SAT BMS User Guide Rev001. 2015.11
CONTENTS 1 SAFETY... 3 1.1 General guidance... 3 2 SAT BMS Introduction... 4 2.1 General overview... 4 2.2 BMS General wiring structure... 4 2.3 Hardware... 4 2.4 Program... 5 3 MBMS (Master Battery Management System)... 6 3.1 MBMS general overview... 6 3.2 MBMS wiring structure... 6 3.3 MBMS function... 6 4 SBMS (Slave Battery Management System)... 9 4.1 SBMS general overview... 9 4.2 SBMS wiring structure... 9 4.3 SBMS function... 9 5 PIB (Power Interface Board)... 10 5.1 PIB general overview... 10 5.2 PIB wiring structure... 10 5.3 PIB function... 10 6 User programmable interface... 11 6.1 General function... 11 6.2 Installation to PC... 11 6.3 GUI structure... 11 6.4 User screen.... 12 Appendix A. SAT BMS Specification... 16 Appendix B. SAT BMS Protocol... 16 Appendix C. SAT BMS Layout... 19
1 Safety 1-1 General guidance The BMS must have a way of shutting off any connected charger, load, source or any other means of charge and discharge. The SAT BMS has a safety signal in operating mechanism to turn off the system, turning off signal activate when following occurs. Over the limit of cell voltage and current and Temperature Under the limit of cell voltage and current and Temperature When BMS intercommunication error occurs When User change the program parameter The voltage tap connectors must be DISCONNECTED from the BMS when being wired or when wiring is being modified for personal safety and to prevent damage. Immediately disconnect the BMS from the battery if the BMS is damaged. Always verify voltage taps and current sensor wires are wired correctly before plugging them into the SAT BMS to do so may result in damage to the BMS. Damaged units should be immediately disconnected from all power including the battery pack and removed from service. Never continue to use a damaged BMS unit. It is very important, both for safety and for the health of the BMS, that all cell tap wires are always disconnected before any modifications are made to the wiring of the battery pack. We recommend designing the battery box enclosure to require the cell taps to be disconnected before the battery wiring can be modified or applying warning stickers throughout the battery pack indicating that the BMS must be disconnected before the battery pack is serviced. It is strongly recommended to use the validation tool to verify cell tap wiring before plugging the harness into the SAT BMS as it is very easy to make an error wiring the harness, and errors may not be obvious. Care must be taken not to short any pins with the multimeter. Personal safety equipment including protective eye-wear and gloves and arc-flash resistant clothing should be worn for protection in the event of an arc flash.
2 BMS Overview 2.1 General Overview The SAT BMS Systems is designed to manage and protect Lithium ion battery packs and is suitable for use in stationary energy storage such as network control for distributed generation type of Frequency regulation application. The SAT BMS is designed for maximum 240 in series to obtain pack voltages up to 1,000V. 2.2 BMS General Wiring Structure 2.3 The SAT BMS include following hardware components MBMS (Master Battery Management System) SBMS (Slave Battery Management System) PIB (Power Interface Board) (option to provide only for 5kW system) Display panel LED Indicator Connector and wiring components
2.4 The User Interface Program protects and monitors a battery pack by monitoring sensors and using outputs to control charge and discharge into the battery. MBMS > Maintains and controls the Status of Battery [Temperature, Voltage, SoC%, Ah]. > Measure system voltage and current. > Communicate to PMS or EMS. > Monitor and collect SBMS information. > Send the status to the Display and LED on demand. > Controls the Power Interface Board. SBMS (Slave Battery Management System) 2.5 Wiring interconnection > Sense Battery s Voltage and temperature. > Execute Cell balancing (Passive). > Transfer the collected data to MBMS.
3 MBMS (Master Battery Management System) 3.1 MBMS is designed to maintain and control the battery pack with primary functions as follows.. Collects the Battery s general information by CAN communication. Calculate the condition for Cell balancing and convey the result into Slave BMS. Calculate the total current to sync with SoC (%). Display the battery pack status on the front panel. Report the BMS status to high level of system control. i.e PMS OR EMS. Feedback the battery pack condition to control the relay for each DC battery and DC battery pre-charge and AC source and cooling fan. 3.2 MBMS Wiring Structure 3.3 MBMS Function 3.3.1 Basic Operations Measures total battery pack current - The Master BMS uses an inline shunt resistor to measure current.
