Author: Huang Sailin 1 Xiao Hua guest 2 Guo of 2 Huang Changshu child fine jade 3 Wujun beacon 2 Xie Hangxuan 3

Unit: 1. Limited company of power of Guangdong of national energy group; 2. Country can hill of broadcasting station of another name for Guangdong Province generates electricity limited company; 3. Electric power of southern electrified wire netting Inc. of science and technology

Cite: Huang Sailin, be like Hua Bin, huang Changshu. High-pressured cascade type store can the system is in fire store the application in combining frequency modulation and practice [J] . Store can science and technology, 2022, 11(11):3583-3593.

DOI: 10.19799/j.cnki.2095-4239.2022.0241

Summary " double carbon " below the target, the receives electrified wire netting in great quantities stability of new energy resources moves bring concussion. Fire store project of associated frequency modulation won extensive research and application in recent years as resource of high grade frequency modulation. According to Guangdong area fire store current situation of put into production of project of associated frequency modulation, this labour oppose basically applies Yu Huo at present store the low-pressure paralell connection that combines frequency modulation item and high-pressured cascade store can system two kinds of develop attack the structure undertakes an analysis, combinative frequency modulation assists service market policy, through attacking to different develop the power control precision below the structure, energy changes efficiency and noise to answer the project such as time is begun and network test studies, contrast analysed both function difference. The result makes clear use high-pressured cascade develop to attack of the structure store can the system has more superior power to control ability, rapidder noise to answer time, taller answer precision and smaller energy loss, conduce to raise temper store the function of integrated frequency modulation that combines frequency modulation item, promote the competition ability in frequency modulation market. Be based on high-pressured cascade store can systematic advantage, country can hill of broadcasting station of another name for Guangdong Province generates electricity limited company applies his according to oneself unit capacity and frequency modulation demand transform in unit flexibility in, designed country's at present biggest fire store project of associated frequency modulation, for follow-up fire store type of cascade of the high pressure in combining frequency modulation store can the research with systematic politic control provides support, also be other fire store the construction that combines frequency modulation item is offerred draw lessons from.

Keyword store can; High-pressured cascade; Low pressure is shunt-wound; Fire store associated frequency modulation; the net detects

"Double carbon " below the target, because the production of the sources of energy, consumption is mixed,use present new development trend, base of configuration of character of the power source structure that leaves power system in this trend, bear, electrified wire netting, technology and moving character will produce profound change, compose builds new-style power system to will be faced with safety of balance of electric power n, system stable, new energy resources is efficient use wait for a challenge. Because new energy resources generates electricity,have fluctuation and uncertainty, can affect the stability that electrified wire netting runs, to ensure safety of electrified wire netting stability moves, power system needs resource of more agile frequency modulation to promote oneself adjustment capability. Group of igneous electric machinery generates electricity importantly as our country carrier is assuming main frequency modulation to work. The automatic hair of group of igneous electric machinery is electronic-controlled make (Automatic Generation Control, AGC) answers time long, power climbs slope rate precision of slow, stable state is low, cannot satisfy current frequency modulation requirement. Electrochemistry store can the system is had adjust rate is fast, noisy should time weak point, adjust precision is advanced advantage, belong to high grade frequency modulation resource, what can offset performance of frequency modulation of group of igneous electric machinery effectively is insufficient. Graph 1 increase cell for some ammunition power plant store can curve of pursuit of systematic around AGC, increase store can after the system, series of igneous electric machinery can rise effectively generate electricity unit adjustment rate, shorten answer time, raise tone section precision, promote integrated frequency modulation property, cooperate electric power to attemper the frequency that the orgnaization improves electrified wire netting is fluctuant, alleviate resource of frequency modulation of electrified wire netting especially the problem of resource scarcity of high grade frequency modulation. To strengthen electrochemistry further store can power station safety manages, bureau of national energy resources was released " about strengthening electrochemistry store can the announcement that power station safety manages " , as a result of electrochemistry store can system and after the net, its power adjusts answer, the pattern that charges discharge and the influence of reliable moving generation that protect the metropolis such as the function to use electric device to aircrew and factory. In addition a lot of store can the project returns the phenomenon of load one's writing with fancy phrases with simple existence, bring about a lot of Chu Nengfu aids efficiency of energy of existence of frequency modulation project promotion of function of not tall, integrated frequency modulation is not apparent wait for a problem. Accordingly, for safeguard store can the security that system, aircrew and factory use electric bear moves, reduce production to run a risk, electrochemistry store frequency modulation system is in and the standard can be developed before the net comprehensive and the net detects have important sense.

