CN104167804A - Battery management system of mobile energy storing power station - Google Patents

Abstract

The invention relates to a battery management system of a mobile energy storing power station. The battery management system comprises a data collecting module, a battery equalization management module, a temperature equalization management module, a master control module and a power module. The data collecting module is used for collecting operation parameters of the system and uploading the parameters to the master control module. The master control module manages the energy of single batteries according to the system working parameters collected by the data collecting module so that the energy of the single batteries are equalized. The temperature equalization management module collects the temperature of the system in work and controls the temperature within a dynamic range through cooling measures. The master control module analyses and processes the parameters of the data collecting module and control the working state of the battery equalization management module and the working state of the temperature equalization management module according to the parameters. The power module is used for providing stable operation voltage for all the modules. According to the battery management system of the mobile energy storing power station, estimating and monitoring of battery internal states such as the capacity and the SOC are achieved by detecting the external characteristic parameters such as the voltage, the current and the temperature of the batteries and adopting a proper algorithm, and estimating and monitoring of the battery internal states are the basis and the key of the effective operation of the battery management system.

Description

A kind of battery management system of mobile energy-accumulating power station

Technical field

The invention belongs to mobile energy storage technology field, be specifically related to a kind of battery management system of mobile energy-accumulating power station.

Background technology

Energy storage technology is mainly used in stabilizing the fluctuation of solar energy power generating/wind power generation, improves the ability to arrange jobs of electrical network to new forms of energy, has part concurrently to electric-net valley-electricity energy storage peak value power supply function simultaneously.Consider to take into account distributed energy storage and the grid-connected application of scale, energy-storage system should adopt modular assembly to build mode, mainly comprises battery module, battery management system, bidirectional energy-storage current transformer, four layers of framework of monitor protective system from bottom to top.Wherein, battery management system is the control unit that discharges and recharges of whole movable energy storage system, takes into account the collection to system operational parameters simultaneously, and the safe operation of control system is the indispensable part of mobile energy-accumulating power station.The balancing technique of battery management system can change the electric current discharging and recharging between different batteries or charge and discharge accumulative total electric weight, is to solve the battery key technology of consistency difference in groups.The current balance of continuous and effective and correct balanced control strategy, can prevent that consistency difference from appearring in battery, has conclusive effect useful life in groups at battery in index.

Summary of the invention

The invention provides a kind of battery management system of mobile energy-accumulating power station, the state of Real-Time Monitoring battery, the operational factor of acquisition system, after the running status of correctly obtaining battery, carry out battery heat management, battery balanced management, management of charging and discharging and fault alarm etc.

Technical scheme of the present invention is: a kind of battery management system of mobile energy-accumulating power station, and described management system comprises: data acquisition module: the operational factor of acquisition system, and parameter is uploaded to main control module; Battery balanced administration module: main control module, according to the system operational parameters of data collecting module collected, manages the energy of single battery, makes each single battery balancing energy; Temperature equalization administration module: temperature when acquisition system work, makes temperature in a dynamic range by cooling measure; Main control module: the parameter of data acquisition module is carried out to analyzing and processing, and according to the operating state of these parameter controls and battery balanced administration module and temperature equalization administration module; Power module: for modules provides stable working voltage.Described data acquisition module comprises voltage detection unit, current detecting unit and insulating properties detecting unit, and the data of collection are sent to main control module by voltage detection unit, current detecting unit and insulating properties detecting unit.Described current detecting unit adopts Hall current sensor.Between described data acquisition module and main control module, be also connected with light-coupled isolation module, number, the digital signal of data collecting module collected are inputted main control module after light-coupled isolation module.Described battery management system also comprises insulating power supply module, and power module obtains the power supply of voltage detecting, current detecting, insulating properties detecting unit through insulating power supply module.Described power module input front end adds diode to complete reverse protection, strengthens the anti-interference of system.Described battery management system also comprises display module, and display module connects main control module.Described battery management system also comprises alarm module, and alarm module connects main control module.

The present invention has following good effect: 1) Real-Time Monitoring battery status.By detecting the external characteristic parameter (as voltage, electric current, temperature etc.) of battery, adopt suitable algorithm, realize estimation and the monitoring of inside battery state (as capacity and SOC etc.), this is the basic and crucial of the effective operation of battery management system; (2) after the state that correctly obtains battery, carry out heat management, battery balanced management, management of charging and discharging, fault alarm etc.

Brief description of the drawings

Fig. 1 is the system construction drawing of the specific embodiment of the invention.

Embodiment

Contrast accompanying drawing below, by the description to embodiment, the specific embodiment of the present invention is as the effect of the mutual alignment between the shape of related each member, structure, each several part and annexation, each several part and operation principle, manufacturing process and operation using method etc., be described in further detail, to help those skilled in the art to have more complete, accurate and deep understanding to inventive concept of the present invention, technical scheme.

