Large-scale wind power integration will inevitably affect the dispatch of conventional resources, which could result in transmission line overload. Thyristor-controlled series capacitors (TCSCs) can be therefore installed in the transmission lines to change their series impedance so as to increase the loadability of the power system and reduce transmission losses. To address the highly uncertain characteristic of wind power output, a stochastic optimisation-based optimal TCSC planning model is proposed here. This model minimises the expected value of power loss cost and the investment cost of TCSC considering the probability of different scenarios, which are developed by using the classical copula theory, where the temporal interdependence between wind and load is taken into account. Mathematically, this optimal TCSC placement problem is formulated as a two-stage non-linear programme. Then the linearisation methods are adopted to transform the model to a mix-integer linear programme. Comprehensive case studies are carried out on the modified IEEE 57-bus test system, which demonstrates the effectiveness and efficiency of the proposed model.