Battery pack and device for eliminating Y capacitor influence of battery pack

Abstract

The utility model discloses a battery pack and a device for eliminating the influence of a Y capacitor of the battery pack, the device comprises a resistor, the resistor is arranged between an electric box shell of the battery pack and a low-voltage circuit, the resistor and the Y capacitor form an RC discharge circuit, the voltage of the low-voltage circuit can be pulled to be close to 0V through discharge, components in the low-voltage circuit are better protected, and the service life of the battery pack is prolonged. The problem that the low-voltage circuit is damaged due to the fact that the voltage between the electric box shell and the low-voltage circuit exceeds a design value during the withstand voltage test is avoided.

Description

Technical Field

[0001] This utility model belongs to the field of rail transit power testing technology, and in particular relates to a battery pack and a device for eliminating the influence of the Y capacitor in the battery pack. Background Technology

[0002] To achieve electrification, the power batteries used in rail transit power systems must meet relevant rail transit standards for withstand voltage. Therefore, the design of rail transit battery packs must comply with relevant rail transit standards (AC5600V / 1min or DC7918V / 1min). Furthermore, to ensure that each battery pack meets withstand voltage test requirements, a withstand voltage test is required for each battery pack during routine factory testing. Because of the presence of the Y capacitor in the battery pack, the withstand voltage test can damage the low-voltage circuitry.

[0003] like Figure 1 As shown, during the withstand voltage test, the two probes 41 / 42 of the withstand voltage tester 4 are connected to the high-voltage conductor 2 and the low-voltage circuit 3 respectively. Since the high-voltage power battery system needs to withstand higher voltages between the power line and the battery box 1 or between the power line and the low-voltage circuit 3, when the battery cell group 2 is placed flat in the battery box 1, a distributed capacitance C1 (i.e., Y capacitor) will be formed between the battery cell group 2 and the battery box 1. Its capacitance value is usually between 10nF and 15nF and cannot be avoided.

[0004] Due to the presence of the Y capacitor, only DC withstand voltage testing can be selected. However, when testing high voltage against low voltage, the enclosure is effectively suspended. Because of the Y capacitor, the withstand voltage is transferred to the enclosure through the Y capacitor. Therefore, the voltage of the enclosure relative to the high voltage is close to 0, and the voltage between the enclosure and the low voltage circuit is close to the test voltage (e.g., DC 8000V, assuming the test voltage is 8000V). The withstand voltage between the enclosure and the low voltage circuit is DC 500V. This results in the voltage between the enclosure and the low voltage circuit (close to the test voltage DC 8000V) far exceeding the designed withstand voltage value DC 500V when testing high voltage against low voltage. This makes the low voltage circuit section prone to damage during the withstand voltage test. Utility Model Content

[0005] The purpose of this invention is to provide a battery pack and a device for eliminating the influence of the Y capacitor in the battery pack, so as to solve the problem that the voltage between the battery box shell and the low-voltage circuit during the withstand voltage test is far greater than the designed withstand voltage value due to the presence of the Y capacitor, which in turn leads to the easy damage of the low-voltage circuit.

[0006] This utility model solves the above-mentioned technical problems through the following technical solution: a device for eliminating the influence of Y capacitance in a battery pack, comprising a resistor, wherein the resistor is disposed between the battery pack housing and the low-voltage circuit.

[0007] Further, the equivalent capacitance value of the Y capacitor is 10nF-15nF.

[0008] Further, the voltage resistance value of the resistor is greater than or equal to 500V.

[0009] Further, the voltage resistance value of the resistor is 1000V.

[0010] Further, the resistance value of the resistor is 100Ω-10KΩ.

[0011] Further, the resistance value of the resistor is 1KΩ.

[0012] Based on the same concept, the utility model provides a kind of battery pack, the battery pack includes electric box shell, and the electric core group, low voltage circuit and the device for eliminating the influence of battery pack Y capacitor in the electric box shell are arranged.

[0013] Further, the electric core group includes a plurality of electric core monomers, and the plurality of electric core monomers are connected in series or parallel or series-parallel.

[0014] Beneficial effects

[0015] Compared with prior art, the utility model has the advantages that:

[0016] The utility model sets up resistance between electric box shell and low voltage circuit, and resistance and Y capacitor form RC discharge circuit, and the voltage of low voltage circuit can be pulled to close 0V by discharging, so that the components in low voltage circuit are better protected, and the problem that the voltage between electric box shell and low voltage circuit exceeds design value during voltage resistance test, resulting in low voltage circuit damage, is avoided.

[0017] The device for eliminating the influence of battery pack Y capacitor provided by the utility model not only does not affect normal use, but also eliminates the influence of Y capacitor during voltage resistance test (high voltage to low voltage), so that the voltage between electric box shell and low voltage circuit is not greater than design voltage resistance value, and the normal of low voltage circuit part is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical scheme of the utility model, the following will be briefly introduced the drawings needed to be used in embodiment description, obviously, the drawings in the following description are only one embodiment of the utility model, and other drawings can be obtained according to these drawings without creative labor for ordinary skilled in the art.

[0019] Figure 1 It is the battery pack voltage resistance test principle diagram in the background technology of the utility model;

[0020] Figure 2It is an equivalent circuit schematic diagram in the process of high-voltage to low-voltage withstand voltage test in the embodiment of the utility model.

