Lithium iron phosphate storage battery parallel modularized direct current system

Abstract

The invention discloses a lithium iron phosphate storage battery parallel modular direct current system, and belongs to the technical field of direct current power supply. The commercial power access part provides an input power supply through a three-phase four-wire; the input ends of the parallel modular power supply parts are connected with the mains supply access part, and the parallel modular power supply parts are used for providing a direct-current power supply; one storage battery is correspondingly connected with one parallel modular power supply part, and the storage batteries are charged through the parallel modular power supply parts; and the load part is connected with the output end of the parallel modular power supply part. The technical scheme has the beneficial effects that the storage battery and the parallel modular power supply part form a parallel direct current system, so that as long as one line can work normally, the whole loop can be kept in a closed state, stable power supply is realized, and the reliability of the direct current system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of DC power supply, and particularly to a parallel modular DC system for storage batteries. Background Art

[0002] The DC power supply system plays an important role in the field of power supply. It mainly consists of a DC charging panel, a DC power distribution panel, a storage battery panel, etc., and includes components such as an AC power distribution unit, an intelligent high-frequency switching charging module, a storage battery pack, a DC bus automatic (manual) voltage regulating device, a power distribution unit, an insulation fault monitoring device, and an intelligent monitoring unit. These components are all installed in the DC power supply system.

[0003] In the prior art, the intelligent high-frequency switching charging module is divided into a load circuit (combined bus) and a charging (control bus) circuit, and the two are connected by thyristors to regulate the voltage. However, as long as there are any sampling deviations or low consistency in any one or more batteries in the battery pack, it will affect the backup time of the entire system, resulting in the inability to meet the expected power supply duration requirements. Summary of the Invention

[0004] The purpose of the present invention is to provide a parallel modular DC system for lithium iron phosphate storage batteries to solve the above technical problems;

[0005] A parallel modular DC system for lithium iron phosphate storage batteries includes:

[0006] A mains power access section, which provides an input power supply through three-phase four-wire;

[0007] N parallel modular power supply sections, the input ends of the parallel modular power supply sections are connected to the mains power access section for providing DC power;

[0008] N storage batteries, one storage battery is correspondingly connected to one of the parallel modular power supply sections, and the storage battery is charged through the parallel modular power supply section;

[0009] A load section, which is connected to the output end of the parallel modular power supply section.

[0010] Preferably, the mains power access section includes:

[0011] A first AC incoming line switch, the three-phase input end and the neutral input end of the first AC incoming line switch are connected to the power supply;

[0012] The first circuit breaker, the first phase of the input end of the first circuit breaker is connected to the first phase of the output end of the first AC incoming line switch, the second phase of the input end of the first circuit breaker is connected to the second phase of the output end of the first AC incoming line switch, the third phase of the input end of the first circuit breaker is connected to the third phase of the output end of the first AC incoming line switch, and the neutral input end of the first circuit breaker is connected to the neutral output end of the first AC incoming line switch;

[0013] The lightning arrester, the first phase of the input end of the lightning arrester is connected to the first phase of the output end of the first circuit breaker, the second phase of the input end of the lightning arrester is connected to the second phase of the output end of the first circuit breaker, the third phase of the input end of the lightning arrester is connected to the third phase of the output end of the first circuit breaker, and the neutral input end of the lightning arrester is connected to the neutral output end of the first circuit breaker.

[0014] Preferably, the internal circuit connection structures of the N parallel modular power supply units are the same. A single parallel modular power supply unit includes,

[0015] The second circuit breaker, the first input end of the second circuit breaker is connected to the first phase line, and the second input end of the second circuit breaker is connected to the neutral line;

[0016] The parallel power supply module, the first AC input end of the parallel power supply module is connected to the first output end of the second circuit breaker, and the second AC input end of the parallel power supply module is connected to the second output end of the second circuit breaker;

[0017] The third circuit breaker, the first input end of the third circuit breaker is connected to the first DC output positive extreme of the parallel power supply module, the second input end of the third circuit breaker is connected to the first DC output negative extreme of the parallel power supply module, and the first output end and the second output end of the third circuit breaker are connected to the load unit.

[0018] Preferably, one of the parallel modular power supply units is connected to the corresponding one of the storage batteries through a communication interface for CAN communication.

