JP2010139245A - Device for detecting abnormality - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for detecting abnormality which can accurately detect the abnormality of electric circuit and which is high in reliability. <P>SOLUTION: The resistance values of the resistive elements of an INV voltage sensor 21, constituted as a voltage division circuit, are set so that an input voltage conversion value determined from an output signal of the INV voltage sensor 21, at failure of the resistance element having the smallest resistance value among the resistive elements of the INV voltage sensor 21, does not overlap, inclusive of error range, with the input voltage conversion value being determined from the output signal of a B/C voltage sensor 22, which monitors the same battery voltage VBAT as for the INV voltage sensor 21. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an abnormality detection device that detects an abnormality of an electric circuit.

Conventionally, as an abnormality detection device for detecting an abnormality in an electric circuit, for example, a device described in Patent Document 1 is known. The abnormality detection device described in Patent Document 1 is an abnormality detection device that is applied to a power supply circuit having two output voltages. In normal operation, the two output voltages are divided by voltage dividing resistors, respectively. When the later potential becomes equal and one of the two output voltages changes from the set value, current flows to the light emitting element of the photocoupler through the diode due to the potential difference after voltage division, the photocoupler is activated, and an abnormality is detected It has a configuration.
JP-A-4-168916

  However, in the conventional abnormality detection device described in Patent Document 1, for example, even when the power supply circuit operates normally and the two output voltages are set values, after voltage division due to an error in voltage division, etc. When a slight potential difference occurs in the potential, the photocoupler operates and it is determined that there is an abnormality. For example, there is a problem that the abnormality detection accuracy is insufficient and the reliability is insufficient.

  The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a highly reliable abnormality detection apparatus capable of detecting an abnormality of an electric circuit with high accuracy.

  An abnormality detection apparatus according to the present invention determines abnormality by comparing a plurality of circuits that generate output signals based on the same input voltage and an input voltage conversion value obtained by converting the output signals of the plurality of circuits into input voltages. And at least one of the plurality of circuits is a voltage dividing circuit that divides an input voltage by a voltage dividing resistor including a plurality of resistance elements connected in series to generate an output signal. The input voltage conversion value obtained from the output signal of the voltage dividing circuit when the resistance element having the smallest resistance value among the plurality of resistance elements has a failure relative to the input voltage conversion value obtained from the output signal of the other circuit. Therefore, the resistance value of the resistance element of the voltage dividing circuit is set so as not to overlap including the error range.

  The abnormality detection device according to the present invention includes a voltage dividing circuit that divides an input voltage by a voltage dividing resistor including a plurality of resistance elements connected in series to generate an output signal, and outputs the output signal of the voltage dividing circuit to the input voltage. Input means obtained from the output signal when the resistance element having the smallest resistance value out of the plurality of resistance elements of the voltage dividing circuit is provided. The resistance value of the resistance element of the voltage dividing circuit is set so that the converted value does not overlap with the predetermined reference value including the error range.

  According to the abnormality detection device of the present invention, when an abnormality occurs in the voltage dividing circuit, the input voltage conversion value of the voltage dividing circuit is necessarily different from the input voltage conversion value of the other circuit or a predetermined reference value. By comparing these values, the abnormality of the voltage dividing circuit can be detected with high accuracy. Even if the cause of the abnormality in the voltage divider circuit is the failure of the resistor element having the smallest resistance value, the input voltage conversion value of the voltage divider circuit is always the input voltage conversion value of another circuit or a predetermined reference value. Since the values are different, even when the voltage dividing circuit is abnormal due to a failure of another resistance element, the abnormality can be reliably detected.

  Hereinafter, as the best mode for carrying out the present invention, an application example in an application for detecting an abnormality of a voltage sensor (high voltage monitor circuit) for monitoring a battery voltage of a high voltage battery mounted on a hybrid vehicle will be exemplified. Specific embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a system configuration diagram illustrating an example of a drive system for a hybrid vehicle. In the hybrid vehicle drive system shown in FIG. 1, a motor generator (MG) 1 is connected to an engine 3 via a clutch 2 and has a function of starting the engine 3. The motor generator 1 is connected to the transmission 5 via the clutch 4 and generates a driving force for driving the hybrid vehicle. Note that the total driving force of the hybrid vehicle is a combined driving force of the engine 3 and the motor generator 1 or each driving force.

  The vehicle controller 6 inputs information such as the vehicle speed, shift position, accelerator operation amount, and brake operation amount of the hybrid vehicle, performs drive force control and energy management in accordance with these information, and performs the engine 3, clutches 2, 4 Then, a torque command, an operation state command and the like are output to the motor controller (M / C) 7 and the like. In FIG. 1, the control circuit of the engine 3 and the clutches 2 and 4 is shown as being integrated with each device.

  The motor controller 7 controls the operation of the inverter (INV) 8 based on the torque command from the vehicle controller 6.

  The inverter 8 supplies electric power necessary for starting the engine 3 and driving the hybrid vehicle to the motor generator 1 in accordance with a command from the motor controller 7. The inverter 8 includes a voltage sensor that monitors the battery voltage of the high-voltage battery 9, and outputs an output signal of the voltage sensor to the motor controller 7.

  The high voltage battery 9 supplies necessary power to the inverter 8 under the control of the battery controller 10.

  The battery controller (B / C) 10 includes a voltage sensor that monitors the battery voltage of the high-voltage battery 9 and a current sensor that monitors the battery current, and the state of the high-voltage battery 9 is monitored by monitoring the battery voltage and current. And charge / discharge control and protection control of the high-voltage battery 9 are performed.

