Photovoltaic Module Evaluation System

PID creates an output drop in PV modules
Automatically measures leak current resulting from PID in high temperature and humidity environments

Potential Induced Degradation (PID), which occurs in solar power systems, is a degradation phenomenon caused by a leak current due to a large potential difference occurring in the PV module frame and module circuit. PID is believed to be one factor for lowering the output of solar power systems, and it is said that humidity promotes this phenomenon.

ESPEC’s PID Evaluation System measures the leak current by applying high-voltage current in a high temperature and humidity environment with high accuracy and excellent reproducibility so as to accurately evaluate this PID phenomenon. This system is essential in evaluating PV module degradation.

Photo: Inside

Figure: Flow of leak current due to PID (between frame and cell)

Features
  • Temperature and humidity chamber and voltage application insulation resistance measurement system
    This system comprises a temperature and humidity chamber for testing safety and easy setting of the PV module and a high-voltage application insulation resistance measurement system for measuring the leak current between the frame and cell and for controlling the entire system.
    You can choose the temperature and humidity chamber according to the module size.
  • Measure Leakage current of 10 PV modules at the same time
    Apply a voltage up to ±1.5 kV to each of 10 PV modules (max. size: 1,800 × 1,500 × 50 mm), and measure and record the leak current. It comes with a temperature and humidity chamber (inside chamber) and a rack that uses a resin insulation material and can be installed in an electrically insulated condition.
  • Independently grounded to prevent high-voltage electrostatic charge
    The plate on the inside of the door of the temperature and humidity chamber, the interior, and the electrical components on the transformer secondary side are each wired to the grounding terminal to prevent electrical shock accidents.
  • Various safety specifications to support high-voltage tests
    The door has a locking mechanism to prevent accidental opening during high-voltage tests, and an interlock forcibly stops high-voltage application when the door is open.
Functions
  • Fault determination function
    A leak current value is set in advance to determine a fault, and when that value is exceeded, high-voltage application to the PV module is stopped.
  • High-speed leak detection function
    Leak currents are detected with a measurement speed of 20 msec.
    Sudden fluctuations in leak current are also detected.
  • Slow voltage application control function
    To control the PV module load at high-voltage increases, the voltage is gradually increased, thereby decreasing the load.
Specifications (example)

Temperature and humidity chamber

FMS-4050
Temperature and humidity control range ±1.5°C / ±5%rh
Temperature and humidity distribution -40°C to +100°C / 40% to 95%rh
Inside dimensions W1200 × H1650 × D2000mm
Outside dimensions W1720 × H2370 × D3300mm

* We can provide a temperature and humidity chamber to suit your needs depending on the number of modules and their size.

Measurement system part

AMIK-2000
Application voltage range ±10V to ±1500V
(Polarity can be changed using the relay box part)
Leak current measurement range ±0.1pA to ±1mA
(The display is the absolute value display of the positive polarity)
High-speed leak detection function Range  ±4μA to 100μA
Detection speed  Approx. 20 msec
Number of channels 20ch
Outside dimensions W530 × H1750 × D1040mm
(Excluding relay box part)