Research On Generation Control System Of Wave Energy Cluster Harvesting

As a clean,pollution-free renewable energy,wave energy is widely distributed and has rich reserves.The development and utilization of wave energy is an inevitable requirement of the national development strategy.It will also be an important part of the future energy structure.Wave energy has a higher power density,and its average density is higher than other renewable energy such as solar energy and wind energy.However,due to the problems of wave like instability,intermittentness,and uneven distribution.There are problems of low efficiency and low utilization rate of wave energy collection and secondary utilization,which restricts the harvest and application of wave energy.Micro-grids can integrate multiple distributed energy sources,such as wave energy,to optimize the use of wave energy.In this paper,based on DC microgrid,the following researches are carried out on the power generation control system of wave energy cluster harvesting:Firstly,according to the characteristics of wave motion,a direct-drive generator is used to extract wave energy,which improves the energy conversion efficiency.Modeling the wave motion and direct drive generator,then simulating the wave energy extraction to get the output characteristic curve.The conversion of the collected AC power to DC power by connecting an uncontrollable rectifier is the prerequisite for subsequent access to the DC bus.Secondly,due to the unevenness and randomness of the wave motion,the instantaneous output power of the wave energy generator fluctuates accordingly.And it is not suitable to directly connect to the bus.For this reason,a strategy is proposed,which can use the charge and discharge characteristics of supercapacitors to connect with wave energy generators and form a unit with wave energy generators.When the output of wave energy generators is insufficient,the energy output is compensated.Conversely,it will absorb energy and stabilize the power output of the unit.Ultimately,it is verified by simulation that a single unit can meet the stable power output under power fluctuation conditions.Then,under the condition that a single unit runs smoothly,a multi-unit collaborative control strategy is proposed.This strategy satisfies the requirements of development and guarantees the simultaneous output of multiple units.And the information is exchanged according to the multiunit network topology to obtain each real-time energy state of the unit.Its output is dynamically allocated,so that the unit with a higher energy level has higher output power,and ultimately achieves the consistency of the energy state of multiple units.Finally,a physical system is constructed based on the structure of the wave energy power generation array.A rotary motor is used to drag a linear motor to simulate the movement of the float up and down in the waves to drive the mover to extract the wave energy.The DSP is used as the main controller and the model-based design method is used to carry out physical experiments on the above control strategies and systems,which verifies the effectiveness of the control strategies and systems.