Wiki source code of 3.3 Control

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1 (% data-numbered-headings-start="3" style="--numbered-headings-start: 2;font-size: 0px;color: rgba(0, 0, 0, 0.0);margin-bottom: 0px; margin-top: 0px;" %)
2 = Settings =
3
4 (% data-numbered-headings-start="3" style="--numbered-headings-start: 2;font-size: 0px;color: rgba(0, 0, 0, 0.0);margin-bottom: 0px; margin-top: 0px;" %)
5 == Control ==
6
7 === Common settings ===
8
9 To change the common BMS settings, select the "Control → Common settings" section:
10
11 [[image:1740394523706-519.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="127" width="800"]]
12
13 In this section:
14
15 * Cell capacity – nominal capacity of cells, Ah;
16 * Cell resistance – nominal (maximum) internal resistance of the cell, Ohm;
17 * Relax time (after charging) – a relaxation time after charging, second;
18 * Relax time (atfer discharging) – the relaxation time after discharging, second;
19 * Reset parameters– a command to reset cells state of charge, capacity, and resistance.
20
21 The values “Capacity” and “Resistance” are used to calculate the SOC of cells and the battery.
22
23 The values of “Relax time” are used to determine the state of the battery. If the battery is in a state of relaxation, the system recalculates the voltage on the cells to the state of charge of the battery.
24
25 The “Reset parameters” will reset:
26
27 * state of charge (new cell SOC values will be calculated based on cell voltage and “Uocv (open-circuit voltage) table”: in the “Control → SOC estimation” section);
28 * cell resistance to “Cell resistance” value;
29 * battery capacity to “Cell capacity” value.
30
31 The “Reset parameters” command is used for starting-up and adjustment of the battery.
32
33 === SOC estimation ===
34
35 The BMS Mini device calculates the state of charge of the battery (SOC) using two algorithms:
36
37 * by open circuit voltage;
38 * by voltage and current.
39
40 It is recommended to use the algorithm of calculation of SOC by voltage and current.
41
42 To change the estimation algorithm for calculating the battery SOC, select the "Control → SOC estimation → Algorithm" section:
43
44 [[image:1733746733477-590.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="166" width="800"]]
45
46 The following estimation algorithms supported:
47
48 * Voltage – by open circuit voltage;
49 * Current and voltage (simplified);
50 * Current and voltage (enhanced);
51
52 The **“Voltage”** SOC calculation algorithm calculates cells SOC based on the tabular dependence Uocv = Uocv(SOC, t °C).
53
54 The **“Current and voltage (simplified)”** SOC calculation algorithm works as follows:
55
56 * if I = 0, the battery is in a state of relaxation and the cell voltage Uocv is outside the [U,,ocv[point 1],,; U,,ocv[point 2],,], the SOC calculation based on the tabular dependence Uocv = Uocv(SOC, t °C);
57 * in any other cases, the SOC value is proportional to the charge (coulomb) passed through the battery (current time integral).
58
59 The **“Current and voltage (enhanced)” **SOC calculation algorithm differs from the simplified algorithm by online correction of effective capacitance. When using this algorithm, it is necessary to fine tune the tabular dependence Uocv = Uocv (SOC, t °C).
60
61 To change the algorithm for calculating the Final SOC, select the "Control → SOC estimation → Final SOC" section:
62
63 [[image:1733746733478-414.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="167" width="800"]]
64
65 The following battery Final SOC calculation methods are supported:
66
67 * Minimal SOC – SOC of the modular battery is assumed to be the minimum SOC among the battery modules;
68 * Average SOC – SOC of the modular battery is taken equal to the arithmetic average of the SOC of the battery modules;
69 * 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;
70 * 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.
71
72 Other parameters:
73
74 * Scale the final SOC – a flag to scale the battery SOC by the following values;
75 * SOC corresponding to 0% – the battery SOC that sets to be 0%;
76 * SOC corresponding to 100% – the battery SOC that sets to be 100%.
