Evolving grid code requirements and regulatory standards, e.g. in Sweden and Lithuania, increasingly demand that Wind Power Plants (WPP) shall be capable of contributing with damping of power oscillations in the grid, typically induced by fluctuations of rotor speed among synchronous generators interconnected. In general, those Power Oscillations Damping (POD) requirements require a damping effect in the range of 0.1-2.0 Hz. Previous work has elaborated on the challenges and opportunities for WPPs to offer POD function as service to the grid. It was shown the success of a POD function depends on the Observability and Controllability of the electromechanical oscillations at the Point of Connection (PoC) of the WPP with the grid. In this article, a solution concept for POD function in WPPs, its real scale field tests results and simulations validation are presented. This POD function is based on the modulation of the exchanged Reactive Power (Q) at the PoC in response to the oscillations of the RMS Voltage (V) observed at the PoC, namely POD-Q. It is known that this concept can contribute with a positive damping effect to the power oscillations; additionally, it can prevent a destabilizing effect from voltage control. The selected input and output signals in POD-Q function and their coordination in terms of gain and phase shift provide satisfactory damping performance. The required phase shift can be characterized in the frequency domain by a Bode Diagram of Q(V) showing the gain and phase shift for a range of frequencies. Ideally the right phase shift for the damping effect is Q modulation lagging V oscillations at the PoC in the range -90 to -180 degrees. This type of assessment is aligned with some TSO grid code requirements. Previous work has shown field test results of the closed-loop performance of the POD-Q controller using the actual V as input signal. In this article, additional field test results in real scale wind plant during commissioning show the open-loop performance of POD-Q controller, fulfilling the phase shift and grid code requirement. Besides the progress and maturity to achieve such goal in WPPs control designs, it is also crucial that such capabilities are transferred into the electrical models of these WPPs so that these phenomenon and mitigation function can be assessed through dynamics simulations studies. Requirements for validating the POD function also involve using electrical simulation models provided by the Original Equipment Manufacturers (OEMs) to ensure effective attenuation of power oscillations. This process includes creating undamped oscillations and measuring damping performance with and without the POD-Q function and it is crucial to validate against site measurements to ensure reliability of such models. Additionally, Vestas presents the results of employing an electrical simulation model to validate the POD-Q function of their WPPs and elaborate on validation best practices and success criteria. Based on field tests results from dedicated WPP and various test cases, the validation process involves comparing simulation results with field measurements, assessing phase shifts and the amplitude of voltage and reactive power signals. The findings demonstrate that if correctly modelled, the POD-Q function effectively attenuates power oscillations, with simulation results closely matching field data. This validation ensures the reliability of Vestas' electrical models, contributing to stable and compliant grid operations.