System Overview
Acrel-2000MG Microgrid Energy Management System is a professional energy management system designed by our company based on the latest requirements of the current power system. It incorporates extensive feedback from power system users and experts, absorbs successful experiences from domestic and international manufacturers, and combines our years of rich experience in power system automation product design. The system adopts an object-oriented, layered, and distributed design philosophy, applying power automation technology, computer technology, network technology, and communication technology.
Acrel-2000MG Microgrid Energy Management System can orderly manage and optimize control of the sources (grid power, distributed photovoltaic, micro wind turbines), network (internal distribution network), loads (fixed and adjustable loads), energy storage systems, and electric vehicle charging loads of enterprise microgrids. It achieves flexible interaction between resources under different objectives, enhances the stable operation of the system under multi-strategy control, promotes renewable energy consumption, rationally flattens peaks and fills valleys, reduces grid construction investment, improves energy utilization efficiency, lowers operating costs, and achieves energy conservation and consumption reduction.
Acrel-2000MG Microgrid Energy Management System communicates directly with devices in the substation layer via Ethernet or RS-485 bus. The system design adheres to international standards IEC 60870-5-103, IEC 60870-5-104, Modbus RTU, Modbus TCP, DLT-645, CDT, MQTT, etc., greatly enhancing security, reliability, and openness.
Acrel-2000MG Microgrid Energy Management System features telemetry, remote signaling, remote control, remote adjustment, remote setting, event alarms, curves, reports, and user management functions. It can monitor the operational status of devices in the power system, achieve rapid alarm response, and prevent serious faults.
Acrel-2000MG Microgrid Energy Management System’s main characteristics include an open system architecture, modular design, strong hardware compatibility, good software portability, and rich application functions. The system has powerful processing capabilities, fast event response, a user-friendly interface, and convenient expansion methods. The system software design follows software engineering design specifications, with reasonable module division and clear interfaces, mainly including human-machine interface, real-time events, event processing, data collection, data monitoring, comprehensive control, graphical configuration, and comprehensive configuration modules.
Acrel-2000MG Microgrid Energy Management System adopts a C/S architecture, supports multiple client access, and can stably run on operating systems such as Win10, Linux (including Ubuntu, Kylin V10 desktop version, and Ningshi Linx).
Application Locations
Acrel-2000MG Microgrid Energy Management System plays a crucial role in various locations to ensure the stability, safety, and efficiency of power supply. The following are some main application locations: parks, communities, islands, charging stations, as well as enterprises such as steel mills, chemical plants, cement factories, data centers, and hospitals.
System Features
The system is divided into three layers: the station control layer, network layer, and substation layer. The devices in the substation layer are relatively independent and only interconnect with the station control layer through the network layer. The station control layer deploys cluster control units responsible for data processing, storage, monitoring, and control of photovoltaic, wind, energy storage, rectification, and charging units within the station. The substation layer consists of relevant devices with measurement and control functions (photovoltaic, wind, energy storage controllers, charging monitoring systems, billing control units, etc.), responsible for data collection and forwarding, and responding to commands from the station control layer. Network devices are responsible for communication between the two layers.
The system can be flexibly configured according to user needs. Each application unit of the system is designed modularly, allowing for grouping and separation.
The system supports international standard communication protocols such as IEC 60870-5-103, IEC 60870-5-104, Modbus RTU, Modbus TCP, DLT-645, CDT, MQTT, etc., allowing products from other manufacturers that support these standards to be easily integrated into the Acrel-2000 MG Microgrid Energy Management System. Other non-standard protocols can be flexibly integrated through custom-developed drivers.
The system can use various communication media such as fiber optics and cables, with flexible networking methods. It can form a fiber self-healing ring Ethernet, a fiber star network, or a bus network.
The system has excellent openness. It combines large commercial databases with real-time databases, achieving seamless connection and unified management of historical and real-time database access.
The system database is defined based on the characteristics of substation automation, establishing a template library according to substations, devices, etc. Engineering and operation maintenance personnel can easily derive actual objects from templates, greatly simplifying and facilitating engineering production and maintenance.
The system graphical configuration module fully absorbs the advantages of foreign graphical configuration software, with powerful functions and strong versatility. Since the design considers general graphical configuration software, it can be used not only for substation monitoring systems but also for other types of monitoring systems.
