The method uses the average and root mean square of the VSC converter current to estimate the conversion losses in the converters (conduction and switching losses). The remaining power losses (DC cable transmission losses due to I2R, the losses in the coupling transformer, and AC harmonic filter losses) are evaluated using conventional well-known methods. In this proposed implementation based on a small-signal stability, voltage stability, and interaction phenomena of power systems with both line-commutated-converter HVDC (LCC-HVDC) and voltage-source-converter HVDC(VSC-HVDC) are addressed using the proposed implementation. In this implementation, the entire power system is modeled as a multivariable feedback control system (FCS) which consists of three interconnected blocks. The contents as well as the inputs and outputs of the blocks are selected such that the conventional analysis tools for power system stability are applicable, both in the time and frequency domains. In the FCS model, the relationships between different instabilities are clear, and participant agents of each instability can be determined. This proposed work is implemented in Matlab simulink environment.