I. Project Overview
1. Project Background
While automobiles have brought development to the national economy and convenience to mankind, they have also brought enormous disasters. 42% of environmental pollution comes from emissions from gasoline-powered vehicles, and 80% of urban noise is generated by transportation. The world's oil reserves are decreasing day by day, and gasoline-powered vehicles are major consumers of oil! Therefore, the development of the automobile industry today must seek the direction of low noise, zero emissions, and comprehensive energy utilization.
Currently, under the dual constraints of energy crisis and environmental protection, the country is actively developing the electric vehicle industry, and electric vehicle charging and swapping stations are the most critical supporting link. As electric new energy vehicles are the future direction of automobile development, the completeness of charging facilities is directly related to whether they can be promoted on a large scale.
The charging and battery swapping station monitoring system is an important component of electric vehicle charging and battery swapping stations. It can perform real-time data monitoring of the charging status of new electric vehicles, obtain real-time information on the operation of each charging box, detect the status of each battery in real-time, and issue alarms for abnormalities in the status of charging boxes, battery packs, etc.
2. Construction Goals
The charging monitoring system plans to complete the data collection and monitoring of chargers, batteries, and battery swapping robots at subordinate charging stations.
The system performs the following functions:
Data collection and storage of relevant parameters for various chargers, batteries, and battery swapping robots.
Monitoring of key parameters and main process screens for each charger, battery, and battery swapping robot.
Statistics and analysis of key parameters of various chargers, batteries, and battery swapping robots.
Trend charts, pie charts, and bar charts are used to display the main parameters of each charger, battery, and battery swapping robot.
Daily, monthly, quarterly, and annual reports on the main parameters of each charger, battery, and battery swapping robot.
The coordinated control of various chargers, batteries, and battery swapping robots.
Records of charging and battery swapping information and events for each charger, battery, and battery swapping robot.
The entire system is web-based, allowing users to access it anytime, anywhere through user authentication.
The entire system has excellent scalability and elasticity, allowing for seamless and low-cost integration of any newly added monitoring centers.
The entire system has batch management capabilities and enables seamless integration with SQL Server relational databases.
3. Technical difficulties
The charging equipment is a new type of equipment, and there is no unified standard for the communication protocol. The monitoring software needs to be able to be adjusted and updated according to the equipment protocol to facilitate system maintenance.
Each charger and charging robot works independently, making it difficult to coordinate their work and resulting in waste.
The monitoring system requires a high degree of real-time performance, accuracy, and reliability in equipment control, and strict restrictions must be placed on the operation of the equipment.
The monitoring system needs to have expansion capabilities to facilitate system upgrades;
The charging station operation and management system generates a large amount of data, making analysis difficult.
II. System Design
To achieve comprehensive monitoring of electric vehicle charging and battery swapping stations, ForceControl Technology developed a large-scale electric vehicle charging and battery swapping station monitoring system based on the pspace platform, which has been successfully applied to a large electric bus charging and battery swapping station in Beijing. The system mainly consists of three parts: a charging system, a battery swapping system, and a power distribution system.
1. Charging System
Real-time data acquisition: The charger communicates with the battery management system (BMS) built into the battery box via the CAN bus to obtain battery status and operating information. Through the CAN-to-Ethernet module, the data is converted into Ethernet and communicated with the station-level control layer equipment. Data acquisition includes charger operating status, temperature fault signals, power, voltage, current, and charge; battery pack temperature, state of charge (SOC), voltage, current, and battery fault signals.
Charging system operation monitoring: configuration of charger and battery group, monitoring of operation information of four workstations, operation monitoring of one-to-one and one-to-two chargers, operation monitoring of battery racks, and operation monitoring of charging cabinets.
Report data query: Charger charging information query, battery pack charging information query, charging process related information, charger event query, battery box event query.
Curve data query: The monitoring system can display real-time/historical curves, bar charts, etc. of the charging process data.
Alarm data storage and retrieval: Provides graphical, text, and audio alarms, along with corresponding alarm handling functions, for charger operation and abnormal information. Alarm events related to system operation can be printed on the event printer, and the system automatically displays associated alarm and event screens.
