Insulation detection circuit suitable for high and low voltage energy storage equipment

Abstract

The utility model discloses an insulation detection circuit suitable for high and low voltage energy storage equipment, and belongs to the technical field of insulation detection. The device comprises a power supply module, a floor drain resistance detection module and a voltage sampling module, the power supply module is connected to two ends of the floor drain resistance detection module to form an electric loop, and the voltage sampling module is connected with the floor drain resistance detection module to perform voltage sampling on an insulation resistor in the floor drain resistance detection module; the voltage sampling module comprises a sampling circuit, a first divider resistor Ra sum and a second divider resistor Rb sum, the first divider resistor Ra sum comprises a plurality of divider resistors connected in series, and the second divider resistor Rb sum comprises a plurality of divider resistors connected in parallel. According to the utility model, a proper voltage division ratio is given according to different voltage grades, so that the insulation detection circuit can ensure full utilization of the measuring range on different voltage platforms.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of insulation detection, specifically, relate to a kind of insulation detection circuit suitable for high-low voltage energy storage equipment. BACKGROUND

[0002] Energy storage equipment is a complex electrical system, and the electrical system thereof can have a low-voltage part and a high-voltage part. The low-voltage part is powered by low-voltage electricity within the device, such as related electronic equipment and logic control circuit, which generally uses 12V / 24V power supply. The negative pole of the low-voltage power supply is directly connected to the system shell. The high-voltage part is the inverter input and output of the energy storage equipment and the battery. There is no direct electrical connection between the high-voltage electrical system of the energy storage equipment and the chassis. The insulation performance between the high-voltage electrical system and the vehicle chassis will be reduced due to the aging of the cable insulation medium of the direct-current high-voltage system or the influence of factors such as humid environment. The positive or negative lead of the power supply will form a leakage loop between the insulation layer and the chassis, causing the device shell to have high voltage. This not only affects the normal operation of the low-voltage electrical and controller, but also endangers the personal safety of the user.

[0003] The commonly used insulation detection architecture currently mainly refers to the parallel resistance method of GB / T18384.1, and the circuit architecture is as shown in Figure 1 The disadvantage of this method is that the voltage of V1 has a great influence on the measurement resolution of the insulation resistance. In the case of fixed Ra and Rb, the higher the voltage of V1, the higher the insulation resistance resolution, and the lower the voltage of V1, the lower the insulation resistance resolution. Since the voltage platform of the energy storage equipment spans a large range, even more than 1000V, the insulation resistance is calculated by fixed resistance voltage division collection. In different working voltage platforms, it is difficult to ensure the accuracy of insulation resistance calculation with a single voltage division ratio design. Moreover, the insulation detection of this architecture for systems with working voltage higher than 800V will be challenging for the hardware design and device selection of the insulation detection device itself, and even difficult to implement. In addition, the insulation detection of this architecture requires three voltage sampling (two voltage division sampling and one total voltage sampling), which occupies more ADC resources and is not conducive to cost reduction. SUMMARY

[0004] 1. Technical problem to be solved by the utility model

[0005] In view of the problems existing in the prior art mentioned in the background, the utility model provides an insulation detection circuit suitable for high-low voltage energy storage equipment to solve the above problems.

[0006] 2. Technical solution

[0007] To achieve the above purpose, the technical solution provided by the utility model is as follows:

[0008] The utility model provides an insulation detection circuit suitable for high and low voltage energy storage equipment, including power module, ground leakage resistance detection module and voltage sampling module, wherein power module is connected in ground leakage resistance detection module both ends and forms the electric circuit, voltage sampling module is connected with ground leakage resistance detection module, and the insulation resistance in ground leakage resistance detection module carries out voltage sampling, voltage sampling module includes sampling circuit, first voltage division resistance Ra 总 And second voltage division resistance Rb 总 , first voltage division resistance Ra 总 Include a plurality of series connection voltage division resistances, second voltage division resistance Rb 总 Include a plurality of parallel connection voltage division resistances.

