Evaluation of two prototype three phase photovoltaic water pumping systems

Two prototype three phase AC photovoltaic pump systems (Solvo, ML T) and a DC PV pump (Miltek) were tested on a farm borehole in Namibia (latitude 21°6', longitude 17°6'). The PV array consisted of twelve modules (636Wpeak) mounted on a single-axis passive tracker. The depth of the water was 75m and a progressive cavity pump with a self-compensating stator was used in all the tests. Customised data acquisition was designed to measure performance characteristics through a range of operating conditions (mainly steady state); a secondary data acquisition system was used to capture samples of high frequency signals. The data allowed detailed analysis of system, subsystem and component performance, as well as performance evaluation over Standard Solar Days. The focus of the investigation was evaluation of the AC prototypes, in terms of performance, other technical factors, reliability and economic criteria. The analog-based DC system served as a basis for comparison. Both AC systems employed microprocessor control and PWM variable-frequency variable-voltage inversion. Efficiencies, optimality, stability, start-up behaviour, non-productive operating modes and protection were examined. A number of recommendations were proposed for improvements in the basic control algorithms, monitoring and managing non-productive modes, improved protection, layout and user diagnostic features.

Grantor dc:publisher.institution

Energy Research Centre

Year dc:date.issued

1994

Author dc:creator

• Scholle, Axel

Advisors dc:contributor.advisor

• Cowan, Bill
• Greene, John

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/9626

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/9626