Dead-Beat Control Cooperating with State Observer for Single-Phase Electric Springs

Abstract

Aiming at improving the performance of the existing for single-phase electric springs (ESs), such as the fastness of the voltage stabilization and the mitigation of the voltage harmonics across the critical loads (CLs), the dead-beat control cooperating with state observer is proposed in this paper. First, the δ control is reviewed, outlining its features of regulation of the CL voltage while keeping the ES operation stable. After describing the operation of an ES in the continuous-time domain by the state-space technique, its discrete-time model is formulated using the zero-order-hold (ZOH) algorithm. Then, the control system for an ES is designed around the dead-beat control cooperating with a state observer and implementing the two typical compensation functions achievable with the δ control, namely the pure reactive power compensation and the power factor correction. Results obtained by simulation demonstrate that the control system is able to both properly drive an ES and to implement the two functions. The results also show that the proposed control system has the advantage of eliminating harmonic components in CL voltage when grid voltage distorts.

Seamless mode‐switching control for electric spring with capacitor DC bank

“…However, it did not present the reference voltage phase angle the ES should use when the voltage fluctuates. In [16], a dead‐beat control for reducing harmonics was proposed. However, this method needs to know the generator outlet side voltage, which is hard to acquire.…”