This graduation theses shows some of possible versions of outdoor switchgears with very high voltage, especially on the level 123 kV both concerning own complement of classic outdoor switchgears with devices as are overvoltages limiter, disconnecting switchgears, circuit breakers, etc., and compact connections. In the introduction of my theses there are explained basic ideas and theories of switchgears and described main devices and equipments which create classic (from equipment setting point of view) outdoor switchgears of very high voltage. Subsequently it describes possible ways of linking-up of these devices in the complex of switchgears themselves according to possible dispositions arranged and busbars systems. The same focus is dedicated to new, non-classic (non-standard solution in terms of devices solution), compact solving of outdoor very high voltage modules either by air isolated or by means of enclosed technology with gas SF6 which represent innovative solving first of all from reduction of built up area point of view which is very important from economic point of view especially during constructions of new switchgears. In the end of my theses there are mentioned also brief evaluations of producers and economics for development and operation of individual technologies. I used for my work materials of companies CEZ, a. s., Siemens, a. s. and Abb, a.s.

Wound Field Synchronous Generators provide more than 95% of the electricity need worldwide. Their primacy in electricity production is due to ease of voltage regulation, performed by simply adjusting the direct current intensity in their rotor winding. Nevertheless, the rapid progress of power electronics devices enables new possibilities for alternating current add-ins in a more than a century long DC dominated technology. Damping the rotor oscillations with less energy loss than before, reducing the wear of the bearings by actively compensating for the mechanic unbalance of the rotating parts, speeding up the generator with no need for additional means, these are just few of the new applications which imply partial or total alternated current supplying of the rotor winding. This thesis explores what happens in a winding traditionally designed for the direct current supply when an alternated current is injected into it by an inverter. The research focuses on wound field salient pole synchronous machines and investigates the changes in the field winding parameters under AC conditions. Particular attention is dedicated to the potentially harmful voltage surges and voltage gradients triggered by voltage-edges with large slew rate. For this study a wide frequency band simplified electromagnetic model of the field winding has been carried out, experimentally determined and validated. Within the specific application of the fast field current control, the research provides some references for the design of the rotor magnetic circuit and of the field winding. Finally the coordination between the power electronics and the field winding properties is addressed, when the current control is done by means of a long cable or busbars, in order to prevent or reduce the ringing.

In neural implants and biohybrid research systems, the integration of electrode recording and stimulation front-ends with pre-processing circuitry promises a drastic increase in real-time capabilities [1,6]. In our proposed neural recording system, constant sampling with a bandwidth of 9.8kHz yields 6.73μV input-referred noise (IRN) at a power-per-channel of 0.34μW for the time-continuous ΔΣ−modulator, and 0.52μW for the digital filters and spike detectors. We introduce dynamic current/bandwidth selection at the ΔΣ and digital filter to reduce recording bandwidth at the absence of spikes (i.e. local field potentials). This is controlled by a two-level spike detection and adjusted by adaptive threshold estimation (ATE). Dynamic bandwidth selection reduces power by 53.7%, increasing the available channel count at a low heat dissipation. Adaptive back-gate voltage tuning (ABGVT) compensates for PVT variation in subthreshold circuits. This allows 1.8V input/output (IO) devices to operate at 0.4V supply voltage robustly. The proposed 64-channel neural recording system moreover includes a 16-channel adaptive compression engine (ACE) and an 8-channel on-chip current stimulator at 3.3V. The stimulator supports field-shaping approaches, promising increased selectivity in future research.