77 * Uocv (open-circuit voltage) table – the dependence of the cell open circuit voltage Uocv on SOC and the cell temperature (selected for specific batteries);
78 * Linear zone - linear zone of the Uocv = Uocv(SOC, t°C) dependency, inside which the cell voltage changes insignificantly:
79 ** Linear zone: point 1 – starting point of the Uocv linear zone;
80 ** Linear zone: point 2 – ending point of the Uocv linear zone;
81 * Coulomb counting correction (temperature) – the dependence of battery capacity on temperature;
82 * Coulomb counting correction (cycles) – the dependence of battery capacity on the number of charge-discharge cycles.
83
84 === SOC correction ===
85
86 The BMS Mini device 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 [[SOC estimation>>doc:||anchor="HSOCestimation"]]).
87
88 To configure parameters for periodically correcting the battery state of charge, select the "Control → SOC correction" section:
89
90 [[image:1733746733483-444.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="160" width="800"]]
91
92 In this section:
93
94 * Enable – a flag to enable SOC correction;
95 * 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 based on the tabular dependency Uocv = Uocv (SOC, t);
96 * 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 based on the tabular dependency Uocv = Uocv (SOC, t) and tunes it gradually during the “SOC change time”.
97 * SOC change time – a duration of the linear changing the battery SOC to the value calculated by the correction algorithm, minute;
98 * Ignore the linear zone – a flag to ignore linear SOC zone while correction;
99 * Last correction timestamp – time when last correction was made.
100
101 === Resistance estimation ===
102
103 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
104
105 {{formula fontSize="SMALL" imageType="PNG"}}
106 R = \frac{U-U_{ocv}}{I_{stable}}
107 {{/formula}}
108
109 where U is the cell voltage measured in the charge or discharge state, V; U,,ocv,, is the cell voltage measured in the state of relaxation (before switching to the state of charge or discharge); I,,stable,, – stabilized current through the cell in the state of charge or discharge.
110
111 The second method is used for a stepwise change in the current through the cell, while the value of the cell resistance:
112
113 {{formula fontSize="SMALL"}}
114 R = \frac{U_2-U_1}{I_{stable2}-I_{stable1}}
115 {{/formula}}
116
117 provided that
118
119 {{formula fontSize="SMALL"}}
120 | I_{stable2}-I_{stable1} | > 0.2 × Qmax
121 {{/formula}}
122
123 where Q,,max,, — the maximum cell capacity,U,,2,, — 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.
124
125 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.
126
127 To change parameters of the algorithm for calculating the cell resistance, select the "Control → Resistance estimation" section:
128
129 [[image:1733746733484-681.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="104" width="800"]]
130
131 In this section:
132
133 * Current stabilization time, millisecond;
134 * Maximum calculation period – maximum time between resistance measurements. If more time has elapsed since the last determination of the stabilized current I,,stable,, than is determined in this field, the resistance calculation is not performed, second;
135 * Maximum resistance factor – the coefficient of calculation of the maximum acceptable resistance of the cell;
136 * Minimum SOC – minimum cell SOC value for resistance calculation;
137 * Maximum SOC – maximum cell SOC value for resistance calculation.
138
139 The calculated resistance is accepted by the system as valid (and therefore updated) if its value is in the range from Resistance/2 to “Maximum resistance factor” × Resistance, where "Resistance" is the nominal resistance of the cell (see [[Common settings>>doc:||anchor="HCommonsettings"]]). If the calculated resistance value is greater than the value (Maximum resistance factor × Resistance), the updated resistance value will be equal to the value (Maximum resistance factor × Resistance).
140
141 === Low SOC (signal) ===
142
143 To change the parameters of the generation a signal about low battery level, select the "Control → Low SOC (signal)" section:
144
145 [[image:1740396460923-423.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="141" width="800"]]
146
147 In this section:
148
149 * Enable – a flag to enable signal generation;
150 * Minimum SOC, %;
151 * Tolerant SOC, %;
152 * Delay before setting the signal, second;
153 * Delay before clearing the signal, second;
154 * Lock – lock the signal until the device is reset.
155
156 Signal generation conditions:
157
158 * the battery SOC is less than the “Minimum SOC” value during the “Delay before setting the signal” time.
159
160 Conditions for clearing the signal:
161
162 * the battery SOC is greater than the “Tolerant SOC” during the “Delay before clearing the signal” time.
