A Demand Response Strategy in High Photovoltaic Penetration Power Systems Considering the Thermal Ramp Rate Limitation

Qi Wang,Zijun Yang,Yi Tang,Chen Li,Quan Yuan

doi:10.1109/access.2019.2952455

Abstract

In high photovoltaic (PV) penetration power systems, thermal units may be unable to cope with the large-scale power imbalance caused by PV reduction due to their ramp rate limitation. This paper formulates a demand response (DR) strategy to compensate for the timing imbalance between load demand and generation while avoiding high scheduling and operational expenses. First, the concept of the equivalent slope (ES) is proposed to measure the ramping speed of the net load curve and accurately quantify the DR aggregate power. Then, a DR strategy is proposed based on the ES and the thermal ramp rate limitation, in which the dynamic factor adjustment (DFA) increases the aggregate power by directly controlling the DR strategies, and the leading adjustment (LA) transfers part of the peak demand to other times when PV generation is abundant. Finally, simulation results verify the validity of the proposed strategy in maintaining the power balance while ensuring the comfort level of consumers.

Highlights

With the rapid growth of photovoltaic (PV) power generation, the concern arises that its intermittency leads to instability and uncertainty of the power system [1]–[3]
DYNAMIC FACTOR ADJUSTMENT METHOD FOR A HIGH EQUIVALENT SLOPE When Sload > Sramp, the equivalent slope of the net load curve exceeds the ramp rate limitation, and the aggregate power provided by the current demand response (DR) strategy cannot maintain the power balance
SIMULATION RESULTS Assume that the power system in Section II has 10,000 households participating in DR

Summary

INTRODUCTION

With the rapid growth of photovoltaic (PV) power generation, the concern arises that its intermittency leads to instability and uncertainty of the power system [1]–[3]. If the rising slope of the net load curve exceeds the thermal power unit ramp rate limitation, it will be challenging to maintain power system balance. This type of problem threatens stable and safe power system operation, and may even cause large-scale black outs in extreme scenarios [9]. When the power imbalance in high PV penetration system is extremely serious, the bi-level strategy cannot support enough DR aggregate power Both the peak demand and the thermal ramp rate limitation should be fully considered to solve the duck curve problem.

PROBLEM DESCRIPTION

DEMAND RESPONSE STRATEGY BASED ON THE

THE IMPACT OF PV PENETRATION ON THE EQUIVALENT SLOPE OF THE NET LOAD CURVE

SIMULATION RESULTS

CONCLUSION