SolarLader/SolarLader_Firmware
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Some MPP tuning

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This commit is contained in:
Thomas Kolb 2016-09-03 16:02:34 +02:00
parent 11d0878864
commit 8ed36f6770
1 changed files with 38 additions and 11 deletions
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43
src/main.c
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@ -380,10 +380,13 @@ struct MPPState {
int32_t mppMaxPWM; int32_t mppMaxPWM;
}; };
#define MPP_TEST_DURATION 10 /* ms */ #define MPP_TEST_IGNORE_DURATION 5 /* ms */
#define MPP_TEST_ACCU_DURATION 20 /* ms */
#define MPP_TEST_STEPS 4 #define MPP_TEST_DURATION (MPP_TEST_IGNORE_DURATION + MPP_TEST_ACCU_DURATION)
const int32_t mpp_pwm_offsets[MPP_TEST_STEPS] = {-3, 4, -21, 20};
#define MPP_TEST_STEPS 6
const int32_t mpp_pwm_offsets[MPP_TEST_STEPS] = {-3, 4, -16, 15};
static void mpp_run( static void mpp_run(
uint32_t time_in_state, struct MPPState *mpp_state, uint32_t time_in_state, struct MPPState *mpp_state,
@ -410,14 +413,33 @@ static void mpp_run(
/* test running */ /* test running */
/* accumulation */ /* accumulation */
if(time_in_state > (mpp_state->nextTestStepTime - MPP_TEST_ACCU_DURATION)) {
mpp_state->powerAccu = fxp_add(mpp_state->powerAccu, mpp_state->powerAccu = fxp_add(mpp_state->powerAccu,
fxp_mult(power_state->vout, power_state->current)); fxp_mult(power_state->vout, power_state->current));
mpp_state->powerSamples++; mpp_state->powerSamples++;
}
if(time_in_state > mpp_state->nextTestStepTime) { if(time_in_state > mpp_state->nextTestStepTime) {
/* averaging */ /* averaging */
mpp_state->powerAccu = fxp_div(mpp_state->powerAccu, fxp_from_int(mpp_state->powerSamples)); mpp_state->powerAccu = fxp_div(mpp_state->powerAccu, fxp_from_int(mpp_state->powerSamples));
#ifdef DEBUG
char msg[16];
debug_send_string("Accu: ");
fxp_format(mpp_state->powerAccu, msg, 3);
debug_send_string(msg);
debug_send_string(" ");
fxp_format_int(mpp_state->powerSamples, msg);
debug_send_string(msg);
debug_send_string(" PWM: ");
fxp_format_int(*pwm, msg);
debug_send_string(msg);
debug_send_string(" Idx: ");
fxp_format_int(mpp_state->testIdx, msg);
debug_send_string(msg);
debug_send_string("\r\n");
#endif
if(mpp_state->powerAccu > mpp_state->maxPower) { if(mpp_state->powerAccu > mpp_state->maxPower) {
mpp_state->maxPower = mpp_state->powerAccu; mpp_state->maxPower = mpp_state->powerAccu;
mpp_state->maxPWM = *pwm; mpp_state->maxPWM = *pwm;
@ -439,18 +461,19 @@ static void mpp_run(
} else if(mpp_state->testIdx == MPP_TEST_STEPS) { } else if(mpp_state->testIdx == MPP_TEST_STEPS) {
/* finalize test */ /* finalize test */
if(mpp_state->maxPower > mpp_state->refPower) { if(mpp_state->maxPower > mpp_state->refPower) {
/* better PWM value found -> initiate new test to reach MPP */
mpp_state->testIdx = -1;
mpp_state->refPower = mpp_state->maxPower; mpp_state->refPower = mpp_state->maxPower;
*pwm = mpp_state->maxPWM; *pwm = mpp_state->maxPWM;
/* test again after a short time */
mpp_state->testIdx++;
mpp_state->nextTestStepTime = time_in_state + 250;
} else { } else {
/* We were already at the maximum power point */ /* We were already at the maximum power point */
*pwm = mpp_state->refPWM; *pwm = mpp_state->refPWM;
/* test again after some time */ /* test again after some time */
mpp_state->testIdx++; mpp_state->testIdx++;
mpp_state->nextTestStepTime = time_in_state + 5000; mpp_state->nextTestStepTime = time_in_state + 20000;
} }
} else { } else {
/* no test active, just holding PWM */ /* no test active, just holding PWM */
@ -526,7 +549,7 @@ int main(void)
fxp_t VOUT_SCALE = fxp_from_float(12.6f / 1620.0f); fxp_t VOUT_SCALE = fxp_from_float(12.6f / 1620.0f);
fxp_t CURRENT_SCALE = fxp_from_float(9.01f / 4095.0f); fxp_t CURRENT_SCALE = fxp_from_float(9.01f / 4095.0f);
fxp_t CURRENT_OFFSET = fxp_from_float(0.049); fxp_t CURRENT_OFFSET = fxp_from_float(0.045);
/* if power changes by more than this factor, MPP is tested again */ /* if power changes by more than this factor, MPP is tested again */
MPP_MAX_POWER_CHANGE_FACTOR = fxp_from_float(0.2f); MPP_MAX_POWER_CHANGE_FACTOR = fxp_from_float(0.2f);
@ -747,6 +770,8 @@ int main(void)
// limit has gone too low -> retry at maximum // limit has gone too low -> retry at maximum
mpp_state.mppMaxPWM = CONV_PWM_MAX; mpp_state.mppMaxPWM = CONV_PWM_MAX;
} }
pwm = mpp_state.mppMaxPWM;
} }
if(power_state.vout_avg > MAX_VOLTAGE) { if(power_state.vout_avg > MAX_VOLTAGE) {
@ -797,7 +822,9 @@ int main(void)
lcd_send_string(") "); lcd_send_string(") ");
while(lcd_process() == 0); // send everything immediately while(lcd_process() == 0); // send everything immediately
#ifndef DEBUG
deepsleep(sleep_time); deepsleep(sleep_time);
#endif
// Woke up again. // Woke up again.
lcd_set_cursor_pos(0, 0); lcd_set_cursor_pos(0, 0);