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...

With the gradual replacement of synchronous generators by renewable energy sources, power imbalance in system is exacerbated fluctuations output. Simultaneously, traditional frequency regulation resources will become insufficient with reduction online capacity thermal units. These trends both lead to a decrease performance regulation. The planning generation, particularly resources, significantly influence future quality frequency. This paper proposes frequency-constrained generation method...

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...

This paper presents a measurement-based solution for low frequency oscillation (LFO) analysis in both real time monitoring and off-line case study. An online LFO property discrimination method is developed first, which alternately uses empirical mode decomposition (EMD)/Hilbert transform (HT) square calculation to process the measurement data. The magnifies variation trend of oscillating variables accurately discriminate oscillation. Subsequently, an source locating forced (FO) strongly...

Emergency islanding control is the last line of defense to avoid power system collapse, and it plays an important role in prevention large scale blackout. This paper carries out study slow coherency based adaptive controlled aiming design scheme applicable AC/DC interconnected systems. Firstly, a method proposed on mode information form complex number, which can deal with load buses. Then, several criteria are introduced determine whether hybrid grid suitable be split. Finally, used...

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,...

The integration of high shares variable renewable energy (VRE) makes the system's uncertainty increase sharply. It is technically and economically unsustainable to adopt traditional system reserve methods cope with uncertainties. Fully exploiting various flexible resources adapt VRE an important issue in operational planning future power systems. This paper considers demand response establish flexibility adequacy assessment indicators on supply side load side. Secondly, order reflect...

Under the background of "carbon neutralization, carbon peak", power generation enterprises vigorously develop clean energy, and some UHVDC supporting thermal units are replaced by new energy units. Considering that all plants under construction put into operation, subsequent can not be operation as planned, combined with current limited factors capacity, this paper proposes a scheme from two aspects controlling transient overvoltage level ensuring collection DC power, so to improve...

The integration of high-penetration renewable energy resources into the power system has posed increasing challenges to operators if strict constraints solar and wind curtailments are taken consideration. storage could provide ancillary service as it temporarily stores deal with variation generation, thus promoting consumption energy. Its effect on accommodation is well worth being evaluated so that suitable types sizes can be chosen minimize investment equipment. Moreover, other factors...

After the North China grid and Central get into connection with UHVAC demonstration, a new phenomenon is discovered according to some simulations.That is, faults at remote end of UHV interconnected will result in significant power fluctuation voltage drop on transmission line even system splitting.But near only have marginal effects.Further, simulation results also indicate that short-circuit current buses larger than far away from line.This divergent traditional view.In this paper, detail...

In the paper, a matter-element model and correlation functions of running state is established based on fuzzy decision making by high voltage circuit breaker operating evaluation index its diversity ambiguity. Based theory, which can run judge's classic domain, node to be evaluated established, use set calculation extension parameters status between levels, from size associated with degree qualitative quantitative qualitatively quantitatively, it finally verified examples usefulness this...

To solve the problem of variancy wind power when farm connect with grid, a predicting model based on double ANNs is proposed in paper. Wind velocity and direction are key predicting, other circumstance conditions such as temperature, humidity, atmospheric pressure, also great influence it. The observed values these five can be treated nonlinear time series analyzed by model. consists artificial neural networks. first consisted networks which used to prediction series, second employed use...

Based on environment economics analysis, the methodology of optimal capacity allocation pumped hydro storage plant(PHSP) for peak load regulation in power system with wind integration considering benefit contribution degree(EBCD) is proposed. The indices named degree and economic degree(ECBCD) are presented, which evaluate improvement green by PHSP separately. EBCD, ECBCD well-being requirement model, a model optimizing established, takes into account both EBCD PHSP. case studies were...

The UHVDC plays an important role to transmit renewable energy from the western base eastern load center in China. However, sending-end grids of UHVDCs are usually not strong enough and difficult ride through power flow transfer after DC failures, which significantly restrains capability efficiency UHVDCs. In conventional planning design, it is evaluate strength topology different schemes figure out preferable scheme. This paper proposes a grid vulnerability index based on entropy theory....