163
164 (% class="box infomessage" %)
165 (((
166 The "Low SOC signal" is indicative and can be output to a discrete output or a power switch.
167 )))
168
169 === High charging current (signal) ===
170
171 To change the parameters of the generation high-current signal, select the "Control → High charging current (signal)" section:
172
173 [[image:1740396996935-403.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="144" width="800"]]
174
175 In this section:
176
177 * Enable – a flag to enable signal generation;
178 * Maximum charging current, А;
179 * Tolerant charging current, А;
180 * Delay before setting the signal, second;
181 * Delay before clearing the signal, second;
182 * Lock – lock the signal until the device is reset.
183
184 Signal generation conditions:
185
186 * the measured current is greater than the “Maximum charging current” value during the “Delay before setting the signal” time.
187
188 Conditions for clearing the signal:
189
190 * the measured current is less than the “Tolerant charging current” value during the “Delay before clearing the signal” time.
191
192 (% class="box infomessage" %)
193 (((
194 The "High charging current" signal is indicative and can be output to a discrete output or a power switch.
195 )))
196
197 === Charge map ===
198
199 The BMS Mini device calculates maximum allowable charge current values in respect to SOC, battery temperature, contactor temperature and cell voltage.
200
201 Calculated current values are sending to a charger or an intellectual load over the CAN bus.
202
203 To configure parameters for determining the charge current limit, select the "Control → Charge map" section:
204
205 [[image:1740397188247-315.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="179" width="800"]]
206 In this section:
207
208 * Enable – a flag to start calculation of the charge current limit;
209 * Maximum charge current – a maximum allowable value of the charge current (under normal conditions), A;
210 * Rate of change – a rate of change the current limit to a new value (0 is for immediate change), A/s;
211 * Option 1: Limit charge current by the battery SOC and temperature – a flag to enable correction of maximum allowable charging current** Kcs** depending on SOC and battery temperature;
212 * Option 1: SOC x Temperature x Factor – the dependence of the correction factor on SOC and battery temperature;
213 * Option 2: Limit charge current by the contactor temperature – a flag to enable correction of maximum allowable charging current **Kcc** depending on contactor temperature;
214 * Option 2: Contactor temperature x Factor – the dependence of the correction factor on SOC and contactor temperature;
215 * Option 3: Limit charge current by the maximum cell voltage - a flag to enable correction of maximum allowable charging current **Kcv** depending on maximum cell voltage;
216 * Option 3: Cell voltage x Factor – the dependence of the correction factor on maximum cell voltage;
217 * Option 4: Limit charge current by the cell temperature - a flag to enable correction of maximum allowable charging current **Kct** depending on maximum cell temperature;
218 * Option 4: Cell temperature x Factor – the dependence of the correction factor on maximum cell temperature.
219
220 Value of the charge current limit at given SOC, temperature, contactors temperature, maximum cell voltage and maximum cell temperature is calculated as follows:
221
222 **Charge current limit = Maximum charge current × Kcs × Kcc × Kcv × Kct**
223
224 === Discharge map ===
225
226 The BMS Mini device calculates maximum allowable discharge current values in respect to SOC, battery temperature, contactor temperature and cell voltage.
227
228 Calculated current values are sending to a charger or an intellectual load over the CAN bus.
229
230 To configure parameters for determining the discharge current limit, select the "Control → Discharge map" section:
231
232 [[image:1740397304972-174.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="182" width="800"]]
233
234 In this section:
235
236 * Enable – a flag to start calculation of the discharge current limit;
237 * Maximum discharge current – a maximum allowable value of the discharge current (under normal conditions), A;
238 * Rate of change – a rate of change the current limit to a new value (0 is for immediate change), A/s;
239 * Option 1: 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;
240 * Option 1: SOC x Temperature x Factor – the dependence of the correction factor on SOC and battery temperature;
241 * Option 2: Limit discharge current by the contactor temperature – a flag to enable correction of maximum allowable discharging current **Kdc** depending on contactor temperature;
242 * Option 2: Contactor temperature x Factor – the dependence of the correction factor on SOC and contactor temperature;
243 * Option 3: Limit discharge current by the cell voltage - a flag to enable correction of maximum allowable discharging current **Kdv** depending on minimum cell voltage;
244 * Option 3: Cell voltage x Factor – the dependence of the correction factor on minimum cell voltage;
245 * Option 4: Limit discharge current by the cell temperature - a flag to enable correction of maximum allowable discharging current **Kdt** depending on maximum cell temperature;
246 * Option 4: Cell voltage x Factor – the dependence of the correction factor on minimum cell temperature.