Commercialize reform as electric power further development, a series of macroscopical policy are encouraged store can share auxiliary service market, in order to promote the flexibility of power system and attune section capability. Guangdong consumes big province as the sources of energy, its can be come from rate is inferior, to satisfy socioeconomy development and need of the people's livelihood, accelerate transition of low carbon of green of the sources of energy, the maritime wind report of large quantities of quantities is received, on the west report east send occupy increase than year after year, make the dimensions of Guangdong electrified wire netting and bear increasingly complex. Accordingly, guangdong electrified wire netting is put in pressing demand to resource of high grade frequency modulation, serve the market at starting Guangdong frequency modulation to assist in September 2018. Up to 2021 the end of the year, guangdong area already had 28 store investment of frequency modulation project moves or can try move, provided strong support to ensure stability of Guangdong area electrified wire netting. Among them 23 projects used low-pressure and shunt-wound compositive means, 5 projects used formula of set prescription of high-pressured cascade collect. The main distinction of two kinds of compositive means depends on its store can converter (Power Conversion System, PCS) is different the develop that cause attacks structural difference. As the ceaseless development of batteries industry and technology of electric power electron, right store can the research of converter is ceaseless also and thorough. But up to now, of course of two kinds of technologies in carrying to be being cast actually store can research of project function difference is less. Document [17-20] attacks to the develop of PCS the structure undertook study, comparative pictures attacks the structural influence to PCS function, according to actorring or actress defect attacks to develop the structure undertakes optimizing and confirm further through emulating, but lack what run data actually to prop up. Accordingly, pass and the analytic instrument that net function checks this kind of demonstration to change will study in joining movement actually, different develop attacks of the structure store can systematic performance has very fundamental economic value.

The fire inside area of this working union Guangdong store those who combine frequency modulation item develop a case, choose a few to use high-pressured cascade formula respectively store can system and low-pressure and shunt-wound type store can systematic fire store project of associated frequency modulation, the test method that demonstration of have the aid of changes, studied two kinds of develop attack of the structure store can project function difference, for follow-up fire store the considered to offer a case of a physically strong patient running a high fever or suffering from such disorders as stasis of blood to change research technique that combines frequency modulation item. Combine research result, in the fire with domestic the at present largest scale store project of associated frequency modulation used high-pressured cascade develop to attack structure, 60 MW/60 MWh of project total scope, use at improving a country can hill of broadcasting station of another name for Guangdong Province generates electricity limited company is integrated index of frequency modulation function, promote frequency modulation of area electrified wire netting the flexibility of resource, build security for sequel the fire with tall, superior performance store project of associated frequency modulation is offerred draw lessons from.

1 fire store develop of system of associated frequency modulation attacks structure

Current, guangdong area fire store the low pressure that combines frequency modulation is shunt-wound store can the PCS develop that what the system uses is only course type attacks structure, specific develop attacks the structure is shown 2 times like the graph. Store can the dc side that batteries receives DC/AC transformer repeatedly directly, repass step-up transformer turns into high pressure to input electrified wire netting. This kind of develop attacks the structure is simple, DC/AC transformer loss is small, control easily. But this structure is gone against store the amplification of can unit capacity. Although pass paralell connection enough much batteries bunch can increase store can systematic capacity, but in using a process, because batteries monomer exists consistency, charge other of equal difference of discharge electric current, moving environment, can bring about in the process that uses for a long time store can abhorrent sex delivers the system more highlight, cause battery loss of life then, store can the system can put electric energy to leave demote question. Jiashangzhi sheds the voltage of side batteries to restrict, communication side exports voltage to be controlled in 400 V commonly, at present although new 1500 V PCS can support dc side voltage to rise to 1500 V, corresponding communication side voltage is controlled in 700 V, but electrified wire netting of the high pressure in still needing to be received through step-up transformer ability, and the loss that step-up transformer of paralell connection much stage can add a system further and whole store can the cost of power station equipment and cover an area of an area. Accordingly, through paralell connection many transformer keep apart store can unit will expand store can systematic capacity also can cause systematic efficiency low reach stability issue. Besides, as a result of paralell connection many store can system, the mutual and harmonious meeting between shunt-wound much group PCS takes up partial system natural resources, shunt-wound PCS is more, of the system answer time to grow more.

