Liu A.-G.,Nanchang University |
Wan H.-L.,Nanchang University |
Chen A.-J.,Suizhou Power Supply Company
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2012
Voltage stability is called load stability. In order to research the effect of load characteristics on voltage stability, accordingly, online voltage stability of a type of load model is researched. This paper puts forward a local equivalent method which is based on time section. For a researched node, the power grid is equivalent to a two-node system which is composed of a load and a power generation, and the local equivalent model parameters are worked out by using PMU measured voltage and current phasor. Taking static ZIP model as load model, voltage stability index expression is derived, which will be better to evaluate static voltage stability of system. The test about standard system shows that index has better linearity and higher precision by this method.
Feng B.,Suizhou Power Supply Company |
Xiao D.,Suizhou Power Supply Company |
Li Y.,Suizhou Power Supply Company |
Chen A.,Suizhou Power Supply Company |
Liu J.,Suizhou Power Supply Company
Gaoya Dianqi/High Voltage Apparatus | Year: 2015
Aiming at the limitation of the existing detection method of partial discharge(PD)in switchgear, a composite PD detection method is presented by combining transient earth voltage and ultrasonic method. The PD in a switchgear is detected with the present method in different artificially simulated humidity conditions, the PD detection results are analyzed, and the insulation of the switchgear is evaluated. Suggestions, such as setting infrared heater, adopting hydrophobic material for the insulation panel, are offered to improve the insulation condition of a switchgear. ©, 2015, Xi'an High Voltage Apparatus Research Institute. All right reserved.