CN111398836A - An integrated power battery high voltage detection system and its insulation verification method - Google Patents

Abstract

The invention relates to the technical field of battery detection, in particular to an integrated power battery high-voltage detection system and an insulation verification method thereof. It includes a single-chip microcomputer module, a total voltage acquisition module, an insulation detection module, a communication module, and a power supply module, as well as a first current detection module and a second current detection module. The first current detection module is connected between the positive input end and the output end of the battery, The second current detection module is connected between the negative input terminal and the output terminal of the battery. The current signal output terminals of the first current detection module and the second current detection module are both electrically connected to the current signal input terminal of the single-chip module. The current sensors used by the two current detection modules are different types of current sensors. A current detection is set in the positive input and output of the battery and the negative input and output respectively, which increases the fault tolerance rate of the current detection, ensures the validity of the current detection data, and improves the safety of the power battery.

Description

An integrated power battery high voltage detection system and its insulation verification method

technical field

The invention relates to the technical field of battery detection, in particular to an integrated power battery high-voltage detection system and an insulation verification method thereof.

Background technique

The power battery high voltage detection system is a system used to detect battery safety-related parameters in electric vehicles. It usually needs to detect the current, voltage, resistance and other data of the battery. In the detection system, the accuracy and reliability of current signal detection are very important, especially for SOC and SOE algorithms, the current signal is a very important value.

At present, common power battery systems usually use a single current sensor solution for current detection, and most of them are shunt current sensors. Its only one current detection is easy to fail, resulting in the failure of current detection, thus affecting the safety of the power battery. At the same time, the insulation detection lacks verification, and its detection value sometimes cannot guarantee the accuracy, thus affecting the safety of the power battery.

Thirdly, in the prior art solution, a temperature sensitive resistor is used to detect the high-voltage precision resistance temperature, and its detection value is only a single temperature point on the high-voltage precision resistance, and the temperature cannot represent the entire high-voltage precision resistance temperature. The temperature compensation of the shunt scheme will lead to low accuracy in high current detection. In the prior art solution, the total voltage sampling and current sampling functions are separated into different chips or different controllers, resulting in asynchronous data collection frequency, resulting in inaccurate calculation of the ampere-hour integration and power integration of the relevant controllers, thereby reducing the remaining power. , remaining mileage, vehicle energy consumption and other parameters calculation accuracy, affecting the user's use.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an integrated power battery high voltage detection system and an insulation verification method thereof with high fault tolerance rate and high safety performance, aiming at the defects of the prior art.

The present invention is an integrated power battery high-voltage detection system, the technical scheme of which is that it comprises a single-chip microcomputer module, a total voltage acquisition module, an insulation detection module, a communication module, a power supply module, and further comprises a first current detection module and a second current detection module, The first current detection module is connected between the positive input terminal and the output terminal of the battery, the second current detection module is connected between the negative input terminal and the output terminal of the battery, the first current detection module and the second current detection module The current signal output end of the module is electrically connected with the current signal input end of the single-chip module, the voltage signal output end of the total voltage acquisition module is electrically connected with the voltage signal input end of the single-chip module, and the voltage signal output end of the insulation detection module is electrically connected The resistance signal output terminal of the single-chip microcomputer module is electrically connected to the resistance signal input terminal of the single-chip microcomputer module, the communication module is electrically connected to the communication interface of the single-chip microcomputer module, and the power supply module is electrically connected to the power supply signal input terminal of the single-chip microcomputer module;

The current sensors used by the current detection module and the second current detection module are different types of current sensors.

Preferably, the first current detection module is a shunt current sensor, a temperature sensor is provided at the center above the high-voltage precision resistor R713 of the shunt current sensor, and a temperature sensor is provided between the temperature sensor and the surface of the high-voltage precision resistor R713. There are gaps.

More preferably, it also includes a comparison amplifier U605A, the first current detection module is a shunt current sensor, the second current detection module is a Hall sensor, and the shunt current sensor and the Hall sensor are connected in series with the positive and negative poles of the battery. In between, the high-voltage precision resistor R713 of the shunt current sensor is connected to one end of the positive electrode of the battery and is connected to the inverting input terminal of the comparator amplifier U605A, and the high-voltage precision resistor R713 is connected to one end of the Hall sensor and the non-inverting input terminal of the comparator amplifier U605A. connection, the output end of the comparison amplifier U605A is connected with the current signal input end of the single-chip microcomputer module.

Preferably, the total voltage acquisition module includes a plurality of voltage acquisition circuits arranged in parallel, the voltage acquisition circuit includes resistors R714-R717, the resistor R714 and the resistor R715 are connected in series between the positive electrode of the battery and the ground, and the resistor R716 is connected to the ground. The resistor R717 is connected in series between the positive electrode of the battery and the ground. The voltage between the resistor R714 and the resistor R715 and the voltage between the resistor R716 and the resistor R717 are all connected to the voltage signal input end of the single-chip microcomputer module.

