The magnetic storm results in the transmission lines with geomagnetically induced current (GIC). And GIC happening in random has the frequency between 0.001 Hz~0.1 Hz, and continues from several minutes to several hou...
详细信息
The magnetic storm results in the transmission lines with geomagnetically induced current (GIC). And GIC happening in random has the frequency between 0.001 Hz~0.1 Hz, and continues from several minutes to several hours. Based on elaborating mechanism and characteristic of GIC in grids and the influence on China power grids, the article has conducted the research work of GIC monitoring technology, and has investigated the method of sampling data of GIC, the survey algorithm and the new monitoring device. The simulated test shows, the monitoring device can effectively measure GIC which is signal of quasi direct current and randomness, has advantages of having few data to be handled and needing little memory space, etc
This paper presents a new approach for environmental/economic transaction planning model of the electricity market. The environmental/economic transaction planning problem is formulated as a multi-objective optimal po...
详细信息
This paper presents a new approach for environmental/economic transaction planning model of the electricity market. The environmental/economic transaction planning problem is formulated as a multi-objective optimal power flow (MOPF) problem. A novel algorithm using multiobjective particle swarm optimization (MOPSO) and non-stationary multi-stage assignment penalty function is proposed to solve this problem. PSO is modified by using dynamic neighborhood strategy, new particle memory updating, and one-dimension optimization to deal with multiple objectives. Incorporating of non-stationary multistage assignment penalty function in solving OPF problem can improve the convergence. The proposed method is demonstrated on the IEEE 30-bus system. The results show that the proposed approach can efficiently gain multiple pareto optimal transaction planning that match with the sustainable development strategy
This paper presents a multi-agent and WAN based adaptive coordinated protection system (MAWBACPS). The system utilizes IP intranet to realize real-time wide area information exchange of a power system. Multi-agent sys...
详细信息
This paper presents a multi-agent and WAN based adaptive coordinated protection system (MAWBACPS). The system utilizes IP intranet to realize real-time wide area information exchange of a power system. Multi-agent system's several good qualities to solve distributing problems are used to realize the coordination of the operation settings of protective relays. A new idea of effortful adaptation for power system protection is proposed, and a new method to determine adaptive coordinated relay settings of lines are proposed in this paper. Moreover, the structure, communication mechanism and coordination control strategy of MAWBACPS, and relating agents' design are presented. Experiment results illustrate that MAWBACPS can realize the coordination of protections, enable the back-up relays to use their adaptive settings in most situations, and efficiently improve the security of power system
In this paper, a novel HVDC transmission system is presented which is with parallel large capacitor connected in the DC side of the rectifier (shorted form HVDC-C). The fundamental principle and technology characteris...
详细信息
In this paper, a novel HVDC transmission system is presented which is with parallel large capacitor connected in the DC side of the rectifier (shorted form HVDC-C). The fundamental principle and technology characteristics of HVDC-C are analyzed. The study shows that HVDC-C reduces the component of harmonic voltage and harmonic current both side in AC system and DC transmission line, makes control strategy more flexible and the filter structure more simple, etc. Furthermore, the control method, contrast to conventional HVDC and application foreground of HVDC-C is discussed briefly. The simulations based on PSCAD/EMTDC show that HVDC-C can operate steadily, has the capability to restore steadily when short circuit fault occurs, and is feasible technically and obvious in advantages
A new load detection method was presented based on its running status of power system. The loads are sorted according to their index of capacitive, inductive, and none-linear. The static character of each load was got...
详细信息
A new load detection method was presented based on its running status of power system. The loads are sorted according to their index of capacitive, inductive, and none-linear. The static character of each load was got according to the time-distribution. The concept of load detection is completed. The data-sample and wave recording equipment is designed and assembled based on the DSP for power loads status detecting. The superior software was designed for data management and analyzing. The recognizing status data was analyzed in both time-domain and frequency-domain; the identifying method for electric power loads status is deduced based on the correlation coefficient; the mathematical model for the status identifying is built; the trueness and validity of the methods is verified based on the testing and analyzing
A new method to eliminate periodical narrow frequency noises in partial discharge detection of electric power system apparatus, Fourier series method, is presented. It uses the difference not only on frequency domain ...
详细信息
A new method to eliminate periodical narrow frequency noises in partial discharge detection of electric power system apparatus, Fourier series method, is presented. It uses the difference not only on frequency domain but also mainly on time duration between signals and noises. The anti-interference effect of this method was analyzed by experiments data on field. Several factors that can make influence to the affect of this method, such as the error of frequencies of the noise, the data length by which the Fourier coefficients are calculated, the error of A/D conversion, were discussed respectively. It was found that this method can almost completely banish narrow frequency noises, at the same time can retain the amplitude and polarity of partial discharge pulses, even if the main frequency of the partial discharge pulses are close to that of narrow frequency noises. The affect of this method was also contrasted with normal method, such as digital filter, adaptive filter and wavelet. The result shown that this new method has obvious predominance at remaining the amplitude and polarity of pulse signals.
Restoration of a power system after a complete blackout is a very important issue to the safety of the power system. Reasonable black start schemes are necessary to restore the power system as soon as possible. Based ...
详细信息
Restoration of a power system after a complete blackout is a very important issue to the safety of the power system. Reasonable black start schemes are necessary to restore the power system as soon as possible. Based on data envelopment analysis, a new strategy for assessing black start schemes is proposed in this paper. Schemes' technical verification is taken into consideration in the process of the assessment. Whether a scheme is effective is defined by employing its input and output indexes' values entirely. The application to a practical power system verifies that the method could provide dispatchers more comprehensive and objective decision references
power quality becomes an emphasis of related researches. Based on the detailed study on QCC (quality control center) of the FRIENDS first advanced by Japanese scholars, the functions of QCC are expanded and its basic ...
详细信息
power quality becomes an emphasis of related researches. Based on the detailed study on QCC (quality control center) of the FRIENDS first advanced by Japanese scholars, the functions of QCC are expanded and its basic types and structures are defined. Meanwhile, by detailed study, this paper introduces the multiple adjusting functions of UPQC (unified power quality conditioner) which is the chief part of QCC and presents its typical topological circuit. Moreover, H infin control technology is used to realize the synthesis tracking compensation of voltage and current for UPQC. Finally its validity has been testified successfully
A new ultra high-speed protection scheme is proposed in this paper. Using wavelet transform with multiresolution analysis, the current signals is decomposed into a series of detailed wavelet components. The spectral e...
详细信息
ISBN:
(纸本)9810557027
A new ultra high-speed protection scheme is proposed in this paper. Using wavelet transform with multiresolution analysis, the current signals is decomposed into a series of detailed wavelet components. The spectral energies of the wavelet components are calculated and then employed to detect the faults. Characteristics of the proposed ultra high-speed protection algorithm are analyzed and results of simulation studies are given. The results show that the proposed algorithm is promising and easy to implement for computer relaying application
A new non-unit voltage protection algorithm for extra high voltage (EHV) transmission lines is presented in this paper. The singularity of fault transient voltage signals in one terminal is utilized to discriminate cl...
详细信息
ISBN:
(纸本)9810557027
A new non-unit voltage protection algorithm for extra high voltage (EHV) transmission lines is presented in this paper. The singularity of fault transient voltage signals in one terminal is utilized to discriminate clearly between internal and external faults. Lipschitz exponent (LE) is obtained from wavelet modulus maximum to detect singularity of signals. A typical 500 kV EHV transmission system has been simulated by ATP to evaluate the scheme. The simulation results show that this scheme is capable of providing correct responses under various system configurations and fault conditions
暂无评论