[0009] As the utility model further improves, second voltage division resistance Rb 总 Include resistance Rb1, resistance Rb2 and resistance Rb3, resistance Rb1 is connected in parallel with resistance Rb2 through switch SW3, and is connected in parallel with resistance Rb3 through switch SW4.

[0010] As the utility model further improves, first voltage division resistance Ra 总 And second voltage division resistance Rb 总 Series connection.

[0011] As the utility model further improves, first voltage division resistance Ra 总 Among them, resistance Ra1 one end is connected with power module anode, and the other end is connected with resistance Ra2 and switch SW1 respectively, the other end of resistance Ra2 is connected with switch SW1, resistance Ra3 and switch SW2 simultaneously, the other end of resistance Ra3 is connected with switch SW2 and resistance Ra4 simultaneously, the other end of resistance Ra4 is connected with sampling circuit and second voltage division resistance Rb 总 Connection.

[0012] As the utility model further improves, second voltage division resistance Rb 总 Among them, resistance Rb1 one end is connected to resistance Ra4, and the other end is connected with power module cathode, and is connected with switch SW3 simultaneously, the other end of switch SW3 is connected with resistance Rb2 and switch SW4, the other end of resistance Rb2 is connected with resistance Ra4, the other end of switch SW4 is connected with resistance Rb3, and the other end of resistance Rb3 is connected with resistance Ra4.

[0013] As a further improvement of the utility model, the ground leakage resistance detection module comprises insulation resistances Rx and Ry, one end of the insulation resistance Rx is connected with the positive pole of the power module, the other end is connected with the insulation resistance Ry at the same time, and is connected between the resistances Ra2 and Ra3, and the connection end is grounded at the same time; the other end of the insulation resistance Ry is connected to the negative pole of the power module.

[0014] As a further improvement of the utility model, the switches SW1, SW2, SW3 and SW4 are connected with the MCU controller, and the MCU controller is used for controlling the opening and closing of the switches SW1, SW2, SW3 and SW4.

[0015] As a further improvement of the utility model, the sampling circuit is an ADC sampling circuit.

[0016] 3. Beneficial effects

[0017] Compared with the prior art, the technical scheme has the following remarkable effects:

[0018] The insulation detection circuit suitable for high-low voltage energy storage equipment is provided, two groups of voltage dividing resistors are arranged, in particular, the second voltage dividing resistor Rb 总 is arranged, a plurality of parallelly connected resistors are arranged in the second voltage dividing resistor Rb 总 , the plurality of parallelly connected resistors are connected through a switch, the switch is controlled by the MCU controller, thereby the resistance value of the second voltage dividing resistor Rb 总 is set, a suitable voltage dividing ratio is given according to different voltage grades, the insulation detection circuit can fully utilize the range under different voltage platforms, and the ADC sampling in the insulation detection circuit only needs to sample one total voltage and one voltage division, so that the insulation resistance value can be obtained, the occupation of the ADC resource is reduced, and the cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a circuit structure diagram of the insulation detection architecture in the prior art;

[0020] Figure 2 It is a circuit structure diagram of the insulation detection architecture in the prior art; DETAILED DESCRIPTION

[0021] In order to make the above objectives, characteristics and advantages of the utility model more apparent and easily understood, the specific embodiments of the utility model are described in detail below in conjunction with the drawings. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the utility model, therefore the utility model is not limited by the specific embodiments disclosed below.

[0022] In the description of the utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0023] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the utility model, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0024] In the utility model, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0025] In the present application, unless otherwise specifically stated and limited, a first feature is "on" or "under" a second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature is "on", "above" and "on the surface" of the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature is "under", "below" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0026] It should be noted that when an element is referred to as "fixed to" or "provided on" another element, it can be directly on another element or there can be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and are not the only embodiment.

