The Design For Distribution STATCOM Controller

With the progress of industrial technology,power load put increasingrequirement on electric energy quality.Electric power systems not only need to meetthe requirements of power capacity,but also need to face the increasingly complexload from load side,such as impact resistance、non-linear、unbalanced load,which areeasy to bring the problem of voltage instability、current distortion and negativesequence etc.Because of its perfect effects for power quality control,DistributionSTATCOM become the most popular control devices on power quality.Based on the analysis of the distribution static synchronous compensator worksand created a mathematical model,this paper studied the structure of the maincircuit.For the principle of improving compensation device safety、reliability、compensation capacity、harmonic suppression、accuracy and speed，a main circuitstructure of four interleaved PWM-VSI drive was proposed in this article and showthe detailed design process,the results show that the main circuit satisfies the abovedesign principles, which greatly improves the performance of the compensationmeans and has obvious advantages.At the same time a intelligent drive module2SD315A was used, which has short development cycle and collects drive, isolation,protection functions in one,finally,a comprehensive explain was showed.Comprehensive explain for the basic theory of the check method which is basedon original instantaneous reactive power theory was given.In order to improve thedetection speed and adaptability,this paper proposed FBD detection and improvedFBD detection method.By comparing,this method is not only simple withoutcumbersome coordinate transformation, and also the detection result still remainaccuracy with unbalance load in simulation experiments.Control strategy is the key of improving the performance of the distributionSTATCOM compensation.The paper first studied the device、the system controlmethod and used a PWM control on device、direct current control on system aftercomparative analysis.PI controller is the most critical member of the controller inthe DSP28335+CPLD digital control system,based on the design of the PIcontroller with fixed parameters,improved it and introduced fuzzy control algorithmto enhance controller adaptive and robustness.Taking advantage of the particleswarm algorithm simple, rapid and better iterative optimization effect for the fuzzyalgorithm complex parameter optimization,the simulation confirmed that the modified PI controller has a huge promote on strengthen the immunity of DCvoltage stability and the response speed&accuracy of the compensating current.Finally, this paper developed the experimental device of D-STATCOM. Thepaper designed the devices hardware&software system and the experimentplatform,and also verified that the main circuit design、detection method and controlstrategies can improve the effectiveness of the compensation device compensationperformance.