Digital Control of Secondary Active Clamp Phase-Shifted Full-Bridge Converters

Che, Yanbo,Ma, Yage,Ge, Shaoyun,Zhu, Dong The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.3

A DSP-based self-adaptive proportional-integral (PI) controller to control a DC-DC converter is proposed in this paper. The full-bridge topology is adopted here to obtain higher power output capability and higher conversion efficiency. The converter adopts the zero-voltage-switching (ZVS) technique to reduce the conduction losses. A parallel secondary active clamp circuit is added to deal with the voltage overshoot and ringing effect on the transformer's secondary side. A self-adaptive PI controller is proposed to replace the traditional PI controller. Moreover, the designed converter adopts the constant-current and constant-voltage (CC-CV) output control strategy. The secondary active clamp mechanism is discussed in detail. The effectiveness of the proposed converter was experimentally verified by an IGBT-based 10kW prototype.

Advanced Droop Control Scheme in Multi-terminal DC Transmission Systems

Yanbo Che,Jinhuan Zhou,Wenxun Li,Jiebei Zhu,Chao Hong 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.3

Droop control schemes have been widely employed in the control strategies for Multi- Terminal Direct Current (MTDC) system for its high reliability. Under the conventional DC voltage-active power droop control, the droop slope applies a proportional relationship between DC voltage error and active power error for power sharing. Due to the existence of DC network impedance and renewable resource fluctuation, there is inevitably a DC voltage deviation from the droop characteristic, which in turn results in inaccurate control of converter’s power. To tackle this issue, a piecewise droop control with DC voltage dead band or active power dead band is implemented into controller design. Besides, an advanced droop control scheme with versatile function is proposed, which enables the converter to regulate DC voltage and AC voltage, control active and reactive power, get participated into frequency control, and feed passive network. The effectiveness of the proposed control method has been verified by simulation results.

Advanced Droop Control Scheme in Multi-terminal DC Transmission Systems

Che, Yanbo,Zhou, Jinhuan,Li, Wenxun,Zhu, Jiebei,Hong, Chao The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.3

Droop control schemes have been widely employed in the control strategies for Multi-Terminal Direct Current (MTDC) system for its high reliability. Under the conventional DC voltage-active power droop control, the droop slope applies a proportional relationship between DC voltage error and active power error for power sharing. Due to the existence of DC network impedance and renewable resource fluctuation, there is inevitably a DC voltage deviation from the droop characteristic, which in turn results in inaccurate control of converter's power. To tackle this issue, a piecewise droop control with DC voltage dead band or active power dead band is implemented into controller design. Besides, an advanced droop control scheme with versatile function is proposed, which enables the converter to regulate DC voltage and AC voltage, control active and reactive power, get participated into frequency control, and feed passive network. The effectiveness of the proposed control method has been verified by simulation results.

Parameter Identification of 3R-C Equivalent Circuit Model Based on Full Life Cycle Database

Che, Yanbo,Jia, Jingjing,Yang, Yuexin,Wang, Shaohui,He, Wei The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.4

The energy density, power density and ohm resistance of battery change significantly as results of battery aging, which lead to decrease in the accuracy of the equivalent model. A parameter identification method of the equivale6nt circuit model with 3 R-C branches based on the test database of battery life cycle is proposed in this paper. This database is built on the basis of experiments such as updating of available capacity, charging and discharging tests at different rates and relaxation characteristics tests. It can realize regular update and calibration of key parameters like SOH, so as to ensure the reliability of parameters identified. Taking SOH, SOC and T as independent variables, lookup table method is adopted to set initial value for the parameter matrix. Meanwhile, in order to ensure the validity of the model, the least square method based on variable forgetting factor is adopted for optimizing to complete the identification of equivalent model parameters. By comparing the simulation data with measured data for charging and discharging experiments of Li-ion battery, the effectiveness of the full life cycle database and the model are verified.

Design of Dual-channel Interleaved Phase-shift Full-bridge Converter

Che, Yanbo,Wang, Dianmeng,Liu, Xiaokun The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.8 No.1

A digital dual-channel interleaved phase-shift full-bridge converter is investigated in this paper, and its topology and principle are analyzed. To realize current sharing and stabilize the output voltage, a controller with current sharing loop and closed voltage loop is employed. In addition, current sharing will increase the output current fluctuation and a new digital interleaved driving technology is proposed to reduce the output current ripple. To verify the analysis, simulation and experiments are carried out, which shows the effectiveness of the proposed control strategies.

