Inverse star-mesh transformation and network-element-value observability

The linear transistor resistor network fault diagnosis problem is considered. The difference between the analog fault diagnosis problem and the network element value observability problem is made clear. It is shown that the network element values are observable if all network element values are determined uniquely by the measured data with the accessible nodes and by the network topology. After discussing the two terminal resistor network, the authors consider some sufficient conditions for the transistor network to be observable. A method for calculating the element value for a multi-star inaccessible network is proposed. The method presented is fundamentally derived from the special property of submatrices of the indefinite admittance matrix for the network