70 lines
2.1 KiB
C
70 lines
2.1 KiB
C
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#include "SoC_Estimation.h"
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#include "CAN_Communication.h"
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#include "SPI_Communication.h"
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#include "util.h"
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#include <stdint.h>
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uint8_t current_soc = 0;
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static const float internal_resistance_curve_x[] = {2.0, 4.12};
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static const float internal_resistance_curve_y[] = {0.0528, 0.0294};
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#define INTERNAL_RESISTANCE_CURVE_PTS \
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(sizeof(internal_resistance_curve_x) / sizeof(*internal_resistance_curve_x))
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static const float soc_ocv_x[] = {2.1, 2.9, 3.2, 3.3, 3.4,
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3.5, 3.68, 4.0, 4.15, 4.2};
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static const float soc_ocv_y[] = {0, 0.023, 0.06, 0.08, 0.119,
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0.227, 0.541, 0.856, 0.985, 1.0};
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#define SOC_OCV_PTS (sizeof(soc_ocv_x) / sizeof(*soc_ocv_x))
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static int start_soc_known = 0;
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static float start_soc;
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static float start_as;
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static float min_cell_voltage;
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static void estimate_start_soc_off();
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static void estimate_start_soc_on();
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void estimate_soc() {
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uint16_t min_v = 0xFFFF;
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for (int slave = 0; slave < NUMBEROFSLAVES; slave++) {
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for (int cell = 0; cell < N_CELLS_SERIES; cell++) {
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uint16_t v = slaves[slave].cellVoltages[cell];
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if (v < min_v) {
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min_v = v;
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}
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}
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}
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min_cell_voltage = min_v * CELL_VOLTAGE_CONVERSION_FACTOR;
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if (shuntcurrent < SOCE_SHUNT_CURRENT_OFF_THRESH) {
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estimate_start_soc_off();
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} else if (!start_soc_known) {
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estimate_start_soc_on();
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}
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float soc = start_soc - (shuntampereseconds - start_as) / BATTERY_CAPACITY;
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current_soc = soc * 255;
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}
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static void estimate_start_soc_on() {
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float r_i = interp(INTERNAL_RESISTANCE_CURVE_PTS, internal_resistance_curve_x,
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internal_resistance_curve_y, min_cell_voltage);
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float i = shuntcurrent / N_CELLS_PARALLEL;
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float ocv = min_cell_voltage - i * r_i;
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start_soc = calculate_soc_for_ocv(ocv);
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start_as = shuntampereseconds;
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start_soc_known = 1;
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}
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static void estimate_start_soc_off() {
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start_soc = calculate_soc_for_ocv(min_cell_voltage);
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start_as = shuntampereseconds;
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start_soc_known = 1;
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}
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float calculate_soc_for_ocv(float ocv) {
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return interp(SOC_OCV_PTS, soc_ocv_x, soc_ocv_y, ocv);
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}
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