Subsynchronous Control Interaction Research Articles

Study of Sub-Synchronous Control Interaction (SSCI) Based on the Test Signal Method

Large-scale wind turbine generators with power electronic converters that operate near series compensated transmission lines are susceptible to un-damped sub-synchronous oscillations. This sub-synchronous oscillation is called Sub-synchronous Control Interaction (SSCI). Based on PSCAD / EMTDC simulation platform the establishment of Double Fed Induction Generator (DFIG) equivalent inverter controlled sources and network model, and verify the correctness of the equivalent model. Analysis the impact of series compensation and rotor-side converter PI parameters characteristic of the SSCI based on test signal method and time-domain simulation method. The results show that increasing the degree of series compensation , inner gain constant increases and inner integral time decreases will help increase SSCI, outer ring of PI parameters has little effect on the SSCI .

Study on Sub-Synchronous Control Interaction (SSCI) of Wind-Power Generator

Large-scale wind turbine generators with power electronic converters that operate near series compensated transmission lines are susceptible to un-damped sub-synchronous oscillations. This sub-synchronous oscillation is called Sub-synchronous Control Interaction (SSCI). With the rapid development of wind power technology, SSCI emerges as a new sub-synchronous oscillation phenomenon. The first SSCI event occurred for a wind farm in America in2009, which resulted in damage to the wind turbines. The origin of SSCI is presented and its characteristics of different types of wind turbines are summarized. Then the research prospect on this field is explored.

A study of recent changes in Southwest Power Pool and Electric Reliability Council of Texas and its impact on the U.S. wind industry

Abstract Due to the increased penetration of renewable energy resources, there has been a lot of activity in the regional transmission organizations such as development of new standards, protocol revisions, new study requirements, changes to modeling procedures etc., in the last five years with a special focus given to wind energy. The key objective of this paper is to identify the impacts and the immediate technological and market related improvements required by the wind industry as a result of such changes in Southwest Power Pool (SPP) and the Electric Reliability Council of Texas (ERCOT). The paper documents the most important activities by following the higher‐priority committees, work groups and task forces in both companies along with some of the special projects or initiatives such as sub-synchronous control interaction study, primary frequency response, hub concept and other modeling improvements related to wind energy. The paper provides an analysis of the impact of each change resulting in technology upgrades to wind turbines, modeling improvements by turbine manufacturers and policy/market changes affecting wind farm developers. Finally the paper provides recommendations regarding the requirements and capabilities which the future wind farms and wind turbines need to possess.

Subsynchronous Interaction and its Mitigation in DFIG-Based Wind Farm and Turbine-Generator Bundled Systems

This paper investigates the subsynchronous interactions (SSI) in DFIG-based wind farm and turbine-generator (T-G) bundled system which is integrated through series compensated transmission line, the results reveal that the integration of DFIG-based wind farm could improve the subsynchronous resonance (SSR) damping of the nearby turbine-generators. Then supplemental controls of DFIG-based wind farm are used to mitigate subsynchronous control interaction (SSCI) of the DFIG and multi-mode SSR of the nearby turbine-generators. The supplemental controls are added to the reactive power control loop of GSC (grid side converter) for DFIG. Given that no additional device is needed, this supplemental control could be the most promising measure for SSR and SSCI mitigating.

General Methodology for Analysis of Sub-Synchronous Interaction in Wind Power Plants

This paper presents a general methodology for analysis of sub-synchronous interaction in wind power plants. These include appropriate frequency scanning method for the assessment of the sub-synchronous control interaction, and calculation of the electrical damping provided by the wind turbine generator for investigation of the sub-synchronous torsional interaction. A general formulation of both methods applicable to any given wind turbine and network is presented. A dynamic frequency scanning method for the turbine side is developed which takes account of the turbine nonlinearities and its active behavior. Various aspects that need to be considered when injecting a voltage or current signal into the system for dynamic frequency scanning are discussed in detail. The veracity of these methods is confirmed against electromagnetic transient analyses. The application of these tools and techniques is demonstrated on a practical power system comprising type 3 wind turbines and series compensated lines.

Reactance Scan Crossover-Based Approach for Investigating SSCI Concerns for DFIG-Based Wind Turbines

This paper presents a reactance crossover-based technique to investigate subsynchronous control interaction (SSCI) concerns associated with doubly fed induction generator-based wind generation resources. A theoretical discussion serving as the mathematical premise for the proposed approach is presented. The driving point reactance, as seen from the WGR, across the subsynchronous frequency range is determined using four different approaches. Specifically, two of the four methods (Methods 3 and 4) are unique in terms of the approach utilized for performing frequency scans. System-side frequency scans are augmented with turbine-side frequency scans. A dynamic frequency-scanning method for the turbine side is developed which takes the turbine nonlinearities and its active behavior into account. The presence of crossover points in the reactance scans, as obtained from four approaches, in conjunction with the turbine-side frequency scans is utilized to draw conclusions on potential SSCI concerns. A portion of the Electric Reliability Council of Texas grid model has been utilized for the case study. The observations/inferences drawn via the reactance scans are corroborated via electromagnetic transients simulations.