Grid type light stores up and the microgrid control system of generating setTechnical field
The present invention relates to a kind of storage of grid type light and the microgrid control system of generating set, belongs to electricity generation system technology neckDomain.
Background technology
The high speed development of Chinese national economy, has benefited from energy industry to a certain extent, China be production of energy state andCountry of consumption, energy supply sustainable growth, important guarantee is provided for economic development.Clean energy resource is greatly developed opposite to reduceThe ratio of fossil energy and the degree of dependence to the import energy in China's energy demand, while be conducive to optimize matching somebody with somebody for national energyStructure is put, the economic benefit of comprehensive utilization of energy is improved and reduces problem of environmental pollution, reduce the financial cost of pollution administration.
From the point of view of regenerative resource currently on the market and clean energy resource, the single energy cannot fully meet all need to for marketAsk, such as：Photovoltaic generation power fluctuating change is larger, and rely on weather, can not 24 it is small when persistently generate electricity, conventional power generation usage unit phaseIt is higher to alternating current and photovoltaic generation operating cost, and pollute environment.The cost of investment of energy-storage system is excessive, and itself can not send outThese distributed power generations are accessed bulk power grid, impact can be brought to bulk power grid, influences bulk power grid quality by electricity.
The content of the invention
It is an object of the invention to overcome drawbacks described above existing in the prior art, it is proposed that one kind realize distributed power generation withAlternating current seamless switching, it is ensured that user's uninterrupted power supply, and ensure the frequency of system and the storage of grid type light and power generation of voltage stabilizationThe microgrid control system of unit.
The present invention is realized using following technical solution：
A kind of grid type light storage and the microgrid control system of generating set, including power distribution network and micro-capacitance sensor, the power distribution networkIt is connected between micro-capacitance sensor and is switched fast switch, the micro-capacitance sensor includes generator, photovoltaic generation group, storage battery, direct current and bearsCarry and AC load, photovoltaic generation group are connected by photovoltaic DC-to-AC converter with ac bus, storage battery is by energy storage controller with handing overBusbar connection is flowed, AC load is directly connected with ac bus, and DC load is connected by AC/DC converters with ac bus,Data collector is respectively connected with each branch, further includes host computer, the host computer is connected by communication counter with ac bus,The communication counter and each data collector and switch connection is switched fast, host computer is by data collector collection microgrid with matching somebody with somebodyThe voltage of point of common coupling between power grid realizes grid-connected/off-network switching, by gathering photovoltaic power generation capacity, load realtime powerWith energy storage device capacity, so as to fulfill corresponding control model under off-network.
Further, the energy storage controller uses three-phase half-bridge voltage source type PWM rectifier, and direct current lateral load is lithiumBattery energy storage unit, exchange side use LCL filter.
Further, environment detector is further included, environment detector is connected with communication counter, real-time report light radiation amount,Host computer contrasts real-time lighting amount of radiation and photovoltaic system actual power generation, sees whether photovoltaic efficiency is normal at oneIn the range of, judge whether photovoltaic module is excessively dirty or damages, so as to maintenance personal's timely processing.
Further, the photovoltaic module uses crystal silicon photovoltaic battery or film photovoltaic cell.
Further, the switch that is switched fast uses solid-state switch.
The beneficial effects of the invention are as follows：
(1) seamless switching is realized, it is ensured that user's uninterrupted power supply, when alternating current plan or unplanned outage, system will be verticalI.e. cut-out is contacted with alternating current, switchs to isolated network pattern by grid-connect mode, independent operating is user's continued power, and seamless switching is adoptedWith high-power solid-state switch, ensure that the power of important load and distributed generation resource being capable of quick flat in a short period of time after off-networkWeighing apparatus.Energy storage undertakes system frequency and the stabilization of voltage as voltage source after micro-capacitance sensor off-network.
(2) generating set is added as common power supply, is greatly reduced the installed capacity of storage battery, is reduced the initial stage of projectCost of investment.
Brief description of the drawings
Fig. 1 is the structure diagram of the present invention.
Fig. 2 is the energy storage controller circuitry schematic diagram of the present invention.
Fig. 3 is the control principle drawing of the energy storage controller of the present invention.
Embodiment
The invention will be further described below in conjunction with the accompanying drawings.
