CN106786485A - For the mains ripple suppressing method of direct-current grid under unbalanced load - Google Patents
For the mains ripple suppressing method of direct-current grid under unbalanced load Download PDFInfo
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- CN106786485A CN106786485A CN201710120041.8A CN201710120041A CN106786485A CN 106786485 A CN106786485 A CN 106786485A CN 201710120041 A CN201710120041 A CN 201710120041A CN 106786485 A CN106786485 A CN 106786485A
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- 238000000034 method Methods 0.000 title claims abstract description 15
- 238000005259 measurement Methods 0.000 claims abstract description 37
- 239000003990 capacitor Substances 0.000 claims abstract description 25
- 238000004146 energy storage Methods 0.000 claims abstract description 20
- 238000010248 power generation Methods 0.000 claims description 12
- 238000013461 design Methods 0.000 claims description 7
- 238000010521 absorption reaction Methods 0.000 claims description 5
- 238000009415 formwork Methods 0.000 claims description 5
- 238000007599 discharging Methods 0.000 claims description 3
- 230000001629 suppression Effects 0.000 abstract description 4
- 230000010349 pulsation Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000003068 static effect Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000011217 control strategy Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 210000001367 artery Anatomy 0.000 description 1
- 125000002619 bicyclic group Chemical group 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 238000007665 sagging Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/02—Arrangements for reducing harmonics or ripples
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
- H02J1/102—Parallel operation of dc sources being switching converters
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/14—Balancing the load in a network
-
- H02J3/383—
-
- H02J3/386—
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/388—Islanding, i.e. disconnection of local power supply from the network
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/70—Wind energy
- Y02E10/76—Power conversion electric or electronic aspects
Abstract
The invention discloses a kind of mains ripple suppressing method for direct-current grid under unbalanced load, including setting up direct-current grid, set up the DC voltage control system based on ultracapacitor, signal measurement and treatment, determine the power expression of ultracapacitor, the parameter of super capacitor energy storage device is designed, it is determined that control error ei, determine sliding-mode surface S, determine control rate D, judge whether to reach control targe, PWM.The present invention has simple structure, and control accuracy is high, the advantages of strong robustness；In laod unbalance, the present invention can realize the control targe of direct-current grid mains ripple under suppression unbalanced load.
Description
Technical field
The present invention relates to a kind of mains ripple suppressing method, more particularly to one kind is for direct-current grid under unbalanced load
Mains ripple suppressing method, belong to power supply control technical field.
Background technology
Direct-current grid uses DC distribution form, is conducive to various distributed power sources to coordinate control, it is possible to provide higher
The quality of power supply, thus as the new direction of micro-capacitance sensor technical research.However, direct-current grid there is also certain stability asking
Topic.Because real system often contains unbalanced load, fundamental wave negative sequence component can be introduced in AC load side, cause DC voltage
There is the pulsation of two frequencys multiplication, have a strong impact on the power supply quality of direct-current grid.Additionally, inverter output power under unbalanced load
Two frequency multiplication pulsating quantities, can produce secondary ripple wave electric current in the power supply and transverter of direct-current grid, have a strong impact on its service life.
Excessive ripple current can also damage the electrode and electrolyte of battery, reduce battery efficiency；Reduce the opto-electronic conversion of photovoltaic module
Efficiency, improves the operating cost of photovoltaic plant；Increase the on-state loss and current stress of transverter switching tube, waste transverter and hold
Amount.
Research under current unbalanced load, primarily directed to various topological sums control that load-side three-phase inverter is proposed
Strategy, is target to improve its output voltage waveforms, the equilibrium condition of three-phase voltage is met the requirement of the quality of power supply.Due to right
The control of load-side inverter output voltage waveform is essential, while the direct-current grid caused by the unbalance response for loading
Mains ripple problem also can not be ignored, accordingly, it would be desirable to consider to control DC voltage from other angles.