When current runs through the shunt resistor, a small voltage drop is produced. The BMS measures this small voltage drop to calculate the current flow. - It is designed to use shunt resistor rating with ±25mV, ±50mV, ±75mV and available up to with ±500mV. - The current sensor - wire should be on the side of the current sensor connected to the negative terminal of the battery and the current sensor + side should be connected to the load side of the sensor. - The Master BMS is specially designed to use Kalman filter to measure current and eliminate noise during reading current. Measures total Pack Voltage - Maximum input voltage is available up to ±1,000V Measure SoC % and Amperage - The Master BMS calculates a battery pack s state of charge (SOC) primarily by coulomb counting track of how much current has entered or left the battery pack. - The Master BMS collects current data every 100ms and calculate to convert with a battery pack s state of charge (SoC%). Drafting Point - The Master BMS is specially designed and optimized to the type of Lithium Ion Phosphate (LiFePO4) cell, it has wide flat zone in cell voltage reading as a feature of cathode materials on it so that it allows a bit tolerance of precise reading in SOC. - FiFePO4 discharge characterization - So, it carry out to point out the deep shape range of cell voltage and initialize those points to calibrate SoC(%). - The program compensate SoC(%) from maximum 8 available reading points.
3.3.2 Charge and discharge The Master BMS read the charge and discharge mode by the direction of input current. When current read +, then it read discharge and reverse reading to charge. During charge mode, when the Master BMS read above the limit of current and each cell voltage, SoC(%) then the Master BMS shuts off the system by open the system relay and after while the system will be stand by automatically according to reactivated condition. During discharge mode, when the Master BMS read below the limit of current and each cell voltage, SoC(%) then the Master BMS shuts off the system by open the system relay and after while the system will be stand by automatically according to reactivated condition. 3.3.3 Cell voltage channel capability Only one Master BMS allows to connect up to 10 Slave BMS and 10 Slave BMS allows to connect up to 240 cell channel. 3.3.4 Display and LED indicator The BMS display the current battery pack status with LCD panel. - 1 st line display battery pack status with charge, discharge, error mode and 2 nd ~4 th line : status of voltage, current, temp, SoC LED color indicates the status of current battery pack. LED color RED GREEN ORANGE RED flicker LED OFF Status Stand by Charge Discharge Error BMS off 3.4 Wiring Connection
4 SBMS (Slave Battery Management System) 4.1 General function The Slave BMS receives each cell voltage on battery pack and pack temperature, generally execute cell balancing with user conditions. The Slave BMS has dual LTC6803-4 and each connect up to 12 channels and dual up to 24 channels. 4.2 SBMS wiring structure 4.3 SBMS Function 4.3.1 General operation The Slave BMS report cell voltage and temperature to Master BMS every 500 ms. The Slave BMS read and analyze cell voltage every 200 ms and perform cell balancing by user condition. 4.3.2 Cell balancing in charge Start balancing when cell voltage is above the limit of starting point which user set. Start balancing when each cell voltage gap is above the limit. 4.3.3 Cell balancing in discharge Even discharge, cell balancing works like charge mode when cell voltage is above the limit of starting point which user set it. Cell balancing is stop when it reaches to the start point. 4.3.4 Great caution when in wiring to battery pack As a specification of LTC6803-4, pack voltage should be above at least 10V to operate BMS system.
