Renewable energy sources (RES), particularly wind power and solar photovoltaic (PV), are experiencing high growth worldwide during the last decades in a row, which has been pushed to now account for a third of global power capacity. With the continuous reduction on the cost of RES and strong environmental protection pressure, many countries/regions are planning to integrate the high penetration of wind power and solar PV into the traditional power grid. With this effort, large-scale RES are technically pooled together among wide area grids geographically dispersed and then transmit them to load centers located far away onshore. Such transition from the traditional power system to high renewable penetrated grid challenges the state-of-the-art research in the circuit and system. The dynamic characteristics of traditional power grid are governed by large synchronous generators with substantial inertia. However, the growing integration of RES can alter the system characteristics with the dominant adoption of electronic power converters in fast response but less inertia. Power converters are commonly equipped with control system in a wide-timescale for regulating the current and exchanging power with the power grid. The widetimescale control dynamics of converters can result in cross couplings with both the electromechanical dynamics of electrical generators and the electromagnetic transients of power networks, leading to oscillatory stability across a wide frequency range. A number of incidents have been reported due to the grid integration of renewable energy, e.g., 250 Hz oscillation in BARD Offshore 1, Germany, in 2013, and also sub-/super-synchronous oscillations in the wide-timescale in Xinjiang wind farms, China, in 2015, where the undesired harmonics, inter-harmonics, or resonances caused disruption to the power generation and transmission. All these urge us to re-examine the dynamic behavior about high renewable penetrated power system that have been overlooked from a conventional view."