Regarding to the issue above, scholar proposes to absorb two double frequency powers using energy storage device, so as to suppress DC voltage arteries and veins
It is dynamic.Guoyi Xu et al. are in IEEE Transactions on Energy Conversion, 2012,27 (4)：1036-1045.
“Coordinated DC voltage control of wind turbine with embedded energy storage
System " discloses a kind of DC voltage ripple suppression side that direct-current grid is stored up for the wind with embedded energy-storage system
Method.Dc bus warp trackside transverter (line side converter, LSC) incoming transport power network.Energy-storage system and LSC
Droop control and bicyclic PI controls is respectively adopted.When the power output of blower fan has pulsation, by adjusting the intrinsic of PI controllers
The sagging coefficient of frequency and droop control device coordinates the electric current on dc bus, makes energy-storage system that band logical is shown as to electric current special
Property, and LSC shows as low-pass characteristic to electric current, then the flutter component of electric current will be absorbed by energy-storage system, that is, make pulsation
Power flows into energy-storage system, so as to ensure DC voltage stability.Dong Chen et al. are in IEEE Transactions on
Power Systems, 2012,27 (4)：1897-1905.“Autonomous DC voltage control of a DC
Microgrid with multiple slack terminals " disclose a kind of for the straight of multiterminal wind storage direct-current grid
Stream mains ripple suppressing method.Energy-storage system and grid-connected transverter are still respectively adopted droop control and PI controls.By under adjustment
Vertical coefficient and PI controllers time constant directly control the transmission function of power, pulsating power is flowed into energy-storage system, you can suppression
DC voltage ripple processed.Above method is the frequency response characteristic by controlling direct current bus bar stream or power transfer function
To realize control targe, although can realize preferable control effect, but control performance is influenceed greatly, and when debugging by parameter
Need to coordinate multiple parameters, process is more complicated.
The content of the invention
The technical problem to be solved in the present invention is to provide a kind of mains ripple for direct-current grid under unbalanced load
Suppressing method.
In order to solve the above technical problems, the technical solution adopted by the present invention is：
A kind of mains ripple suppressing method for direct-current grid under unbalanced load, comprises the following steps：
Step 1：Set up general direct-current grid：The direct-current grid is included by wind power generating set, blower fan measurement unit
Part, AC/DC transverters cascade the wind power generation unit of composition successively, are changed by battery, measuring battery element, a DC/DC
Stream device cascades the batteries to store energy unit of composition successively, by photovoltaic array, Photovoltaic measurement element, the 2nd DC/DC transverters successively
The photovoltaic generation unit of cascade composition, DC measurement element, combining inverter, the first AC measurment element, AC network are successively
Cascade is constituted and net unit, the 3rd DC/DC transverters, DC load cascade the DC load unit of composition successively, load inverse
Become the AC load unit that device, the second AC measurment element, AC load cascade composition successively, the control system of wind power generation unit
System, the control system of batteries to store energy unit, the control system of photovoltaic generation unit；The direct-current grid is with dc bus
Center, it is wind power generation unit, batteries to store energy unit, photovoltaic generation unit, DC load unit and AC load unit, grid-connected
Unit is connected into dc bus successively by the first to the 5th DC measurement element respectively, forms radial structure, and wherein direct current is born
Dc bus is connected into by the 4th DC measurement element after carrier unit and the parallel connection of AC load unit；The wind power generation unit
Control system, the control system of batteries to store energy unit, the input of the control system of photovoltaic generation unit give a dinner for a visitor from afar respectively machine survey
