KR101498758B1 - Apparatus for detecting insulation resistance and diagnostic apparatus thereof - Google Patents

Abstract

There is provided an apparatus for detecting an insulation resistance of a battery pack including a plurality of battery cells. The apparatus includes a first detection unit for detecting a first insulation resistance between an anode and a ground of the battery pack, a second detection unit for detecting a second insulation resistance between the cathode and the ground of the battery pack, A diagnosis unit including a first switch disposed between the first detection units, a second switch disposed between the cathode of the battery pack and the second detection unit, a first auxiliary switch, and a second auxiliary switch, 2 switches to ON / OFF to detect the first and second insulation resistances, and turns on or off at least one of the first, second, first auxiliary and second auxiliary switches to turn the first and second switches And a controller for determining whether or not the failure has occurred.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an insulation resistance detection device,

The present invention relates to a secondary battery, and more particularly, to an apparatus for detecting insulation resistance of a secondary battery and a method and apparatus for diagnosing the detection apparatus.

As the use of portable electric appliances such as video cameras, portable phones, and portable PCs is being activated, the importance of secondary batteries, which are mainly used as driving power sources, is increasing. In particular, the lithium secondary battery has a higher energy density per unit weight and can be rapidly charged as compared with conventional lead-acid batteries and other secondary batteries such as nickel-cadmium batteries, nickel-hydrogen batteries and nickel-zinc batteries. It is actively proceeding.

Unlike conventional primary batteries, which can not be charged, secondary batteries capable of charging and discharging are under active research in the development of advanced fields such as digital cameras, cellular phones, notebook computers, and hybrid vehicles. Examples of the secondary battery include a nickel-cadmium battery, a nickel-metal hydride battery, a nickel-hydrogen battery, and a lithium secondary battery. Among them, the lithium secondary battery has a higher operating voltage than the nickel-cadmium battery or the nickel-metal hydride battery, and has excellent energy density per unit weight.

A secondary battery used in an electric vehicle generally needs to provide a large capacity of 100A to 300A. If deterioration or damage of the secondary battery's battery occurs, the leakage current may increase the power loss or seriously affect the passenger. Therefore, it is important to keep the insulation of the secondary battery in a good state.

Fig. 1 shows an insulation resistance detecting apparatus according to the prior art.

The battery pack 11 includes a plurality of rechargeable battery cells. The insulation resistance detection device (100) detects the insulation resistance of the battery pack (11).

The insulation resistance detection apparatus 100 includes a first detection unit 110 and a second detection unit 120. [ The first detection unit 110 detects a first insulation resistance between the positive electrode of the battery pack 11 and the ground. The second detecting unit 120 detects a second insulation resistance between the negative electrode of the battery pack 11 and the ground.

The first switch SW1 is disposed between the first detecting unit 110 and the anode of the battery pack 11 and the second switch SW2 is disposed between the second detecting unit 120 and the cathode of the battery pack 11. [ do.

When the first switch (SW1) is ON, the first detector 110 detects the first insulation resistance by measuring the V _{_ ADC TOP.} When the second switch (SW2) is ON, the detection unit 120 detects the second insulation resistance by measuring the V _{_ ADC Bottom.}

In order to detect the first and second insulation resistances, the first switch SW1 and the second switch SW2 are frequently turned ON / OFF.

If any one of the first switch SW1 and the second switch SW2 does not operate normally, the resistance value of the insulation resistance can not be detected, and as a result, the normal operation of the battery pack 11 can not be guaranteed.

There is a need for a technique capable of determining whether or not the switches used in the apparatus for detecting the insulation resistance of the secondary battery have failed.

The present invention provides an apparatus and method for detecting an insulation resistance of a battery pack capable of diagnosing a failure.

The present invention also provides a method and apparatus for diagnosing failure of an apparatus for detecting insulation resistance of a battery pack.

