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Changes for page 3.4 Battery parameters

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1 -Battery management systems.BMS Main 2\.1.3\. Configuration.WebHome
1 +drafts.BMS Main 2\.1.3\. Configuration.WebHome
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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 -= Configuration =
1 +== 3.4.1 Cell defaults ==
3 3  
4 -(% data-numbered-headings-start="4" style="--numbered-headings-start: 3;font-size: 0px;color: rgba(0, 0, 0, 0.0);margin-bottom: 0px; margin-top: 0px;" %)
5 -== Battery parameters ==
6 -
7 -=== Cell defaults ===
8 -
9 9  To change the default cell settings, select the menu "Cells → Cell defaults":
10 10  
11 11  [[image:1732205873121-893.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="281" width="374"]]
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26 26  
27 27  The “Reset cell parameters” command is used for starting-up and adjustment of battery.
28 28  
29 -=== SOC estimation ===
23 +== 3.4.2 SOC estimation ==
30 30  
31 31  The BMS Main 2.x board calculates the state of charge of the battery (SOC) using two algorithms:
32 32  
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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;
53 53  * Scale the final SOC – flag to scale the battery SOC by the following values;
54 54  * Internal SOC corresponding to 0% – battery SOC that sets to be 0%;
55 55  * Internal SOC corresponding to 100% – battery SOC that sets to be 100%.
56 -* Uocv = Uocv(SOC, t °C) – the dependence of the cell open circuit voltage Uocv on SOC and the cell temperature (selected for specific batteries, can be established experimentally – see [[Cell analysis>>doc:||anchor="HCellanalysis"]]);
48 +* Uocv = Uocv(SOC, t °C) – the dependence of the cell open circuit voltage Uocv on SOC and the cell temperature (selected for specific batteries, can be established experimentally – see [[3.4.6 Cell analysis>>doc:||anchor="H3.4.6Cellanalysis"]]);
57 57  * Linear zone – linear zone of dependence Uocv = Uocv(SOC, t °C):
58 58  ** Uocv ,,[point 1],, – starting point of the linear zone;
59 59  ** Uocv ,,[point 2],, – end point of the linear zone;
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69 69  
70 70  The SOC calculation algorithm “Current and voltage (enhanced)” 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).
71 71  
72 -=== Cell resistance estimation ===
64 +== 3.4.3 Cell resistance estimation ==
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 -{{formula fontSize="SMALL" imageType="PNG"}}
77 -R = \frac{U-U_{ocv}}{I_{stable}}
78 -{{/formula}}
68 +R = (U-Uocv) / Istable,
79 79  
80 80  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.
81 81  
82 82  The second method is used for a stepwise change in the current through the cell, while the value of the cell resistance:
83 83  
84 -{{formula fontSize="SMALL"}}
85 -R = \frac{U_2-U_1}{I_{stable2}-I_{stable1}}
86 -{{/formula}}
74 +R = (U,,2,,-U,,1,,) / (I,,stable2,,-I,,stable1,,) provided that | I,,stable2,,-I,,stable1,, | > 0.2 × Q,,max,,
87 87  
88 -provided that
76 +(Q,,max,, is the maximum cell capacity),
89 89  
90 -{{formula fontSize="SMALL"}}
91 -| I_{stable2}-I_{stable1} | > 0.2 × Qmax
92 -{{/formula}}
78 +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 93  
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 -
96 96  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.
97 97  
98 98  To change parameters of the algorithm for calculating the cell resistance, select the menu "Cells → Cell resistance estimation":
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107 107  * Minimum SOC – minimum cell SOC value for resistance calculation;
108 108  * Maximum SOC – maximum cell SOC value for resistance calculation.
109 109  
110 -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 [[Cell defaults>>doc:||anchor="HCelldefaults"]]). 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).
94 +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 [[3.4.1 Cell defaults>>doc:||anchor="H3.4.1Celldefaults"]]). 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).
111 111  
112 -=== Cell balancing ===
96 +== 3.4.4 Cell balancing ==
113 113  
114 114  The BMS Main 2.x supports two cell balancing algorithms:
115 115  
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131 131  * the voltage on the cell is higher than the starting voltage of the balancing;
132 132  * the difference between the cell voltage and the minimum voltage among the cells of the battery is greater than the balancing threshold.
133 133  
134 -A balancing resistor is disconnected from the cell if any of the following conditions are met:
118 +If the BMS Logic board overheats, then the balancing of the cells connected to this board will not be performed (see [[3.6.18 Logic high temperature protection>>doc:drafts.BMS Main 2\.1.3\. Configuration.3\.6 Battery protection.WebHome||anchor="H3.6.18Logichightemperatureprotection"]]).
135 135  
136 -* the voltage on the cell is less than the balancing stop voltage;
137 -* the difference between the voltage on the cell and the minimum voltage among the battery cells is less than the balancing stop threshold.