The output end of amount element, measuring battery element, Photovoltaic measurement element and DC measurement element, its output end meets AC/DC respectively
Transverter, a DC/DC transverters, the input of the 2nd DC/DC transverters；
Step 2：Set up the DC voltage control system based on ultracapacitor：The DC voltage control system includes super
The control of level capacitor, super capacitor measuring cell, the 4th DC/DC transverters, the 4th DC measurement element and ultracapacitor
System is constituted；The DC voltage control system is in parallel with the AC load in direct-current grid, by the 4th DC measurement unit
Part is connected into dc bus, and the input of the control system connects the super capacitor measuring cell, DC measurement element respectively
Output end, the input of its output termination the 4th DC/DC transverter；
Step 3：Signal measurement and treatment：By voltage sensor and the electricity of current sensor measurement load-side dc bus
Pressure udc, the electric current i of the AC load is flowed to by direct-current gridr, the input current i of load inverterc, ultracapacitor
Discharge current isc, ultracapacitor terminal voltage usc；Calculate the power P that direct-current micro-grid is supplied to loadr, the power of load absorption
PL；
Step 4：Determine the reference power of DC voltage control system
Wherein：U for DC voltage square, C is DC bus capacitor, and t is the time；
Step 5：Design the parameter of super capacitor energy storage device：
The capacity of ultracapacitor is：
In formula, PmaxIt is reference powerPeak value；Charging-discharging cycle is T, and charging process is ultracapacitor end in T/2
Voltage uscBy usc_initRise to usc_fin,
Filter inductance LDCFor：
Wherein：DBuckIt is the dutycycle under Buck patterns；fsRepresent the switching frequency of DC/DC transverters；ΔiscIt is circuit
The largest ripple current of permission；
Step 6：It is determined that control error ei
Wherein：It is the current reference value of ultracapacitor,
Step 7:Determine sliding-mode surface S：
S=ei+Ki∫eidt (5)
In formula：KiIt is arithmetic number；
Step 8:Determine the control rate D of sliding formwork control：
D=DeqIn+Δ D (6) formula：D is the dutycycle of DC/DC transverters, DeqIt is equivalent control, Δ D is switch control
System；
WhenWhen, ultracapacitor charges, and DC/DC transverters are operated in Buck patterns：
D1=D1eq+ΔD1 (7)
In formula：D1、D1eq、ΔD1Correspond to form of the formula (6) under Buck patterns, its equivalent control and switch control difference
For
In formula：k11And k12It is arithmetic number；
WhenWhen, ultracapacitor electric discharge, DC/DC transverters are operated in Boost patterns：
D2=D2eq+ΔD2 (10)
In formula：D2、D2eq、ΔD2Correspond to form of the formula (6) under Boost patterns, its equivalent control and switch control point
It is not
In formula：k21And k22It is arithmetic number；
Step 9：Judge whether to reach control targe, if it is, turning to step 10, otherwise turn to step 7；
Step 10：PWM：By dutycycle D the 4th in the super capacitor energy storage device is obtained after PWM
DC/DC transverter switching signals, and be sent to the 4th DC/DC transverters and be controlled.
Using having technical effect that acquired by above-mentioned technical proposal：
1. the present invention on the premise of proof load power supply quality, is utilized for the direct-current grid under unbalanced load
Ultracapacitor controls DC voltage, can simultaneously ensure the power supply quality of direct-current grid.
2. controller architecture of the invention and parameter adjustment are all fairly simple, and control accuracy is high, strong robustness.
3. super capacitor energy storage device Parameters design proposed by the present invention is simple and reliable, it is to avoid ultracapacitor
Waste of capacity, can reduce system cost.
Brief description of the drawings
The present invention is further detailed explanation with reference to the accompanying drawings and detailed description.
Fig. 1 is flow chart of the invention；
Fig. 2 is direct-current grid structure chart；
Fig. 3 is the DC voltage control system structure chart based on ultracapacitor；
Fig. 4 is the control block diagram of ultracapacitor under unbalanced load.
