from the rotating electrical machine control device 40 to each switching element.

  Thus, in the phase failure, the plus or minus side of the corresponding phase current is missing from the current flowing through each phase of the rotating electrical machine. Further, as described above, the phase coils of the rotating electrical machines 30 and 32 are commonly connected at the neutral point, so that the phase currents flowing through the rotating electrical machines are (U-phase current value + V-phase current value + W-phase current value). = 0, but this balance is lost when a phase failure occurs. Therefore, (U-phase current value + V-phase current value + W-phase current value) = 0 is not satisfied, and the waveform of the phase current other than the phase current in which the phase failure has occurred is also distorted.

  As described above, when a phase failure occurs, the waveform of the current flowing in each phase of the rotating electrical machine changes from the normal state, and the operation of the rotating electrical machine becomes abnormal. Therefore, it is necessary to detect the phase failure. .

  The rotating electrical machine control device 40 has a function of controlling the operation of the rotating electrical machines 30 and 32 mounted on the vehicle as a whole through the control of the power supply circuit 10 and the like. In particular, here, the inverter 22 and 24 have a function of performing control for effectively detecting a phase failure. The rotating electrical machine control device 40 can be configured by a computer or the like suitable for mounting on a vehicle. The function of the rotating electrical machine control device 40 can be a part of the function of another on-vehicle computer. For example, the function of the rotating electrical machine control device 40 can be given to a hybrid ECU or the like that controls the entire vehicle.

  The rotating electrical machine control device 40 acquires an evaluation current value having a predetermined content in order to detect a phase failure, compares it with a predetermined evaluation current threshold, and the acquired evaluation current value is the evaluation current threshold. When it is determined that there is a possibility of phase loss by the primary determination processing unit 42 that determines that there is a possibility of phase loss when it does not exceed the normal value but is larger than the normal value, The current increase processing unit 44 that increases the current value flowing through the rotating electrical machine under the constant power of the rotating electrical machine, the evaluation current value under the current increasing state is acquired, and the acquired evaluation current value and the evaluation current threshold value are obtained. In comparison, the phase loss determination processing unit 46 determines that a phase failure has occurred when the evaluation current value exceeds the evaluation current threshold.

  Such a function can be realized by executing software, and specifically, can be realized by executing a rotating electrical machine control program. Some of these functions may be realized by hardware.

The operation of the above configuration, particularly each function of the rotating electrical machine control device 40, will be described in detail with reference to the flowchart of FIG. FIG. 3 shows a procedure for effectively detecting an open phase failure, and each procedure corresponds to each processing procedure of the open phase failure detection portion in the rotating electrical machine control program.
When the rotating electrical machine control system 8 is started and the rotating electrical machine control program is started, each phase current value of the rotating electrical machines 30 and 32 is acquired. As described above, each phase current value is acquired by detecting the current value flowing through each of the three wires connecting the inverters 22 and 24 and the rotating electrical machines 30 and 32 with an appropriate current detection sensor or the like, and rotating the value. This is performed by being transmitted to the electric machine control device 40.

  Using each transmitted phase current value, an evaluation current value for determining a phase failure is obtained. When a phase failure occurs, each phase current waveform changes as shown in FIG. 2. Therefore, the contents of the evaluation current are determined in advance by a method capable of detecting the change in each phase current waveform. Various contents of the evaluation current can be used as shown in each of the above patent documents. Here, as shown in FIG. 2, in the normal state, the time average of each phase current is zero, whereas when a phase failure occurs, the time average of the phase current does not become zero, but the offset current The following explanation will be made on the assumption that it becomes a value. Of course, it is good also as what judges a phase failure using the evaluation current of contents other than this.

  In this way, for the detection of phase failure, if the offset current value, which is the value obtained by averaging each phase current over time, is used as the evaluation current value, the presence or absence of the phase failure is determined by the offset current value that is the evaluation current value. Can be determined by whether or not exceeds a predetermined evaluation current threshold.

  In FIG. 3, first, it is determined whether or not there is a possibility of phase loss using each phase current value (S10). This step is executed by the function of the primary determination processing unit 42 of the rotating electrical machine control device 40. The reason why the primary determination is made is that when the offset current value and the evaluation current threshold are compared, if the original phase current value is small, the offset current value also becomes a small value. This is because there is a possibility.