247
248 Value of the discharge current limit at given SOC, temperature, contactors temperature, minimum cell voltage and maximum cell temperature is calculated as follows:
249
250 **Discharge current limit = Maximum discharge current × Kds × Kdc × Kdv × Kdt**
251
252 === Main contactor ===
253
254 The BMS Mini device controls the main contactor. The main contactor is usually placed in the common (minus) battery line for opening the charge and discharge circuits in a case of sealing of the charging or discharging contactors.
255
256 The Main contactor algorithm supports the following modes:
257
258 * Always on;
259 * Automatic.
260
261 In “Always on” mode main contactor closes if all the following is true:
262
263 * Other contactors are open;
264 * There are no errors from the "Errors 1, 2 ..." bitfileds.
265
266 In “Always on” mode main contactor opens if all the following is true:
267
268 * Other contactors are open;
269 * There is an error from the the "Errors 1, 2 ..." bitfileds.
270
271 In “Automatic” mode, the main contactor closes by internal algorithms at the same time with other contactors.
272
273 In “On demand” mode, the main contactor closes by external the “Close Main contactor” request.
274
275 (% class="box infomessage" %)
276 (((
277 **Note: **when errors occur in the system, the **Main **contactor opens either immediately or with the delay T,,off,, (depends on the settings described below).
278 )))
279
280 To change the parameters of the main contactor, select the "Control → Main contactor" section:
281
282 [[image:1740397558976-651.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="144" width="800"]]
283
284 In this section:
285
286 * Enable – a flag to enable the main contactor control;
287 * Algorithm – main contactor control algorithm:
288 ** Always on – contactor is always closed;
289 ** Automatic – contactor closes by internal charge and discharge algorithms;
290 ** On demand – contactor is closed by an external request;
291 * Time to keep the contactor closed before closing the others – a time for other contactors to be open after the main contactor is closed;
292 * Delay before opening the contactor – a time which is used to detect conditions for opening the contactor, s;
293 * Keep the contactor open until the device is restarted – a flag for keeping the main contactor open until the system is reset;
294 * Errors 1, 2 to open the main contactor – bitfields to choose the errors which will open the main contactor.
295
296 *
297
298 === Charge ===
299
300 There are two contactors that serve charging the battery: a charging contactor and an allow charging contactor. With the help of the allow charging contactor, the BMS commands the charger to start or stop charging.
301
302 The device supports three charge control algorithms:
303
304 * charging is always allowed;
305 * charging is allowed when there is a signal “Charger connected”;
306 * charging is allowed when there is a signal “Charge request”.
307
308 If the "**Always on**" algorithm is selected, the charging contactor and the allow charging contactor are always closed. If at least one of the errors appears:
309
310 * Overvoltage;
311 * Overcurrent;
312 * High temperature (CH);
313 * Low temperature (CH);
314 * HYG offline (optional);
315 * Combilift offline (optional);
316 * Spirit offline (optional);
317 * Spirit charger error (optional);
318 * Short circuit (optional);
319 * High contactor temperature (optional);
320 * CH contactor cycles error;
321 * Critical error
322
323 both contactors are open (no current flows).
324
325 When the algorithm "**On Charger connected**" is selected, the control is performed as follows:
326
327 * If there is a signal “Charger connected” and there are no errors (see the list above), then through the delay time T,,on,, the charging contactor and the allow charging contactor close;
328 * If the signal “Charger connected” disappears, the allow charging contactor opens and after the delay time T,,off,, the charging contactor opens;
329 * If in the process of charging the voltage on the cell exceeds the “Ready to charge” level, the allow charging contactor opens (while the charging contactor remains closed);
330 * If errors in the list above occur the charging contactor and allow charging contactor open.