In an aspect, an apparatus for detecting an insulation resistance of a battery pack including a plurality of battery cells is provided. The apparatus includes a first detection unit for detecting a first insulation resistance between an anode and a ground of the battery pack, a second detection unit for detecting a second insulation resistance between the cathode and the ground of the battery pack, A diagnosis unit including a first switch disposed between the first detection units, a second switch disposed between the cathode of the battery pack and the second detection unit, a first auxiliary switch, and a second auxiliary switch, 2 switches to ON / OFF to detect the first and second insulation resistances, and turns on or off at least one of the first, second, first auxiliary and second auxiliary switches so that the first and second switches And a controller for determining whether or not the failure has occurred.

The first auxiliary switch may be connected to the positive electrode of the battery pack, and may be connected in parallel with the first switch.

The second auxiliary switch may be connected to the negative electrode of the battery pack, and may be connected in parallel with the second switch.

The controller turns on the first switch and the second auxiliary switch to obtain a first voltage measured by the first detecting unit and turns on the second switch and the first auxiliary switch to measure Acquiring a second voltage, turning on both the first switch and the second switch to obtain a third voltage and a fourth voltage respectively detected by the first and second detecting units, It is possible to detect whether the first switch, the second switch, the first auxiliary switch, and the second auxiliary switch have failed.

In another aspect, a method of diagnosing a failure of an apparatus for detecting an insulation resistance of a battery pack including a plurality of battery cells is provided. The method comprising: detecting a first insulation resistance between an anode and a ground of the battery pack by turning on a first switch; turning on a second switch to detect a second insulation resistance between the cathode of the battery pack and the ground And determining whether the first switch and the second switch are faulty by turning on or off at least one of the first switch, the second switch, the first auxiliary switch, and the second auxiliary switch.

In still another embodiment, the first switch is turned ON to turn on the first detecting unit and the second switch for detecting the first insulation resistance between the positive pole of the battery pack and the ground, and the second insulation resistance between the negative pole of the battery pack and the ground There is provided an apparatus for diagnosing a failure of an insulation resistance detection apparatus including a second detection unit for detecting a failure. The apparatus includes a diagnostic unit including a first auxiliary switch and a second auxiliary switch and a second auxiliary switch connected to the first and second switches by turning on or off at least one of the first, second, And a controller for determining whether the failure has occurred.

It is possible to diagnose whether or not the insulation resistance detecting device of the battery pack is properly operated. It is possible to prevent malfunction due to measurement of erroneous insulation resistance.

Fig. 1 shows an insulation resistance detecting apparatus according to the prior art.
2 is a block diagram illustrating an insulation resistance detection apparatus according to an embodiment of the present invention.
3 is a timing diagram illustrating a method for diagnosing a fault of an insulation resistance detection apparatus according to an embodiment of the present invention.

An electric vehicle refers to a vehicle that includes one or more electric motors as propulsive forces. The energy used to propel the electric vehicle includes an electrical source such as a rechargeable battery and / or a fuel cell. The electric vehicle may be a hybrid electric vehicle that uses a combustion engine as another power source.

The insulation resistance detection device can be used to detect the insulation resistance of a secondary battery used in an electric vehicle. The insulation resistance detection device may be part of a BMS (Battery Management System) or may be part of an ECU (Electrical Control Unit).

The controller may comprise a processor, an application-specific integrated circuit (ASIC), other chipset, logic circuitry and / or a data processing device. When the embodiment is implemented in software, the proposed technique can be implemented as a module (process, function, etc.) that performs the above-described functions. The module is stored in memory and can be executed by the processor. The memory may be internal or external to the processor and may be coupled to the processor by any of a variety of well known means.

2 is a block diagram illustrating an insulation resistance detection apparatus according to an embodiment of the present invention.

The insulation resistance detection device 200 includes a first detection unit 210, a second detection unit 220, a first switch 215, a second switch 225, a diagnosis unit 230 and a controller 240.

The first detection unit 210 detects a first insulation resistance between the positive electrode of the battery pack 11 and the ground. The second detection unit 220 detects a second insulation resistance between the negative electrode of the battery pack 11 and the ground.

A first switch 215 is disposed between the first detecting unit 210 and the anode of the battery pack 11 and a second switch 225 is disposed between the second detecting unit 220 and the cathode of the battery pack 11 do.

