Summary of the invention
The purpose of the present invention is to provide a kind of for stabilizing the control equipment of the energy-storage system of wind power output power, can
While to energy-storage system protection, maintain grid-connected power in grid-connected target value or so.
It is set to solve the above problems, the present invention provides a kind of control for stabilizing the energy-storage system of wind power output power
It is standby, including wind power plant and mixed energy storage system, wherein
The mixing is formed by lithium battery, supercapacitor, biphase rectification/inverter and the first, second DC/DC current transformer
Energy-storage system, the low-pressure side of the first DC/DC current transformer connect lithium battery, the high-pressure side connection of the first DC/DC current transformer the
The low-pressure side of two DC/DC current transformers, the first DC/DC current transformer is simultaneously in parallel with the supercapacitor, the 2nd DC/DC
Current transformer high-pressure side is connected to biphase rectification/inverter DC side, and biphase rectification/inverter exchange side is connected in parallel on wind power plant and goes out
The low-pass first order filter of mouth;
Charging-discharging controller, respectively with power grid, the low-pass first order filter, the first DC/DC current transformer and described second
The connection of DC/DC current transformer;
It is connected to the sliding average algorithm device of lithium battery and supercapacitor input side, when mixed energy storage system is run, institute
Controller is stated using wind power output power and grid-connected reference power as foundation, the charging-discharging controller calculates low with fuzzy control
Pass filtering time constant, Power Output for Wind Power Field are passed through after the low-pass first order filter, and sliding average algorithm device is passed through
Control target is stabilized, and passes to DC/DC current transformer, and then control lithium battery and supercapacitor carry out power and handle up, most
The power after stabilizing is sent into power grid afterwards.
Further, in the control equipment of the above-mentioned energy-storage system for stabilizing wind power output power, the charge and discharge
Controller carries out the charge and discharge stabilizing control, that is, stabilizing to wind power output power based on the first-order low-pass wave algorithm for becoming time constant
Electrical power are as follows:
In formula: Pwind(t) preceding power is filtered for t moment wind power;Pwind(t- Δ t) is last moment wind power
The power after filtering;τ is time constant filter;
The time constant of low-pass first order filter is determined using fuzzy control, defines a new variable: wind-powered electricity generation output
Power swing degree P0(t), expression formula are as follows:
In formula: PrefIt (t) is grid-connected reference power, as the input x (t) of fuzzy control.
Further, in the control equipment of the above-mentioned energy-storage system for stabilizing wind power output power, the charge and discharge
Wind power output power undulate quantity is divided into five grades by controller, selects corresponding low-pass filtering by fuzzy control output result
Time constant.
Further, in the control equipment of the above-mentioned energy-storage system for stabilizing wind power output power, it is situated between according to energy storage
Matter residual capacity situation provides corresponding power distribution strategies are as follows: power density is big, the supercapacitor that has extended cycle life is preferential
Charge and discharge;It when lithium battery residual capacity is enough, is used for power and stabilizes, set lithium battery, supercapacitor residual capacity
Soc-bat、Soc-cap。
Further, in the control equipment of the above-mentioned energy-storage system for stabilizing wind power output power, the power point
With strategy are as follows:
Work as PHESS(t) > 0 when, i.e., mixed energy storage system discharges, and defines different electric discharges according to supercapacitor SOC variation
State:
Discharge condition 1:Soc-cap> 0.1, supercapacitor preferential discharge, lithium battery is failure to actuate;
Discharge condition 2:Soc-cap< 0.1, Soc-bat> 0.4, lithium battery electric discharge, supercapacitor does not work;
Discharge condition 3:Soc-bat< 0.4, then it does not work;
Work as PHESS(t)≤0 when, i.e., mixed energy storage system charges.Different charging shapes is defined according to lithium battery SOC variation
State:
Charged state 1:Soc-bat> 0.8, supercapacitor charging;
Charged state 2:Soc-bat< 0.8, lithium battery charging.
Further, in the control equipment of the above-mentioned energy-storage system for stabilizing wind power output power, the sliding is flat
Mean algorithm device is used for:
N time series PHESS(t+n Δ t) calculates the average value of multiple continuous m sequences, wherein continuous m sequence
First item is the first item P of original n sequenceHESS(t) to m PHESS(the sum of t+m Δ t) is divided by m;The of continuous m sequences
Binomial PHESS(t+ Δ t) is the Section 2 of original n sequence to m+1 PHESS(the sum of t+ (m+1) Δ t) is divided by m;And so on,
The sliding average algorithm expression formula of lithium battery and supercapacitor are as follows:
In formula: Preal-bat(t)、Preal-cap(t) be respectively lithium battery of the t moment after sliding average algorithm process,
Supercapacitor power;Pbat(t)、PcapIt (t) is lithium battery, super capacitor of the t moment without sliding average algorithm process
Device power.