In high-pressured cascade store can unit in, cascade store can the unit of every H bridge of PCS is mixed by group of a batteries to it shunt-wound filter wave capacitance and composition of circuit of H bridge inversion, m=2N+1(N of n of output phase voltage counts) for power transformation unit, output line voltage is 4N+1 n; As the addition of power transformation unit, can make and weaveform of net electric current is more flowing. Series connection of unit communication side regards many H bridge as cascade store can the one photograph of PCS, three-phase uses means of astral form wiring. relatively at low-pressure paralell connection, develop of high-pressured cascade system attacks the structure is relatively complex, if pursue,3 are shown. Low-pressure paralell connection and high-pressured cascade store can if systematic performance contrast expresses 1 show, high-pressured cascade store can the system can output 6 KV/10 KV directly, need not pass transformer, reduce systematic loss not only, improve efficiency, still decreased store can of the system cover an area of an area, reduced land to build construction cost, raised an unit to build the energy density of the area. In addition, attack in this kind of develop below the structure, store can system the shunt-wound condition that utmost ground decreases or can remove batteries to form a cluster, make each batteries become independent each other between bunch, decrease or eliminate batteries monomer and the circumfluent appearance that batteries forms a cluster, weakened store can the problem that consistency of the batteries in the system causes, increase the cycling life of batteries system, safe risk that reduced production to move. High-pressured cascade store can every three-phase is the system to control unit one group, store can the system does not need a basis shunt-wound store the instruction is answered again after the difference of can unit function undertakes harmony, shortened store can of the system answer time. The develop of high-pressured cascade attacks the structure can reduce switch loss in low-pressure dc side, improve systematic efficiency further; And the power cell place that the electronic component place of low-pressure side wants electric current and high-pressured side needs compression grade to all be reduced apparently, be helpful for increasing systematic stability.

2 different develop attack of the structure and net function

In aircrew devoted AGC mode falls, attemper to aircrew long-range terminal is unit (Remote Terminal Unit, RTU) sends statement of AGC frequency modulation, after RTU receives an instruction, transmit signal quickly control a system dispersedly to aircrew (Distributed Control System, DCS) , DCS controls aircrew to exert oneself to target cost, convey signal at the same time to store can control a system. Store can control a system according to frequency modulation aircrew the difference between real time bear and bear of AGC instruction target is worth, control store can unit give power volume to offset poor cost, feedback to RTU and DCS corresponding signal, RTU is received store can mix after the feedback signal of aircrew, integrated set and store can exert oneself circumstance go up to relevant data send attemper, complete cycle of a frequency modulation. Fire store the control logic develop that combines frequency modulation system attacks if knot composition of a picture pursues show 4 times.

According to southern region frequency modulation auxiliary service market trades regular, k of index of function of integrated frequency modulation is to be used at measuring to generate electricity the parameter that unit answers AGC to dictate integral performance is behaved, include to adjust rate K Ⅰ , noise is in season a K Ⅱ and adjust precision K Ⅲ 3 factor, the computational formula of K is:

Among them, adjust rate K Ⅰ points to generate electricity the rate that unit answers AGC to dictate; Answer time K Ⅱ to point to generate electricity the time delay time that unit answers AGC to dictate; Adjust precision K Ⅲ points to generate electricity the essence that unit answers AGC to dictate allows to spend; Ⅲ of Ⅱ of the Ⅰ of K of index of frequency modulation function that Ⅲ of Ⅱ of λ Ⅰ , λ , λ is correspondence, K, K is in the weight coefficient of K of index of integrated frequency modulation, current, λ Ⅰ is 0.5, λ Ⅱ and λ Ⅲ are 0.25. To the power plant, index of function of integrated frequency modulation is higher, the income that its attend frequency modulation to assist service market is higher. Accordingly store can systematic adjustment is rate, noisy should time and adjust precision is fire store the function index of the outbalance in combining frequency modulation.

