Method and arrangement for controlling a solar powered pump

Abstract

A method and arrangement are disclosed for operating a pump in pump system having a photovoltaic panel system, an inverter electrically connected to the photovoltaic panel system, and a motor driving the pump and electrically connected to the output of the inverter. The method can include setting a voltage limit for the inverter, monitoring the voltage produced by the photovoltaic panel system, operating the inverter for rotating of the motor when the voltage produced by the photovoltaic panel system is above the voltage limit, and disabling use of the inverter when the voltage of the photovoltaic system remains below the voltage limit.

1 . A method of operating a pump in a pump system having a photovoltaic panel system, an inverter electrically connected to the photovoltaic panel system, and a motor driving the pump and electrically connected to an output of the inverter, the method comprising:
 setting a voltage limit for the inverter;   monitoring voltage produced by the photovoltaic panel system;   operating the inverter for rotating of the motor when the voltage produced by the photovoltaic panel system is above the voltage limit; and   disabling use of the inverter when the voltage of the photovoltaic system is below the voltage limit.   
     
     
         2 . A method according to  claim 1 , comprising:
 setting a rotational speed limit;   monitoring a rotational speed of the motor connected to the output of the inverter; and   disabling the use of the inverter when the rotational speed of the motor is below the set rotational speed limit.   
     
     
         3 . A method according to  claim 2 , comprising:
 restarting of the inverter by checking whether the monitored voltage is above the set voltage limit;   starting operation of the inverter if the voltage is above the set limit; and   if the inverter is disabled due to dry run fault or due to low rotational speed, then starting the operation of the inverter after a settable time delay.   
     
     
         4 . A pump arrangement comprising:
 a photovoltaic panel system;   an inverter electrically connected to the photovoltaic panel system;   a motor driving a pump and electrically connected to an output of the inverter;   means for setting a voltage limit for the inverter;   means for monitoring voltage produced by the photovoltaic panel system such that the inverter will be controlled to operate for rotating the motor when a voltage produced by the photovoltaic panel system is above the voltage limit; and   means for disabling use of the inverter when a voltage produced by the photovoltaic system is below the voltage limit.