With the rapid development of renewable energy, energy storage technology is gradually attracting widespread attention as a key means to solve the imbalance between energy supply and demand and ensure the stable operation of the power grid. In this field, energy storage EMS (energy management system), as a core component, plays an increasingly important role. This article will give you an in-depth introduction to the components of an energy storage EMS system.
1. Introduction to the functions of the EMS system
The energy management system is an important part of the energy storage system, which provides data management, monitoring, control and optimization for the microgrid dispatching and control center to ensure the stable and efficient operation of the energy storage system. The energy management system provides power and voltage set points for each energy controller inside the energy storage system; Ensure that the thermal load and electrical load requirements of the system are met; Ensure that the system meets the operating protocol with the mainnet system; Minimize energy consumption and system losses; Provide logic and control methods for island operation and reclosing in the case of system failure (plus grid switching unit), etc.
2. EMS networking architectureIn the energy storage system, the EMS communication topology is divided into two layers, the top layer is the centralized monitoring system, and the bottom equipment: energy storage converter, battery management system (BMS), environmental monitoring equipment, fire protection system, air conditioning or access control system, etc. are connected to the monitoring system. The monitoring host completes the network connection, conversion, data acquisition, local data processing, protocol conversion and command exchange between the on-site measurement and control systems, local user screen monitoring operation, control strategy, and web server functions, so as to realize the high-speed collection and transmission of large-capacity real-time data, ensure that the master station system can quickly and accurately obtain all monitoring and monitoring information, and timely feedback the system abnormalities and faults detected by the network to ensure rapid positioning and recovery. 3. EMS function design(1) The real-time monitoring system of power station operation can collect real-time and regular data on all monitored operating parameters and status, process important historical data and store them in the database. Including: the total voltage, current, average temperature, SoC, SOH, charge and discharge current and power limit of each group of batteries in the BMS system, the maximum battery voltage of a single cell, the temperature of a single maximum battery, fault and alarm information, historical charge and discharge power, historical charge and discharge power and other common information. The relevant parameters of PCS include: voltage, current, power, etc. of each branch on the DC side, active power, reactive power, voltage, current, power factor, frequency and temperature, cabinet temperature, operating status, alarm and fault information and other common information on the AC side, as well as daily charge, daily discharge, cumulative charge, cumulative discharge, etc. Information such as voltage, current, active power, reactive power, frequency and other information of each phase of the load.
Figure 7 Rendering of the main page of the EMS system (for reference only).
2) The operation data of the power station is displayed.
According to the user's requirements, the system can customize the relevant data required by the user to the specified interface, view real-time data and historical data, and export reports.
3) Economic operation strategy of power station.
Compared with the economic operation analysis of conventional substation, which mainly calculates the curve of transformer loss with load current under various operation modes, the economic operation analysis of microgrid system replaces the transformer with pcs and inverter for calculation and analysis, analyzes the current energy storage power and load ratio, obtains the best operation strategy, and executes optimization commands.
4) Real-time dispatching and remote dispatching of power stations.
According to the different system requirements of the on-site monitoring layer and the general control center, the field equipment layer of the microgrid power station can freely configure the data to be uploaded to the on-site monitoring layer and the central control center respectively, or it can be processed and screened by the on-site monitoring layer and uploaded to the general control center.
5) Power plant energy management.
The system automatically controls the direction of the power flow according to the current period, current load, current feed-in tariff, and energy storage battery SoC, and determines the charging and discharging period of the microgrid system.
6) Fault alarm.
The system provides the recording and query functions of events at all levels, and uses colors to distinguish and manage the type and importance of events.
7) Reports, real-time curves, energy flow display.
The system provides real-time curve recording, analysis and query functions, freely select the data to be recorded and analyzed, and display real-time data, historical data and historical data statistics in curves and bar charts, with statistical data intervals of 5 minutes, 15 minutes, 1 hour and 1 day.
The system can customize various reports, analysis charts, and export Office or PDF files according to user requirements.
8) Data analysis.
Common data analysis toolkits include energy flow diagrams, cost accounting, energy saving analysis, production energy efficiency analysis, energy consumption**, and benchmarking analysis;
9) Power station operation benefit analysis, boss report.
The economic benefit analysis mainly relies on the modeling of the energy management system, and the operation efficiency of the whole system is obtained for the output of the PCS and the SOH of the energy storage system.
The container design is mainly based on the environmental conditions of the project, such as climatic conditions, altitude, etc., and carries out targeted design.
It mainly includes the aspects covered in the following table:
The main parameters of the container are as follows:
The design of the container system needs to be able to ensure that the container has good anti-corrosion, fireproof, waterproof, and other related functions, and the container design has the following characteristics.
Grounding designThe container is supplied with a grounding copper bar. The grounding copper bar can be reliably connected with the non-functional conductive conductor of the whole container (the metal shell of the container that is not charged under normal circumstances, etc.), and at the same time, the container provides the user with 2 grounding points that meet the requirements of the most stringent electrical standards in the form of copper bar, and the grounding point provided to the user must form a reliable equipotential connection with the non-functional conductive conductor of the whole container, and the grounding point is located at the diagonal position of the container. Non-functional conductive conductor grounding points. The partial view of the grounding copper bar is shown in the figure below
Lightning protection design**The road is equipped with an anti-surge protection module, and an auxiliary alarm switch, in case of lightning strike, it can send an external alarm signal through the monitoring platform. The monitoring system monitors the lightning protection signal in real time, and once an alarm occurs, the system automatically switches to the corresponding monitoring interface, and at the same time generates alarm events and corresponding processing prompts. The lightning protection system is connected to no less than 2 grounding copper bars provided by the container to the user by means of grounding flat bars or grounding round bars. Lighting system designIt can realize the control of the lighting in the container, and the lighting has the function of vandalism, providing a safe lighting environment for the monitoring inside the container. Managers can manually switch the lights on site to control the lights. In addition, at least 5 emergency lights are installed in the container, and once the system is powered off, the emergency lights in the container will be put into use immediately, and the effective illumination time of a single emergency light will not be less than 30 minutes within 5 years. Security and alarm system designThe container has an alarm system, which can provide more obvious information to the outside world by installing an alarm light in a special position, so as to play an early warning role. The container is equipped with smoke sensors, temperature sensors, humidity sensors, emergency lights, door magnetic switches, fire extinguishers, lightning protectors and other essential safety equipment, smoke sensors and temperature sensors and control switches of the system form an electrical interlock, once the environmental parameters are detected beyond a reasonable range, the door magnetic switch alarm, fire extinguisher start, lightning alarm, etc., immediately cut off the running battery complete set of equipment, and carry out sound and light alarm, and upload the data to the remote monitoring platform through the battery management system, Carry out remote alarm monitoring. 
Diagram of container alarmFire protection system designThe fire protection system is composed of smoke detectors, temperature detectors, sound and light alarms, and fire extinguishers, and the container system is monitored in real time through the environmental monitoring system.