J. Schlabbach

Bio: J. Schlabbach is an academic researcher from Applied Science Private University. The author has contributed to research in topics: Fault (power engineering) & Turbine. The author has an hindex of 1, co-authored 1 publications receiving 33 citations.

Low voltage fault ride through criteria for grid connection of wind turbine generators

Abstract: This paper deals with the performance of grid-connected wind-turbine generators in case of system faults, i.e. short-circuits, the so-called low-voltage-fault-ride-through-conditions (LVFRT-conditions). Furthermore the requirements of frequency, voltage and reactive power control are explained. The conditions are defined in the grid-codes of the utilities even in Europe in a different way, leading to contra dictionary operating conditions in the interconnected UCTE-system. The increasing importance of electricity generation by wind turbines in the future requires similar and standardized operating criteria for all countries.

A review of grid code technical requirements for wind farms

Abstract: This paper provides an overview of grid code technical requirements regarding the connection of large wind farms to the electric power systems. The grid codes examined are generally compiled by transmission system operators (TSOs) of countries or regions with high wind penetration and therefore incorporate the accumulated experience after several years of system operation at significant wind penetration levels. The paper focuses on the most important technical requirements for wind farms, included in most grid codes, such as active and reactive power regulation, voltage and frequency operating limits and wind farm behaviour during grid disturbances. The paper also includes a review of modern wind turbine technologies, regarding their capability of satisfying the requirements set by the codes, demonstrating that recent developments in wind turbine technology provide wind farms with stability and regulation capabilities directly comparable to those of conventional generating plants.

Enhancing Low-Voltage Ride-Through Capability and Smoothing Output Power of DFIG With a Superconducting Fault-Current Limiter–Magnetic Energy Storage System

Abstract: Two major problems that are faced by doubly fed induction generators are: weak low-voltage ride-through capability and fluctuating output power. To solve these problems, a superconducting fault-current limiter-magnetic energy storage system is presented. The superconducting coil (SC) is utilized as the energy storage device for output power smoothing control during normal operation and as a fault-current limiting inductor to limit the surge current in the stator or rotor during the grid fault. The SC can also weaken the rotor back electromotive force voltage, and thus enhance the controllability of the rotor-side converter (RSC), which helps to protect both the RSC and the gearbox. Simulation results verify the efficacy of the proposed approaches.

Distributed Control of a Fault-Tolerant Modular Multilevel Inverter for Direct-Drive Wind Turbine Grid Interfacing

Abstract: Modular generator and converter topologies are being pursued for large offshore wind turbines to achieve fault tolerance and high reliability. A centralized controller presents a single critical point of failure which has prevented a truly modular and fault-tolerant system from being obtained. This study analyzes the inverter circuit control requirements during normal operation and grid fault ride-through and proposes a distributed controller design to allow inverter modules to operate independently of each other. All the modules independently estimate the grid voltage magnitude and position, and the modules are synchronized together over a controller area network (CAN) bus. The CAN bus is also used to interleave the pulsewidth modulation switching of the modules and synchronize the analog to digital converter (ADC) sampling. The controller structure and algorithms are tested by laboratory experiments with respect to normal operation, initial synchronization to the grid, module fault tolerance, and grid fault ride-through.

Low voltage ride through capability of a 5 kW grid-tied solar inverter

Abstract: Distributed power generation systems (DPGS) such as wind and solar become more and more widely spread. As a consequence grid operating companies demand system services. As part of the general fault ride through (FRT) requirements this paper deals with low voltage ride through (LVRT) capability of a three-phase-four-wire grid-tied solar inverter. The standard system will be described and necessary changes to the control such as positive (PS), negative (NS) and zero sequence (ZS) separation, a stable phase-locked-loop (PLL) as well as voltage support by means of reactive current as well as stress factors to the hardware will be identified.

Cooperative Control of SFCL and SMES for Enhancing Fault Ride Through Capability and Smoothing Power Fluctuation of DFIG Wind Farm

Abstract: This paper deals with a cooperative control of a resistive type superconducting fault current limiter (SFCL) and a superconducting magnetic energy storage (SMES) for enhancing fault ride through (FRT) capability and smoothing power fluctuation of the doubly fed induction generator (DFIG)-based wind farm. When the system faults occur, the SFCL is used to limit the fault current, alleviate the terminal voltage drop, and transient power fluctuation so that the DFIG can ride through the fault. Subsequently, the remaining power fluctuation is suppressed by the SMES. The resistive value of the SFCL as well as the superconducting coil inductance of the SMES are simultaneously optimized so that a sudden increase in the kinetic energy in the DFIG rotor during faults, an initial stored energy in the SMES coil, an energy loss of the SFCL, and an output power fluctuation of the DFIG are minimum. The superior control effect of the cooperative SFCL and SMES over the individual device is confirmed by simulation study.