JP2009254150A - Step-up converter control device for electric vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a step-up converter control device for an electric vehicle that specifies the cause of abnormality detection by identifying the abnormality detection of an atmospheric-pressure sensor. <P>SOLUTION: The step-up converter control device 10 for an electric vehicle is provided with a step-up converter 12, an atmospheric-pressure sensor 11 stored inside a waterproof case 14 in which a ventilation filter 16 is mounted in a through-hole 15, a step-up converter control part 17 for restricting the voltage step-up by the step-up converter 12 on the basis of a measured value of the atmospheric-pressure sensor 11, and an abnormality-detection determination device 18. The abnormality-detection determination device 18 has an abnormality determination part 19 for determining that the measured value of the atmospheric-pressure sensor 11 is abnormal, a factor decision part 21 that redetermines whether or not the measured value of the atmospheric-pressure sensor is abnormal after the elapse of a prescribed standby time so as to decide whether or not the abnormality of the measured value is an abnormality caused by the ventilation filter 16, and a standby-time calculation part 20 for calculating the prescribed standby time. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a boost converter control device for an electric vehicle, and more particularly, to a boost converter control device for an electric vehicle including a boost control device that controls boosting by a boost converter based on a measured value of an atmospheric pressure sensor.

  An electric vehicle such as a hybrid vehicle is equipped with an electric device that drives or supplies a high voltage, such as an electric motor that drives the vehicle or a boost converter that boosts a power supply voltage. In order to prevent a short circuit (short circuit), these electrical devices are provided with insulation measures such as providing a certain interval between conductors or insulatingly covering the conductors. When such an electric vehicle travels in a high altitude, the atmospheric pressure is low and the dielectric constant of air rises in the high altitude, so that the amount of partial discharge between the conductors may increase and so-called insulation breakdown may occur. Therefore, the electric vehicle is equipped with a control device that sets the voltage value of the electric device according to the atmospheric pressure.

  As said control apparatus, the control apparatus of the moving body currently disclosed by patent document 1 is mentioned, for example. The control device of Patent Document 1 includes a means for detecting atmospheric pressure and a control means for controlling the electric motor. The control means includes an electric motor and an electric motor according to the atmospheric pressure detected by the atmospheric pressure sensor. Means for setting a voltage value to be supplied to the electric motor and means for controlling the electric motor based on the set voltage value are included. In Patent Document 1, an atmospheric pressure sensor is used as a means for detecting the atmospheric pressure, and the boosted voltage output from the converter is the maximum value of the boosted voltage stored in advance based on the measured value of the atmospheric pressure sensor. Is set as the maximum value, that is, boosting by the boosting converter is controlled based on the measured value of the atmospheric pressure sensor.

  In general, as described in Patent Document 2, the atmospheric pressure sensor does not function when the sensor element portion is wetted with water. Therefore, the atmospheric pressure sensor is stored in a waterproof case in which a water repellent ventilation filter is attached to the through hole. And installed in the engine room. Therefore, Patent Document 2 describes that atmospheric pressure outside the case is introduced to the atmospheric pressure sensor via a water-repellent ventilation filter.

JP 2006-288170 A JP 2001-296195 A

  According to the control device of Patent Document 1, even when the electric vehicle travels in a high altitude with low atmospheric pressure, it is possible to ensure the insulation performance of the electric device by setting the voltage value based on the measured value of the atmospheric pressure sensor. An abnormality may occur in the measured value of the atmospheric pressure sensor that is a reference for voltage value control. In such a case, the voltage value may be controlled based on an erroneous measurement value, and there is room for improvement from the viewpoint of ensuring insulation performance.