  Each control device in this drive system, that is, the vehicle controller 6, the motor controller 7, the battery controller 10, and the like are connected so as to be communicable by a communication means such as a CAN (Controller Area Network), for example. Various signals can be exchanged.

  FIG. 2 is a block diagram of a control system related to the motor generator 1. As shown in FIG. 2, the motor controller 7 has a magnetic pole position detection unit 11, a three-phase / two-phase conversion unit 12, a current command unit 13, a current control unit 14, and a two-phase control function. A / 3 phase converter 15 is provided.

  The magnetic pole position detector 11 inputs a signal from the magnetic pole position sensor 16 attached to the motor generator 1 and converts it into a magnetic pole position θ and an electrical angular frequency ω. The magnetic pole position θ is supplied to the three-phase / two-phase converter 12 and the two-phase / three-phase converter 15, and the electrical angular frequency ω is supplied to the current command unit 13.

  The three-phase / 2-phase converter 12 converts the three-phase AC actual currents iu, iv, iw obtained by the current sensor 17 into the two-phase AC actual currents id, iq based on the magnetic pole position θ. The two-phase AC actual currents id and iq are supplied to the current control unit 14.

  The current command unit 13 generates a d and q-axis current command value id * to the motor generator 1 based on the torque command T * from the vehicle controller 6, the electrical angular frequency ω, and the output signal of the voltage sensor 21 of the inverter 8. , Iq * is set using a current table.

  The current control unit 14 has zero deviation between the d and q axis current command values id * and iq * set by the current command unit 13 and the two-phase AC actual currents id and iq from the three-phase / two-phase conversion unit 12. Thus, the voltage command values vd * and vq * for the d and q axes are determined.

  The two-phase / three-phase converter 15 converts the voltage command values vd * and vq * determined by the current controller 14 into three-phase AC voltage command values Vu *, Vv *, and Vw * based on the magnetic pole position θ. To do.

  The three-phase AC voltage command values Vu *, Vv *, Vw * generated by the two-phase / three-phase converter 15 of the motor controller 7 are supplied to the inverter 8. In the inverter 8, the switching of a power element such as an IGBT is controlled according to the three-phase AC voltage command values Vu *, Vv *, Vw * from the motor controller 7. It is converted into a phase AC voltage and supplied to the motor generator 1.

  The inverter 8 is provided with a voltage sensor (hereinafter referred to as an INV voltage sensor) 21 for monitoring the battery voltage of the high voltage battery 9 as described above, and the output signal of the INV voltage sensor 21 is a motor controller. 7 current command unit 13. The battery voltage of the high voltage battery 9 is also monitored by a voltage sensor (hereinafter referred to as a B / C voltage sensor) 22 provided in the battery controller 10. Therefore, by comparing the battery voltage monitored by the INV voltage sensor 21 with the battery voltage monitored by the B / C voltage sensor 22, it is possible to determine whether or not an abnormality has occurred in the INV voltage sensor 21.

  That is, since the INV voltage sensor 21 and the B / C voltage sensor 22 monitor the same battery voltage, the output of the INV voltage sensor 21 is considered when ignoring errors due to sensor detection errors and voltage drops in the harness. The battery voltage obtained from the signal (the input voltage converted value obtained by converting the output signal of the INV voltage sensor 21 into the battery voltage) and the battery voltage obtained from the output signal of the B / C voltage sensor 22 (the output of the B / C voltage sensor 22) The input voltage conversion value obtained by converting the signal into the battery voltage should match. In other words, if a significant difference is found between the input voltage conversion value obtained from the output signal of the INV voltage sensor 21 and the input voltage conversion value obtained from the output signal of the B / C voltage sensor 22, these INV voltage sensors It can be determined that an abnormality has occurred in either the B 21 or the B / C voltage sensor 22.

  However, when an abnormality occurs in either the INV voltage sensor 21 or the B / C voltage sensor 22, the input voltage conversion value obtained from the output signal of the voltage sensor in which the abnormality has occurred and the output signal of the normal voltage sensor If there is a case where the difference from the calculated input voltage converted value falls within an allowable error range, the abnormality of the INV voltage sensor 21 or the B / C voltage sensor 22 is correctly determined by comparing these values. Can not do it. Therefore, in order to accurately determine these abnormalities using the output signals of the INV voltage sensor 21 and the B / C voltage sensor 22, an input voltage conversion value obtained from the output signal of the voltage sensor in which the abnormality has occurred and a normal voltage are obtained. It is required that the input voltage converted value obtained from the output signal of the sensor is always different even when the error range is taken into consideration. Hereinafter, an example of a technical solution for satisfying such a requirement will be described with specific examples.

  FIG. 3 is an example of a simplified circuit diagram in which the INV voltage sensor 21 and the B / C voltage sensor 22 shown in FIGS. 1 and 2 and their peripheral portions are extracted. In the example shown in FIG. 3, the INV voltage sensor 21 divides the battery voltage VBAT of the high-voltage battery 9 by a voltage dividing resistor composed of a number of resistor elements R1 to Rn, r connected in series, thereby obtaining the battery voltage VBAT. The voltage dividing circuit is configured to generate a proportional voltage VA as an output signal, and the generated output signal (voltage VA) is output to the motor controller 7. Here, a large number of resistance elements R1 to Rn, r are connected in series to form a voltage dividing resistor because the circuit power supply voltage of the INV voltage sensor 21 is several volts to several tens of volts or less, whereas the battery voltage VBAT. Is very high at several hundred volts, and it is necessary to reduce the voltage corresponding to the battery voltage VBAT to the circuit power supply voltage. On the other hand, the battery voltage VBAT greatly exceeds the rated voltage of a general resistance element. This is because it is necessary to reduce the voltage applied to each resistance element by connecting the resistance elements R1 to Rn, r in series.