Further, in the control equipment of the above-mentioned energy-storage system for stabilizing wind power output power, the charge and discharge
Controller uses the two-way DC/DC chopper controller of Buck-Boost, and uses power outer ring, the double-closed-loop control of current inner loop
Mode.
Further, in the control equipment of the above-mentioned energy-storage system for stabilizing wind power output power, outside the power
Ring is used to maintain the stabilization of output power, and current inner loop given value is obtained by power divided by DC voltage, then given value of current
Value and detection electric current do deviation, by PI link, obtain modulation voltage, and modulation voltage passes through SPWM, obtain control signal, described
Control signal is for controlling two-way DC/DC chopper, to control lithium battery power output.
Compared with prior art, the present invention is in the case where grid-connected reference power is given, with fuzzy control principle, according to
Wind power output power and the departure degree of grid-connected reference value select low-pass filtering time constant, calculate simple, holding output power
Follow regulation goal value;Control strategy with supercapacitor priority task principle divides mixed energy storage system power
Match;By the way that sliding average value-based algorithm is connected to mixed energy storage system input side, for stabilizing spike and being fluctuated toward the wind-powered electricity generation of renaturation,
With sliding average principle to stabilize target carry out it is secondary stabilize, for stabilize spike and toward renaturation wind power fluctuate, prolong
The long energy-storage system service life;Energy-storage system is controlled by the way that quantity of power is changed into the magnitude of current, may be implemented what its power was handled up
Quickly, it accurately controls, improves dynamic performance.By implementing above-mentioned power distribution strategies, make mixed energy storage system can be
Under conditions permit, preferential supercapacitor work, can effectively stabilize wind power output power fluctuation and lithium battery is excessive
Charge and discharge task, extend cycle life, the cost of mixed energy storage system is effectively reduced.While to energy-storage system protection, dimension
Grid-connected power is held in grid-connected target value or so.Its simulation result shows: proposed by the invention to stabilize for wind power output power
Mixed energy storage system control strategy compared with Traditional control strategy, avoid energy-storage system and excessively regulate and control, grid-connected power maintains
In grid-connected target value or so.
Specific embodiment
In order to make the foregoing objectives, features and advantages of the present invention clearer and more comprehensible, with reference to the accompanying drawing and specific real
Applying mode, the present invention is described in further detail.
As shown in Figure 1, the present invention provide it is a kind of for stabilizing the control equipment of the energy-storage system of wind power output power, including
Wind power plant and mixed energy storage system, wherein
Described in being made of lithium battery 3, supercapacitor 4, biphase rectification/inverter 5 and the first, second DC/DC current transformer
Mixed energy storage system, the low-pressure side of the first DC/DC current transformer 1 connect lithium battery, and the high-pressure side of the first DC/DC current transformer connects
The low-pressure side of the 2nd DC/DC current transformer 2 is connect, the first DC/DC current transformer is simultaneously in parallel with the supercapacitor, and described second
2 high-pressure side of DC/DC current transformer is connected to biphase rectification/inverter DC side, and biphase rectification/inverter exchange side is connected in parallel on wind
The low-pass first order filter 7 that electric field 6 exports;
Charging-discharging controller 8, respectively with power grid 10, the low-pass first order filter, the first DC/DC current transformer and described
The connection of two DC/DC current transformers;
It is connected to the sliding average algorithm device 9 of 4 input side of lithium battery 3 and supercapacitor, when mixed energy storage system is run,
For the controller using wind power output power and grid-connected reference power as foundation, charging-discharging controller calculates low pass with fuzzy control
Time constant filter, Power Output for Wind Power Field are passed through after the low-pass first order filter, flat by sliding average algorithm device
Suppression control target, and DC/DC current transformer is passed to, and then control lithium battery and supercapacitor carry out power and handle up, and realize
Wind power fluctuation is stabilized, and the power after stabilizing finally is sent into power grid." power buffering is served as with sliding average value-based algorithm
Device " is connected to lithium battery and supercapacitor input side.Realize spike stabilize and toward renaturation wind power fluctuate.By wind-powered electricity generation function
Rate fluctuation limits in a certain range, and mixed energy storage system is realized in the excessive regulation for avoiding energy-storage system from fluctuating wind power
It reduces charge and discharge number and extends the purpose in service life.The present invention is avoided energy-storage system and is excessively adjusted by sliding average value-based algorithm
Control, is conducive to energy-storage system life-time dilatation;Two DC/DC chopper controllers are carried out by the way that quantity of power is converted into the magnitude of current
Control, it can be achieved that lithium battery and supercapacitor charge and discharge task it is quick, accurately control, ensure that the smooth of control strategy
It realizes.
