Title :
Implementation and test of on-line embedded grid impedance estimation for PV-inverters
Author :
Asiminoaei, Lucian ; Teodorescu, Remus ; Blaabjerg, Frede ; Borup, Uffe
Author_Institution :
Inst. of Energy Technol., Aalborg Univ., Denmark
Abstract :
New and stronger power quality requirements are issued due to the increase amount of photovoltaic (PV) installations. In this paper different methods are used for continuous grid monitoring. By injecting a noncharacteristic harmonic current and measuring the grid voltage response it is possible to evaluate the grid impedance directly by the PV-inverter, providing a fast and low cost implementation. This principle theoretically provides a correct result of the grid impedance but when using it into the context of PV integration, different implementation issues strongly affect the quality of the results. This paper presents a new impedance estimation method including typical implementation problems encountered and it also presents adopted solutions for on-line grid impedance measurement. Practical tests on an existing PV-inverter validate the chosen solutions.
Keywords :
electric impedance measurement; invertors; photovoltaic power systems; power supply quality; power system interconnection; power system measurement; voltage measurement; PV-inverters; grid voltage response; noncharacteristic harmonic current; online embedded grid impedance estimation; photovoltaic installations; power quality requirements; Costs; Current measurement; Discrete Fourier transforms; Impedance measurement; Inverters; Monitoring; Power generation; Power quality; Testing; Voltage measurement;
Conference_Titel :
Power Electronics Specialists Conference, 2004. PESC 04. 2004 IEEE 35th Annual
Print_ISBN :
0-7803-8399-0
DOI :
10.1109/PESC.2004.1355330