PCS serves as the interface that dc transition makes between electrified wire netting and batteries, charging discharge and power control is its basiccest function, the responds power of time, have rendered great service control precision that charges discharge, control limits that does not have result power is the important parameter that measures PCS performance. Answer time to be able to affect K Ⅰ and K Ⅱ , answer precision to be able to affect K Ⅲ , affect fire thereby store the index of function of integrated frequency modulation of adjustment project. Without result power control ability can be behaved store can the flexibility that the system adjusts to power factor.

Energy changeover efficiency is an evaluation store can the main index of bad of actor of power station function, it was reflected store can systematic the sources of energy uses efficiency. Store can energy changeover efficiency of the system is taller, demonstrative system is jumped over in the loss of the energy in filling discharge process little. From fire store the economic benefits aspect that combines frequency modulation item is measured, higher energy changes efficiency to mean lower carry dimension cost.

The place on put together is narrated, in fire store in combining frequency modulation item, store can power control of the system, filling discharge to answer time and function of energy changeover efficiency is to measure fire store adjustment project store can of fruit of systematic market effect important technical index. Considering the consistency of test sample, with Guangdong provincial close of capacity of group of igneous electric machinery, store can 4 fire with similar dimensions store project of associated frequency modulation regards research as the object (specific parameter sees the project watch 2) , be opposite through devising experiment plan fire store of paralell connection of the low pressure in combining frequency modulation item and high-pressured cascade store can the system undertakes have rendered great service is mixed control without result power, fill discharge to answer function and energy to change efficiency comparative analysis, study different develop attacks of the structure store can system and net function.

3 tests program

Control of power of 3.1  have rendered great service checks

Will store can system and communal electrified wire netting are linked together undertake power of have rendered great service moves energy-saving force to rise fall test, according to GB/T 36548, 2018 " electrochemistry store can the system receives electrified wire netting to test a standard " , move is as follows:

(1) setting store can power of systematic have rendered great service is 0;

(2) chase power of class adjustment have rendered great service to come - 0.25PN, 0.25PN, - 0.5PN, 0.5PN, - 0.75PN, 0.75PN, - PN, PN, each power dots maintain at least 30 S, in store can system and the site measures sequential power, it is with average of power of have rendered great service of every 0.2 S a bit, record actual measurement data;

(3) with every time the have rendered great service of 15 S of computation of the 2nd 15 S after power of have rendered great service changes power average;

(4) computational measure (2) the control precision of power of each bits of have rendered great service, answer time and adjust time;

(5) setting store can power of systematic have rendered great service is PN;

(6) chase power of class adjustment have rendered great service to come - PN, 0.75PN, - 0.75PN, 0.5PN, - 0.5PN, 0.25PN, - 0.25PN, 0, each power dots maintain at least 30 S, in store can system and the site measures sequential power, it is with average of power of have rendered great service of every 0.2 S a bit, record actual measurement data;

(7) with every time the have rendered great service of 15 S of computation of the 2nd 15 S after power of have rendered great service changes power average;

(8) computational measure (6) the control precision of power of each bits of have rendered great service, answer time and adjust time.

3.2  checks without result power control

The respect is commanded in power, electrochemistry store can the system has 4 quadrant to control a function in a person operating from within in coordination with outside forces of moving limits of its convertor rated power, power of have rendered great service and should be without result power inside the shadow extent that the graph shows 5 times dynamic and adjustable. According to GB/T 36548, 2018 " electrochemistry store can the system receives electrified wire netting to test a standard " , test method is as follows:

Graph 5 Have rendered great service - without result power bag subsidiary channels in the human body through which vital energy pursues

Note: PN is electrochemistry store can systematic rated power, p and Q are electrochemistry respectively store can the power of have rendered great service that the system moves currently and without result power.