[0019] Preferably, the second DC output positive extreme of the parallel power supply module is connected to the input positive extreme of the storage battery, and the second DC output negative extreme of the parallel power supply module is connected to the input negative extreme of the storage battery;

[0020] The output negative extreme of the (N - 1)th storage battery is connected to the output positive extreme of the Nth storage battery.

[0021] Preferably, the load unit includes,

[0022] Multiple power consumption modules, and one power consumption module is connected between the positive power supply line and the negative power supply line through a DC output switch.

[0023] Preferably, it further includes,

[0024] A fourth circuit breaker, wherein a first input terminal of the fourth circuit breaker is connected to the negative output terminal of the Nth battery, and a second input terminal of the fourth circuit breaker is connected to the positive output terminal of the first battery;

[0025] A first diode, wherein an anode of the first diode is connected to a second output terminal of the fourth circuit breaker;

[0026] A second diode, wherein an anode of the second diode is connected to the anode of the first diode, and a cathode of the second diode is connected to the cathode of the first diode;

[0027] A first fuse, wherein a first end of the first fuse is connected to the cathode of the first diode, and a second end of the first fuse is connected to the load part through a series connection of a second fuse;

[0028] A first ammeter, connected to the first fuse;

[0029] A second ammeter, connected to the second fuse.

[0030] Preferably, it further includes,

[0031] A communication device, wherein the communication device is connected to the load part through a fifth circuit breaker;

[0032] An insulation on-line detection device, wherein the insulation on-line detection device is connected to the load part through a sixth circuit breaker, and the insulation on-line detection device is further connected in parallel with a first voltmeter.

[0033] Preferably, it further includes a monitoring part, and the monitoring part includes,

[0034] A current monitoring module, connected to a communication interface of the parallel modular power supply part, and used for acquiring output current data of the parallel modular power supply part;

[0035] A voltage monitoring module, connected to the communication interface of the parallel modular power supply part, and used for acquiring output voltage data of the parallel modular power supply part;

[0036] A power monitoring module, connected to the communication interface of the parallel modular power supply part, and used for acquiring power data of the parallel modular power supply part;

[0037] An insulation monitoring module, connected to the communication interface of the parallel modular power supply part, and used for monitoring an insulation state of the parallel modular power supply part;

[0038] The main monitoring module is connected to the communication interface of the parallel modular power supply unit, and is used to collect and analyze the monitoring data of the current monitoring module, the voltage monitoring module, the power monitoring module and the insulation monitoring module.

[0039] Preferably, the main monitoring module is connected with a color touch screen, and the color touch screen is used to display the communication information between the main monitoring module and the upper computer in real time.

[0040] The beneficial effect of the present invention is that: by forming a parallel DC system with the battery and the parallel modular power supply unit, as long as one of the lines can work normally, it can ensure that the entire loop remains in a conductive state, achieve stable power supply, and improve the reliability of the DC system. Description of the Drawings

[0041] Figure 1 is the circuit diagram of the lithium iron phosphate battery parallel modular DC system of the present invention;

[0042] Figure 2 is the circuit diagram of the parallel modular power supply unit of the present invention;

[0043] Figure 3 is Figure 1 the partial enlarged view at A1 in

[0044] Figure 4 is the circuit diagram of the load unit of the present invention. Detailed Embodiments

[0045] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0046] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0047] Next, the present invention will be further described in conjunction with the drawings and specific embodiments, but it is not a limitation of the present invention.

[0048] A lithium iron phosphate battery parallel modular DC system, as Figure 1 shown, includes,

[0049] The mains access unit MAI, and the mains access unit MAI provides an input power supply through three-phase four-wire.

[0050] N parallel modular power supply units PMU, the input ends of the parallel modular power supply units PMU are connected to the mains access unit MAI for providing DC power;

[0051] N storage batteries BAT, one storage battery BAT is correspondingly connected to one parallel modular power supply unit PMU, and the storage battery BAT is charged through the parallel modular power supply unit PMU;

[0052] Load unit RL, the load unit RL is connected to the output end of the parallel modular power supply unit PMU.

[0053] Specifically, the present invention provides a lithium iron phosphate battery parallel modular DC system. A parallel DC system is composed of the parallel modular power supply unit PMU and the series-connected storage batteries BAT. The single battery is directly boosted to the DC bus voltage. As long as one of the lines can work normally, it can ensure that the entire loop remains in a conductive state, realizing stable power supply and improving the reliability of the DC system.