  Here, the cause of the abnormality in the measured value of the atmospheric pressure sensor is the failure of the atmospheric pressure sensor, etc. Even if there is no failure in the atmospheric pressure sensor, the ventilation filter attached to the waterproof case that stores it If there is an abnormality in the measured value, an abnormality may occur in the measured value. As described in Patent Document 2, since atmospheric pressure outside the case is introduced to the atmospheric pressure sensor via a water-repellent ventilation filter, for example, water adheres to the ventilation filter and the ventilation performance decreases. In such a case, an abnormal value may be detected. In addition, it is extremely rare that water adheres to the ventilation filter.For example, when the engine room is subjected to high-pressure washing in a state where clay or the like adheres to the ventilation filter due to long-term use and the water repellency is lowered. May happen.

  When the cause of abnormality detection of the atmospheric pressure sensor is due to water adhesion of the ventilation filter, if the ventilation filter dries, the ventilation performance is restored and normal atmospheric pressure can be measured. Therefore, if it is determined that the measured value of the atmospheric pressure sensor is abnormal and the cause is found to be a temporary abnormality caused by the ventilation filter, a higher level of boosting can be achieved from the viewpoint of ensuring insulation performance. Control becomes possible.

  However, in the conventional control device, it is determined whether the cause of the abnormality detection of the atmospheric pressure sensor is caused by a failure of the atmospheric pressure sensor or the temporary abnormality caused by water adhesion of the ventilation filter. I can't. Furthermore, there is a possibility that boost control is performed based on an erroneous measurement value.

  An object of the present invention is to provide a boost converter control device for an electric vehicle that can identify abnormality detection of an atmospheric pressure sensor and identify the cause of the abnormality detection.

  A boost converter control device for an electric vehicle according to the present invention includes a boost converter that boosts a power supply voltage and supplies the boosted voltage to an electric motor, an atmospheric pressure sensor stored in a waterproof case with a ventilation filter, and an atmospheric pressure sensor. In a boost converter control device for an electric vehicle including a boost control device that controls boosting by a boost converter based on a measured value, the measured value of an atmospheric pressure sensor and the atmospheric pressure measurement can be performed outside the waterproof case Comparing with the atmospheric pressure measurement value of the sensor, if the difference between each measurement value exceeds the predetermined value, the abnormality determination means to determine that the measurement value of the atmospheric pressure sensor is abnormal, and the abnormality of the measurement value is determined After a predetermined waiting time has elapsed since then, it is determined again whether or not the measured value of the atmospheric pressure sensor is normal, and it is determined whether or not the measured value is abnormal due to the ventilation filter. And having a factor determining means.

  Moreover, it is preferable to have a standby time calculation means for calculating the standby time based on a predetermined parameter.

  In addition, it is preferable that the standby time calculation means calculates again the standby time based on the changed parameter value when the parameter value used for calculating the standby time has changed beyond a predetermined range.

  In addition, when it is determined that the measured value of the atmospheric pressure sensor is abnormal, it is preferable to cause the boosting control device to release the limitation of the boosting by the boosting converter based on the measured value of the atmospheric pressure sensor.

  According to the step-up converter control device for an electric vehicle according to the present invention, the measurement value of the atmospheric pressure sensor is compared with the atmospheric pressure measurement value of a sensor installed outside the waterproof case and capable of measuring atmospheric pressure. When the difference between the values exceeds a predetermined value, there is an abnormality determination means that determines that the measured value of the atmospheric pressure sensor is abnormal. It is possible to reliably prevent the boost control based on the measured value.

  In addition, after a predetermined waiting time has elapsed since the measurement value abnormality was determined, it is determined again whether the measurement value of the atmospheric pressure sensor is abnormal, and the abnormality in the measurement value is caused by the ventilation filter. Since there is a factor determination means for determining whether or not the atmospheric pressure sensor, an abnormality in the measured value of the atmospheric pressure sensor is caused by a failure of the atmospheric pressure sensor or a temporary abnormality such as water adhesion of the ventilation filter It is possible to determine whether it is a thing. Accordingly, unnecessary boost restriction can be avoided while ensuring insulation performance, and higher level boost control can be achieved.

