serial vs. parallel connections. serial connections serial connections are positive-to-negative in a...
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Serial vs. Parallel Connections
Serial Connections• Serial connections are positive-to-negative
in a chain
Serial Connections – PV’s
• Voltages add– Higher voltage and lower current reduce
losses in wiring– Can exceed voltage capacity of charge
controller
• Reduces number of cables to combiner
• Current is the same through each device
Serial Connections – PV’s
48 volts
5 amps
An MPPT controller can take the 5 amps * 48 volts = 240 watts and charge a 24 volt battery with 10 amps (neglecting losses)
Parallel Connections• Parallel connections are
positive-to-positive and negative-to-negative
12 v
PV
5 A+ -
12 v
PV
5 A+ -
10 Abreaker
10 Abreaker
Parallel Connections – PV’s
• Voltage is the same across each panel
• Increases number of cables to combiner if multiple panel arrays are used
• An MPPT controller uses the actual array voltage
• A PWM controller sets PVs at battery voltage
• Current adds
Parallel Connections
12 v
PV
5 A+ -
12 v
PV
5 A+ -
10 Abreaker
10 Abreaker
12 volts
10 amps
Serial/Parallel Connections – Batteries
• Batteries must be identical
+ -12 v220 amp-hour
+ -12 v220 amp-hour
+ -12 v220 amp-hour
+ -12 v220 amp-hour
Serial orParallel ?
Serial orParallel ?
Volts?
Volts?
Amp-hours?
Amp-hours?
Serial/Parallel Connections – Batteries
• Batteries must be identical
+ -12 v220 amp-hour
+ -12 v220 amp-hour
+ -12 v220 amp-hour
+ -12 v220 amp-hour
Parallel
Serial
12 Volts
24 Volts
440 Amp-hours
220 Amp-hours
Serial Connections – Loads
• Current is the same through all loads– This is the current the source must provide
• Voltage drops between loads add• Voltage available for the next load in series is
reduced by the previous load• Failure of any load results in failure of all
Serial Connections – Loads
Current is the same through each load. If the total of all voltage requirements of all loads is greater than the voltage supplied some will have low voltage and may be damaged.
Parallel Connections – Loads
• Total current usage adds• Same voltage is available at each load• Failure of one load may not affect the others• Loads with mixed current requirements are not
affected (as long as the total current needed does not exceed system capacity).
Parallel Connections – Loads
•This configuration depicts multiple loads wired in parallel.•Each load is rated for the battery voltage. •The total current from the battery is the sum of the current through each load,
•even though each load pulls a different current
?’s