[0054] In a preferred embodiment, the mains access unit MAI includes,

[0055] The first AC incoming line switch HZ1, the three-phase input end and the neutral input end of the first AC incoming line switch HZ1 are connected to the power supply;

[0056] The first circuit breaker QL1, the first phase of the input end of the first circuit breaker QL1 is connected to the first phase of the output end of the first AC incoming line switch HZ1, the second phase of the input end of the first circuit breaker QL1 is connected to the second phase of the output end of the first AC incoming line switch HZ1, the third phase of the input end of the first circuit breaker QL1 is connected to the third phase of the output end of the first AC incoming line switch HZ1, and the neutral input end of the first circuit breaker QL1 is connected to the neutral output end of the first AC incoming line switch HZ1;

[0057] The lightning arrester BL, the first phase of the input end of the lightning arrester BL is connected to the first phase of the output end of the first circuit breaker QL1, the second phase of the input end of the lightning arrester BL is connected to the second phase of the output end of the first circuit breaker QL1, the third phase of the input end of the lightning arrester BL is connected to the third phase of the output end of the first circuit breaker QL1, and the neutral input end of the lightning arrester BL is connected to the neutral output end of the first circuit breaker QL1.

[0058] Specifically, the power supply is the mains. The mains controls the connection, load-bearing, and interruption of the current under normal circuit conditions through the first AC incoming line switch HZ1, and closes, bears, and interrupts the current under abnormal circuit conditions (including short-circuit conditions) within a specified time.

[0059] A lightning arrester BL is connected in parallel at the output end of the first AC incoming line switch HZ1. When lightning strikes or overvoltage is generated by power system operations, the lightning arrester BL can effectively release the energy of these overvoltages, thus ensuring that power equipment will not be damaged by instantaneous overvoltages. In addition, the lightning arrester BL also has the ability to intercept and discontinue the follow current, preventing the follow current from causing a system ground short circuit, thus maintaining the stable operation of the power system and further ensuring the safety and reliability of the entire system.

[0060] In a preferred embodiment, referring to Figure 2 , the internal circuit connection structures of N parallel modular power supply units PMU are the same. A single parallel modular power supply unit PMU includes,

[0061] A second circuit breaker QL2, the first input end of the second circuit breaker QL2 is connected to the first phase line A, and the second input end of the second circuit breaker QL2 is connected to the neutral line N;

[0062] A parallel power supply module MK1, the first AC input end of the parallel power supply module MK1 is connected to the first output end of the second circuit breaker QL2, and the second AC input end of the parallel power supply module MK1 is connected to the second output end of the second circuit breaker QL2;

[0063] A third circuit breaker QL3, the first input end of the third circuit breaker QL3 is connected to the positive extreme of the first DC output of the parallel power supply module MK1, the second input end of the third circuit breaker QL3 is connected to the negative extreme of the first DC output of the parallel power supply module MK1, and the first output end and the second output end of the third circuit breaker QL3 are connected to the load part RL.

[0064] Specifically, 4 lithium iron phosphate intelligent parallel modular power supplies (i.e., 4 MK1s) are evenly distributed at the output end of the first AC incoming line switch HZ1 and the phase voltage at the lower level of the lightning arrester BL.

[0065] The number of parallel power supply modules MK1 is selected according to the actual load. Multiple parallel power supply modules MK1 are connected in parallel. Each parallel power supply module MK1 can provide the same voltage for the load and can flexibly distribute current according to the load demand.

[0066] When the load increases, by increasing the number of parallel power supply modules MK1, the total current output capacity can be correspondingly increased to meet the power supply requirements of the load.

[0067] The efficiency of the power supply module is usually related to the load rate. Within a certain load rate range, the power supply module can maintain a high efficiency. By selecting the number of parallel power supply modules MK1 that matches the actual load, each module can work in a state close to its optimal load rate.

[0068] For example, a parallel power supply module MK1 has the highest efficiency when the load rate is 60% - 80%. If the load demand is 80% of the module's rated power, one module can be configured; if the load demand increases to 160%, two modules are configured so that the load rate of each module remains around 80%. This can ensure that each module can work efficiently, thereby improving the energy utilization efficiency of the entire system.

[0069] Based on the parallel structure, when one or more parallel power supply modules MK1 fail (such as internal component damage, short circuit, etc.), the other normal modules can still work properly and supply power to the load.

[0070] In a parallel circuit, each branch is independent of each other. As long as one branch can conduct normally, it can provide current to the load.

