IEEE Electrification - December 2020 - 58

construction cost. The capacity price is useful for guiding
the investment to provide a reliable power supply. The
time-of-use price is a kind of real-time marginal electricity price tariff, where users' load demands are charged by
different prices in the off peak and valley. This price can
be used to guide the demand response for users.
The overall topological structure of the park is shown
in Figure 4. The architecture of the microgrid is divided
into a management, coordination, and executive layer. The
management layer, namely, the EMS, is composed of a
cloud management system and a station-side management system. It is the brain of the park and is responsible
for power generation optimal dispatching, load management, energy-storage charging and discharging management, real-time monitoring, and so on.
The coordination layer includes the core switch, central controller, and so on, which can control the system
operation mode and executive layer in real time. In addition, it can interact with the EMS to flexibly exchange the
data of the whole park, which are obtained through meteorological, load, generation, and energy-storage monitoring. Together, the management layer, coordination layer,
monitors, and communication lines make up the communication system of the park.

The executive layer is composed of PV generation
units, energy-storage equipment, and loads. The loads
include electric vehicle (EV) chargers; air conditioners;
experimental platforms; and industrial, commercial, civil
loads. In addition, the executive layer exchanges power
with the grid through a gateway interface cabinet. As can
be seen from the power and communication lines in Figure 4, electrical energy flows only at the executive layer,
which is connected with the coordination layer through
the load controller, PV inverter, and energy-storage converter, which reflects the control of the communication
system over the energy system.

Functions of the Xi'an Industrial Park Microgrid
Figure 5 shows the overall closed-loop process of
TBEA microgrid construction, where there are four
main steps, namely, planning, construction, operation,
and monitoring. In the planning stage, TBEA provides detailed alternatives for the microgrid in the
aspects of power generation, energy storage, and
energy use and establishes the planning model to find
the best options according to the user needs. Then,
the microgrid is put into use after construction has
been completed.

Communication Line

Mobile Terminal

Power Line

EMS Cloud
Mobile Terminal

Grid

Management
Layer

EMS

Coordination
Layer

Central
Control
Unit

Gateway
Interface Cabinet

Core Switch

Executive
Layer

Inverter

Load
Controller

Charger

Storage

Key
Load

Conditioner Testing

Industrial
Load

Civil
Load

Figure 4. The overall topological structure of the Xi'an Industrial Park microgrid. (Source: TBEA Xinjiang Sunoasis Co., Ltd.; used with
permission.)

I E E E E l e c t r i f i cati o n M agaz ine / DECEMBER 2020

IEEE Electrification - December 2020

Table of Contents for the Digital Edition of IEEE Electrification - December 2020