Preferably, the first current detection module and the second current detection module are respectively fixed on both sides of the PCB board of the integrated power battery high voltage detection system.

Preferably, the temperature sensor is fixed on the PCB, and is located between the high-voltage precision resistor R713 and the PCB.

Preferably, the PCB board is provided with four electrical interfaces between the first current detection module and the second current detection module, and the four electrical interfaces include insulation detection and total voltage detection interfaces on one side, and low-voltage signal interfaces. Interface and relay drive interface on the other side, reserved interface.

Preferably, one end of the first current detection module is provided with an interface for connecting the positive input end of the battery, and the other end is provided with an interface for connecting the positive output end of the battery;

One end of the second current detection module is provided with an interface for connecting to the negative input end of the battery, and the other end is provided with an interface for connecting to the negative output end of the battery.

More preferably, the temperature sensor is an infrared temperature sensor.

This scheme is based on the method of insulation verification of the integrated power battery high voltage detection system. The technical scheme is as follows:

Calculate the current difference between the positive input and output terminals and the current difference between the negative input and output terminals according to the measured values of the first current detection module and the second current detection module;

Calculate the positive-to-ground resistance value and the negative-to-ground resistance value according to the current difference of the positive input and output terminals and the current difference of the negative input and output terminals combined with the voltage value measured by the total voltage acquisition module;

Take the minimum value among the calculated positive-to-ground resistance value, negative-to-ground resistance value and the measured value of the insulation detection module, and use the minimum value as the resistance value measured by the integrated power battery high-voltage detection system.

The beneficial effects of the present invention are:

1. A current detection is set in the positive input and output of the battery and the negative input and output respectively, which increases the fault tolerance rate of the current detection, ensures the validity of the current detection data, and improves the safety of the power battery. At the same time, different types of current sensors are used to detect the current, which can further ensure the accuracy of the current detection.

2. The temperature of the entire high-voltage precision resistor is detected by setting the temperature sensor in the air. This temperature has high reference and stability, and is used for temperature compensation in the shunt scheme to ensure the accuracy of high-current detection.

3. Use the difference between the positive and negative poles of the two-way current detection to verify the insulation detection, and take the minimum value to ensure the accuracy of the insulation verification and the safety of the system.

4. Placing the two current sensors on both sides of the PCB can ensure that there is enough space between the two current sensors and effectively reduce the influence of electromagnetic interference on the sampling accuracy.

5. Two parallel interfaces are set on the single-chip microcomputer module, which can receive and process current and voltage data at the same time, and output power and power data synchronously in real time, which effectively improves the operation rate of the system.

Description of drawings

1 is a schematic diagram of the principle of an integrated power battery high-voltage detection system of the present invention;

2 is a schematic diagram of the connection of an integrated power battery high voltage detection system of the present invention;

3 is a schematic diagram of the connection between current detection and voltage detection of the present invention and a single-chip microcomputer module;

4 is a schematic diagram of the layout of a PCB board of an integrated power battery high-voltage detection system of the present invention;

5 is a top view of an integrated power battery high voltage detection system of the present invention;

In the figure: 1. Shunt current sensor, 2. Hall sensor, 3. PCB board, 3-2. Insulation detection and total voltage detection interface, 3-3. Low voltage signal interface, 3-4. Relay drive interface, 3 -5. Reserved interface, 4-1~4-4. Interface.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, so as to facilitate a clear understanding of the present invention, but they do not limit the present invention.

As shown in Figures 1 and 2, an integrated power battery high-voltage detection system includes a single-chip microcomputer module, a total voltage acquisition module, an insulation detection module, a communication module, a power supply module, and also includes a first current detection module and a second current detection module. , the first current detection module is connected between the positive input terminal and the output terminal of the battery, the second current detection module is connected between the negative input terminal and the output terminal of the battery, and the current signals of the first current detection module and the second current detection module output The terminals are all electrically connected to the current signal input terminal of the single-chip module, the voltage signal output terminal of the total voltage acquisition module is electrically connected to the voltage signal input terminal of the single-chip module, and the voltage signal output terminal of the insulation detection module is electrically connected to the resistance signal output terminal of the single-chip module. The resistance signal input end of the single-chip module is electrically connected, the communication module is electrically connected with the communication interface of the single-chip module, and the power module is electrically connected with the power signal input end of the single-chip module; the current sensors used by the current detection module and the second current detection module are of different types current sensor.

