A kind of energy accumulation current converter and battery energy storage system thereofTechnical field
The present invention relates to a kind of energy accumulation current converter and battery energy storage system thereof.
Background technology
Distributed generation technology relies on it can improve system power supply reliability, reduce terminal use's expense, reduce line loss, improve the extensive concern that the advantages such as the quality of power supply have obtained the whole society.Distributed power generation mainly comprises all kinds of renewable energy power generations (wind energy, solar energy, biomass energy etc.), and the feature of its clean environment firendly has met the requirement of low-carbon economy development.
Yet, independent distributed power generation access electrical network is because the features such as intermittence, fluctuation, randomness of himself have been brought certain impact to electrical network, trend, failure mechanism characteristic that not only causes electrical network etc. is more complicated, and because its Ability of Resisting Disturbance is poor, abandon light, to abandon wind phenomenon very serious, cause distributed power generation annual utilization hours to decline, affected the economy of distributed power generation investment.
Microgrid is to collect by distributed power source, energy conversion apparatus, load, monitoring and protective device etc. the small electrical system forming.Microgrid both can with the parallel running of large-scale power net, also can be independently provide electricity needs for locality load.Microgrid both can be incorporated into the power networks, and can, from network operation, greatly improve the power supply reliability of load side again.By microgrid, access electrical network, can realize stabilizing of the inner fluctuation of microgrid dissolves, reduce the impact of distributed power source access electrical network, optimum organization by distributed power source and distributed energy storage moves in addition, can improve the ability of dissolving of distributed power source, so microgrid has become one of better form making full use of distributed power generation.
The regenerative resource that wind-force, photovoltaic generation is representative of take has intermittence, randomness and the feature such as uncertain, brings stern challenge to the safe and reliable operation of microgrid.Energy-storage system (Energy Storage System, ESS) relies on it can fill the operation characteristic that can put, can effectively overcome the fluctuation of renewable energy system.ESS controls different two classes that are broadly divided into of target from renewable energy system matching model by it: 1) coordinate the level and smooth output pulsation of regenerative resource: comprise short-term and Long-term Fluctuation; 2) batch (-type) regenerative resource is changed into and can dispatch the energy, realize peak load shifting, plan generating etc.
According to ESS, discharge and recharge time resolution characteristics, ESS can be divided into power-type ESS and energy type ESS.The former take ultracapacitor, flywheel ESS is representative, and the feature such as have response fast (fast charging and discharging), the life-span is long, capacity is little is applicable to the fluctuation of compensation short-time rating; The latter be take storage battery as representative, has the features such as capacity is large, low-response (comparing power-type ESS), power fluctuation while being applicable to compensation length.When level and smooth main wave component is low frequency component, can choose energy type ESS; When main wave component is high fdrequency component, generally can choose power-type ESS; When the existing low frequency component of main wave component, while having high fdrequency component again, must choose 2 kinds of ESS simultaneously and form and mix ESS patterns.
Therefore, for this micro-grid system of having gathered multiple renewable energy sources, a set of battery energy storage system need to be installed, by energy accumulation current converter PCS, be incorporated to storage and the release that microgrid carries out electric energy, PCS is a kind of important component part of battery energy storage system, for realizing the bidirectional energy transmission between battery energy storage system dc-battery and AC network, at present, PCS is at solar energy, wind energy distributed generation technology always has more application, yet the power fluctuation due to the micro-grid system larger high frequency of existence or low frequency, the ability of existing PCS device filtering high frequency ripple and low-frequency ripple is poor, the reliability of applying in micro-electrical network is poor.
Summary of the invention
The object of this invention is to provide a kind of energy accumulation current converter and battery energy storage system thereof, the AC of this energy accumulation current converter is provided with LCL mode filter, the high-frequency harmonic that electrical network can be produced and the high-frequency harmonic filtering of converter switches frequency, DC side is provided with CL filter, current/voltage harmonic wave that can filtering DC side radio-frequency component, suppress high frequency ripple, in DC side and AC, be provided with electromagnetic interface filter simultaneously, the further humorous wave interference of filtering, improve microgrid reliability of operation, solved power fluctuation in microgrid, the poor problem of microgrid operational reliability.