For example, in the example of FIG. 2, the offset current value I ₀ = 0 in the normal state, but the offset current value I ₀ does not become zero when a phase loss occurs. Its magnitude is in accordance with the original peak value of the phase current. On the other hand, the evaluation current threshold I _th is set to a predetermined value in advance with an appropriate margin in consideration of variations in current detection sensors, external noise, and the like. As described above, the evaluation current threshold I _th is fixed to a predetermined value in advance. Therefore, when the original phase current is large, the offset current value I ₀ is also sufficiently large, and the comparison with the evaluation current threshold I _th is easy. However, when the original phase current is small, the offset current value I ₀ also decreases accordingly, which makes it difficult to compare with the fixed value evaluation current threshold I _th .

  Since the magnitude of the original phase current is the magnitude of the current flowing in each phase of the rotating electrical machines 30 and 32, it depends on the magnitude of the system voltage of the inverters 22 and 24. In addition, since the magnitude of the original phase current is also the magnitude of the drive current corresponding to the required torque for the rotating electrical machines 30 and 32, it also depends on the torque command value for the rotating electrical machines 30 and 32. For example, when the torque command value for the rotating electrical machines 30 and 32 is small, the system voltage of the inverters 22 and 24 is also set low, and the peak value of each phase current is also small.

Judgment of the possibility of phase loss is performed when there is a possibility of phase loss when the evaluation current value obtained from each phase current value is less than the evaluation current threshold value but is larger than the evaluation current value in the normal state. It is. Decisions are made individually for all phase currents. In the example of FIG. 2, the evaluation current value in the normal state is I ₀ = 0, and the evaluation current threshold I _th is a value larger than zero in consideration of noise and the like. Therefore, when the actually obtained evaluation current value I ₀ is greater than zero but less than I _th , it can be determined that there is a possibility that it is not possible to conclude that a phase failure has occurred.

  If the determination in S10 is affirmed in FIG. 3, it is next determined whether or not the rotating electrical machine control system 8 is boosting (S12). During boosting, the voltage converter 18 performs a boosting operation and supplies the inverters 22 and 24 with a boosted voltage higher than the supply voltage of the power storage device 12. Therefore, the system voltage of inverters 22 and 24 is higher than the terminal voltage of power storage device 12. Boosting is performed when the rotating electrical machines 30 and 32 have a high output, for example, and no boosting is performed when the rotating electrical machines 30 and 32 have a low output.

  If the determination is affirmative in S12, the boosted voltage is temporarily reduced to determine a phase failure (S14). At this time, it is possible to increase the supply current to the rotating electrical machines 30 and 32 by reducing the boost, assuming that the boost is reduced under constant power. Steps S12 and S14 are executed by the function of the current increase processing unit 44 of the rotating electrical machine control device 40 together with steps S16, S18, and S20 described later.

Under this way increased phase current again, evaluation current value is acquired, whether rated current threshold I _th or more is judged (S22). For example, when the phase current increases by a factor of 1.5, the offset current value I _0, which is the evaluation current value, also increases by a factor of 1.5, making comparison with the evaluation current threshold I _th easy.

Therefore, when it is determined that the evaluation current value I ₀ is equal to or greater than the evaluation current threshold I _th, it is determined for the first time that a phase failure has occurred (S24). This process is executed by the function of the phase loss determination processing unit 46 of the rotating electrical machine control device 40. When it is determined that the phase failure is present, the rotating electrical machine control device 40 performs an abnormality handling process. For example, an abnormal signal is output, and in some cases, the operation of the rotating electrical machines 30 and 32 is stopped.

  If the determination in S24 is negative, it is determined that there is no open-phase failure, so the temporary boost reduction is canceled and the original boost state is restored, and then the process returns to S10. Returning to S10, the above steps are repeated at an appropriate monitoring sampling interval.

  The determination may be denied in S12. For example, the torque command value for the rotating electrical machines 30 and 32 is small and there is no need to increase the pressure. Further, although the determination is affirmed in S12 and the process proceeds to S14, there is a case where the current cannot be sufficiently increased even if the boosting is reduced to the limit because the original boosting degree is low.

  In these cases, it is determined on which side of the rotating electrical machines 30 and 32 there is a possibility of phase loss (S16). The determination of the possibility of phase loss in S10 is performed for each of the three phases of the rotating electrical machine (MG1) 30 and each of the three phases of the rotating electrical machine (MG2) 32. I know if there is.

  When there is a possibility of phase loss for any phase of the rotating electrical machine (MG1) 30, the torque command value for the rotating electrical machine (MG2) 32 is temporarily reduced, and the rotating electrical machine (MG1) is set to cope with this. ) The torque command value of 30 is increased (S18). The term “temporary” is used to determine an open-phase failure as in the case of the temporary step-up in S12.

  Further, the reduction of the torque command value for the rotating electrical machine (MG2) 32 and the increase of the torque command value of the rotating electrical machine (MG1) 30 do not change the rotating electrical machine drive state required as a whole of the rotating electrical machine control system 8 as much as possible. It is preferable to crack the tail. For example, the sum of the output torque of the rotating electrical machine (MG1) 30 and the output torque of the rotating electrical machine (MG2) 32 is set to the same condition, or the output power of the rotating electrical machine (MG1) 30 and the rotating electrical machine (MG2) 32 It is preferable that the sum of the output powers of

  On the other hand, when there is a possibility of phase loss for any phase of the rotating electrical machine (MG2) 32, the torque command value for the rotating electrical machine (MG1) 30 is temporarily reduced, and the rotating electrical machine is adapted to cope with this. (MG2) The torque command value of 32 is increased (S20).

  In this way, by utilizing the fact that the rotating electrical machine control system 8 includes two independently controllable rotating electrical machines 30 and 32, each flow that flows to the rotating electrical machine side where there is a possibility of phase loss even when S12 is denied. The magnitude of the phase current can be increased. After the processes of S18 and S20, the process proceeds to S22 described above, and a determination is made as to whether or not there is a phase failure.

  In this way, when the evaluation current value for determining the open phase failure is a small value depending on the operating state of the rotating electrical machine control system 8, each phase current flowing through the rotating electrical machine is temporarily increased, and the open phase failure is determined. The detectability of determining whether or not there is a failure can be improved. This can improve the accuracy of the determination of the phase failure.

  The rotating electrical machine control apparatus according to the present invention can be used for determining a phase failure in a system in which an inverter and a rotating electrical machine are connected.

  8 rotating electrical machine control system, 10 power supply circuit, 12 power storage device, 14 system main relay, 16, 20 smoothing capacitor, 18 voltage converter, 22, 24 inverter, 30, 32 rotating electrical machine, 40 rotating electrical machine control device, 42 primary Determination processing unit, 44 Current increase processing unit, 46 Phase loss determination processing unit.

Claims (3)

A device for detecting an open phase failure that is a failure related to a switching element that constitutes an inverter connected to a rotating electrical machine,
Means for obtaining an evaluation current value of a predetermined content for the current flowing in each phase of the rotating electrical machine;
The acquired evaluation current value is compared with a predetermined evaluation current threshold, and it is determined that there is a possibility of phase loss when the acquired evaluation current value does not exceed the evaluation current threshold but is larger than a normal value. Next evaluation means,
Current increasing means for increasing a current value flowing through the rotating electrical machine when the primary evaluation means determines that there is a possibility of phase loss;
The evaluation current value under the current increase state is acquired, the acquired evaluation current value is compared with the evaluation current threshold, and when the evaluation current value exceeds the evaluation current threshold, it is determined that a phase failure has occurred. Phase judgment means,
A rotating electrical machine control device comprising: In the rotating electrical machine control device according to claim 1,
The rotating electrical machine control device characterized in that the current increasing means is a system voltage reducing means for increasing the drive current value by reducing the system voltage of the inverter. In the rotating electrical machine control device according to claim 1,
The rotating electrical machine includes two types for power generation and traveling,
When it is determined that there is a possibility of phase loss, the primary evaluation means determines whether there is a possibility of phase loss, whether it is a rotating electrical machine for power generation or a rotating electrical machine for traveling,
When there is a possibility of phase failure in the rotating electric machine for power generation, the current increasing means decreases the torque command of the rotating electric machine for traveling to increase the torque command value of the rotating electric machine for power generation, and When there is a possibility of phase failure, the rotating electrical machine control device is a torque command changing means that decreases the torque command value of the rotating electrical machine for power generation and increases the torque command value of the rotating electrical machine for traveling .

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