作为未来智能配用电系统的重要组成部分，直流微电网具有能量转换效率高、能量传输密度大、不存在无功功率流动和并网同步等优势。然而，恒功率负载(Constant power load，CPL)因其负阻特性，会对直流微电网的稳定性产生不利影响，造成系统电压振荡。因此，带恒功率负载的直流微电网稳定性问题成为研究热点，已有的直流微电网稳定性研究主要针对单极性直流微电网，而针对双极性直流微电网的研究缺少系统论述。本文以单极性与双极性直流微电网为研究对象，首先，分析带恒功率负载的直流微电网稳定性。然后，对目前直流微电网的稳定性判据进行归纳，分析其研究趋势。在此基础上，针对恒功率负载引起的稳定性问题，从源变换器输出阻抗和负载变换器输入阻抗两个角度出发，对现有的控制方法归纳总结，并将现有的控制方法总结归纳为有源控制方法和无源控制方法。最后，对带恒功率负载的双极性直流微电网稳定性问题研究方向进行了展望。
DC microgrid stability control with constant power load:a review
The DC microgrid has the advantages of high energy conversion efficiency,high energy transmission density,no reactive power flow,and grid-connected synchronization.It is an essential component of the future intelligent power distribution system.Constant power load(CPL)will degrade the stability of the DC microgrid and cause system voltage oscillation due to its negative resistance characteristics.As a result,the stability of DC microgrids with CPL has become a problem.At present,the research on the stability of DC microgrid is mainly focused on unipolar DC microgrid,while the research on bipolar DC microgrid lacks systematic discussion.The stability of DC microgrid using CPL was studied first,and then the current stability criteria of DC microgrid were summarized,and its research trend was analyzed.On this basis,aiming at the stability problem caused by CPL,the existing control methods were summarized from the perspective of source converter output impedance and load converter input impedance,and the current control methods were outlined as active and passive control methods.Lastly,the research path of bipolar DC microgrid stability with CPL was prospected.
constant power load(CPL)DC microgridvoltage balancerstability criterioncascaded systemvirtual resistance
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