Universal Photovoltaic Management System (UPMS) 3-kVA and 15-kVA Stand-alone Hybrid PV plantsrop

Duration: 1997 – 2000 ● Client: Joule III ● WIP Role: Research and Innovation

The principal aim of this project was to develop two prototypes of a Universal Photovoltaic Management System (UPMS) based on two selected standard sizes of stand-alone applications. The basic aims were to achieve significant cost reduction and reliability improvements over previous balance of system (BOS) configurations. R.E.S.P.E.C.T. Engineering and ATERSA are developing and building the prototypes with a standard ac output rating of 3 kVA and 15 kVA in cooperation and with the support of WIP.

The two basic types of Universal PV Management System are briefly described below.

Low-power UPMS prototype, 3kVA

This unit is a modular standardized size to be used in low-power hybrid PV power plant, installed near the user's or owner's residence, with a standard ac power output rating of 3 kVA, PV array is rated at 1.5 kWp, and the battery capacity is rated at 750 Ah. The system voltage is 24Vdc. All power electronics, power distribution switching and protective devices, monitoring capability, and energy management systems are completely packaged inside one container. The power sources, one solar irradiance sensor, the battery storage system and the residential loads are the only connections to this UPMS. The first prototype has been installed, tested and monitored in the PV plant of the test facility of RESPECT in Argos, Greece. The performance ratio during the monitoring phase was 46.2% and the max. matching factor of 45.3%. The max. inverter efficiency was 91% at partial loads.

High-power UPMS prototype, 15kVA

This is also modularized and standardized but designed for use in larger power applications such as centralized village power sources. Standard ratings selected are ac power output rating of 15 kVA, PV array sized up to 10kW, and battery capacity of 1,200 Ah. The dc bus voltage of the system is 120Vdc. The UPMS components were implemented in a compact container, one side the ”power zone” and on the other side the ”control zone”. The power sources, the battery storage system, and the exits for the loads will be connected at the back side of the container. The prototype unit has been installed, checked out and monitored in a PV hybrid plant in Gran Canaria, Spain. The performance ratio achieved during the monitoring phase was 40.4% and the inverter efficiency was 92 % at partial loads.

The development of the universal PV management systems resulted in considerable reduced costs in comparison with conventional configurations due to the compact design. Both units are faster to install, and the simplicity of testing, initial check-out and maintenance will reduce labour costs.

The project development addresses basic R&D and major hardware development efforts while providing a high industrial relevance for the project results. The project results is used by all three partners to market the UPMS units.