Photovoltaic System Commissioning, Maintenance & Troubleshooting PDF

AEEP4111 Renewable Energy Conversion II L8 Commissioning, testing and troubleshooting of photovoltaic systems Faizan Rashid [email protected] Topi cs  Introduction to Grid connected PV systems  Grid requirements, codes, and safety Standards  Design of a...

AEEP4111 Renewable Energy Conversion II L8 Commissioning, testing and troubleshooting of photovoltaic systems Faizan Rashid [email protected] Topi cs  Introduction to Grid connected PV systems  Grid requirements, codes, and safety Standards  Design of a Grid-Connected PV Systems  Battery-Backup PV systems  Grid-connected PV systems sizing  Commissioning, testing and troubleshooting of photovoltaic systems  Economic Considerations of PV systems  Grid-connected wind energy systems.  Impact of renewable energy sources (PV, Wind) on electric grid Commissioning  It is the process of testing a PV system to confirm that it is producing electricity and interacting correctly with the electricity grid.  Before an installer leaves the system to the customer, it should be tested and inspected to ensure that the system is compliant with national and local standards and regulations, that all components have been safely installed and that all components are functioning as expected.  Many utilities have rules or procedures that must be followed during the system commissioning process and in some cases the utility may wish to conduct a commissioning inspection. Inspection  Before the PV system is commissioned, an inspection should happen to ensure the system is ready to be tested.  If any issues are identified they should be addressed before switching on  The equipment and installation should be checked to ensure that:  Equipment and components are not damaged.  The system matches the design documents and all equipment has been correctly connected according to the wiring diagrams.  Equipment and components comply with local safety standards Inspect ion Examples: This is an example for a checklist that the inspector should go through before starting the commissioning process Inspect ion Examples: This is an example for a checklist that the inspector should go through before starting the commissioning process  Testi ng Following a visual inspection of the system, testing should be undertaken in accordance with the prevailing national codes.  National codes may require installers to ensure that the following points are compliant prior to system testing:  There is no voltage at the output of the PV array (and at the output of each string if there is more than one). This may be achieved by leaving one of the module’s interconnects disconnected/unplugged.  Any fuses have been removed and all circuit breakers are in the ‘off’ position.  The AC and DC main disconnects/isolators are in the ‘off’ position; local codes may also require them to be tagged or locked  Testi ng After the safety requirements outlined in the local codes have been fulfilled, testing may be undertaken.  Each component is switched on and each isolator closed individually, beginning at the array and ending at the loads (i.e. appliances).  Testing is done in this order for safety; it reduces the risk of hazards and equipment damage should any problems  Testi ng At each step the system is tested by measuring the system parameters using meters and the displays on various components (i.e. the inverter display will show important data about the system).  If at any stage the system begins to operate outside the expected parameters then electricians must identify the problem and address it before testing can continue.  The testing person will be looking for specific parameters and values.  Testi ng Common parameters that are tested include:  continuity between adjacent system components;  resistance of cable insulation;  measurement of array and string open-circuit voltage (a large difference in the open-circuit voltage of identical strings or an open-circuit voltage very different to that expected may indicate a problem;  measurement of array/string short-circuit current  measurement of voltage drop across string fuses  verification of polarity of installed components;  Testi ng Example for testing checklist Commissioning  Commissioning will be the first time the complete system is switched on and able to feed electricity into the grid.  This process is normally covered in great detail by national codes and standards, with which any electrician undertaking PV system commissioning should be very familiar.  It is particularly important that the PV system disconnects and reconnects to the grid in accordance with local standards.  The following table outlines the necessary post- commissioning tests to ensure the system is functioning with the grid and operating as expected. Commissioning  The following table outlines the necessary post- commissioning tests to ensure the system is functioning with the grid and operating as expected.  System  documentation At the completion of the installation the owner should be supplied with a system manual that includes information on the system.  Local codes generally specify the documentation including that PV modules, inverters, array frames, should be provided, including: PV combiner boxes, string isolators, fuses or circuit breakers and the DC a AC main  List of equipment supplied disconnects/isolators. The system manual should include a full itemized list of all the components that have been installed  System  documentation At the completion of the installation the owner should be supplied with a system manual that includes information on the system.  Local codes generally specify the documentation that should be provided, including:  System diagrams A basic circuit diagram and a wiring diagram should be included in the manual. Architectural drawings or the site plan showing the major components are also useful.  System  documentation At the completion of the installation the owner should be supplied with a system manual that includes information on the system.  Local codes generally specify the documentation that should be provided, including:  System performance estimate: The manual should include the expected yield of the system as calculated by the designer It is also important to emphasize that this is purely an estimate and some variation from year to year is common.  System  documentation At the completion of the installation the owner should be supplied with a system manual that includes information on the system.  Local codes generally specify the documentation that should be provided, including:  Operating instructions for the system and its components The manual should include a brief overview of the system, the function of each of the main components and how the system operates. Any information important to that particular system should be included in the manual. It is important to explain to the owner that the system will deal with the  System  documentation At the completion of the installation the owner should be supplied with a system manual that includes information on the system.  Local codes generally specify the documentation that should be provided, including:  Monitoring of system A section of the manual should advise the system owner how to monitor the system to ensure that it is operating correctly. Many inverters have monitoring capabilities. If the inverter includes these features, instructions on how to use them should be provided. Questi ons