CN101504444A - Battery capacity check method for electric car matrix battery pack - Google Patents

Abstract

The invention relates to batteries of electric automobiles, in particular to a method for detecting battery capacity of a matrix battery pack of the electric automobiles, which is characterized by comprising the following steps: adopting a serially and parallelly connected storage battery matrix battery pack, and connecting nodes of various storage batteries in the matrix battery pack by a same resistor so as to form a balancing resistance network; sampling current signals serially connected with each row of the storage batteries in the balancing resistance network, and sampling voltage signals of other rows of nodes in each line relative to nodes in the first row; obtaining sizes and directions of all current flowing through the batteries through calculation; obtaining electric quantity conditions of all batteries in the matrix network through integration; and obtaining various capacity fading tables of the batteries in the balancing resistance network by analyzing electric quantity data of the batteries in the storage battery balancing resistance network in the charging or discharging process; therefore, the method detects and judges battery capacity fading conditions in a matrix, and replaces the batteries with quick battery capacity fading in the matrix to improve the battery capacity of the matrix storage battery pack and reduce the replacement cost of the storage batteries.

Description

The battery capacity check method of electric car matrix electric battery

Technical field

The present invention relates to the batteries of electric automobile class, specifically is a kind of battery capacity check method of electric car matrix electric battery.

Background technology

At the disposable input cost height of existing accumulator of electric car, battery is short serviceable life, problems such as accumulator renewal cost height, our company changes traditional concept, proposed to adopt series-parallel accumulator matrix to connect, applied for that application number is that " 200910096144.0 ", name are called the patent of invention of " a kind of battery wire laying method of electric automobile ", the rectangular that has proposed the batteries of electric automobile group is arranged, simultaneously each single battery is carried out sample detecting and management.But when according to present method each battery being carried out capacity check, comparatively loaded down with trivial details, battery management, replacing, maintenance still are that underaction is convenient.

Summary of the invention

The objective of the invention is deficiency, provide a kind of and can simply monitor out in real time each single-unit accumulator capacity, be convenient to the battery capacity check method of the electric car matrix electric battery of battery detecting and replacing, maintenance at above-mentioned technology.

Technical scheme of the present invention is as follows:

A kind of battery capacity check method of electric car matrix electric battery, it is characterized in that: adopt series-parallel accumulator matrix electric battery, in the matrix electric battery, all use a same resistance to link to each other between the node of every joint accumulator, form the balance resistance network, reaching the effect that matrix between each accumulator connects, and utilize this resistance that each accumulator is reached equilibrium activity; The current signal of every row battery pack series connection in the sampling balance resistance network, other each the row nodes in every row of sampling are with respect to the first row voltages at nodes signal; By computing obtain flowing through all size of current and the direction of each batteries; Obtain the battery condition of all batteries in the matrixing network by integration; By the electric quantity data analysis of battery in charging or the discharge process accumulator balance resistance network, obtain each inducing capacity fading table of battery in the balance resistance network, thereby detect the battery capacity decline situation in the matrix of judging; Replace the fast battery of battery capacity decline in the matrix, can improve the battery capacity of matrix battery pack, reduce the replacement cost of accumulator.

The present invention is because the balance resistance network can also effectively promote freely moving of electric weight between the battery; the battery that guaranteed capacity is high can farthest be released the electric weight of self; the low battery of capacity also can effectively be protected in the matrix battery network simultaneously, has evaded in the series battery because the single-unit backwardness causes the phenomenon of whole Battery pack performance rapid deterioration.And then farthest bring into play the maximum economic benefit of matrix battery network.

The present invention detects the current value of the series connection battery pack of each row at current sensor of negative pole series connection of each row battery.

The present invention is to its magnitude of voltage of node measurement of each accumulator of the row of first in the matrix electric battery; Utilize the magnitude of voltage of each node that is listed as each accumulator and the current value of Ge Lie, calculate each current value of flowing through of joint accumulator, and obtain the capacity of each accumulator, by data sampling, A/D conversion, data processing is calculated and decision making.

The present invention has designed the data acquisition of a kind of accumulator cell charging and discharging of single-unit cheaply, calculating and management method, can realize the real-time detection of single battery capacity, the operation conditions of monitoring whole group matrix accumulator and single accumulator, can promptly and accurately determine the bad accumulator in the matrix electric battery, and change this joint accumulator in good time, to guarantee the consistance of each batteries of matrix battery pack, realize effectively electric charge resettlement between accumulator, prolong accumulator serviceable life, reduce the electric motor car use cost.The present invention can be applicable to fields such as electric automobile and mixed power electric car.