[0071] For example, in a system with four parallel power supply modules MK1, even if one module fails, the remaining three modules can still jointly undertake the power supply task of the load. As long as the total output capacity of these three modules can meet the minimum demand of the load, the basic operation of the system can be maintained, thereby improving the reliability and redundancy of the system.

[0072] In this embodiment, 4 are used for illustration, and the parallel output is 220V DC voltage. An AC circuit breaker (i.e., the second circuit breaker QL2) is configured at the front end of each lithium iron phosphate intelligent parallel modular power supply to control the AC input of a single intelligent parallel modular power supply, and a DC circuit breaker (i.e., the third circuit breaker QL3) is configured at the rear end to control the DC output of a single intelligent parallel modular power supply. The first DC output positive terminal of the parallel power supply module MK1 is the 220V DC output positive terminal, and the first DC output negative terminal of the parallel power supply module MK1 is the 220V DC output negative terminal, thereby realizing the redundant design of the lithium iron phosphate intelligent parallel modular power supply, and improving the overload capacity, anti-interference ability and hot plug function.

[0073] In a preferred embodiment, a parallel modular power supply unit PMU is connected to a corresponding battery BAT through a communication interface CAN for CAN communication.

[0074] Specifically, the communication interface CAN is provided on the parallel power supply module MK1 in the parallel modular power supply unit PMU. Through the CAN communication protocol, data interaction can be carried out between the parallel power supply module MK1 and the battery BAT according to specific formats and rules. The power supply unit can send control instructions to the battery BAT, such as charging start, stop, adjustment of charging parameters, etc.; the battery BAT can then feedback its own status information to the power supply unit.

[0075] The two-way data interaction mechanism enables the power supply unit to dynamically adjust according to the actual situation of the battery BAT, realizing intelligent charging management and real-time monitoring.

[0076] CAN communication supports multi-node distributed control. In a parallel modular DC system, each power supply unit and the corresponding battery BAT can be regarded as an independent node. Through CAN communication, these nodes can cooperate with each other to jointly complete the operation tasks of the system, improving the flexibility and scalability of the system, and enabling the system to adapt to different application scenarios and scale requirements.

[0077] In a preferred embodiment, the positive terminal of the second DC output of the parallel power module MK1 is connected to the positive input terminal of the battery BAT, and the negative terminal of the second DC output of the parallel power module MK1 is connected to the negative input terminal of the battery BAT;

[0078] The negative output terminal of the (N - 1)th battery BAT is connected to the positive output terminal of the Nth battery BAT.

[0079] Specifically, the positive terminal of the second DC output of the parallel power module MK1 is the positive output terminal of 48V DC, and the negative terminal of the second DC output of the parallel power module MK1 is the negative output terminal of 48V DC. When the mains power is normal, the alternating current passes through the input EMI filter and lightning protection circuit and enters the APFC active power factor correction circuit, which is converted into +220V DC. One path of the DC is output as 220V through DC / DC buck, and the other path is bucked to 48V DC by DC / DC for intelligent charging of the lithium iron phosphate battery (battery BAT).

[0080] When the mains power is abnormal, the DC of the lithium iron phosphate battery passes through the battery input switch and enters the DC / DC boost circuit to convert the DC of the lithium iron phosphate battery into +220V DC for output.

[0081] When switching between the mains power supply mode and the battery power supply mode, the switching time is 0S. When the DC power supply fails, the main output is turned off through intelligent control for protection. The ARM embedded control system controls the entire DC power supply, including APFC, DC / DC isolation buck, current sharing, intelligent charging of the battery, online capacitance measurement, and AC / DC input switch control, etc.

[0082] ARM (Advanced RISC Machines) is a microprocessor with a reduced instruction set computer (RISC) architecture. The ARM embedded control system applies the ARM processor to an embedded system with specific functions.

[0083] In this parallel modular DC system of lithium iron phosphate batteries, as the core control unit, it comprehensively manages and controls the entire DC power supply.

[0084] APFC is a power electronics technology used to improve the power factor on the input side of the power supply and reduce the pollution of the power grid by harmonic currents.

[0085] The main power circuit of the parallel power supply module consists of an active PFC circuit (to improve the power factor and reduce current harmonics) and three DCDC conversion circuits with electrical isolation for both input and output (using resonant soft-switching technology to effectively improve the product efficiency).