Will store can system and communal electrified wire netting are linked together, all parameter are moved to regular job requirement, undertake ability is filled modulatory without result power / discharge mode checks, the instruction when the test allots from EMS, move is as follows:

(1) setting store can the system is filled / power of discharge have rendered great service is PN;

(2) adjust store can the system moves in output the biggest sensibility does not have mode of result power job;

(3) in store can system and the site measures sequential power, record 30 S have rendered great service at least power and without result power, it is with average of power of every 0.2 S a bit, computation power of the have rendered great service inside the 2nd 15 S and the average that do not have result power;

(4) adjust respectively store can the system charges power of have rendered great service is 0.9PN, 0.8PN, 0.7PN, 0.6PN, 0.5PN, 0.4PN, 0.3PN, 0.2PN, 0.1PN, 0, repeat measure (2) ～ (3) ;

(5) adjust store can the system moves in output sex of the biggest look does not have mode of result power job, repeat measure (3) ～ (4) ;

(6) it is the abscissa with power of have rendered great service, it is ordinate without result power, scale store can systematic power includes plan of subsidiary channels in the human body through which vital energy.

3.3  fills discharge to answer function test

In checking a process, store can the system is reached by signal control the hour definition that fills discharge power to achieve 90% rated power first answers time to charge discharge, store can the system is reached by signal control the time definition that fills discharge power to achieve rated power first adjusts to charge discharge time.

In checking a process, store can the system is reached by signal control the hour definition that fills discharge power to achieve 90% rated power first answers time to charge discharge, store can the system is reached by signal control the time definition that fills discharge power to achieve rated power first adjusts to charge discharge time. Test method is as follows:

(1) discharge condition is filled to fall in rated power, record store can the hour T1 that the system gets control signal, record store can fill / the hour that puts electric power to achieve 90% rated power first, write down for T2, t2 subtractive T1 is namely fill / discharge answers time RTc, repeat 3 times, fill / discharge answers time to take the maximum in the result 3 times;

(2) discharge condition is filled to fall in rated power, record store can the hour T3 that the system gets control signal, record store can fill / the deviation of discharge power is maintained in rated power ± the initiative hour of 2% less than, write down for T4, t4 subtractive T3 is namely fill / ATc of discharge adjustment time, repeat 3 times, fill / discharge adjustment time takes the maximum in the result 3 times.

3.4  energy changes efficiency test

According to GB GB/T 36548, 2018 " electrochemistry store can the system receives electrified wire netting to test a standard " , store can efficiency of changeover of systematic rated power is to point to store the ratio that energy and energy of the input when the rated power in be the same as circular process charges can output when systematic rated power discharges. Test method is as follows:

(1) fall in stable moving condition, store can the system fills discharge condition to fall in rated power, with when rated power discharge ends a requirement to discharge, stopping to discharge, charge with rated power again to charge when ending a requirement, stop to charge. Minute book second charge in the process store can the energy Ec that the system charges and Wc of auxiliary specific power consumption;

(2) when ending a requirement to discharge with rated power discharge, stop to discharge. Minute book in second discharge process store can the energy En that the system discharges and Wn of auxiliary specific power consumption;

(3) repeat above measure 3 times, the record fills discharge energy Ec, En and Wc of auxiliary specific power consumption, Wn every time, according to the following formula computational energy changes efficiency η :

(1) power of have rendered great service checks as a result

Undertake to 4 projects power of have rendered great service controls a test, choose litre of power result to undertake an analysis, express the contrast of 6 through expressing 3 ～ , look on the whole, in have rendered great service control function checks an aspect, the control precision of project A, B all is worth it is respectively 0.51% and 0.62% , answer time all be worth mix for 0.578 S respectively 0.340 S, adjust time all is worth it is 0.625 S and 0.356 S respectively; The control precision with project D all is worth project C to be respectively 1.13% and 0.78% , answer time all be worth mix for 1.499 S respectively 0.642 S, adjust time all is worth it is 1.718 S and 0.926 S respectively; Can see, high-pressured cascade store can the system reachs control time to the control precision of power relatively excel low pressure is shunt-wound store can system. In low-pressure paralell connection store can in the system, with 5 MW store can unit for exemple, store can manage a system to need to allot the instruction after receiving an instruction store can unit, every store can unit through 8 PCS control batteries exerts oneself, finish relevant statement. And in high-pressured cascade store can in the system, store can unit need to pass control only a PCS achievable the control to batteries, because this shortened,answer time and adjust time.

