Abstract
Adopting the battery energy storage system is an effective way to compensate the continuously growing fluctuating power generated by renewable sources. The power conversion system is considered as one of the core equipment used for interfacing battery packs to the grid in a battery energy storage system. This paper aims to apply an improved active damping control to a grid-tied power conversion system with LCL filter to attenuate its inherent resonance characteristics. The anti-interference ability is enhanced by estimating the second-order derivation of grid-injected current based on a modified disturbance observer. Meanwhile, the negative effects of parameter mismatch are equivalent to unmeasurable disturbances, which are possible to be compensated by subtracting the estimated values from the modulated voltage references. Moreover, the design method and robustness issue of the disturbance observer are discussed in detail. The presented control algorithm is implemented based on Simulink and dSpace. Detailed simulation results are provided, which can verify the feasibility and correctness of control strategy. Furthermore, an experimental prototype rated at 2.3 kW/110 V is constructed. The experimental results confirm that the presented control method is effective to be applied in the power conversion system (PCS).
Highlights
The everlasting development of renewable generation systems brings about a potential challenge to the stability of grid, since the balance between electrical energy providers and consumers recently becomes much harder to be maintained [1,2]
Power conversion system (PCS), which can be classified to a dedicated kind of gridtied converter, is the intermediate power electronics equipment between battery packs and grid
Damping method and disturbance rejection are both fundamental issues in a grid-tied PCS equipped with an LCL filter
Summary
The everlasting development of renewable generation systems brings about a potential challenge to the stability of grid, since the balance between electrical energy providers and consumers recently becomes much harder to be maintained [1,2]. The authors in [17] employed a selective frequency scheme which localized the influence scope of AD loop only near the resonance frequency; the inverter’s feature in other frequency range stayed the same to provide better steady and dynamic performances For another aspect, disturbances and uncertainties are inevitable in most practical industrial applications. 2. Principle of Active Damping Control and Disturbance Observer Figure 1 briefly illustrates the block diagram and control principle of PCS on basis of a widely-used two-level voltage source converter. It is necessary to adopt either active or passive damping methods to attenuate the resonance peak of LCL filter for purpose of guaranteeing the stability of PCS. According to the modified block diagram, it can be found that adding Gad(s) in the control loop has the same effect as connecting a virtual resistor Rc in parallel with filter capacitor which can be described by Figure 4. Stability analysis and design of Matrix M will be discussed in detail
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