[0021] Figure 3 It is an internal structure schematic diagram of the battery pack in the embodiment of the utility model.

[0022] Mark explanation: 1 - electric box shell, 2 - electric core group or high-voltage conductor, 3 - low-voltage circuit, 4 - withstand voltage tester, 41 - first probe, 42 - second probe, 5 - insulating glue. DETAILED DESCRIPTION

[0023] The technical scheme in the utility model is clearly and completely described below in combination with the drawings in the embodiment of the utility model, and obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor belong to the protection scope of the utility model.

[0024] As Figure 2 and Figure 3 Indicated, a kind of device for eliminating battery pack Y capacitance influence provided in the embodiment of the utility model includes resistance R1, resistance R1 is located between the electric box shell 1 of battery pack and low-voltage circuit 3.

[0025] Electric core group 2 in battery pack is placed in electric box shell 1, and forms a distributed capacitance C1 (i.e. Y capacitance) between electric box shell 1 and the A face and B face of electric core group 2 (i.e. Figure 3 The equivalent capacitance value of Y capacitance C1 is 10nF~15nF. Increase a resistance R1 between electric box shell 1 and low-voltage circuit 3 (generally connected at 24V power supply ground), Y capacitance C1 and resistance R1 are connected in series to form an RC discharge loop. As Figure 2 Indicated, before high-voltage to low-voltage withstand voltage test, the first probe 41 of withstand voltage tester 4 is connected to the positive power supply or negative power supply (i.e. high-voltage conductor) of electric core group 2, and the second probe 42 of withstand voltage tester 4 is connected to the low-voltage positive power supply at the input end of low-voltage circuit 3. Set test voltage as DC8000V, when high-voltage to low-voltage withstand voltage test, test voltage is added between electric core group 2 and low-voltage circuit 3, when Y capacitance C1 is full of electricity, the equivalent internal resistance of Y capacitance C1 is close to infinity, at this time, the current flowing through Y capacitance C1 and resistance R1 is close to 0, the voltage on resistance R1 is close to 0, i.e. it is guaranteed that the voltage between electric box shell 1 (F point) and low-voltage circuit 3 part (G point) does not exceed the designed withstand voltage value (for example 500V), to ensure that low-voltage circuit 3 part will not be damaged due to withstand voltage test.

[0026] In the specific embodiment of the utility model, the voltage resistance of the resistor R1 is greater than or equal to 500V, and in order to have a margin, the voltage resistance of the resistor R1 in the embodiment is selected as 1000V, that is, a resistor with a voltage resistance of 1000V is selected as R1.

[0027] The resistance of the resistor R1 depends on the rate of the test voltage rising in the voltage resistance test process, and generally the rising rate of the test voltage is controlled within 10s, the greater the resistance of the resistor R1, the smaller the influence on the high voltage resistance power battery system, but the effect is poorer, on the contrary, the smaller the resistance of the resistor R1, the greater the influence on the high voltage resistance power battery system, but the effect is better. In the specific embodiment of the utility model, the resistance of the resistor R1 is selected as 100Ω-10KΩ, and preferably 1KΩ.

[0028] As shown in Figure 3 The utility model discloses a kind of battery pack, including electric box shell 1, and the device for eliminating battery pack Y capacitor influence in the electric box shell 1 of the electric core group 2, low voltage circuit 3 and the embodiment of the application in the electric core group 2.

[0029] In the specific embodiment of the utility model, the electric core group 2 is constituted by a plurality of electric core monomers in series, or constituted by a plurality of electric core monomers in parallel, or constituted by a plurality of electric core monomers in series and in parallel. Insulating glue 5 is laid between electric core group 2 and electric box shell 1.

[0030] The above disclosed is only the specific embodiment of the utility model, but the protection scope of the utility model is not limited to this, any skilled person in the art can easily think of change or modification within the technical range disclosed by the utility model, and it should be covered in the protection scope of the utility model.

Claims

1. An apparatus for eliminating the effect of battery pack Y capacitance, characterized in that, The device comprises a resistor arranged between an electric box shell of the battery pack and a low-voltage circuit.

2. The apparatus for eliminating the effect of the battery pack Y capacitance according to claim 1, characterized by, An equivalent capacitance value of the Y capacitor is 10nF-15nF.

3. The apparatus for eliminating the effect of battery pack Y capacitance according to claim 1, wherein, The resistor has a voltage resistance value greater than or equal to 500V.

4. The apparatus for eliminating the effect of battery pack Y capacitance according to claim 1, wherein, The resistor has a voltage resistance value of 1000V.

5. The apparatus for eliminating the effect of battery pack Y capacitance of claim 1, wherein, The resistor has a resistance value of 100Ω-10KΩ.

6. The apparatus for eliminating the effect of battery pack Y capacitance of claim 1, wherein, The resistor has a resistance value of 1KΩ.

7. A battery pack, characterized by, The battery pack comprises an electric box shell, a battery cell group arranged in the electric box shell, a low-voltage circuit, and the device for eliminating the influence of the Y capacitor of the battery pack according to any one of claims 1-6.

8. The battery pack of claim 7, wherein, The battery cell group comprises a plurality of battery cell monomers connected in series, in parallel, or in series-parallel.

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