  In the invention according to claim 2, since the standby time calculation means for calculating the standby time based on a predetermined parameter is provided, for example, when water adheres to the ventilation filter, the temperature and humidity around the waterproof case, the electric vehicle It is possible to calculate a drying time of water adhering to the ventilation filter based on the altitude at which the vehicle is traveling, that is, a standby time that is necessary and sufficient to determine the cause of abnormality detection. Therefore, it becomes easy to prevent quick recovery from the standby state or erroneous factor determination due to insufficient standby time.

  In the invention according to claim 3, when the value of the parameter used for calculating the waiting time changes beyond a predetermined range, the waiting time is calculated again based on the changed parameter value. When the temperature and altitude change during traveling, the drying time of water attached to the ventilation filter can be accurately calculated. On the other hand, execution of recalculation due to slight changes in parameters can be suppressed, and delays in recovery from the standby state can be prevented.

  In the invention according to claim 4, when it is determined that the measured value of the atmospheric pressure sensor is abnormal, the boost control device is made to release the restriction of the boost by the boost converter based on the measured value of the atmospheric pressure sensor. It is possible to prevent the boost restriction based on the erroneous measurement value of the atmospheric pressure sensor, and to avoid the unnecessary motor output limit caused by the unnecessary boost restriction.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a boost converter control device for an electric vehicle. FIG. 2 is a schematic diagram showing a waterproof case in which an atmospheric pressure sensor is stored and a ventilation filter is installed in a through hole.

  An electric vehicle boost converter control device 10 (hereinafter referred to as boost converter control device 10) is a device including a boost control device that limits boosting by the boost converter 12 based on a measured value of the atmospheric pressure sensor 11. Further, the boost converter control device 10 includes an abnormality detection determination device 18 to be described later. Here, the electric vehicle means a vehicle driven by an electric motor (indicated by M in FIG. 1) such as an electric vehicle, a fuel cell vehicle, and a hybrid vehicle. Hereinafter, the electric vehicle will be mainly described as a hybrid vehicle, but the present invention is not limited to this.

  The boost converter 12 is a device (circuit) having a function of boosting the power supply voltage and supplying it to the motor as described above. Specifically, the input voltage to the inverter 13 for the motor can be boosted in accordance with the operating status of the motor or the like, for example, the power supply voltage of about 240V can be boosted to a maximum of 650V. When the electric vehicle includes a generator, it also has a function of stepping down the voltage supplied from the generator. The inverter 13 mainly has a function of converting a direct current from the power source into an alternating current and supplying the alternating current to the electric motor.

  Generally, the boost converter 12 and the inverter 13 are controlled by a motor generator electronic control unit (MG-ECU), and a unit composed of these three devices is called a power control unit (PCU). The MG-ECU controls the boost converter 12 and the like in accordance with signals from a hybrid electronic control unit (HV-ECU) that comprehensively controls the hybrid vehicle system. Since the HV-ECU comprehensively controls the output of the electric motor and the engine in accordance with signals from various sensors and ECUs such as the engine and the driver's output request, the boosted voltage by the boost converter 12 is basically Is determined according to the driver's output request.

  The atmospheric pressure sensor 11 is a sensor that measures atmospheric pressure, which is a parameter for boost control. Since the sensor element portion does not function when wet, as shown in FIG. 2, the atmospheric pressure sensor 11 is stored in a waterproof case 14 and installed in an engine room (not shown). Here, the atmospheric pressure sensor 11 is not particularly limited, and a known sensor mounted on a conventional control device or the like can be used.

  The waterproof case 14 that houses the atmospheric pressure sensor 11 is provided with a through hole 15, and a ventilation filter 16 is attached to the through hole 15. Here, the through hole 15 is, for example, a hole that is provided on the case surface of the waterproof case 14 and communicates the outside of the waterproof case 14 and the inside in which the atmospheric pressure sensor 11 is stored. Therefore, atmospheric pressure outside the case is introduced into the atmospheric pressure sensor 11 via the ventilation filter 16. The installation location of the atmospheric pressure sensor 11 is not particularly limited, but is preferably stored in a waterproof case 14 together with the PCU as shown in FIG.

