Power-system sub-synchronous oscillation (SSO) caused by direct-driven permanent magnetic synchronous generator-based wind farms has attracted significant attention from researchers. An equivalent model (EM) is typically used to describe the farm dynamics; however, very few works investigated suitability of EMs for SSO-based research studies. In this paper, a method evaluating applicability phenomena that takes into account wind-power (WP) randomness proposed. First, EM parameter calculation...

Recently, explanations of the sub-synchronous oscillation (SSO) caused by wind farms based on direct-driven generators (DDWGs) have been published in literatures, which controller parameters DDWGs and system equivalent play an important role. However, more than one set can cause weakly damped modes. The most vulnerable highly possible scenario is still unknown. To find scenarios that potential risks, this paper proposes a small disturbance model with connected to grid using state-space...

In recent years, sub-synchronous oscillation accidents caused by wind power integration have received extensive attention.The recorded constant-amplitude waveforms can be induced either linear or nonlinear mechanisms.Hence, the behavior needs to distinguished prior choosing analysis method.Since 1960s, higher-order statistics (HOS) theory has become a powerful tool for detection of (DNB) in production quality control wherein it mainly been applied mechanical condition monitoring and fault...

Recently, several literatures reported that sub-synchronous oscillation (SSO) events occurred in wind farms based on direct-driven generators (DDWGs). This paper focuses whether a farm consists of only DDWGs would bring an SSO. First, small-signal model the DDWG-based is proposed. Eigen-analysis indicates there are natural modes with frequency; however, their damping ratios significantly large under specific control parameters. Further, relationships between and number grid-connected DDWGs,...

Abstract The sub-synchronous oscillation (SSO) which occurred in direct-driven wind generators (DDWG) based farms became a research hotspot. SSO excited the shaft torsional vibration of thermal and caused trip failures, leading to economic losses stabilization problems. However, existing phasor-based source locating methods cannot be applied since power system quasi-steady-state assumption was not satisfied scenarios. Thus, novel method for sources urgently required. To fill this gap, paper...

The quality of distribution network equipment is the basis construction intrinsically safe system, and sample inspection delivered an important means control equipment. Centering on problem that transformer capacity hard to be inspected accurately at present, this paper proposes a new method for based big data. This accumulates large number test data nearly one thousand transformers from work, analyzes volume, weight, DC resistance, no-load loss, load loss short-circuit impedance in...

In this paper, we investigate the continuous time partial primal-dual gradient dynamics (P-PDGD) for solving convex optimization problems with form $ \min\limits_{x\in X,y\in\Omega}\ f({x})+h(y),\ \textit{s.t.}\ A{x}+By=C $, where f({x}) is strongly and smooth, but h(y) non-smooth. Affine equality set constraints are included. We prove exponential stability of P-PDGD, bounds on decaying rates provided. Moreover, it also shown that can be regulated by setting stepsize.

The oscillation phenomena associated with the control of voltage source converters (VSCs) are widely concerning, and locating these oscillations is crucial to suppressing them; therefore, this paper presents a scheme, based on energy structure nonlinearity detection. On one hand, structure, which conforms principle energy-based method dissipativity theory, constructed describe transient flow for VSCs, basis, defined characteristic quantity implemented narrow scope location; other according...

The incremental negative damping characteristics of pulsed loads have adverse effects on the stable operation independent power systems. diesel generator set is most important source in system. It necessary to conduct analysis and enhance system by increasing energy dissipation generator. Based Hamilton realization, this paper analyzes internal structure fifth order model an with a load. A method reduce term proposed improve robustness This verifies based PSCAD/EMTDC simulation. provides...

The leakage inductance of the transformer usually has bad effects on circuit performance, especially in power converters. often causes voltage spikes switches. In order to get smaller for high frequency transformer, method minimum inductor based segmentation interleaving coefficient is proposed this paper. Interleaving segmented winding adopted optimize design transformer. How arrange windings make minimize been proved with mathematical calculation condition 3 layers each winding. addition,...

In recent years, the sub-synchronous oscillation (SSO) accidents caused by wind power have received extensive attention. A method is needed to distinguish if nonlinear behavior exists in recorded equal-amplitude accident waveforms, so that different methods can be adopted analyze mechanism of oscillation. The theory higher-order statistics (HOS) has become a powerful tool for detection (DNB) production quality control since 1960s. However, HOS analysis been applied mechanical condition...

In recent years, the sub-synchronous oscillation (SSO) accidents of power system caused by wind have received extensive attention. This paper focuses on self-sustained problem control limit grid-following direct-driven permanent magnet synchronous generator (PMSG) farms. When one PMSG in a multi-machine oscillates, whether removal other PMSGs can affect its conditions is studied. this paper, tripping scene farm with transformed into influence equivalent parameter change two-machine coupling...