Delta Electronics, Inc.

Delta Electronics (Shanghai) Co., Ltd

North Carolina State University

Chi Zhang

Peter Mantovanelli Barbosa

Ruxi Wang

Zhiyu Shen

Jinfa Zhang

Hao Sun

Minli Jia

Yungtaek Jang

Sheng-Hua Li

Tomas Sadilek

Misha Kumar

Srdjan Lukic

Xinyu Liang

Boyi Zhang

Anup Anurag

Boxue Hu

Srdjan Srdic

Jui-Chien Hung

Yang Jiao

Satyaki Mukherjee

A hybrid circuit breaker and a pre-charge control method are provided. The hybrid circuit breaker includes an outer branch, a first branch, a first mechanical switch module, a second branch, an electronic switch and a current commutation circuit. The first branch is connected with the outer branch in series. The first mechanical switch module is located on the first branch. The second branch is connected with the first branch in parallel. The electronic switch is located on the second branch. The current commutation circuit includes a voltage source module and an inductor. The voltage source module is located on the second branch. The inductor is located on one of the first branch or the second branch.

Hybrid circuit breaker and pre-charge control method

The present disclosure provides a printed circuit board (PCB) based planar winding structure for a main power transformer and/or an auxiliary power need. The PCB-based planar winding structure can confine electric field through magnetic core potential control and thus create partial discharge (PD) free design for medium voltage (MV) applications. Meanwhile, the winding structure can be formed in the PCB manufacturing process to create a more modular and reliable structure, thereby enhancing manufacturability. Techniques, such as termination treatment, primary and secondary winding arrangements, etc., can be used to control the electrical stress in the medium voltage applications.

Planar winding structure for power transformer

The present disclosure provides a high voltage device built from modular low voltage cells. Each low voltage cell includes a plurality of low voltage semiconductor devices and one or more low voltage passive components. Each cell can be a current-bidirectional two-quadrant switch or a four-quadrant switch. All the cells may be identical and controlled with a delay time in between. Therefore, the total on and off time of the high voltage device can be controlled to reduce the output equivalent dv/dt. The cell's voltage balancing can be achieved through a control algorithm disclosed herein.

High voltage device built from modular low voltage devices and operation methods thereof

The present disclosure provides a three-level rectification DC/DC converter including primary and secondary circuits and a resonant tank circuit. A voltage between two primary terminals is a first voltage. The secondary circuit includes a flying capacitor, a switch bridge arm, and a capacitor bridge arm. The switch bridge arm includes four switches serially connected. Two terminals of the flying capacitor are respectively connected between the first and second switches and connected between the third and fourth switches. Two secondary terminals are respectively connected between the second and third switches and connected between two output capacitors of the capacitor bridge arm. In two consecutive periods of the first voltage, the first and second switches are in an on state for a preset time length after two falling edges respectively, and the third and fourth switches are in the on state for the preset time length after two rising edges respectively.

Three-level rectification DC/DC converter

The present disclosure provides a three-level rectification DC/DC converter including primary and secondary circuits and a resonant tank circuit. A voltage between two primary terminals is a first voltage. The secondary circuit includes two clamping switches, a switch bridge arm, and a capacitor bridge arm. The switch bridge arm includes four switches serially connected. The two clamping switches are connected in series between a node between the first and second switches and a node between the third and fourth switches. Two secondary terminals are respectively connected between the second and third switches and connected between two output capacitors of the capacitor bridge arm. A node between the two clamping switches is connected between the two output capacitors. The second and third switches are at least in an on state for a preset time length after falling and rising edges in a period of the first voltage respectively.

A novel phase-shift based modulation strategy is disclosed that enables a DC-DC converter to operate with zero voltage-switching (ZVS) across wide voltage and power range. The converter operates at a fixed fundamental frequency, with the output current controlled based on an amount of phase shift of the fundamental component at the output of an inverter portion of the converter. To achieve soft switching a rectifier portion of the converter is controlled to phase shift the fundamental component of the rectifier voltage observed at a rectifier reference terminal. More specifically, by requiring a phase shift of the voltage at the rectifier terminal relative to the output voltage of the inverter, the inverter current is such that ZVS is achieved. A converter and method are provided to implement DC-DC conversion with soft switching.

Soft-switched resonant DC-DC converter with wide gain range

The present disclosure provides a three-phase AC/DC converter aiming for low input current harmonic. The converter includes an input stage for receiving a three-phase AC input voltage, an output stage for at least one load, and one or more switching conversion stages, each stage including a plurality of half bridge modules. The switches in each module operate with a substantially fixed 50% duty cycle and are connected in a specific pattern to couple a DC-link and a neutral node of the input voltage. The AC/DC converter further includes one or more controllers adapted to vary the switching frequency of the switches in the switching conversion stages based on at least one of load voltage, load current, input voltage, and DC-link voltage. The converter can also include one or more decoupling stages, such as, inductive components adapted to decouple the output stage from the switching conversion stages.

