Current signal acquisition circuit of household energy storage battery

Abstract

The current signal acquisition circuit of the household energy storage battery comprises a current signal acquisition device, and the current signal acquisition device comprises a diverter, a filtering unit, an amplification unit, an AD isolation unit, an AD sampling unit and a control unit. Current signals are converted into voltage signals through a shunt arranged in the current signal collector, common-mode noise is eliminated through a common-mode inductor, high-frequency noise is filtered out through a filter circuit, the signals are amplified through an amplifying circuit, the amplifying circuit is powered by double power supplies to ensure the integrity of the signals, the signals are isolated through an isolating chip, and therefore the current signals are obtained. And finally, the signal is transmitted to the control unit for signal conversion, and the analog quantity is converted into the digital quantity, so that compared with a traditional acquisition circuit, the precision and the safety are higher, and the working state is more stable.

Description

Technical Field

[0001] The utility model relates to the technical field of battery pipelines, in particular to a current signal acquisition circuit for a household energy storage battery. Background Art

[0002] Under the advocacy of green energy, battery modules, as the energy source of household energy storage products, play an irreplaceable role in the entire system and are becoming increasingly popular among the public. In household energy storage battery modules, the current signal of the system battery must be collected in real time to ensure that household energy storage products work within the specified current range. If fault information occurs, the system current status can be understood at the first time, and the fault can be eliminated in time to ensure the safety of the battery module, while providing the safest protection system for household energy storage products. Because the current signal is a key electrical parameter in the battery management system, it is necessary to collect and monitor the current variation range of the battery system in real time to avoid current collection errors, which may lead to abnormal system operation or device overheating. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a current signal acquisition circuit for a household energy storage battery with high accuracy, high safety and stable working state.

[0004] The technical problem to be solved by the utility model is achieved through the following technical solutions: a current signal acquisition circuit for a household energy storage battery, comprising a current signal collector for collecting current signals of a household energy storage battery, a current signal collector shunt, a filtering unit, an amplifying unit, an AD isolation unit, an AD sampling unit and a control unit;

[0005] The filtering circuit comprises a resistor R1, a resistor R2, a resistor R3, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a common-mode inductor L1 and a common-mode inductor L2; one end of the resistor R1 is electrically connected to one end of the common-mode inductor L1, and the other end is electrically connected to one end of the common-mode inductor L2; one end of the capacitor C1 is electrically connected between one end of the resistor R1 and one end of the common-mode inductor L1, and the other end is electrically connected between the other end of the resistor R1 and one end of the common-mode inductor L2; one end of the resistor R2 is electrically connected to the common-mode inductor L1, and the other end is electrically connected to the common-mode inductor L2. The other end of the common-mode inductor L1 is electrically connected; one end of the resistor R3 is electrically connected to the other end of the common-mode inductor L2; one end of the capacitor C2 is electrically connected between one end of the resistor R2 and the other end of the common-mode inductor L1, and the other end of the capacitor C2 is electrically connected between one end of the resistor R3 and the other end of the common-mode inductor L2; one end of the capacitor C3 is electrically connected to the other end of the resistor R2, one end of the capacitor C4 is electrically connected to the other end of the resistor R3, and the other end of the capacitor C3 is electrically connected to the other end of the capacitor C4 and is grounded.

[0006] Preferably, the amplification unit includes an operational amplifier I, the ends of the resistor R2 and the capacitor C3 of the filtering unit electrically connected to each other are electrically connected to the positive input terminal of the operational amplifier I, and the ends of the resistor R3 and the capacitor C4 electrically connected to each other are electrically connected to the reverse input terminal of the operational amplifier I; a resistor R5 is connected in series between pins 2 and 3 of the operational amplifier I; pin 5 of the operational amplifier I is electrically connected to a 15V power supply; pin 6 of the operational amplifier I is electrically connected to a reference power supply REF; pin 7 of the operational amplifier I is electrically connected to a resistor R6, and the other end of the resistor R6 is electrically connected to a resistor R7.

[0007] Preferably, it also includes an operational amplifier II, wherein pin I of the operational amplifier II is electrically connected to a 5V power supply; the ends of the resistors R6 and R7 electrically connected to each other are electrically connected to resistor R8, and the other end of resistor R8 is electrically connected to pin 2 of the operational amplifier II; pin 3 of the operational amplifier II is electrically connected to resistor R9; pin 4 of the operational amplifier II is electrically connected to the other end of resistor R9 and is grounded; pin 5 of the operational amplifier II is connected to the reference ground of the current signal acquisition circuit; pin 6 of the operational amplifier II is the reverse input terminal of the operational amplifier II; pin 7 of the operational amplifier II is the forward input terminal of the operational amplifier II; and pin 8 of the operational amplifier II is connected to a 5V power supply.