For achieving the above object, the solution of the present invention is: a kind of energy accumulation current converter, comprise AC/DC module, main contactor, AC pre-charge circuit, main circuit breaker, DC side pre-charge circuit and DC side circuit breaker, the AC of described AC/DC module connects one end of described main contactor, the other end of described main contactor connects one end of described main circuit breaker, the other end access electrical network of described main circuit breaker, described AC pre-charge circuit is connected in parallel on the two ends of main contactor, the DC side of described AC/DC module connects one end of described DC side circuit breaker, the other end of described DC side circuit breaker connects battery pack, described DC side pre-charge circuit is connected in parallel on the two ends of DC side circuit breaker, this energy accumulation current converter also comprises the LCL filter that is arranged on AC/DC module AC and exchanges electromagnetic interface filter, and the CL filter and the direct current electromagnetic interface filter that are arranged on AC/DC module DC side, one end of described CL filter connects the DC side of AC/DC module, the CL filter other end connects a side of direct current electromagnetic interface filter, the opposite side of described electromagnetic interface filter connects DC side circuit breaker, one end of described LCL filter connects the AC of AC/DC module, and the other end of LCL filter connects a side that exchanges electromagnetic interface filter by described main contactor, and the opposite side of described electromagnetic interface filter connects described main circuit breaker.
The AC of described AC/DC module is also connected with communication lightning-protection device, and described communication lightning-protection device is connected in parallel between described main circuit breaker and electrical network.
Described AC/DC module is a three-phase bridge rectification circuit.
The present invention also provides a kind of energy-storage system of applying above-mentioned energy accumulation current converter, comprise battery pack, battery management system, energy accumulation current converter, energy storage controller, energy storage monitor system, microgrid tuning controller and isolating transformer, described battery management system and battery pack communication connection, the AC of described energy accumulation current converter accesses microgrid by isolating transformer, the DC side of described energy accumulation current converter connects battery pack, the communication port of described energy accumulation current converter and the communication connection of energy storage controller, described energy storage controller communicates to connect by CAN bus and battery management system, described energy storage monitor system communicates to connect by RS485 interface and energy storage controller, described microgrid tuning controller communicates to connect by Ethernet and energy storage controller, described energy accumulation current converter comprises AC/DC module, main contactor, AC pre-charge circuit, main circuit breaker, DC side pre-charge circuit and DC side circuit breaker, the AC of described AC/DC module connects one end of described main contactor, the other end of described main contactor connects one end of described main circuit breaker, the other end access electrical network of described main circuit breaker, described AC pre-charge circuit is connected in parallel on the two ends of main contactor, the DC side of described AC/DC module connects one end of described DC side circuit breaker, the other end of described DC side circuit breaker connects battery pack, described DC side pre-charge circuit is connected in parallel on the two ends of DC side circuit breaker, this energy accumulation current converter also comprises the LCL filter that is arranged on AC/DC module AC and exchanges electromagnetic interface filter, and the CL filter and the direct current electromagnetic interface filter that are arranged on AC/DC module DC side, one end of described CL filter connects the DC side of AC/DC module, the CL filter other end connects a side of direct current electromagnetic interface filter, the opposite side of described electromagnetic interface filter connects DC side circuit breaker, one end of described LCL filter connects the AC of AC/DC module, and the other end of LCL filter connects a side that exchanges electromagnetic interface filter by described main contactor, and the opposite side of described electromagnetic interface filter connects described main circuit breaker.
The AC of described AC/DC module is also connected with communication lightning-protection device, and described communication lightning-protection device is connected in parallel between described main circuit breaker and electrical network.
Described AC/DC module is a three-phase bridge rectification circuit.
