Distributed Control For ISOP Connected Inverter System And Its Redundancy Design

The power electronic integration technology is the gateway to further expand the fields of power electronics applications.The ISOP composite system,of which the standard module is inverter,is taken as an example to study.There are two main goals: One is to realize the power equalization and complete equivalence between modules in the system.The other one is to improve the fault tolerance and redundancy of the system.For the selection of standard modules,the two-stage topology should be adopted as the inverter module.With the goal of high frequency,the basic selection criteria for the DC/DC topology are given.And the original topology is improved to prevent circulating current,which is the output of the second stage is connected by inductance in parallel to enhance the symmetry and balance between modules.Because the output of the ISOP inverter system is AC,it is necessary to control the active power sharing and the reactive power sharing.So in addition to controlling the input voltages sharing,the output power factor angles of each module are required to equal.At the same time,in order to implement distributed control and provide foundation for fault tolerance,the distributed bus frameworks are established.The relationship between the input voltage sharing loop and the output voltage loop is analyzed,and several proofs that have certain universality is given.It is proved that these two loops are decoupled and they can be designed independently;The input voltage sharing loop is designed to introduce the positive resistance for the input terminal,which is to ensure that the equivalent impedance of the input is positive;It is proved that the ISOP inverter system has the equivalent transfer function with the output voltage loop of each module,which is the current sharing capability.Finally,the control strategy is proposed for the ISOP inverter system.The method is based on the Middle Brook impedance criterion,and the interaction is considered.And the experiment with the prototype proves the feasibility of the control strategy.The study of the ISOP inverter system,enriches and develops the idea and concept of power electronic system integration.And the basic method can be extended to other forms of energy transformation.At the same time,it also makes the foundation for the farther application of power electronics integration technology.