CN204515094U - A kind of electric battery SOC estimating system - Google Patents

Abstract

The utility model provides a kind of electric battery SOC estimating system, comprises voltage detection module, current detection module, temperature sensor, data acquisition module, control module, display module and host computer, and described control module comprises SOC evaluation unit; Described voltage detection module, current detection module are connected described control module with temperature sensor by described data acquisition module, and described control module connects display module, and is connected to host computer by CAN.The utility model is by the collection analysis to each operational factor, comprise open-circuit voltage, electric current, temperature, adopt the mathematical method of Estimating The Model Coefficients, set up the battery model being applicable to hybrid vehicle accumulator index more accurately, guarantee the accuracy of electric battery SOC algorithm for estimating.

Description

A kind of electric battery SOC estimating system

Technical field

The utility model belongs to power safety technique field, is specifically related to a kind of electric battery SOC estimating system.

Background technology

Since nineteen nineties, lithium ion battery, as one of the developing direction of New Energy Industry, is subject to the attention of more and more domestic and international researcher, and achieves great progress.In application process, lithium ion battery discharge and recharge conversion is frequent, electric current is larger, to the dynamic perfromance of battery model, the precision estimation of battery charge state (battery charge state is called for short the abbreviation that SOC, SOC are State ofCharge), the performance of direct relation battery management system.The SOC of battery is used to the residual capacity situation reflecting battery.SOC estimation method mainly contains the method for ampere-hour method, open-circuit voltage method, internal resistance method, Kalman filtering method, neural network and fuzzy reasoning.The ampere-hour method of current employing is carried out the SOC of estimating battery, and compensate SOC according to the temperature of battery and discharge rate.This method is simple and easy to, algorithmic stability, but along with the accumulation of time, error can be increasing.Open-circuit voltage method is according to the corresponding relation between the open-circuit voltage of battery and the depth of discharge of battery, estimates SOC by the open-circuit voltage measuring battery.The advantage of the method: load method can the SOC of real-time estimation electric battery when constant-current discharge, and electric current is big ups and downs in practice, so adopt separately load method effect unsatisfactory.During practical application, open-circuit voltage method is often combined with ampere-hour method, and the SOC for the initial stage of charging and latter stage estimates.Load method is rarely used in reality, but is commonly used to the criterion as battery charging and discharging cut-off.Internal resistance measurement method is the relation utilized between internal resistance and SOC, estimates SOC by measuring internal resistance.Under actual condition, the change of electric current is very fast, and the calculating of therefore internal resistance is very complicated.Internal resistance method is applicable to the SOC estimation in electric discharge later stage, can combinationally use with ampere-hour method.Because method is complicated, the calculating of internal resistance is off-line case substantially, and calculated amount is large, is therefore rarely used in reality.

Utility model content

One of the utility model object is to provide a kind of electric battery SOC estimating system, to this system overcomes in prior art ampere-hour method along with the accumulation of time, and error increasingly can wait technical barrier, and improves SOC estimation precision.

A kind of electric battery SOC estimating system that the utility model provides, comprise voltage detection module, current detection module, temperature sensor, data acquisition module, control module, display module and host computer, described control module comprises SOC evaluation unit.

Described voltage detection module, current detection module are connected described control module with temperature sensor by described data acquisition module, and described control module connects described display module, and is connected to host computer by CAN.

Further, described control module adopts the single-chip microcomputer of STC89C51 model.

The beneficial effects of the utility model are, by the collection analysis to each operational factor, comprise open-circuit voltage, electric current, temperature, adopt the mathematical method of Estimating The Model Coefficients, set up the battery model being applicable to hybrid vehicle accumulator index more accurately, guarantee the accuracy of electric battery SOC algorithm for estimating.

Accompanying drawing explanation

Figure 1 shows that the utility model electric battery SOC estimating system structural representation.

Embodiment

Hereafter will describe the utility model in detail in conjunction with specific embodiments.It should be noted that the combination of technical characteristic or the technical characteristic described in following embodiment should not be considered to isolated, they can mutually be combined thus be reached better technique effect.

As shown in Figure 1, a kind of electric battery SOC estimating system that the utility model provides, comprise voltage detection module 1, current detection module 2, temperature sensor 3, data acquisition module 4, control module 5, display module 6 and host computer 7, control module 5 comprises SOC evaluation unit 8.

Voltage detection module 1, current detection module 2 are connected described control module 5 with temperature sensor 3 by described data acquisition module 4, and control module 5 connects display module 6, and are connected to host computer 7 by CAN.

Control module 5 adopts the single-chip microcomputer of STC89C51 model.

Voltage detection module 1 and current detection module 2 are for detecting the voltage and current of battery, temperature sensor 3 is for gathering the temperature of battery, data acquisition module 4 is for by voltage detection module 1, the data that current detection module 2 and temperature sensor 3 collect are transferred to SOC evaluation unit 8, control module 5 according to the estimation of battery SOC estimation unit 8 to the duty after each data analysis, the duty of battery being judged and control to load, display module 6 is connected in control module 5 for showing information, control module 5 is connected to host computer 7 by CAN, for the voltage to battery, electric current, temperature and SOC comprehensively analyze, control and measure.

Electric battery SOC estimating system is estimated by following steps: step one, carry out initialization to system, and battery management system is to battery parameter identification; Step 2, in the discharge and recharge starting stage, select open-circuit voltage method, determine the value of state SOC0; React not acute phase at inside battery, calculated the value of SOC by ampere-hour method; At inside battery reaction acute phase, calculated the value of SOC1 by Kalman filtering method, and value is fed back to battery management system, and show on PC computer; Step 3, battery management system will be received value of feedback and be deposited into two-dimensional data table, and after one-period T, battery management system judges next round SOC estimation method according to the data of two-dimensional data table, carry out next round to battery parameter identification, perform step 2.Step 4, battery management system system send halt instruction, and whole process terminates.Described step one initialization procedure comprises setting battery capacity, open-circuit voltage, and conversion coulombic efficiency, BMS sampling time, built-up pattern parameter, setting Kalman filtering calculate initial value.Described two-dimensional data table comprises battery parameter Identification Data and SOC value data, and what finally export is the result that two kinds of method weightings obtain.

Although given embodiments more of the present utility model, it will be understood by those of skill in the art that when not departing from the utility model spirit herein, can change embodiment herein.Above-described embodiment is exemplary, should using embodiment herein as the restriction of the utility model interest field.

Claims (2)

1. an electric battery SOC estimating system, is characterized in that, comprises voltage detection module, current detection module, temperature sensor, data acquisition module, control module, display module and host computer, and described control module comprises SOC evaluation unit;

Described voltage detection module, current detection module are connected described control module with temperature sensor by described data acquisition module, and described control module connects described display module, and is connected to host computer by CAN.

2. a kind of electric battery SOC estimating system as claimed in claim 1, is characterized in that, described control module adopts the single-chip microcomputer of STC89C51 model.