KR-102963370-B1 - Method for detecting insulation failures in automobiles

Abstract

A method (1) for detecting insulation failure of an electric battery suitable for obtaining an insulation resistance value (R i ) from a detection device is disclosed, and the method (1) for detecting insulation failure of an electric battery includes a series of steps for optimizing the switching period (T) of a switch (S 1 ) of a device for detecting the insulation resistance value (R i ).

Inventors

• 할랄치 후??

Assignees

• 암페르 에스.아.에스.

Dates

Publication Date

20260508

Application Date

20221024

Priority Date

20211104

Claims (7)

1. A method (1) for detecting insulation failure of a storage battery, designed to obtain an insulation resistance value (R i ) from a detection device, The detection device is connected to a battery terminal on one side and to ground on the other; it includes a current limiting resistor ( Rd ), a filtering resistor ( Rm ), and a voltage source ( Ud ) in series, and includes a filtering capacitor ( Cm ) connected in parallel with the filtering resistor ( Rm ). The above voltage source (U d ) includes a permanent source (U ref ) and another source (U d0 ) that can be actuated by a switch (S 1 ) connected in parallel with the terminals; The method (1) for detecting insulation failure of the above-described storage battery detects insulation failure based on an insulation resistance value ( R i ) obtained according to measurements from the current limiting resistor (R d ), the filtering resistor (R m), and the filtering capacitor (C m ); These measurements are obtained for two individual values of the voltage source (U d ) that are periodically generated by the step (121) of switching the switch (S 1 ); The method (1) for detecting insulation failure of the above-described storage battery implements a series of steps to optimize the switching period (T) of the above-described switch ( S1 ), and The above series of steps are, - A step of initializing a time counter (T v ) and a switching period (T) of the switch (S 1 ); and in one loop (130), in successive increments (t-1, t, t+1) at intervals of a predetermined period (Δ T ), o Measure the voltage across the terminals of the above filtering resistor (R m ) (120); o Calculate the change in measured voltage between the current increment (t) and the previous increment (t-1) (132); o If the above calculated change is greater than a predetermined threshold, the time counter (T v ) is incremented (134) by the predetermined period (Δ T ); and o If the above calculated change is lower than the above predetermined threshold value, the step of defining the switching period (T) as equal to the value of the time counter (T v ) (133); A method for detecting insulation failure of a storage battery, characterized by including
2. In paragraph 1, A method for detecting insulation failure in a storage battery, characterized in that when the above change is lower than the above-determined threshold, a safety time margin (m) is also added to the above-determined switching period (T).
3. In paragraph 1 or 2, A method for detecting insulation failure of a battery, characterized in that a series of steps for optimizing the switching period (T) are implemented when the battery is turned on.
4. In paragraph 1 or 2, A method for detecting insulation failure in a storage battery, characterized in that a series of steps for optimizing the above switching period (T) is implemented when a preliminary step for detecting potential failure detects the possibility of insulation failure.
5. In paragraph 4, A method for detecting insulation failure in a storage battery, characterized in that the preliminary step of detecting the above-mentioned potential failure is performed according to an estimate of an insulation resistance value (R CAN ) obtained from a battery management device via a bidirectional data bus such as a CAN bus, and according to a predefined voltage threshold (R threshold ).
6. A device for detecting insulation failure of a storage battery, wherein the device is connected to a storage battery terminal on one side and connected to ground on the other side; and comprises a current limiting resistor ( Rd ), a filtering resistor ( Rm ), and a voltage source ( Ud ) in series, and comprises a filtering capacitor ( Cm ) connected in parallel with the filtering resistor ( Rm ). The above voltage source (U d ) includes a permanent source (U ref ) and another source (U d0 ) that can be actuated by a switch (S 1 ) connected in parallel with the terminals; The above device is designed to measure an insulation resistance value (R i ); The device is designed to detect an insulation failure based on an insulation resistance value (R i ) obtained according to measurements from the current limiting resistor (R d ), the filtering resistor (R m ) and the filtering capacitor (C m ); these measurements are obtained for two individual values of the voltage source (U d ) obtained with a time difference defined by the switching period (T) of the switch (S 1 ), and the device includes means for implementing a series of steps for optimizing the switching period (T), said series of steps, - A step of initializing a time counter (T v ) and a switching period (T) of the switch (S 1 ); and in one loop, in successive increments (t-1, t, t+1) at intervals of a predetermined period (Δ T ), o Measure the voltage across the terminals of the filtering resistor (R m ) above; o Calculate the change in measured voltage between the current increment (t) and the previous increment (t-1); o If the above calculated change is greater than a predetermined threshold, increment the time counter (T v ) by a predetermined period (Δ T ); and o If the above calculated change is lower than the above predetermined threshold, a step of defining the switching period (T) as equal to the value of the time counter (T v ); An insulation failure detection device for a storage battery, characterized by including
7. An automobile comprising an insulation failure detection device for a storage battery according to paragraph 6.