When the first switch (SW1) is ON, the first detector 110 detects the first insulation resistance by measuring the V _{_ ADC TOP.} When the second switch (SW2) is ON, the detection unit 120 detects the second insulation resistance by measuring the V _{_ ADC Bottom.}

The diagnostic unit 230 is a module added for diagnosis of the failure of the first switch 215 and the second switch 225. The diagnosis unit 230 includes a first auxiliary switch 231, a first diagnostic resistor 232, a second auxiliary switch 235, and a second diagnostic resistor 236.

The first auxiliary switch 231 is connected to the anode of the battery pack 11 and is connected in parallel with the first switch 215. The first diagnostic resistor 232 is connected in series with the first auxiliary switch 231.

The second auxiliary switch 235 is connected to the cathode of the battery pack 11 and is connected in parallel with the second switch 225. The second diagnostic resistor 236 is connected in series with the second auxiliary switch 235.

The resistance value of the first diagnostic resistor 232 and the second diagnostic resistor 236 may be 500 k ohms.

The controller 240 detects the first and second insulation resistances and controls at least one of the first switch 215, the second switch 225, the first auxiliary switch 231 and the second auxiliary switch 235 Diagnose the failure. The controller 240 turns on / off the first switch 215, the second switch 225, the first auxiliary switch 231, and the second auxiliary switch 235.

3 is a timing diagram illustrating a method for diagnosing a fault of an insulation resistance detection apparatus according to an embodiment of the present invention.

The insulation resistance detection apparatus 200 can perform two steps of the insulation resistance measurement step S310 and the failure diagnosis step S320. The two steps need not necessarily be continuously performed, and the insulation resistance detection device 200 may perform the insulation resistance measurement step S310 after performing the failure diagnosis step S320 first. The insulation resistance detection device 200 may perform the failure diagnosis step S320 after performing the insulation resistance measurement step S310 several times.

The insulation resistance measuring step S310 includes a step (1) in which the first switch 215 is turned on and a step (2) in which the second switch 215 is turned on. Through the steps (1) and (2), the first and second insulation resistances are measured.

The fault diagnosis step S320 includes steps (3) to (5). In step (3), the first switch 215 and the second auxiliary switch 235 are turned ON. In step (4), the second switch 225 and the first auxiliary switch 231 are turned ON. In step (5), the first switch 215 and the second switch 225 are turned ON.

There is no restriction on the order of steps (1) and (2) of the insulation resistance measuring step S310 and steps (3) to (5) of the failure diagnosis step S320. For example, it is possible to proceed in the order of (2) -> (1) in the insulation resistance measuring step S310, and in the fault diagnosis step S320, the order of (5) -> (4) -> Lt; / RTI >

The sections in which the ON state continues in the (1) and (2) steps of the insulation resistance measuring step S310 are different from each other in the sections in which the ON state continues in the steps (3) to (5) . For example, steps (1) and (2) of the insulation resistance measuring step S310 continue to be ON for 500 ms, while steps (3) to (5) of the fault diagnosis step S320 are ON for 300 ms to 400 ms Can be sustained.

The insulation resistance measurement step (S310) (1) (2 ) of the stage and the diagnosis step (S320) (3) ~ ( 5) V is measured in step _{ADC _ Top} and V _{ADC _} the _Bottom-based breakdown of the switches Whether or not it can be determined as shown in the following table.

switch Failure type Explanation The first switch OPEN 1 and 3, when the V _{_ ADC Top} is the same, and (5) V _{_ ADC} is 0V _Top SHORT (2) V _{ADC _} when _Top is not a 0V The second switch OPEN 2 and 4, when the V _{_ ADC Bottom} a V of the same, and (5) _{Bottom _ ADC} is 5V SHORT (1) V _{ADC _} when _Bottom is not a 5V The first auxiliary switch OPEN 2 and 4 of the V _{_ ADC Bottom} is the same, and (5) V _{_ ADC Bottom} when not in the 5V SHORT The second auxiliary switch OPEN 1 and 3 of the V _{_ ADC Top} is the same, and when it is not _{_ Top} V _ADC is 0V (5) SHORT

In the fault type, 'OPEN' means that the switch is still open and 'SHORT' means that the switch is still closed.

It can be seen from Table 1 that not only failure of the first switch 215 and the second switch 225 but also failure of the first auxiliary switch 231 and the second auxiliary switch 235 can be discriminated have.

