The task in my degree dissertation is the progression, construction and activation of an ultra fast "HIGH-VOLTAGE-BREAKER" (UFHVB/UFHSD) with metal oxide semiconductor field effect transistors.
The photo collection at the bottom of this site show the complete high-voltage-breaker. In the 19"-case are three electronic boards, which steers and turns the voltage. The total switch-device consists about 95% of electronic components.
The funktion tests of the complete device work very accurate and switch the lightning impulse voltage 1,2/50 of 5000V (DC) without compunction.
The theoretical values for the "HIGH-VOLTAGE-BREAKER" is for example:
7200V (DC) and 125A for the time of 80ns with a duty cycle "D" of 0.01 = 1%. The thermical condition istn´t to go beyond the pale.
The total switch time is dependent of the current. Another value of current make a mathematical computation absolutely essential (look at the "maximum effective transient thermal impedance, junction-to-case vs. pulse duration-diagram" of the MOSFET "APT12040L2FLL"). So, it´s a very elaborate system with many know-how.
An impulse-device produce the lightning impulse voltage 1,2/50. The "HIGH-VOLTAGE-BREAKER" and replace the spark-gap into the circuit.
Many knowledge in digital-,analog- and power electronics play an important part. Of course, specific applications in the high voltage engineering and technology is vitally important, too.
The electronic devices use the new professional technology of microcontrollers.
The microcontroller is a completive very small computer include many functions and features. Each one has a separate memory, central processing unit resp. arithmetic and logic unit, interface and much more. The new generation of microcontrollers shows more and more new functions, features and designs in a small package chip.
An eight-pin integrated circuit (IC) is the AVR 8-Bit RISC-Device ATtiny13 by Atmel, which is an important consideration by the UFHVB. The chip has much options, that you have a problem to use all the limited opportunities together.
If you definitely need support or more information about the microcontroller, you can look at the page www.atmel.com . If you want order a chip for low cost, look at the distributors.
In the High-Voltage-Laboratory of the South- Westphalia University of Applied Sciences -location in Soest/Germany-, I´ve construct a pulse-device, which produce the standard lightning impulse voltage (1,2/50).
The pulse-device is very important for my diploma thesis, because I need the impulse for tests.
At first I´ve use a spark gap in testing phase. The digital oscilloscope show an impulse-voltage with a front-time of 1,2 µs and a back halftime of 50 µs.
The times (1,2 µs and 50 µs) have a very minimal slight difference from the nominal fixed values, so I can use the impulse without hesitation. It`s fair to say that the pulse-device work very accurate.
Very important is the range of the construction by electronic components. The values of the components are measure and calculate directly, so that the pulse-device get a fine-tuning. Of course, the knowledge about the lightning impulse voltage (1,2/50) is hugely important, too.