CN208937642U

CN208937642U - Smart current sensor based on double shunt

Info

Publication number: CN208937642U
Application number: CN201821620614.XU
Authority: CN
Inventors: 李扬
Original assignee: Lanzhou University of Technology
Current assignee: Lanzhou University of Technology
Priority date: 2018-09-30
Filing date: 2018-09-30
Publication date: 2019-06-04
Anticipated expiration: 2028-09-30

Abstract

The utility model proposes an intelligent current sensor based on double shunts, which comprises two shunts, one of which is connected in a charging circuit and the other in a discharging circuit, and the output ends of the two shunts are respectively connected to the output ends of the electricity meter chip. Input terminals, the output terminals of the two fuel gauge chips are respectively connected to the input terminals of the arithmetic single-chip microcomputer, and the arithmetic single-chip microcomputer is connected to the subsequent communication device. The utility model uses two shunts, which are respectively responsible for the current of the charging loop and the discharging loop, and the range of each shunt can be determined according to the current upper limit of the loop, thereby improving the measurement accuracy. The utility model adopts the electricity meter, which can realize high-speed measurement of current, thereby improving the accuracy of current measurement. In addition, the digital signal output by the electricity meter has strong anti-interference ability, and finally makes the SOC estimation more accurate.

Description

Intelligent current sensor based on double split flow device

Technical field

The utility model relates to current sensors.

Background technique

SOC full name is State of Charge, state-of-charge, is also remaining capacity, representative be battery using one section when Between or for a long time lie idle after residual capacity and its fully charged state capacity ratio.Usually it is to the estimation of SOC value It is calculated by the current sampling circuit being made of current divider, single-chip microcontroller etc..Current divider is actually the electricity of a resistance value very little Resistance, for converting voltage signal for the electric current for flowing through itself, in order to carry out current sample to battery pack.Under normal circumstances, One battery pack only will use a current divider, i.e., when battery charges and discharges, electric current all flows through this current divider.But Be, in most cases discharge current can be higher than charging current, therefore the range of current divider would generally according to the discharge current upper limit come It determines.So, when battery charges, charging current can only use the sub-fraction of current divider range, greatly reduce survey Accuracy of measurement.

On the other hand, the voltage of current divider output is differential voltage, need converted device be converted into single ended voltage export again to Single-chip microcontroller, single ended voltage are analog signal, and the route between converter and single-chip microcontroller is longer, and transmission process is extremely vulnerable to dry It disturbs, and the speed of single-chip microcontroller monitoring voltage is that Millisecond is other, voltage error is big, certainly will influence the estimation precision of final SOC.

Utility model content

There is interference and the low estimation precision so as to cause final SOC of measurement accuracy to solve existing current sample process Low problem proposes a kind of Intelligent current sensor based on double split flow device, following scheme is used to be achieved:

A kind of Intelligent current sensor based on double split flow device, including two-way current divider, connect in charge circuit, separately all the way It connects in discharge loop all the way, the output end of two-way current divider is connected respectively to the input terminal of voltameter chip, two voltameter cores The output end of piece is connected respectively to the input terminal of operation single-chip microcontroller, and operation single-chip microcontroller connects subsequent communications device.

Further, the voltameter chip uses MAX17260.

Further, in the discharge loop current divider range be greater than charge circuit in current divider range.

Further, the operation single-chip microcontroller uses STM32F103C8T6.

Further, it is digital signal that the voltameter chip, which is output to the signal in single-chip microcontroller,.

Further, the operation single-chip microcontroller by CAN interface or crosses RS485 interface connection subsequent communications device.

Further, the subsequent communications device is control single chip computer.

Compared with prior art, it the advantages of the utility model and has the active effect that

The utility model uses two current dividers, is each responsible for the electric current of detection battery charge circuit and discharge loop, often The range of a current divider can be determined according to the upper current limit in this circuit, so as to improve the precision of measurement.The utility model Using voltameter, high speed may be implemented and measure electric current to improve the precision of current measurement, the number that in addition voltameter exports Signal, strong antijamming capability finally make SOC valuation more accurate.

Detailed description of the invention

Fig. 1 is Intelligent current sensor circuit functional block diagram of the utility model based on double split flow device.

