1. Technical specifications
Technical specifications
The BMS Main 3 device is a modular battery management system (BMS) controller and performs the following functions:
- collection of information about the voltage and temperature of battery cells from BMS Logic devices;
- measurement of current through the battery;
- battery protection by opening the charge and discharge circuits in case of overcharge, deep discharge, short circuit, overheating, overcooling of the battery and under other conditions;
- determination of the battery state (state of charge, state of health, effective capacity, internal cell resistance, etc.);
- battery cell balancing control;
- communication with other devices (charging station, display panels, vehicle controller, etc.).
The BMS Main 3 device is flexibly configured and can work with various types of lithium-ion batteries: LFP (LiFePO4 and LiFeYPO4), LCO (LiCoO2), LMO (LiMn2O4), NMC (LiNiMnCoO2), NCA (LiNiCoAlO2), LTO (Li4Ti5O12), etc.
Specifications
| Parameter | Value |
| Power supply | |
| Supply voltage, V | 9 to 32 |
| Current consumption at supply voltage 24 V, mA, max | 150 |
| KEYRUN or CHARGE_ON signal for turning on the device, V, min | 8.5 |
| Scalability | |
| Number of connected BMS Logic devices, max | 40 |
| Number of controlled cells, max | 720 |
| Controls | |
| Number of programmable switches for controlling contactors (9-32V, 2.5A) | 6 |
| Number of programmable discrete inputs (dry contact) | 6 |
| Number of programmable discrete inputs 9-32V | 2 |
| Number of programmable discrete outputs (open drain, 40V, 1A) | 4 |
| Sensors | |
| Number of connected current sensors (two signal lines for each sensor) | 3 |
Error in measuring signals from current sensors, V, max At ambient temperature 25 ± 5 ºС | 0.001 |
| Current sensor types | Bidirectional with 5V supply voltage (LEM series HASS, HTFS, DHAB or analogues) |
| Number of high voltage measurement inputs (two signal lines for each input) | 2 |
| High voltage measurement range, V | 10 to 1000 |
| High voltage measurement error, V, max | ± 2 |
| Number of connected external temperature sensors (100 kOhm NTC-thermistors) | 2 |
Temperature measurement error using external temperature sensors, ºС, max In the measurement range from -20 to +85 ºС | ± 2 |
| Temperature measurement error using a built-in temperature sensor, ºС, max | ± 2 |
| Humidity measurement error using a built-in humidity sensor, %, max | ± 10 |
| High-voltage interlock loop (HVIL) | |
| Current in the HVIL, mA, typical | 25 |
| Total resistance in the HVIL, Ohm, max | 200 |
| Interfaces | |
| Number of USB interfaces | 1 |
| USB speed, Mbit/s | 12 |
| Number of CAN interfaces | 3 |
| CAN speed, kbit/s | 125, 250 (by default), 500, 1000 |
| Number of RS-485 interfaces | 2 |
| RS-485 speed, bit/s | 600, 1200, 2400, 4800, 9600 (by default), 19200, 38400, 57600, 115200 |
| Output voltage of CAN2 power supply, V | 5.0 ± 0.5 |
| Output current of CAN2 power supply, mA, max | 400 |
| Connecting an additional expansion interface module | BMS Wi-Fi, BMS GSM, BMS LANmodule |
| Headers X1-X9 type | Hirose ZE05 |
| Headers X11-X14 type | Molex series Micro-Fit |
| Galvanic isolation | |
Rated insulation voltage, VRMS, min Conditions: duration 1 minute, AC 50 Hz, 1) between connectors of CAN1, RS-485-1, discrete inputs/outputs interfaces and device power circuits, 2) between connectors of CAN1, RS-485-1, discrete inputs/outputs interfaces and high voltage measurement circuits, 3) between the device power supply circuits and the high voltage measurement circuits | 3500 |
| Weight and overall dimensions | |
| Overall dimensions (length × weight × height), mm | 200 × 123 × 12 |
| Weight, g, max | 160 ± 5 |
| Operating conditions | |
| Operating temperature range, °С | -40 to +85 |
Overall and mounting dimensions
Description of features
The BMS Main 3.0 device is powered from an external source having an output voltage in the range from 9 to 32V (connector X1). The device is turned on when there is power and the KEYRUN or CHARGE_ON signal is supplied with a level of at least 8.5V.
Up to 40 measuring devices BMS Logic 12, BMS Logic 18, BMS Logic RET (X9 connector) can be connected to BMS Main 3.0, while the maximum battery voltage can reach 3000V (assuming that 720 cells are connected with a maximum voltage of 4.2V).