  In the example of FIG. 3, the motor controller 7 and the battery controller 10 are communicably connected via the CAN line, and the output signal of the B / C voltage sensor 22 is A / D converted and transmitted via the CAN line. 10 to the motor controller 7. Then, the motor controller 7 uses the output signal of the INV voltage sensor 21 and the output signal of the B / C voltage sensor 22 transmitted from the battery controller 10 via the CAN line to form an INV voltage configured as a voltage dividing circuit. It is determined whether an abnormality has occurred in the sensor 21. The motor controller 7 may A / D convert the output signal of the INV voltage sensor 21 and send it to the battery controller 10 via the CAN line. In this case, the battery controller 10 is connected to the B / C voltage sensor. 22 is used, and the output signal of the INV voltage sensor 21 transmitted from the motor controller 7 via the CAN line is used to determine whether or not an abnormality has occurred in the INV voltage sensor 21 configured as a voltage dividing circuit. To do. Also, both the output signal of the INV voltage sensor 21 and the output signal of the B / C voltage sensor 22 are transmitted to other control devices other than the motor controller 7 and the battery controller 10 via the CAN line, and abnormalities are detected in the other control devices. You may make it perform determination.

  Here, the INV voltage sensor 21 configured as a voltage dividing circuit uses the output signal of the INV voltage sensor 21 and the output signal of the B / C voltage sensor 22 to control the motor controller 7 (or the battery controller 10 or other control). In order to reliably determine whether or not the INV voltage sensor 21 is abnormal by the device), when the resistance element having the smallest resistance value among the many resistance elements R1 to Rn, r connected in series fails. The resistance of the resistance element is set so that the input voltage conversion value obtained from the output signal of the INV voltage sensor 21 does not overlap with the input voltage conversion value obtained from the output signal of the B / C voltage sensor 22 including an error range. Value is set. That is, the input voltage conversion value obtained from the output signal of the INV voltage sensor 21 when the resistance element having the minimum resistance value provided in the INV voltage sensor 21 fails is always B / C even if the error range is taken into consideration. The resistance value of the resistance element included in the INV voltage sensor 21 is set so as to be different from the input voltage converted value obtained from the output signal of the voltage sensor 22.

  Hereinafter, a setting example of the resistance value of the resistance element included in the INV voltage sensor 21 configured as the voltage dividing circuit will be specifically described.

  In the example of FIG. 3, the output signal (voltage VA) of the INV voltage sensor 21 at normal time and a short-circuit fault (manufacturing failure) in the resistance element (here, the resistance element Rn) having the smallest resistance value among the resistance elements R1 to Rn. The output signal (voltage VA) of the INV voltage sensor 21 is calculated.

Here, the premise of calculation is as follows.
・ Battery voltage VBAT = 300V
-Number of resistance elements R1 to Rn: 10-Resistance element causing short circuit failure: Resistance element Rn
Resistance value per one of the resistance elements R1 to Rn-1: 30 kΩ (Here, the resistance values of the resistance elements R1 to Rn-1 are all the same, and hereinafter, the resistance value is expressed as R.)
-Resistance value of resistance element r: 10 kΩ
・ Conversion error of voltage sensors 21 and 22 (error range allowed as tolerance): ± 3%

Based on this assumption, assuming that the resistance value of the resistance element Rn causing the short-circuit failure is 5 kΩ, the output signal when the INV voltage sensor 21 is normal and the output signal when the short-circuit fault of the resistance element Rn are calculated. The output signal (voltage VA) is as follows.
Normal: VA = r / (r + 9R + Rn) × VBAT = 10 kΩ / (10 kΩ + 9 × 30 kΩ + 5 kΩ) × 300 V = 10.53 V
At the time of Rn short-circuit failure: VA = r / (r + 9R) × VBAT = 10 kΩ / (10 kΩ + 9 × 30 kΩ) × 300 V = 10.71 V

From this result, when the resistance value of the resistance element Rn is 5 kΩ, the converted value of the input voltage of the INV voltage sensor 21 when the resistance element Rn is short-circuited (obtained by the motor controller 7 based on the output signal of the INV voltage sensor 21). The nominal value of the battery voltage is as follows.
10.71V / 10.53V × 300V = 305.1V
Therefore, in consideration of the error ± 3%, the range that the input voltage converted value of the INV voltage sensor 21 can take when the resistance element Rn is short-circuited is 295.9V to 314.3V.

  On the other hand, the input voltage converted value of the INV voltage sensor 21 at the normal time is equal to the input voltage converted value of the B / C voltage sensor 22 (300 V), and the range that these input voltage converted values can take when an error of ± 3% is considered. Becomes 291V to 309V.

  As described above, when the resistance value of the resistance element Rn of the INV voltage sensor 21 is 5 kΩ, the range that the input voltage conversion value of the INV voltage sensor 21 can take when the resistance element Rn is short-circuited, and the B / C voltage sensor Since the range that can be taken by the input voltage converted value of 22 partially overlaps (range of 295.9V to 309V), if the input voltage converted value of the INV voltage sensor 21 is within this overlapping range, this INV voltage Even if the input voltage converted value of the sensor 21 is compared with the input voltage converted value of the B / C voltage sensor 22, it is not possible to correctly determine whether the INV voltage sensor 21 is abnormal.

