Consensus-based power balance control strategy for standalone power systems in machining parks considering CNC machine tool load characteristics

To address source-load power imbalance, frequency deviation, voltage fluctuation, and uneven power sharing among multiple grid-forming inverters during the standalone operation of a machining park, a consensus-based power balance control strategy considering the load characteristics of computer numerical control (CNC) machine tools is proposed. First, a refined CNC machine tool load model that represents time-varying torque and active and reactive power fluctuations is established by incorporating the dynamic characteristics of spindle motors and step changes in cutting loads. Then, consensus-based secondary control is introduced into droop control, and sparse communication between adjacent power supply units is employed to generate frequency-active-power and voltage-reactive-power compensation signals, thereby achieving frequency restoration, capacity-proportional active power sharing, and coordination between voltage restoration and reactive power sharing. Finally, a parallel power supply system comprising multiple grid-forming inverters is constructed to simulate cutting-load variations, power supply unit disconnection, and communication link failures. Simulation results demonstrate that the proposed strategy restores system frequency, improves voltage regulation and reactive power sharing, achieves capacity-proportional source-side power sharing, and maintains the dynamic active power balance between sources and loads.