Specific embodiment
Embodiment 1：
As shown in figure 1, under a kind of unbalanced load direct-current grid mains ripple suppressing method, comprise the following steps：
Step 1：Set up general direct-current grid：The direct-current grid is included by wind power generating set, blower fan measurement unit
Part, AC/DC transverters cascade the wind power generation unit of composition successively, are changed by battery, measuring battery element, a DC/DC
Stream device cascades the batteries to store energy unit of composition successively, by photovoltaic array, Photovoltaic measurement element, the 2nd DC/DC transverters successively
The photovoltaic generation unit of cascade composition, DC measurement element, combining inverter, the first AC measurment element, AC network are successively
Cascade is constituted and net unit, the 3rd DC/DC transverters, DC load cascade the DC load unit of composition successively, load inverse
Become the AC load unit that device, the second AC measurment element, AC load cascade composition successively, the control system of wind power generation unit
System, the control system of batteries to store energy unit, the control system of photovoltaic generation unit；The direct-current grid is with dc bus
Center, it is wind power generation unit, batteries to store energy unit, photovoltaic generation unit, DC load unit and AC load unit, grid-connected
Unit is connected into dc bus successively by the first to the 5th DC measurement element respectively, forms radial structure, and wherein direct current is born
Dc bus is connected into by the 4th DC measurement element after carrier unit and the parallel connection of AC load unit；The wind power generation unit
Control system, the control system of batteries to store energy unit, the input of the control system of photovoltaic generation unit give a dinner for a visitor from afar respectively machine survey
The output end of amount element, measuring battery element, Photovoltaic measurement element and DC measurement element, its output end meets AC/DC respectively
Transverter, a DC/DC transverters, the input of the 2nd DC/DC transverters；
Step 2：Set up the DC voltage control system based on ultracapacitor：The DC voltage control system includes super
The control of level capacitor, super capacitor measuring cell, the 4th DC/DC transverters, the 4th DC measurement element and ultracapacitor
System is constituted；The DC voltage control system is in parallel with the AC load in direct-current grid, by the 4th DC measurement unit
Part is connected into dc bus, and the input of the control system connects the super capacitor measuring cell, DC measurement element respectively
Output end, the input of its output termination the 4th DC/DC transverter；
Step 3：Signal measurement and treatment：By voltage sensor and the electricity of current sensor measurement load-side dc bus
Pressure udc, the electric current i of the AC load is flowed to by direct-current gridr, the input current i of load inverterc, ultracapacitor
Discharge current isc, ultracapacitor terminal voltage usc；Calculate the power P that direct-current micro-grid is supplied to loadr, the power of load absorption
PL；
Step 4：Determine the reference power of DC voltage control system
Wherein：U for DC voltage square, C is DC bus capacitor, and t is the time；
Step 5：Design super capacitor energy storage device parameter：
It is super when laod unbalance degree (degree of unbalancedness is defined as percentage of the negative-sequence current divided by forward-order current) is maximum
Capacitor reference powerPeak value Pmax, ultracapacitor terminal voltage is by usc_initRise to usc_fin, charging-discharging cycle is T,
Then the capacity of ultracapacitor is
The equivalent resistance R of ultracapacitorscVery little, generally milliohm level.
Filter inductance LDCParameter can be selected according to the running status of Buck circuits, formula is
Wherein：DBuckIt is the dutycycle under Buck patterns；fsRepresent the switching frequency of DC/DC transverters；ΔiscIt is circuit
The largest ripple current of permission, is typically set to the 15% of rated current peak value.
Step 6：It is determined that control error ei
Wherein：It is the current reference value of ultracapacitor,
Step 7:Determine sliding-mode surface S：
S=ei+Ki∫eidt (5)
In formula：KiIt is arithmetic number；
Step 8:Determine the control rate D of sliding formwork control：
D=Deq+ΔD (6)
In formula：D is the dutycycle of DC/DC transverters, DeqIt is equivalent control, Δ D is switch control；
WhenWhen, ultracapacitor charges, and DC/DC transverters are operated in Buck patterns：
D1=D1eq+ΔD1 (7)
In formula：D1、D1eq、ΔD1Correspond to form of the formula (6) under Buck patterns, its equivalent control and switch control difference
For
In formula：k11And k12It is arithmetic number；
WhenWhen, ultracapacitor electric discharge, DC/DC transverters are operated in Boost patterns：
D2=D2eq+ΔD2 (10)
In formula：D2、D2eq、ΔD2Correspond to form of the formula (6) under Boost patterns, its equivalent control and switch control point
It is not
In formula：k21And k22It is arithmetic number；
Step 9：Judge whether to reach control targe, if it is, turning to step 10, otherwise turn to step 7；
Step 10：PWM：By dutycycle D the 4th in the super capacitor energy storage device is obtained after PWM
DC/DC transverter switching signals, and be sent to the 4th DC/DC transverters and be controlled.
The present embodiment direct voltage reference value is typically set to the connected dc bus rated voltage of AC load, i.e. in Fig. 2
The rated voltage of node 5, concrete numerical value is relevant with bearing power.In super capacitor energy storage device, super capacitor capacity 5.9mF,
Equivalent resistance 2.1m Ω, filter inductance 0.2mH.
The direct-current grid is mainly made up of four parts：Including the distribution including wind power generating set and photovoltaic generation
Generator unit, accesses dc bus by AC/DC and DC/DC transverters respectively, is responsible for direct-current grid and provides electric energy；Electric power storage
Pond energy-storage units, dc bus is accessed by DC/DC transverters, is responsible for maintenance system internal power balance, and under island mode
Stable DC voltage；The existing DC load of load type of direct-current grid has AC load again, respectively by DC/DC and DC/
AC transverters access dc bus；Direct-current grid is incorporated to exchange major network by DC/AC transverters.
It is DC voltage ripple under suppression unbalanced load, the present invention increases ultracapacitor and accesses the outlet of load current-change device
Dc bus on, as shown in figure 3, simplified model of the present invention using ultracapacitor, and by non-isolation type Buck-
The two-way DC/DC transverters of Boost access dc bus.C is DC bus capacitor, u in figuredcIt is capacitance voltage, PrIt is direct-current micro-grid
It is supplied to the power of load, PLIt is the power of load absorption；PscIt is the power that ultracapacitor absorbs, S1、S2Represent switching tube,
LDCIt is inductance, Csc、RscThe equivalent capacity and equivalent resistance of ultracapacitor simplified model, i are represented respectivelyscIt is ultracapacitor
Charging current, uscIt is ultracapacitor terminal voltage, ucIt is the terminal voltage of ultracapacitor equivalent capacity.Present invention is generally directed to
The control of DC/DC transverters, the i.e. DC voltage control system based on sliding mode controller.
The Mathematical Modeling of DC bus capacitor is：
The then reference power of DC voltage control systemFor：
Wherein, u is DC voltage udcSquare.
Establish the control targe of sliding mode controller；The major control target of DC/DC transverters is by controlling super capacitor
The electric current i of devicescTo suppress DC voltage ripple, and with good dynamic response performance；It is thus determined that following tracking error：
In formula：It is the current reference value of ultracapacitor,
Determine sliding-mode surface, the present invention is using Integral Sliding Mode face：
S=ei+Ki∫eidt (16)
In formula：The static error for being introduced for elimination system of integral term, KiIt is arithmetic number；
Determine control rate；The present invention uses following control rate structure：
D=Deq+ΔD (17)
In formula：DeqIt is equivalent control, the effect of equivalent control is system is moved along sliding-mode surface in the ideal situation, equivalent
Control can accelerate the response speed of system, reduce the static error of system.Δ D for switch control, switch control can make be
System reaches sliding-mode surface from arbitrary original state within the limited time.Control targe of the invention, the control rate is divided into
Two kinds of situations：
WhenWhen, ultracapacitor charges, and DC/DC transverters are operated in Buck patterns：
D1=D1eq+ΔD1 (18)
In formula：D1、D1eq、ΔD1Correspond to form of the control rate under Buck patterns, the order of its equivalent controlObtain
The present invention is using the super-twisting algorithm design switch control in sliding formwork control；Design rule according to super-twisting algorithm
Then, switch control design case is as follows：
In formula：k11And k12It is arithmetic number；
WhenWhen, ultracapacitor electric discharge, DC/DC transverters are operated in Boost patterns：
D2=D2eq+ΔD2 (21)
In formula：D2、D2eq、ΔD2Form of the control rate under Boost patterns is corresponded to, its equivalent control can be similarly obtained
System and switch control are respectively
In formula：k21And k22It is arithmetic number；
To suppress DC voltage ripple as the control strategy of control targe during establishment laod unbalance；Due to sliding formwork control energy
It is enough that of ac is controlled, therefore, as long as the reference value for setting controller is DC quantity, you can realize to DC voltage and nothing
Static difference is adjusted, that is, the two frequencys multiplication pulsation for eliminating DC voltage is dynamic；The stabilization of DC voltage is can be seen that by DC side Mathematical Modeling
Substantially reflect the power P that direct-current micro-grid is supplied to loadr, the power P of load absorptionLThe power absorbed with ultracapacitor
PscThe balance of three；As long as control Psc2 harmonics of compensation (14) the equal sign right side power with, you can effectively suppress straight
Stream mains ripple；
Fig. 4 gives the control block diagram of the control strategy.
Claims (2)
1. a kind of mains ripple suppressing method for direct-current grid under unbalanced load, it is characterised in that：Including following step
Suddenly：
Step 1：Set up general direct-current grid：The direct-current grid include by wind power generating set, blower fan measuring cell,
AC/DC transverters cascade the wind power generation unit of composition successively, by battery, measuring battery element, a DC/DC transverters
The batteries to store energy unit of composition is cascaded successively, is cascaded successively by photovoltaic array, Photovoltaic measurement element, the 2nd DC/DC transverters
The photovoltaic generation unit of composition, DC measurement element, combining inverter, the first AC measurment element, AC network are cascaded successively
Composition and net unit, the 3rd DC/DC transverters, DC load cascade the DC load unit of composition successively, load inverter,
Second AC measurment element, AC load cascade the AC load unit of composition successively, and the control system of wind power generation unit stores
The control system of battery energy storage unit, the control system of photovoltaic generation unit；The direct-current grid centered on dc bus,
Wind power generation unit, batteries to store energy unit, photovoltaic generation unit, DC load unit and AC load unit and net unit
Dc bus is connected into by the first to the 5th DC measurement element successively respectively, radial structure, wherein DC load list is formed
Dc bus is connected into by the 4th DC measurement element after unit and the parallel connection of AC load unit；The control of the wind power generation unit
System, the control system of batteries to store energy unit, the input of the control system of photovoltaic generation unit give a dinner for a visitor from afar respectively machine measurement unit
The output end of part, measuring battery element, Photovoltaic measurement element and DC measurement element, its output end connects the AC/DC changes of current respectively
Device, a DC/DC transverters, the input of the 2nd DC/DC transverters；
Step 2：Foundation is based on
DC voltage control system：The DC voltage control system includes ultracapacitor, super capacitor measuring cell, the
The control system composition of four DC/DC transverters, the 4th DC measurement element and ultracapacitor；The DC voltage control system
It is in parallel with the AC load in direct-current grid, dc bus is connected into by the 4th DC measurement element, the control system
Input connects the super capacitor measuring cell, the output end of DC measurement element respectively, its output termination the 4th DC/DC
The input of transverter；
Step 3：Signal measurement and treatment：By voltage sensor and the voltage of current sensor measurement load-side dc bus
udc, the electric current i of the AC load is flowed to by direct-current gridr, the input current i of load inverterc, ultracapacitor puts
Electric current isc, ultracapacitor terminal voltage usc；Calculate the power P that direct-current micro-grid is supplied to loadr, the power P of load absorptionL；
Step 4：Determine the reference power of DC voltage control system
Wherein：U for DC voltage square, C is DC bus capacitor, and t is the time；
Step 5：Design the parameter of super capacitor energy storage device：
The capacity of ultracapacitor is：
In formula, PmaxIt is reference powerPeak value；Charging-discharging cycle is T, and charging process is ultracapacitor terminal voltage in T/2
uscBy usc_initRise to usc_fin,
Filter inductance LDCFor：
Wherein：DBuckIt is the dutycycle under Buck patterns；fsRepresent the switching frequency of DC/DC transverters；ΔiscIt is circuit permission
Largest ripple current；
Step 6：It is determined that control error ei
Wherein：It is the current reference value of ultracapacitor,
Step 7:Determine sliding-mode surface S：
S=ei+Ki∫eidt (5)
In formula：KiIt is arithmetic number；
Step 8:Determine the control rate D of sliding formwork control：
D=Deq+ΔD (6)
In formula：D is the dutycycle of DC/DC transverters, DeqIt is equivalent control, Δ D is switch control；
WhenWhen, ultracapacitor charges, and DC/DC transverters are operated in Buck patterns：
D1=D1eq+ΔD1 (7)
In formula：D1、D1eq、ΔD1Correspond to form of the formula (6) under Buck patterns；
WhenWhen, ultracapacitor electric discharge, DC/DC transverters are operated in Boost patterns：
D2=D2eq+ΔD2 (8)
In formula：D2、D2eq、ΔD2Correspond to form of the formula (6) under Boost patterns；
Step 9：Judge whether to reach control targe, if it is, turning to step 10, otherwise turn to step 7；
Step 10：PWM：By dutycycle D in the super capacitor energy storage device is obtained after PWM the 4th DC/DC
Transverter switching signal, and be sent to the 4th DC/DC transverters and be controlled.
2. according to claim 1, it is characterised in that：
Equivalent control D in the step 81eqFor：
Switch control Δ D1For：
In formula：k11And k12It is arithmetic number；
Equivalent control D2eqFor：
Switch control Δ D2For：
In formula：k21And k22It is arithmetic number.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107154621A (en) * | 2017-06-05 | 2017-09-12 | 华北电力大学（保定） | The virtual synchronous generator control method of direct-current grid energy-storage units DC DC transverters |
| CN111371144A (en) * | 2020-03-25 | 2020-07-03 | 深圳威迈斯新能源股份有限公司 | Control method for reducing capacitance value of capacitor of charging equipment of new energy electric automobile |
| CN112217194A (en) * | 2019-07-11 | 2021-01-12 | 华北电力大学（保定） | Direct-current voltage deviation suppression strategy based on feedforward current control of disturbance observer |
| CN112217219A (en) * | 2019-07-11 | 2021-01-12 | 华北电力大学（保定） | Direct-current transient power quality control and recovery strategy based on super capacitor |
| CN112510814A (en) * | 2020-11-25 | 2021-03-16 | 漳州科华技术有限责任公司 | UPS power supply control method and device and terminal equipment |
| CN112737344A (en) * | 2020-12-29 | 2021-04-30 | 联合汽车电子有限公司 | Battery charging circuit |
| CN113517724A (en) * | 2021-04-09 | 2021-10-19 | 国网山西省电力公司电力科学研究院 | Method for suppressing voltage ripple on direct current side of alternating current-direct current hybrid micro-grid |
| CN115693632A (en) * | 2022-09-07 | 2023-02-03 | 广东工业大学 | Control method for direct-current micro-grid power oscillation suppression device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104659804A (en) * | 2013-11-20 | 2015-05-27 | 沈阳工业大学 | Micro power grid with hybrid energy storage, and control method of micro power grid |
-
2017
- 2017-03-02 CN CN201710120041.8A patent/CN106786485B/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104659804A (en) * | 2013-11-20 | 2015-05-27 | 沈阳工业大学 | Micro power grid with hybrid energy storage, and control method of micro power grid |
Non-Patent Citations (2)
| Title |
|---|
| XIAORONG ZHU ETC: "Control strategy of DC Microgrid Under Unbalanced Grid Voltage", 《2016IEEE 8TH INTERNATIONAL POWER ELECTRONICS AND MOTION CONTROL CONFERENCE》 * |
| 朱晓荣等: "不平衡电网电压下光伏并网逆变器滑模直接电压/功率控制策略", 《电力系统保护与控制》 * |
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