The first current detection module is a shunt current sensor 1, a temperature sensor is provided at the center above the high-voltage precision resistor R713 1-1 of the shunt current sensor 1, and a gap is set between the temperature sensor and the surface of the high-voltage precision resistor R713 1-1 .

In this embodiment, the communication module is a CAN communication module. In this scheme, the Hall sensor 2 is used as the reference value, and the shunt current sensor 1 is used as the auxiliary to form mutual verification and improve the safety level.

Among them, the insulation detection module can be expanded, and can collect multiple insulation faults at the same time. The power module and the communication module are isolated by an isolation circuit. The power module and communication module can expand the wake-up function, and at the same time reserve the position of the relay driver chip, which can adapt to the structure of the battery main control board integrated into the vehicle controller, thereby reducing the cost of the battery pack.

This scheme is a method for insulation detection and verification of an integrated power battery high-voltage detection system, including:

Calculate the current difference between the positive input and output terminals and the current difference between the negative input and output terminals according to the measured values of the first current detection module and the second current detection module;

Calculate the positive-to-ground resistance value and the negative-to-ground resistance value according to the current difference of the positive input and output terminals and the current difference of the negative input and output terminals combined with the voltage value measured by the total voltage acquisition module;

Take the minimum value among the calculated positive-to-ground resistance value, negative-to-ground resistance value and the measured value of the insulation detection module, and take the minimum value as the resistance value measured by the integrated power battery high-voltage detection system.

As shown in Figure 3, it also includes a comparator amplifier U605A, the first current detection module is a shunt current sensor 1, the second current detection module is a Hall sensor 2, and the shunt current sensor 1 and the Hall sensor 2 are connected in series on the positive side of the battery. Between the negative poles, the high-voltage precision resistor R7131-1 of the shunt current sensor 1 is connected to the positive terminal of the battery and the inverting input terminal of the comparator amplifier U605A; The opposite input end is connected, and the output end of the comparison amplifier U605A is connected with the current signal input end of the single-chip microcomputer module. The shunt current sensor 1 amplifies the signal through the comparison amplifier, and inputs the signal to the single-chip module for signal acquisition, so as to improve the acquisition accuracy.

The total voltage acquisition module includes a plurality of voltage acquisition circuits arranged in parallel. Specifically, the number of circuits can be adjusted according to the number of sampling points. The voltage acquisition circuit includes resistors R714 to R717, the resistor R714 and the resistor R715 are connected in series between the positive electrode of the battery and the ground, the resistor R716 and the resistor R717 are connected in series between the positive electrode of the battery and the ground, the voltage between the resistor R714 and the resistor R715, the resistor R716 and the ground are connected in series. The voltage between the resistors R717 is connected with the voltage signal input end of the single-chip microcomputer module.

As shown in Figures 4 and 5, the shunt current sensor 1 and the Hall sensor 2 are respectively fixed on both sides of the PCB board 3 of the integrated power battery high voltage detection system. In order to reduce the influence of electromagnetic interference on the sampling accuracy of the Hall sensor 2, the shunt current sensor 1 and the Hall sensor 2 are kept at a certain distance. The PCB board 3 is directly connected to the shunt current sensor 1 and the Hall sensor 2 through the electrical connection hard wire, so as to reduce the contact resistance and sampling error. The temperature sensor is fixed on the PCB board 3 and is located between the high-voltage precision resistor R713 and the PCB board 3 . The temperature sensor is an infrared temperature sensor. The infrared temperature sensor has a certain distance from the high-voltage precision resistor R713 1-1, which is convenient to cover the high-voltage precision resistor R713 1-1. Through the infrared sensor, the overall temperature distribution of the high-voltage precision resistor R713 1-1 can be measured and reflected. In order to avoid the influence of the surrounding switching power supply and surrounding magnetic field devices on the measurement of the Hall sensor 2, the Hall sensor fixing parts are made of plastic parts, and the Hall sensor 2 is far away from the switching power supply components.

The PCB board 3 is provided with four electrical interfaces between the first current detection module and the second current detection module. The four electrical interfaces include an insulation detection and total voltage detection interface 4-1 and a low-voltage signal interface 4-2 on one side. And the relay drive interface 4-3 and reserved interface 4-4 on the other side. One end of the first current detection module is provided with an interface 4-2 for connecting to the positive input end of the battery, and the other end is provided with an interface 4-3 for connecting to the positive output end of the battery; one end of the second current detection module is provided with an interface 4 for connecting to the negative input end of the battery -1, the other end is provided with an interface 4-4 for connecting the negative output end of the battery. The carrier fluid part of each interface can adjust the current-carrying capacity by adjusting the cross-sectional area of the carrier fluid. In order to improve the fixing strength of the interface, an integrated injection molding process is adopted at the interface.