Event logging: Records charger start/stop operations, charger malfunctions, abnormal charging parameters, and abnormal battery pack parameters. Events such as charger status changes, output voltage and current exceeding limits, battery pack malfunctions, and charger start/stop operations can be categorized and displayed by time, type, and charging device, with corresponding alarm information. Real-time engineering values and corresponding statistical values can be recorded at set intervals, generating a historical database.
2. Battery swapping system
Real-time data acquisition: The battery swapping system performs real-time status monitoring of all involved equipment, such as chargers, charging racks, charging compartments, battery boxes, battery storage, batteries, robots, and swapping tracks, to monitor the battery swapping process in real time. Equipment uploads relevant information to the backend monitoring system via Ethernet interface and receives instructions from the backend monitoring system. The backend monitoring system can collect operational status information, location information, and fault information of the swapping equipment.
Battery swapping system operation monitoring: Displays the status of each battery box in each group after grouping, the time to complete full charge, and the status and location information of the swapping robot. Operation and maintenance personnel can issue battery replacement commands. Manually entered information can be displayed during the manual setup process. Appropriate prompts should be provided in case of malfunctions.
Report data query: Battery swapping event report.
Alarm data storage and retrieval: Records battery replacement operations and related equipment anomalies in the battery swapping system, providing graphical, text, and audio alarm methods and corresponding alarm handling functions. Alarm events related to system operation can be printed on the event printer, and the system automatically displays associated alarm and event screens.
3. Power distribution system
Real-time data acquisition: Collects information such as switch status, protection signals, and energy metering information of the power supply system of charging stations/battery swapping stations. It collects data including 10kV bus voltage, 10kV incoming and outgoing lines and A, C phase and zero-sequence currents, DC bus voltage, 380V bus voltage, 380V incoming three-phase current, 380V outgoing single-phase current; transformer active power, reactive power, power factor, active energy, transformer load rate, and 380V outgoing active energy.
Power distribution system operation monitoring: main wiring diagram, real-time data tables, load curves, voltage bar charts, pie charts and system operating condition diagrams.
Alarm data storage and retrieval: Provides graphical, text, and audio alarms, along with corresponding alarm handling functions, for remote control operations of the power distribution system and abnormal information from related equipment. Alarm events related to system operation information can be printed on the event printer. The system automatically displays associated alarm and event screens.
III. System Architecture
The backend system monitoring center uses two soft-redundant servers as front-end servers, deploying two sets of ForceControl pspace standard network version software. This is primarily used for real-time data acquisition from various charging and swapping devices. Two hard-redundant servers serve as historical servers, deploying two sets of ForceControl pspace software. This is mainly used for secondary processing of real-time data from the front-end servers (such as statistical calculations) and for historical data storage. Related service programs on the data servers receive real-time data sent from the (primary or backup) front-end servers, process it, and save it to a local commercial database, while also providing data sources for the monitoring workstations.
The monitoring workstation is primarily used to display real-time operating status data of various charging and swapping devices. On-duty monitoring personnel can also remotely operate certain charging and swapping devices from their local machine. The monitoring workstation sends real-time data requests to the front-end in real time. When querying historical data, it sends the query command to the historical data service program on the data server. This program then queries historical data stored in the commercial database on the data server and returns the results to the client program on the monitoring workstation. The client program is responsible for displaying the query results.
IV. System Functions
1. Real-time data acquisition
Real-time data collection was completed for all chargers, battery boxes, battery swapping robots, smoke alarms, and other equipment. The data volume reached 100,000 points.
2. Historical data storage
Historical data storage of key parameters for equipment such as chargers, battery boxes, and battery swapping robots has been completed. The number of historical data points has reached 40,000.
3. Grouping settings for chargers and battery boxes
This system enables arbitrary configuration of charger and battery box groups, effectively resolving situations where the entire charging equipment becomes unusable due to hardware failure of individual chargers or battery boxes. This improves equipment utilization. In the event of a failure in individual devices, the system can promptly switch to backup equipment, enhancing overall system efficiency.