Description

Method for detecting insulation failures in automobiles The present invention relates to a method for detecting insulation failure in an automobile. In the field of automotive battery management, it is particularly important to detect potential insulation failures as quickly as possible. In particular, in electric or hybrid vehicles, the battery consists of a series of cell blocks arranged in series. Therefore, for rapid battery maintenance, it is relatively important to detect insulation failures as quickly as possible and identify the faulty battery block. For this purpose, a method and apparatus for detecting insulation failure based on the measurement of the insulation resistance of a battery are known. As shown in FIG. 1 of the prior art, the battery (11) is shown in the form of a voltage source (110, 111) and an insulation impedance (Zi). A measuring device (10) for measuring insulation resistance (Ri) includes a current limiting resistor (Rd), a filtering resistor (Rm), a filtering capacitor (Cm), and a voltage source (Ud). This measuring device (10) is connected between the lower terminal of the battery (11) and ground, so that it is possible to determine whether there is an insulation failure in the battery and where the insulation failure is located according to the calculated α value as described below. Specifically, it is possible to determine an α value that enables determining the location of insulation failure in a series of cell blocks arranged in series. First, a first voltage (Ud 1 ) is applied to the circuit, and the voltage (Um 1 ) across the terminals of the resistor (Rm) is measured. Next, a second voltage (Ud 2 ) having a value different from the first voltage is applied, and the voltage (Um 2 ) across the terminals of the resistor (Rm) is measured. Next, the insulation resistance (Ri) and the location of the battery's insulation failure (α) are calculated. Since capacitive effects can be ignored, and considering that the total battery voltage (Ubat) is constant across two tests, the following mathematical equation is obtained in steady state. If it is desirable to consider the change in traction battery voltage (Ubat) between two measurements—where Ubat 1 during the first measurement and Ubat 2 during the second measurement—these mathematical expressions are denoted by the following mathematical expressions 3 and 4. Because there is generally a lot of noise in the measurement of Um, mathematical formulas 1-2 or mathematical formulas 3-4 are not used directly. These are generally applied by two recursive least squares (RLS) filters designed to provide stable estimates for each of the two quantities. These filters repeatedly use continuous measurements of voltage (Um) in the process of converging toward the final values of Ri and α. Therefore, these measuring devices periodically provide the monitoring device with an indication of the electrical insulation status of the traction system and allow it to take necessary measures when an insulation failure is observed. However, this implementation of insulation failure detection is not optimized with respect to the period of convergence toward the final values of Ri and α. Document EP3385729B1 describes an analysis method for calculating the optimal switching period of a power circuit. However, this analysis method clearly lacks reliability when considering the variations in parameters inherent in this type of system. To this end, the present invention proposes a method for detecting insulation failure of a capacitor battery, designed to obtain an insulation resistance value from a detection device, and The above detection device is connected to a battery terminal on one side and to ground on the other side, and includes a current limiting resistor, a filtering resistor, and a voltage source in series, and includes a filtering capacitor connected in parallel with the filtering resistor. The above voltage source includes a permanent source and another source that can be operated by a switch connected in parallel with the terminals; The above method detects insulation failure based on insulation resistance values obtained according to measurements from a current-limiting resistor, a filtering resistor, and a filtering capacitor; These measurements are obtained for two individual values of a voltage source obtained with a time difference defined by the switching period of the switch. The above method implements a series of steps to optimize the switching period, and The above series of steps are, - A step of initializing a time counter and the switching period of the switch; and in one loop, at intervals of a predetermined period, in continuous increments, o Measure the voltage across the terminals of the above-mentioned filtering resistor; o Calculate the change in measured voltage between the current increment and the previous increment; o If the above calculated change is greater than a predetermined threshold, increment the time counter by