Specific embodiment

The utility model is described in more detail with reference to the accompanying drawings and detailed description.

With reference to Fig. 1, Intelligent current sensor of the present embodiment based on double split flow device includes two-way current divider (one above in figure Road is the first via, is below all the way the second tunnel), voltameter and operation single-chip microcontroller, first via current divider be connected in charge circuit, The output end of current divider connects the differential input end of the first voltameter, and the of the output end connection operation single-chip microcontroller of the first voltameter One second input terminal；No. second current divider is connected in discharge loop, and the output end of current divider connects the difference of the second voltameter Input terminal, the 3rd the 4th input terminal of the output end connection operation single-chip microcontroller of the second voltameter.

Usual battery discharge current is higher than charging current, therefore the range of the present embodiment current divider is according to charging and discharging currents Depending on the upper limit, the range setting of current divider is greater than the range of current divider in charge circuit in discharge loop, in this way, each divide The range of stream device can be determined according to the upper current limit in this circuit, to improve the precision of measurement.

The voltage of current divider output is differential voltage, i.e., voltage reference is not GND, and the present embodiment selects Maxim MAX17260 voltameter come measure current divider generation differential voltage.MAX17260 also has a coulomb counter, can be in high speed While measuring electric current, measurement result is added to a coulomb counter, realizes the automatic integration of electric current.Operation single-chip microcontroller can be with MAX17260 communicates to configure MAX17260, and obtains the electric current of charge circuit and discharge loop and the electric current of coulomb counter Accumulated value.In single-chip microcontroller, electric current accumulated value is multiplied with the current sample period of MAX17260, as the electricity that has used of battery Amount.On the other hand, the signal of MAX17260 voltameter output is digital signal, although MAX17260 voltameter and operation monolithic are straight The cabling connect is longer, analog signal transmission bring interference effect before overcoming.

The present embodiment operation single-chip microcontroller uses STM32F103C8T6, can be by CAN interface and RS485 interface for communicating.

The present embodiment Intelligent current sensor passes through two-way diverter designs and cooperation voltameter and operation chip microcontroller To the precise measurement of electric current, and to external equipment for example subsequent control single chip computer directly export precise measurement charging current, The SOC value of discharge current and battery pack.

The above descriptions are merely preferred embodiments of the present invention, is not to make other forms to the utility model Limitation, any person skilled in the art is changed or is modified as possibly also with the technology contents of the disclosure above equivalent The equivalent embodiment of variation is applied to other fields, but all without departing from the content of the technical scheme of the utility model, according to this reality With novel technical spirit any simple modification, equivalent variations and remodeling to the above embodiments, it is practical new to still fall within this The protection scope of type technical solution.

Claims

1. a kind of intelligent current sensor based on double shunt, it is characterized in that: comprise two-way shunt, one way is connected in the charging loop, the other way is connected in the discharging loop, the output end of the two-way shunt is connected to the electricity meter respectively The input end of the chip and the output ends of the two fuel gauge chips are respectively connected to the input end of the arithmetic single-chip microcomputer, and the arithmetic single-chip microcomputer is connected to the subsequent communication device.

2 . The intelligent current sensor based on dual shunts according to claim 1 , wherein the fuel gauge chip adopts MAX17260. 3 .

3 . The intelligent current sensor based on dual shunts according to claim 1 , wherein the range of the shunt in the discharge loop is greater than the range of the shunt in the charging loop. 4 .

4 . The intelligent current sensor based on dual shunts according to claim 1 , wherein the arithmetic single-chip microcomputer adopts STM32F103C8T6. 5 .

5 . The intelligent current sensor based on dual shunts according to claim 1 , wherein the signal output by the fuel gauge chip to the single-chip microcomputer is a digital signal. 6 .

6 . The intelligent current sensor based on dual shunts according to claim 4 , wherein the arithmetic single-chip microcomputer is connected to a subsequent communication device through a CAN interface. 7 .

7 . The intelligent current sensor based on dual shunts according to claim 4 , wherein the arithmetic single-chip microcomputer is connected to a subsequent communication device through an RS485 interface. 8 .

8 . The intelligent current sensor based on dual shunts according to claim 6 or 7 , wherein the subsequent communication device is a control single-chip microcomputer. 9 .