Many active power control strategies have been studied in the wind farm to distribute the power set-point for each unit under the power limitation mode. Ref. [7] proposed a two-time-level wind farm active power control to improve the wind power output, where a distributed model predictive control strategy is introduced and ADMM (Alternating Direction Method of Multipliers) algorithm is used to speed up the solution process. Refs. [8; 9] proposed a wind farm distributed model predictive control with clustering-based piece-wise affine wind turbine model on the basis, complete wind turbine model is used and the wind farm is set to track the active power output as the conventional strategy while reducing the wind turbine loads. Another farm control load-reduction strategy is introduced in [10], of which the power tracking error and loads' conditions are combined in the cost function and solved by a centralized model predictive controller. When the wind farm is connected into the power grid, voltage will be an important parameter that needs to be considered. Ref. [11] proposed a VSC-HVDC (Voltage Source Converter based High Voltage Direct Current Transmission) connected wind farm active power control when the voltage variation is taken into consideration to improve the wind farm voltage performance. Since WTGSs in a wind farm are growing in number, the optimization problem from the wind farm level will also increase in orders and the solving time required. In such a case, the decentralized strategies are also used in wind farm power and voltage control process. The related research can be referred to from [12; 13]. As an important part in electric power grid, the wind farm is also controlled to support the peak and frequency for the electric power grid. According to the time scale, the frequency regulation of power system is mainly divided into different levels [14]. In the primary frequency regulation (PFR), the power generation unit takes the power system frequency error as the input, and the unit power output is adjusted by the unit control system to maintain the power system frequency stabilized at the target. The secondary frequency regulation (SFR) is also marked as AGC (Automatic Generation Control), which controls the output power for different power generation units to meet the frequent changing power demand and keeps the power system under economic operations. The reviewed strategies in the above paragraph were focused on the wind farm AGC, while several other control methods like the _Droop Control_ and _Inertial Control_ are introduced in WTGS to involve wind energy in the PFR [15]. The kinetic energy stored in the WTGS rotor will be released under frequency drop conditions to support the grid frequency. A new wind farm PFR strategy is introduced in [16], firstly, the PFR strategy is first designed for one WTGS, and then the proposed strategy is implemented into the wind farm by the participation-factor-based wind turbine control strategy. In this way, the wind farm under the proposed strategy could have the PFR ability while avoiding individual turbine control. Although the previously strategies are useful and efficient, there still exist several potential parts which can be further improved in detail. Firstly, a wind farm level exists to arrange all the WTGSs according to the geographical location, and the power control and frequency regulation can be controlled and optimized on the wind-farm level. The increase in number of WTGSs in the wind farm may cause calculation problems during optimization. For higher reliability, a wind-turbine cluster level can be selected as a middle layer between the single wind turbine and wind farm level to control and optimize the wind turbine active power output. Secondly, in the industrial field, it is difficult for the wind turbine to output all the available power due to the power set-point for the cluster or wind farm is usually lower than its available power.