The BMS Main 3.0 device can control 6 contactors (connector X2). For control, intelligent keys are used that monitor the switching current and their own temperature, generating a high-level voltage to power the contactor windings.
To control battery operating modes, BMS Main 3.0 provides 8 discrete inputs (connector X3), two of which detect voltage in the range from 9 to 32V, the other six are connected to outputs of the “dry contact”, “open collector” or “open drain” type and detecting a short circuit of the signal input to the virtual ground of the device.
The BMS Main 3.0 device has additional 4 open-drain discrete outputs (connector X3) for issuing control commands to an external circuit.
Up to 3 current sensors with unipolar +5V power supply and two signal lines (connector X5) can be connected to BMS Main 3.0. The device is compatible with LEM sensors of the HASS, HTFS, DHAB series or similar from other manufacturers. Using two or three current sensors, a complex battery system can be implemented (for example, an inverter power system with a midpoint and monitoring the current in each of the two battery segments).
The device has 2 channels for measuring high (up to 1000V) voltage (connectors X11-X14). Using these channels to measure the voltage on the power bus before the contactors and after the contactors, the device controls the process of precharging the capacitors in the load and determines the welding (sticking) of the contacts of the power contactors.
Two external thermistors (connectors X5) can be connected to BMS Main 3.0 to measure the temperature in the battery container and/or the temperature of the power contactor. The device software allows to configure the protective opening of the contactor when it overheats.
The device continuously monitors its own temperature and humidity of the surrounding air using built-in sensors. The BMS Main 3.0 software allows you to configure the protective opening of all contactors at critically high ambient humidity.
The device implements a circuit for active monitoring of the integrity of a high-voltage bus (high voltage interlock loop, HVIL). BMS Main 3.0 outputs a modulated signal into the current loop and controls the current value in it (connector X4). If there is a discrepancy between the measured and required current values, the device opens the power contactors.
The BMS Main 3.0 device has the following interfaces:
- USB – used to configure device parameters using the ElectricDeviceMonitor software;
- CAN1 – used for communication with external equipment (charging station, vehicle controller, etc.);
- CAN2 – used to configure device parameters using the ElectricDeviceMonitor software and for communication with indication devices BMS Indication, BMS Display;
- CAN3 – used for communication with other battery controllers (in battery systems consisting of several batteries connected in parallel), as well as with next generation BMS Logic devices;
- RS-485-1 – used for communication with external equipment via the Modbus RTU protocol;
- RS-485-2 - used for communication with current generation BMS Logic devices.
On the device board there is a P2 connector for connecting an expansion communication module: BMS Wi-Fi, BMS GSM or BMS LANmodule. With these modules, user can configure device parameters using the ElectricDeviceMonitor software and transfer accumulated log files with the state of the battery system to a remote server.
The device can be used as a controller of several battery modules connected in parallel and controlled by other BMS Main 3 devices. To do this, install modified firmware that changes the device type to BMS Main 3X.
Typical battery system diagram
Figure below shows an example of a functional diagram of a vehicle battery.
The following are connected to the BMS Main 3.0 device:
- external power supply 9-32V – contacts X1.8 (VIN), X1.2 (GND), X1.3 (KEYRUN);
- 4 BMS Logic 12 measuring devices – contacts X9.4 (LOGIC_5V), X9.3 (GND), X9.2 (LOGIC_A), X9.1 (LOGIC_B);
- Hall-effect current sensor, for example, HASS 300-S – contacts X5.1 (CS1_5V), X5.2 (GND), X5.7 (CS1_IN1), X5.8 (CS1_REF_IN2);
- precharge contactor – control contacts X2.5 (CONT1_OUT), X2.1 (GND);
- main contactor (battery minus) – control contacts X2.6 (CONT2_OUT), X2.2 (GND), feedback contacts X3.9 (DIN1_SIGNAL), X3.1 (DIO_GND);
- combined charge-discharge contactor (battery plus) – control contacts X2.7 (CONT3_OUT), X2.8 (GND), feedback contacts X3.10 (DIN2_SIGNAL), X3.2 (DIO_GND);
- high-voltage bus before contactors – contacts X11.1 (IN1+), X12.1 (IN1-);
- high-voltage bus after contactors – contacts X13.1 (IN2+), X14.1 (IN2-);
- vehicle controller – contacts CAN1 bus X6.1 (CAN1_H), X6.2 (CAN1_L), X6.3 (CAN1_RS485_1_GND).