Preferably, target, that is, mixed energy storage system gross capability is controlled, charging-discharging controller of the present invention is based on becoming the time
The first-order low-pass wave algorithm of constant carries out the charge-discharge electric power stabilizing control, that is, stabilizing to wind power output power are as follows:
In formula: Pwind(t) preceding power is filtered for t moment wind power;Pwind(t- Δ t) is last moment wind power
The power after filtering;τ is time constant filter;
In order to make the more stable output of power, the present invention determines that the time of low-pass first order filter is normal using fuzzy control
Number.Define a new variable: wind power output power fluctuation degree P0(t), expression formula are as follows:
In formula: Pref(t) be grid-connected reference power, as the input x (t) of fuzzy control, input subordinating degree function and
Export subordinating degree function difference as shown in figures 2 a and 2b, Fuzzy control system input/output curved surface is as shown in Figure 3.
Preferably, become the Controlling principle of time constant: according to wind power output power fluctuation degree P0(t) size, segmentation are adjusted
Whole suitable low-pass filtering time constant, i.e. dynamic regulation mixed energy storage system charge-discharge electric power, realization stabilize rear power more
Stable output.
Preferably, wind power output power undulate quantity is divided into five grades by charging-discharging controller of the present invention, by fuzzy
Control output result selects corresponding low-pass filtering time constant.Wind power output power undulate quantity is divided into five grade controls
As shown in figure 4, in Practical Project utilization, segment level quantity can be adjusted process by practical wind regime.For differently
The wind power plant for managing position, can analyze its history generated output curve, acquire main vibration frequency range, big according to range
The quantity of small setting low-pass filtering time constant;The specific selection of time constant can be according to the concrete property of mixed energy storage system
With the requirement to grid-connected power swing rate, thus meet the filter of design under different wind regime grid-connected stability bandwidth without departing from country
Regulation.
Preferably, corresponding power distribution strategies, power distribution principle are provided according to energy-accumulating medium residual capacity situation are as follows:
The preferential charge and discharge of supercapacitor that power density is big, has extended cycle life;When lithium battery residual capacity is enough, it to be used for power
It stabilizes, sets lithium battery, supercapacitor residual capacity Soc-bat、Soc-cap。
Preferably, the process of power distribution strategies is as shown in Figure 5:
Work as PHESS(t) > 0 when, i.e., mixed energy storage system discharges, and defines different electric discharges according to supercapacitor SOC variation
State:
Discharge condition 1:Soc-cap> 0.1, supercapacitor preferential discharge, lithium battery is failure to actuate;
Discharge condition 2:Soc-cap< 0.1, Soc-bat> 0.4, lithium battery electric discharge, supercapacitor does not work;
Discharge condition 3:Soc-bat< 0.4, then it does not work;
Work as PHESS(t)≤0 when, i.e., mixed energy storage system charges.Different charging shapes is defined according to lithium battery SOC variation
State:
Charged state 1:Soc-bat> 0.8, supercapacitor charging;
Charged state 2:Soc-bat< 0.8, lithium battery charging.By implementing above-mentioned power distribution strategies, make hybrid energy-storing system
System can be under conditions permit, preferential supercapacitor work.Wind power output power fluctuation and lithium can effectively be stabilized
The excessive charge and discharge task of battery extends cycle life.The cost of mixed energy storage system is effectively reduced.
Preferably, the sliding average algorithm device is used for:
N time series PHESS(t+n Δ t) calculates the average value of multiple continuous m sequences, wherein continuous m sequence
First item is the first item P of original n sequenceHESS(t) to m PHESS(the sum of t+m Δ t) is divided by m;The of continuous m sequences
Binomial PHESS(t+ Δ t) is the Section 2 of original n sequence to m+1 PHESS(the sum of t+ (m+1) Δ t) is divided by m;And so on,
The sliding average algorithm expression formula of lithium battery and supercapacitor are as follows:
In formula: Preal-bat(t)、Preal-cap(t) be respectively lithium battery of the t moment after sliding average algorithm process,
Supercapacitor power;Pbat(t)、PcapIt (t) is lithium battery, super capacitor of the t moment without sliding average algorithm process
Device power.