  The ventilation filter 16 attached to the waterproof case 14 is a porous film having a function of capturing water and dust and allowing only air to pass through. As the ventilation filter 16, those made of various materials and structures, for example, a polymer porous membrane and a ceramic porous membrane can be used. Polymer porous membranes and ceramic porous membranes include membranes produced by various production methods (phase separation method, extraction method, chemical treatment method, foaming method, fiberizing method, sintering method, etc.) and various resins. (Acrylic resin, olefin resin, silicone resin, fluororesin, polyimide resin, cellulose resin, etc.) and a film composed of various ceramics (titanium oxide, silica, etc.) can be used. From the viewpoint of water repellency and durability, it is preferable to use a polymer porous membrane, and among these, a ventilation filter composed of a fluororesin such as polytetrafluoroethylene (PTFE) that is particularly excellent in water repellency and durability. It is particularly preferred to use Moreover, in order to raise mechanical strength, the filter which affixed the nonwoven fabric etc. to the polymeric porous membrane can be used.

  The boost converter control device 10 is provided with a boost control device that controls boosting by the boost converter 12 based on the measured value of the atmospheric pressure sensor 11 as described above. When the electric vehicle travels on a high altitude with a low atmospheric pressure, the boost control device sets an upper limit value of the boost voltage and restricts the boost by the boost converter 12, thereby preventing insulation breakdown of the motor or the like. it can. The upper limit value of the boost voltage to be set can be arbitrarily determined according to the structure of the electric motor or the like, and is stored in advance in the HV-ECU or MG-ECU as in the conventional control device.

  Since the boost control device is a device that controls the operation of boost converter 12, it is preferably configured as a part of the PCU, and is generally configured as a part of MG-ECU. Hereinafter, the boost control device will be described as the boost converter control unit 17 that is a part of the MG-ECU.

  As shown in FIG. 1, the boost converter control device 10 includes an abnormality detection determination device 18. The abnormality detection determination device 18 includes an abnormality determination unit 19, a standby time calculation unit 20, and a factor determination unit 21. The abnormality detection determination device 18 has a function of identifying abnormality detection of the atmospheric pressure sensor 11 and specifying the cause of the abnormality detection. The function is executed by the functions of the abnormality determination unit 19 and the factor determination unit 21, and is further expanded by the function of the standby time calculation unit 20.

  Abnormality detection determination device 18 has the above-described functions, and is configured as a part of PCU, MG-ECU or HV-ECU in order to control the operation of boost converter 12 as will be described later. More preferably, as shown in FIG. 1, it is configured as a part of the HV-ECU. Hereinafter, the abnormality detection determination device 18 will be described as a part of the HV-ECU.

  The abnormality determination unit 19 has a function of determining whether or not the measured value of the atmospheric pressure sensor 11 is normal. Specifically, by comparing the measured value of the atmospheric pressure sensor 11 with the measured atmospheric pressure value of a sensor installed outside the waterproof case 14 and capable of measuring atmospheric pressure, the difference between the measured values becomes a predetermined value. When it exceeds, the measured value of the atmospheric pressure sensor 11 is determined to be abnormal. The function of the abnormality determination unit 19 can prevent pressure increase control based on an abnormal measurement value, and can further determine the cause of abnormality detection of the atmospheric pressure sensor 11 by the function of the factor determination unit 21 described later. It becomes possible.

  It is preferable that an appropriate value is set as a predetermined value (hereinafter also referred to as a threshold value) serving as an abnormality detection index from the viewpoint of ensuring insulation performance. In addition, as shown in FIG. 3 and the like, there may be a slight difference in the value of each atmospheric pressure sensor even during normal operation before water adheres to the ventilation filter 16, so the difference in the measured value in the initial stage is also taken into consideration. Thus, the predetermined value is determined. The predetermined value is shown in FIGS. 3 to 5 as a threshold value, and can be appropriately changed according to the sensor to be used, the vehicle type, and the like.