[0008] Compared with the prior art, the beneficial technical effect of the utility model is: the current signal is converted into a voltage signal through a shunt, the common mode noise is eliminated through a common mode inductor, the high frequency noise is filtered out through a filter circuit, and the signal is amplified through an amplifier circuit. The amplifier circuit adopts a dual power supply to ensure the integrity of the signal, and then the signal is isolated through an isolation chip to reduce external interference. Finally, the signal is transmitted to the control unit for signal conversion, and the analog quantity is converted into a digital quantity. Compared with the traditional acquisition circuit, the accuracy and safety are higher, and the working state is more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a system block diagram of the utility model;

[0010] Figure 2 This is the filter circuit diagram of the utility model;

[0011] Figure 3 This is the circuit diagram of the operational amplifier I of the utility model;

[0012] Figure 4 This is the circuit diagram of the operational amplifier II of the utility model. DETAILED DESCRIPTION

[0013] The specific technical solutions of the present invention are further described below with reference to the accompanying drawings, so as to facilitate further understanding of the present invention by those skilled in the art, and do not constitute any limitation to the rights thereof.

[0014] Example 1, reference Figure 1-4 A current signal acquisition circuit for a household energy storage battery includes a current signal collector for collecting current signals from a household energy storage battery. The current signal collector includes a shunt, a filter unit, an amplification unit, an AD isolation unit, an AD sampling unit, and a control unit. The isolation chip, sampling chip model, and microcontroller chip model of the AD isolation unit, the AD sampling unit, and the control unit can be selected according to the use requirements.

[0015] The filtering circuit comprises a resistor R1, a resistor R2, a resistor R3, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a common-mode inductor L1 and a common-mode inductor L2; one end of the resistor R1 is electrically connected to one end of the common-mode inductor L1, and the other end is electrically connected to one end of the common-mode inductor L2; one end of the capacitor C1 is electrically connected between one end of the resistor R1 and one end of the common-mode inductor L1, and the other end is electrically connected between the other end of the resistor R1 and one end of the common-mode inductor L2; one end of the resistor R2 is electrically connected to the common-mode inductor L1, and the other end is electrically connected to the common-mode inductor L2. The other end of the common-mode inductor L1 is electrically connected; one end of the resistor R3 is electrically connected to the other end of the common-mode inductor L2; one end of the capacitor C2 is electrically connected between one end of the resistor R2 and the other end of the common-mode inductor L1, and the other end of the capacitor C2 is electrically connected between one end of the resistor R3 and the other end of the common-mode inductor L2; one end of the capacitor C3 is electrically connected to the other end of the resistor R2, one end of the capacitor C4 is electrically connected to the other end of the resistor R3, and the other end of the capacitor C3 is electrically connected to the other end of the capacitor C4 and is grounded.

[0016] Embodiment 2, a current signal acquisition circuit for a household energy storage battery as described in Embodiment 1, wherein the amplification unit comprises an operational amplifier I, the ends of the resistor R2 and the capacitor C3 of the filtering unit electrically connected to each other are electrically connected to the positive input end of the operational amplifier I, and the ends of the resistor R3 and the capacitor C4 electrically connected to each other are electrically connected to the reverse input end of the operational amplifier I; a resistor R5 is connected in series between pins 2 and 3 of the operational amplifier I; pin 5 of the operational amplifier I is electrically connected to a 15V power supply; pin 6 of the operational amplifier I is electrically connected to a reference power supply REF; pin 7 of the operational amplifier I is electrically connected to a resistor R6, and the other end of the resistor R6 is electrically connected to a resistor R7.

[0017] Embodiment 3, a current signal acquisition circuit for a household energy storage battery described in Embodiment 2, further includes an operational amplifier II, wherein pin I of the operational amplifier II is electrically connected to a 5V power supply; the ends of the resistors R6 and R7 electrically connected to each other are electrically connected to resistor R8, and the other end of resistor R8 is electrically connected to pin 2 of the operational amplifier II; pin 3 of the operational amplifier II is electrically connected to resistor R9; pin 4 of the operational amplifier II is electrically connected to the other end of resistor R9 and is grounded; pin 5 of the operational amplifier II is connected to a reference ground of the current signal acquisition circuit; pin 6 of the operational amplifier II is the reverse input terminal of the operational amplifier II; pin 7 of the operational amplifier II is the forward input terminal of the operational amplifier II; and pin 8 of the operational amplifier II is connected to a 5V power supply.