Preferably, the charging-discharging controller uses the two-way DC/DC chopper controller of Buck-Boost, to improve system
Dynamic property guarantees that the stabilization of lithium battery and supercapacitor output power, control system of the invention use power outer ring, electricity
The double-closed-loop control mode of stream inner ring optimizes, and in such a way that quantity of power is converted into the magnitude of current, improves system response speed
Degree.
Preferably, by taking lithium battery controller as an example, as shown in fig. 6, the power outer ring is for maintaining the steady of output power
Fixed, current inner loop given value is obtained by power divided by DC voltage, and then given value of current value and detection electric current do deviation, is passed through
PI link obtains modulation voltage, and modulation voltage passes through SPWM, obtains control signal, the control signal is for controlling two-way DC/
DC chopper, to control lithium battery power output.
It is simulation analysis of the invention as follows:
1. parameter setting
Structure according to Fig. 1 carries out simulating, verifying under Matlab/Simulink environment.Simulation parameter is provided that
Sampling interval T=1 × 10-5S, lithium battery group 250V, 10Ah, initial SOC=70%;Capacity of super capacitor 10F, pressure resistance
400V, initial voltage 400V;Filter inductance 10mH in DC/DC (1), DC/DC (2);PI controller parameter: Kp=2, Ki=10;It is sliding
Dynamic average algorithm m=5.
2. the validation verification of mixed energy storage system control strategy and its system
The present invention sets energy storage system discharges power and is positive, and charge power is negative, and wind power is positive.Grid-connected reference power
PrefIt (t) is 12KW, vibration frequency 50HZ, lithium battery is by 50A constant current charge-discharge.Simulation objectives: verifying control strategy of the present invention
Validity realizes stabilizing for power swing;Verifying mixed energy storage system is under the control system that designs of the present invention, lithium battery and super
The power of grade capacitor is quick, accurately controls.
The verifying that 2.1 power swings are stabilized
Fig. 7 is the 50HZ vibration frequency signal generator of setting.Using 0.2s as a cycle, the letter of different amplitudes is exported
Number, realize the effect of simulation wind power fluctuation.In Fig. 8, Pwind(t) it indicates to stabilize preceding wind power output power (- 2~15KW);
PHESS is mixed energy storage system charge-discharge electric power;Pout is to stabilize rear power.Work as Pwind(t) it is greater than Pref(t), energy-storage system fills
Electricity absorbs surplus power;Work as Pwind(t) it is less than Pref(t), energy storage system discharges compensate insufficient power.I.e. wind is stabilized in control
Electrical power fluctuates size, and output power is kept to follow regulation goal value.Power P out after stabilizing as the result is shown is maintained essentially in
12KW。
Grid-connected power is determined according to the variation of energy-storage system state-of-charge, avoids the overshoot and over-discharge of energy-storage system.Its
Major advantage is the protection to energy-storage system, but grid-connected power is unable to maintain that in grid-connected target value.Control proposed by the present invention
Strategy (is realized) while protecting energy-storage system by power distribution strategies, can maintain grid-connected target value as far as possible.Figure
10 be wind power output power Pwind(t), according to energy-storage system state-of-charge determine grid-connected power P 'out11 and it is of the invention and
Net power Pout12 comparison.It is seen that due to the limitation of energy-storage system residual capacity, P 'outIt not can guarantee and maintain
12KW, and PoutWaveform maintains essentially in 12KW or so.
Fig. 9 is the comparison that conventional filter and change time constant filter power are stabilized.It is obscured shown in a, 2b according to fig. 2
Subordinating degree function is controlled, operational process of the analogue system between 0~0.8s is analyzed.Deviateed according to wind power output power grid-connected
The degree of reference power exports low-pass filtering time constant by fuzzy control.0.26s~0.305s can be seen that from Fig. 9
When wind power output power is near 12KW, constant low-pass filtering of fixing time and become time constant low-pass filtering to stabilize effect several
It is identical;When the change rate of wind power output power fluctuation is larger, become time constant low-pass first order filter stabilizes effect more
It is good.The advantage is that can " adaptation to local conditions " set and different stabilize mesh according to different wind power output power adjustment time constants
Mark.
The verifying of 2.2 power distributions
It is allocated in mixed energy storage system using the part that fuzzy control theory will exceed grid-connected reference value, it can be effective
Wind power fluctuation is stabilized, the advantage is that and avoid the out-of-limit phenomenon of energy-storage system state, realizes the purpose of protection energy-storage system,
But this strategy is to cause dynamic performance poor directly controlling for power, and spike and past renaturation wind power fluctuate meeting
The excessive regulation for influencing energy-storage system, causes the life consumption of battery energy storage.The present invention is based on the controllers of optimization design to protect
While protecting energy-storage system, the excessive regulation of system is avoided.
