CN111030170A - Energy coordination management method and system for optical storage type virtual synchronous machine - Google Patents
Energy coordination management method and system for optical storage type virtual synchronous machine Download PDFInfo
- Publication number
- CN111030170A CN111030170A CN201911261554.6A CN201911261554A CN111030170A CN 111030170 A CN111030170 A CN 111030170A CN 201911261554 A CN201911261554 A CN 201911261554A CN 111030170 A CN111030170 A CN 111030170A
- Authority
- CN
- China
- Prior art keywords
- energy storage
- synchronous machine
- virtual synchronous
- storage device
- soc
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000001360 synchronised effect Effects 0.000 title claims abstract description 117
- 230000003287 optical effect Effects 0.000 title claims abstract description 53
- 238000007726 management method Methods 0.000 title claims abstract description 17
- 238000004146 energy storage Methods 0.000 claims abstract description 122
- 238000011217 control strategy Methods 0.000 claims abstract description 14
- 238000000034 method Methods 0.000 claims abstract description 13
- 230000008859 change Effects 0.000 claims description 4
- 238000013016 damping Methods 0.000 claims description 4
- 230000005611 electricity Effects 0.000 claims description 3
- 230000008569 process Effects 0.000 abstract description 4
- 238000010248 power generation Methods 0.000 description 13
- 238000010586 diagram Methods 0.000 description 11
- 238000004088 simulation Methods 0.000 description 3
- 230000033228 biological regulation Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000002457 bidirectional effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Images
Classifications
-
- 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
- H02J3/28—Arrangements for balancing of the load in a network by storage of energy
- H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
-
- 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
- Y02E70/00—Other energy conversion or management systems reducing GHG emissions
- Y02E70/30—Systems combining energy storage with energy generation of non-fossil origin
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The embodiment of the invention discloses a light storage type virtual synchronous machine energy coordination management method, which comprises the following steps: the photovoltaic power supply, the energy storage device and the light storage type virtual synchronous machine on the upper layer are subjected to a working mode selection strategy; the power output control strategy of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine on the lower layer; the invention also comprises a system, which dynamically adjusts the output characteristics of the photovoltaic, the energy storage and the VSG by analyzing the power output requirement of the VSG, the output condition of the photovoltaic power supply and the SOC state of the energy storage device, so that the photovoltaic, the energy storage and the virtual synchronous machine all participate in the power balance process, the dependence of the VSG on the energy storage capacity is effectively improved, the SOC of the energy storage device is asymmetrically controlled, the SOC of the energy storage can be maintained at a higher level, the VSG always has enough spare capacity to ensure the characteristics of the virtual synchronous machine, the inertia of the virtual synchronous machine is preferentially ensured, and the optical storage type synchronous generator cannot completely lose functions due to insufficient energy storage capacity.
Description
Technical Field
The embodiment of the invention relates to the technical field of distributed photovoltaic grid-connected power generation, in particular to a light storage type virtual synchronous machine energy coordination management method and system.
Background
In order to deal with energy crisis and environmental pressure, distributed power generation technology is receiving more and more extensive attention, and photovoltaic power generation is greatly developed in a power grid as an important new energy. The inertia and damping of the traditional synchronous generator are lacked in the distributed power generation system, and the grid connection of the distributed power sources enables the power system to be more easily affected by power fluctuation and system faults. This problem becomes increasingly non-negligible as the permeability of distributed power generation in the system increases.
The Virtual Synchronous Generator (VSG) realizes the physical and mathematical equivalence of the distributed power generation system with the synchronous generator by simulating the rotor equation of the synchronous generator, has the capabilities of smooth power output, peak regulation, frequency modulation and the like, and becomes a power grid-friendly distributed power supply. In some cases, researchers pay attention to control strategies of inverters and virtual characteristic research of power supplies, and simulate a direct current side as a power source with constant voltage and infinite capacity. However, the output power of the photovoltaic power supply has intermittency and volatility, and the virtual synchronous machine needs to adjust the output power according to the frequency characteristic of the power grid, so that a certain active power difference exists between the photovoltaic output power and the output power of the virtual synchronous machine, and the actual application of the virtual synchronous machine involves a complex energy management problem.
The existing mainly adopted solution is that a photovoltaic power generation system is improved to output power in a certain proportion of the maximum power point, and the problem of unbalanced active power is solved by means of standby power generation capacity, but the strategy reduces the utilization rate of photovoltaic and improves the operation cost; and the other type of the virtual synchronous machine makes up the power difference of the virtual synchronous machine by configuring an energy storage device on a direct current bus of the power generation unit, so that the inertia and the frequency modulation capability of the virtual synchronous machine are realized. However, the supply and demand balance of power is only coordinated through the energy storage device, and the requirement on the capacity of the energy storage device is high.
Disclosure of Invention
Therefore, the embodiment of the invention provides an energy coordination management method and system for a light storage type virtual synchronous machine, which solve the problem of dependence of a VSG on energy storage capacity in the prior art by realizing coordination control of a photovoltaic power supply, energy storage equipment and an inverter.
In order to achieve the above object, an embodiment of the present invention provides the following:
a light storage type virtual synchronous machine energy coordination management method comprises the following steps:
selecting a working mode according to a working mode selection strategy of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine on the upper layer;
and carrying out power output control according to power output control strategies of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine at the lower layer.