Next, when the resistance value of the resistance element Rn causing the short-circuit failure is set to 30 kΩ, the output signal when the INV voltage sensor 21 is normal and the output signal when the resistance element Rn is short-circuited are calculated in the same manner as described above. Each output signal (voltage VA) is as follows.
Normal: VA = r / (r + 9R + Rn) × VBAT = 10 kΩ / (10 kΩ + 9 × 30 kΩ + 30 kΩ) × 300 V = 9.68 V
At the time of Rn short-circuit failure: VA = r / (r + 9R) × VBAT = 10 kΩ / (10 kΩ + 9 × 30 kΩ) × 300 V = 10.71 V

From this result, the nominal value of the input voltage converted value of the INV voltage sensor 21 when the resistance value of the resistance element Rn is 30 kΩ and the resistance element Rn is short-circuited is as follows.
10.71V / 9.68V × 300V = 331.9V
Therefore, when the error ± 3% is taken into consideration, the input voltage conversion value of the INV voltage sensor 21 when the resistance element Rn is short-circuited can be 321.9V to 341.9V. There is no overlap with respect to 291V to 309V, which is a range in which the voltage conversion value can be taken (a range in which the input voltage conversion value of the B / C voltage sensor 22 can take).

  From the above, under the above-mentioned preconditions, by setting the resistance value of the resistance element Rn to 30 kΩ, the input voltage conversion value of the INV voltage sensor 21 and the input voltage conversion value of the B / C voltage sensor 22 are reduced. It can be seen from the comparison that the presence or absence of abnormality of the INV voltage sensor 21 can be correctly determined. That is, by setting the resistance value of the resistance element Rn of the INV voltage sensor 21 as described above, for example, as shown in FIG. 4, the upper limit value of the range that can be taken by the input voltage conversion value of the INV voltage sensor 21 at normal time 309V, which is the upper limit of the range that the input voltage conversion value of the B / C voltage sensor 22 can take, and the lower limit of the range that the input voltage conversion value of the INV voltage sensor 21 can take when the resistance element Rn is short-circuited A threshold for abnormality determination can be provided between a certain 321.9V (for example, 315V), the input voltage converted value of the B / C voltage sensor 22 is less than the threshold, and the input voltage of the INV voltage sensor 21 When the converted value exceeds the threshold value, it can be determined that an abnormality has occurred in the INV voltage sensor 21.

  The output signal of the INV voltage sensor 21, that is, the battery voltage of the high voltage battery 9 monitored by the INV voltage sensor 21, as described above, the d and q axes to the motor generator 1 in the current command unit 13 of the motor controller 7. Used to set current command values id * and iq *. Here, when the motor controller 7 detects the abnormality of the INV voltage sensor 21 by the above-described method, the current command unit 13 uses the predetermined minimum value of the battery voltage instead of the output signal of the INV voltage sensor 21. If the d and q-axis current command values id * and iq * are set in step S1, the d and q-axis current command values id * and iq * are continuously set even when the INV voltage sensor 21 is abnormal. Thus, the operation can be continued without stopping the inverter 8.

  As described above in detail with specific examples, in the present embodiment, the resistance element Rn having the smallest resistance value among the many resistance elements R1 to Rn of the INV voltage sensor 21 has failed. The input voltage conversion value (battery voltage) obtained from the output signal of the INV voltage sensor 21 overlaps the input voltage conversion value (battery voltage) obtained from the output signal of the B / C voltage sensor 22 including an error range. In order to avoid this, the resistance values of the resistance elements R1 to Rn of the INV voltage sensor 21 (in the specific example described above, the resistance value of the resistance element Rn) are set. Therefore, when an abnormality occurs in the INV voltage sensor 21, the input voltage conversion value of the INV voltage sensor 21 is always different from the input voltage conversion value of the B / C voltage sensor 22, so a new circuit for detecting an abnormality is obtained. The abnormality of the INV voltage sensor 21 can be accurately detected by comparing these values without adding the above. Even if the cause of the abnormality of the INV voltage sensor 21 is a failure of the resistance element having the smallest resistance value, the input voltage converted value of the INV voltage sensor 21 is always the input voltage conversion value of the B / C voltage sensor 22. Since the values are different, the abnormality can be reliably detected even when the INV voltage sensor 21 is abnormal due to a failure of another resistance element.

  Further, when the abnormality of the INV voltage sensor 21 is detected, the motor controller 7 performs control by using the lowest value of the battery voltage instead of the output signal of the INV voltage sensor 21, so that the inverter 8 is not stopped. The operation can be continued.

