An approach to partition power system simulations formulated in mesh currents as variables is presented. Time-domain simulations of large-scale power systems are notoriously slow owing to the system order and amount of time-varying components. A common approach to reduce simulation run-time is to partition power systems using Bergeron's travelling-wave model and to simulate the subsystems on a distributed computer. In this study, power systems are partitioned using a new mesh tearing approach, and the subsystems distributed across the cores of a quad-core computer. A notional shipboard power system model was partitioned using the proposed partitioning approach, which is used to show how the simulation run-time reduces as a function of the number of partitions and number of power converters.