Modeling And Experimental Study Of Active Heave Compensation System With Secondary Control

With the development and utilization of marine energy and resources,people put forward more stringent requirements for the compensation accuracy,energy efficiency and safety of the active heave compensation system of marine lifting and hoisting equipment.Compared with other active heave compensation systems,the secondary control active heave compensation system has significant advantages in compensation accuracy,energy recovery and reuse,and reduction of installed power,but the current domestic research relies on imported core components,which is still in the exploratory development stage,and there is still a lack of systematic theoretical research on engineering practice.In this paper,the SCAHC system is taken as the research object,and the mathematical model and simulation model of the system and the secondary control unit,which is the core component,are established.The correctness of the simulation model and the feasibility of the multi-feed-forward compensation cascade control strategy to achieve high-precision heave compensation are verified by experiments.The main research of this paper is as follows:1.The mathematical model of SCAHC system is established based on the working mechanism.Firstly,the main structure and working mechanism of SCAHC system are analyzed,and the mathematical logic relationship and energy transfer relationship between the main components are revealed according to the mechanism,and the mathematical model of the system is established.Taking the amplitude margin and phase margin as the stability index,the closedloop control strategy of the system is analyzed and determined.2.Based on the mathematical model,the simulation model of SCAHC system is established.According to the mathematical logic relationship and energy transfer relationship between the units and components,the simulation models of the main physical units are established in the AMESim simulation platform,and the simulation models of the control units are established in the Simulink simulation platform,thus forming the overall simulation model of the SCAHC system.3.The correctness of the SCAHC system simulation model is verified based on the test.According to the idea of "first subsystem,then overall system",the main unit performance test and the overall system performance test are carried out step by step,which verifies the correctness of the SCAHC system simulation model,and the overall performance reaches more than 95% of the simulation accuracy.4.Based on the validated SCAHC system simulation model,the influence of the main parameters on the system control characteristics is revealed.At first,that optimization goal of the system control characteristic is analyzed,and the main parameter affecting the optimization goal are summarized.Then,the main parameters control characteristic are analyzed by using the validated SCAHC system simulation model,and it is concluded that reducing the dead angle of the valve plate in the secondary unit in the drive unit will obviously improve the low-speed characteristics of the secondary unit;Increasing the total moment of inertia of the secondary unit,reducer and winch drum in the actuating unit will lose part of the rapidity and improve the lowspeed characteristics and zero-crossing characteristics of the secondary unit.In a word,the simulation model which can reasonably reflect the characteristics of SCAHC system and its main units is established in this paper,and the influence law of the main parameters on the system control characteristics is summarized,which provides a theoretical basis for the analysis,modeling and test of the secondary control unit,and lays a foundation and provides theoretical help for the independent development of domestic SCAHC system.