CAJ | 학술논문

在高功率超导磁储能装置(superconducting magnetic energy storage，SMES)中，电压源型功率调节系统首先利用多相斩波器将超导磁体电流转化成稳定的直流电压，再利用后级电压源型变流器(voltage source converter，VSC)与交流
재고공솔초도자저능장치(superconducting magnetic energy storage，SMES)중，전압원형공솔조절계통수선이용다상참파기장초도자체전류전화성은정적직류전압，재이용후급전압원형변류기(voltage source converter，VSC)여교류
In the high power superconducting magnetic energy storage (SMES) device, the voltage source converter (VSC) based power conditioning system (PCS) first converts the current of the superconducting magnetic to a stable DC voltage with the help of a multiphase chopper, and then utilizes a VSC to communicate power with the AC system. However, in the situation when the power communication between SMES and the grid changes too fast, a multiphase chopper with traditional current-self-shared PI controller has some problems such as the DC voltage deviation and transient current unbalance. The DC voltage deviation will further exert adverse effects on the control accuracy and speed of the succeeding VSC. To overcome these problems, this paper deduces the switching-function model of the multiphase chopper, and proposes a vector-switching-based control method using the deduced model. This method utilizes the hysteresis to switch the control vector to realize the DC voltage control, at the same time utilizes the redundant switch combinations of a control vector to realize the current sharing. Simulation shows that the proposed method can eliminate the DC voltage deviation when the power communication suddenly changing, and thus, provides a favorable condition for the fast and accurate control of the VSC. Besides, the proposed method can also realize current-sharing of the multiphase chopper in most of the situations, and therefore ensure the long-term operation of the system reliably.