  Here, the determination that the measured value of the atmospheric pressure sensor 11 is abnormal is not only when the measured value of the atmospheric pressure sensor 11 is abnormal, but also the measured value of the sensor 22 outside the waterproof case 14 is abnormal. Of course, some cases are included. Even if there is an abnormality in any of the sensors, the measured value of the atmospheric pressure sensor 11 is processed as an abnormality for convenience. In order to further improve the accuracy of abnormality determination, a plurality of sensors can also be used as comparison sensors for abnormality determination.

  The sensor installed outside the waterproof case 14 and capable of measuring atmospheric pressure is not particularly limited as long as it is a sensor installed outside the waterproof case 14. For example, an intake pressure sensor mounted on an intake manifold (not shown). 22 (hereinafter referred to as intake pressure sensor 22) or a dedicated atmospheric pressure sensor can be used. From the viewpoint of cost reduction and the like, it is preferable to use an intake pressure sensor 22 which is an existing sensor as shown in FIG. When the intake pressure sensor 22 is used as an abnormality determination comparison sensor, it is necessary to use a value measured when the engine (not shown) is stopped.

  The factor determination unit 21 has a function of determining whether an abnormality in the measured value of the atmospheric pressure sensor 11 is an abnormality caused by the ventilation filter 16. Specifically, after a predetermined waiting time has elapsed since the abnormality determination unit 19 determined abnormality detection, the factor determination is performed by determining again whether or not the measured value of the atmospheric pressure sensor 11 is still abnormal. Made. By the function of the factor determination unit 21, it is determined whether the abnormality in the measured value of the atmospheric pressure sensor 11 is caused by a failure of the atmospheric pressure sensor 11 or the like or a temporary abnormality of the ventilation filter 16. It becomes possible. The predetermined waiting time may be a fixed time such as 1 to 10 hours. Examples of the abnormality caused by the ventilation filter 16 include an abnormality caused by water adhering to the ventilation filter 16 and lowering the ventilation performance. In this case, the predetermined waiting time is 0.5 to 5. It is preferably time, and more preferably 1 to 3 hours. Hereinafter, the abnormality caused by the ventilation filter 16 will be described as being caused by water adhering to the ventilation filter 16 and deterioration of ventilation performance.

The standby time calculation unit 20 has a function of calculating the standby time based on a predetermined parameter.
Furthermore, when the value of the parameter used for calculating the standby time changes beyond a predetermined range, the standby time based on the changed parameter value is calculated again. The function of the standby time calculation unit 20 causes the temperature and humidity around the waterproof case 14 and the electric vehicle to run when there is an abnormality caused by water adhering to the ventilation filter 16 and reducing the ventilation performance. It is possible to calculate the waiting time necessary and sufficient for determining the drying time of the water adhering to the ventilation filter 16, that is, the factor of abnormality detection, based on the altitude and the like. Therefore, it becomes easy to prevent quick recovery from the standby state or erroneous factor determination due to insufficient standby time.

  Examples of the predetermined parameter used for calculating the standby time include the temperature and humidity around the waterproof case 14 and the altitude at which the electric vehicle is traveling. Both parameters affect the evaporation rate of water adhering to the ventilation filter 16. The calculation of the standby time by the standby time calculation unit 20 can be performed, for example, by increasing or decreasing the reference time using these parameters with reference to a time determined based on past examination data or experiments. Specifically, when the parameter value is more advantageous for drying water than the precondition for the reference time, for example, when the temperature is higher than the reference time condition, the time shorter than the reference time is set. Will be calculated. On the other hand, when the humidity is higher than the reference time condition, a time longer than the reference time is calculated.

  As a sensor or measuring instrument for measuring these parameters, a known sensor or the like can be used, and a dedicated machine used only for calculating the standby time can be provided. In the case where a dedicated machine is provided, it is preferably provided around the waterproof case 14 in order to calculate a more accurate standby time. On the other hand, from the viewpoint of cost reduction or the like, the above parameters can be measured using an existing sensor or the like. For example, an engine intake air temperature sensor or the like can be used for the air temperature, and a rainy weather sensor used for a wiper or the like can be used for the humidity. As the altitude, an altitude such as navigation can be used.