The beneficial effect that the present invention reaches: the present invention is provided with LCL mode filter at the AC of energy accumulation current converter, the high-frequency harmonic that electrical network can be produced and the high-frequency harmonic filtering of converter switches frequency, DC side is provided with CL filter, current/voltage harmonic wave that can filtering DC side radio-frequency component, suppress high frequency ripple, in DC side and AC, be provided with electromagnetic interface filter, further the humorous wave interference of filtering simultaneously.Meet the requirement of the anti-electrical network interference of current transformer of GB10236-88 regulation, to injecting the harmonic wave of micro-electrical network, be effectively controlled, meet relevant national standard.Meet the requirement of the anti-micro-electrical network interference of current transformer of GB10236-88 regulation, solved the power fluctuation problem of micro-electrical network, improved the reliability of micro-operation of power networks.
Accompanying drawing explanation
Fig. 1 is the structure principle chart of energy accumulation current converter of the present invention;
Fig. 2 is the structure principle chart of energy-storage system of the present invention.
Embodiment
Below in conjunction with accompanying drawing, the present invention is further detailed explanation.
Energy accumulation current converter embodiment of the present invention:
Energy accumulation current converter of the present invention comprises AC/DC module, main contactor, AC pre-charge circuit, main circuit breaker, DC side pre-charge circuit and DC side circuit breaker, the AC of described AC/DC module connects one end of described main contactor, the other end of described main contactor connects one end of described main circuit breaker, the other end access electrical network of described main circuit breaker, described AC pre-charge circuit is connected in parallel on the two ends of main contactor, the DC side of described AC/DC module connects one end of described DC side circuit breaker, the other end of described DC side circuit breaker connects battery pack, described DC side pre-charge circuit is connected in parallel on the two ends of DC side circuit breaker, this energy accumulation current converter also comprises the LCL filter that is arranged on AC/DC module AC and exchanges electromagnetic interface filter, and the CL filter and the direct current electromagnetic interface filter that are arranged on AC/DC module DC side, one end of described CL filter connects the DC side of AC/DC module, the CL filter other end connects a side of direct current electromagnetic interface filter, the opposite side of described electromagnetic interface filter connects DC side circuit breaker, one end of described LCL filter connects the AC of AC/DC module, and the other end of LCL filter connects a side that exchanges electromagnetic interface filter by described main contactor, and the opposite side of described electromagnetic interface filter connects described main circuit breaker.
As shown in Figure 1, in the present embodiment, AC/DC module is a three-phase bridge rectification circuit; The AC of AC/DC module is also connected with communication lightning-protection device, communication lightning-protection device be connected in parallel on and main circuit breaker between electrical network; AC pre-charge circuit is composed in series by first resistance and first contactor; Direct current pre-charge circuit is composed in series by second resistance and second contactor.
This energy accumulation current converter is a two way convertor, the DC side access battery pack of this two way convertor, AC accesses micro-electrical network, can realize energy two-way exchange between battery pack and micro-electrical network, can be operated in batteries charging pattern and battery pack power feedback grid pattern, when batteries charging, the alternating current that electrical network produces, through the rectifying conversion of AC/DC module, is converted to direct current by alternating current and flows to battery pack; When battery pack power has residue, the electric energy storing in battery pack, through the rectifying conversion of AC/DC module, the direct current that battery pack is sent is transformed to alternating current, flows to electrical network, realizes the two-way flow of electric energy between battery pack and electrical network;
The present embodiment is provided with LCL mode filter at the AC of energy accumulation current converter, the high-frequency harmonic that electrical network can be produced and the high-frequency harmonic filtering of converter switches frequency, DC side is provided with CL filter, current/voltage harmonic wave that can filtering DC side radio-frequency component, suppress high frequency ripple, in DC side and AC, be provided with electromagnetic interface filter, further the humorous wave interference of filtering simultaneously.Meet the requirement of the anti-electrical network interference of current transformer of GB10236-88 regulation, to injecting the harmonic wave of electrical network, be effectively controlled, meet relevant national standard.