[0086] The control system adopts a dual-CPU solution. The main CPU is responsible for driving and displaying the LCD built in the parallel modular power supply, communicating with the upper computer, current sharing among modules, and sampling and controlling the discharge DCDC conversion circuit; the slave CPU is responsible for sampling and controlling the PFC circuit, the rectifier DCDC conversion, and the charging DCDC conversion, and also communicates with the control system through CAN communication to achieve intelligent charging management of the lithium iron phosphate battery, master the SOH (state of health) of the lithium iron phosphate battery, charging management, and active and passive balancing, thereby effectively extending the service life of the lithium iron phosphate battery. Information interaction is achieved between the main and slave CPUs through internal communication.

[0087] In a preferred embodiment, referring to Figure 4 , the load part RL includes

[0088] Multiple electrical load modules EM. One electrical load module EM is connected between the positive power line +WC and the negative power line -WC through a DC output switch QF.

[0089] Specifically, the DC output switch QF is configured as a feed-out circuit breaker according to the size of each load to supply DC power for different devices.

[0090] The DC output switch QF usually has an overcurrent protection function. When the current passing through the switch exceeds a certain multiple of its rated current value, the thermal release or electromagnetic release inside the switch will quickly act, causing the switch to automatically disconnect.

[0091] The thermal release uses the heat generated when current passes through the bimetallic strip to deform the bimetallic strip, thereby triggering the tripping mechanism.

[0092] The electromagnetic release is based on the principle of electromagnetic induction. When the current is too large, it generates a large enough electromagnetic force to attract the armature, causing the tripping mechanism to act.

[0093] At the moment of short circuit, the short-circuit current will increase sharply, far exceeding the rated current of the DC output switch QF. At this time, the short-circuit protection device inside the switch will immediately detect this abnormal current and quickly trigger the tripping mechanism, causing the switch to disconnect the circuit within an extremely short time to protect the electrical module and the DC system from the damage of the short-circuit current. Short-circuit protection usually uses an electromagnetic release, whose action speed is very fast and can cut off the circuit within milliseconds.

[0094] When designing the DC output switch, the rated current, action characteristics and other parameters of the switch are reasonably selected according to the load characteristics and importance of different electrical modules EM, so that selective coordination can be achieved between each switch. When a fault occurs, the DC output switch closest to the fault point acts first to isolate the fault within the smallest range, while other normal switches will not misoperate, thus ensuring the power supply continuity and reliability of the system.

[0095] In a preferred embodiment, referring to Figure 3 , it further includes,

[0096] The fourth circuit breaker QL4, the first input end of the fourth circuit breaker QL4 is connected to the negative output end of the Nth battery BAT, and the second input end of the fourth circuit breaker QL4 is connected to the positive output end of the first battery BAT;

[0097] The first diode D1, the anode of the first diode D1 is connected to the second output end of the fourth circuit breaker QL4;

[0098] The second diode D2, the anode of the second diode D2 is connected to the anode of the first diode D1, and the cathode of the second diode D2 is connected to the cathode of the first diode D1;

[0099] The first fuse FL1, the first end of the first fuse FL1 is connected to the cathode of the first diode D1, and the second end of the first fuse FL1 is connected to the load part RL through a series connection of a second fuse FL2;

[0100] The first ammeter PA1, connected to the first fuse FL1;

[0101] The second ammeter PA2, connected to the second fuse FL2.

[0102] Specifically, in the total circuit of 4 lithium iron phosphate intelligent parallel modular power supplies, the second fuse FL2 is connected in series as the feed-out DC protection circuit, and the second ammeter PA2 is connected in series to detect the magnitude of the total feed-out current.

[0103] Four lithium iron phosphate battery packs are connected in series to a freewheeling device. The freewheeling isolation diode prevents the bus from charging the battery. When there is a short-circuit current in the feed-out loop, it provides a short-circuit current to the bus to ensure that the feed-out switch disconnects without affecting other feed-out loops (the intelligent parallel modular power supply has built-in output current limiting protection). The first fuse FL1 is used as a protection circuit, and the first ammeter PA1 is connected in series to detect the magnitude of the current in the freewheeling loop.

[0104] In a preferred embodiment, it further includes

[0105] A communication device RT, and the communication device RT is connected to the load part RL through a fifth circuit breaker QL5;

[0106] An insulation on-line detection device IMD, and the insulation on-line detection device IMD is connected to the load part RL through a sixth circuit breaker QL6. The insulation on-line detection device IMD is also connected in parallel with a first voltmeter PV1.