  In the above description, the input voltage converted value of the INV voltage sensor 21 configured as a voltage dividing circuit is compared with the input voltage converted value of the B / C voltage sensor 22 that monitors the same battery voltage as the INV voltage sensor 21. However, the abnormality of the INV voltage sensor 21 is determined by simply comparing the input voltage converted value of the INV voltage sensor 21 with a predetermined reference value (corresponding to the threshold value for determining the abnormality described above). It is also possible to do. In this case, the predetermined reference value is set to a value higher than the upper limit value of the range that the input voltage conversion value of the INV voltage sensor 21 can take when it is normal, and the resistance value among the many resistance elements of the INV voltage sensor 21 is The possible range of the input voltage converted value of the INV voltage sensor 21 when the smallest resistive element fails is not overlapped with this reference value, that is, even if the input voltage converted value of the INV voltage sensor 21 takes into account an error. The resistance value of the resistance element of the INV voltage sensor 21 is set so that the value always exceeds the reference value. By setting the resistance value of the resistance element of the INV voltage sensor 21 in this way, it is possible to accurately detect an abnormality in the INV voltage sensor 21 by comparing the input voltage converted value of the INV voltage sensor 21 with a predetermined reference value. it can.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The present embodiment is a setting example of resistance values when it is assumed that the resistance values of the resistance elements R1 to Rn included in the INV voltage sensor 21 are equal to each other. The configuration and circuit configuration of the drive system are the same as those described in the first embodiment (see FIGS. 1 to 3).

In the present embodiment, the total resistance value of the resistance elements R1 to Rn included in the INV voltage sensor 21 is 200 kΩ, and the resistance values of the resistance elements R1 to Rn are equal. Further, the resistance element in which the short-circuit failure occurs is any one of the resistance elements R1 to Rn, and other preconditions are the same as those in the first embodiment. Under such a premise, it is assumed that the number of resistance elements R1 to Rn is 20 and the resistance value per resistance element is 10 kΩ, and any of the output signal and the resistance elements R1 to Rn when the INV voltage sensor 21 is normal. When the output signal at the time of one short circuit failure is calculated, each output signal (voltage VA) is as follows.
Normal: VA = r / (r + 20R) × VBAT = 10 kΩ / (10 kΩ + 20 × 10 kΩ) × 300 V = 14.3 V
At the time of short circuit failure: VA = r / (r + 19R) × VBAT = 10 kΩ / (10 kΩ + 19 × 10 kΩ) × 300 V = 15.0 V

From this result, when the number of the resistance elements R1 to Rn is 20 and the resistance value per one is 10 kΩ, the input of the INV voltage sensor 21 when a short circuit failure occurs in any one of the resistance elements R1 to Rn. The nominal value of the voltage conversion value (battery voltage grasped by the motor controller 7 based on the output signal of the INV voltage sensor 21) is as follows.
15.0V / 14.3V × 300V = 314.7V
Therefore, when an error of ± 3% is taken into consideration, the input voltage conversion value of the INV voltage sensor 21 when a short circuit failure occurs in any one of the resistance elements R1 to Rn can be 305.2V to 324.2V. The range of 305.2V to 309V with respect to 291V to 309V, which is the range that the input voltage converted value of the INV voltage sensor 21 can take (the range that the input voltage converted value of the B / C voltage sensor 22 can take) at normal time Will be duplicated. For this reason, if the input voltage conversion value of the INV voltage sensor 21 is within this overlapping range, the INV voltage sensor 21 input voltage conversion value is compared with the input voltage conversion value of the B / C voltage sensor 22. Whether the voltage sensor 21 is abnormal cannot be determined correctly.

Next, in the case where the number of the resistance elements R1 to Rn is 10 and the resistance value per one is 20 kΩ, any one of the output signal and the resistance elements R1 to Rn when the INV voltage sensor 21 is normal as described above. If the output signal at the time of one short circuit failure is calculated, each output signal (voltage VA) will be as follows.
Normal: VA = r / (r + 10R) × VBAT = 10 kΩ / (10 kΩ + 10 × 20 kΩ) × 300 V = 14.3 V
At the time of short circuit failure: VA = r / (r + 9R) × VBAT = 10 kΩ / (10 kΩ + 9 × 20 kΩ) × 300 V = 15.8V

From this result, when the number of resistance elements R1 to Rn is 10 and the resistance value per one is 20 kΩ, the input of the INV voltage sensor 21 at the time of a short circuit failure of any one of the resistance elements R1 to Rn. The nominal value of the voltage conversion value is as follows.
15.8V / 14.3V × 300V = 331.5V
Therefore, in consideration of the error ± 3%, the range that the input voltage converted value of the INV voltage sensor 21 can take when any one of the resistance elements R1 to Rn is short-circuited is 321.5V to 341.5V, which is normal. Therefore, there is no overlap with 291V to 309V, which is a range that the input voltage converted value of the INV voltage sensor 21 can take (a range that the input voltage converted value of the B / C voltage sensor 22 can take).

  From the above, under the above preconditions, the number of resistance elements R1 to Rn is 10, and the resistance value per resistance element R1 to Rn is 20 kΩ, so that the input of the INV voltage sensor 21 It can be seen that the presence or absence of abnormality of the INV voltage sensor 21 can be correctly determined by comparing the converted voltage value with the converted input voltage value of the B / C voltage sensor 22. That is, by setting the number of the resistance elements R1 to Rn and the resistance value per one as described above, the upper limit value (B / C voltage) of the range that the input voltage conversion value of the INV voltage sensor 21 can take at normal time. 309V, which is the upper limit of the range that the input voltage conversion value of the sensor 22 can take), and the lower limit of the range that the input voltage conversion value of the INV voltage sensor 21 can take when any one of the resistance elements R1 to Rn is short-circuited A threshold for abnormality determination can be provided between the value of 321.5 V (for example, 315 V), the input voltage conversion value of the B / C voltage sensor 22 is less than the threshold, and the INV voltage sensor 21 When the input voltage conversion value exceeds the threshold value, it can be determined that an abnormality has occurred in the INV voltage sensor 21.