  The operation of boost converter control device 10 having the above configuration, particularly the function of abnormality detection determination device 18, will be described in detail with reference to FIGS. FIG. 3 is a diagram showing the passage of time of the measured value of the atmospheric pressure sensor, and shows a state from the state where water has adhered to the ventilation filter to cause poor ventilation to the time of drying through a waiting time. FIG. 4 is a diagram showing a case where a failure of the atmospheric pressure sensor occurs in FIG. 3, and FIG. 5 is a diagram showing a case where the parameters used for calculating the elapsed time in FIG. 3 change. FIG. 6 is a flowchart showing a processing procedure of boost converter control device 10. The following processing procedure will be described with reference to FIG.

  First, the atmospheric pressure values of the atmospheric pressure sensor 11 and the intake pressure sensor 22 are compared, and it is determined whether or not the difference between the atmospheric pressure values exceeds a threshold value (S10). The state where the boost converter control unit 17 performs control to limit the boost by the boost converter 12 based on the measured value of the atmospheric pressure sensor 11 is a normal boost control mode, which is START in FIG. This determination can be performed at a predetermined interval that is arbitrarily determined, but the atmospheric pressure measurement by the intake pressure sensor 22 is performed when the engine of the hybrid vehicle is stopped. If the difference between the measured values of the sensors is within the threshold value range, the measured value of the atmospheric pressure sensor 11 is normal, the normal boost control mode is maintained, and S10 is repeated at the predetermined interval.

  As shown in FIG. 3, when it is determined in S10 that the difference between the measured values of the sensors exceeds the threshold value, the measured value of the atmospheric pressure sensor 11 is determined to be abnormal (S11). Here, as described above, it is not known which measured value of the atmospheric pressure sensor 11 or the intake pressure sensor 22 is abnormal, but it is determined that the measured value of the atmospheric pressure sensor 11 is abnormal for convenience. As described above, since the abnormality detection of the atmospheric pressure sensor 11 can be identified and determined, for example, the following processing is executed to reliably prevent the pressure increase limitation based on the erroneous measurement value of the atmospheric pressure sensor 11. Is possible. 3 to 5 show the case where the measured value of the intake pressure sensor 22 rises and exceeds the threshold value, that is, the case where the electric vehicle shifts from highland travel to lowland travel. The abnormality detection can be determined in the same manner when the vehicle shifts from high to low.

  If it is determined in S11 that an abnormality has been detected, the pressure increase control based on the atmospheric pressure value is canceled (S12). More specifically, the abnormality determination unit 19, that is, the HV-ECU gives a control command for canceling the boost restriction to the boost converter control unit 17, and the boost restriction based on the measured value of the atmospheric pressure sensor 11 is released. The Accordingly, it is possible to prevent a boost restriction based on an erroneous measurement value of the atmospheric pressure sensor 11 and to avoid an unnecessary motor output limit caused by an unnecessary boost restriction. In some cases, a control command for setting an upper limit value of the boost voltage can be given to boost converter control unit 17. The procedure of S10 to S12 is executed by the function of the abnormality determination unit 19 of the abnormality detection determination device 18.

  Next, a standby time is calculated based on a predetermined parameter (S13). As shown in FIGS. 3 and 5, the calculation of the waiting time is executed without being limited to the case where water actually adheres to the ventilation filter 16. As the predetermined parameters, the temperature and humidity around the waterproof case 14 and the altitude at which the electric vehicle is traveling are used. Based on this, it is assumed that water has adhered to the ventilation filter 16 and that water has adhered. In some cases, the time until the water dries is calculated. Therefore, it is possible to calculate a standby time that is necessary and sufficient to determine a factor for detecting an abnormality, and it is easy to prevent an erroneous factor determination due to quick recovery from a standby state or lack of standby time. This procedure is executed by the function of the elapsed time calculation unit 20 of the abnormality detection determination device 18.

