Dynamic Modeling of Electric Springs

Abstract

Abstract-The use of 'Electric Springs' is a novel way of distributed voltage control while simultaneously achieving effective demand-side management through modulation of noncritical loads in response to the fluctuations in intermittent renewable energy sources (e.g. wind). The proof-of-concept has been successfully demonstrated on a simple 10 kVA test system hardware. However, to show the effectiveness of such electric springs when installed in large numbers across the power system, there is a need to develop simple and yet accurate simulation models for these electric springs which can be incorporated in large-scale power system simulation studies. This paper describes the dynamic simulation approach for electric springs which is appropriate for voltage and frequency control studies at the power system level. The proposed model is validated by comparing the simulation results against the experimental results. Close similarity between the simulation and experimental results gave us the confidence to use this electric spring model for investigating the effectiveness of their collective operation when distributed in large number across a power system. Effectiveness of an electric spring under unity and non-unity load power factors and different proportions of critical and non-critical loads is also demonstrated.Index Terms-Demand side management, reactive power control, electric springs

Distributed Voltage Control with Electric Springs: Comparison with STATCOM

“…Modeling and control of ES is discussed in [13]. The magnitude of the controllable voltage representing the ES is controlled using a PI controller to minimize the difference between the actual and reference values of the voltage across the critical load.…”

Enhancement of Load Voltage Regulation Using Electric Spring

“…Fig 6. The injected voltage by the ES is represented as V es . R f , L f and C f are the resistance, inductance and capacitance of the output filter at the inverter terminal [6].…”

Peak Shaving in Power system using VSC based Electric spring

“…This can be achieved by increasing modulation index. [5] To supply constant power supply from intermittent source to the load, the modulation index is decreased. This concept is illustrated in Fig.7.…”