A form of DC-DC converter known as the dual active bridge (DAB) employs two active switches in each of its two bridges. High-power applications utilizing this kind of converter include electric vehicles, solar inverters, and data centers. We shall examine the DAB’s operation and its uses in this article.
A high DC voltage is changed into a low DC voltage, or vice versa, by the DAB. Two bridge circuits, each made up of two active switches and two passive diodes, are present in the converter. Typically, IGBTs or MOSFETs are used as the switches, and they are managed by a pulse-width modulation (PWM) signal.
The DAB works by sequentially closing one set of switches (S1, S2) before closing the other set (S3, S4). The input voltage is applied to the primary side of the transformer when the first set of switches is closed. The secondary side of the transformer is linked to the output voltage when the second set of switches is closed.
The DAB’s switching frequency normally ranges from 20 kHz to 100 kHz. The duty cycle of the PWM signal is adjusted to control the converter’s output voltage. It is possible to raise or lower the output voltage by altering the duty cycle.
Electronic circuits are designed using both RC and LC circuits. A series or parallel connection between a resistor and a capacitor makes up an RC circuit. A series or parallel connection between an inductor and a capacitor makes up an LC circuit. An RC circuit is used to filter high-frequency signals, whereas an LC circuit is used to filter low-frequency signals. This is the main distinction between the two.
To lessen the ripple on a DC voltage, an LC filter of the pi type is utilized. Two capacitors are linked from the input and output of the filter to earth, and an inductor is connected between the input and output of the filter. Because of the way the circuit diagram resembles the Greek letter pi, the filter is known as a pi filter.
A type of DC-DC converter called a phase-shifted full bridge (PSFB) makes use of two transformers and four active switches. The phase shift between the primary side voltages of the two transformers is controlled by the converter. The PSFB is appropriate for high-power applications because it can run at a high switching frequency. What precisely is a ZVS circuit?
A particular kind of DC-DC converter known as a zero-voltage switching (ZVS) circuit changes the active switches when the voltage across them is zero. The ZVS circuit boosts converter efficiency by lowering switching losses. High-power applications like electric vehicles, data centers, and renewable energy systems frequently employ the ZVS circuit.
In conclusion, a type of DC-DC converter called a dual active bridge is frequently employed in high-power applications. Each of the converter’s two bridges has two active switches that are used to drive it. RC and LC circuits, pi filters, phase-shifted full bridges, and ZVS circuits are further related concepts that are frequently employed in electrical circuits. Designing and implementing electronic systems requires an understanding of these ideas.
The Dual Active Bridge (DAB) converter uses two crucial ZVS and ZCS methods. Zero Voltage Switching, or ZVS, refers to the process of turning on and off the converter’s switches while the voltage across them is zero. This improves efficiency and lowers switching losses. In contrast, ZCS stands for Zero Current Switching, which denotes that the switches are activated and deactivated when there is no current flowing through them. Additionally, this method helps lessen electromagnetic interference and switching losses. Both methods are crucial for raising the DAB converter’s effectiveness and performance.
When the voltage across a power semiconductor device, such as a MOSFET or IGBT, is not zero before it is turned off, the switching action is referred to as hard switching. The device may experience significant voltage and current stresses as a result, which could result in increased power losses, decreased efficiency, and even device failure.