[0107] Specifically, in the bus circuit, one path is connected in parallel to control the power supply of the communication device RT (i.e., the communication gateway / optical-electric conversion device) through a DC circuit breaker (i.e., the fifth circuit breaker QL5), and the other path is connected in parallel with the first voltmeter PV1 to detect the output voltage and the insulation on-line detection device IMD to detect the real-time DC insulation.

[0108] In a preferred embodiment, it further includes a monitoring part MON, and the monitoring part MON includes

[0109] A current monitoring module IM, connected to the communication interface RS485 of the parallel modular power supply unit PMU, for obtaining the output current data of the parallel modular power supply unit PMU;

[0110] A voltage monitoring module VM, connected to the communication interface RS485 of the parallel modular power supply unit PMU, for obtaining the output voltage data of the parallel modular power supply unit PMU;

[0111] A power monitoring module PM, connected to the communication interface RS485 of the parallel modular power supply unit PMU, for obtaining the power data of the parallel modular power supply unit PMU;

[0112] An insulation monitoring module IMM, connected to the communication interface RS485 of the parallel modular power supply unit PMU, for monitoring the insulation state of the parallel modular power supply unit PMU;

[0113] A main monitoring module MMC, connected to the communication interface RS485 of the parallel modular power supply unit PMU, for collecting and analyzing the monitoring data of the current monitoring module IM, the voltage monitoring module VM, the power monitoring module PM, and the insulation monitoring module IMM.

[0114] Specifically, the current monitoring module IM, voltage monitoring module VM, power monitoring module PM, and insulation monitoring module IMM collect data by connecting to the communication interface RS485 of the parallel power module MK1 in the parallel modular power supply unit PMU. RS485 is an industrial standard serial communication interface, which has advantages such as strong anti-interference ability, long transmission distance, and support for multi-node communication. The monitoring module communicates with the parallel power module MK1 using the RS485 interface and obtains corresponding data according to a predetermined communication protocol (such as the Modbus protocol, etc.) to ensure the accuracy and stability of data transmission.

[0115] After receiving the data from each monitoring module, the main monitoring module MMC processes it using data analysis algorithms.

[0116] For example, power data is obtained by multiplying the current and voltage data and compared with the data from the power monitoring module for verification. At the same time, the main monitoring module MMC can use statistical analysis methods, such as trend analysis, threshold judgment, etc., to comprehensively analyze historical data and real-time data.

[0117] When the monitored data exceeds the normal range or shows an abnormal change trend, the main monitoring module MMC can make decisions according to the preset rules, such as sending an alarm signal, adjusting the system operation parameters, or starting standby equipment, etc., to ensure the normal operation of the system.

[0118] Each module of the monitoring unit MON cooperates with each other to form an organic whole. The current monitoring module IM, voltage monitoring module VM, and power monitoring module PM provide the basic operation parameters of the power module, the insulation monitoring module IMM ensures the safety of the system, and the main monitoring module MMC plays a central role in integrating and analyzing these scattered information. By working together through the RS485 communication interface, comprehensive monitoring and effective control of the parallel modular DC system are achieved.

[0119] In a preferred embodiment, the main monitoring module MMC is connected to a color touch screen CTS, and the color touch screen CTS is used to display the communication information between the main monitoring module MMC and the upper computer in real time.

[0120] Specifically, 4 intelligent parallel modular power supplies, ammeters (PA1, PA2), voltmeter (PV1), power meter, and insulation monitoring module IMM are all transmitted in parallel to the main monitoring module MMC through RS485 and the ModBus RTU protocol, and are displayed through the color touch screen CTS for communication with the upper computer.

[0121] The intelligent parallel modular DC system of lithium iron phosphate batteries designs a single lithium iron phosphate battery module and a matching parallel module as a parallel power supply component, which includes an AC / DC rectifier circuit and a battery charge and discharge management circuit module, integrated with one or more series-connected batteries BAT and circuits. The core is to directly boost the voltage of a single battery to the DC bus voltage, which can be compatible with various types of batteries BAT, and multiple component outputs are connected in parallel to form a parallel DC system. As long as one of them can work properly, the loop can be ensured to be unblocked, improving the reliability of the system. In addition, the intelligent parallel modular DC system can also realize the functions of online maintenance module and online maintenance battery, and can replace the battery and module without power interruption, further improving the flexibility and maintenance efficiency of the system.