As shown in Figure 1, the microgrid control system of a kind of grid type light storage and generating set, including power distribution network and micro-capacitance sensor,It is connected between the power distribution network and micro-capacitance sensor and is switched fast switch, the micro-capacitance sensor includes generator, photovoltaic generation group, electric power storagePond, DC load and AC load, photovoltaic generation group are connected by photovoltaic DC-to-AC converter with ac bus, and storage battery passes through energy storage controlDevice processed is connected with ac bus, and AC load is directly connected with ac bus, and DC load is by AC/DC converters with exchanging motherLine connects, and is respectively connected with data collector on each branch, further includes host computer, the host computer is by communication counter with exchanging motherLine connects, and the communication counter is connected with each data collector, can also use and be wirelessly transferred, the communication counter is adopted with each dataStorage passes through the point of common coupling between data collector collection microgrid and power distribution network with switch connection, host computer is switched fastVoltage realizes grid-connected/off-network switching, by gathering photovoltaic power generation capacity, load realtime power and energy storage device capacity, so that realCorresponding control model under existing off-network.Environment detector is further included, shines amount of radiation, environment detector and communication counter for detection lightConnection, real-time report light radiation amount, host computer contrast real-time lighting amount of radiation and photovoltaic system actual power generation, see lightGenerating efficiency is lied prostrate whether in a normal scope, judges whether photovoltaic module is excessively dirty or damages, so that maintenance personal is timelyProcessing.
As shown in Fig. 2, the energy storage controller uses three-phase half-bridge voltage source type PWM rectifier, direct current lateral load isLithium battery energy storage battery unit, exchange side use LCL filter, and the photovoltaic module is using crystal silicon photovoltaic battery or film photovoltaic electricityPond, the switch that is switched fast use solid-state switch.
The present invention operation principle be：
As shown in figure 3, when power distribution network malfunctioning systems are in grid-connected, energy storage controller uses three close-loop control, including simultaneouslyNet inductive current ring, filter capacitor Voltage loop and filter inductance electric current loop, grid-connected inductive current ring realize energy-storage units output workThe adjusting of rate, filter capacitor Voltage loop and filter inductance electric current loop realize accurate, the dynamic control of three-phase voltage current, power distribution networkWhen breaking down, host computer detects the Voltage Drop of the point of common coupling between microgrid and power distribution network by data collector,When dropping into certain threshold value, host computer sends instruction, and cut-out is switched fast switch, and system switchs to isolated network pattern by grid-connect mode,Energy storage controller switches to voltage control from current control, and busbar voltage is adjusted, i.e., is changed into two ring controls from three close-loop controlMake, the pwm signal of energy storage controller, the electricity of output are produced after filtered capacitance voltage ring, filter inductance electric current loop double -loop controlPressure amplitude value and phase and the amplitude and phase of voltage at off-grid eve point of common coupling are consistent, at this time from photovoltaic to loadPower supply, generating set assist power supply, and whole handoff procedure can be completed in 10ms.
After being switched to off-network state, communication counter by data collector gather photovoltaic power generation capacity, load realtime power andEnergy storage device capacity is simultaneously uploaded to host computer, and host computer judges each energy value, if photovoltaic power generation capacity, load are in real timePower swing, and beyond the compensation ability of energy-storage system, causes falling for system frequency and voltage, exceedes definite value when fallingWhen system enter " low-frequency low-voltage load shedding " pattern, excision is inessential or secondary important load, to ensure that system occurs without collapse of frequencyAnd collapse of voltage；If photovoltaic power generation capacity, load realtime power fluctuation cause system frequency beyond the compensation ability of energy-storage systemWith the rising of voltage, when being increased beyond definite value, system enters " crush-cutting machine is crossed in overfrequency " pattern, and restricted part photovoltaic is sent out at this timeElectricity, to ensure that system frequency and voltage return to normal range (NR)；When photovoltaic power generation capacity is more than current loads, system entersThe power supply of " the larger control of distributed power generation " pattern, at this time recovered part cutting load；When photovoltaic power generation capacity is much larger than loadWhen, all loads do not power off at this time, and energy storage is also filled with, and system enters " the excessive control of distributed power generation " pattern, at this time photovoltaicPower generation is exited, and is powered by energy storage device, energy storage for power supply to a certain extent after, then recover photovoltaic generation input.
After distribution network failure recovers, in order to avoid it is grid-connected when produce larger dash current, before grid-connected switch closure, it is necessary toAdjust the amplitude and phase of energy storage device output voltage, its is tracked network voltage, amplitude tracking, can by gradually increasing orThe amplitude for reducing output voltage realizes that Phase Tracking can be realized by phaselocked loop.Upper computer detection is to the public coupling of microgridWhen the amplitude and phase of voltage at chalaza are with the amplitude and consistent phase of network voltage, control system, which sends instruction, makes grid-connected openClose and close.
Certainly, the above is only presently preferred embodiments of the present invention, it is impossible to is construed as limiting the implementation to the present inventionExample scope.The present invention is also not limited to the example above, essential scope of the those skilled in the art in the present inventionInterior made all the changes and improvements etc., should all belong in the patent covering scope of the present invention.