Abstract
The application of photovoltaics (PV) has been increasingly popular, especially in remote areas where power from a utility is not available or is too costly to install. PV powered water pumping is frequently used for agriculture and in households. Among many available schemes, the system under study consists of a PV array, a variable-frequency inverter, an induction motor, and a water pump. Theinverter feeds the induction motor, which drives the water pump. To seek the optimum power output of the PV array, the inverter is operated at variable frequency to vary the output of the water pump. The inverter is operated to generate a six-step quasi-square wave instead of a pulse width modulated (PWM) voltage output to reduce the switching losses. The inverter acts as both avariable-frequency source and a peak-power tracker of the system, thus having the number of switches minimized. The system is a low-cost design with a simple control strategy. The direct current (DC) bus is supported by a DC capacitor; thus, a balance-of-power flow must be maintained to avoid the collapse of the DC bus voltage. Another advantage of the system is that the current is limited to anupper limit of the PV array current. Thus, in case a short circuit is developed, the motor winding and the power semiconductor switches can be protected against excessive current flow.
Original language | American English |
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Pages | 133-142 |
Number of pages | 10 |
State | Published - 1997 |
Event | IAS '96: 1996 IEEE Industry Applications Conference, Thirty-First IAS Annual Meeting - San Diego, California Duration: 6 Oct 1996 → 10 Oct 1996 |
Conference
Conference | IAS '96: 1996 IEEE Industry Applications Conference, Thirty-First IAS Annual Meeting |
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City | San Diego, California |
Period | 6/10/96 → 10/10/96 |
NREL Publication Number
- NREL/CP-500-23047