Description of drawings

Fig. 1 is capable for m of the present invention, the matrix electric battery of n row detects schematic diagram.

Fig. 2 is the ij accumulator node current network operations schematic diagram of Fig. 1.

Fig. 3 detects schematic diagram for the matrix electric battery embodiment of the present invention's 4 row, 4 row.

Embodiment

As shown in Figure 1, The present invention be directed to that m is capable, carry out the resistor network connection between the node of each accumulator of matrix electric battery of n row, all use a resistance R between each accumulator node ₀Connect.For the principle of work of explaining the detection of matrix electric battery is done following explanation earlier:

(1) battery position numbering: row that the 1st sequence number that numeral is expert at for this battery, the 2nd numeral are the battery column number.What for example ij represented is that i is capable, the battery of j row.Get a node at the positive pole place of each batteries, node number is this battery sequence number.

(2) electric current positive dirction regulation: for ij piece battery, for electric current on the column direction, downwards for just, promptly battery is emitted electric current for just.For the column direction electric current, be positive dirction to flow into the present node direction of current.

(3) current sample: above the first row battery,, obtain the size of current that flows into each row battery in first row, also be battery 11,21,31 by n current sampling resistor ..., the discharge current I of n1 ₁, I ₂, I ₃..., I _n

(4) connect a resistance balance network between cell row and the row, make that any two internodal resistance are equal in n the node with delegation, make that this resistance is R.The electromotive force at node i j place is φ _IjAs Fig. 2, appoint the node i j that gets the capable j row of i place to analyze, the electromotive force of this point is φ _IjAt t constantly, can get formula 1 to ij point place utilization Kirchhoff's current law (KCL):

I ∈ (1, m) j ∈ (1, n) (formula 1)

From formula 1 as can be seen

Can by

Release.Earlier the electric current that can obtain flowing out n battery on first row by the current sampling resistor on matrix first row is seen formula 2.Now the sampling network on capable by i can record the voltage U between i1 node and the arbitrary node ij _Ji1Because resistance R is known, can obtain any two node U _IsAnd U _IjBetween voltage see formula 3.

I _J1=I _jJ ∈ (1, n) (formula 2)

$=U_{\mathrm{si}1}-U_{\mathrm{ji}1}$ (formula 3)

Can obtain any time arbitrary node place cell instantaneous discharge current by formula 1, formula 2, formula 3

To t ₀Electric current in the-t time period carries out integration can obtain battery ij discharge electricity amount Q in this time period _Ij, see formula 4.

$Q_{\mathrm{ij}}(t_0,t)=\underset{t_0}{\overset{t}{\∫}}\left(I_{\mathrm{ij}}t\right)$ (formula 4)

Be carved into t during from t0 constantly by battery, battery ij discharge electricity amount Q _IjConstitute the electric weight matrix and see formula 5.

(formula 5)

Patrol and examine the electric weight Q of each point joint place in the electric weight matrix _Ij, and calculate current electric quantity matrix mean value E (Q (t ₀, t)), extrapolate Δ Q _Ij(t ₀, t)=Q _Ij-E (Q (t ₀, t)).

(formula 6)

The present invention establishes a battery protecting circuit, measures a battery capacity safety constant by experiment, if when the inducing capacity fading data of battery are lower than this safe constant in the balance resistance network, battery protecting circuit provides alerting signal to the user.

If measure a safe constant p by experiment, p be one less than

Safety coefficient.Under perfect condition, the electric weight criterion t of matrix battery is 0.The maximal value of the t consistance of baby battery more is just good more.