Battery management system refers to parameter information that can Real-Time Monitoring electrokinetic cell, state-of-charge (the State of Charge of estimating battery, SOC), effectively battery capacity managed and distribute, possessing a set of complete system of the functions such as perfect fault detect, warning, data processing and transmission.

Battery management system of the present invention comprises main control module, data acquisition module, display module, battery balanced administration module, temperature equalization administration module, power module and relay control module, main control module is the nucleus module of whole battery management system, carry out the data acquisition of system operational parameters for controlling data acquisition module, and to the data analysis processing of returning, according to the result of data processing, control the operating state of battery balanced administration module and temperature equalization administration module, make the electric quantity balancing of single battery and the temperature of whole system, avoid excess Temperature, damage instrument, reduce useful life.Whether outwards adhesive, disconnection that main control module carrys out control relay by relay control module control battery pack power supply, and power module provides stabilized power supply to various electricity consumption devices.

Data acquisition module comprises voltage detection unit, current detecting unit and insulating properties detecting unit, and the voltage of lithium ion battery best embodies the situation of battery.It is the foundation of lithium ion battery super-charge super-discharge, can also pass through the measuring junction voltage SOC of lithium ion battery according to a preliminary estimate.In car load actual condition, along with the carrying out of battery set charge/discharge, the voltage of battery pack constantly changes, and between cell, the consistency of voltage also can affect the performance of battery pack greatly, so be also necessary to detect the voltage of each cell.Adopt special voltage acquisition chip to carry out, after analog-to-digital conversion, by optocoupler, digital signal being reached to main control module to monomer battery voltage, the accuracy of detection of monomer battery voltage is 10mV.

The operating current of battery pack and temperature are also important parameters of battery pack, and whether it occurred putting and overcurrent can to lead to over-current judging, can also pass through the SOC of ampere-hour method estimating battery.Battery pack is in the actual condition of car load, and the excursion of electric current is-200A is between+500A (precision: 1A), in order to ensure the precision of current acquisition, adopts the shunt that the precision such as gamut are higher to detect battery pack total current.Signal is sent into high-speed AD and is carried out digital-to-analogue conversion and current integration computing after conditioning, and digital signal is inputted main control module and processed after light-coupled isolation, and the detection of electric current generally adopts Hall current sensor.

Whether insulating properties detecting unit is used for the insulation of test judgement power battery pack and car body up to standard, by measuring the voltage between DC bus and electric chassis, calculates the insulating resistance value of system.

Temperature equalization administration module is an important component part of battery system management.The amount of heat that battery produces is at work subject to spatial limitation and accumulates, thereby causes non-uniform temperature everywhere to affect the consistency of battery cell.Therefore will reduce battery charging and discharging cycle efficieny, affect power and the energy performance of battery, when serious, also will cause thermal runaway, affect security of system and reliability.In order to make battery pack bring into play best performance and life-span, need to optimize the structure of power brick, battery pack is carried out to heat management.

The temperature that detects battery pack on the one hand, in order to prevent the too high and excessive temperature differentials of battery pack temperature, prevents security incident; On the other hand, judge the operating state of battery according to the temperature of battery pack, provide foundation for SOC revises.Detected temperatures is generally in battery pack, to add multiple temperature sensors, detects the temperature of each point in battery pack.Because the electric current of dynamical lithium-ion battery packs is often larger.Temperature equalization administration module uploads to system temperature after main control module, and main control module judges whether to take cooling measure according to Current Temperatures, reduces performance to avoid uneven between battery; Eliminate the potential hazard relevant with runaway temperature; By directly or indirectly contacting initiatively or passive heating/cool batteries bag with battery with air, liquid; Ventilation is provided, and the potential pernicious gas that guarantee battery produces can be discharged in time, thereby ensures that battery can safe operation.

The power module that battery management system of the present invention uses is that vehicle-mounted 24V is transformed into 5V, adopts insulating power supply module to obtain voltage detecting, current detecting, insulating properties detection, temperature detection power supply.Add diode to complete reverse protection at power supply input front end, two stage filter circuit is conducive to the anti-interference of system.

The accurate estimation of battery charge state (State of Charge, SOC) is the important evidence that electrokinetic cell discharges and recharges control and energy source optimization management, directly affects the useful life of battery.Visible, the Measurement accuracy of battery dump energy is very crucial problem.But battery SOC can not directly be measured, can only estimate its size by parameters such as battery terminal voltage, charging and discharging currents and internal resistances.And these parameters also can be subject to the impact of the multiple uncertain factors such as cell degradation, variation of ambient temperature and motoring condition, therefore SOC estimates to have become problem demanding prompt solution in electric battery management system accurately.

