1. Energy storage system scheme
1.1 Allocation scheme of the energy storage system
The whole energy storage system adopts a lithium iron phosphate battery as the physical carrier of energy storage, takes 126KW h energy battery cluster as the unit, and forms 505KW h battery energy storage system.
The configuration table of the 500K W h energy storage system is as follows:
| order number | project description | burst mode | rated voltage （V） | rated capacity (Ah) | Storage of electricity （kWh） | Implementation method |
| 1 | The cell | 3.2 | 105 | 0.336 | A single cell | |
| 2 | module | 2P6S | 19.2 | 210 | 40.32 | Cell 2 and 6 strings |
| 3 | battery pack | 2P17S | 54.4 | 210 | 11.424 | 3 Module series |
| 4 | Battery cluster | 2P188S | 601.6 | 210 | 126.336 | 11 Battery case is connected in series |
| 5 | battery cupboard | 8P188S | 601.6 | 840 | 505.344 | 4 Battery cluster in parallel |
1.2 Layout scheme of battery and high voltage breaking box of energy storage system
The energy storage battery is installed in the battery prefabricated cabin, and four battery racks are arranged in the prefabricated cabin. Each battery rack is installed with 11 battery packs and 1 cluster control control box, and four battery racks are installed with 500KW h, 44 battery packs and 4 cluster control boxes to form the 601.6V 840A h energy storage system.
1.2.1 The overall layout scheme of the 1.2500KW h battery energy storage system is shown in the figure below
1.2.2 Appearance of the battery pack is shown in the figure below
1.2.3 The internal structure of the battery pack is shown in the figure below
1.2.4 Battery cluster is shown in the figure below
1.2.5 Control cabinet is shown in the following figure
2. BMS scheme of energy storage system
2.1 The BMS architecture of the energy storage system
Taking the 500 KWH energy storage system as an example, the BMS architecture is as follows:
explain:
1) Each battery pack is equipped with 1 B C M S (slave control) to collect 17 or 18 unit voltage and 6 temperature signals;
2) 11 battery pack first series of 1 battery cluster, 1 battery cluster equipped with a cluster control box (secondary control), the cluster is responsible for the address of BMU battery box, each string of battery voltage, temperature collection, working current data collection, battery protection relay control and the total voltage calculation of battery, battery fault diagnosis, etc. (including but not limited to the above functions);
Each cluster is equipped with 1 Hall sensor, 1 fuse, 1 total negative relay, 1 charging protection relay, 1, discharge protection relay, 1 precharge relay, 1 pre-charging resistance, 1 high voltage relay power control relay, are installed in the cluster control box;
A battery cabinet is equipped with group control, installed in the control box, which is responsible for collecting the battery information of four cluster control, completing the information interaction with PCS and EMS, and interacting with PCS and EMS through the CAN bus.
2.2 BMS product parameter requirements
1) BMS product parameter requirements
order number | project | qualification |
1 | working power supply | DC24V （9V~36V ） |
2 | Low voltage power consumption | <200W (BMS) |
3 | Voltage sampling | The detection range was 0 to 5 V, error ± 0.5%FS, and error typical values <± 5 mV |
4 | Current sampling | -300A ~ + 300A with error ± 1%FS |
5 | Temperature sampling | The detection range was-40 to 120℃ with error ± 1℃ |
6 | SOC calculation error | ≤5% |
7 | SOH estimation error | ≤5% |
8 | function | With the function of charging control and management, battery system fault diagnosis, battery cell voltage or battery module voltage, battery system temperature detection, over current, over voltage, under voltage protection, SOC estimation, communication with PCS, EMS, battery internal CAN communication, passive balance, thermal management, real-time charge and discharge current detection and real-time maximum charge and discharge power estimation. |
It has the function of self-protection of the battery pack by cutting off the charge and discharge high voltage loop of the battery pack, to ensure that the battery pack does not damage the battery due to overcharge, overtemperature, overdischarge and other abuse conditions. | ||
Manage the software update and upgrade function of the system. | ||
10 | operating temperature range | -35℃～85℃ |
11 | BMS installation site | From the control position: inside the battery box; Cluster control location: cluster control box; group control location: control box; |
12 | Power management | The battery factory provides the parameters according to the battery working parameters, and they can be controlled by the BMS |
13 | There is an external communication interface | 1 CAN communication; 1 ETH communication (Eth communication is group control only). |
2) Technical requirements of the cluster control module
order number | project | parameter | explain |
1 | working voltage | 24V(9V~36V) |
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2 | power dissipation | ＜15W |
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3 | quiescent dissipation | <0.1mA |
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4 | Insulation detection |
| Insulation with PCS |