331
332 When the "**On Charge request**" algorithm selected, the control is performed as follows:
333
334 * If there is a signal “Charge request” and there are no errors (see the list above), then through the delay time T,,on,, the charging contactor and the allow charging contactor close;
335 * If the signal “Charge request” disappears, the allow charging contactor opens and after the delay time T,,off,, the charging contactor opens;
336 * If in the process of charging the voltage on the cell exceeds the “Ready to charge” level, the allow charging contactor opens (while the charging contactor remains closed);
337 * If errors in the list above occur the charging contactor and allow charging contactor open.
338
339 (% class="box infomessage" %)
340 (((
341 Note: when errors occur in the system, the **charging **contactor opens either immediately or with the delay T,,off,, (depends on the settings described below).
342 )))
343
344 When the power down request occurs, the allow charging contactor opens immediately and the charging contactor opens after the delay T,,off,,. Reclosing the charging contactor and allow charging contactor is performed if the power down request is removed.
345
346 To change the parameters of the battery charge control algorithm, select the "Control → Charge" section:
347
348 [[image:1733746766516-845.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="319" width="800"]]
349
350 In this section:
351
352 * Enable – a flag to activate the charge control;
353 * Algorithm:
354 ** Always on – charging is always allowed;
355 ** On charger connected – charging is allowed when there is a signal “Charger connected”;
356 ** On charge request – charging is allowed when there is a signal “Charge request”;
357 * Current corresponding to charging – a current level to generate the "Charging current present" signal, A;
358 * Current corresponding to no charging – a current level to clear the "Charging current present" signal, A;
359 * Delay before starting charging – a time delay T,,on,, before closing the charging contactor and the allow charging contactor, millisecond;
360 * Delay before stopping charging – a time delay T,,off,, before opening the charging contactor, millisecond;
361 * Use custom delays before stopping charging (on errors) – a flag to enable manual settings of time delays T,,off,, for specific errors;
362 * Custom delay: <error> – specific error delay, millisecond;
363 * Switch off the charging contactor on errors without delay – a flag to protectively open the charging contactor without a delay. In the opposite case, when an error is detected, the charging contactor opens always with the delay “Delay before stopping charging”;
364 * Control the precharging contactor – a flag that allows control of the precharging contactor;
365 * Voltage to clear the “Ready to charge” – a threshold voltage level on the cell, V; if the voltage of any cell is above this level, the “Ready to charge” (hence, the “Allow charging”) signal is cleared;
366 * Voltage to reset the “Ready to charge” – a tolerant voltage level on the cell, V; if all cell voltages are below the tolerant level, the “Ready to charge” (hence, the “Allow charging”) signal is set;
367 * Delay before recharging – a time after which the previously opened the allow charging contactor closes again, minute; to disable the operation by timeout set "Delay before recharging" to 0.
368
369 (% class="box infomessage" %)
370 (((
371 Note – The allow charging contactor closes under two independent conditions: 1) the voltage on the cells reaches the “Voltage to reset the “Ready to charge"” level and 2) the "Delay before recharging" time has passed since the opening of the allow charging contactor.
372 )))
373
374 === Discharge ===
375
376 The device controls the discharging contactor to connect battery to the load.
377
378 The device supports three algorithms to control battery discharging:
379
380 * load is always connected;
381 * load is connected when there is no signal “Charger connected”;
382 * load is connected when there is signal “Discharge request”.
383
384 When the algorithm "**Always on**" is selected, the discharging contactor is always closed. If at least one of the errors appears:
385
386 * Undervoltage;
387 * Overvoltage (optional);
388 * Overcurrent;
389 * High temperature (DCH);
390 * Low temperature (DCH) (optional);
391 * HYG offline (optional);
392 * Combilift offline (optional);
393 * Spirit offline (optional);
394 * Spirit charger error (optional);
395 * Short circuit (optional);
396 * High contactor temperature (optional);
397 * DCH contactor cycles error;
398 * Critical error
399
400 the discharging contactor opens.