[0018] In order to ensure the integrity of the signal, we connect pin 5 of operational amplifier I to a 15V power supply, pin 6 to a reference power supply REF, and pin 1 of operational amplifier II to a 5V power supply, and pin 8 to a 5V system power supply, so that both operational amplifier I and operational amplifier II are configured with dual power supply;

[0019] The operating principle of the current signal acquisition circuit of the household energy storage battery is:

[0020] The current signal of the household energy storage battery is converted into a voltage signal through the shunt of the current signal acquisition circuit of the household energy storage battery, the common mode noise is eliminated through the common mode inductor, and the high frequency noise is filtered out through the filter circuit, and then the signal is amplified through the amplifier circuit, and then the signal is isolated through the AD isolation unit, that is, the isolation chip, so as to reduce external interference. In order to ensure the isolation effect, the isolation module can be powered separately, and finally the signal is given to the control unit, that is, the main control module MCU, so as to perform signal conversion and convert the analog quantity into digital quantity.

Claims

1. A current signal acquisition circuit for household energy storage batteries, characterized in that: A current signal collector for collecting current signals from household energy storage batteries, the current signal collector comprising a shunt, a filter unit, an amplification unit, an AD isolation unit, an AD sampling unit and a control unit; The filtering unit includes a resistor R1, a resistor R2, a resistor R3, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a common-mode inductor L1 and a common-mode inductor L2; one end of the resistor R1 is electrically connected to one end of the common-mode inductor L1, and the other end is electrically connected to one end of the common-mode inductor L2; one end of the capacitor C1 is electrically connected between one end of the resistor R1 and one end of the common-mode inductor L1, and the other end is electrically connected between the other end of the resistor R1 and one end of the common-mode inductor L2; one end of the resistor R2 is electrically connected to the common-mode inductor L1, and the other end is electrically connected to the common-mode inductor L2. The other end of the common-mode inductor L1 is electrically connected; one end of the resistor R3 is electrically connected to the other end of the common-mode inductor L2; one end of the capacitor C2 is electrically connected between one end of the resistor R2 and the other end of the common-mode inductor L1, and the other end of the capacitor C2 is electrically connected between one end of the resistor R3 and the other end of the common-mode inductor L2; one end of the capacitor C3 is electrically connected to the other end of the resistor R2, one end of the capacitor C4 is electrically connected to the other end of the resistor R3, and the other end of the capacitor C3 is electrically connected to the other end of the capacitor C4 and is grounded.

2. The current signal acquisition circuit of a household energy storage battery according to claim 1, characterized in that: The amplification unit includes an operational amplifier I, the ends of the resistor R2 and the capacitor C3 of the filtering unit electrically connected to each other are electrically connected to the positive input end of the operational amplifier I, and the ends of the resistor R3 and the capacitor C4 electrically connected to each other are electrically connected to the reverse input end of the operational amplifier I; a resistor R5 is connected in series between pins 2 and 3 of the operational amplifier I; pin 5 of the operational amplifier I is electrically connected to a 15V power supply; pin 6 of the operational amplifier I is electrically connected to a reference power supply REF; pin 7 of the operational amplifier I is electrically connected to a resistor R6, and the other end of the resistor R6 is electrically connected to a resistor R7.

3. The current signal acquisition circuit of a household energy storage battery according to claim 2, characterized in that: It also includes an operational amplifier II, wherein pin I of the operational amplifier II is electrically connected to a 5V power supply; the ends of the resistors R6 and R7 electrically connected to each other are electrically connected to resistor R8, and the other end of resistor R8 is electrically connected to pin 2 of the operational amplifier II; pin 3 of the operational amplifier II is electrically connected to resistor R9; pin 4 of the operational amplifier II is electrically connected to the other end of resistor R9 and is grounded; pin 5 of the operational amplifier II is connected to the reference ground of the current signal acquisition circuit; pin 6 of the operational amplifier II is the reverse input terminal of the operational amplifier II; pin 7 of the operational amplifier II is the forward input terminal of the operational amplifier II; and pin 8 of the operational amplifier II is connected to a 5V power supply.

Images