Impact of Strategic Behaviors of the Electricity Consumers on Power System Reliability

Abstract

Over the past few decades, electricity markets have created competitive environments for the participation of different players. Electricity consumers (as end users in power systems) can behave strategically based on their purposes in the markets. Their behaviors induce more uncertainty into the power grid, due to their dynamic load demands. Hence, a power system operator faces more difficulties in maintaining an acceptable level of reliability and security in the system. On the other hand, the strategic behaviors of electricity consumers can be as a double-edged sword in the power grid. There is a group of consumers who are flexible and so can be interrupted at critical time periods and pursue their economic targets in the electricity markets. However, the second group is concerned with electricity demand being provided to them with the desired reliability level. Hence, the decisions of this group of electrical consumers are in conflict with their corresponding demand response programs. According to the above statement, this chapter aims at investigating the impact of strategic behavior of the electrical consumers on power system reliability. In this way, different agents of electricity markets are defined in this chapter which their behavior can impact the market-clearing problem. Energy and reserve are assumed as electricity commodities in this chapter. Thus, a two-stage, day-ahead and real-time, stochastic unit commitment problem is solved to clear energy and reserve simultaneously considering the uncertainty of wind power generations and conventional generation units which impacts the reliability of sustainable power systems.

Appendix 1: Nomenclature

Indices and Numbers

n	Index of system buses, from 1 to N B.
i	Index of conventional generating units, from 1 to N G.
j	Index of loads, from 1 to N L.
t	Index of time periods, from 1 to N T.
m	Index of energy blocks offered by conventional generating units, from 1 to N Oit.
ω	Index of wind power, electrical load, and power grid scenarios, from 1 to Ω.

Continuous Variables

${C}_{it}^{\mathrm{SU}}\vphantom{\frac{1^{1^{1}}}{1_{1_{1}}}}$	Scheduled start-up cost ($).
P S it	Power output of units in the DAM (MW).
${p}_{itm}^G \vphantom{\frac{1^{1^{1}}}{1_{1_{1}}}}$	Power output from the m-th block of energy offered by the unit in DAM (MW).
L S jt	Power consumed of load in DAM (MW).
R U it	Up-spinning reserve in DAM (MW).
R D it	Down-spinning reserve in DAM (MW).
R NS it	Non-spinning reserve in DAM (MW).
R U jt	Up-spinning reserve from demand side in DAM (MW).
R D jt	Down-spinning reserve from demand side in DAM (MW).
${P}_t^{S,\mathrm{WP}}\vphantom{\frac{1^{1^{1}}}{1_{1_{1}}}}$	Wind power in DAM (MW).
C A itω	Start-up cost due to change in commitment status of units in DAM and RTM ($).
P G itω	Power output of unit in RTM (MW).
L C jtω	Electrical consumed in RTM (MW).
r U itω	Up-spinning reserve in RTM (MW).
r D itω	Down-spinning reserve in RTM (MW).
r NS itω	Non-spinning reserve in RTM (MW).
r U jtω	Up-spinning reserve from demand side in RTM (MW).
r U jtω	Down-spinning reserve from demand side in RTM (MW).
${r}_{itm\omega}^G\vphantom{\frac{1^{1^{1}}}{1_{1_{1}}}}$	Reserve deployed from the m-th block of energy offered in RTM (MW).
${L}_{jt\omega}^{\mathrm{shed}}\vphantom{\frac{1^{1^{1}}}{1_{1_{1}}}}$	Load shedding (MW).
S tω	Wind power generation spillage (MW).
f tω( n,  r)	Power flow through line (n, r) (MW).
P loss tω( n,  r)	Power loss in line (n, r) (MW).
δ tωn	Voltage angle at node.

Binary Variables

u it	Commitment status of units in DAM.
v itω	Commitment status of units in RTM.

Random Variables

P WP tω

Wind power generation in RTM (MW).

Constants

d t	Duration of time period (h).
${\lambda}_{it}^{\mathrm{SU}}\vphantom{\frac{1^{1^{1}}}{1_{1_{1}}}}$	Start-up offer cost of unit ($).
${\lambda}_{itm}^G\vphantom{\frac{1^{1^{1}}}{1_{1_{1}}}}$	Marginal cost of the m-th block of energy offered ($/MWh).
${\lambda}_{jt}^L\vphantom{\frac{1^{1^{1}}}{1_{1_{1}}}}$	Utility of electrical load ($/MWh).
λ WP t	Marginal cost of the energy offer submitted by the wind producer ($/MWh).
VOLLjt	Value of loss load for load ($/MWh).
V S t	Wind spillage cost ($/MWh).
π ω	Probability of scenarios.
${\overline{P}}_{\mathrm{i}}\vphantom{\frac{1^{1^{1}}}{1_{1_{1}}}}$	Maximum capacity of units (MW).
${\underline{P}}_i \vphantom{\frac{1^{1^{1}}}{1_{1_{1}}}}$	Minimum power output of generation units (MW).
B ( n,  r)	Absolute value of the imaginary part of the admittance of line (n, r) (p.u.).
${\overline{f}}_{\left(n,r\right)}\vphantom{\frac{1^{1^{1}}}{1_{1_{1}}}}$	Maximum capacity of line (n, r) (MW).