**5. Conclusion**

The configuration shown in Figure 20(a) is characterized by having a gearbox. The wind tur‐ bine system with a SEIG and full rated power electronic converters is shown in Figure 20(a). Multipole systems with the permanent magnet synchronous generator without a gearbox is

**Figure 21.** a) output regulated voltage of DC/DC boost converter. (b) output AC voltage and current of DC/AC 4 levels

The grid connected 1 KW small scale wind generation system has been modelled, designed and implemented in renewable energy research center of sahand university of technology. In this project the maximum power point tracking method has been used to control of varia‐

FCMC. (c) output AC voltage and current of DC/AC 5 levels FCMC [23].

shown in Figure 20(b).

332 Advances in Wind Power

This chapter has reviewed different power electronic converters for small-scale wind turbine systems. Various arrangements of small scale wind generators with different generators and control systems are described. In compare with gearbox-connected wind generators, the main advantages of direct–drive wind generator systems are higher overall efficiency, relia‐ bility, and availability due to omitting the gearbox. Considering the improved performance and reduced cost of PM materials over recent years, direct drive PMSG have gained more attention in small scale wind generation systems. Different types of DC/DC converter for small-scale wind turbine output voltage regulation are described.

Several topolgies of DC/AC inverter for DC/DC converter output voltage conversion are in‐ vestigated. The most significant advantages of multilevel converters in comparison with two-level inverters are low harmonic contents, low output *dv dt* and electromagnetic interfer‐ ence, and reduced size of filter inductance. Even though all types of multi-level converters such as DCMC, CMC, and FCMC present major advantages for small-scale wind energy conversion applications, but FCMCs have gained more attention in small-scale wind energy conversion systems.

Two most used solutions with full-scale power converters are investigated. Since the generator is decoupled from the load by a dc link, so both solutions have almost the same controllable characteristics. The wind turbines with a full scale power converter between the generator and load give the extra technical performance. The provided ex‐ perimental results verify the good performance and feasibility of the proposed fullscale power electronic converter.