Design of Dual-channel Interleaved Phase-shift Full-bridge Converter

Yanbo Che,Dianmeng Wang,Xiaokun Liu 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.4

A digital dual-channel interleaved phase-shift full-bridge converter is investigated in this paper, and its topology and principle are analyzed. To realize current sharing and stabilize the output voltage, a controller with current sharing loop and closed voltage loop is employed. In addition, current sharing will increase the output current fluctuation and a new digital interleaved driving technology is proposed to reduce the output current ripple. To verify the analysis, simulation and experiments are carried out, which shows the effectiveness of the proposed control strategies.

Parameter Identification of 3R-C Equivalent Circuit Model Based on Full Life Cycle Database

Yanbo Che,Jingjing Jia,Yuexin Yang,Shaohui Wang,Wei He 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.4

The energy density, power density and ohm resistance of battery change significantly as results of battery aging, which lead to decrease in the accuracy of the equivalent model. A parameter identification method of the equivale6nt circuit model with 3 R-C branches based on the test database of battery life cycle is proposed in this paper. This database is built on the basis of experiments such as updating of available capacity, charging and discharging tests at different rates and relaxation characteristics tests. It can realize regular update and calibration of key parameters like SOH, so as to ensure the reliability of parameters identified. Taking SOH, SOC and T as independent variables, lookup table method is adopted to set initial value for the parameter matrix. Meanwhile, in order to ensure the validity of the model, the least square method based on variable forgetting factor is adopted for optimizing to complete the identification of equivalent model parameters. By comparing the simulation data with measured data for charging and discharging experiments of Li-ion battery, the effectiveness of the full life cycle database and the model are verified.

Digital Control of Secondary Active Clamp Phase-Shifted Full-Bridge Converters

Yanbo Che,Yage Ma,Shaoyun Ge,Dong Zhu 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.3

A DSP-based self-adaptive proportional-integral (PI) controller to control a DC-DC converter is proposed in this paper. The full-bridge topology is adopted here to obtain higher power output capability and higher conversion efficiency. The converter adopts the zero-voltage-switching (ZVS) technique to reduce the conduction losses. A parallel secondary active clamp circuit is added to deal with the voltage overshoot and ringing effect on the transformer’s secondary side. A self-adaptive PI controller is proposed to replace the traditional PI controller. Moreover, the designed converter adopts the constant-current and constant-voltage (CC-CV) output control strategy. The secondary active clamp mechanism is discussed in detail. The effectiveness of the proposed converter was experimentally verified by an IGBT-based 10kW prototype.

Joint SOC–SOP estimation method for lithium‑ion batteries based on electro‑thermal model and multi‑parameter constraints

Peijun Qin,Yanbo Che,Hongfeng Li,Yibin Cai,Mingda Jiang 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.3

Accurate estimations of the state of charge (SOC) and the state of power (SOP) are required to ensure efficient and reliable utilization of Li-ion batteries. A new joint estimation method of SOC–SOP based on the electro-thermal model and multi-parameter constraints is proposed in this paper. The proposed method introduces temperature as one of the important constraints for SOP and considers the intrinsic relationship between SOC and SOP as well as the influence of voltage, temperature, and SOC on SOP estimation. First, an electro-thermal model is developed to describe the electric and thermal dynamic characteristics of a battery. Second, the battery SOC is accurately estimated by the unscented Kalman filter method. Then the state of power of the battery is predicted under the condition of multi-parameter constraints. Finally, experiments are conducted to verify the effectiveness of the proposed method. Simulation and experimental results show that this method has a high degree of estimation accuracy and is very simple to calculate. Under the DST condition, the maximum relative voltage error within the electro-thermal model is about 5%. The maximum estimation error of the peak discharge power does not exceed 5 W, and the overall average estimation error is about 1.2 W.

Electro-thermal model for lithium-ion battery simulations

Cai, Yibin,Che, Yanbo,Li, Hongfeng,Jiang, Mingda,Qin, Peijun The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.10

With the extensive application of lithium batteries and the continuous improvements in battery management systems and other related technologies, the requirements for fast and accurate modeling of lithium batteries are gradually increasing. Temperature plays a vital role in the dynamics and transmission of electrochemical systems. The thermal effect must be considered in battery models. In this paper, a simulation model of a lithium battery with thermal characteristics is established. This thermal model is coupled with a temperature-dependent 2-RC equivalent circuit model to form an electro-thermal model for lithium-ion batteries. The hybrid pulse power characterization test is used to estimate the equivalent circuit parameters. Finally, under NEDC and DST conditions, battery voltage and temperature estimation results of the electro-thermal model are analyzed to verify the correctness and accuracy of the model. The voltage error is within - 0.16~0.20 V under the NEDC condition. Moreover, under the DST condition, the maximum relative error in the electro-thermal model is within 5%.