The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (10)

1. An integrated power battery high-voltage detection system, comprising a single-chip microcomputer module, a total voltage acquisition module, an insulation detection module, a communication module, and a power supply module, is characterized in that: also includes a first current detection module and a second current detection module, so The first current detection module is connected between the positive input terminal and the output terminal of the battery, the second current detection module is connected between the negative input terminal and the output terminal of the battery, the first current detection module and the second current detection module The current signal output terminals of the MCU are all electrically connected to the current signal input terminal of the single-chip module, the voltage signal output terminal of the total voltage acquisition module is electrically connected to the voltage signal input terminal of the single-chip module, and the voltage signal output terminal of the insulation detection module is electrically connected to the voltage signal input terminal of the single-chip module. The resistance signal output end of the single-chip module is electrically connected with the resistance signal input end of the single-chip module, the communication module is electrically connected with the communication interface of the single-chip module, and the power module is electrically connected with the power signal input end of the single-chip module; The current sensors used by the current detection module and the second current detection module are different types of current sensors. 2. The integrated power battery high-voltage detection system according to claim 1, wherein the first current detection module is a shunt current sensor (1), and the high-voltage precision resistance of the shunt current sensor (1) A temperature sensor is provided at the central position above R713(1-1), and a gap is provided between the temperature sensor and the surface of the high-voltage precision resistor R713(1-1). 3. The integrated power battery high-voltage detection system according to claim 1, characterized in that: further comprising a comparator amplifier U605A, the first current detection module is a shunt current sensor (1), and the second current detection module is a H Hall sensor (2), the shunt current sensor (1) and the Hall sensor (2) are connected in series between the positive and negative poles of the battery, and the shunt current sensor (1) has a high-voltage precision resistor R713 (1-1 ) The end connected to the positive pole of the battery is connected to the inverting input terminal of the comparator amplifier U605A, and the end of the high-voltage precision resistor R713 (1-1) connected to the Hall sensor (2) is connected to the non-inverting input terminal of the comparator amplifier U605A. The output end of U605A is connected with the current signal input end of the single-chip microcomputer module. 4 . The integrated power battery high voltage detection system according to claim 1 , wherein the total voltage acquisition module comprises a plurality of voltage acquisition circuits arranged in parallel, and the voltage acquisition circuits comprise resistors R714 to R717 , and a resistor R714 . It is connected in series with the resistor R715 between the positive electrode of the battery and the ground, the resistor R716 and the resistor R717 are connected in series between the positive electrode of the battery and the ground, the voltage between the resistor R714 and the resistor R715, and the voltage between the resistor R716 and the resistor R717 are all It is connected with the voltage signal input terminal of the single-chip microcomputer module. 5. The integrated power battery high voltage detection system according to claim 1, wherein the first current detection module and the second current detection module are respectively fixed on the PCB board (3) of the integrated power battery high voltage detection system on both sides. 6. The integrated power battery high-voltage detection system according to claim 2, wherein the temperature sensor is fixed on the PCB board (3), and is located between the high-voltage precision resistor R713 and the PCB board (3). 7. The integrated power battery high voltage detection system according to claim 5, characterized in that: the PCB board (3) is provided with four electrical interfaces between the first current detection module and the second current detection module, four Each of the electrical interfaces includes an insulation detection and total voltage detection interface (4-1) on one side, a low-voltage signal interface (4-2), a relay drive interface (4-3) on the other side, and a reserved interface ( 4-4). 8. The integrated power battery high voltage detection system according to claim 5, wherein: One end of the first current detection module is provided with an interface (4-2) for connecting the positive input end of the battery, and the other end is provided with an interface (4-3) for connecting the positive output end of the battery; One end of the second current detection module is provided with an interface (4-1) for connecting the negative electrode input end of the battery, and the other end is provided with an interface (4-4) for connecting the negative electrode output end of the battery. 9 . The integrated power battery high voltage detection system according to claim 2 , wherein the temperature sensor is an infrared temperature sensor. 10 . 10. A method for insulation detection and verification using the integrated power battery high-voltage detection system according to claim 1, characterized in that: Calculate the current difference between the positive input and output terminals and the current difference between the negative input and output terminals according to the measured values of the first current detection module and the second current detection module; Calculate the positive-to-ground resistance value and the negative-to-ground resistance value according to the current difference of the positive input and output terminals and the current difference of the negative input and output terminals combined with the voltage value measured by the total voltage acquisition module; Take the minimum value among the calculated positive-to-ground resistance value, negative-to-ground resistance value and the measured value of the insulation detection module, and use the minimum value as the resistance value measured by the integrated power battery high-voltage detection system.

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