Time filter

Source Type

Ai H.,Beijing Jiaotong University | Wu J.,Beijing Jiaotong University | Hao L.,Beijing Jiaotong University | Feng B.,Beijing Energy Investment Ltd. Company | And 2 more authors.
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2015

In terms of the imbalance problems of the state of charge of batteries in independent battery powered hybrid cascade energy storage system, this paper proposes a new control strategy, the difference charge or discharge, which based on Selective Harmonic Elimination PWM. When the state of charge of batteries is imbalanced, carry on difference charge or discharge to adjust the state of charge of batteries convergence. If balanced, transfer to the synchronous charge or discharge by using phase shift SPWM. As a result, it improves the whole hybrid cascade storage system availability and capacity and prolongs the batteries' service life even that of the whole system. This paper derives the principle of difference charge or discharge control method and puts forward the switching condition. Its reasonable and feasibility are verified by an example of hybrid cascade energy storage system, from theoretical analyses in conjunction with model investigations established in PSCAD/EMTDC. ©, 2015, The editorial office of Transaction of China Electrotechnical Society. All right reserved. Source

Tian M.,Beijing Jiaotong University | Wu J.,Beijing Jiaotong University | Hao L.,Beijing Jiaotong University | Xiong F.,Beijing Jiaotong University | And 2 more authors.
Dianwang Jishu/Power System Technology | Year: 2015

A kind of multi-port DC/DC converters (MPC) energy storage system accessible to multiple battery packs was presented. Its topology and working principle were analyzed briefly, and the control methods and starting mode selection for each port were studied. As a single DC/DC port boot incorporation will have a huge transient disturbance on whole storage system, and directly threaten stable operation of energy storage system, this paper focuses on research of soft starting mode of MPC storage system. By deriving equivalent circuit and formula, the optimal selection of relaxation port soft starting resistance and the setting of power port soft starting initial duty ratio are analyzed in detail, and then a three port DC/DC experimental prototype is developed with input voltage 100~140 V, output voltage 240 V, rated power 3.6 kW. Through experiment, effectiveness of the proposed soft starting mode and associated control strategy are verified, therefore providing a stable and flexible switching solution for each port of the multiple battery packs MPC energy storage system. ©, 2015, Power System Technology Press. All right reserved. Source

Discover hidden collaborations