[0122] The intelligent parallel modular power supply panel of lithium iron phosphate batteries consists of intelligent parallel modules, intelligent combined small DC circuit breakers, lithium iron phosphate battery modules (using ES51V100Ah standard modules), AC power distribution, etc.

[0123] The present invention has the advantages of high redundancy design, strong overload capacity and anti-interference ability. It can detect the health status of the battery BAT online, master the state of health (SOH) of the battery in real time, and improve the reliability of the system. The battery BAT can be periodically activated online and managed for charging, effectively extending the service life of the battery BAT. The parallel modular DC system of lithium iron phosphate batteries of the present invention adopts a high-frequency design, is small in size and light in weight, and has high reliability through special surge protection design. The working state is displayed through an LED, with clear display and simple operation. The intelligent communication interface RS485 can upload information such as the operation status of the power supply, voltage / current operation data, battery status and alarm signals in real time. The intelligent parallel charging module and the lithium iron phosphate battery use CAN communication, with stable communication and strong anti-interference ability, and online support for minimizing the replacement of lithium iron phosphate batteries.

[0124] The working temperature of the parallel modular DC system of lithium iron phosphate batteries of the present invention is -10°C to +50°C, the storage temperature is -40°C to +80°C, and the relative humidity is 10% to 90%.

[0125] The AC input voltage range of the present invention is 176Vac to 264Vac, the rated input voltage is 220Vac, the maximum input current is 8A, the input frequency range is 50Hz ± 2.5Hz, and the input power factor ≥ 0.98; the DC rated output voltage is 230Vdc, the output current range is 0A to 8A, the output voltage regulation accuracy ≤ ±0.5%, the output ripple coefficient is ±0.5%, the current sharing ≤ ±5%, the rated charging voltage is 54.4 ± 0.2Vdc, the soft start time is 3S to 8S, and all protection values can be set.

[0126] The above are only the preferred embodiments of the present invention, and do not limit the implementation manners and protection scope of the present invention. For those skilled in the art, it should be realized that any equivalent substitution and obvious changes made by using the specification and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A parallel modular DC system for lithium iron phosphate batteries, characterized in that including, a mains power access unit (MAI), the mains power access unit (MAI) providing an input power supply through three-phase four-wire; N parallel modular power units (PMU), the input ends of the parallel modular power units (PMU) being connected to the mains power access unit (MAI) for providing a DC power supply; N storage batteries (BAT), one storage battery (BAT) being correspondingly connected to one of the parallel modular power units (PMU), the storage battery (BAT) being charged through the parallel modular power unit (PMU); a load unit (RL), the load unit (RL) being connected to the output ends of the parallel modular power units (PMU).

2. The lithium iron phosphate battery parallel modular DC system according to claim 1, wherein The mains power access unit (MAI) includes: a first AC incoming line switch (HZ1), the three-phase input ends and the neutral input end of the first AC incoming line switch (HZ1) being connected to a power supply; a first circuit breaker (QL1), the first phase of the input end of the first circuit breaker (QL1) being connected to the first phase of the output end of the first AC incoming line switch (HZ1), the second phase of the input end of the first circuit breaker (QL1) being connected to the second phase of the output end of the first AC incoming line switch (HZ1), the third phase of the input end of the first circuit breaker (QL1) being connected to the third phase of the output end of the first AC incoming line switch (HZ1), and the neutral input end of the first circuit breaker (QL1) being connected to the neutral output end of the first AC incoming line switch (HZ1); a lightning arrester (BL), the first phase of the input end of the lightning arrester (BL) being connected to the first phase of the output end of the first circuit breaker (QL1), the second phase of the input end of the lightning arrester (BL) being connected to the second phase of the output end of the first circuit breaker (QL1), the third phase of the input end of the lightning arrester (BL) being connected to the third phase of the output end of the first circuit breaker (QL1), and the neutral input end of the lightning arrester (BL) being connected to the neutral output end of the first circuit breaker (QL1).

