Shanghai Jiaotong University

Hangzhou Dianzi University

Lijun Hang

Guojie Li

Anping Tong

Keyou Wang

Xiuchen Jiang

Lin Feng

Bei Han

Lei Shen

Chi Shao

Yuanbin He

Jingzhou Xu

Shenglun Chen

Pingliang Zeng

The present disclosure discloses a hybrid five-level bidirectional DC/DC converter and a voltage match modulation method thereof. The converter includes a first input filter capacitor Cand a second input filter capacitor C, an output filter capacitor C, a DC voltage source, a primary-side hybrid five-level unit, a primary-side two-level half bridge, a secondary-side single-phase full bridge H, a high-frequency isolation transformer M, a high-frequency inductor L, and a controller. A positive pole of a DC bus of the primary-side hybrid five-level unit is coupled to a positive pole of the corresponding DC voltage source and to a positive pole of the input filter capacitor Crespectively. A negative pole of the DC bus of the primary-side hybrid five-level unit is coupled to a negative pole of the corresponding DC voltage source and to a negative pole of the input filter capacitor Crespectively. A terminal of the primary-side hybrid five-level unit is coupled to a midpoint between the first input filter capacitor Cand the second input filter capacitor Cconnected in series. The primary-side hybrid five-level unit is coupled to a primary side of the high-frequency isolation transformer Mthrough the high-frequency inductor L, and a midpoint of the primary-side two-level half bridge is coupled to another terminal of the primary side of the high-frequency transformer.

Hybrid five-level bidirectional DC/DC converter and voltage match modulation method thereof

A diode clamp mixed three-level dual-active full-bridge converter based on a dual active full-bridge converter, an additional control variable is added by replacing two-level bridge arm on the primary side with a diode clamp three-level bridge arm. A control method based on four variables including duty ratios of 0 voltage level and high voltage level of the primary side, duty ratio of 0 voltage level of the secondary side of the diode clamp mixed three-level dual active full-bridge converter, and phase shift ratio between primary and secondary sides of the diode clamp mixed three-level DAB converter; four-degree-of-freedom globally optimized control is realized by coordinating four variables, RMS value of the current is reduced, and operating efficiency of the converter is improved. Closed-loop control of the DAB globally optimized operation is given, which enables the converter to automatically realize globally optimized operation under different operating conditions.

Diode clamp mixed three-level dual active full-bridge converter and control method thereof

A current sensorless control system and a control method thereof for single stage isolated PFC converters based on DAB. By coordinating three control variables of the DAB converter, that is, the inside phase-shifting ratio of the primary side full-bridge, the inside phase-shifting ratio of the secondary side full-bridge, and the phase-shifting ratio between the primary and the secondary sides, the present invention does not need to design additional current controller for the control of the input current, and may make the input current sinusoidal by directly coordinating the output voltage controller, the input voltage and the current modulation step, thereby reducing system cost and the difficulty of controller design, enhancing the stability of the control system, and improving the dynamic performance.

Current sensorless control method for DAB-based single stage isolated PFC converters

A globally optimal close-loop controlling method for a triple-phase-shift modulated DAB converter, which is based on three control variables of the internal phase shift ratio of the primary side full bridge, of the internal phase shift ratio of the secondary side full bridge, and of the phase shift ratio between the primary and the secondary side, of a DAB (dual active bridge-isolated bidirectional DC/DC dual active bridge-isolated bidirectional DC/DC) converter, enabling the DAB to automatically realize global optimal operation via close-loop controlling means under various conditions, thus raising DAB efficiency. The method of close-loop control with global optimization for the DAB has a good controlling performance.

Globally optimal close-loop controlling method for triple-phase-shift modulated DAB converter

A feedforward voltage series compensator based on complimentary use of wind, solar, and electric power comprising a controller, a rectifier unit, an H bridge inverter, a series transformer, a wind-power DC voltage sensor, a wind-power DC current sensor, an AC voltage transducer, a DC boost unit, a PV DC voltage sensor, a PV DC current sensor, and a grid-connected inverter. The compensator makes use of wind-electric and photovoltaic-electric complimentary interactions to solve the traditional energy issue for series compensator, and as the grid-connected inverter is feedforward, there is extra capacity for the series transformer and the series complimentary inverter unit, and hence it enjoys the feedforward and quick voltage complimentary characteristics of the wind and solar power generation.

Feedforward voltage series compensator based on complementary use of wind power and photovoltaic power

A method for designing cascaded multi-level inverters with minimization of large-scale voltage distortion, based on KKT (Karush-Kuhn-Tucker) conditions and with simplified computation of conduction angles, simplifies the computation process, and is conducive to on-line calculation. Meanwhile, its fundamental voltage is adaptive, minimization of total harmonic is realized for cascaded multi-level inverters at high-voltage, and voltage power quality at grid connected nodes is improved.

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Shanghai, China

Lijun Hang