X. F. JIANG ET AL. 609

Engineering hub mainly consists by three big building

supper reservoir, water power generation system and

lower reservoir, which installing four 300 MW each re-

versible hydraulic pump unit, gross installed capacity is

1200 MW. It is designed to generate peak power, 1.606

billion kW·h, and to consume 2.141 billion kW·h by

pumping each year.

4. The Scheduling Strategy of Pumped

Storage Power Plant

4.1. Considering the Basic Idea of Pumped

Storage Power Plant Grid Dispatching Mod-

el

The basic idea of the scheduling model is: start from the

whole power system and the reality, fully consider of the

technical and economic characteristics of all kinds of

power station in the system[4] (including hydropower

and thermal power, nuclear power and pumped storage

power station, etc.) and relevant operation system con-

straints under the situation that the load, the installed

capacity of power station and hydropower station’s hy-

drological data known. Arrange the working position and

capacity of each power station in system typical day

(week) month after month in load curves; make full use

of hydropower, to reduce the system conventional ther-

mal power unit boot capacity. Make work position and

work capacity of pumped storage, thermal power, nuclear

power stations and their start-stop by economical effi-

ciency, to meet operation system load demand on the

best ways.

The goal is to make the entire units operation cost

minimum in the system, and also to make the conven-

tional thermal power unit capacity and the electricity

generation least, to achieve the purpose of section coal.

Operation simulation calculation process and proce-

dure roughly as follows:

1) Look for the work position of hydropower, accord-

ing to the adjustable output and expected power in hy-

drological years,

2) Get the work position pumped storage power plant,

3) Calculate the generation process, storage capacity,

electricity and operation cost, etc., according to the work

position.

4.2. The Mathematics Model of the Pumped

Storage Power Station’s Scheduling

Planning

4.2.1. The Objective Function

The objective function of operation simulation of pumped

storage power plant is the minimized operation cost in

research period

1

min ()

T

tt t

t

CFR

D (1)

C: the total cost of operation every week in the system,

ten thousand;

t

is the fixed operation cost at t period in the system;

t is the fuel cost at t period in the system; t is the

variable cost at t period in the system, including the start-

stop losses and the operation cost of the hydropower and

pumped-storage units, ten thousand; T is the number of

operation cycle time, this paper take T = 168 h.

R D

Hydropower units with no coal consumption, so fuel

costs can be neglected[5]; the pumped-storage units re-

place other units to generate power in power generation

condition, its power benefit is the operating costs of the

replaced units, when the pumped-storage unit in pumping

condition, the pumping cost equals the increased supply

of pumping thermal power unit of power operation costs.

So the objective function for the plan is practical calcula-

tion and pumped storage power station in valley of

pumping after thermal power unit system operation cost

and the pumped-storage unit to substitute other unit’s

load the fixed cost saving the minimum sum.

4.2.2. Constra i nt Con d i tion

a) The related constraints of pumped storage

1) Pumped storage capacity constraints

Power generation capacity constraint

,max

0()

gg

Pt P

(2)

Pumping capacity constraint

,max

0()

pu pu

Pt P

(3)

Without other restrictions, to make full use of the unit

capacity, generally think,maxg, equal to the

pumped storage power plant capacity.

P,maxpu

P

2) Power balance constraints

Under the restricted constraints ①, get week pumping

power:

7 168

11

() ()

pu

it

Epu iPt

(4)

The biggest generating capacity constraints on i day:

1

11

0()() (

ii

Eg iEpuiEgi

)

(5)

Eg (0) = 0.

3) Capacity constraints

Set pumped storage power station as a reference for

processing agricultural products on power C, then

max(( ))Es iC (6)

4) Work position constraints

To avoid the position overlap of pumped storage posi-

tion and generation position, it must satisfy the follow:

Copyright © 2013 SciRes. EPE