Component testing for photovoltaic power plants (PVPP)

In March 2024, the first test facility of its kind in the Czech Republic was accredited for the verification of inverter compliance in cooperation with the Mechanical Engineering Testing Institute and Brno University of Technology (VUT Brno). The methodology "Verification of PPDS Requirements - Inverters for Generation Modules" has been developed, which sets out a uniform method and test procedure for verifying the compliance of 1-f and 3-f inverters with the requirements of the Distribution System Operation Rules, Annex 4 (PPDS:P4).

The set of requirements for electricity generating plants is based on Commission Regulation (EU) 2016/631 (issued on 14 April 2016) laying down a network code for the requirements for the connection of generation modules (generating plants) to the electricity grid (RfG).

The national implementation (via PPDS:P4) brings together, complements and specifies, within the framework of localisation, the requirements for the characteristics and behaviour of generation plants and generation modules in the electricity system for their connection to the distribution system (DS) in the Czech Republic.

We offer measurements related to:

non-synchronous production modules of category A1 (power limit up to 11kW),
non-synchronous production modules of category A2 (power limit 100kW),
an extension to category B production modules is in preparation
and are relevant for components:
PV grid inverters,
hybrid inverters in production mode,
inverters for battery storage systems in production mode,
1-f, 2-f, or 3-f devices,
with low-voltage grid connection.

Requirements for technical documentation:

Installation manual
Technical specification (datasheet, device settings)

Overview of tests and related requirements:

Maximum active power delivery
Ability to operate within the normal operating frequency range
Permissible power reduction at decreasing frequency
Ability to operate within the normal operating voltage range
Inverter performance specification
Resistance to rapid changes in frequency
Short-term voltage drop bridging - LVRT
Short-term voltage surge bridging - OVRT
Active power recovery after a fault (A2 only)
Power response to over frequency - P(f)
Voltage-dependent control mode - Q(U)
Dynamic behaviour - Q(U)
Voltage dependent active power limitation - P(U)
Dynamic behaviour - P(U)
Automatic connection under normal operating conditions
Automatic connection after a fault
Logic interface for interrupting active power supply
Undervoltage protection
Overvoltage protection
Overvoltage protection - 10 minute mean value
Underfrequency protection
Over-frequency protection
Adjustability and security against unauthorized access to settings

Testing facility at VUT Brno (BRNO UNIVERSITY OF TECHNOLOGY) here.

Significant changes have occurred for the introduction of new small photovoltaic power plants (PVPP) into operation in the Czech Republic, allowing distributors to end the five-year transitional period of using affidavits before the next period of expected growth in new electricity production.

The issued Certificate of Compliance with the Requirements of the PPDS at SZÚ/VUT for the verified inverter is provided in the Czech Republic as part of the process of connecting the plant to individual distribution companies in the Czech Republic. Further testing/verification according to the PPDS by distribution companies in the Czech Republic is no longer carried out.