Modeling of the Hydro-Quebec-New England HVDC system and digital controls with EMTP

The commissioning of the Quebec-New England multiterminal DC transmission system underscores the increasing need to develop numerical models for simulation purposes. The modern microprocessor-based HVDC (high-voltage direct-current) converter controls used in this scheme make the modeling a real challenge since the Electromagnetic Transient Program (EMTP), usually employed for simulation purposes, and Transient Analysis of Control Systems (TACS) were designed to simulate analog, not digital controls. Details on the modeling of digital controls with a modified EMTP version are given. Some comparisons with HVDC (high-voltage direct current) simulator results which show good agreement between the two power system analysis tools are presented. A case that is validated with field test results is also included