Claims (12)

An apparatus for detecting an insulation resistance of a battery pack including a plurality of battery cells,
A first detecting unit for detecting a first insulation resistance between the positive electrode of the battery pack and the ground;
A second detecting unit for detecting a second insulation resistance between the negative electrode of the battery pack and the ground;
A first switch disposed between the positive electrode of the battery pack and the first detection unit;
A second switch disposed between the cathode of the battery pack and the second detection unit;
A diagnostic unit including a first auxiliary switch and a second auxiliary switch; And
The first and second switches are turned ON / OFF to detect the first and second insulation resistances, and at least any one of the first, second, first auxiliary and second auxiliary switches is turned ON Or OFF to determine whether the first and second switches are faulty or not. The method according to claim 1,
Wherein the first auxiliary switch is connected to the anode of the battery pack and is connected in parallel with the first switch. 3. The method of claim 2,
Wherein the second auxiliary switch is connected to the negative electrode of the battery pack and is connected in parallel with the second switch. The method of claim 3,
The controller turns on the first switch and the second auxiliary switch to obtain a first voltage measured by the first detecting unit and turns on the second switch and the first auxiliary switch to measure Acquiring a second voltage, turning on both the first switch and the second switch to obtain a third voltage and a fourth voltage respectively detected by the first and second detecting units,
And detects whether the first switch, the second switch, the first auxiliary switch, and the second auxiliary switch are faulty based on the first to fourth voltages. A method for diagnosing a failure of an apparatus for detecting an insulation resistance of a battery pack including a plurality of battery cells,
Detecting a first insulation resistance between an anode and a ground of the battery pack by turning on a first switch;
Turning on the second switch to detect a second insulation resistance between the cathode of the battery pack and the ground;
Determining whether the first switch and the second switch are faulty by turning on or off at least any one of the first switch, the second switch, the first auxiliary switch, and the second auxiliary switch for a predetermined time, Methods of inclusion. 6. The method of claim 5,
Wherein the first switch is disposed between the anode of the battery pack and the first detecting portion, and the second switch is disposed between the cathode of the battery pack and the second detecting portion. The method according to claim 6,
Wherein the first auxiliary switch is connected to the anode of the battery pack and is connected in parallel with the first switch. 8. The method of claim 7,
Wherein the second auxiliary switch is connected to the cathode of the battery pack, and is connected in parallel with the second switch. 9. The method of claim 8,
Wherein the step of determining whether the first switch and the second switch are faulty
Turning on the first switch and the second auxiliary switch to obtain a first voltage measured by the first detecting unit;
Turning on the second switch and the first auxiliary switch to obtain a second voltage measured by the second detector;
Turning on both the first switch and the second switch to obtain a third voltage and a fourth voltage respectively detected by the first and second detecting units;
And detecting whether the first switch, the second switch, the first auxiliary switch, and the second auxiliary switch are faulty based on the first to fourth voltages. A first detecting section for detecting a first insulation resistance between an anode and a ground of the battery pack by turning on a first switch and a second detecting section for detecting a second insulation resistance between a cathode of the battery pack and the ground, The apparatus for diagnosing a failure of an insulation resistance detection apparatus comprising:
A diagnostic unit including a first auxiliary switch and a second auxiliary switch; And
And a controller for determining whether the first and second switches are faulty by turning on or off at least any one of the first, second, first auxiliary and second auxiliary switches for a predetermined time. 11. The method of claim 10,
The first auxiliary switch is connected to the positive electrode of the battery pack and is connected in parallel with the first switch,
Wherein the second auxiliary switch is connected to the negative electrode of the battery pack and is connected in parallel with the second switch. 12. The method of claim 11,
The controller turns on the first switch and the second auxiliary switch to obtain a first voltage measured by the first detecting unit and turns on the second switch and the first auxiliary switch to measure Acquiring a second voltage, turning on both the first switch and the second switch to obtain a third voltage and a fourth voltage respectively detected by the first and second detecting units,
And detects whether the first switch, the second switch, the first auxiliary switch, and the second auxiliary switch are faulty based on the first to fourth voltages.

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