隔离型交-直流固态变压器前后级协调控制

Coordinated Control of Isolated AC/DC Solid State Transformer

固态变压器(SST)广泛采用双向全控整流器与隔离型DC/DC变换器前后级级联结构,负载扰动时,线性化模型响应速度慢且级间电压动态波动变大,采用非线性控制中的功率预测控制策略对上述问题进行改进,并研究了SST前后级协调控制策略。最终提出基于功率预测间接前馈协调控制策略,将功率预测控制应用于两级级联系统并加入功率间接前馈协调控制实现对两级级联系统的协调控制,以改善系统动态性能和稳态性能。通过仿真和实验验证了功率预测间接前馈协调控制策略的优越性和可行性。

Solid-state transformers(SST) widely use bidirectional fully-controlled rectifiers and isolated DC/DC converters with front and rear cascade structures.When the load is disturbed,the response speed of the linearized model is slow and the dynamic fluctuation of the voltage between stages becomes large.The above problems are improved by the power prediction control strategy in non-linear control,and the coordinated control strategy of the front and rear stages of the SST is studied.Finally,an indirect feedforward coordinated control strategy based on power prediction is proposed.The power prediction control is applied to the two-level cascaded system and the indirect feedforward coordinated control of power is added to realize the coordinated control of the two-level cascaded system to improve the dynamic state performance and steady state performance of the system.The superiority and feasibility of the power prediction indirect feedforward coordinated control strategy are verified by simulation and experiment.