The Z100 PV Analyzer is a portable and battery powered instrument used to detect and locate faults in strings of series connected photovoltaic modules.

 

Instrument information

All Z100 analysis algorithms, assumes that the instrument is connected to a series string of solar PV modules. Correct fault position estimation can hence not be guaranteed, if the Z100 is connected to parallel coupled solar PV module strings.

Specifically, the instrument has the following features and measurement applications:

 

  • Measure position of a single ground fault in a PV string
  • Measure position of a single disconnect in PV strings
  • PV string impedance curves (health and degradation check)
  • PV string series resistance RS
  • PV string string open circuit voltage VOC
  • PV system isolation resistance RISO
  • PV module voltage
  • PV module bypass diode check
  • PV module shunting resistance (module/cell degradation)
  • Integrated timer for periodic faults
  • Tone generator and tone tracer pickup
  • Build in PDF report generator

 

Instrument introduction and WiFi operation

The instrument is connected to the string terminals e.g. at the string inverter or combiner box and also to the ground reference for the PV installation.
Once connected and activated, it will perform impedance spectroscopy between any two of the three connected terminals, as well as measure the terminal voltages and currents flowing under various DC loads introduced by the instrument. By combining the results from these various measurements using the on-board computer, critical faults in the system can be defined and positioned.

Requirements for controller devices

The controller device may be a smartphone, a tablet computer or a PC / MAC. It is left to the user to choose his preferred device. In some situations a smartphone may be sufficient, and in other cases when evaluating data, a device with a larger screen may be preferred.

 

Recommended internet browsers for controller devices

The Z100 PV Analyzer has been optimized for use with the following internet browsers. Google Chrome browser

Apple Safari browser

Firefox browser

Please note that using other browsers, such as e.g. Microsoft Internet explorer, is not recommended and full functionality can not be guaranteed in such cases.

Applications and measurements

 

Some rudimentary control and assessment of the light reaching the string and individual PV modules is necessary. I.e. in order to accurately detect and localize ground faults, and disconnects in cables and connectors, all the modules in the string under test need to be illuminated by at least 100 W/m2.
The most accurate results are obtained when the irradiation level is steady throughout your measurement. This is also the case if you want to estimate the overall string series resistance RS. When checking the health state of module bypass diodes it is also necessary with ambient sunlight intensity at each module of at least 100 W/m2. Please note that testing the health state of the diodes in a specific PV module in the string, requires blocking the sunlight from reaching that module. If RS of the string or a subset of the string down to individual cells or modules needs to be measured the sunlight needs again to be blocked from reaching the PV cells or modules being tested, however this can be achieved by measuring at nighttime (I.e. RS of the entire string).

WiFi setup and Z100 WiFi basics

Step 1

You will communicate with the Z100 through a browser window at all times. After turning on the instrument, the internal computer will set up a WiFi hot spot (local wireless network) that can be connected with other WiFi devices, so make sure that WiFi on your preferred smart device (smartphone, tablet or laptop) is enabled.

Step 2

The name of the hot spot access point will be in the form: ”Z100-xxxx-xxxx”, where x represents unique numbers for every Z200 hot spot. Once you have found the hot spot simply connect using the password: Xoplag10.

Step 3

Open your internet browser (e.g. google Chrome) and type: ”z100/” in the URL bar. If you are already connected to the internet by other means, you have to type ”192.168.4.1” instead, as this signifies to your device not to look up the Z100 through a DNS server, but only find it within the local WiFi network itself.

Step 4

When using a new browser to access the Z100 for the first time, it might be necessary to enable PopUps for the Z100 homepage, in order to allow it to store PDF reports from your subsequent measurements. This is e.g. done within Chrome by clicking on the ”No PopUp” icon, that appears to the right of the URL-address bar AFTER creating the first PDF report (It is only needed the first time you generate a report).

Step 5

Optional: With Chrome it is possible to make a shortcut to the Z100 homepage, so you can open up directly to the Z200 with an icon of its own. Go to the Z100 homepage, and open the menu to the right of the URL address bar and tap on ”Add to home Screen”.