*Supercapacitors: The Innovation of Energy Storage DOI: http://dx.doi.org/10.5772/intechopen.106705*

problems on individual cells. The first problem is solved by connecting several series strings in parallel, and the second by passive (cheap and bad) or active (expensive and excellent) voltage balancing.


In an asynchronous motor, at a constant frequency and amplitude of the supply voltage, the rotor speed depends on the load moment, which requires complicated control algorithms in cases where precise speed and/or position control is required. This phenomenon is a consequence of the principle of operation of an asynchronous motor, which is electromagnetic induction and requires a difference in speed between the rotor and the rotating magnetic field generated by the stator in order for the electromagnetic torque to exist. The electronics that realize the aforementioned algorithms were expensive, therefore, it made it difficult to use asynchronous motors for such purposes. However, today, with the low cost of electronic components and the use of computers in the realization of regulation algorithms, they are increasingly used.

The introduction of supercapacitors and power electronics assemblies based on DC voltage interfaces lead to a significant improvement in the performance of electric vehicles, such as acceleration, use of braking energy, and reduction of dimensions. Blocks of high-power supercapacitors are now also installed in large vehicles (buses and rail vehicles). In **Figure 32** a complete green energy system is presented, where supercapacitors play an important role.

**Figure 32.** *Green transport [63].*
