Design Of Primary Equipments On-line Monitoring System In Smart Substation

The on-line monitoring system of primary equipment of Smart substation is a real-time monitoring system for high-voltage equipments’ running status. In morden society, electricity has become an important energy use in the production of life, power equipment, which is running for long time, prone to a series of problem such as equipment aging, fault and insulation but their fault symptom is not obvious, maintenance difficulties and maintenance cycle is long. So monitoring the high-voltage equipment and timely reflect the working condition of equipment, insulation problem, then replace the equipment before they get serious problems. This system can prevent blackouts accidents and improve power system stability. In this paper, the monitoring is mainly for high-voltage equipments such as gas insulated switchgear、high-voltage circuit breaker、electrical transformer and arrester for on-line monitoring. The paper completed the following work:1. Introduced current situation and development trend of on-line monitoring technique, constructed the monitoring system of primary equipment of smart substation. Compared the advantages of each monitoring method of the high-voltage equipments and established the related monitoring subsystems. The performance of partial discharge signal in GIS propagation characteristics and UHF high frequency antenna are analyzed in detail, according to the signal characteristics, design a frequency reduction circuit and the sampling method.2. The principle of each equipment was analyzed. Design circuits for signal processing, according to different equipments selected different monitoring signal、data-collection equipment and shielding means. Selected Sym5 wavelet of Sym wavelet series and the "heursure" of threshold selection for the five layer wavelet decomposition, and the de-noising effect is analyzed by simulation signals.3. Used micro chip and Ethernet controller as the intelligent processing unit, design the hardware of interface function and connection method. Analyzed the Standard of IEC61850 and design a protocol for substations’ communication which conformed to the standard. Design the communication frame’s format for SV-sampling communication、GOOSE communication and the way protocol worked.4.Applied double peak of spectral lines algorithm to the monitoring system of dielectricloss、harmonic current and breaking current. The algorithm can improve the signals’ accuracy in frequency, amplitude, phase for each harmonic. 5. Designed the program of communication protocol’s system, equipment-monitoring system, fault-diagnosis system, based on software platform of Lab VIEW. The state of the equipment and the diagnosis result can be display in the monitoring interface timely.To saving and loading failure data, this system has also developed a database.