By the double-closed-loop control (power outer ring, current inner loop) in DC/DC (1) and DC/DC (2), realize to energy storage
The quick of system, exact power control.Power is directly controlled P ' ' by Figure 11outWith double-closed-loop control PoutIt compares, finds P
‘’outDue to directly controlling for power, the accumulation of power deviation is caused.And dynamic property is poor, and power curve has apparent stagnant
Afterwards.
In conjunction with Fig. 8, from lithium battery in Figure 12 and supercapacitor charge-discharge electric power curve: supercapacitor is preferentially filled
Electric discharge, only when supercapacitor residual capacity deficiency, the remaining control target of lithium battery compensation extends the energy-storage system service life
Meanwhile guaranteeing that output power follows regulation goal value;From the operational process concrete analysis between 0~0.1s: energy-storage system
Electric discharge, since supercapacitor residual capacity is greater than 0.1, supercapacitor preferential discharge, lithium battery is failure to actuate.And due to 0s
Wind speed mutation causes wind power output power fluctuation excessive, to protect lithium battery, maintains last moment charge-discharge electric power constant, by
Supercapacitor undertakes entire wind-powered electricity generation undulate quantity, and lithium battery is avoided to be impacted.Other times Duan Jieke carries out similar analysis.
Known to Figure 13 comparison: will cause the excessive tune of traditional energy-storage system due to spike and toward the fluctuation of renaturation wind power
Control;And be connected to lithium battery and supercapacitor input side has sliding average value-based algorithm 12 compared to fricton-tight average algorithm 11
Such power swing can be stabilized to a certain extent.Impact of the power swing to mixed energy storage system is reduced, energy-storage system is extended
Service life.
As the above analysis: the control strategy is relative to the control changed using time constant with energy-storage system residual capacity
System strategy has certain advantage, under the premise of protecting energy-storage system, can preferably maintain grid-connected power in grid-connected reference value, have
Conducive to the stabilization of power grids.
In conclusion the present invention is in the case where grid-connected reference power is given, it is defeated according to wind-powered electricity generation with fuzzy control principle
Power and the departure degree of grid-connected reference value select low-pass filtering time constant out, calculate simple, holding output power and follow tune
Spend target value;Mixed energy storage system power is allocated with the control strategy of supercapacitor priority task principle;Pass through
Sliding average value-based algorithm is connected to mixed energy storage system input side, for stabilizing spike and fluctuating toward the wind-powered electricity generation of renaturation, with cunning
Dynamic average value principle to stabilize target carry out it is secondary stabilize, for stabilizing spike and fluctuating toward renaturation wind power, extend energy storage
Lifetime of system;Energy-storage system is controlled by the way that quantity of power is changed into the magnitude of current, may be implemented its power handle up it is quick, quasi-
Really control improves dynamic performance.By implementing above-mentioned power distribution strategies, make mixed energy storage system can be in conditions permit
Under, preferential supercapacitor work can effectively stabilize the charge and discharge that wind power output power fluctuates and lithium battery is excessive
Task extends cycle life, the cost of mixed energy storage system is effectively reduced.While to energy-storage system protection, grid-connected function is maintained
Rate is in grid-connected target value or so.Its simulation result shows: the mixing storage stabilized for wind power output power proposed by the invention
Energy system control strategy avoids energy-storage system and excessively regulates and controls compared with Traditional control strategy, and grid-connected power maintains and mesh
Scale value or so.
Each embodiment in this specification is described in a progressive manner, the highlights of each of the examples are with other
The difference of embodiment, the same or similar parts in each embodiment may refer to each other.
Professional further appreciates that, in conjunction with disclosed in this invention each exemplary list for describing of embodiment
Member and algorithm steps, can be realized with electronic hardware, computer software, or a combination of the two, in order to clearly demonstrate hardware
With the interchangeability of software, each exemplary composition and step are generally described according to function in the above description.This
A little functions are implemented in hardware or software actually, the specific application and design constraint depending on technical solution.Specially
Industry technical staff can use different methods to achieve the described function each specific application, but this realization is not
It is considered as beyond the scope of this invention.
Obviously, those skilled in the art can carry out various modification and variations without departing from spirit of the invention to invention
And range.If in this way, these modifications and changes of the present invention belong to the claims in the present invention and its equivalent technologies range it
Interior, then the invention is also intended to include including these modification and variations.