Energy-storage system of the present invention is embodiment:
As Fig. 2, energy-storage system of the present invention comprises battery pack, battery management system, energy accumulation current converter, energy storage controller, energy storage monitor system, microgrid tuning controller and isolating transformer, described battery management system and battery pack communication connection, the AC of described energy accumulation current converter accesses microgrid by isolating transformer, the DC side of described energy accumulation current converter connects battery pack, the communication port of described energy accumulation current converter and the communication connection of energy storage controller, described energy storage controller communicates to connect by CAN bus and battery management system, described energy storage monitor system communicates to connect by RS485 interface and energy storage controller, described microgrid tuning controller communicates to connect by Ethernet and energy storage controller, described energy accumulation current converter comprises AC/DC module, main contactor, AC pre-charge circuit, main circuit breaker, DC side pre-charge circuit and DC side circuit breaker, the AC of described AC/DC module connects one end of described main contactor, the other end of described main contactor connects one end of described main circuit breaker, the other end access electrical network of described main circuit breaker, described AC pre-charge circuit is connected in parallel on the two ends of main contactor, the DC side of described AC/DC module connects one end of described DC side circuit breaker, the other end of described DC side circuit breaker connects battery pack, described DC side pre-charge circuit is connected in parallel on the two ends of DC side circuit breaker, this energy accumulation current converter also comprises the LCL filter that is arranged on AC/DC module AC and exchanges electromagnetic interface filter, and the CL filter and the direct current electromagnetic interface filter that are arranged on AC/DC module DC side, one end of described CL filter connects the DC side of AC/DC module, the CL filter other end connects a side of direct current electromagnetic interface filter, the opposite side of described electromagnetic interface filter connects DC side circuit breaker, one end of described LCL filter connects the AC of AC/DC module, and the other end of LCL filter connects a side that exchanges electromagnetic interface filter by described main contactor, and the opposite side of described electromagnetic interface filter connects described main circuit breaker.
As shown in Figure 1, in the present embodiment, AC/DC module is a three-phase bridge rectification circuit; Battery pack is lithium ion battery; The AC of AC/DC module is also connected with communication lightning-protection device, and communication lightning-protection device is connected in parallel on main circuit breaker between electrical network; AC pre-charge circuit is by being composed in series by first resistance and first contactor; Direct current pre-charge circuit is comprised of second resistance and second contactor.
Battery management system gathers the service data information of battery pack, energy storage controller is communicated by letter with battery BMS by CAN bus, energy accumulation current converter gathers the service data information of battery pack by energy storage controller, microgrid tuning controller is by Ethernet and energy storage controller switching system information, battery information and control command, realization is controlled system coordination, energy storage monitor system, by RS485 interface and energy storage controller exchange message, is realized the monitoring on the spot to energy-storage system.
The present embodiment energy-storage system adopts the operational mode of module parallel running, centralized monitor management.Energy storage monitor system carries out interface by communication interface and battery pack and PCS, can realize functions such as " remote measurement, remote signalling, remote control, remote regulating ".This energy-storage system can be realized the two-way exchange of energy between battery and electrical network, can be operated in charge in batteries pattern and storage battery energy feedback grid pattern, and specific works process coexists mutually with the embodiment of energy accumulation current converter, does not repeat them here; The Power Exchange of each Battery pack coordinate to be controlled by energy storage monitor system, supports output-constant operation, wherein changes in cell process for any one group, can automatically increase the Power Exchange of other several groups, maintains basicly stable with systems exchange power; Can adopt the control modes such as long-range, local, equipment has stores mode of operation function at times, and when breaking down with background management system, equipment can carry out work according to the mode of operation at times of this locality storage.
The present invention is provided with LCL mode filter at the AC of energy accumulation current converter, the high-frequency harmonic that electrical network can be produced and the high-frequency harmonic filtering of converter switches frequency, DC side is provided with CL filter, current/voltage harmonic wave that can filtering DC side radio-frequency component, suppress high frequency ripple, in DC side and AC, be provided with electromagnetic interface filter, further the humorous wave interference of filtering simultaneously.Meet the requirement of the anti-electrical network interference of current transformer of GB10236-88 regulation, to injecting the harmonic wave of electrical network, be effectively controlled, meet relevant national standard.Meet the requirement of the anti-electrical network interference of current transformer of GB10236-88 regulation.