The system provides powerful and flexible report generation tools. What you see is what you get, and it can be automatically generated. It can meet the needs of various users and provide typical report templates for user convenience.
The main management objects of the microgrid energy management system
Distributed Power Sources
The distributed power sources in the microgrid include fuel cells, micro gas turbines, diesel generators, combined heat and power systems, wind power, and photovoltaics. Among them, the combined heat and power system provides thermal energy while generating electricity through fuel cells, micro gas turbines, or other engines, achieving energy utilization rates above 90%, and has good application prospects in microgrids. Different types of power sources convert electrical energy of different frequencies into the same frequency AC or DC power smoothly through power electronic devices such as rectifiers and inverters. By controlling the inverter, the output of the distributed power source can be regulated to specified voltage and frequency or active and reactive power (i.e., control). These inverter-based control methods support the overall control strategy of the microgrid system. Distributed power sources are classified into non-dispatchable units and dispatchable units. Wind and solar power generation mainly depends on the natural environment, exhibiting randomness and volatility, and belongs to non-dispatchable units, which have a certain predictability but still have significant prediction errors. In contrast, fuel units such as micro gas turbines, fuel cells, and diesel engines belong to dispatchable units. The microgrid energy management system needs to predict the output of wind and solar power and formulate dispatch plans for dispatchable units based on predicted output, fuel unit fuel consumption, thermal demand, etc.
Energy Storage Systems
Energy storage systems are widely used in microgrids. The energy storage technologies suitable for microgrids mainly include batteries, flywheels, and supercapacitors. Batteries have characteristics such as large energy capacity, high energy density, and short cycle life, playing a role in peak shaving and energy scheduling when connected to the grid, and often serving as the central storage unit in island mode to maintain the stability of microgrid frequency and voltage. Flywheels have high energy density, high power output, and unlimited charge/discharge cycles, commonly used to smooth out instantaneous power fluctuations in microgrids. Supercapacitors have high power density, long cycle life, and low energy density, but they are relatively more expensive compared to the other two energy storage technologies. Due to their low inertia, energy storage systems can smooth out power fluctuations from renewable energy and loads in microgrids, maintaining real-time power balance in the system, while also providing instantaneous power support during transitions between grid-connected and island modes to maintain system stability. Energy storage systems are generally connected to microgrids through inverters, using droop control and PQ control, and accept commands from the microgrid energy management system to determine operational modes and power generation. The management objectives of energy storage systems depend on the operational mode of the microgrid. In grid-connected mode, the main goal is to ensure stable output from distributed power sources, and when capacity is sufficient, it can assist in peak shaving and energy scheduling; in island mode, the energy storage system primarily maintains system stability and reduces power fluctuations for end users.
Load Systems
To ensure that the microgrid can still operate in emergencies, the loads of the microgrid are generally managed hierarchically, mainly divided into critical loads and controllable loads. Critical loads are those that require prioritized protection of power supply; controllable loads can be appropriately curtailed in emergencies and can also optimize load usage and save energy through demand-side management or demand-side response under normal circumstances. For example, a building can achieve energy savings by adjusting the heating, ventilation, and air conditioning (HVAC) system or lighting system without affecting user satisfaction. Load-side management in microgrids is an important part of energy management. With the popularity of electric vehicles, charging electric vehicles (PEV) and plug-in hybrid electric vehicles (PHEV) have been widely used in microgrids. PHEV and PEV can charge from the grid anytime and anywhere, and can also discharge power back to the grid through vehicle-to-grid (V2G) technology, having dual identities as controllable loads and power sources. The large-scale integration of such loads will increase the complexity of the microgrid energy management system.
In summary, the energy management of microgrids is an important research area in microgrid technology. With the continuous development and expansion of microgrids, energy management will face a series of issues that need to be addressed, including control structures, optimization algorithms, and communication designs. This article summarizes the current research status of microgrid energy management both domestically and internationally, providing a comprehensive introduction to the management objects, basic functions, design framework, and control structures of microgrid energy management systems, as well as the composition and main functions of their software and hardware. Additionally, it presents the basic models and optimization algorithms for microgrid energy management in theoretical research, summarizes the existing problems and challenges in current research work, and points out directions for further research.