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Changes for page 3.4 Battery parameters

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1 -drafts.bms-main-2-1.configuration.WebHome
1 +drafts.bms-main-2.configuration.WebHome
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2 2  
3 3  To change the default cell settings, select the menu "Cells → Cell defaults":
4 4  
5 -[[Cell default section>>image:1732205873121-893.png||data-xwiki-image-style-alignment="center" height="313" width="416"]]
5 +[[image:1732205873121-893.png||data-xwiki-image-style-alignment="center" height="313" width="416"]]
6 6  
7 7   In this section:
8 8  
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31 31  
32 32  To change the parameters of the algorithm for calculating the battery SOC, select the menu "Cells → SOC estimation":
33 33  
34 -[[SOC estimation section>>image:1732206031847-819.png||data-xwiki-image-style-alignment="center" height="849" width="356"]]
34 +[[image:1732206031847-819.png||data-xwiki-image-style-alignment="center" height="849" width="356"]]
35 35  
36 36  In this section:
37 37  
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81 81  
82 82  To change parameters of the algorithm for calculating the cell resistance, select the menu "Cells → Cell resistance estimation":
83 83  
84 -[[Cell resistance estimation settings>>image:1732207338609-903.png||data-xwiki-image-style-alignment="center" height="187" width="337"]]
84 +[[image:1732207338609-903.png||data-xwiki-image-style-alignment="center" height="187" width="337"]]
85 85  
86 86  In this section:
87 87  
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119 119  
120 120  To change the cell balancing parameters, select the menu "Cell → Cell balancing":
121 121  
122 -[[Cell balancing settings>>image:1732207485773-804.png||data-xwiki-image-style-alignment="center" height="264" width="387"]]
122 +[[image:1732207485773-804.png||data-xwiki-image-style-alignment="center" height="264" width="387"]]
123 123  
124 124  In this section:
125 125  
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151 151  
152 152  To change the series balancing parameters, select the menu "Cell → Series balancing":
153 153  
154 -[[Series balancing settings>>image:1732207584941-447.png||data-xwiki-image-style-alignment="center" height="258" width="438"]]
154 +[[image:1732207584941-447.png||data-xwiki-image-style-alignment="center" height="258" width="438"]]
155 155  
156 156  In this section:
157 157  
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162 162  * Coulomb threshold – the difference of the charges Qthr, given by a series of cells, above which balancing to be started, Ah;
163 163  * Period – period to reset of charge counters for each series (to avoid accumulation of error), second.
164 164  
165 -== ==
165 +== 3.4.6 Cell analysis ==
166 166  
167 -== ==
167 +Discharge characteristics of the battery – the dependence Uocv = Uocv (DOD) – is used to determine the tabular dependence Uocv = Uocv (SOC, t °C) (see section Calculating the state of charge (SOC)), which is necessary for calculating the state of charge of the battery.
168 168  
169 -== SOC correction ==
169 +The BMS Main 2.x board can automatically determine the battery discharge characteristic.
170 170  
171 +Before starting the process of determining the discharge characteristic, it is necessary to prepare a BMS:
172 +
173 +1. Charge the battery.
174 +1. Connect a contactor to the discharging relay which switches the resistive load to the battery.
175 +1. Connect a resistive load to the contactor, which will provide a discharge current of 0.5C (where C is the cell capacitance).
176 +
177 +To configure parameters for determining the discharge characteristic of the battery, select the menu "Cells → Cell analysis":
178 +
179 +[[image:1732207696322-587.png||data-xwiki-image-style-alignment="center" height="213" width="258"]]
180 +
181 +In this section:
182 +
183 +* Enable – a flag to enable cell analysis;
184 +* Discharge step, Ah;
185 +* Delta voltage – a maximum allowable voltage drop for the cell, V;
186 +* Logic index – an address of the BMS Logic board to which the analyzed cell is connected;
187 +* Cell index – a position of the analyzed cell connected to the BMS Logic board;
188 +* Analyse cell with minimum voltage – a flag to analyse of the least charged cell (in this case, the values of Logic index and Cell index are ignored).
189 +
190 +Discharge step should be set equal to
191 +
192 +Discharge step = С/21,
193 +
194 +where C is the cell capacity.
195 +
196 +The discharge characteristic will be constructed for the given cell (its position is determined by the fields Logic index and Cell index).
197 +
198 +The algorithm for determining the discharge characteristic of the battery will be started if the Enable flag is set. From this moment, the control of the discharge relay is performed by this algorithm.
199 +
200 +Algorithm steps:
201 +
202 +1. DOD = 0.
203 +1. Disconnecting the discharge relay.
204 +1. Waiting for the relaxation of the battery.
205 +1. Measuring Uocv = U.
206 +1. Saving the point of the discharge characteristic (Q, U,,OCV,,).
207 +1. Activation of the discharge relay. DOD,,1,, = DOD + Discharge step, U,,1,, = U
208 +1. If DOD = DOD,,1,, or U < (U,,1,, – Delta voltage), then go to step 2.
209 +1. If the "Undervoltage" error is detected, then the end of the algorithm.
