Primary Frequency Control Contribution From Smart Loads Using Reactive Compensation

Abstract

Frequency-dependent loads inherently contribute to primary frequency response. This paper describes additional contribution to primary frequency control based on voltagedependent noncritical (NC) loads that can tolerate a wide variation of supply voltage. By using a series of reactive compensators to decouple the NC load from the mains to form a smart load (SL), the voltage, and hence the active power of the NC load, can be controlled to regulate the mains frequency. The scope of this paper focuses primarily on reactive compensators for which only the magnitude of the injected voltage could be controlled while maintaining the quadrature relationship between the current and voltage. New control guidelines are suggested. The effectiveness of the SLs in improving mains frequency regulation without considering frequency-dependent loads and with little relaxation in mains voltage tolerance is demonstrated in a case study on the IEEE 37 bus test distribution network. Sensitivity analysis is included to show the effectiveness and limitations of SLs for varying load power factors, proportion of SLs, and system strengths.Index Terms-Demand response (DR), demand-side management (DSM), electric spring (ES), primary frequency control, reactive compensator, smart load (SL), voltage control.

Smart Loads for Improving the Fault-Ride-Through Capability of Fixed-Speed Wind Generators in Microgrids

“…Hence, more diverse control options and wider operating range are achievable using ES technology. Since its first report, the ES-enabled smart load technology has been demonstrated to possess a series of favorable features, including power balancing [20], power quality improvement [21], and primary frequency control [22].…”

Use of Smart Loads for Power Quality Improvement

“…It was implemented to reduce 71 the power imbalance in a three-phase four-wire power system 72 and also retains the useful function of ES-1 for voltage 73 stabilization. Since the first paper in ES appeared in 2012 [12], 74 active research on this topic has been conducted in the 75 U.K. [15]- [17], Denmark [18], [19], China [20], Singapore 76 [21], [22], Middle East [23], [24], and India [25], [26].…”

“…It was implemented to reduce 71 the power imbalance in a three-phase four-wire power system 72 and also retains the useful function of ES-1 for voltage 73 stabilization. Since the first paper in ES appeared in 2012 [12], 74 active research on this topic has been conducted in the 75 U.K. [15]- [17] Fig. 2(a) and (b), pure capacitive and inductive modes can be 131 accomplished by setting V es to be perpendicular to V nc (V es 132 is 90°leading V nc for inductive mode and 90°lagging V nc 133 for capacitive mode).…”

“…The above assumption of noncritical load as pure resistive 247 load is not a necessary condition in implementing an ES 248 system [15]- [17]. Here, (1) is rewritten as (8) to evaluate the 249 impact of noncritical loads on the operation of the ES…”

Rapid frequency response from smart loads in great britain power system

“…In [20] distributed voltage control capability of smart load has been compared against STATCOM while [21] demonstrate the effectiveness of smart loads in primary frequency control considering only a segment of the MV/LV network.…”