(2) check without result power as a result

The have rendered great service according to project A and project C - without result power bag sth resembling a net pursues (graph 6) analysis, configured high-pressured cascade store can of project A of the system without result power control limits is more than configured low-pressure paralell connection store can project C of the system. Because low pressure is shunt-wound,this is store can systematic need receives electrified wire netting again through transformer step up, because transformer itself can be in,release very big without result, the meeting is right whole store can of the system cause very big effect without work control, and the system is in a lot of EMS to lack the compensation that does not have result influence to transformer to adjust without work control respect, bring about low-pressure and shunt-wound plan to suffer without work control ability on one hand be restricted, the control precision that does not have result power on the other hand is poorer. And the effect that high-pressured cascade plan does not suffer step up to change, can realize the 4 quadrantal control that do not have result power, no matter control limits or control precision,have an advantage more apparently.

(3) fill discharge to answer / adjust time tests as a result

Undertake to 4 projects time tests full discharging response reaching modulatory, the basis is expressed 7 can get, configured high-pressured cascade store can of project A of the system and project B fill discharge to answer time all apparent excel configured low-pressure paralell connection store can project C of the system and D. Because reach the demand of high capacity to achieve tall voltage,this is, low pressure is shunt-wound store can the system needs to use the series-parallel connection of parts of an apparatus such as more PCS, 4 this when control with 10 MW store can the project is exemple, high-pressured cascade system needs to control 2 5 MW PCS to exert oneself at the same time only, and low-pressure and shunt-wound plan needs to control 16 PCS to exert oneself at the same time, add whole system so control is complex degree, influence store can the system is filled discharge is answered and adjust rate, because of cascade of this high pressure store answer and can adjust of the system time is shorter.

(4) energy changeover efficiency checks as a result

The energy that undertakes to project A and project C 2 C fold fills discharge to fall changes efficiency test, the basis expresses 8 analysises, the energy changeover efficiency that project A fills discharge fold to fall in 2 C is 84.45% , 82.32% of C of prep above project. Because high-pressured cascade technology passes inversion,cascade hind receives electrified wire netting directly, did not pass a step-up transformer, reduced systematic loss thereby; Next, through series connection batteries bunch serves as the one photograph of PCS, can realize the independent control that every batteries forms a cluster, between implementation bunch balanced, reduce thereby whole store can the loss of systematic dc side; Plus every H bridge unit small carrier frequency reduced switch loss again, make configured high-pressured cascade store can the energy changeover efficiency of project A of the system is taller.

Pass above data analysis, in fire store in combining frequency modulation item, as a result of high-pressured cascade store can PCS amount of the system is less, lowered complex rate of the system, increased cooperative control capacity of the system, accordingly its answer time shorter, power pilot precision is taller; In addition, major EMS lacks the compensation that does not have result influence to transformer to adjust, caused low-pressure parallel connection store can of the system control capacity without result power poorer, jiashangsheng presses the loss of transformer, make high-pressured cascade store can the system has an advantage more in respect of energy changeover efficiency.

