University of Florida Research Foundation Inc

Amirhossein Moeini

Shuo Wang

Hui Zhao

Systems and methods are configured to control DC side current harmonics of a cascaded H-bridge (CHB) converter that includes a plurality of cells. In various embodiments, an odd-order current harmonic is injected at the AC side of the CHB converter based on an optimization of a constrained optimization problem to achieve at least one of balancing the DC side current harmonics of the plurality of cells, reducing the DC side current harmonics of the plurality of cells, and meeting the requirements of the IEEE 519 standard. The optimization problem may include a cost function based on switching transitions of the CHB converter and at least one constraint based on, for example, an AC side current harmonic, a maximum demand load current of the CHB converter base on the IEEE 519 standard, and a zero-order current harmonic and an hth-order current harmonic for each cell of the CHB converter.

Cascaded H-bridge converters for battery energy storage systems

Techniques to diagnose internal short circuits (ISCs) of a lithium-ion battery (LIB) are disclosed. The short circuit resistance data can help to detect the ISCs of a LIB as fast as possible. For the proposed detection techniques, a resistor-based circuit and an inductor-based circuit are disclosed for single-cell LIBs as well as for LIBs having multiple cells. Two topologies of the resistor-based circuits are disclosed to detect the ISCs of multi-cell LIBs.

Fast and precise detection of an internal short circuit on a lithium-ion battery

A hybrid Cascaded H-Bridge (CHB) converter includes a selective harmonic current mitigation pulse width modulation (SHCM-PWM) unit coupled to an input current and providing an output signal SW, a phase shift pulse width modulation (PSPWM) unit coupled to the input current and providing an output signal SW, a modulation selector coupled to the output signal SWof the SHCM-PWM unit and the output signal SWof the PSPWM unit and providing an output signal SW, and a CHB converter coupled to the output signal SW of the modulation selector. The modulation selector can select one of the output signals (SWand SW) as the output signal SW based on the input current. The hybrid technique is for cascaded multilevel converters which utilizes asymmetric SHCM to mitigate the harmonics generated from PS-PWM to meet harmonic limits with a smaller number of switching transitions and smaller inductance than the conventional PS-PWM technique.

Control to output dynamic response and extend modulation index range with hybrid selective harmonic current mitigation-PWM and phase-shift PWM for four-quadrant cascaded H-bridge converters

A hybrid Cascaded H-Bridge (CHB) converter can include a selective harmonic current mitigation pulse width modulation (SHCM-PWM) unit coupled to an input current and providing an output signal SW, a phase shift pulse width modulation (PSPWM) unit coupled to the input current and providing an output signal SW, a modulation selector coupled to the output signal SWof the SHCM-PWM unit and the output signal SWof the PSPWM unit and providing an output signal SW, and a CHB converter coupled to the output signal SW of the modulation selector. The modulation selector can select one of the output signals (SWand SW) as the output signal SW based on the input current.

Methods and apparatuses for selective harmonic current mitigation pulse width modulation (SHCM-PWM) are provided. Low switching frequencies can be utilized for grid connected cascaded H-bridge multilevel rectifiers to meet harmonic requirements within an extended harmonic spectrum. Instead of using voltage references to calculate switching angles for rectifiers as in conventional selective harmonic elimination-PWM (SHE-PWM) and selective harmonic mitigation-PWM (SHM-PWM), current references can be used to compensate for current harmonics and meet current harmonic requirements and total demand distortion (TDD) within the entire harmonic spectrum.

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Rolla, MO, United States of America

Amirhossein Moeini