5 | Current detection | 1 Road | Triitter 1 / 1% FSR / -300A ~ + 300A |
6 | CAN | 3 Road | 1, cluster CAN 0 —— from CAN 0 2, cluster control CAN 1 —— cluster control |
7 | Output drive | 2 Road | Contactor, circuit breaker |
8 | Total pressure detection |
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3) Technical requirements of the group control module
order number | project | parameter | explain |
1 | working voltage | 24V(9V~36V) |
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2 | power dissipation | ＜15W |
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3 | quiescent dissipation | <0.1mA |
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4 | CAN | 3 Road | 1. Level 1 master CAN 0 communicates with two cluster control modules CAN 1 2. Level 1 master CAN 1 communicates with PCS |
5 | Eth | 1 Road | Communicate with the EMS |
6 | drive | 6 Road | 4 Road reserved |
3. Technical requirements of PCS inverter system
3.1 Specific parameters of PCS inverter:
order number | project | parameter | explain |
output rating | 250KW |
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2 | Operating voltage range | 420V dc ～850V dc |
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3 | Maximum AC current | 673A |
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4 | AC output voltage | 400Vac |
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5 | voltage range | 320～460 |
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6 | rated current | 361 |
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7 | Rated output frequency | 50Hz/60Hz | Can set |
8 | Communication connection | 3W+N+PE |
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9 | Output voltage accuracy | 1% | Linear load |
10 | overload capacity | 110% |
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11 | productiveness | 97.5% |
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12 | isolation transformer | possess |
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13 | levels of protection | IP21 |
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14 | operating ambient temperature | -30℃~55℃ |
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15 | relative humidity | 0~95% | No condensation |
16 | cooling-down method | Temperature control intelligent air cooling | Intelligent speed regulation of fan |
17 | Dimension W * D * H (mm) | 1200*800*2050 |
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18 | Weight (kg) | 1582 |
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19 | BMS communication | RS485、CAN |
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20 | EMS communication | RS485、TCP/IP |
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4. Technical requirements of the EMS electric power management system
4.1 Technical parameters
l Input power supply: 1 AC220V (standard), 1 AC220V + 1 D C 400~850V (optional)
l Power consumption: <10W
l CPU: 4-core 2.0G, ARM architecture, 64-bit, domestic production
l Operating system: embedded linux
l MTBF：>50000H
l Storage capacity:> 100GB
l Measurement accuracy: voltage <0.1%; current <0.5%; temperature <0.5℃; time resolution <0.1s
l Number of monitored PCS: <6 units
l Topological circuit: unipolar, bipolar, and chain type
l Ethernet 100M: 2 independent web addresses
l Operating system OS: Linux, SylixOS
l Communication protocol: DL / T101, DL / T103, CAN, MODBUS
l Time synchronization: IRIGB, NTP
l Communication interface: RS485 8, CAN 2;
l IO port: 8 DO, 10DI
l Number of connected air conditioning: <4
l Number of connected electricity meters: <8
l Number of PV connected to the PV inverter: <4
l 4G interface: 1 out of it
4.2 System functions
explain | |
The SCADA system is monitoring | Data display of the key equipment of the whole system, including the topology map, status, alarm information, etc. |
EMS control model | Through this interface, the control mode of energy storage (micro grid) system can be set, including simple modes and intelligent modes. |
BMS supervisory control | Through this interface, you can view the battery attributes, status, information, alarm, SOC, SOH and other data. |
Testing Control of the test | This function is mainly used in debugging, you can configure system level test, single equipment test, such as PCS test, DCDC test, BMS test, air conditioning, heater test, etc. |
The BAS moving ring monitoring | This page can see the power environment data of the energy storage system, and the control and parameters of the test can also be adjusted on this page. |
Tech Indicators Technical indicators | It mainly includes SOH, energy efficiency, PCS efficiency, availability, charge and discharge response and regulation time, battery attenuation rate, etc |
Gateway Data upload | When the energy storage system is connected to other third-party systems, this page can configure the protocol type of the connection, the communication status of the connection, and the command record, etc |
Configure Parameter configuration | Including: the maximum power of the connection point of the energy storage system, whether it supports the reverse power or not, and the working mode configuration of various equipment |
LogMgr Alarm and log | Alarm includes alarm judgment, current real-time alarm, historical alarm |