4.4 Voltage Tap Connection Meanwhile, each LTC6803-4 require to connect above at least 4 channel above 10V, when in connecting below 10V and 4channel then BMS doesn t work properly. 5 PIB (Power Interface Board) (Option to provide only for 5kW system) 5.1 PIB overview Power Interface Board provide the controllable DC power to the Master BMS and Slave BMS using power transformer both AC grid and Battery pack DC power, temporarily PIB contains one of AC contactor as an option. 5.2 PIB Structure 5.3 PIB function 5.3.1 Power supply The PIB converts AC grid power with 90V~264V into DC 48V by SMPS device. In case of Emergency case, the PIB trigger the power source from AC grid to
battery pack DC source to retain the SAT BMS system. There is DC-DC converter that change the source power from AC and DC to DC 12V connecting to Master BMS and slave BMS. 5.3.2 Surveillance AC grid power The PIB sense AC input power and make sure to keep continuous output power supply to the SAT BMS. 6 User programmable Interface 6.1 General function User program is able to input the operating condition and run to operate system, when user want to modify the operating conditions, it also able to edit and save the conditions in Master BMS and Slave BMS and recall the saved condition whenever connecting to user program. Detailed operation and setup program is referred to the operation manual. 6.2 Installation to PC 6.2.1 PC condition to installation the program PC installation is generally tested in window OS bas and the SAT BMS is required to above Window 7.0 to run the user program. PC preparation: JRE framework is required to be installed prior to install the BMS user program. Connection type : Serial Port ( RS-232C ) 6.3 GUI(Graphical User Interface) structure
6.4 User Screen Initial mode to connect BMS Configuration screen - General
Configuration screen - Cell Configuration screen - SoC
Dashboard Screen Live cell screen
Message screen SAT BMS User Guide Rev01.
Appendix A. SAT BMS specification Item Spec. description Input / Output Input Power 12V, 4.2A Input Commu CAN bus, 2ea Site Controller, SBMS Bi-direction Nication RS-232c for debug Bi-direction Total Battery Voltage Input Data Total Current with Shunt Res. Input Reading Every Cell Voltage from SBMS, 24ch, on CANBUS Input Battery Temp from SBMS, 4ea Input Display Status of Running Output & LED Status of Fault Output GPIO for DC Contactor, 2ea Main, Pre-charge Output Controls GPIO for AC Contactor for PS, 2ea GPIO for FAN, 1ea Output Output Appendix B. SAT BMS protocol Item Protocol description Read/Write Unit Type Total Voltage Read V Float Cell Voltage Read V Float Total Current. Read A Float Temp. Read Float Information Controls General Control Configuration SoC (%) Read % Float SoC (Ah) Read Ah Float Charge limit Voltage Read V Float Discharge Limit Voltage Read V Float Charge limit Current Read A Float Discharge Limit Current Read A Float SoH Read % Float Cell Internal Resistance Read Ohm Float RMS Battery Current Read A Float Status Code Read Number Integer DC Main Contactor On/Off Read/Write On/Off Integer DC Pre-charge Contactor On/Off Read/Write On/Off Integer AC Contactor On/Off Read/Write On/Off Integer FAN On/Off Read/Write On/Off Integer Power-Down or Sleep Mode Read/Write Sleep/Active Integer General Cell Capacity Read/Write Ah Float Cell Number of Serial connection Read/Write Number Integer Bus-bar Resistance Read/Write Ohm Float Cell Number of Parallel connection(pack Read/Write Number Integer capacity, Ah) Shunt Resister value or type Read/Write Ohm TBD
Pack Voltage mismatch Threshold Read/Write V Float Voltage Cell Max Limit Voltage at charging Relay Read/Write V Float Open Cell Charge Re-Enable Time Relay Close Read/Write sec Float Cell Charge Release Voltage Relay Close Read/Write V Float Cell Max Charge Time Read/Write min Float Cell - Min Limit Voltage at discharge Relay Read/Write V Float Open Cell Discharge Re-Enable Time Relay Close Read/Write sec Float Cell Discharge Release Voltage Relay Close Read/Write V Float Cell Max Discharge Time Read/Write min Float Current Charge Current Limit Read/Write A Float Discharge Current Limit Read/Write A Float Reverse Current Sensor Read/Write FW/REV Integer Peak charge current limit Relay Open Read/Write A Float Charge current limit Relay Open when delay Read/Write A Float time s up Time delay before charge current limit Read/Write msec Integer Cell Balancing Cell - Balancing Delta voltage Balancing Gap. Read/Write V Float Cell Start Balancing Voltage Read/Write V Float Cell Minimum Balance Voltage Read/Write V Float Temp. Charging temp upper limit Read/Write Float Charging temp lower limit Read/Write Float Discharging temp upper limit Read/Write Float Discharging temp lower limit Read/Write Float Fan Enable Temp. Read/Write Float SoC SoC charged % Read/Write % Float SoC discharged % Read/Write % Float SoC Draft Point Read/Write %, Number TBD
Appendix C. SAT BMS Layout Master BMS(mm) Slave BMS(mm)