Power Electronics

The greatest power man has is the power of an imagination


Power electronics hardware

We design per request specific solutions for power conversion applications. With our hands-on experience in hardware design, both in terms of electrical specification and selection of components themselves, and in terms of mechanical design, we guarantee the best possible performance of each Kinestas product. The Kinestas team deals completely with thermal processes, design of power converters, and extensive experience with sensors used in power electronics as well as in peripheral design. Finally, each design is submitted to rigorous testing and verification.

Power converters control

For a particular converter to perform a specific function, for example, a battery charger, it is necessary to know how the converter is operated. In the case of a charger, how much voltage and current the charger needs to provide to properly charge the battery. It is necessary to know the dynamics of such a system as well as various control strategies that can be used. This control is done in 99% of the cases through microcontrollers. Therefore, it is necessary to know the physical model of the converter, which is then translated into mathematical / management model, and in the end, it all translates into embedded software programmed to the microcontroller/FPGA. For speeding up our control design and verification process, we rely on the HIL test bench (Hardware in the Loop).

Power semiconductor technology

The heart of an energy converter lies in power semiconductors. These include transistors, diodes and other components directly involved in energy conversion. SiC and GaN are new generation semiconductor technologies that are making significant changes in the industry. They enable greater efficiency and/or reduction of the converter dimensions. The main challenges of power semiconductors are related to their packaging, layout (including driving) and heat dissipation. Without this specific knowledge, it is impossible to make a good and reliable design.

Passive components

Another pillar of Kinestas competences is passive components, their optimization, and the effect on converter configuration. Passive components include capacitors, transformers and inductors. Why is this important? The reason is that over 50% of the volume and weight of the converter is dictated by the choice of passive components. As for transformers and inductors, the team has extensive practical experience in design and optimization. For example, for a given converter it is possible to make a huge number of different transformers that will provide the basic function, but depending on the desired goal, one design can be optimized in the direction of the least possible losses. The other can have the lowest cost, but it is very easy to get a combination where the transformer is both expensive and inefficient.

Circuit and FEM simulations

Today, this is a piece of very important knowledge in the field of virtual prototyping. In order to save money and time to market, in the initial design phase, the individual component, as well as the complete system, can be simulated in various tools. The traditional approach so far has been to make several prototypes during design until the final design is achieved, which requires enormous resources. A virtual design can easily check basic design parameters and performance. The simulations can be at the circuit level and are generally used by Spice simulators. For thermal processes, simulation is performed in FEM (Finite Element Method) tools. FEM is also used to design transformers and inductors.

System level optimization and integration

Finally, Kinestast team provides multi objective optimization, or system level optimization. With additional prototyping and zero series design we provide a full cycle of power electronics development. A good knowledge of system optimization methods is very important because it is different from the optimization of an individual component. Someone can make a transformer that has a minimum size, but as a result, the switching frequency must be increased, which will cause higher energy losses in the semiconductors, and therefore their temperature. This way, the size of the cooler must be increased and the starting benefit is immediately lost. Another direction related to this field is the integration of multiple systems into one. An example of this is an electric car. Today, the system is designed so that the electric motor and the inverter are separate systems. The trend is towards integration of inverters and motors which simplifies installation and the whole supply chain system. However, integration is not so simple, primarily because we have now combined the losses and heat generated by individual systems in one place, in other words, with even more heat concentrated in one place.