Structure and operation of the voltage converter of the turbo generator installation
This article discusses the structure and principle of operation of a voltage converter of a turbo generator installation that operates at high speeds (6000 rpm) and generates output voltage at a frequency of 50 Hz, approaching a sinusoidal form.
Input phase of the frequency converter
At the initial stage of operation, the frequency converter creates a three-phase system with a striking voltage, thanks to two high-frequency generator devices (300 and 400 Hz). The sinusoidal component of the operating voltage has a frequency of 50 Hz, while the filling frequency is 350 Hz.
However, spectral analysis shows that the operating voltage contains only frequencies characteristic of sources with frequencies of 300 and 400 Hz; frequencies of 350 and 50 Hz are absent.
Structure of the converter
At the input of static type phase converters, the use of a frequency converter is envisaged to form the output voltage based on sinusoidal supply voltage. In this case, the load connected to the power source interacts with the converter through open-type switches.
During design, various reversible type circuits controlled by rectifier devices are used.
Hardware solutions of the frequency converter
The frequency converter operating scheme works due to significant currents with high derivatives, causing significant induction. Consequently, voltage, current, and other analog signal sensor boards with sequential transmission channels over a fiber optic network have been developed. This allows placing sensors at any point in the converter and transmitting data over long distances without interference.
Design features of the frequency converter
The system consists of four transistor modules that form one arm of the frequency converter, mounted on a cooler. A total of nine blocks are placed in the frequency converter, each equipped with snubber capacitors, drivers, and temperature sensors of the cooler.
An output LC filter is used to reduce the distortion coefficient of the output voltage.
Quick-disconnect fittings and CBI couplings from the Staubli company are used to connect the cooling circuit with liquid, allowing easy disconnection of the block from the liquid circuit.
Conclusions
Currently, work is ongoing to improve the control algorithms for the low-frequency frequency converter and increase the power of the generation system. New methods for creating an input voltage are being considered in order to obtain a high-quality output.
Summary
An unconventional static electricity converter with direct connection has been created, which can provide a high-quality output voltage curve and facilitate reactive power exchange between the load and the generator using modern control algorithms and power valves.