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Changes for page 3.4 Battery parameters

Last modified by Admin on 2025/04/09 12:04
From version 30.1
edited by Admin
on 2025/02/17 17:30
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To version 33.3
edited by Admin
on 2025/02/20 14:20
Change comment: There is no comment for this version

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... ... @@ -48,6 +48,8 @@
48 48  * Final SOC – a method of calculating the battery SOC:
49 49  ** Minimum cell SOC – the battery SOC is assumed to be equal to the minimum SOC of cells;
50 50  ** Average cell SOC – the battery SOC is assumed to be equal to the average SOC of cells;
51 +** Min-Max SOC – the battery SOC is calculated based on the minimum and maximum SOC of the cells. Final SOC will be a) 100% if any cell has 100% SOC, b) 0% if any cell has 0% SOC;
52 +** Max-Min SOC – the battery SOC is calculated based on the minimum and maximum SOC of the cells. Final SOC will be a) 100% if all cells have 100% SOC, b) 0% if all cells have 0% SOC;
51 51  * Scale the final SOC – flag to scale the battery SOC by the following values;
52 52  * Internal SOC corresponding to 0% – battery SOC that sets to be 0%;
53 53  * Internal SOC corresponding to 100% – battery SOC that sets to be 100%.
... ... @@ -71,18 +71,26 @@
71 71  
72 72  Calculation of the resistance of cells is carried out in two ways. The first method is used when the battery passes from a relaxation state to a charge or discharge state, wherein the cell resistance value
73 73  
74 -R = (U-Uocv) / Istable,
76 +{{formula fontSize="SMALL" imageType="PNG"}}
77 +R = \frac{U-U_{ocv}}{I_{stable}}
78 +{{/formula}}
75 75  
76 76  where U is the cell voltage measured in the charge or discharge state, V; Uocv is the cell voltage measured in the state of relaxation (before switching to the state of charge or discharge); Istable – stabilized current through the cell in the state of charge or discharge.
77 77  
78 78  The second method is used for a stepwise change in the current through the cell, while the value of the cell resistance:
79 79  
80 -R = (U,,2,,-U,,1,,) / (I,,stable2,,-I,,stable1,,) provided that | I,,stable2,,-I,,stable1,, | > 0.2 × Q,,max,,
84 +{{formula fontSize="SMALL"}}
85 +R = \frac{U_2-U_1}{I_{stable2}-I_{stable1}}
86 +{{/formula}}
81 81  
82 -(Q,,max,, is the maximum cell capacity),
88 +provided that
83 83  
84 -where U,,2,, is the voltage on the cell at the moment when the stabilized current I,,stable2,, is flowing through it; U,,1,, – the voltage on the cell at the moment when the stabilized current I,,stable1,, flowing through it.
90 +{{formula fontSize="SMALL"}}
91 +| I_{stable2}-I_{stable1} | > 0.2 × Q_{max}
92 +{{/formula}}
85 85  
94 +where Q,,max,, is the maximum cell capacity; U,,2,, is the voltage on the cell at the moment when the stabilized current I,,stable2,, is flowing through it; U,,1,, – the voltage on the cell at the moment when the stabilized current I,,stable1,, flowing through it.
95 +
86 86  The stabilized current I,,stable,, = I, if during the stabilization time the instantaneous current I is in the range from 0.95 × I to 1.05 × I.
87 87  
88 88  To change parameters of the algorithm for calculating the cell resistance, select the menu "Cells → Cell resistance estimation":
... ... @@ -247,7 +247,7 @@
247 247  
248 248  === Charge current map ===
249 249  
250 -The BMS Main 2.x board calculates maximum allowable charge current values in respect to SOC and battery temperature, contactor temperature and maximum cell voltage.
260 +The BMS Main 2.x board calculates maximum allowable charge current values in respect to cell SOC and battery temperature, contactor temperature and maximum cell voltage.
251 251  
252 252  Calculated currents values are sending to chargers over the CAN bus.
253 253  
... ... @@ -259,9 +259,9 @@
259 259  
260 260  * Enable – a flag to start calculation of the charge current limit;
261 261  * Maximum charging current – a maximum allowable value of the charge current (under normal conditions):
262 -* Limit charging current by the battery SOC and temperature – a flag to enable correction of maximum allowable charging current Kcs depending on SOC and temperature;
272 +* Limit charging current by the battery SOC and temperature – a flag to enable correction of maximum allowable charging current Kcs depending on the __maximum cell SOC__ and temperature;
263 263  * Limit charging current by the contactor temperature – a flag to enable correction of maximum allowable charging current Kcc depending on the contactor temperature;
264 -* Limit charging current by the maximum cell voltage – a flag to enable correction of maximum allowable charging current Kcv depending on maximum cell voltage;
274 +* Limit charging current by the maximum cell voltage – a flag to enable correction of maximum allowable charging current Kcv depending on __the maximum cell voltage__;
265 265  * Limit charging current by the maximum cell temperature – a flag to enable correction of maximum allowable charging current Kct depending on cell temperature.
266 266  
267 267  Value of the charge current limit at given SOC, temperature, contactors temperature and maximum cell voltage is calculated as follows: