CN205429759U - Little grid system - Google Patents
Little grid system Download PDFInfo
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- CN205429759U CN205429759U CN201620102662.4U CN201620102662U CN205429759U CN 205429759 U CN205429759 U CN 205429759U CN 201620102662 U CN201620102662 U CN 201620102662U CN 205429759 U CN205429759 U CN 205429759U
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Abstract
The utility model relates to a little grid system, including battery, energy storage converter, observation circuit and controllable switch. Little grid system is when being incorporated into the power networks the mode, and invariable power is exported to the energy storage converter under the control of current loop unit, and control is not participated in to the voltage outer ring unit under the mode of being incorporated into the power networks, nevertheless still be in running state, and it generates out the electric current loop set signal that little grid system was incorporated into the power networks and cuts the isolated island mode in advance according to four incoming signal of voltage outer ring unit. Little grid system is by being incorporated into the power networks mode switch during to the isolated island mode, and the voltage outer ring unit puts into operation into operation, electric current loop set signal control energy storage converter output voltage and frequency invariant that the current loop unit came out according to the estimation in advance of voltage outer ring unit output. Above -mentioned little grid system, voltage outer ring unit controlled its output around mode switch electric current loop set signal is the same, can realize being incorporated into the power networks / isolated island mode seamless handover.
Description
Technical field
This utility model relates to power supply technical field, particularly relates to a kind of micro-grid system.
Background technology
Micro-grid system is to include distributed power generation unit, energy accumulation current converter and load, and has the small distribution subnet of certain self regulation and control ability.It both can run with grid-connect mode, it is also possible to runs with island mode when electrical grid failure.The development of renewable energy utilization and distributed power generation of micro-capacitance sensor promoting technology, enjoys the countries in the world to pay attention to.
In micro-grid system, energy accumulation current converter is the core of whole micro-grid system, stores energy when grid-connect mode runs, and when island mode runs as the main power source of micro-grid system, provides voltage and the support of frequency for whole micro-grid system.The key problem of micro-grid system is how to reduce the switching shock caused when micro-grid system is switched to island mode by grid-connect mode thus realizes seamless switching at present, but seamless switching to be realized yet suffers from technical difficult point, in some instances it may even be possible to cause micro-grid system unstability.
Utility model content
Based on this, for the above-mentioned switching shock how reducing and causing when micro-grid system is switched to island mode by grid-connect mode, this utility model provides a kind of micro-grid system, the switching shock caused when micro-grid system is switched to island mode by grid-connect mode can be reduced, it is achieved grid-connected/island mode seamless switching.
A kind of micro-grid system, including accumulator, also includes energy accumulation current converter, observation circuit and gate-controlled switch；Described gate-controlled switch is connected between civil power and ac bus；Described energy accumulation current converter is connected with described accumulator, described ac bus respectively；Described observation circuit is connected with described energy accumulation current converter, described gate-controlled switch respectively；
Described observation circuit, for being monitored the running status of civil power and exporting the first monitoring signal when civil power is normal, exports the second monitoring signal when city's electrical anomaly；Described gate-controlled switch turns under the control monitoring signal described first, the entrance grid-connect mode so that described micro-grid system and civil power are incorporated into the power networks；Described gate-controlled switch is additionally operable to disconnect under the described second control monitoring signal, so that described micro-grid system independently powers to the load, enters island mode；
Described energy accumulation current converter includes main circuit and control circuit；Described main circuit is for processing the output voltage of described accumulator with grid-connected or power to the load；Described control circuit is for being controlled the output of described main circuit；Described control circuit includes outer voltage unit, mode selector switch and current inner loop unit；
The first input end of described current inner loop unit is connected with the outfan of described energy accumulation current converter, to receive the output current feedback values of energy accumulation current converter；Second input of described current inner loop unit is connected with the fixing end of described mode selector switch；The outfan of described current inner loop unit is connected with described main circuit；First contact of described mode selector switch is used for receiving current inner loop and gives current value；
The first input end of described outer voltage unit is connected with the outfan of described energy accumulation current converter, to receive the output voltage value of feedback of energy accumulation current converter；Second input of described outer voltage unit is used for receiving outer voltage and gives magnitude of voltage；3rd input of described outer voltage unit is electrically connected with city by described gate-controlled switch, to receive mains current value；The four-input terminal of described outer voltage unit is used for receiving described current inner loop and gives current value；The outfan of described outer voltage unit is connected with the second contact of described mode selector switch；The output voltage value of feedback of the energy accumulation current converter that the outer voltage of the second input input that described outer voltage unit gives current value, the mains current value of the 3rd input input of outer voltage unit, outer voltage unit for the current inner loop that the four-input terminal according to described outer voltage unit inputs gives the first input end input of magnitude of voltage and outer voltage unit forms the grid-connected electric current loop Setting signal cutting island mode of micro-grid system；
Mode selector switch is for connecting the first contact under the control of the first monitoring signal, the output current feedback values that current inner loop unit gives current value and energy accumulation current converter according to the current inner loop that the first contact inputs generates control signal, the power constant to control energy accumulation current converter output；Mode selector switch is additionally operable to connect the second contact under the control of the second monitoring signal, electric current loop Setting signal and the output current feedback values of energy accumulation current converter that current inner loop unit exports according to described outer voltage unit generate control signal, to control output voltage and the frequency-invariant of energy accumulation current converter.
Wherein in an embodiment, described main circuit includes current transformer；Described control circuit also includes drive signal generator；Described drive signal generator is connected between outfan and the control end of described current transformer of described current inner loop unit；Described drive signal generator drives signal, to be controlled described current transformer accordingly for generating according to described control signal.
Wherein in an embodiment, described main circuit also includes filter circuit；Described filter circuit is connected between outfan and the ac bus of described current transformer, for being filtered processing to the output of current transformer.
Wherein in an embodiment, described current inner loop unit includes electric current loop adder and the current loop controller being serially connected；The outfan of described electric current loop adder is connected with described current loop controller, and the outfan of described current loop controller is connected with described drive signal generator；Described electric current loop adder obtains error signal for subtracting each other two input signals of first input end and the second input；Described current loop controller is for forming control signal according to described error signal.
Wherein in an embodiment, described outer voltage unit includes the first Voltage loop adder, Voltage loop controller and the second Voltage loop adder being serially connected；Described Voltage loop controller is connected between described first Voltage loop adder and described second Voltage loop adder；Described first Voltage loop adder is for carrying out subtracting each other obtaining voltage error value according to the voltage signal of described first input end and described second input input；Described Voltage loop controller is for generating controlled quentity controlled variable according to described voltage error value；Described second Voltage loop adder is for generating electric current loop Setting signal to mains current value, the current inner loop set-point of four-input terminal input and the described controlled quentity controlled variable of described 3rd input input.
Wherein in an embodiment, described current loop controller and described Voltage loop controller are pi regulator.
Wherein in an embodiment, described current inner loop unit also includes that the first three-phase static coordinate system is tied to three-phase static coordinate system modular converter to biphase rotating coordinate system modular converter and biphase rotational coordinates；Described electric current loop adder includes electric current loop d axle adder and electric current loop q axle adder；Described current loop controller includes electric current loop d axis controller and electric current loop q axis controller；Described first three-phase static coordinate system is connected to the input of biphase rotating coordinate system modular converter and the outfan of described energy accumulation current converter, and the outfan of described first three-phase static coordinate system to biphase rotating coordinate system modular converter is connected with described electric current loop d axle adder and electric current loop q axle adder respectively；Described first three-phase static coordinate system is changed to generate d shaft current and q shaft current to biphase rotating coordinate system modular converter for the three-phase current exporting described energy accumulation current converter；Described biphase rotational coordinates is tied to the input of the three-phase static coordinate system modular converter outfan respectively with described electric current loop d axis controller and electric current loop q axis controller and is connected, and described biphase rotational coordinates is tied to the outfan of three-phase static coordinate system modular converter and is connected with described drive signal generator；Described biphase rotational coordinates is tied to three-phase static coordinate system modular converter and is converted into three-phase modulations signal for the amount of the amount exported by described electric current loop d axis controller and the output of described electric current loop q axis controller, output is to described drive signal generator, in order to generate the drive control signal of described current transformer；
Described outer voltage unit also includes that the second three-phase static coordinate system is to biphase rotating coordinate system modular converter and the 3rd three-phase static coordinate system to biphase rotating coordinate system modular converter；Described first Voltage loop adder includes the first Voltage loop d axle adder and the first Voltage loop q axle adder；Described Voltage loop controller includes Voltage loop d axis controller and Voltage loop q axis controller；Described second Voltage loop adder includes the second Voltage loop d axle adder and the second Voltage loop q axle adder；Described second three-phase static coordinate system is connected to the input of biphase rotating coordinate system modular converter and the outfan of described energy accumulation current converter, and the outfan of described second three-phase static coordinate system to biphase rotating coordinate system modular converter input with described first Voltage loop d axle adder, described first Voltage loop q axle adder respectively is connected；Described second three-phase static coordinate system is changed to generate d shaft voltage and q shaft voltage to biphase rotating coordinate system modular converter for the three-phase voltage exporting described energy accumulation current converter；Described 3rd three-phase static coordinate system is used for receiving mains current to the input of biphase rotating coordinate system modular converter；Described 3rd three-phase static coordinate system is connected with described second Voltage loop d axle adder, described second Voltage loop q axle adder respectively to the outfan of biphase rotating coordinate system modular converter；Described 3rd three-phase static coordinate system is used for changing to generate d shaft current and q shaft current to the three-phase current of civil power to biphase rotating coordinate system modular converter；Described current inner loop gives current value and includes that current inner loop d axle gives current value and current inner loop q axle gives current value；Described outer voltage gives magnitude of voltage and includes that outer voltage d axle gives magnitude of voltage and outer voltage q axle gives magnitude of voltage；
Described mode selector switch includes d axle mode selector switch and q axle mode selector switch；Described d axle mode selector switch is connected between described electric current loop d axle adder and the second Voltage loop d axle adder；Described q axle mode selector switch is connected between electric current loop q axle adder and the second Voltage loop q axle adder.
Wherein in an embodiment, described micro-grid system also includes photovoltaic electrification component；Described photovoltaic electrification component includes photovoltaic cell component and the photovoltaic DC-to-AC converter being attached thereto；Described photovoltaic electrification component is used for converting light energy into powering load after electric energy, and exports to electrical network or described accumulator when the electric energy produced is more than loading demand electricity.
Observation circuit in above-mentioned micro-grid system controls gate-controlled switch conducting and control mode switch switch connection the first contact when civil power is normal, micro-grid system enters grid-connect mode, the output current feedback values that current inner loop unit gives current value and energy accumulation current converter according to current inner loop generates control signal, and the energy accumulation current converter controlling micro-grid system has constant power to export；Outer voltage unit is not involved in controlling under grid-connect mode, remain at running status, it gives current value according to four input signals of outer voltage unit, i.e. current inner loop, mains current value, outer voltage give the output voltage value of feedback of magnitude of voltage and energy accumulation current converter and form the grid-connected electric current loop Setting signal cutting island mode of micro-grid system.Observation circuit is when monitoring city's electrical anomaly, control gate-controlled switch to disconnect and control mode switch switch connection the second contact, when micro-grid system is switched to island mode by grid-connect mode, electric current loop Setting signal and the output current feedback values of energy accumulation current converter that current inner loop unit exports according to outer voltage unit generate control signal, to control output voltage and the frequency-invariant of energy accumulation current converter.Above-mentioned micro-grid system, outer voltage unit electric current loop Setting signal of its output before and after pattern switches is identical, there is no big sudden change, reduce the switching shock caused when micro-grid system is switched to island mode by grid-connect mode, it is achieved that grid-connected/island mode seamless switching.
Accompanying drawing explanation
Fig. 1 is the structural representation of the micro-capacitance sensor system of an embodiment；
Fig. 2 is the circuit block diagram of the energy accumulation current converter in the micro-grid system of embodiment illustrated in fig. 1；
Fig. 3 is the circuit theory diagrams of the outer voltage unit in embodiment illustrated in fig. 2；
Fig. 4 is the circuit theory diagrams of the current inner loop unit in embodiment illustrated in fig. 2；
Fig. 5 is the circuit theory diagrams of the energy accumulation current converter in the micro-grid system in an embodiment；
Fig. 6 be shown in Fig. 5 in micro-grid system at the effect schematic diagram of grid-connected/isolated island seamless switching process.
Detailed description of the invention
The micro-grid system provided for clearer explanation this utility model, explains below in conjunction with embodiment.
A kind of micro-grid system can operate at grid-connect mode and island mode, and its structural representation is as shown in Figure 1.This micro-grid system includes accumulator 5000, energy accumulation current converter 1000, gate-controlled switch 2000, photovoltaic electrification component 3000, observation circuit (not shown) and master controller (not shown).Wherein, gate-controlled switch 2000 one end electrically connects with city, and the other end passes through PCC (points of common connection) incoming transport bus.Energy accumulation current converter 1000 one end is connected with accumulator, and the other end is connected with ac bus.Observation circuit is connected with energy accumulation current converter 1000, gate-controlled switch 2000 respectively.
Observation circuit, for being monitored the running status of civil power and exporting the first monitoring signal when civil power is normal, exports the second monitoring signal when city's electrical anomaly.In the present embodiment, civil power is just referring to the voltage of civil power and is being in steady statue, (in the short time, voltage has bigger lifting or decline) will not occur drastically to change and can normally export and be powered to load；City's electrical anomaly then refers to that the voltage of civil power plays pendulum or interrupts (i.e. can not normally export powering load) state.
Gate-controlled switch 2000 is for turning under the control of the first monitoring signal, the entrance grid-connect mode so that micro-grid system and civil power are incorporated into the power networks, and gate-controlled switch 2000 is additionally operable to disconnect under the control of the second monitoring signal, so that this micro-grid system is independent to load 4000 power supply, enter island mode.
Photovoltaic electrification component 3000 is powered to load 4000 after being used for converting light energy into electric energy, and exports to electrical network or accumulator when the electric energy produced is more than load 4000 demand electricity, and it includes photovoltaic cell component and photovoltaic DC-to-AC converter.
Master controller is for obtaining the severity level of load, and carries out electric energy distribution when micro-grid system is in island mode according to the severity level loading 4000.Under normal circumstances, load 4000 includes important load and controllable load.
Above-mentioned micro-grid system, observation circuit exports the first monitoring signal, controls gate-controlled switch 2000 and close when civil power is normal, and micro-grid system works in grid-connect mode.When micro-grid system works in grid-connect mode, photovoltaic electrification component 3000 and electrical network give load 4000 power supply simultaneously.If the power of photovoltaic electrification component 3000 output is more than load 4000 power, then unnecessary electric energy is exported to electrical network or is charged accumulator 5000 to by energy accumulation current converter 1000 by photovoltaic electrification component 3000, and then makes accumulator 5000 can store energy.Observation circuit exports the second monitoring signal when city's electrical anomaly, controls gate-controlled switch 2000 and disconnects, and micro-grid system works in island mode.Energy accumulation current converter 1000 is rapidly switched to island mode from grid-connect mode, thus provides constant voltage and the support of frequency for whole micro-grid system.At this moment load 4000 is powered by photovoltaic electrification component 3000 and accumulator 5000 simultaneously.The power of load 4000 also can be detected by master controller, and when output sum (i.e. the loading 4000 power power supply ability to bear beyond photovoltaic electrification component 3000 and accumulator 5000) that load 4000 power are more than photovoltaic electrification component 3000 and accumulator 500 being detected, controllable load is excised, thus only important load is powered, to guarantee the continued power of important load.
In other examples, micro-grid system can also use other distributed energies such as diesel-driven generator, wind power generation system etc. to replace the photovoltaic electrification component in the present embodiment, or it is co-located in micro-grid system with the photovoltaic electrification component in the present embodiment, with the power capability that offer is stronger.
Above-mentioned energy accumulation current converter 1000 uses PQ control strategy under grid-connect mode, uses VF control strategy thus provides voltage and the support of frequency for whole micro-grid system, it is ensured that load 4000 uninterrupted power supplies under island mode.Wherein, energy accumulation current converter 1000 is according to energy conservation principle, take the most in advance under grid-connect mode it can be avoided that the related measure of switching shock occurs when energy accumulation current converter 1000 is switched to island mode by grid-connect mode, below will be described in detail the relative theory of energy accumulation current converter 1000.
Fig. 2 is the circuit block diagram of the energy accumulation current converter 1000 in Fig. 1.Seeing Fig. 2, energy accumulation current converter 1000 includes main circuit 1100 and control circuit 1200.Main circuit 1100 is for processing the output voltage of accumulator 5000 with to electrical network or load 4000 power supply.Main circuit 1100 includes current transformer 1110 and filter circuit 1120.Filter circuit 1120 is connected between the outfan of current transformer 1110 and PCC point, for being filtered processing to the output of current transformer 1110.Concrete, filter circuit 1120 is LC filter circuit.In the present embodiment, current transformer 1110 is two way convertor.When grid-connect mode, when the energy storage of accumulator 5000 is less than preset value, accumulator 5000 is charged by civil power or photovoltaic electrification component 3000 via current transformer 1110, with the energy loss of supplementary accumulator 5000.When island mode, load 4000 power supply given after changing the output electric energy of accumulator 5000 by current transformer 1110.
Control circuit 1200 is the main execution circuit of above-mentioned PQ control strategy and VF control strategy, for being controlled the output of main circuit 1100.Control circuit 1200 includes drive signal generator 1210, current inner loop unit 1220, mode selector switch 1230 and outer voltage unit 1240.
The first input end of outer voltage unit 1240 is connected with the outfan of current transformer 1110, to receive output voltage value of feedback U of current transformer 1110.Second input of outer voltage unit 1240 is used for receiving outer voltage and gives magnitude of voltage Uref *.3rd input incoming transport bus of outer voltage unit 1240, and electrically connected with city by gate-controlled switch 2000, to receive mains current value Ig.The four-input terminal of outer voltage unit 1240 is used for receiving current inner loop and gives current value Iref *.The outfan of outer voltage unit 1240 is connected with the second contact 2 of mode selector switch 1230.Outer voltage unit 1240 for giving magnitude of voltage U to outer voltageref *Through being processed generation controlled quentity controlled variable by Voltage loop controller after obtaining voltage error value with output voltage value of feedback U of current transformer 1110 after subtracting each other, and this controlled quentity controlled variable and current inner loop are given current value Iref *And mains current value IgCarry out being added thus obtain electric current loop Setting signal uvo。
The circuit theory diagrams of outer voltage unit 1240 are as shown in Figure 3.Seeing Fig. 3, outer voltage unit 1240 includes the first Voltage loop adder 310, Voltage loop controller 320 and the second Voltage loop adder 330 being serially connected.Wherein, Voltage loop controller 320 is connected between the first Voltage loop adder 310 and the second Voltage loop adder 330.Output voltage value of feedback U of the current transformer 1110 that the first Voltage loop adder 310 inputs for the first input end according to outer voltage unit 1240 and the outer voltage of the second input input give magnitude of voltage Uref *Carry out subtracting each other obtaining voltage error value.Voltage loop controller 320 is for generating controlled quentity controlled variable Δ u according to this voltage error value.Second Voltage loop adder 330 is for giving current value I to mains current value Ig of the 3rd input input of outer voltage unit 1240, the current inner loop of four-input terminal inputref *And the controlled quentity controlled variable Δ u that generates of Voltage loop controller 320 carries out being added and obtains grid-connected electric current loop Setting signal u when cutting island modevo.Therefore, electric current loop Setting signal uvoFor:
uvo=Δ u+Iref *+Ig。
Wherein, Δ u, Iref *Deng all representing the controlled quentity controlled variable obtained by voltage or electric current, it is not offered as current value or magnitude of voltage.Outer voltage unit 1240 is constantly in duty, therefore can estimate in advance when grid-connected micro-grid system grid-connected cut island mode time need the bearing power that undertakes.
Seeing Fig. 2, the first input end of current inner loop unit 1220 is connected with the outfan of energy accumulation current converter 1000, to receive the output current feedback values I of energy accumulation current converter 1000.Second input of current inner loop unit 1220 is connected with the fixing end of mode selector switch 1230, to receive the current signal I that fixing end transmission comes*.The outfan of current inner loop unit 1220 is connected with current transformer 1110 by drive signal generator 1210.First contact 1 of mode selector switch 1230 is used for receiving current inner loop and gives current value Iref *.Second contact 2 of mode selector switch 1230 is for receiving the electric current loop Setting signal u of outer voltage unit 1240 outputvo。
The concrete structure of current inner loop unit 1220 is as shown in Figure 4.Seeing Fig. 4, current inner loop unit 1220 includes electric current loop adder 410 and the current loop controller 420 being serially connected.The outfan of electric current loop adder 410 is connected with current loop controller 420, and the outfan of current loop controller 420 is connected with drive signal generator 1210.Electric current loop adder 410 obtains error signal for subtracting each other two input signals of first input end and the second input, and current loop controller 420 is for forming control signal u according to this error signalo, and then control the output of energy accumulation current converter 1000.In the present embodiment, current loop controller 420 and outer voltage controller 320 are pi regulator.Specifically, when mode selector switch 1230 connects the first contact 1 under the control of the first monitoring signal, when i.e. micro-grid system is in grid-connect mode, the current signal I of the second input input of electric current loop adder 410*Current value I is given for current inner loopref *, electric current loop adder 410 gives current value I to current inner loopref *Obtaining error signal with the output current feedback values I of current transformer 1110 after subtracting each other, current loop controller 420 is for generating control signal u according to this error signalo.When mode selector switch 1230 is switched to access the second contact 2 by the first contact 1 under the control of the second monitoring signal, namely micro-grid system is when grid-connect mode is switched to island mode, the circuit signal I of the second input input of electric current loop adder 410*Electric current loop Setting signal u for outer voltage unit 1240 outputvo.Current value I is given with the current inner loop of the second input input time grid-connectedref *Relatively, when pattern switches, moment has had more and estimates metering and be:
uvo-Iref *=(Δ u+Iref *+ Ig)-Iref *=Δ u+Ig,
Thus energy accumulation current converter 1000 output size is constant before and after maintaining pattern switching, causes actuator output saturated when overcoming conventional voltage ring moment input, cause exporting the system protection that current break causes.The electric current loop Setting signal u that outer voltage unit 1240 is exported by electric current loop adder 410voObtaining error signal with the output current feedback values I of current transformer 1110 after subtracting each other, current loop controller 420 is for generating control signal u according to this error signalo。
Drive signal generator 1210 is for control signal u according to current loop controller 420 outputoGenerate and drive signal, so that current transformer 1110 is controlled.In one embodiment, drive signal generator 1210 is SPWM signal generator, and current transformer 1110 is PWM converter.
Observation circuit in above-mentioned micro-grid system controls gate-controlled switch 2000 and turns on and control mode switch switch 1230 connection the first contact 1 when civil power is normal, and micro-grid system enters grid-connect mode, and current inner loop unit 1220 gives current value I according to current inner loopref *Control signal u is generated with the output current feedback values I of energy accumulation current convertero, the energy accumulation current converter 1000 controlling micro-grid system has constant power to export.Outer voltage unit 1240 is not involved in controlling under grid-connect mode, remains at running status, and it gives magnitude of voltage U to outer voltageref *Through being processed generation controlled quentity controlled variable Δ u by Voltage loop controller 320 after obtaining voltage error value after subtracting each other with output voltage value of feedback U of current transformer 1110, and voltage control quantity Δ u is given current value I with current inner loopref *And mains current value IgCarry out being added thus obtain electric current loop Setting signal uvo.Observation circuit is when monitoring city's electrical anomaly, control gate-controlled switch 2000 to disconnect and control mode switch switch 1230 connection the second contact 2, when micro-grid system is switched to island mode by grid-connect mode, the electric current loop Setting signal u that current inner loop unit 1220 exports according to outer voltage unit 1240voControl signal u is generated with the output current feedback values I of energy accumulation current converter 1000o, to control output voltage and the frequency-invariant of energy accumulation current converter 1000.Above-mentioned micro-grid system, outer voltage unit 1240 is the electric current loop Setting signal u of its output before and after pattern switchesvoIdentical, there is no big sudden change, reduce the switching shock caused when micro-grid system is switched to island mode by grid-connect mode, it is achieved that grid-connected/island mode seamless switching.
Fig. 5 is the circuit theory diagrams of the micro-grid system in an embodiment.In the present embodiment, for guaranteeing that the output of energy accumulation current converter meets actual loading demand, reactive power and active power part are processed to obtain corresponding meritorious and reactive component control signal by control circuit respectively, are controlled with the output to energy accumulation current converter.Therefore, current inner loop unit 1220 includes d axle branch road and q axle branch road, and outer voltage unit 1240 includes d axle branch road and q axle branch road equally.Mode selector switch includes d axle mode selector switch SW1 and q axle mode selector switch SW2.Wherein d axle mode selector switch SW1 is connected between the d axle branch road of current inner loop unit and the d axle branch road of outer voltage unit, and q axle mode selector switch SW2 is then connected between the q axle branch road of current inner loop unit and the q axle branch road of outer voltage unit.
In the present embodiment, outer voltage unit 1240 also include the second three-phase static coordinate system to biphase rotating coordinate system modular converter (i.e. abc/dq modular converter) 340 and the 3rd three-phase static coordinate system to biphase rotating coordinate system modular converter (i.e. abc/dq modular converter) 350, and the second three-phase static coordinate system is used to realize abc three-phase static coordinate system to the conversion of the biphase rotating coordinate system of dq to biphase rotating coordinate system modular converter 340 and the 3rd three-phase static coordinate system to biphase rotating coordinate system modular converter 350.First Voltage loop adder 310 includes the first Voltage loop d axle adder 312 and the first Voltage loop q axle adder 314.Voltage loop controller 320 includes that Voltage loop d axis controller 322 and Voltage loop q axis controller 324, the second Voltage loop adder 330 include the second Voltage loop d axle adder 332 and the second Voltage loop q axle adder 334.Outer voltage gives magnitude of voltage Uref *Magnitude of voltage U is given including outer voltage d axledref *Magnitude of voltage U is given with outer voltage q axleqref *.Second three-phase static coordinate system is connected to the input (i.e. the first input end of outer voltage unit 1240) of biphase rotating coordinate system modular converter 340 with the outfan of current transformer 1110, and the outfan of the second three-phase static coordinate system to biphase rotating coordinate system modular converter 340 input with first Voltage loop d axle adder the 312, first Voltage loop q axle adder 314 respectively is connected.Another input (i.e. the second input of outer voltage unit 1240) of first Voltage loop d axle adder the 312, first Voltage loop q axle adder 314 is respectively used to receive outer voltage d axle and gives magnitude of voltage Udref *Magnitude of voltage U is given with outer voltage q axleqref *.3rd three-phase static coordinate system is electrically connected with city to the input (i.e. the 3rd input of outer voltage unit 1240) of biphase rotating coordinate system modular converter 350 by gate-controlled switch 2000, is used for receiving mains current value.Specifically, the 3rd three-phase static coordinate system to biphase rotating coordinate system modular converter 350 input access PCC point grid side three phase network electric current (igA、igBAnd igC).3rd three-phase static coordinate system is connected with second Voltage loop d axle adder the 332, second Voltage loop q axle adder 334 respectively to the outfan of biphase rotating coordinate system modular converter 350.Simultaneously, second Voltage loop d axle adder the 332, second Voltage loop q axle adder 334 the most also has two other input, one of them input connects Voltage loop d axis controller 322, the outfan of Voltage loop q axis controller 324 respectively, and another input (i.e. the four-input terminal of outer voltage unit 1240) is respectively connected to current inner loop d axle and gives current value Idref *Current value I is given with current inner loop q axleqref *.First Voltage loop d axle adder 312 is connected the d axle branch road forming outer voltage unit 1240 successively with Voltage loop d axis controller the 322, second Voltage loop d axle adder 332.First Voltage loop q axle adder 314 is connected the q axle branch road forming outer voltage unit 1240 successively with Voltage loop q axis controller the 324, second Voltage loop q axle adder 334.
Second three-phase static coordinate system is used for receiving three-phase output voltage value u of current transformer 1110 to biphase rotating coordinate system modular converter 340A、uB、uC, and by uA、uB、uCBe converted to the biphase rotating coordinate system of dq by abc three-phase static coordinate system, thus generate d shaft voltage Ud, q shaft voltage Uq, then the d shaft voltage U that will generated, q shaft voltage UqDeliver to first Voltage loop d axle adder the 312, first Voltage loop q axle adder 314 respectively.The first Voltage loop d axle adder 312 d shaft voltage U to inputdMagnitude of voltage U is given with outer voltage d axledref *Carry out subtracting each other obtaining voltage error signal.The voltage error signal that Voltage loop d axis controller 322 exports according to the first Voltage loop d axle adder 312 generates controlled quentity controlled variable Δ ud.3rd three-phase static coordinate system receives the three phase network electric current i of PCC point grid side to biphase rotating coordinate system modular converter 350gA、igB、igC, and by three phase network electric current igA、igB、igCBe converted to the biphase rotating coordinate system of dq by abc three-phase static coordinate system and draw d shaft current I of civil powergd, q shaft current Igq.D shaft current I that will obtain againgd, q shaft current IgqOutput is to second Voltage loop d axle adder the 332, second Voltage loop q axle adder 334.The current inner loop d shaft current set-point I that input is inputted by the second Voltage loop d axle adder 332dref *, d shaft current I of civil powergdAnd the controlled quentity controlled variable Δ u of Voltage loop d axis controller 322 outputdIt is added, obtains given current signal uvdo, uvdo=Δ ud+Igd+Idref *.The operation principle of the q axle branch road that the first Voltage loop q axle adder 314, Voltage loop q axis controller 324 and the second Voltage loop q axle adder 334 are formed is identical with the operation principle of d axle branch road, does not repeats.
Specifically, current inner loop unit 1220 also includes that the first three-phase static coordinate system is tied to three-phase static coordinate system modular converter (i.e. dq/abc modular converter) 440 to biphase rotating coordinate system modular converter (i.e. abc/dq modular converter) 430 and biphase rotational coordinates.First three-phase static coordinate system to biphase rotating coordinate system modular converter 430 for realizing abc three-phase static coordinate system to the conversion of the biphase rotating coordinate system of dq, the i.e. three-phase current (i to current transformer 1110 outputa、ibAnd ic) carry out changing to generate d shaft current IdWith q shaft current Iq.Biphase rotational coordinates is tied to three-phase static coordinate system modular converter 440 for realizing the biphase rotating coordinate system of dq to the conversion of abc three-phase static coordinate system.Electric current loop adder 410 includes electric current loop d axle adder 412 and electric current loop q axle adder 414.Current loop controller 420 includes electric current loop d axis controller 422 and electric current loop q axis controller 424.Current inner loop gives current value Iref *Current value I is given including current inner loop d axledref *Current value I is given with current inner loop q axleqref *.Wherein, electric current loop d axle adder 412 is connected with electric current loop d axis controller 422 and is formed the d axle branch road of current inner loop unit 1220.Electric current loop q axle adder 414 and the series connection of electric current loop q axis controller 424 form the q axle branch road of current inner loop unit 1220.
Specifically, first three-phase static coordinate system is connected to the input of biphase rotating coordinate system modular converter 430 and the outfan of current transformer 1110, and the outfan of the first three-phase static coordinate system to biphase rotating coordinate system modular converter 430 is connected with electric current loop d axle adder 412 and electric current loop q axle adder 414 respectively.Biphase rotational coordinates is tied to the input of three-phase static coordinate system modular converter 440 outfan respectively with electric current loop d axis controller 422 and electric current loop q axis controller 424 and is connected, and biphase rotational coordinates is tied to the outfan of three-phase static coordinate system modular converter 440 and is connected with drive signal generator (SPWM) 1210.Signal generator 1210 is connected between the outfan of current inner loop unit 1220 and the control end of current transformer 1110.In the present embodiment, the electric current loop d axle adder 412 d shaft current I to inputdThe current signal I inputted with the fixing end of d axle mode selector switch SW1d *Carry out subtracting each other obtaining error signal.Specifically, when d axle mode selector switch SW1 connects the first contact 1, the current signal I of fixing end outputd *Current value I is given for electric current loop d axledref *；When d axle mode selector switch SW1 connects the second contact 2, the current signal I of fixing end outputd *Electric current loop Setting signal u for outer voltage unit 1240 outputvdo.The error signal that electric current loop d axis controller 422 exports according to electric current loop d axle adder 412 generates d axle control signal udo.The work process of the q axle branch road of current inner loop unit 1220 is identical with d axle branch road.Therefore, electric current loop q axis controller 424 similarly generates q axle control signal uqo.Biphase rotational coordinates is tied to three-phase static coordinate system modular converter 440 then for d axle control signal udoWith q axle control signal uqoCarry out conversion and generate three-phase modulations signal (Varef、VbrefAnd Vcref).The three-phase modulations signal generation that drive signal generator 1210 is tied to three-phase static coordinate system modular converter 440 output according to biphase rotational coordinates drives signal, accordingly to be controlled current transformer 1110.
The work process of above-mentioned micro-grid system is as follows:
(1) grid-connect mode
When monitoring circuit monitors to civil power normal power supply, generate the first monitoring signal.Gate-controlled switch 2000 turns under the control of the first monitoring signal, so that micro-grid system enters grid-connect mode.During grid-connect mode, load is powered by electrical network and micro-grid system simultaneously.Micro-grid system, when grid-connect mode, uses PQ control strategy, i.e. controls current transformer 1110 and exports constant power.Micro-grid system also can be connected to the grid when the generated energy of photovoltaic electrification component 3000 is more than the power of load or charge to accumulator 5000.Meanwhile, d axle mode selector switch SW1 and q axle mode selector switch SW2 connects the first contact 1, the signal I that the fixing end of d axle mode selector switch SW1, q axle mode selector switch SW2 transmits under the control of the first monitoring signald *、Iq *Then it is respectively current inner loop d axle and gives current value Idref *, current inner loop q axle give current value Iqref *.Therefore the error signal that electric current loop d axle adder 412, electric current loop q axle adder 414 draw is that current inner loop d axle is given current value Idref *, current inner loop q axle give current value Iqref *Respectively with d shaft current I of current transformer 1110d, q shaft current IqSubtract each other and draw.At this moment, the error signal that electric current loop d axis controller 322 and electric current loop q axis controller 324 export according to corresponding adder generates control signal udoAnd uqo.Drive signal generator 1210 then to generate three-phase modulations signal to current transformer 1110 according to this control signal, export constant power controlling current transformer 1110.
When grid-connect mode, outer voltage unit 1240 is not involved in the output of current transformer 1110 and controls, and remains at running status.Outer voltage unit 1240 can precompute electric current loop Setting signal u under grid-connect modevo(i.e. uvdo=Δ ud+Igd+Idref *, uvqo=Δ uq+Igq+Iqref *), to provide given current signal u to current inner loop unit 1220 when grid-connected/island mode switches and under island modevo。
(2) grid-connected switching island mode
Observation circuit exports the second monitoring signal when monitoring city's electrical anomaly.Gate-controlled switch 2000 disconnects under the control of the second monitoring signal, so that micro-grid system is independent to load 4000 power supply, whole micro-grid system is switched to island mode by grid-connect mode.Energy accumulation current converter 1000 uses the control strategy (i.e. VF control strategy) of outer voltage current inner loop, and then exports constant voltage and frequency.D axle mode selector switch SW1 and q axle mode selector switch SW2 is switched to connect the state of the second contact 2 by the state connecting the first contact 1 under the control of the second monitoring signal, and energy accumulation current converter 1000 i.e. takes the control strategy of outer voltage current inner loop.The current signal I that now the fixing end of d axle mode selector switch SW1 and q axle mode selector switch SW2 transmitsd *、Iq *It is respectively electric current loop Setting signal (the i.e. u of second Voltage loop d axle adder the 332, second Voltage loop q axle adder 334 outputvdo=Δ ud+Igd+Idref *, uvqo=Δ uq+Igq+Iqref *).That is, before pattern switches, (i.e. grid-connect mode) outer voltage unit 1240 calculates electric current loop Setting signal u the most in advancevo, therefore before and after pattern switches, the output signal size of outer voltage unit 1240 is constant.And; when pattern switches, moment has had more and has estimated metering Δ u+Ig; thus current transformer 1110 output size is constant before and after maintaining pattern switching, causes actuator output saturated when overcoming conventional voltage ring moment input, cause exporting the system protection that current break causes.
Above-mentioned micro-grid system, outer voltage unit 1240 is the electric current loop Setting signal u of output before and after pattern switchesvoConstant, and export to current inner loop unit 1220 after switching moment and switching.Specifically, time grid-connected, the electric current loop Setting signal u of outer voltage unit 1240 outputvoFor: uvdo=Δ ud+Igd+Idref *, uvqo=Δ uq+Igq+Iqref *.When mode selector switch 1230 gates the second contact point 2, the fixing end of mode selector switch 1230 exports to the current signal I of current inner loop unit 1220*Current value I is given by original electric current loop d axledref *Current value I is given with electric current loop q axleqref *Become electric current loop Setting signal uvdoWith given current signal uvqo.Current value I is given with original current inner loopdref *、Iqref *Compare, be equivalent to estimate metering Δ u in pattern switching moment mored+Igd(or Δ uq+Igq); make outer voltage unit 1240 stable state output before and after pattern switching; and it is constant to maintain the size of energy accumulation current converter 1000 output before and after pattern switches; the actuator output caused when overcoming the outer instantaneous input of ring element of conventional voltage is saturated; cause exporting the system protection that causes of current break, it is achieved thereby that system from the grid-connected and seamless switching of island mode.
Connect down as a example by d axle, illustrate that the present embodiment realizes the principle of seamless switching in pattern switching moment.
When micro-grid system is incorporated into the power networks, the current signal I that the fixing end of d axle mode selector switch SW1 transmitsd *Current value I is given for current inner loopdref *.Although at this moment outer voltage unit 1240 is not involved in controlling energy accumulation current converter 1000, but self is still running.Under grid-connect mode, outer voltage d axle gives magnitude of voltage Udref *D shaft voltage U with energy accumulation current converter 1000dOf substantially equal, therefore outer voltage d axle gives magnitude of voltage Udref *Deduct d shaft voltage UdAnd the voltage error value that draws is less, then the controlled quentity controlled variable Δ u drawn after Voltage loop d axis controller 322 computingd≈ 0, therefore the electric current loop Setting signal u of at this moment outer voltage unit 1240 outputvdoFor:
uvdo=Δ ud+Igd+Idref *=Igd+Idref *(1)
Above formula illustrates, the electric current loop Setting signal u of outer voltage unit 1240 output under grid-connect modevdoBe equivalent to d shaft current I of energy accumulation current converter 1000 outputdD shaft current I with civil powergdSum.If during energy accumulation current converter 1000 grid-connected no-load running, d shaft current I of energy accumulation current converter 1000 outputd=0, at this moment d shaft current I of civil powergdI.e. equal to load current.
Therefore, switch island mode moment at grid-connect mode, seamless taking over seamlessly will be realized, it is necessary to before and after maintaining switching, energy accumulation current converter 1000 output is constant with load 4000 watt levels.So according to power balance theory, the output P of energy accumulation current converter 1000 under island mode before and after switchingPCS1Should be equal to the output P of energy accumulation current converter 1000 under grid-connect modePCS0With the power P that electrical network gives load 4000 offergSum, it may be assumed that
PPCS1=Pg+PPCS0(2)
So corresponding conversion to d shaft current is:
Id=Igd+Idref *=uvdo(3)
From formula (1) and (3), formula (1), (3) are respectively outer voltage unit 1240 and switch the electric current loop Setting signal u of forward and backward output in patternvdo, and it is Igd+Idref *, therefore outer voltage unit 1240 stable state output before and after pattern switches, it is ensured that the output of outer voltage unit 1240 does not has big sudden change before and after pattern switches, it is to avoid exported current oscillation protection that is saturated and that cause by outer voltage unit 1240.
As an example it is assumed that energy accumulation current converter 1000 grid-connected output 0kW before pattern switching, electrical network gives load 4000 output 10kW, i.e. Idref *=Id=0, Igd=10, then uvdo=Igd+Idref *=10, the outer ring element 1240 of account for voltage estimate the most in advance energy accumulation current converter 1000 by grid-connected switch to island mode after need to undertake originally by electrical network to these Partial Powers (i.e. 10kW) of load 4000 output.When electrical network disconnect after electrical network export to load 4000 power be 0kW, and electrical network originally give load 4000 offer 10kW power should all shift into by energy accumulation current converter 1000 to load 4000 offer.
Therefore switching to island mode moment grid-connected, grid power is 0kW, and outer voltage unit 1240 puts into, i.e. outer voltage unit 1240 is connected by mode selector switch 1230 with current inner loop unit 1220.Owing to outer voltage unit 1240 calculates electric current loop Setting signal u the most in advancevdo=Igd+Idref *=10, as long as therefore mode selector switch 1230 connects the second contact, the u that outer voltage unit 1240 calculates in advancevdoCan be used as the given current signal of current inner loop unit 1220, and control energy accumulation current converter 1000 after switching moment and switching all to load 4000 offer 10kW power, thus to loading 4000 output power states of the same size before and after maintaining pattern switching, and stable state output before and after outer voltage unit 1240 switching, it is achieved that grid-connected/isolated island is seamless to be taken over seamlessly.
Fig. 6 is the effect schematic diagram in grid-connected/isolated island seamless switching process of the micro-grid system in the present embodiment.Figure illustrates as a example by A phase handoff procedure.Wherein uPCCAFor PCC point A phase line voltage, igAFor A phase power network current, iLAFor A phase load 4000 electric current, iAElectric current is exported for A phase energy accumulation current converter 1000.At t0Before moment, energy accumulation current converter 1000 works in grid-connect mode, and energy storage is exerted oneself the least, is mainly given load 4000 power supply by electrical network, therefore loads 4000 electric current iLANo better than power network current igA, i.e. iLA≈igA.At t0In the moment, electrical network disconnects, power network current igABeing zero, energy accumulation current converter 1000 is switched to island mode from grid-connect mode, and this moment is given load 4000 power supply by energy accumulation current converter 1000 as main power source, now loads 4000 electric current iLAIt is equal to the output current value i of energy accumulation current converter 1000A, i.e. iLA=iAIt is achieved that grid-connect mode remains constant to the size of load 4000 supply currents before and after switching to island mode; and seamlessly transit the most afterwards; solve and conventional grid-connected can cause exporting current break to island mode switching mode and cause the problem of system protection, thus the continued power of load 4000 in ensure that micro-grid system.
(3) island mode
When city's electrical anomaly, under the control of observation circuit, gate-controlled switch 2000 disconnects, and mode selector switch 1230 connects the second contact, and at this moment micro-grid system departs from electrical network.Energy accumulation current converter 1000, after switching completes, uses constant voltage/constant frequency (VF control) to control, i.e. the control strategy of outer voltage current inner loop.
In being embodied as, due to grid cut-off, at this moment electrical network stops to load 4000 power supply, and d axle, q axle give current value I simultaneouslydref *、Iqref *Also stopping accessing, therefore the electric current loop Setting signal of outer voltage unit 1240 output is uvdo=Δ ud+Igd+Idref *=Δ ud+ 0+0=Δ ud, uvqo=Δ uq+Igq+Iqref *=Δ uq+ 0+0=Δ uq, therefore the electric current loop Setting signal Δ u of outer voltage unit 1240 outputdWith Δ uqAs the given current signal that current inner loop unit 1220 is new, and with the current feedback signal I of corresponding energy accumulation current converter 1000d、IqDraw error signal after subtracting each other, then error signal is sent into electric current loop d axis controller and electric current loop q axis controller, after electric current loop d axis controller and electric current loop q axis controller computing, export control signal udoAnd uqo, then by control signal udoAnd uqoThree-phase modulations signal V is respectively obtained after being tied to the conversion of abc three-phase static coordinate system by the biphase rotational coordinates of dqaref, Vbref, Vcref, finally carry out SPWM modulation, produce the control driving signal to realize energy accumulation current converter 1000.Under island mode, mainly given load 4000 power supply by energy accumulation current converter 1000 as main power source, now load 4000 electric current iLAIt is equal to energy accumulation current converter 1000 output current value iA, i.e. iLA=iA。
In this micro-grid system, outer voltage unit 1240 electric current loop Setting signal of its output before and after pattern switches is identical, there is no big sudden change, reduce the switching shock caused when micro-grid system is switched to island mode by grid-connect mode, it is achieved that grid-connected/island mode seamless switching.
Each technical characteristic of embodiment described above can combine arbitrarily, for making description succinct, the all possible combination of each technical characteristic in above-described embodiment is not all described, but, as long as the combination of these technical characteristics does not exist contradiction, all it is considered to be the scope that this specification is recorded.
Above example only have expressed several embodiments of the present utility model, and it describes more concrete, but therefore can not be interpreted as the restriction to utility model patent scope.Being to be noted that for the person of ordinary skill of the art, without departing from the concept of the premise utility, it is also possible to make some deformation and improvement, these broadly fall into protection domain of the present utility model.Therefore, the protection domain of this utility model patent should be as the criterion with claims.
Claims (8)
1. a micro-grid system, including accumulator, it is characterised in that also include energy accumulation current converter, observation circuit and gate-controlled switch；Described gate-controlled switch is connected between civil power and ac bus；Described energy accumulation current converter is connected with described accumulator, described ac bus respectively；Described observation circuit is connected with described energy accumulation current converter, described gate-controlled switch respectively；
Described observation circuit, for being monitored the running status of civil power and exporting the first monitoring signal when civil power is normal, exports the second monitoring signal when city's electrical anomaly；Described gate-controlled switch turns under the control monitoring signal described first, the entrance grid-connect mode so that described micro-grid system and civil power are incorporated into the power networks；Described gate-controlled switch is additionally operable to disconnect under the described second control monitoring signal, so that described micro-grid system independently powers to the load, enters island mode；
Described energy accumulation current converter includes main circuit and control circuit；Described main circuit is for processing the output voltage of described accumulator with grid-connected or power to the load；Described control circuit is for being controlled the output of described main circuit；Described control circuit includes outer voltage unit, mode selector switch and current inner loop unit；
The first input end of described current inner loop unit is connected with the outfan of described energy accumulation current converter, to receive the output current feedback values of energy accumulation current converter；Second input of described current inner loop unit is connected with the fixing end of described mode selector switch；The outfan of described current inner loop unit is connected with described main circuit；First contact of described mode selector switch is used for receiving current inner loop and gives current value；
The first input end of described outer voltage unit is connected with the outfan of described energy accumulation current converter, to receive the output voltage value of feedback of energy accumulation current converter；Second input of described outer voltage unit is used for receiving outer voltage and gives magnitude of voltage；3rd input of described outer voltage unit is electrically connected with city by described gate-controlled switch, to receive mains current value；The four-input terminal of described outer voltage unit is used for receiving described current inner loop and gives current value；The outfan of described outer voltage unit is connected with the second contact of described mode selector switch；The output voltage value of feedback of the energy accumulation current converter that the outer voltage of the second input input that described outer voltage unit gives current value, the mains current value of the 3rd input input of outer voltage unit, outer voltage unit for the current inner loop that the four-input terminal according to described outer voltage unit inputs gives the first input end input of magnitude of voltage and outer voltage unit forms the grid-connected electric current loop Setting signal cutting island mode of micro-grid system；
Mode selector switch is for connecting the first contact under the control of the first monitoring signal, the output current feedback values that current inner loop unit gives current value and energy accumulation current converter according to the current inner loop that the first contact inputs generates control signal, the power constant to control energy accumulation current converter output；Mode selector switch is additionally operable to connect the second contact under the control of the second monitoring signal, electric current loop Setting signal and the output current feedback values of energy accumulation current converter that current inner loop unit exports according to described outer voltage unit generate control signal, to control output voltage and the frequency-invariant of energy accumulation current converter.
Micro-grid system the most according to claim 1, it is characterised in that described main circuit includes current transformer；Described control circuit also includes drive signal generator；Described drive signal generator is connected between outfan and the control end of described current transformer of described current inner loop unit；Described drive signal generator drives signal, to be controlled described current transformer accordingly for generating according to described control signal.
Micro-grid system the most according to claim 2, it is characterised in that described main circuit also includes filter circuit；Described filter circuit is connected between outfan and the ac bus of described current transformer, for being filtered processing to the output of current transformer.
Micro-grid system the most according to claim 2, it is characterised in that described current inner loop unit includes electric current loop adder and the current loop controller being serially connected；The outfan of described electric current loop adder is connected with described current loop controller, and the outfan of described current loop controller is connected with described drive signal generator；Described electric current loop adder obtains error signal for subtracting each other two input signals of first input end and the second input；Described current loop controller is for forming control signal according to described error signal.
Micro-grid system the most according to claim 4, it is characterised in that described outer voltage unit includes the first Voltage loop adder, Voltage loop controller and the second Voltage loop adder being serially connected；Described Voltage loop controller is connected between described first Voltage loop adder and described second Voltage loop adder；Described first Voltage loop adder is for carrying out subtracting each other obtaining voltage error value according to the voltage signal of described first input end and described second input input；Described Voltage loop controller is for generating controlled quentity controlled variable according to described voltage error value；Described second Voltage loop adder is for generating electric current loop Setting signal to mains current value, the current inner loop set-point of four-input terminal input and the described controlled quentity controlled variable of described 3rd input input.
Micro-grid system the most according to claim 5, it is characterised in that described current loop controller and described Voltage loop controller are pi regulator.
Micro-grid system the most according to claim 5, it is characterised in that described current inner loop unit also includes that the first three-phase static coordinate system is tied to three-phase static coordinate system modular converter to biphase rotating coordinate system modular converter and biphase rotational coordinates；Described electric current loop adder includes electric current loop d axle adder and electric current loop q axle adder；Described current loop controller includes electric current loop d axis controller and electric current loop q axis controller；Described first three-phase static coordinate system is connected to the input of biphase rotating coordinate system modular converter and the outfan of described energy accumulation current converter, and the outfan of described first three-phase static coordinate system to biphase rotating coordinate system modular converter is connected with described electric current loop d axle adder and electric current loop q axle adder respectively；Described first three-phase static coordinate system is changed to generate d shaft current and q shaft current to biphase rotating coordinate system modular converter for the three-phase current exporting described energy accumulation current converter；Described biphase rotational coordinates is tied to the input of the three-phase static coordinate system modular converter outfan respectively with described electric current loop d axis controller and electric current loop q axis controller and is connected, and described biphase rotational coordinates is tied to the outfan of three-phase static coordinate system modular converter and is connected with described drive signal generator；Described biphase rotational coordinates is tied to three-phase static coordinate system modular converter and is converted into three-phase modulations signal for the amount of the amount exported by described electric current loop d axis controller and the output of described electric current loop q axis controller, output is to described drive signal generator, in order to generate the drive control signal of described current transformer；
Described outer voltage unit also includes that the second three-phase static coordinate system is to biphase rotating coordinate system modular converter and the 3rd three-phase static coordinate system to biphase rotating coordinate system modular converter；Described first Voltage loop adder includes the first Voltage loop d axle adder and the first Voltage loop q axle adder；Described Voltage loop controller includes Voltage loop d axis controller and Voltage loop q axis controller；Described second Voltage loop adder includes the second Voltage loop d axle adder and the second Voltage loop q axle adder；Described second three-phase static coordinate system is connected to the input of biphase rotating coordinate system modular converter and the outfan of described energy accumulation current converter, and the outfan of described second three-phase static coordinate system to biphase rotating coordinate system modular converter input with described first Voltage loop d axle adder, described first Voltage loop q axle adder respectively is connected；Described second three-phase static coordinate system is changed to generate d shaft voltage and q shaft voltage to biphase rotating coordinate system modular converter for the three-phase voltage exporting described energy accumulation current converter；Described 3rd three-phase static coordinate system is used for receiving mains current to the input of biphase rotating coordinate system modular converter；Described 3rd three-phase static coordinate system is connected with described second Voltage loop d axle adder, described second Voltage loop q axle adder respectively to the outfan of biphase rotating coordinate system modular converter；Described 3rd three-phase static coordinate system is used for changing to generate d shaft current and q shaft current to the three-phase current of civil power to biphase rotating coordinate system modular converter；Described current inner loop gives current value and includes that current inner loop d axle gives current value and current inner loop q axle gives current value；Described outer voltage gives magnitude of voltage and includes that outer voltage d axle gives magnitude of voltage and outer voltage q axle gives magnitude of voltage；
Described mode selector switch includes d axle mode selector switch and q axle mode selector switch；Described d axle mode selector switch is connected between described electric current loop d axle adder and the second Voltage loop d axle adder；Described q axle mode selector switch is connected between electric current loop q axle adder and the second Voltage loop q axle adder.
Micro-grid system the most according to claim 1, it is characterised in that described micro-grid system also includes photovoltaic electrification component；Described photovoltaic electrification component includes photovoltaic cell component and the photovoltaic DC-to-AC converter being attached thereto；Described photovoltaic electrification component is used for converting light energy into powering load after electric energy, and exports to electrical network or described accumulator when the electric energy produced is more than loading demand electricity.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105552962A (en) * | 2016-02-01 | 2016-05-04 | 易事特集团股份有限公司 | Micro-grid system and control method therefor |
| WO2021213255A1 (en) * | 2020-04-20 | 2021-10-28 | Ampd Energy Limited | Energy storage system and method of boosting an electrical power for outputting to a load |
| CN116826795A (en) * | 2023-06-01 | 2023-09-29 | 中能建储能科技(武汉)有限公司 | Energy storage power station non-planned island operation load distribution control equipment and method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105552962A (en) * | 2016-02-01 | 2016-05-04 | 易事特集团股份有限公司 | Micro-grid system and control method therefor |
| WO2017133269A1 (en) * | 2016-02-01 | 2017-08-10 | 易事特集团股份有限公司 | Microgrid system and method of controlling same |
| CN105552962B (en) * | 2016-02-01 | 2018-10-19 | 易事特集团股份有限公司 | Micro-grid system and its control method |
| US11101663B2 (en) | 2016-02-01 | 2021-08-24 | East Group Go., Ltd. | Microgrid system and method of controlling same |
| WO2021213255A1 (en) * | 2020-04-20 | 2021-10-28 | Ampd Energy Limited | Energy storage system and method of boosting an electrical power for outputting to a load |
| CN116826795A (en) * | 2023-06-01 | 2023-09-29 | 中能建储能科技(武汉)有限公司 | Energy storage power station non-planned island operation load distribution control equipment and method |
| CN116826795B (en) * | 2023-06-01 | 2024-03-15 | 中能建储能科技(武汉)有限公司 | Energy storage power station non-planned island operation load distribution control equipment and method |
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