Choosing battery charging and discharging electric current is system input variable, and battery SOC is state variable, and cell voltage is system output variable.In discrete system, at each sampled point, battery behavior parameter is sampled, as system input variable, the state estimation value in the input variable that algorithm records in conjunction with current time and a upper moment, completes the renewal to state variable and output variable.The present invention adopts expanded Kalman filtration algorithm, calculates the SOC of battery, and its iterative step is as follows:

Step (1): first determine parameter A _k-1, C _k.

$A_{k-1}=\frac{\∂f(x_{k-1},u_{k-1})}{\∂x_{k-1}}=1---\left(1\right)$

$C_k=\frac{\∂y_k}{\∂x_k}=\frac{K_1}{x_k^2}-K_2+\frac{K_3}{x_k}-\frac{K_4}{1-x_k}---\left(2\right)$

Step (2): obtain an initial SOC value SOC ₀all square evaluated error initial value P ₀ ⁺.

$x_0^{+}={\mathrm{SOC}}_0,P_0^{+}=\mathrm{var}\left(x_0\right)---\left(3\right)$

Step (3): obtain prediction SOC value x _k ^-with predicted voltage value y _k ^-.

$x_k^{-}=x_{k-1}^{+}-\left(\frac{{\mathrm{\η}}_i\mathrm{\Δt}}{{\mathrm{\η}}_T{Q}_n}\right)i_k---\left(4\right)$

$y_k^{-}=K_0-{\mathrm{Ri}}_k-\frac{K_1}{x_k^{-}}-K_2{x}_k^{-}+K_3\ln \left(x_k^{-}\right)+K_4\ln (1-x_k^{-})---\left(5\right)$

Step (4): obtain all square evaluated error P of prediction _k ^-, calculate kalman gain L _k.

$P_k^{-}=A_{k-1}{P}_{k-1}^{+}{A}_{k-1}^T+D_w,L_k=\frac{P_k^{-}{C}_k^T}{C_k{P}_k^{-}{C}_k^T+D_w}---\left(6\right)$

Step (5): the optimal estimation x that calculates SOC _k ⁺, all square evaluated error P _k ⁺optimal estimation.

$x_k^{+}=x_k^{-}+L_k(y_k^{+}-y_k^{-}),P_k^{+}=(1-L_k{C}_k)P_k^{-}---\left(7\right)$

By reference to the accompanying drawings the present invention is exemplarily described above; obviously specific implementation of the present invention is not subject to the restrictions described above; as long as adopted the improvement of the various unsubstantialities that method of the present invention design and technical scheme carry out; or without improving, design of the present invention and technical scheme are directly applied to other occasion, all within protection scope of the present invention.

Claims (8)

1. a battery management system for mobile energy-accumulating power station, is characterized in that: described management system comprises:

Data acquisition module: the operational factor of acquisition system, and parameter is uploaded to main control module;

Battery balanced administration module: main control module, according to the system operational parameters of data collecting module collected, manages the energy of single battery, makes each single battery balancing energy;

Temperature equalization administration module: temperature when acquisition system work, makes temperature in a dynamic range by cooling measure;

Main control module: the parameter of data acquisition module is carried out to analyzing and processing, and according to the operating state of these parameter controls and battery balanced administration module and temperature equalization administration module;

Power module: for modules provides stable working voltage.

2. the battery management system of mobile energy-accumulating power station according to claim 1, it is characterized in that: described data acquisition module comprises voltage detection unit, current detecting unit and insulating properties detecting unit, the data of collection are sent to main control module by voltage detection unit, current detecting unit and insulating properties detecting unit.

3. the battery management system of mobile energy-accumulating power station according to claim 2, is characterized in that: described current detecting unit adopts Hall current sensor.

4. the battery management system of mobile energy-accumulating power station according to claim 1, it is characterized in that: between described data acquisition module and main control module, be also connected with light-coupled isolation module, number, the digital signal of data collecting module collected are inputted main control module after light-coupled isolation module.

5. the battery management system of mobile energy-accumulating power station according to claim 1, it is characterized in that: described battery management system also comprises insulating power supply module, power module obtains the power supply of voltage detecting, current detecting, insulating properties detecting unit through insulating power supply module.

6. the battery management system of mobile energy-accumulating power station according to claim 5, is characterized in that: described power module input front end adds diode to complete reverse protection, strengthens the anti-interference of system.

7. the battery management system of mobile energy-accumulating power station according to claim 1, is characterized in that: described battery management system also comprises display module, and display module connects main control module.

8. the battery management system of mobile energy-accumulating power station according to claim 1, is characterized in that: described battery management system also comprises alarm module, and alarm module connects main control module.