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Changes for page 3.4 Battery parameters

Last modified by Admin on 2025/04/09 12:04
From version 31.3
edited by Admin
on 2025/02/20 11:09
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To version 33.2
edited by Admin
on 2025/02/20 14:20
Change comment: There is no comment for this version

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... ... @@ -73,24 +73,26 @@
73 73  
74 74  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
75 75  
76 -R = (U-Uocv) / Istable,
76 +{{formula fontSize="SMALL" imageType="PNG"}}
77 +R = \frac{U-U_{ocv}}{I_{stable}}
78 +{{/formula}}
77 77  
78 78  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.
79 79  
80 80  The second method is used for a stepwise change in the current through the cell, while the value of the cell resistance:
81 81  
82 -R = (U,,2,,-U,,1,,) / (I,,stable2,,-I,,stable1,,)
84 +{{formula fontSize="SMALL"}}
85 +R = \frac{U_2-U_1}{I_{stable2}-I_{stable1}}
86 +{{/formula}}
83 83  
84 84  provided that
85 85  
86 -~{~{formula fontSize="SMALL"}}
87 -~| I_{stable2}-I_{stable1} | > 0.2 × Qmax
88 -~{~{/formula}}
90 +{{formula fontSize="SMALL"}}
91 +| I_{stable2}-I_{stable1} | > 0.2 × Q_{max}
92 +{{/formula}}
89 89  
90 -(Q,,max,, is the maximum cell capacity),
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.
91 91  
92 -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.
93 -
94 94  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.
95 95  
96 96  To change parameters of the algorithm for calculating the cell resistance, select the menu "Cells → Cell resistance estimation":
... ... @@ -255,7 +255,7 @@
255 255  
256 256  === Charge current map ===
257 257  
258 -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.
259 259  
260 260  Calculated currents values are sending to chargers over the CAN bus.
261 261  
... ... @@ -267,10 +267,10 @@
267 267  
268 268  * Enable – a flag to start calculation of the charge current limit;
269 269  * Maximum charging current – a maximum allowable value of the charge current (under normal conditions):
270 -* 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;
271 271  * Limit charging current by the contactor temperature – a flag to enable correction of maximum allowable charging current Kcc depending on the contactor temperature;
272 -* Limit charging current by the maximum cell voltage – a flag to enable correction of maximum allowable charging current Kcv depending on maximum cell voltage;
273 -* Limit charging current by the maximum cell temperature – a flag to enable correction of maximum allowable charging current Kct depending on cell temperature.
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__;
275 +* Limit charging current by the maximum cell temperature – a flag to enable correction of maximum allowable charging current Kct depending on thecell temperature.
274 274  
275 275  Value of the charge current limit at given SOC, temperature, contactors temperature and maximum cell voltage is calculated as follows:
276 276