  Until the calculated standby time elapses, the standby state is maintained without limiting the pressure increase (S14). Since the waiting time is a necessary and sufficient condition for the water attached to the ventilation filter 16 to dry as described above, the water attached to the ventilation filter 16 is dried by this waiting. In addition, when the parameter used for calculation of the standby time changes beyond a predetermined range, the standby time (not shown) is recalculated. For example, when the temperature or the altitude at which the electric vehicle is traveling has changed beyond a predetermined range, the drying time of the water attached to the ventilation filter 16 changes. Can be set. On the other hand, by providing the predetermined range, it is possible to prevent recalculation due to a slight change in parameters, and to prevent a delay in recovery from the standby state. Therefore, the predetermined range is preferably determined in consideration of accurate calculation of the standby time and prevention of delay in recovery from the standby state.

  In addition, when water adheres to the ventilation filter 16 and the measured value of the atmospheric pressure sensor 11 is determined to be abnormal in S10, the difference between the measured values of the sensors temporarily falls below a threshold value. In S14, the control setting can be made such that the redetermination described later is not performed. As shown in FIG. 5, in the state where the difference between the measured values of the sensors is temporarily less than or equal to the threshold value, if the determination is performed again and it is determined that the atmospheric pressure sensor 11 is normal, each sensor is again detected. When the difference between the measured values is equal to or greater than the threshold value, the standby time is counted from that point, so that recovery from the standby state is delayed. By setting as described above, quick recovery from the standby state can be achieved.

  After the standby time has elapsed, the abnormality of the measured value of the atmospheric pressure sensor is determined again (S15). This re-determination is performed by comparing the atmospheric pressure measurement values of the respective sensors in the same manner as in S10. As described later, an abnormality in the measurement value of the atmospheric pressure sensor 11 is caused by a failure of the atmospheric pressure sensor 11 or the like. It is possible to determine whether it is caused by a temporary abnormality such as water adhering to the ventilation filter 16.

  As shown in FIG. 4, when the measured value of each sensor still exceeds the threshold value even after the standby time has elapsed, it is determined that the abnormality is not detected due to water adhesion on the ventilation filter 16 (S16). The upper limit value of the boosted voltage, for example, 500 V is set (S17). In this case, it is not possible to determine specific factors such as whether the atmospheric pressure sensor 11 is malfunctioning, the intake pressure sensor 22 is malfunctioning, or the wiring connected to the sensor is malfunctioning. However, since it can be determined that this is not a temporary abnormality, it is preferable to perform a boost restriction and maintenance of the electric vehicle is required.

  On the other hand, as shown in FIGS. 3 and 5, if the difference between the measured values of the sensors is within the threshold range after the standby time has elapsed, the measured value of the atmospheric pressure sensor 11 is normal and the water of the ventilation filter 16 is It is determined that an abnormality has occurred due to adhesion (S18), and the normal boost control mode is restored (S19). In this case, it is possible to clearly identify the temporary abnormality detection caused by the ventilation filter 16. The procedure of S14 to S19 is executed by the function of the elapsed time calculation unit 20 of the abnormality detection determination device 18.

  As described above, according to the boost converter control device 10, the abnormality determination unit 19 can identify abnormality detection of the atmospheric pressure sensor 11, and reliably prevents voltage value control based on an erroneous measurement value of the atmospheric pressure sensor 11. can do. Furthermore, since the factor determination unit 21 determines again whether or not the measurement value of the atmospheric pressure sensor 11 is abnormal after a predetermined standby time has elapsed since the measurement value abnormality was determined, the measurement value abnormality Can be specified as a temporary abnormality due to water adhesion of the ventilation filter 16. Accordingly, unnecessary boost restriction can be avoided while ensuring insulation performance, and higher level boost control can be achieved.