[0027] Embodiment

[0028] In combination Figure 2 , the insulation detection circuit of the high-low voltage energy storage device of the embodiment comprises a power supply module, a ground leakage resistance detection module and a voltage sampling module, wherein the power supply module is connected across the ground leakage resistance detection module to form an electric circuit, the voltage sampling module is connected with the ground leakage resistance detection module, and the insulation resistance in the ground leakage resistance detection module is voltage sampled; the voltage sampling module comprises a sampling circuit, a first voltage dividing resistor Ra 总 and a second voltage dividing resistor Rb 总 , the first voltage dividing resistor Ra 总 comprises a plurality of series-connected voltage dividing resistors, and the second voltage dividing resistor Rb 总 comprises a plurality of parallel-connected voltage dividing resistors.

[0029] Specifically, in the present embodiment, the first voltage dividing resistor Ra 总 comprises resistors Ra1, Ra2, Ra3 and Ra4, the resistors Ra1 and Ra4 have the same resistance value, the resistors Ra2 and Ra3 have the same resistance value, and the resistance value of the resistors Ra2 and Ra3 is twice that of the resistors Ra1 and Ra4. The second voltage dividing resistor Rb 总 comprises resistors Rb1, Rb2 and Rb3, the resistor Rb1 is connected in parallel with the resistor Rb2 through a switch SW3, and is connected in parallel with the resistor Rb3 through a switch SW4.

[0030] The application relates to an insulation detection circuit of a high-low voltage energy storage device, and the specific connection structure is as follows: a positive pole of a power module is connected to one end of a resistor Ra1, the other end of the resistor Ra1 is connected to a resistor Ra2 and a switch SW1, the other end of the resistor Ra2 is connected to the switch SW1, a resistor Ra3 and a switch SW2 at the same time; the other end of the resistor Ra3 is connected to the switch SW2 and a resistor Ra4 at the same time, the other end of the resistor Ra4 is connected to a sampling circuit and one end of a resistor Rb1 at the same time; the other end of the resistor Rb1 is connected to a negative pole of the power module and the switch SW3 at the same time, the other end of the switch SW3 is connected to a resistor Rb2 and a switch SW4; the other end of the resistor Rb2 is connected to the resistor Ra4; the other end of the switch SW4 is connected to a resistor Rb3, and the other end of the resistor Rb3 is connected to the resistor Ra4.

[0031] In the embodiment, the ground leakage resistance detection module comprises insulation resistors Rx and Ry, one end of the insulation resistor Rx is connected to a positive pole of a power module, the other end of the insulation resistor Rx is connected to an insulation resistor Ry and connected to a resistor Ra2 and a resistor Ra3 at the same time, and the connection end is connected to the ground at the same time; the other end of the insulation resistor Ry is connected to a negative pole of the power module.

[0032] In the embodiment, the switches SW1, SW2, SW3 and SW4 are connected to an MCU controller, and the MCU controller is used for controlling the opening and closing of the switches SW1, SW2, SW3 and SW4. The sampling circuit in the embodiment is an ADC sampling circuit.

[0033] In the embodiment, Rx and Ry are respectively the ground leakage resistance values of the positive and negative bus lines, Ra 总 , Rb 总 are the voltage division resistors of the ADC sampling, and the value of Rb 总 can be controlled by the on-off of the switches SW3 and SW4, the MCU controller can give a proper voltage division ratio according to different voltage grades, so that the insulation detection circuit in the embodiment can be used in different voltage platforms and the full use of the range can be ensured. The specific resistance derivation process is as follows:

[0034] Supposing that the total voltage between the positive and negative poles of the power module (namely between P+ and P-) is u, the switches SW1 and SW2 are disconnected first, and the voltage value V1 of the Rx and Ry is measured, if there is no leakage, then

[0035]

[0036] If , the negative pole leaks; if , the positive pole leaks.

