Abnormality monitoring apparatus in load drive circuit

• US 7,432,719 B2
• Filed: 10/29/2004
• Issued: 10/07/2008
• Est. Priority Date: 11/19/2003
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Nozaki, Takeshi
• Primary Examiner(s): Nguyen; Vincent Q
• Application Number:
  US10/579,212
• Publication Number:
  US 20070120530A1
• Time in Patent Office: 1,439 Days
• Field of Search: 324/522, 324/433, 324/429, 324/432
• US Class Current: 324/522
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/005 Testing of electric installations on transport means
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: H02J 7/00308 Overvoltage protection
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/14 for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

An ECU performs a program. In the program, in the case where a converter is performing an operation for increasing a voltage (i.e., YES in step S 102), when a difference between an estimated battery voltage VBE and a battery voltage VB has continued to be large (i.e., YES in step S 104), the ECU tentatively determines that a battery voltage sensor is abnormal (S 106), and stops voltage increasing control for the converter (S 108). If an absolute value of a difference between a battery voltage and an output side voltage is large (i.e., YES in step S 110), a difference A which is an absolute value between an estimated battery voltage and a battery voltage, and a difference B which is an absolute value between the estimated battery voltage and an output side voltage are calculated (S 112). If a value obtained by subtracting the difference B from the difference A has continued to be large (i.e., YES in step S 114), it is determined that the battery voltage sensor is abnormal (S 116). If a voltage obtained by subtracting the difference A from the difference B has continued to be large (i.e., YE in step S 118), it is determined that the output side voltage sensor is abnormal (S 120).

Claims

1. An abnormality monitoring apparatus in a load drive circuit which includes a converter for performing at least one of an operation for increasing a voltage and an operation for decreasing a voltage, and a battery connected to an input side of the converter, the converter supplying electric power to a load, the abnormality monitoring apparatus comprising:

first detecting means for detecting a voltage value of the battery;

second detecting means for detecting a voltage value on an output side of the converter;

battery voltage estimating means for calculating an estimated voltage value of the battery;

calculating means for calculating at least one of the difference value between the voltage value detected by the first detecting means and the estimated voltage value, and the difference value between the voltage value detected by the second detecting means and the estimated voltage value; and

monitoring means for monitoring at least one of an abnormality of the first detecting means and an abnormality of the second detecting means based on each of the difference values and a predetermined threshold value.

2. The abnormality monitoring apparatus according to claim 1, wherein the monitoring means includes abnormality detecting means for detecting an abnormality of the first detecting means based on an absolute value of the difference between the voltage value of the battery detected by the first detecting means and the estimated voltage value in a case where the converter is performing the operation for increasing the voltage or the operation for decreasing the voltage.

3. The abnormality monitoring apparatus according to claim 1, further comprising control means for controlling the converter such that the converter stops the operation for increasing the voltage or the operation for decreasing the voltage when an abnormality of the first detecting means is tentatively detected in a case where the converter is performing the operation for increasing the voltage or the operation for decreasing the voltage, wherein the monitoring means includes determining means for determining which one of the first detecting means and the second detecting means is abnormal based on an absolute value of the difference between the voltage value of the battery detected by the first detecting means and the estimated voltage value, and an absolute value of the difference between the voltage value detected by the second detecting means and the estimated voltage value when the converter stops the operation for increasing the voltage or the operation for decreasing the voltage.

4. The abnormal monitoring apparatus according to claim 1, further comprising electric current value detecting means for detecting an electric current value of the battery, wherein the battery voltage estimating means includes estimated voltage value calculating means for calculating the estimated voltage value based on an electric power command value indicating a value of electric power supplied to the load and the electric current value of the battery.

5. The abnormal monitoring apparatus according to claim 4, wherein the battery voltage estimating means includes estimated voltage value learning calculating means for learning and calculating the estimated voltage value.

6. The abnormal monitoring apparatus according to claim 1, wherein the monitoring means includes abnormality monitoring means for monitoring an abnormality of at least one of the first detecting means and the second detecting means by continuing to monitor an abnormal state of at least one of the first detecting means and the second detecting means for a predetermined time or more.

7. An abnormality monitoring method in a load drive circuit which includes a converter for performing at least one of an operation for increasing a voltage and an operation for decreasing a voltage, and a battery connected to an input side of the converter, the converter supplying electric power to a load, the abnormality monitoring apparatus comprising the steps of:

detecting a voltage value of the battery;

detecting a voltage value on an output side of the converter;

calculating an estimated voltage value of the battery;

calculating at least one of the difference value between the detected voltage value of the battery and the estimated voltage value, and the difference value between the detected voltage value on the output side of the converter and the estimated voltage value; and

monitoring at least one of an abnormality of detection of the voltage value of the battery and an abnormality of detection of the voltage value on the output side of the converter based on each of the difference values and a predetermined threshold value.

8. An abnormality monitoring apparatus in a load drive circuit which includes a converter for performing at least one of an operation for increasing a voltage and an operation for decreasing a voltage, and a battery connected to an input side of the converter, the converter supplying electric power to a load, the abnormality monitoring apparatus comprising:

a first detector that detects a voltage value of the battery;

a second detector that detects a voltage value on an output side of the converter;

a battery voltage estimating portion which calculates an estimated voltage value of the battery;

a calculating portion which calculates at least one of the difference value between the voltage value detected by the first detector and the estimated voltage value, and the difference value between the voltage value detected by the second detector and the estimated voltage value; and

a monitoring portion which monitors at least one of an abnormality of the first detector and an abnormality of the second detector based on each of the difference values and a predetermined threshold value.

9. The abnormality monitoring apparatus according to claim 8, wherein the monitoring portion includes an abnormality detector that detects an abnormality of the first detector based on an absolute value of the difference between the voltage value of the battery detected by the first detector and the estimated voltage value in a case where the converter is performing the operation for increasing the voltage or the operation for decreasing the voltage.

10. The abnormality monitoring apparatus according to claim 8, further comprising a controller that controls the converter such that the converter stops the operation for increasing the voltage or the operation for decreasing the voltage when an abnormality of the first detector is tentatively detected in a case where the converter is performing the operation for increasing the voltage or the operation for decreasing the voltage, wherein the monitoring portion includes a determining portion that determines which one of the first detector or the second detector is abnormal based on an absolute value of the difference between the voltage value of the battery detected by the first detector and the estimated voltage value, and an absolute value of the difference between the voltage value detected by the second detector and the estimated voltage value when the converter stops the operation for increasing the voltage or the operation for decreasing the voltage.

11. The abnormal monitoring apparatus according to claim 8, further comprising an electric current value detector that detects an electric current value of the battery, wherein the battery voltage estimating portion includes an estimated voltage value calculating portion that calculates the estimated voltage value based on an electric power command value indicating a value of electric power supplied to the load and the electric current value of the battery.

12. The abnormal monitoring apparatus according to claim 11, wherein the battery voltage estimating portion includes an estimated voltage value learning calculating portion that learns and calculates the estimated voltage value.

13. The abnormal monitoring apparatus according to claim 8, wherein the monitoring portion includes an abnormality monitoring portion that monitors an abnormality of at least one of the first detector and the second detector by continuing to monitor an abnormal state of at least one of the first detector and the second detector for a predetermined time or more.