|
|
Constant Capacitor Voltage Control Strategy for Z-Source/ Quasi-Z-Source Inverter in Grid-Connected Photovoltaic Systems |
Li Yuan1, Peng Fangzheng2 |
1. Sichuan University Chengdu 610065 China 2. Michigan State University East Lansing 48824 US |
|
|
Abstract With unique impedance network and shoot-through, Z-source inverter (ZSI)/ quasi-Z-source inverter (qZSI) can realize buck/boost and DC-AC conversion in a single stage system. It is suitable for grid-connected photovoltaic (PV) power generation systems, where the input voltage varies in a wide range. By taking voltage-source qZSI with continuous input current as an example, this paper provides voltage boost theory and circuit operation principle of the ZSI/qZSI. Based on the demanded mutual limitation of the shoot-through duty ratio and modulation index for ZSI/qZSI, the capacitor voltage range of ZSI/qZSI is investigated and a constant capacitor voltage control strategy is presented for ZSI/qZSI based grid-connected PV systems. The proposed control strategy decouples maximum power point tracking (MPPT) (for power flow control) and grid current control (for power quality); simplifies the controller design; realizes closed-loop control for the ZSI/qZSI grid-connected PV system as well as MPPT. Moreover, the proposed control strategy ensures minimum voltage stress on switching devices when with the same input and output voltage level.
|
Received: 09 January 2011
Published: 07 March 2014
|
|
|
|
|
[1] Huang Y, Shen M S, Peng F Z. Z-Source inverter for residential photovoltaic systems[J]. IEEE Transactions on Power Electronics, 2006, 21(6): 1776- 1782. [2] 杨水涛, 丁新平, 张帆. Z-源逆变器在光伏发电系统中的应用[J]. 中国电机工程学报, 2008, 28(17): 112-118. [3] Li Y, Anderson J, Peng F Z, et al. Quasi-Z-source inverter for photovoltaic power generation systems[C]. IEEE Applied Power Electronics Conference, 2009: 918- 924. [4] Li Y, Peng F Z, Cintron Rivera J, et al. Controller design for quasi-Z-source inverter in photovoltaic systems[C]. IEEE Energy Conversion Congress & Expo., 2010: 3187-3194. [5] Peng F Z. Z-source inverter[J]. IEEE Transactions on Industry Applications, 2003, 39(2): 504-510. [6] Peng F Z, Shen M, Qian Z. Maximum boost control of the Z-source inverter[J]. IEEE Transactions on Power Electronics, 2005, 20(4): 833-838. [7] Shen M S, Wang J, Joseph A, et al. Constant boost control of the Z-source inverter to minimize current ripple and voltage stress[J]. IEEE Transactions on Industry Applications, 2006, 42(3): 770-778. [8] Ding X P, Qian Z, Yang S T, et al. A direct peak DC-link boost voltage control strategy in Z-source inverter[C]. IEEE Applied Power Electronics Conference and Exposition, 2007: 648-653. [9] Ding X P, Qian Z, Yang S T, et al. A PID control strategy for DC-link Boost voltage in Z-Source inverter[C]. IEEE Applied Power Electronics Conference and Exposition, 2007: 1145-1148. [10] Yang S T, Ding X P, Zhang F, et al. Unified control technique for Z-source inverter[C]. IEEE Power Electronics Specialists Conf., 2008: 3236-3242. [11] Anderson J, Peng F Z. Four quasi-Z-source inverters[C]. IEEE Power Electronics Specialists Conference, 2008: 2743-2749. [12] Kjaer S B, Pedersen J K, Blaabjerg F. A review of single-phase grid-connected inverters for photovoltaic modules[J]. IEEE Transactions on Industry Applic- ations, 2005, 41(5): 1292-1306. [13] IEEE Standard for Interconnecting Distributed Resources with Electric Power Systems[S]. IEEE Std—1547, 2003. |
|
|
|