Type of cascade of 5 high pressure store can the system is in country can the applied practice of the group

Current, accompany southern region frequency modulation to assist service market to mature gradually, the igneous power plant of Guangdong area already finished fire gradually store those who combine frequency modulation transform. Assist the ability of frequency modulation to promote set, carry the frequency modulation resource of high quality for electrified wire netting, country can hill of broadcasting station of another name for Guangdong Province generates electricity limited company spreads out flexibility to oneself aircrew (auxiliary frequency modulation) technical reformation. Stability runs demand of frequency modulation of electrified wire netting of the capacity that is based on group of igneous electric machinery, place and the safety that ensure aircrew, this project deployed the batteries system of 60 MW/60 MWh in all. Considering the batteries system that promotes aircrew K of index of function of integrated frequency modulation and high capacity, to reduce energy loss and reduce store the safe risk that can unit paralell connection causes batteries system consistency, the develop that chose high-pressured cascade PCS attacks structure, designed country's biggest fire store project of associated frequency modulation, project in April 2022 the portion begins to build, the plan comes true to join movement formally by 2022.

The project plans to be in 1, 2 aircrew and 6, factory of 7 aircrew 6 KV uses electric system to add the phosphoric acid that assembles a 25 MW/25 MWh and 35 MW/35 MWh respectively Chu Nengfu of Tie Li electrochemistry helps frequency modulation system, receive respectively 1, 2, 6, generatrix of 7 aircrew 6 KV, 1, 2 aircrew store develop of can unit system attacks the structure is shown 7 times like the graph. Store can batteries system adds up to cascade of 12 5 MW/5 MWh store can unit, store can the develop that systematic unit adopts cascade H bridge attacks structure, circuit uses astral form connection, every photograph is comprised by series connection of 13 chain link; Every chain link is comprised by unit of a power and ark of a batteries, if pursue,8 are shown. The rated volts d.c. of every batteries ark is 716.8 V, the capacity is 129.024 KWh, every batteries ark is comprised by series connection of box of batteries of 14 51.2 V/9.216 KWh. Course of this project technology has the following characteristic:

(1) this project uses develop of cascade H bridge to attack structural inverter, circuit uses astral form connection, every photograph is comprised by series connection of 13 chain link; Every chain link is comprised by unit of a power and ark of a batteries, besides, the PCS that this project deploys has bunch active and balanced function, reduce deviation of the SOC between bunch, improve battery life;

(2) this project is used without means of batteries bunch paralell connection, join with electrified wire netting directly, solve not only store can the cask that large-scale series-parallel connection causes cell is short board effect, still enhanced systematic security;

(3) to reduce safe risk further, this project still was used " 4 class " safe fire extinguishing system, efficient and implementation on the safe side, accurate fire control early-warning and fire are restrained.

Pass afore-mentioned characteristics, in the project construction and later period move in, combinative unit is real frequency modulation circumstance, will right the control strategy of converter of high-pressured cascade power and " 4 class " fire extinguishing system is right fire store the safeguard that combines security of frequency modulation project two respects begin thorough research, for other fire store adjustment project provides technical experience.

6 conclusion

(1) Guangdong area fire store in combining frequency modulation item store can the system is main the develop of only course PCS with low-pressure paralell connection attacks structure and develop of high-pressured cascade PCS attack the structure is given priority to. This job is passed and net function test joins movement to Guangdong area medium store can the project has a test, the method that changes with a case of a physically strong patient running a high fever or suffering from such disorders as stasis of blood studied different develop attacks of the structure store can the system is in fire store the function difference in combining frequency modulation item: The PCS amount that because high-pressured cascade develop attacks,structural place needs is less, the system is complex rate is low, because prep above of ability of this cooperative control is low-pressure shunt-wound develop attacks of the structure store can system, answer time shorter, answer precision taller; And high-pressured cascade system need not pass a step-up transformer, reduced loss, eliminate a step-up transformer to be opposite the influence that does not have result power, the energy that improved a system changes efficiency, also improved a system to having ability of result power pilot.

(2) country can hill of broadcasting station of another name for Guangdong Province generates electricity limited company is based on oneself aircrew circumstance and frequency modulation demand, specific aim ground chose high-pressured cascade store can system, designed home at present the biggest fire store project of associated frequency modulation. This project matched system of battery of lithium of iron of phosphoric acid of 60 MW/60 MWh, be united in wedlock " 4 class " fire extinguishing system, so that sequel begins high-pressured cascade PCS to dominate strategy and the research with fire control politic safety, for other fire store adjustment project provides technical experience.

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