210 +
211 +During the operation of the algorithm, a file with the name "CELLANALYSIS.TXT" in the CSV format will be created on the SD card.
212 +
213 +File structure:
214 +
215 +|**Time**|**DOD**|**Logic**|**Cell**|**OCV**|**Resistance**
216 +|**10.11.2017 12:28:34**|0.0|1|1|4.180|0.080000
217 +|**...**|...|…|…|...|...
218 +
219 +Parameter names:
220 +
221 +* Time – date and time;
222 +* DOD – depth of discharge, Ah;
223 +* Logic – the address of the BMS Logic board to which the analyzed cell is connected;
224 +* Cell – position of the analyzed cell for which OCV and Resistance values are provided;
225 +* OCV – cell voltage Uocv, V;
226 +* Resistance – cell resistance, Ohm.
227 +
228 +== 3.4.7 Charge current map ==
229 +
230 +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.
231 +
232 +Calculated currents values are sending to chargers over the CAN bus.
233 +
234 +To configure parameters for determining the charge current limit, select the menu "Cells → Charge current map":
235 +
236 +[[image:1732208033738-498.png||data-xwiki-image-style-alignment="center" height="655" width="453"]]
237 +
238 +In this section:
239 +
240 +* Enable – a flag to start calculation of the charge current limit;
241 +* Maximum charging current – a maximum allowable value of the charge current (under normal conditions):
242 +* 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;
243 +* Limit charging current by the contactor temperature – a flag to enable correction of maximum allowable charging current Kcc depending on the contactor temperature;
244 +* Limit charging current by the maximum cell voltage – a flag to enable correction of maximum allowable charging current Kcv depending on maximum cell voltage;
245 +* Limit charging current by the maximum cell temperature – a flag to enable correction of maximum allowable charging current Kct depending on cell temperature.
246 +
247 +Value of the charge current limit at given SOC, temperature, contactors temperature and maximum cell voltage is calculated as follows:
248 +
249 +Charging current limit = Maximum charging current × Kcs × Kcc × Kcv × Kct.
250 +
251 +== 3.4.8 Discharge current map ==
252 +
253 +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.
254 +
255 +Calculated currents values are sending or intellectual loads over the CAN bus.
256 +
257 +To configure parameters for determining the charge current limit, select the menu "Cells → Charge current map":
258 +
259 +[[image:1732208218667-968.png||data-xwiki-image-style-alignment="center" height="631" width="434"]]
260 +
261 +In this section:
262 +
263 +* Enable – a flag to start calculation of the discharge current limit;
264 +* Maximum discharging current – a maximum allowable value of the discharge current (under normal conditions):
265 +* Current factor – the dependence of the correction factor on SOC and the battery temperature – Kdischarge=Kdischarge (SOC, t°C).
266 +* Limit discharging current by the battery SOC and temperature – a flag to enable correction of maximum allowable discharging current Kds depending on SOC and temperature;
267 +* Limit discharging current by the contactor temperature – a flag to enable correction of maximum allowable discharging current Kdc depending on the contactor temperature;
268 +* Limit discharging current by the maximum cell voltage - a flag to enable correction of maximum allowable discharging current Kdv depending on maximum cell voltage;
269 +* Limit discharging current by the maximum cell temperature - a flag to enable correction of maximum allowable discharging current Kdt depending on cell temperature .
270 +
271 +Value of the discharge current limit at given SOC, temperature, contactors temperature and maximum cell voltage is calculated as follows:
272 +
273 +Discharging current limit = Maximum discharging current × Kds × Kdc × Kdv × Kdt.
274 +
275 +== 3.4.9 SOC correction ==
276 +
171 171  The BMS Main 2.x board can recalculate the battery SOC after long-term storage or after long-term working in the case when the battery was not charged fully or discharged totally. Recalculation is done based on the tabular dependency Uocv = Uocv (SOC, t) (see section Calculating the state of charge (SOC)).
172 172  
173 173  To configure parameters for periodically correcting the battery state of charge, select the menu "Cells → SOC correction":
174 174  
175 -[[SOC correction settings>>image:1732206262509-786.png||data-xwiki-image-style-alignment="center" height="291" width="298"]]
281 +[[image:1732206262509-786.png||data-xwiki-image-style-alignment="center" height="291" width="298"]]
176 176  
177 177   In this section:
178 178  
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179 179  * Enable – a flag to enable SOC correction;
180 180  * Shutdown period – a time the battery is off, day. If the BMS detects on its startup that it was off during the “Shutdown period” time, the BMS recalculates the battery state of charge base on the tabular dependency Uocv = Uocv (SOC, t);
181 181  * Correction period – a period of correcting the battery SOC, day. If the BMS detects that the last correction was more than the “Correction period” ago, the BMS recalculates the battery state of charge base on the tabular dependency Uocv = Uocv (SOC, t) and tunes it gradually during the “SOC change time”;
182 -* SOC change time – a duration of the linear changing the battery SOC to the value calculated by the correction algorithm, minute.
288 +* SOC change time – a duration of the linear changing the battery SOC to the value calculated by the correction algorithm, minute;
289 +* Ignore the linear zone – a flag to ignore linear zone while calculating SOC correction.
183 183  
184 184  
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