  As described above in detail with specific examples, according to the present embodiment, when an abnormality occurs in the INV voltage sensor 21, the input voltage conversion value of the INV voltage sensor 21 is changed to that of the B / C voltage sensor 22. Since the input voltage conversion value is always different from the input voltage conversion value, the INV voltage sensor 21 can be compared by comparing these values without adding a new circuit or the like for detecting an abnormality, as in the first embodiment. Abnormalities can be detected with high accuracy. Further, when an abnormality of the INV voltage sensor 21 is detected, as in the first embodiment, the motor controller 7 performs control using the lowest value of the battery voltage instead of the output signal of the INV voltage sensor 21. The operation can be continued without stopping the inverter 8.

  In the present embodiment, the resistance values of the resistance elements R1 to Rn included in the INV voltage sensor 21 are set to the same value, so that the circuit design becomes easy.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. In this embodiment, when a short circuit abnormality occurs in the voltage dividing resistor of the INV voltage sensor 21 that is a voltage dividing circuit, the input voltage conversion value of the INV voltage sensor 21 is stored as a short-circuit occurrence voltage, and the actual INV When the input voltage conversion value obtained from the output signal of the voltage sensor 21 is equal to the stored short-circuit occurrence voltage, it is determined that a short-circuit abnormality has occurred in the voltage dividing resistor of the INV voltage sensor 21, and the INV voltage sensor The input voltage conversion value obtained from the output signal 21 is corrected with a correction value corresponding to the short circuit abnormality. Note that the configuration and circuit configuration of the drive system are basically the same as those described in the first embodiment (see FIGS. 1 and 2). However, in this embodiment, as shown in FIG. 5, the battery controller 10 is provided with a function (abnormality determination unit 23) for determining an abnormality of the INV voltage sensor 21. That is, the output signal of the INV voltage sensor 21 is transmitted from the motor controller 7 to the battery controller 10 via the CAN line, and the abnormality determination unit 23 of the battery controller 10 converts the input voltage converted value of the INV voltage sensor 21 to B / C. Compared with the input voltage conversion value of the voltage sensor 22, the presence or absence of abnormality of the INV voltage sensor 21 is determined.

  Hereinafter, on the premise of the configuration of the INV voltage sensor 21 described as a specific example in the first embodiment, characteristic technical matters in the present embodiment will be described.

  The voltage dividing resistance of the INV voltage sensor 21 has 10 resistance elements R1 to Rn, and the resistance value per resistance element R1 to Rn is 30 kΩ, as described as a specific example in the first embodiment. Suppose that In this case, when the battery voltage VBAT = 300V, the nominal value of the input voltage conversion value of the INV voltage sensor 21 at the time of a short circuit failure of any one of the resistance elements R1 to Rn is 331.9V, and the input voltage conversion of the INV voltage sensor 21 The range that the value can take is 321.9V to 341.9V. The abnormality determination unit 23 of the battery controller 10 stores this value as a short-circuit occurrence voltage. The abnormality determination unit 23 does not necessarily need to store the voltage value itself as described above. For example, the abnormality determination unit 23 may store a voltage ratio between a normal time and an abnormal time.

  The abnormality determination unit 23 of the battery controller 10 compares the input voltage converted value of the INV voltage sensor 21 with the input voltage converted value of the B / C voltage sensor 22 as needed, and when a significant difference occurs between these values. It is determined that an abnormality has occurred in the INV voltage sensor 21. Then, it is checked whether or not the input voltage converted value of the INV voltage sensor 21 at that time is equal to a pre-stored voltage at the time of occurrence of a short circuit, and if so, a short circuit abnormality occurs in the voltage dividing resistor of the INV voltage sensor 21. Therefore, the voltage sensor abnormality signal is output to the inverter 8.

  When the voltage sensor abnormality signal is input from the abnormality determination unit 23 of the battery controller 10, the inverter 8 determines that a short-circuit abnormality has occurred in the voltage dividing resistor of the INV voltage sensor 21, and outputs the output signal of the INV voltage sensor 21. The correction is made with a correction coefficient corresponding to the short circuit abnormality, and output to the current command unit 13 of the motor controller 7. Specifically, the output signal of the INV voltage sensor 21 is converted into a small value by a ratio of 300V / 331.9V and output. As a result, the current command unit 13 of the motor controller 7 sets the current command values id * and iq * from the current table based on the corrected output signal of the INV voltage sensor 21, and the operation of the motor controller 7. Will continue.

  As described above in detail with specific examples, according to the present embodiment, when the input voltage converted value of the INV voltage sensor 21 is equal to the pre-stored short-circuit occurrence voltage, the INV voltage sensor 21 Since it is determined that a short circuit abnormality has occurred in the voltage dividing resistor, the output signal of the INV voltage sensor 21 is corrected with a correction coefficient corresponding to the short circuit abnormality and used for control by the motor controller 7. Even when a short circuit abnormality occurs in the voltage dividing resistor of the INV voltage sensor 21, the operation of the motor controller 7 can be continued without causing a reduction in efficiency in the inverter 8. That is, in the first embodiment and the second embodiment described above, when the abnormality of the INV voltage sensor 21 occurs, the motor controller 7 performs control using the minimum value of the battery voltage instead of the output signal of the INV voltage sensor 21. However, in this embodiment, the operation in the motor controller 7 can be continued without causing such a decrease in efficiency in the inverter 8.

