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electrical:solar:charge_controller [2022/04/30 17:03]
frater_secessus [shunt] |
electrical:solar:charge_controller [2022/04/30 17:20]
frater_secessus [specs] |
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| * **rating (or "size")** - this is usually the maximum output the controller can produce (charging + loads).((for technical reasons with PWM this will also be the *input* current limit)) | * **rating (or "size")** - this is usually the maximum output the controller can produce (charging + loads).((for technical reasons with PWM this will also be the *input* current limit)) |
| * **Maximum input voltage** - the highest voltage the controller should ever see from the solar array.((it is common to leave ~20% margin)) | |
| * **12v/24v/48v** - this refers to the nominal voltage of the battery bank it will be charging. | * **12v/24v/48v** - this refers to the nominal voltage of the battery bank it will be charging. |
| | * **Maximum input voltage** - the highest voltage the controller should //ever// see from the solar array.((it is common to leave ~20% margin)) NOTE: a 50v input max does //not// mean a PWM controller can make efficient use of a 24v panel / 12v battery combination. See how to choose below. |
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| There are some considerations when [[electrical:solar:mppt design|designing a system around an MPPT controller]]. | There are some considerations when [[electrical:solar:mppt design|designing a system around an MPPT controller]]. |
| ==== shunt ==== | ==== shunt ==== |
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| | see article below |
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| | ==== single-stage chargers ==== |
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| [[http://amzn.to/2yQppTX|{{ https://images-na.ssl-images-amazon.com/images/I/41Gwyw0BT5L._AC_US160_.jpg}}]] | [[http://amzn.to/2yQppTX|{{ https://images-na.ssl-images-amazon.com/images/I/41Gwyw0BT5L._AC_US160_.jpg}}]] |
| In this usage, //shunt controllers// are single-stage chargers that hold the bank at a [[electrical:solar:charge_controller_setpoints|setpoint]] (Vdisconnect)((whether generally or exactly)) as long as sufficient solar harvest is present. When the setpoint voltage is achieved the controller is turned off for some amount of time.((In a hydro or windpower scenario the power cannot be turned off and is diverted (shunted) instead to a diversion load like water heating, water pumping, etc.)) | Single-stage chargers hold the bank at a [[electrical:solar:charge_controller_setpoints|setpoint]] (Vdisconnect)((whether generally or exactly)) as long as sufficient solar harvest is present. When the setpoint voltage is achieved the controller current is turned off for some amount of time.((In a hydro or windpower scenario the power cannot be turned off and is diverted (shunted) instead to a diversion load like water heating, water pumping, etc.)) There are several different ways of turning off the current: |
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| Technical note: //shunts// short out the panels to control ON/OFF charging. //Series chargers// behave similarly but open-circuit the panels. //PWM// is like a superfast series charger whose ON/OFF cycles are so fast that an average voltage can be held.((it actually does it by varying the width of the ON periods, resulting in a percentage of ON time)) | * PWM - open circuit the panels very rapidly (tens-to-thousands times a second)and for varying lengths of time to hold the voltage setpoint more precisely. Same as PWM controllers above, but in this market range the modulation tends to be cruder/slower and there is only one charging voltage setpoint. |
| | * shunt - shorts the panels ON/OFF (charge-and-stop, less common) |
| | * series - open circuits the panels ON/OFF (charge-and-stop, less common) |
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| Simple versions use simple electronics((as with [[https://www.flexcharge.com|Flexcharge]])) or relays to turn charging on until Vdisconnect is reached, at which point charging is turned off off. If/when voltage falls to some lower voltage (Vreconnect) charging begins again. This is sometimes called [[electrical:12v:charging#charge-and-stop|charge and stop charging]] or on/off charging. Voltage tends to wander a bit as the charging stops and starts. They are often used where extreme simplicity/robustness is required, or where more complex electronics might cause electrical interference.((as in a ham shack)) | Simple versions use simple electronics((as with [[https://www.flexcharge.com|Flexcharge]])) or relays to turn charging on until Vdisconnect is reached, at which point charging is turned off off. If/when voltage falls to some lower voltage (Vreconnect) charging begins again. This is sometimes called [[electrical:12v:charging#charge-and-stop|charge and stop charging]] or on/off charging. Voltage tends to wander a bit as the charging stops and starts. They are often used where extreme simplicity/robustness is required, or where more complex electronics might cause electrical interference.((as in a ham shack)) |
