Method For Operating An Electrical Apparatus

摘要

A method and device for operating a fluid-insulated electrical apparatus. The insulation fluid of the electrical apparatus includes at least two components. The method includes the step of determining a physical state of the insulation fluid by measuring at least three measurement variables with sensors. The method further includes the step of deriving trend variables indicative of changes over time for the measurement variables and/or for characterizing variables. These characterizing variables are derived from the measurement variables by using a relating equation, such as an equation of state, and are also indicative of the physical state of the insulation fluid. By testing for specific patterns of the trend variables, an operating state of the electrical apparatus is determined. The possible operating states correspond to specific and distinguishable non-fault and fault scenarios for the electrical apparatus. Thus, operating states can be distinguished and trouble-shooting in case of a failure is simplified.

主权项

1. A method for operating a fluid-insulated electrical apparatus, in particular gas-insulated medium or high voltage switchgear, wherein an insulation fluid of the electrical apparatus comprises at least a first component and a second component, the method comprising the method elements of:
determining a physical state of the insulation fluid by measuring at least three measurement variables by means of at least one sensor, wherein the measurement variables, indicative of the physical state of the insulation fluid and wherein the measurement variables are selected such that at least two characterizing variables indicative of partial pressures (pA, pB) or concentrations (cA, cB) of the first component and the second component of the insulation fluid can be determined using the measurement variables, wherein the method comprises a further method element of: deriving at least one trend variable for at least one of the measurement variables, wherein the at least one trend variable is indicative of a change over time of the at least one measurement variable; and/or a further method element of: deriving from at least one of the measurement variables at least one of the characterizing variables, wherein the at least one of the characterizing variables is indicative of the physical state of the insulation fluid, and deriving at least one trend variable for the at least one of the characterizing variables, wherein the trend variable is indicative of a change over time of the at least one of the characterizing variables; wherein at least two trend variables are derived for the at least two characterizing variables indicative of the partial pressures (pA, pB) or concentrations (cA, cB) of the first and second components of the insulation fluid, and wherein the at least two characterizing variables are selected from the group consisting of: a function f1(pA), a function f2(pA/T), a function f3(pB), a function f4(pB/T), a function f5(pA, pB), a function f6(pA, pB, T), a function f7(pA/pB), a function f8(cA), a function f9(cB), a function f10(cA, cB), and a function f11(cA/cB), with pA and pB being the partial pressures of the first and second components of the insulation fluid, with cA and cB being the concentrations of the first and second components of the insulation fluid, and with T being a temperature T of the insulation fluid; wherein further the method comprises a method element of:
determining, using the at least one trend variable for the at least one of the characterizing variables, an operating state of the electrical apparatus out of a group of at least two possible operating states.