This paper studies the fault current frequency spectrum characteristics of single phase ground fault in ungrounded distribution networks, and the fault location method based on it. Firstly, it analyzes the production ...
详细信息
This paper studies the fault current frequency spectrum characteristics of single phase ground fault in ungrounded distribution networks, and the fault location method based on it. Firstly, it analyzes the production mechanism of 2 nd major frequency component, and the relationship between the 2 nd major frequency component and series resonance frequency of the faulted line. Secondly, from the perspectives of lumped-parameter circuit, the relationship between 2 nd major frequency component and fault location is deduced. simulation cases are used to confirm the relationship. Last, the impact of load and initial fault phase angle on the 2 nd major frequency component are researched. simulation research proves the feasibility of the fault detection and location method based on frequency domain characteristics.
Multi-bay information sharing has very important significances for the the enhancing of the relay characteristics and improving of the systemcontrol methods. With the summary of distribution substation busbar protect...
详细信息
According to the demand of 126kV intelligent switch with intelligent operative box, an intelligent terminal device by using cooperation control of embedded CPU (STM32F103ZET6 ARM) and Field Programmable Gates (Cyclone...
详细信息
The stability and reliability of the intelligent terminal's receiving information affects its control of intelligent switch in operation directly. To achieve reliable intelligent communications terminals, with tec...
详细信息
A fast DC-link voltage controller is desirable to reduce the DC-link capacitor for PV inverters. This paper proposes a method for single-phase grid-connected PV inverters to remove the ripple component from the DC-lin...
详细信息
ISBN:
(纸本)9781457705427;9781457705410
A fast DC-link voltage controller is desirable to reduce the DC-link capacitor for PV inverters. This paper proposes a method for single-phase grid-connected PV inverters to remove the ripple component from the DC-link voltage signal and a scheme to regulate the DC-link voltage based on energy-balance analysis. The proposed scheme provides excellent dynamic performance as well as a function to prevent DC-link overvoltage by limiting the input power, which is verified by both simulation and experiments.
The development of digital substation provides new opportunity for integrated protection. However, the realization of integrated protection is constrained by serial communication between process level and bay level. B...
详细信息
The transient pressure process, which determined the gas blasting in the interrupter of SF6 circuit breaker, have attracted the attention of designer and developer for long time. In this investigation, a onload SF6 in...
详细信息
ISBN:
(纸本)9781457712739
The transient pressure process, which determined the gas blasting in the interrupter of SF6 circuit breaker, have attracted the attention of designer and developer for long time. In this investigation, a onload SF6 interrupter pressure measurement method was established with piezoresistive pressure transducer and insulating-tube. The pressures in the puffer cylinder, at the upstream, throat and downstream of nozzle have been measured. The difference of gas blowing characteristics between N2 and SF6 has been pointed out. The insulating-tube can effectively protect the pressure transducer from the high voltage and high temperature during on-load interrupting. It was found that the arc process can cause high frequency oscillations to superimpose upon the pressure waveforms during on-load interrupting.
Lightning is a major cause of power interruptions in power transmission *** the Leader Progression Model is an advanced method to evaluate the shielding failure probability of transmission *** the surface electric fie...
详细信息
Lightning is a major cause of power interruptions in power transmission *** the Leader Progression Model is an advanced method to evaluate the shielding failure probability of transmission *** the surface electric field on phase conductors and ground wires precisely is important, because the surface electric field has great effect on the upward leader *** this paper, the influence of lightning current and some other factors on surface electric field were analyzed.
The interaction of nanoseconds, microseconds, milliseconds electromagnetic transients due to AC-DC system operation and fault, the DC converter valve movement, the load generated by changes in the interaction of AC-DC...
详细信息
The interaction of nanoseconds, microseconds, milliseconds electromagnetic transients due to AC-DC system operation and fault, the DC converter valve movement, the load generated by changes in the interaction of AC-DC interconnected system electromagnetic transient, can pose a hazard on AC and DC powersystems, in particular, lead to the commutation of DC system failures and artesian such serious incidents. Combining theoretical analysis with test, we can establish the analysis method of electromagnetic transient of the full-wave process of the UHV system based on AC-DC interconnected system, controlsystems, and underground grounding system, and focus on the equivalence circuit of AC side network with the Ward method of equivalency under many operation modes and steady-state debugging for the analysis of AC-DC interconnected system, so as to lay the foundation for the interaction of electromagnetic transient.
The implementation of non-communication protection of double circuit line systems based on two independent relays has disadvantages like information shareless,complex connection and lack of economic. This paper resear...
详细信息
The implementation of non-communication protection of double circuit line systems based on two independent relays has disadvantages like information shareless,complex connection and lack of economic. This paper researched the implementation of non-communication protection of double circuit line systems based on one relay - the integrated protection platform. Hardware structure of the integrated protection platform is described, and software flow of non-communication protection of double circuit line systems which implemented on the integrated protection platform is also described. Large number of RTDS experiments proved that, according to various asymmetrical fault and symmetrical fault, this protection scheme has reliable and sensitive action performance. It is proved that the implement non-communication protection of double circuit line systems based on the intergrated protection platform is feasible.
暂无评论