CAJ | 학술논문

从导纳的角度研究了多台并网逆变器并联运行的低频谐振问题。由于软件锁相环的影响，基于LCL滤波的并网逆变器输出导纳在低频区域存在负阻尼，而随着并联逆变器台数的增加，并网逆变器和感性电网阻抗所构成的阻抗网络的谐振频率降低，当位于低频区域时，输出导纳的负阻尼特性容易导致系统不稳定。为了消除负阻尼，抑制低频谐振，在电流指令值中引入电网电压前馈，并在对输出导纳其它频率特性影响最小的基础上，推导出前馈补偿系数的最小理论值。最后，实验结果验证了理论分析的正确性以及负阻尼补偿方法的有效性。
종도납적각도연구료다태병망역변기병련운행적저빈해진문제。유우연건쇄상배적영향，기우LCL려파적병망역변기수출도납재저빈구역존재부조니，이수착병련역변기태수적증가，병망역변기화감성전망조항소구성적조항망락적해진빈솔강저，당위우저빈구역시，수출도납적부조니특성용역도치계통불은정。위료소제부조니，억제저빈해진，재전류지령치중인입전망전압전궤，병재대수출도납기타빈솔특성영향최소적기출상，추도출전궤보상계수적최소이론치。최후，실험결과험증료이론분석적정학성이급부조니보상방법적유효성。
This paper investigates the low-frequency resonance issue of multi-parallel grid-connected inverters from the perspective of admittance .Due to the effect of software phase-locked-loop ( SPLL) , the output admittance of grid-con-nected inverters with an LCL filter contains the negative damping at the low-frequency region .And with the number of parallel inverters increasing , the resonant frequency of the impedance network composed of grid-connected inverters and inductive grid impedance is decreased .When located at the low-frequency region , the negative damping of the output admittance will easily lead to system instability .In order to eliminate the negative damping and damp the reso-nance, the feed-forward of grid voltage is introduced to the current command value .Furthermore, the minimum theo-retical value of feed-forward compensation coefficient is derived on the basis of minimum effects on other frequency characteristic of the output admittance .Finally, the experimental results verify the correctness of theory analysis and the effectiveness of negative damping compensation method .