3. The lithium iron phosphate battery parallel modular DC system according to claim 1, characterized in that The internal circuit connection structures of the N parallel modular power units (PMU) are the same. A single parallel modular power unit (PMU) includes: a second circuit breaker (QL2), the first input end of the second circuit breaker (QL2) being connected to the first phase wire (A), and the second input end of the second circuit breaker (QL2) being connected to the neutral wire (N); a parallel power module (MK1), the first AC input end of the parallel power module (MK1) being connected to the first output end of the second circuit breaker (QL2), and the second AC input end of the parallel power module (MK1) being connected to the second output end of the second circuit breaker (QL2); a third circuit breaker (QL3), the first input end of the third circuit breaker (QL3) being connected to the first positive DC output end of the parallel power module (MK1), the second input end of the third circuit breaker (QL3) being connected to the first negative DC output end of the parallel power module (MK1), and the first output end and the second output end of the third circuit breaker (QL3) being connected to the load unit (RL).

4. The lithium iron phosphate battery parallel modular DC system according to claim 1, characterized in that, One of the parallel modular power units (PMUs) is connected to a corresponding one of the storage batteries (BATs) through a communication interface (CAN) for CAN communication.

5. The lithium iron phosphate battery parallel modular DC system according to claim 3, characterized in that, The positive terminal of the second DC output of the parallel power module (MK1) is connected to the positive input terminal of the storage battery (BAT), and the negative terminal of the second DC output of the parallel power module (MK1) is connected to the negative input terminal of the storage battery (BAT); The negative output terminal of the (N - 1)-th storage battery (BAT) is connected to the positive output terminal of the N-th storage battery (BAT).

6. The lithium iron phosphate battery parallel modular DC system according to claim 1, characterized in that, The load unit (RL) includes a plurality of power-consuming modules (EMs). One power-consuming module (EM) is connected between the positive power supply line (+WC) and the negative power supply line (-WC) through a DC output switch (QF).

7. The lithium iron phosphate battery parallel modular DC system according to claim 1, wherein It further includes a fourth circuit breaker (QL4). The first input terminal of the fourth circuit breaker (QL4) is connected to the negative output terminal of the N-th storage battery (BAT), and the second input terminal of the fourth circuit breaker (QL4) is connected to the positive output terminal of the first storage battery (BAT); a first diode (D1). The anode of the first diode (D1) is connected to the second output terminal of the fourth circuit breaker (QL4); a second diode (D2). The anode of the second diode (D2) is connected to the anode of the first diode (D1), and the cathode of the second diode (D2) is connected to the cathode of the first diode (D1); a first fuse (FL1). The first end of the first fuse (FL1) is connected to the cathode of the first diode (D1), and the second end of the first fuse (FL1) is connected to the load unit (RL) through a series connection of a second fuse (FL2); a first ammeter (PA1), connected to the first fuse (FL1); a second ammeter (PA2), connected to the second fuse (FL2).

8. The lithium iron phosphate battery parallel modular DC system according to claim 7, characterized in that It further includes a communication device (RT). The communication device (RT) is connected to the load unit (RL) through a fifth circuit breaker (QL5); an insulation on-line detection device (IMD). The insulation on-line detection device (IMD) is connected to the load unit (RL) through a sixth circuit breaker (QL6), and the insulation on-line detection device (IMD) is further connected in parallel with a first voltmeter (PV1).

9. The lithium iron phosphate battery parallel modular DC system according to claim 8, characterized in that, It further includes a monitoring unit (MON). The monitoring unit (MON) includes a current monitoring module (IM), connected to the communication interface (RS485) of the parallel modular power unit (PMU), for obtaining the output current data of the parallel modular power unit (PMU); a voltage monitoring module (VM), connected to the communication interface (RS485) of the parallel modular power unit (PMU), for obtaining the output voltage data of the parallel modular power unit (PMU); a power monitoring module (PM), connected to the communication interface (RS485) of the parallel modular power unit (PMU), for obtaining the power data of the parallel modular power unit (PMU); Insulation Monitoring Module (IMM), connected to the communication interface (RS485) of the Parallel Modular Power Unit (PMU), for monitoring the insulation status of the Parallel Modular Power Unit (PMU); Main Monitoring Module (MMC), connected to the communication interface (RS485) of the Parallel Modular Power Unit (PMU), for collecting and analyzing the monitoring data of the Current Monitoring Module (IM), the Voltage Monitoring Module (VM), the Power Monitoring Module (PM), and the Insulation Monitoring Module (IMM).

10. The lithium iron phosphate battery parallel modular DC system according to claim 9, characterized in that The Main Monitoring Module (MMC) is connected to a Color Touch Screen (CTS), and the Color Touch Screen (CTS) is used to display the communication information between the Main Monitoring Module (MMC) and the host computer in real time.

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