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Changes for page 3.4 Battery parameters

Last modified by Admin on 2025/04/09 12:04
From version 29.1
edited by Admin
on 2025/02/17 17:28
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To version 33.4
edited by Admin
on 2025/02/20 14:22
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":
... ... @@ -134,7 +134,7 @@
134 134  
135 135  To change the cell balancing parameters, select the menu "Cell → Cell balancing":
136 136  
137 -[[image:1732207485773-804.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="264" width="387"]]
147 +[[image:1739812799920-892.png||alt="1732207485773-804.png" data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="264" width="387"]]
138 138  
139 139  In this section:
140 140  
... ... @@ -146,8 +146,13 @@
146 146  ** Charging;
147 147  ** Charging or relaxed;
148 148  ** Always (regardless of battery state);
159 +* Balancing condition:
160 +** Automatic – balancing will be performed automatically if needed conditions are met;
161 +** On balancing request – balancing will start only if a remote request is received. In this case cells will start to balance regardless the "Voltage deviation to start balancing" value;
149 149  * Minimum cell voltage to start balancing, V;
150 -* Balancing threshold, V;
163 +* Deviation to start balancing;
164 +* Deviation to stop balancing;
165 +* Voltage for forced balancing – if cell voltage is above this value, it will start discharging through balancing resistor;
151 151  * Start cell discharging – a command to start forced balancing of all battery cells (used for service purposes);
152 152  * Stop cell discharging – a command to stop forced balancing of all battery cells (used for service purposes).
153 153  
... ... @@ -242,7 +242,7 @@
242 242  
243 243  === Charge current map ===
244 244  
245 -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.
246 246  
247 247  Calculated currents values are sending to chargers over the CAN bus.
248 248  
... ... @@ -254,9 +254,9 @@
254 254  
255 255  * Enable – a flag to start calculation of the charge current limit;
256 256  * Maximum charging current – a maximum allowable value of the charge current (under normal conditions):
257 -* 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;
258 258  * Limit charging current by the contactor temperature – a flag to enable correction of maximum allowable charging current Kcc depending on the contactor temperature;
259 -* 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__;
260 260  * Limit charging current by the maximum cell temperature – a flag to enable correction of maximum allowable charging current Kct depending on cell temperature.
261 261  
262 262  Value of the charge current limit at given SOC, temperature, contactors temperature and maximum cell voltage is calculated as follows:
... ... @@ -265,7 +265,7 @@
265 265  
266 266  === Discharge current map ===
267 267  
268 -The BMS Main 2.x board calculates maximum allowable discharge current values in respect to SOC and battery temperature, contactor temperature and maximum cell voltage.
283 +The BMS Main 2.x board calculates maximum allowable discharge current values in respect to cell SOC and battery temperature, contactor temperature and minimum cell voltage.
269 269  
270 270  Calculated currents values are sending or intellectual loads over the CAN bus.
271 271