  In the present embodiment, whether the INV voltage sensor 21 is abnormal or not is determined by the abnormality determination unit 23 provided in the battery controller 10, but as in the first and second embodiments, The motor controller 7 or other control device may determine whether the INV voltage sensor 21 is abnormal.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. The present embodiment is an example in which not only the INV voltage sensor 21 but also the B / C voltage sensor 22 is configured as a voltage dividing circuit, and when the short circuit abnormality occurs in the voltage dividing resistor of the INV voltage sensor 21 Each voltage so that the input voltage conversion value of the INV voltage sensor 21 and the input voltage conversion value of the B / C voltage sensor 22 when a short circuit abnormality occurs in the voltage dividing resistor of the B / C voltage sensor 22 do not overlap. The series number of resistance elements constituting the voltage dividing circuit of the sensors 21 and 22 is set. Note that the configuration and circuit configuration of the drive system are basically the same as those described in the first embodiment (see FIGS. 1 and 2). However, in the present embodiment, as shown in FIG. 6, the B / C voltage sensor 22 is configured as a voltage dividing circuit, and the voltage dividing resistance formed by connecting the resistance elements R11 to R16 and the resistance element r2 in series is higher. By dividing the battery voltage VBAT of the voltage battery 9, a voltage VB proportional to the battery voltage VBAT is generated as an output signal.

  Hereinafter, on the assumption of the configuration of the INV voltage sensor 21 described as a specific example in the first embodiment, a setting example of the series number of resistance elements included in the B / C voltage sensor 22 will be specifically described.

The voltage dividing resistance of the INV voltage sensor 21 has 10 resistance elements R1 to Rn, and the resistance value per resistance element R1 to Rn is 30 kΩ, as described as a specific example in the first embodiment. Suppose that On the other hand, the voltage dividing resistor of the B / C voltage sensor 22 has six resistance elements (resistance elements R11 to R16) having the same resistance value connected in series, and the resistance value per one of the resistance elements R11 to R16 is 50 kΩ. Suppose that The resistance value of the resistance element r2 connected to the ground of the B / C voltage sensor 22 is 10 kΩ, which is the same as the resistance value of the resistance element r1 connected to the ground of the INV voltage sensor 21. Under such a premise, when the output signal when the B / C voltage sensor 22 is normal and the output signal when one of the resistance elements R11 to R16 is short-circuited are calculated, each output signal (voltage VB) is calculated. Is as follows.
Normal: VB = r2 / (r2 + 6R) × VBAT = 10 kΩ / (10 kΩ + 6 × 50 kΩ) × 300 V = 9.68 V
At the time of short circuit failure: VB = r2 / (r2 + 5R) × VBAT = 10 kΩ / (10 kΩ + 5 × 50 kΩ) × 300 V = 11.54 V

From this result, when the voltage dividing resistance of the B / C voltage sensor 22 is connected in series with six resistance elements R11 to R16 having the same resistance value, and the resistance value per one is 50 kΩ, the resistance element The nominal value of the input voltage conversion value of the B / C voltage sensor 22 at the time of any one short circuit failure of R11 to R16 is as follows.
11.54V / 9.68V × 300V = 357.6V
Therefore, in consideration of the error ± 3%, the range that the input voltage conversion value of the B / C voltage sensor 22 can take when any one of the resistor elements R11 to R16 is short-circuited is 346.8V to 368.3V, It does not overlap with 291V to 309V, which is a range that can be taken by the input voltage converted value of the B / C voltage sensor 22 at normal time (a range that can be taken by the input voltage converted value of the INV voltage sensor 21 at normal time). The input voltage conversion value of the INV voltage sensor 21 at the time of a short-circuit failure of any one of the resistance elements R1 to R10 does not overlap with 321.9V to 341.9V which is a possible range.

  In the above example, the difference between the B / C voltage sensor 22 and the INV voltage sensor 21 is only the number of series of resistance elements constituting the voltage dividing resistor. That is, when the series number of resistance elements of the B / C voltage sensor 22 is the same as that of the INV voltage sensor 21, an abnormality occurs in which one resistance element is short-circuited in both the B / C voltage sensor 22 and the INV voltage sensor 21. In addition, since no significant difference occurs between the two input voltage conversion values, an abnormality cannot be detected. However, both the B / C voltage sensor 22 and the INV voltage sensor 21 are intentionally different in the series number of resistance elements between the B / C voltage sensor 22 and the INV voltage sensor 21 as in the present embodiment. Even when a short circuit abnormality occurs, a significant difference occurs between the input voltage conversion values of both, and the abnormality can be detected. As a specific example, in this embodiment, the number of resistance elements R of the INV voltage sensor 21 is set to 10 and the number of resistance elements R of the B / C voltage sensor 22 is set to 6, so that the B / C voltage sensor 22 and the INV voltage are set. Even if a short circuit abnormality occurs in both of the sensors 21, the abnormality can be detected.

  As described above in detail with specific examples, according to the present embodiment, when the short-circuit abnormality occurs in the voltage dividing resistor of the INV voltage sensor 21, the input voltage converted value of the INV voltage sensor 21 is The voltage dividing circuits of the voltage sensors 21 and 22 are configured so that the input voltage conversion value of the B / C voltage sensor 22 does not overlap when a short circuit abnormality occurs in the voltage dividing resistor of the B / C voltage sensor 22. Therefore, even if a short circuit abnormality occurs in both the INV voltage sensor 21 and the B / C voltage sensor 22, the input voltage conversion value of the INV voltage sensor 21 and the B / C By comparing with the input voltage conversion value of the C voltage sensor 22, the abnormality can be detected with high accuracy. Even if the cause of the abnormality of the INV voltage sensor 21 or the cause of the abnormality of the B / C voltage sensor 22 is a failure of the resistance element having the smallest resistance value, the input voltage converted value of the INV voltage sensor 21 and the B / C voltage Since the input voltage conversion value of the sensor 22 is always different from that of the sensor 22, even if the INV voltage sensor 21 or the B / C voltage sensor 22 is abnormal due to a failure of another resistive element, the abnormality is reliably detected. can do.