[0037] When the negative electrode leaks, first close the switch SW1, the sampling voltage at this time is V2, and the voltage u1 between the two ends of the resistor Ry when the switch SW1 is opened and the voltage u2 between the two ends of the resistor Ry when the switch SW1 is closed are measured. At this time, the following can be obtained

[0038]

[0039]

[0040] The voltage ux between the two ends of the resistor Rx is

[0041]

[0042] Thus, the following can be obtained

[0043] Similarly, when the positive electrode leaks, close the switch SW2, and calculate Ry by the same derivation process.

[0044] The above describes the utility model and its embodiments in a schematic manner, and the description is not restrictive, and the embodiments shown in the drawings are only one of the embodiments of the utility model, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired thereby, without departing from the creative purpose of the utility model, similar structural modes and embodiments are not designed creatively, and all should belong to the protection scope of the utility model.

Claims

1. An insulation detection circuit for high and low voltage energy storage devices, characterized by, The application relates to a leakage resistance detection device, which comprises a power module, a ground leakage resistance detection module and a voltage sampling module, wherein the power module is connected across the ground leakage resistance detection module to form an electric circuit, the voltage sampling module is connected with the ground leakage resistance detection module, and the insulation resistance in the ground leakage resistance detection module is subjected to voltage sampling; the voltage sampling module comprises a sampling circuit, a first voltage dividing resistor Ra 总 and a second voltage dividing resistor Rb 总 , the first voltage dividing resistor Ra 总 comprises a plurality of series-connected voltage dividing resistors, and the second voltage dividing resistor Rb 总 comprises a plurality of parallel-connected voltage dividing resistors.

2. The insulation detection circuit according to claim 1, wherein The first voltage dividing resistor Ra 总 The first voltage dividing resistor Ra The first voltage dividing resistor Ra 3. The insulation detection circuit according to claim 1, wherein The second voltage dividing resistor Rb 总 The second voltage dividing resistor Rb The second voltage dividing resistor Rb 4. The insulation detection circuit according to claim 1, wherein The first voltage dividing resistor Ra 总 and the second voltage dividing resistor Rb 总 are connected in series.

5. The insulation detection circuit according to claim 1, wherein The first voltage dividing resistor Ra 总 In the middle, the resistor Ra1 one end and the positive pole of power module, the other end is connected with the resistor Ra2 and switch SW1 respectively, the other end of the resistor Ra2 is connected with switch SW1, resistor Ra3 and switch SW2 at the same time; the other end of the resistor Ra3 is connected with switch SW2 at the same time and connected with the resistor Ra4, the other end of the resistor Ra4 is connected with the sampling circuit at the same time, and connected with the second voltage dividing resistor Rb 总 .

6. The insulation detection circuit according to claim 5, wherein The second voltage dividing resistor Rb 总 In the embodiment, one end of the resistor Rb1 is connected to the resistor Ra4, the other end is connected to the negative pole of the power module, and is also connected to the switch SW3. The other end of the switch SW3 is connected to the resistor Rb2 and the switch SW4. The other end of the resistor Rb2 is connected to the resistor Ra4. The other end of the switch SW4 is connected to the resistor Rb3, and the other end of the resistor Rb3 is connected to the resistor Ra4.

7. The insulation detection circuit according to claim 6, wherein The ground leakage resistance detection module comprises insulation resistances Rx and Ry, one end of the insulation resistance Rx is connected with the positive pole of the power module, the other end of the insulation resistance Rx is connected with the insulation resistance Ry and connected between the resistance Ra2 and the resistance Ra3, and the connecting end is grounded; the other end of the insulation resistance Ry is connected with the negative pole of the power module.

8. The insulation detection circuit according to claim 7, wherein the high-voltage storage device is a high-voltage capacitor, and the low-voltage storage device is a low-voltage capacitor. The switches SW1, SW2, SW3 and SW4 are connected with the MCU controller, and the MCU controller is used for controlling the opening and closing of the switches SW1, SW2, SW3 and SW4.

9. The insulation detection circuit for high and low voltage energy storage device according to any one of claims 1-8, characterized in that, The sampling circuit is an ADC sampling circuit.

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