| Contained in the islanding of distributed generation DC unit under the distribution network,due to the distributed generation unit affected by external factors is large,so that the power output of photovoltaic power generation has a certain volatility and randomness,this will cause the user to get the does not meet the continuity and reliability of power,therefore,in order to improve power supply reliability and power quality,you must configure the storage unit to DC power distribution system,and the reasonable control of the energy storage unit.First,the DC distribution network consisting of various modules analysis and research,gives the corresponding equivalent model and prove the correctness of the equivalent model herein are given in MATLAB simulation software.In order to obtain a more comprehensive load power rational allocation and utilization,the paper presents a fuzzy control algorithm based on high-pass filter power allocation policy change time constant,the control strategy through reasonable adjustments conducting high-pass filter time constant T,to for super capacitor and battery output power is corrected so that the charge state of the battery and super capacitor to fluctuate within a predetermined range.To make the system more reliable and stable operation,the paper uses a small mixing energy storage module based on bidirectional buck PWM signal model of complementary / boost converter;according to the battery to stabilize the low-power characteristics of the battery using a single current loop control,according to the super capacitor to stabilize the high frequency power fluctuations,super capacitor voltage-double loop open outer inner current loop control,and finally,in the MATLAB / Simulink software for simulation analysis of the algorithm,simulation results show that the control strategy not only to maintain the DC bus voltage stability,but also to optimize the battery charging curve,and battery life was extended. |
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