401
402 If the algorithm "**On Charger disconnected**" is selected, the control is performed as follows:
403
404 * if there is no signal “Charger connected”, the charging contactor is opened and there are no errors (see the list above), then through the delay time T,,on,, the discharging contactor closes;
405 * If the signal “Charger connected” appears or errors occur (see the list above), then after the delay time T,,off,, the discharging contactor opens.
406
407 When the "**On Discharge request**" algorithm selected, the control is performed as follows:
408
409 * if there is signal “Discharge request”, the charging contactor is opened and there are no errors (see the list above), then through the delay time T,,on,, the discharging contactor closes;
410 * If the signal “Discharge request” disappears or errors occur (see the list above), then after the delay time T,,off,, the discharging contactor opens.
411
412 (% class="box infomessage" %)
413 (((
414 Note: in case of errors in the system operation, the opening of the **discharging **contactor is performed either immediately or with a delay T,,off,, (depends on the settings described below).
415 )))
416
417 The device supports controlling the precharging contactor. The duration of switching on the precharging contactor before closing the discharging (load) contactor is adjusted.
418
419 When the power down request occurs, the discharging contactor opens after delay T,,off,,. Reclosing the discharging contactor is performed if the power down request is removed.
420
421 To change the parameters of the battery discharge control algorithm, select the "Control → Discharge" section:
422
423 [[image:1733746885414-479.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="319" width="800"]]
424
425 In this section:
426
427 * Enable – a flag to activate the discharge control;
428 * Algorithm:
429 ** Always on – load is always connected;
430 ** On charger disconnected – load is connected when there is no signal “Charger connected”;
431 ** On discharge request – load is connected when there is signal “Discharge request”;
432 * Current corresponding to discharging – a current level to generate the "Discharging current present" signal, А;
433 * Current indicating no discharging – a current level to clear the "Discharging current present" signal, А;
434 * Delay before starting discharging – a time delay T,,on,, before closing the discharging contactor, millisecond;
435 * Delay before stopping discharging – a time delay T,,off,, before opening the discharging contactor, millisecond;
436 * Use custom delays before stopping discharging (on errors) – a flag to enable manual settings of time delays T,,off,, for specific errors;
437 * Custom delay: <error> – specific error delay, millisecond;
438 * Switch off the discharging contactor on errors without delay – a flag to protectively open the discharging contactor without a delay. In the opposite case, when an error is detected, the discharging contactor opens always with the delay “Delay before stopping discharging”.
439 * Precharge time – a duration of closing the precharge contactor before closing the discharging contactor, millisecond;
440 * Voltage to clear the “Ready to discharge” – a threshold voltage level on the cell, V; if the voltage of any cell is below this level, the “Ready to discharge” signal is cleared;
441 * Voltage to reset the “Ready to discharge” – a tolerant voltage level on the cell, V; if all cells voltages are above the tolerant level, the “Ready to discharge” signal is set;
442
443 === Charge/Discharge ===
444
445 The BMS Mini device can control the charging/discharging contactor that is used to both charge and discharge the battery.
446
447 The charging/discharging contactor combines algorithms of charging and discharging contactor. It behaves as a charging contactor when «Charge request» or «Charger connected» are set, otherwise – as a discharging contactor.
448
449 The charging/discharging contactor control is configured in the “Control – Charge/Discharge” section:
450
451 [[image:1733746901779-991.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="95" width="800"]]In this section:
452
453 * Enable – a flag to enable the charge/discharge controller.
454
455 === Discharge (AUX) ===
456
457 The BMS Mini device can control the power supply of external equipment using the auxiliary (AUX) discharging contactor. An example of external equipment can be an inverter that converts DC to AC to power a service laptop and other devices.
458
459 The power supply circuit of the external equipment using the auxiliary (AUX) discharging contactor is independent of the battery load circuit. The closing and opening of the auxiliary (AUX) discharging contactor is performed according to its program.
460
461 If the power supply function of the external equipment is enabled, the auxiliary (AUX) discharging contactor closes. The opening of this contactor occurs on three independent conditions:
462
463 * the battery has low SOC;
464 * the battery voltage is out of range;
465 * the battery system errors are detected.