  As described above, water adheres to the ventilation filter 16, for example, when the engine room is subjected to high-pressure washing in a state where clay or the like adheres to the ventilation filter 16 due to long-term use and water repellency is lowered. It is extremely rare to happen. It is not preferable that the upper limit value of the boost voltage is set and an unnecessary boost limit is executed only by detecting such a temporary abnormality caused by the ventilation filter 16. According to step-up converter control device 10, as described above, unnecessary step-up restriction can be avoided, and unnecessary output restriction of the electric motor can be prevented.

  Further, the boost converter control device 10 has a standby time calculation unit 20 that calculates the standby time based on a predetermined parameter. Therefore, when water adheres to the ventilation filter 16, it is based on parameters such as ambient temperature, altitude, and humidity. Thus, the drying time of the water adhering to the ventilation filter 16, that is, the necessary and sufficient waiting time can be calculated. Therefore, it becomes easy to prevent the atmospheric pressure sensor 11 from being promptly restored from the standby state or erroneous factor determination.

  In the above description, when the electric vehicle travels at a high altitude with a low atmospheric pressure, the upper limit value of the boost voltage is set and the boost by the boost converter 12 is limited. However, as the boost control, It is also possible to set the target boost voltage to be variable at any time according to the atmospheric pressure value.

It is a block diagram which shows the structure of the boost converter control apparatus of an electric vehicle. It is a schematic diagram which shows the waterproof case in which the atmospheric pressure sensor was stored and the ventilation filter was installed in the through-hole. It is a figure which shows the time passage of the measured value of an atmospheric pressure sensor, and has shown the state until it dries through a waiting time from the state which water adhered to the ventilation filter and it became poor ventilation. It is a figure which shows the case where a failure of an atmospheric pressure sensor has occurred in FIG. FIG. 4 is a diagram showing a control setting in which re-determination is not performed within a standby time when a difference between measured values of sensors in FIG. 3 temporarily falls within a threshold range. It is a flowchart which shows the process sequence of a boost converter control apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Boost converter control apparatus of electric vehicle, 11 Atmospheric pressure sensor, 12 Boost converter, 13 Inverter, 14 Waterproof case, 15 Through-hole, 16 Ventilation filter, 17 Boost converter control part, 18 Abnormality detection determination apparatus, 19 Abnormality determination part, 20 standby time calculation unit, 21 factor determination unit, 22 intake pressure sensor mounted on intake manifold.

Claims (4)

A boost converter that boosts the power supply voltage and supplies it to the motor, an atmospheric pressure sensor stored in a waterproof case fitted with a ventilation filter, and a booster that controls the boost by the boost converter based on the measured value of the atmospheric pressure sensor A boost converter control device for an electric vehicle comprising:
When the measured value of the atmospheric pressure sensor is compared with the measured atmospheric pressure value of a sensor installed outside the waterproof case and capable of measuring atmospheric pressure, and the difference between the measured values exceeds the specified value, the atmospheric pressure sensor An abnormality determining means for determining that the measured value is abnormal,
After a predetermined waiting time has elapsed since the measurement value abnormality is determined, it is determined again whether the measurement value of the atmospheric pressure sensor is abnormal, and the measurement value abnormality is an abnormality caused by the ventilation filter. Factor determining means for determining whether or not,
A boost converter control device for an electric vehicle, comprising: The step-up converter control device for an electric vehicle according to claim 1,
A boost converter control device for an electric vehicle, comprising standby time calculation means for calculating the standby time based on a predetermined parameter. In the boost converter control device for an electric vehicle according to claim 2,
The waiting time calculating means calculates again the waiting time based on the changed parameter value when the value of the parameter used for calculating the waiting time changes beyond a predetermined range. Boost converter control device. In the boost converter control device for an electric vehicle according to any one of claims 1 to 3,
When it is determined that the measured value of the atmospheric pressure sensor is abnormal, the boosted converter control device for the electric vehicle is configured to cause the boosting control device to release the limitation of the boosting by the boosting converter based on the measured value of the atmospheric pressure sensor. .

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