How to ensure efficient and stable DC current for green hydrogen
Figure 6: An active rectifier replaces the diodes or thyristors in the rectifier circuit with IGBTs, which are switched by a gate driver controller. (Image source: Infineon Technologies)
It is rated to handle 1700 V with a maximum collector current of 1700 A. The circuit shown in Figure 6 would use three such modules. An IGBT gate driver such as the 1ED3124MU12HXUMA1 turns a single IGBT pair on and off. The gate driver is galvanically isolated using coreless transformer technology. It is compatible with IGBTs having voltage ratings from 600 to 2300 V, and has a typical output current of 14 A on separate source and sink pins. The input logic pins operate on a wide input voltage range from 3 to 15 V using CMOS threshold levels to support 3.3 V microcontrollers.
Unlike a traditional rectifier, which produces non-sinusoidal line currents, an active rectifier has an inductor in series with the IGBTs that keeps the line current sinusoidal and reduces harmonics. The impedance of the IGBT when conducting is very low, which reduces conduction losses and improves efficiency compared to a standard rectifier. An active rectifier controller maintains a unity PF, so external power factor correction (PFC) devices are unnecessary. It also operates at higher switching frequencies, resulting in smaller-sized passive components and filters. The FF1700XTR17IE5DBPSA1 combines dual IGBTs in a half-bridge configuration in a PrimePACK 3+ modular package.
Power conversion for DC sources Separating hydrogen using DC power sources such as photovoltaic energy and battery-based hybrid systems requires DC/DC converters. As noted earlier, these converters can improve the performance of diode/thyristor rectifiers. They also permit the optimization of local DC grids for plant flexibility. The interleaved buck converter uses half-bridge chopper modules in parallel to change the DC level from the input to the output (Figure 7). With proper interleave control, this DC/DC converter topology significantly reduces DC ripple without increasing the inductors' size or switching frequency. Each
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