466
467 To change the parameters of the powering of external equipment, select the "Control → Discharge (AUX)" section:
468
469 [[image:1733746932199-845.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="137" width="800"]]
470
471 In this section:
472
473 * Enable – a flag to activate the auxiliary discharge control;
474 * Switch off the discharging (AUX) contactor if the SOC is too low;
475 * Minimum SOC – a minimum SOC value, when reached, the auxiliary (AUX) discharging contactor opens, %;
476 * Tolerant SOC – a permissive SOC value, upon reaching which the auxiliary (AUX) discharging contactor re-closes, %;
477 * Switch off the discharging (AUX) contactor if the battery voltage is out of the range;
478 * Minimum voltage – minimum battery voltage, V;
479 * Maximum voltage – maximum battery voltage, V;
480 * Switch off the discharging (AUX) contactor on errors – the auxiliary (AUX) discharging contactor opens if the following errors occur: Undervoltage, Overcurrent, High temperature (DCH), Short circuit, Critical error.
481
482 === ===
483
484 === Cell balancing ===
485
486 Balancing makes the voltage of all cells be equal to the minimum cell voltage.
487
488 The following balancing rules are supported:
489
490 * only when the battery is charging (current I > 0) and some time until the battery is relaxed;
491 * when the battery is charging (current I > 0) or when the battery is in a state of relaxation;
492 * always (regardless of battery state).
493
494 A balancing resistor is connected to the cell if:
495
496 * the voltage on the cell is higher than the starting voltage of the balancing;
497 * the difference between the cell voltage and the minimum voltage among the cells of the battery is greater than the balancing deviation.
498
499 (% class="box infomessage" %)
500 (((
501 If the BMS Mini overheats, then the balancing of the cells connected to this device will not be performed.
502 )))
503
504 To change the cell balancing parameters, select the "Control → Cell balancing" section:
505
506 [[image:1733746797003-364.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="104" width="800"]]
507
508 In this section:
509
510 * Enable – a flag to enable cell balancing;
511 * Balancing rule:
512 ** Balance on charge;
513 ** Balance on charge or relaxed;
514 ** Balance always;
515
516 [[image:1733746797004-660.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="104" width="800"]]
517
518 * Minimum cell voltage to start balancing, V;
519 * Balancing deviation, V.
520
521 === Power down ===
522
523 The BMS Mini device can shut down itself if the battery voltage is low or the battery is idle for a long time.
524
525 Shutting down the battery system is performed according to the following conditions:
526
527 * the battery voltage is below the minimum level;
528 * the “Charger connected” signal is cleared for 60 seconds.
529
530 The BMS Mini device also shuts down the battery if it stays in the “Charging OFF”, “Discharging OFF”, “Relaxed (after charging)” or “Relaxed (after discharging)” for the set time.
531
532 To change the parameters of the power down control, select the "Control → Power down" section:
533
534 [[image:1733746797005-459.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="115" width="800"]]
535
536 In this section:
537
538 * Minimum voltage to power down – a minimum voltage level of the battery below which the BMS commands to shut down the battery, V;
539 * Idle time to power down – a time of battery inactivity after which the battery is shut down, minute;
540 * Wait the "Power up/down request" is cleared (on startup) – a flag to enable delay for clearing the “Power up/down request” signal while starting the BMS.
541
542 === Heater ===
543
544 To change the parameters of the heater control algorithm, select the "Control → Heater" section:
545
546 [[image:1733746808496-606.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="116" width="800"]]
547
548 In this section:
549
550 * Enable – a flag to enable heater control;
551 * Minimum cell temperature, °C;
552 * Tolerant cell temperature, °C;
553 * Delay before starting the heater, millisecond;
554 * Delay before stopping the heater, millisecond;
555 * Switch off the heater on errors (Undervoltage, Overcurrent, High temperature, Short circuit or Critical error).
556
557 As a result of operating the heating algorithm, the “Heater” signal is generated.
558
559 Conditions for signal generation:
560
561 * The minimum temperature among all cells of the battery is less than the “Minimum cell temperature” value during the “Delay before starting the heater” time.