Grouped display interface:
Group configuration interface:
4. Charger and battery box data display
The system enables real-time data display for hundreds of chargers. By fully utilizing the interface template functionality of the ForceControl Pspace series software and employing variable substitution, it allows users to view data from hundreds of chargers through a single configured interface. This shortens the software development cycle and reduces the operational burden on the monitoring host.
Charging cabinet status display:
Battery rack status display
Running status group display:
Charger details displayed:
5. Data report query
1) Charger charging query report:
Reporting function: Query charging information by charger
Report content: workstation number, charging cabinet number, charger number, charging start time, charging end time, battery pack number, battery box number 1, starting SOC, ending SOC, battery box number 2, starting SOC, ending SOC.
Search criteria: Workstation number (1-4, all)
Charging cabinet numbers (1-32, all)
Charger serial number (1-120, all)
Start time (charging start time >= start time)
End time (charging end time <= end time)
Generation conditions: A record is generated when charging begins and completed when charging ends (including normal end and fault end). If communication is interrupted, it is necessary to determine whether the charger was in a charging state before the communication interruption. After communication is restored, it is necessary to determine whether it is still in a charging state. If it is in a charging state, it is assumed that the charging process before the communication interruption is continued. Otherwise, the current time is recorded as the charging end time.
2) Battery box charging query report:
Reporting function: Query charging information by battery pack number
Report content includes: battery pack number, battery pack serial number, charging start time, charging end time, starting SOC, ending SOC, charger number, and vehicle license plate number.
Search criteria: Battery pack number (1-N, all)
Battery box numbers (1-8, all)
Start time (charging start time >= start time)
End time (charging end time <= end time)
Generation conditions: A record is generated when charging begins and completed when charging ends (including normal end and fault end). If communication is interrupted, it is necessary to determine whether the charger was in a charging state before the communication interruption. After communication is restored, it is necessary to determine whether it is still in a charging state. If it is in a charging state, it is assumed that the charging process before the communication interruption is continued. Otherwise, the current time is recorded as the charging end time.
3) Charger Event Query Report
Reporting function: Query charger events (fault start, fault reset / user operation (start, stop)).
Report content: Workstation number, charging cabinet number, charger number, event time, event details, current user.
Search criteria: Workstation number (1-4, all)
Charging cabinet numbers (1-32, all)
Charger serial number (1-120, all)
Start time (event occurrence time >= start time)
End time (event occurrence time <= end time)
Generation conditions: A record is generated when the event occurs.
4) Battery Box Event Report
Reporting function: Query battery box faults (fault onset, fault reversal).
Report content: Battery pack number, battery pack serial number, event time, charger serial number, event details, current user.
Search criteria: Battery pack number (1-N, all)
Battery box serial numbers (1-8, all)
Start time (event occurrence time >= start time)
End time (event occurrence time <= end time)
5) Battery swapping event report
Reporting function: Query robot events (battery swap start, battery swap end, fault start, fault recovery).
Report content: workstation number, robot number, event time, event details, current user.
Search criteria: Workstation number (1-4, all)
Robot number (1, 2)
Start time (event occurrence time >= start time)
End time (event occurrence time <= end time)
Generation conditions: A record is generated when the event occurs.
Report query display interface:
6. Data Curve Query
The interface is divided into three sets of curves: charger curves (charger voltage and charger current); first box voltage curves (individual cell voltage); and second box voltage curves (individual cell voltage). All battery box voltage curves must be freely combinable (the number of curves and their numbers are optional).
Curve query display interface:
V. Project Summary
The application of ForceControl's PSpace series software in a large bus charging and battery swapping station successfully solved the problem of the inability to freely configure charger and battery box groups, enabling flexible configuration of charger and battery box groups. It also resolved the issue of the entire equipment becoming unusable due to the failure of a single charger or battery box. When a charger or battery box fails, the software can be used to flexibly switch to a backup device, shortening equipment maintenance time and improving equipment utilization.
The use of interface templates solves the problem of numerous identical interfaces consuming system resources. Through the pspace interface template function, it is possible to display different charger data through a single interface template, reducing the number of screens by 80% and improving system operating efficiency.
Based on the needs of on-site staff, various data and event reports were specifically created to facilitate on-site staff in promptly understanding the overall operational status of the charger, battery box, and vehicle.