  Each of the above embodiments is an example of an application of the present invention, and the technical scope of the present invention is not intended to be limited to the contents described as these embodiments. In other words, the technical scope of the present invention is not limited to the specific technical matters disclosed in the above embodiments, but includes various modifications, changes, alternative techniques, and the like that can be easily derived from this disclosure.

  For example, in each of the above-described embodiments, the number and resistance values of the resistive elements constituting the voltage dividing circuit of the INV voltage sensor 21, the number of resistive elements and the resistance value when the B / C voltage sensor 22 is a voltage dividing circuit, etc. However, these specific configurations can be appropriately changed without departing from the spirit of the present invention as grasped by the description of the scope of claims. In addition, each of the above embodiments is an application example as an abnormality detection device that detects an abnormality when the abnormality occurs in the voltage sensors 21 and 22 for monitoring the battery voltage of the high voltage battery 9 mounted on the hybrid vehicle. However, the present invention is not limited to the above example, and can be widely applied in applications for detecting an abnormality in an electric circuit having at least one voltage dividing circuit.

1 is a system configuration diagram showing an example of a hybrid vehicle drive system. FIG. It is a block diagram of the control system regarding a motor generator. It is a figure explaining the 1st Embodiment of this invention, and is an example of the simple circuit diagram which extracted the INV voltage sensor, B / C voltage sensor, and its peripheral part which were shown in FIG.1 and FIG.2. Explains the relationship between the range that the input voltage converted value of the INV voltage sensor can take in normal time, the range that the input voltage converted value of the INV voltage sensor can take when the resistance element Rn is short-circuited, and the threshold value for abnormality determination It is a figure to do. It is a figure explaining the 3rd Embodiment of this invention, and is the other example of the simplified circuit diagram which extracted the INV voltage sensor and B / C voltage sensor which were shown in FIG.1 and FIG.2, and its peripheral part. It is a figure explaining the 4th Embodiment of this invention, and is still another example of the simplified circuit diagram which extracted the INV voltage sensor, B / C voltage sensor, and its peripheral part which were shown in FIG.1 and FIG.2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor generator 7 Motor controller 8 Inverter 9 High voltage battery 10 Battery controller 21 INV voltage sensor 22 B / C voltage sensor 23 Abnormality judgment part

Claims (6)

A plurality of circuits for generating an output signal based on the same input voltage;
A determination means for determining an abnormality by comparing an input voltage converted value obtained by converting the output signals of the plurality of circuits into an input voltage;
At least one of the plurality of circuits is a voltage dividing circuit that divides an input voltage by a voltage dividing resistor including a plurality of resistance elements connected in series to generate an output signal,
The input voltage conversion value obtained from the output signal of the voltage dividing circuit when the resistance element having the smallest resistance value out of the plurality of resistance elements possessed by the voltage dividing circuit is an input obtained from the output signal of another circuit. An abnormality detection apparatus, wherein a resistance value of a resistance element of the voltage dividing circuit is set so as not to overlap with a voltage conversion value including an error range. A voltage dividing circuit that divides an input voltage by a voltage dividing resistor including a plurality of resistance elements connected in series to generate an output signal;
Determination means for determining an abnormality based on an input voltage converted value obtained by converting an output signal of the voltage dividing circuit into an input voltage;
The input voltage conversion value obtained from the output signal when the resistance element having the smallest resistance value among the plurality of resistance elements possessed by the voltage dividing circuit does not overlap with the predetermined reference value including the error range. Further, a resistance value of a resistance element of the voltage dividing circuit is set.   The abnormality detection device according to claim 1, wherein resistance values of the plurality of resistance elements included in the voltage dividing circuit are equal.   The determination means stores an input voltage converted value obtained from an output signal when a short circuit abnormality occurs in the voltage dividing resistor of the voltage dividing circuit as a voltage at the time of occurrence of a short circuit, and is obtained from the output signal of the voltage dividing circuit. When the converted input voltage value is equal to the short-circuit occurrence voltage, it is determined that a short-circuit abnormality has occurred in the voltage dividing resistor of the voltage dividing circuit, and the output signal of the voltage dividing circuit is corrected according to the short-circuit abnormality. The abnormality detection device according to claim 1, wherein the abnormality detection device corrects the error. The voltage dividing circuit includes two circuits, a first voltage dividing circuit and a second voltage dividing circuit,
An input voltage conversion value obtained from an output signal of the first voltage dividing circuit when a resistance element having the smallest resistance value among the plurality of resistance elements of the first voltage dividing circuit fails; and In order not to overlap the input voltage conversion value obtained from the output signal of the second voltage dividing circuit when the resistance element having the smallest resistance value among the plurality of resistance elements possessed by the voltage dividing circuit fails. 2. The abnormality detection device according to claim 1, wherein a series number of resistor elements of the voltage divider circuit and a series number of resistor elements of the second voltage divider circuit are set.   The abnormality detection device according to claim 1, wherein the voltage dividing circuit is a high voltage monitor circuit that monitors a voltage of a high voltage battery mounted on the electric vehicle.

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