562
563 Conditions for clearing the signal:
564
565 * the minimum temperature among all cells of the battery is greater than the “Tolerant cell temperature” value during the “Delay before stopping the heater” time.
566
567 (% class="box infomessage" %)
568 (((
569 If there is the "Heater" signal, the heater contactor closes and/or a signal is output to the corresponded digital output.
570 )))
571
572 === Cooler ===
573
574 To change the parameters of the cooler control algorithm, select the "Control → Cooler" section:
575
576 [[image:1733746808497-424.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="113" width="800"]]
577
578 In this section:
579
580 * Enable – a flag to enable cooler control;
581 * Maximum cell temperature, °C;
582 * Tolerant cell temperature, °C;
583 * Delay before starting the cooler, millisecond;
584 * Delay before stopping the cooler, millisecond;
585 * Switch off the cooler contactor on errors (Undervoltage, Overcurrent, Low temperature, Short circuit or Critical error).
586
587 As a result of operating the cooling algorithm, the "Cooler" signal is generated.
588
589 Conditions for signal generation:
590
591 * the maximum temperature among all cells of the battery is greater than the “Maximum cell temperature” value during the “Delay before starting the cooler” time.
592
593 Conditions for clearing the signal:
594
595 * the maximum temperature among all cells of the battery is less than the “Tolerant cell temperature” value during the “Delay before stopping the cooler” time.
596
597 (% class="box infomessage" %)
598 (((
599 If there is the "Cooler" signal, the cooler contactor closes and/or a signal is output to the corresponded digital output.
600 )))
601
602 === Cell analysis ===
603
604 Discharge characteristics of the battery – the dependence Uocv = Uocv (DOD) – is used to determine the tabular dependence Uocv = Uocv (SOC, t °C), which is necessary for calculating the state of charge of the battery.
605
606 The BMS Mini device can automatically determine the battery discharge characteristic.
607
608 Before starting the process of determining the discharge characteristic, it is necessary to prepare a BMS:
609
610 1. Charge the battery.
611 1. Connect a resistive load to the discharging contactor, which will provide a discharge current of 0.5C (where C is the cell capacitance).
612
613 To configure parameters for determining the discharge characteristic of the battery, select the "Control → Cell analysis" section:
614
615 [[image:1733746808498-116.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="103" width="800"]]
616
617 In this section:
618
619 * Enable – a flag to enable cell analysis;
620 * Discharge step, Ah;
621 * Delta voltage – a maximum allowable voltage drop for the cell, V;
622 * Cell index – a position of the analyzed cell;
623 * Analyse the most discharged cell – a flag to analyse of the least charged cell (in this case, the value “Cell index” is ignored).
624
625 Discharge step should be set equal to
626
627 Discharge step= С/21,
628
629 where C is the cell capacity.
630
631 The discharge characteristic will be constructed for the given cell (its position is determined by the field “Cell index”).
632
633 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 contactor is performed by this algorithm.
634
635 Algorithm steps:
636
637 1. DOD = 0.
638 1. Opening the discharging contactor.
639 1. Waiting for the relaxation of the battery.
640 1. Measuring Uocv = U.
641 1. Saving the point of the discharge characteristic (Q, U,,OCV,,).
642 1. Closing of the discharging contactor. DOD,,1,, = DOD + Discharge step, U,,1,, = U
643 1. If DOD = DOD,,1,, or U < (U,,1,, – Delta voltage), then go to step 2.
644 1. If the "Undervoltage" error is detected, then the end of the algorithm.
645
646 During the operation of the algorithm, a file with the name "CELLANALYSIS.TXT" in the CSV format will be created on the SD card.
647
648 File structure:
649
650 |**Time**|**DOD**|**Cell**|**OCV**|**Resistance**
651 |**10.11.2017 12:28:34**|0.0|1|4.180|0.080000
652 |**...**|...|…|...|...
653
654 Parameter names:
655
656 * Time – date and time;
657 * DOD – depth of discharge, Ah;
658 * Cell – position of the analyzed cell for which OCV and Resistance values are provided;
659 * OCV – cell voltage Uocv, V;
660 * Resistance – cell resistance, Ohm.