T=Δ Q _Ij(t ₀, t)/E (Qt ₀, t))≤p (warning)

P (safety) (formula 7)

With the accumulator is 12V12AH, and forming 4*4 accumulator matrix group is that embodiment (as shown in Figure 3) does a description to embodiment: by the balance resistance network, the equivalent resistance between each node is R, and is constantly as shown in table 1 to the circuit analysis of each node at t:

Node number	Inflow current	Flow out electric current
			11	I 11+(U 211+U 311+U 411)/R	I 21＝I 11+(U 211+U 311+U 411)/R
21	I 21+(U 121+U 321+U 421)/R	I 31＝I 21+(U 121+U 321+U 421)/R
			31	I 31+(U 231+U 331+U 431)/R	I 41＝I 31+(U 231+U 331+U 431)/R
41	I 41
			12	I 12+(U 112+U 312+U 412)/R	I 22＝I 12+(U 112+U 312+U 412)/R
22	I 22+(U 122+U 322+U 422)/R	I 32＝I 22+(U 122+U 322+U 422)/R
			32	I 32+(U 132+U 332+U 432)/R	I 42＝I 32+(U 132+U 332+U 432)/R
42	I 42
			13	I 13+(U 113+U 213+U 413)/R	I 23＝I 13+(U 113+U 213+U 413)/R

23	I 23+(U 123+U 223+U 423)/R	I 33＝I 21+(U 123+U 223+U 423)/R
			33	I 33+(U 133+U 233+U 433)/R	I 43＝I 31+(U 133+U 233+U 433)/R
43	I 43
			14	I 14+(U 114+U 214+U 314)/R	I 21＝I 14+(U 114+U 214+U 314)/R
24	I 24+(U 124+U 224+U 324)/R	I 31＝I 24+(U 124+U 224+U 324)/R
			34	I 34+(U 134+U 234+U 334)/R	I 41＝I 34+(U 134+U 234+U 334)/R
44	I 44

From t ₀In time period constantly, the electric weight that flows out each batteries is as shown in table 2 to t:

Table 2

By to the resolving of balance resistance network, can obtain single battery in the matrix electric battery t0 to t constantly battery capacity change.By Δ Q _Ij(t ₀, t)=Q _Ij-E (Q (t ₀, t)) and calculate in the battery network single battery inducing capacity fading criterion matrix t as shown in Equation 8 with reference to formula 7:

$t=\left[\begin{array}{cccc}{t}_{11}& t_{12}& t_{13}& t_{14}\\ t_{21}& t_{22}& t_{23}& t_{24}\\ t_{31}& t_{32}& t_{33}& t_{34}\\ t_{41}& t_{42}& t_{43}& {\mathrm{<figure-callout\; id="44"\; label="t"\; filenames="A200910097119E00131.png"\; state="\{\{state\}\}">t</figure-callout>}}_{44}\end{array}\right]$

Formula 8

Suppose the situation that significantly fails to have occurred, so the angry t of the battery capacity criterion that should locate at the battery at the 2nd row the 3rd row place ₂₃＜p.If when the continuous appearance of this decline criterion was lower than p 3 times, battery protecting circuit will provide alerting signal to the user.

The user can in time detect this group matrix battery with special-purpose detecting instrument to professional matrix battery maintenance store after seeing matrix battery alarm signal, finds out the battery of inducing capacity fading and changes it.

Claims (4)

1, a kind of battery capacity check method of electric car matrix electric battery is characterized in that: adopt series-parallel accumulator matrix electric battery, all use a same resistance to link to each other in the matrix electric battery between the node of every joint accumulator, form the balance resistance network; The current signal of every row battery pack series connection in the sampling balance resistance network, other each the row nodes in every row of sampling are with respect to the first row voltages at nodes signal; By computing obtain flowing through all size of current and the direction of each batteries; Obtain the battery condition of all batteries in the matrixing network by integration; By the electric quantity data analysis of battery in charging or the discharge process accumulator balance resistance network, obtain each inducing capacity fading table of battery in the balance resistance network, thereby detect the battery capacity decline situation in the matrix of judging.

2, the battery capacity check method of electric car matrix electric battery according to claim 1 is characterized in that: at current sensor of negative pole series connection of each row battery, detect the current value of the series connection battery pack of each row.

3, the battery capacity check method of electric car matrix electric battery according to claim 1 and 2, it is characterized in that: utilize the magnitude of voltage of each node that is listed as each accumulator and the current value of Ge Lie, calculate the current value that each joint accumulator flows through, and obtain the capacity of each accumulator, by data sampling, A/D conversion, data processing is calculated and decision making.

4, the battery capacity check method of electric car matrix electric battery according to claim 1 and 2; it is characterized in that: establish a battery protecting circuit; measure a battery capacity safety constant by experiment; if when the inducing capacity fading data of battery were lower than this safe constant in the balance resistance network, battery protecting circuit provided alerting signal to the user.

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