Multi-phase AC/DC converter

An efficient control method for an isolated multilevel DC/DC resonant converter achieves a wide output voltage range with a narrow device switching frequency range, relative to the output voltage range and the device switching frequency range of the prior art. At any given time, a control circuit selects one of three different modulation schemes to operate the primary-side switching devices of the resonant converter based on at least one of output voltage, output current, input signal, and one or more external control signals. Together with a selected device switching frequency, the three modulation schemes generate different voltage waveforms to a primary-side transformer, which are coupled to the secondary-side to provide different output voltages.

Isolated DC/DC converters for wide output voltage range and control methods thereof

The present disclosure provides a series resonant converter and its corresponding control method. In one aspect, the series resonant converter includes m (m=1,2,3, . . . ) sets of primary side stages in parallel, wherein each primary side stage is identical and includes n (n=2,3, . . . ) stacked element circuits, where the primary side stages receive an input voltage; n&#xd7;m resonant networks coupled to the primary side stages; n&#xd7;m transformers having n&#xd7;m primary side windings and n&#xd7;m secondary side windings, where the primary side windings are coupled to the n&#xd7;m resonant networks; p (p=1,2,3, . . . ) sets of secondary side stages in parallel, wherein each secondary side stage is identical and includes q (q=n&#xd7;m/p) stacked element circuits, where the secondary side stages are coupled to n&#xd7;m secondary side windings; and a control block controlling the primary side switches according to the output voltage, input voltage and input capacitor voltages.

DC-dC resonant converter and control method thereof

The present disclosure provides a three-level rectification DC/DC converter including primary and secondary circuits and a resonant tank circuit. A voltage between two primary terminals is a first voltage. The secondary circuit includes a switch bridge arm and a capacitor bridge arm. The switch bridge arm includes four switches serially connected. A node between the first and second switches is connected to the first secondary terminal, a node between the third and fourth switches is connected to the second secondary terminal, and a node between the second and third switches is connected between two capacitors of the capacitor bridge arm. In two consecutive periods of the first voltage, the first and fourth switches are in an on state for a preset time length after two falling edges respectively, and the second and third switches are in the on state for the preset time length after two rising edges respectively.

Three-level rectification dc/dc converter

The present disclosure provides a series resonant converter and its corresponding control method. In one aspect, the series resonant converter includes m (m=1, 2, 3, . . . ) sets of primary side stages in parallel, wherein each primary side stage is identical and includes n (n=2, 3, . . . ) stacked element circuits, where the primary side stages receive an input voltage; n&#xd7;m resonant networks coupled to the primary side stages; n&#xd7;m transformers having n&#xd7;m primary side windings and n&#xd7;m secondary side windings, where the primary side windings are coupled to the n&#xd7;m resonant networks; p (p=1, 2, 3, . . . ) sets of secondary side stages in parallel, wherein each secondary side stage is identical and includes q (q=n&#xd7;m/p) stacked element circuits, where the secondary side stages are coupled to n&#xd7;m secondary side windings; and a control block controlling the primary side switches according to the output voltage, input voltage and input capacitor voltages.

DC-DC resonant converter and control method thereof

Certain embodiments involve a modular medium voltage fast charger. The modular medium voltage fast charger can include: (1) a predictive power factor correction ('PFC') controller (or predictive controller) for series-interleaved multi-cell three-level boost ('SIMCB') converters, (2) an active neutral point clamped (&#x201c;NPC&#x201d;) dual active bridge (&#x201c;DAB&#x201d;) modulation scheme to achieve soft switching, (3) an auxiliary capacitor to reduce NPC DAB turn-off voltages, (4) a comprehensive and scalable protection circuit, and (5) a high-isolation pulse transformer with a bobbin for reducing coupling capacitance of the pulse transformer.

Modular medium voltage fast chargers

A three-level modulation for an isolated multilevel DC/DC resonant converter offers output voltage regulation capability with fixed switching frequency and achieves high efficiency along with soft-switching of the power switches. The three-level modulation enables current balance in all power devices, therefore, realizes better thermal performance and longer circuit life. An efficient control method that combines the three-level modulation with conventional frequency modulation achieves a wide output voltage range with a narrow switching frequency range. At any given time, a control circuit selects one of two different modulation schemes to operate the primary-side switches of the resonant converter based on an output voltage, or to one or more external control signals. Together with a selected device switching frequency and duty cycles, the two modulation schemes generate different voltage waveforms to a primary-side transformer, which are coupled to the secondary-side to provide different output voltages.

Growing community of inventors

Apex, NC, United States of America

Chi Zhang