Study of Gray Code Implementation for Single Phase Inverter Short Circuit Protection

Inan electronic circuit, short circuit protection can be done by using passive and active method. The active method is usually using current sensor and/or thermo sensor while the passive method is using trigger design for power circuit such dead time delay trigger or digitally interlock trigger for high side and low side. Dead time delay method can increase the total harmonic distortion (THD) while the interlock method must add more components. This paper discusses the design of Gray code for passive short circuit protection. Gray code is widely used in the field of communications technology, mechanical engineering, and digital data processing because the Gray code can minimize errors. The Gray code converts an integer value, represented as a voltage, into a series of pulses in digital form. In inverter design based on microcontroller, calculations to generate AC modulation is done in the microcontroller. This increases programming complexity and amount of coding downloaded to the microcontroller chip while the capacity of the flash memory in the microcontroller is limited. In turn, this makes program execution time is longer. This paper discusses the design of a single phase inverter using unipolar method with modulation of the sine wave and the triangular wave is done outside the microcontroller using data processing software application (Microsoft Excel) and short circuit protection using gray code modulation.