Abstract: A high voltage battery system can receive power from an AC grid and deliver power to a low voltage battery system. Embodiments can include an active filter and high voltage to low voltage (HVLV) DCDC converter to reduce harmonics associated with the charger reaching the low voltage battery system and further to stabilize the voltage presented to the HVLV DCDC converter to improve its operating efficiency.

Abstract: A switching system can include a main switching device configured to switch a voltage, a gate driver having an output coupled to a drive terminal of the main switching device and configured to deliver a drive signal to the main switching device, and a clamp circuit. The clamp circuit can be coupled to the drive terminal of the main switching device. The clamp circuit can include a logic gate configured to drive a clamp switching device coupled to and configured to clamp a voltage at the drive terminal of the main switching device. A drive signal of the clamp switching device can be substantially complementary to the main switching device drive signal. The logic gate can provide at least a portion of a delay between switching transitions of the main switching device and switching transitions of the clamp switching device.

Abstract: A high voltage battery system can receive power from an AC grid and deliver power to a low voltage battery system. Embodiments can include an active filter and high voltage to low voltage (HVLV) DCDC converter to reduce harmonics associated with the charger reaching the low voltage battery system and further to stabilize the voltage presented to the HVLV DCDC converter to improve its operating efficiency.

Abstract: A charger for a battery power system can include first and second switching bridges with inputs couplable to an AC source, at least one transformer having two or more primary windings (connected in series and coupled to the switching bridges) and at least two secondary windings, and second rectifier/chargers, each coupled to at least one of the secondary windings and couplable to at least one battery. The switching bridges may be respectively operable during positive and negative half cycles of the AC source to deliver an AC voltage to the transformer. The rectifier/chargers may be operable in a first mode to receive an AC voltage from the transformer and deliver a DC voltage for charging the respective battery. In some multi-battery embodiments, the rectifier/chargers may also be operable in a second mode to deliver an AC voltage from a respective battery to the transformer to balance charge between the batteries.

Abstract: A switching system can include a main switching device configured to switch a voltage, a gate driver having an output coupled to a drive terminal of the main switching device and configured to deliver a drive signal to the main switching device, and a clamp circuit. The clamp circuit can be coupled to the drive terminal of the main switching device. The clamp circuit can include a logic gate configured to drive a clamp switching device coupled to and configured to clamp a voltage at the drive terminal of the main switching device. A drive signal of the clamp switching device can be substantially complementary to the main switching device drive signal. The logic gate can provide at least a portion of a delay between switching transitions of the main switching device and switching transitions of the clamp switching device.

Abstract: A switching system can include a main switching device configured to switch a voltage, a gate driver having an output coupled to a drive terminal of the main switching device and configured to deliver a drive signal to the main switching device, and a clamp circuit. The clamp circuit can be coupled to the drive terminal of the main switching device. The clamp circuit can include a logic gate configured to drive a clamp switching device coupled to and configured to clamp a voltage at the drive terminal of the main switching device. A drive signal of the clamp switching device can be substantially complementary to the main switching device drive signal. The logic gate can provide at least a portion of a delay between switching transitions of the main switching device and switching transitions of the clamp switching device.

Abstract: Systems and methods for power conversion are described. Symmetric topologies and modulation schemes are described that may reduce common-mode noise. For example, a system may include a transformer including a first secondary winding and a second secondary winding; a rectifier, including a set of switches, that connects taps of the first secondary winding and the second secondary winding to a first terminal and a second terminal, wherein the rectifier is symmetric with respect to the first secondary winding and the second secondary winding; a battery connected between the first terminal and the second terminal; and a processing apparatus that is configured to control the set of switches to rectify a multilevel voltage signal on the transformer, including: selecting a modulation scheme from among two or more modulation schemes based on a measured voltage level of the battery.

Abstract: Systems and methods for power conversion are described. Symmetric topologies and modulation schemes are described that may reduce common-mode noise. For example, a system may include a transformer including a first secondary winding and a second secondary winding; a rectifier, including a set of switches, that connects taps of the first secondary winding and the second secondary winding to a first terminal and a second terminal, wherein the rectifier is symmetric with respect to the first secondary winding and the second secondary winding; a battery connected between the first terminal and the second terminal; and a processing apparatus that is configured to control the set of switches to rectify a multilevel voltage signal on the transformer, including: selecting a modulation scheme from among two or more modulation schemes based on a measured voltage level of the battery.

Abstract: Aspects of the present disclosure involve a system and method for providing a boosted voltage using a single stage dual active bridge converter. In one embodiment, the single stage dual active bridge converter is introduced for high voltage charging using phase shift and frequency control. Phase shift and frequency control can be implemented on duty cycled switches and pulse width modulated switches in order to achieve a desired output voltage. In another embodiment, the phase shift and frequency controlled single stage dual active bridge converter is replicated in modular form to provide a single-phase system that provides a voltage for charging a high voltage system. In yet another embodiment, the phase shift and frequency controlled single stage dual active bridge converter is replicated in modular form to provide a three-phase system that provides a voltage for charging a high voltage system.