138 -
139 -If the BMS Logic board overheats, then the balancing of the cells connected to this board will not be performed (see [[Logic high temperature protection>>doc:Battery management systems.BMS Main 2\.1.3\. Configuration.3\.6 Battery protection.WebHome||anchor="HLogichightemperatureprotection"]]).
140 -
141 -The BMS Main 2.1 can enable the cell balancing by the external “Balancing request” signal. Balancing process will be started to cells which the voltage is higher than the balancing start voltage and the difference between the cell voltage and the minimum voltage among all the cells is greater than the balancing stop threshold.
142 -
143 -BMS Main 2.1 can force a cell balancing, if its voltage is higher than estimated value.
144 -
145 145  To change the cell balancing parameters, select the menu "Cell → Cell balancing":
146 146  
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"]]
122 +[[image:1732207485773-804.png||data-xwiki-image-style-alignment="center" data-xwiki-image-style-border="true" height="264" width="387"]]
148 148  
149 149  In this section:
150 150  
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156 156  ** Charging;
157 157  ** Charging or relaxed;
158 158  ** 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;
162 162  * Minimum cell voltage to start balancing, 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;
135 +* Balancing threshold, V;
166 166  * Start cell discharging – a command to start forced balancing of all battery cells (used for service purposes);
167 167  * Stop cell discharging – a command to stop forced balancing of all battery cells (used for service purposes).
168 168  
169 -=== Series balancing ===
139 +== 3.4.5 Series balancing ==
170 170  
171 171  The BMS Main 2.x board supports work with two independent (galvanically unrelated) cell series. To monitor the status of two series, two current sensors are used: primary and secondary (AUX). A series of cells must be equivalent: they must have the same number of cells and the same capacity.
172 172  
173 -Since the series of cells can operate at different loads, they must be balanced. For this, the BMS Main 2.x provides two relays: “Balancing series 1” and “Balancing series 2” (see [[Input and output signals>>doc:Battery management systems.BMS Main 2\.1.3\. Configuration.3\.3 Input and output signals.WebHome]]), as well as a combined algorithm that considers both the voltage of each series and the charge that these series gave load. “Balancing series 1” and “Balancing series 2” relays are used to connect high-power balancing resistors in parallel with cells series 1 and 2.
143 +Since the series of cells can operate at different loads, they must be balanced. For this, the BMS Main 2.x provides two relays: “Balancing series 1” and “Balancing series 2” (see [[3.3 Input and output signals>>doc:drafts.BMS Main 2\.1.3\. Configuration.3\.3 Input and output signals.WebHome]]), as well as a combined algorithm that considers both the voltage of each series and the charge that these series gave load. “Balancing series 1” and “Balancing series 2” relays are used to connect high-power balancing resistors in parallel with cells series 1 and 2.
174 174  
175 175  When charging the battery, balancing is performed based on the voltage of the series. A balancing resistor is connected to the cell series if:
176 176  
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192 192  * Coulomb threshold – the difference of the charges Qthr, given by a series of cells, above which balancing to be started, Ah;
193 193  * Period – period to reset of charge counters for each series (to avoid accumulation of error), second.
194 194  
195 -=== Cell analysis ===
165 +== 3.4.6 Cell analysis ==
196 196  
197 -Discharge characteristics of the battery – the dependence Uocv = Uocv (DOD) – is used to determine the tabular dependence Uocv = Uocv (SOC, t °C) (see [[SOC estimation>>doc:||anchor="HSOCestimation"]]), which is necessary for calculating the state of charge of the battery.
167 +Discharge characteristics of the battery – the dependence Uocv = Uocv (DOD) – is used to determine the tabular dependence Uocv = Uocv (SOC, t °C) (see [[3.4.2 SOC estimation>>doc:||anchor="H3.4.2SOCestimation"]]), which is necessary for calculating the state of charge of the battery.
198 198  
199 199  The BMS Main 2.x board can automatically determine the battery discharge characteristic.
200 200  
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255 255  * OCV – cell voltage Uocv, V;
256 256  * Resistance – cell resistance, Ohm.
257 257  
258 -=== Charge current map ===
228 +== 3.4.7 Charge current map ==
259 259  
260 260  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.
261 261  
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278 278  
279 279  Charging current limit = Maximum charging current × Kcs × Kcc × Kcv × Kct.
280 280  
281 -=== Discharge current map ===
251 +== 3.4.8 Discharge current map ==
282 282  
283 283  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.
284 284  
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302 302  
303 303  Discharging current limit = Maximum discharging current × Kds × Kdc × Kdv × Kdt.
304 304  
305 -=== SOC correction ===
275 +== 3.4.9 SOC correction ==
306 306  
307 -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 [[SOC estimation>>doc:||anchor="HSOCestimation"]]).
277 +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 [[3.4.2 SOC estimation>>doc:||anchor="H3.4.2SOCestimation"]]).
308 308  
309 309  To configure parameters for periodically correcting the battery state of charge, select the menu "Cells → SOC correction":
310 310  
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