Islanding detection is a mandatory function for grid-connected converters. The popular slip mode frequency shift (SMS) and auto phase active islanding methods are investigated an improved (IM)-SMS strategy proposed in this study. In the method, additional introduced to help stimulating action of algorithm simplified as well. When utility grid disconnected, keeps converter output voltage deviating until protection relay triggered. working principle method guidance parameters selection...

A novel, fast unblocking scheme for distance protection to identify symmetrical faults occurring during power swings has been proposed in this paper. First of all, the change rate three-phase active and reactive being cosine function sine with respect phase difference between two systems demonstrated. In case, they cannot be lower than threshold 0.7 after are normalized. However, will level off 0 when a fault occurs swings. Thereafter, cross-blocking is conceived on basis analysis. By virtue...

Synchronized wide area communication has become a mature technology, which makes the real-time interaction between substations and protection control system possible. However, present to handle this data been recognized be deficient. This paper begins by reviewing development history of power protection, with special attention paid recent in field wide-area integrated protections, order look into future systems. Then concept is introduced, where it can shown that hierarchical provides for or...

To ensure the continuous operation of voltage source converter based multi-terminal HVDC system (VSC-MTDC), there has been much concern regarding how to isolate single-pole earth fault by means protective relaying. However, when boundary components are not on dc transmission lines, conventional main protections for systems perform less satisfactorily. solve this problem, a local measurement-based ultra-high-speed protection is proposed, in paper. The proposed method achieved cooperation...

Recently, various strategies for energy management have been proposed to improve efficiency in smart grids. One key aspect of this is the use microgrids. To effectively manage a residential microgrid, advanced computational tools are required maintain balance between supply and demand. The concept load disaggregation through non-intrusive monitoring (NILM) emerging as cost-effective solution optimize utilization these systems without need extensive sensor infrastructure. This paper presents...

Based on the improved optimization objective function of fault diagnosis, a genetic algorithm-Tabu search (GATS) method is introduced for purpose diagnosis power systems. The algorithm has good global ability, while Tabu local ability. Integrating advantages these two algorithms, new hybrid algorithm, called GATS, can be obtained. Using Shcaffer, GATS are proven in this paper. results case studies show that superior to conventional methods terms sensitivity original solution and dependency...

To solve the following problem: action speed of protection based on a phasor is restricted by length filtering algorithm time window and vulnerability to false data, new pilot principle for transmission lines waveform similarity proposed in this paper. By comparing discrete point sets current sampling values, similarity-based called Hausdorff distance distinguishes difference between both side currents protected line, realizing fast identification, removal fault. Based characteristics...

This paper presents a novel phase change material based thermal energy storage system (PCMTESS) that is suitable for smart building management, together with its corresponding thermal-electric combined two-stage dispatching strategy. Benefiting from the materials' characteristic of absorbing or releasing significant amount heat at constant temperature, this endowed high capacity and relatively stable state during charge/discharge process. To evaluate performance PCMTESS, which integrated as...

A new scheme based on an improved correlation algorithm to distinguish between inrush and internal fault in the transformer is proposed. In this scheme, current over one cycle of each phase reorganized as a measurand. Fault currents can be distinguished from if waveform coefficient first half-cycle latter-half-cycle above measurand threshold. Test results show that all types faults, even those accompanied by magnetizing inrush, correctly identified with proposed algorithm. Besides high...

The characteristic of the single-phase earth fault in Peterse coil grounded distribution network is discussed this paper. It disclosed that only derivative zero-sequence current faulty feeder changes with controllable inductance Petersen coil, while sound kept invariable. Therefore, a novel selection criterion proposed. A variety simulation tests carried out. exactness and sensitivity proposed scheme are verified by test results.

To deal with the maloperation of distance protection in case power swings, criterion “concentric circle” was widely used. This is implemented based on time difference that apparent impedance locus passes through boundaries these two circles. In many cases (e.g., a very fast swing), it will fail to block. Actually, regard different moving loci, staying within gap between circles and corresponding internal operating circle have an inherent relationship. this paper, aforementioned relationship...

A universal wavefront positioning correction method on traveling-wave-based fault-location algorithms is proposed. According to the location accuracy analysis for faults of which fault positions change successively, it noted that real distance generally cannot be divided exactly by corresponding an integer sampling interval. It will lead unavoidable truncated error when discrete points are applied. Furthermore, disclosed can limited within a single interval simple identification in event low...

The strategies of distribution network reconfiguration are applicable for minimizing power loss and saving electrical energy in the system. Network is usually represented by constant load demand so ignoring variability causes uncertainty misleading results minimization loss. This paper consists two parts: first, was accomplished using an optimization framework based on to find sets optimal switches. active taken as objective function while bus voltage, branch current system radiality were...

Based on the comprehensive analyses of existing current differential protection criterion, a new type adaptive restraint coefficient-based criterion is put forward in line with variety fault conditions. The coefficient this can be adaptively adjusted according to operation and conditions system. In case, guarantee stability during external faults. Taking into account increasing applications extremely high voltage or even ultra-high transmission systems, work performed paper provided better...