No abstract

To aim at the defects of the traditional VSG (virtual synchronous generator) control schemes to only complete the primary frequency regulation equivalent to droop control, and not to realize the secondary frequency regulation, this paper proposes a new control scheme to realize the secondary frequency regulation of the VSG, such that system frequency can return to the rated value. In this method, the torque change process of the rotor of synchronous generator is firstly analyzed when the system active power fluctuates. And then, a novel secondary frequency regulation control strategy of the VSG is proposed, where the small-signal model of power transmission of the VSG is established and transfer function is analyzed, and parameters design and stability analysis of the control system are conducted. Finally, simulation experiments show the correctness and effectiveness of the proposed method.

What are the photovoltaic properties of solar cell, the operating principle of DC/DC conversion, the overall scheme of MPPT as well as the algorithm of maximum tracking power point combine the actual situation of space power system, with the introduction of the modular MPPT algorithm. These aim to study how to improve the utilization efficiency of the field monitoring equipment about the solar-powered accumulator energy-saving control system for solar energy. Using solar power meter can detect changes curve of light intensity so as to obtain parameters for the simulation, and then we can establish the photovoltaic array simulation model to gain the three actual tracking power curves of the combined algorithm, the perturbation method and the incremental conductance method and stabilize the best output voltage of solar cells while using Buck Circuit to reduce voltage to charge for nickel-cadmium accumulator pack. As a result, the system can achieve the uttermost steady operation with the reliability improved. The design adopts the DC/DC boost circuit to providing charging system for battery and utilizes the DSP program to generate the PWM to track the maximum power output (MPPT). This system has the advantages of the simple circuit structure, the good waveforms and the accurate measurement result, which conforms to the design requirements.