As a preferred scheme of the present invention, the selection strategy dynamically adjusts the output of the photovoltaic power supply and the virtual characteristics of the optical storage type virtual synchronous machine by analyzing the power output requirement of the optical storage type virtual synchronous machine, the output condition of the photovoltaic power supply and the state of the energy storage device, and selecting the operating modes of the optical storage type virtual synchronous machine, the photovoltaic power supply and the energy storage device, so as to achieve power balance of the photovoltaic power supply, the energy storage and the inverter.
As a preferred scheme of the present invention, the specific steps of the selection strategy are as follows:
firstly, collecting system frequency change, and calculating the output power of the optical storage type virtual synchronous machine:
in the formula, ωgIs the angular velocity of the system, J is the virtual inertia of the rotor, D is the damping coefficient, PmFor inputting mechanical power, P is the reference value of output active power of the virtual synchronous machine, delta is the angle of output power, PrefFor input of reference power, ω0Is a reference angleSpeed, KωIs the difference coefficient of the prime mover, E is the power supply potential, UXIs the system voltage;
secondly, calculating the power difference value of the photovoltaic power supply and the light storage type virtual synchronous machine as a first index parameter theta1：
θ1＝PVSG-PPV，
In the formula, POptical storage type virtual synchronous machineFor the output power, P, of a virtual synchronous machine of the optical storage typePVThe photovoltaic output power;
thirdly, calculating the difference value between the photovoltaic real-time output power and the maximum output power as a second index theta2：
θ2＝PPV_mmp-PPV，
In the formula, PPV_mmpMaximum output power for the photovoltaic;
fourthly, according to the state of charge of the stored energy and the division of the state of charge area of the stored energy, the third index theta of the mode selection is used3：
And fifthly, selecting the working modes of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine according to the three calculated indexes and the judgment principle.
As a preferred embodiment of the present invention, the determination principle specifically includes:
when theta is1>When 0, the output power of the optical storage type virtual synchronous machine is greater than the power of the photovoltaic power supply, and the output power is equal to theta2Make a determination if theta2<0, the photovoltaic power supply has power standby, the photovoltaic power supply enters a power adjustment mode when working, and the energy storage device does not work; if theta2When the voltage of the photovoltaic power supply is equal to 0, the photovoltaic power supply is not powered for standby, the photovoltaic power supply works in a constant power mode, the energy storage device discharges electricity, and the photovoltaic power supply works in a stable direct current bus voltage mode;
when theta 1<When 0, the output power of the optical storage type virtual synchronous machine is less than the power of the photovoltaic power supply, and the output power is equal to theta3Make a determination if theta3H indicates that the energy storage nuclear power state is too high, the photovoltaic power supply works in a power adjustment mode, and the energy storage device does not work; otherwise, the photovoltaic power supply works at a constant powerIn the mode, the energy storage device is charged and works in a stable direct current bus voltage mode;
at the same time, to theta3Make a determination if theta3When the number is P, the optical storage type virtual synchronous machine enters a frequency modulation characteristic adjustment mode 1, partial frequency modulation functions are abandoned, and the nuclear power state of energy storage is maintained; if theta3And when the voltage is A, the optical storage type virtual synchronous machine enters a frequency modulation characteristic adjustment mode 2, gives up the frequency modulation function, changes the output power and charges the energy storage device.
As a preferred scheme of the present invention, the control strategy specifically includes:
when the optical storage type virtual synchronous machine receives an enabling signal 1 of an upper-layer mode selection strategy, the frequency modulation characteristic adjusting module starts to work, adjusts the output of the optical storage type virtual synchronous machine, abandons part of frequency modulation capability, enables the SOC of the energy storage device to be stable in a P area, and the control block uses the difference between (SOC _ opt + SOC _ pro)/2 and the SOC of the energy storage device as input and adds the input to Pref after passing through a PI controller;
when the optical storage type virtual synchronous machine receives the enabling signal 2 of the upper-layer mode selection strategy, the frequency modulation characteristic adjusting module starts to work, the output of the optical storage type virtual synchronous machine is adjusted, the energy storage device is charged, the SOC of the energy storage device can return to a P area, and the control block uses the difference between the SOC _ opt and the SOC of the energy storage device as input and adds the input to Pref after passing through the PI controller. That is, the control block will charge the energy storage device to a SOC greater than SOC _ opt;
when the photovoltaic receives an enabling signal of an upper-layer mode selection strategy, the photovoltaic power supply module enters a power adjustment mode to maintain the voltage of a current bus, the energy storage device does not work at the moment, the control block uses the difference between Udc _ ref and Udc as input, and the input is added to a voltage instruction value UPV _ ref of the photovoltaic power supply after passing through a PI controller, so that the photovoltaic power supply is ensured to operate on the right half side of a P-V characteristic curve, the lower limit of the PI module is 0, and the upper limit is the difference between photovoltaic open-circuit voltage Uop and Ummp;
when the energy storage device receives an enabling signal of an upper-layer mode selection strategy, the energy storage device works in a mode of maintaining a direct-current bus voltage, and the control block uses the difference between Udc _ ref and Udc as input, and adds the input to the energy storage current reference value IES _ ref after passing through the PI controller.
As a preferable aspect of the present invention, the state of the energy storage device is divided into the following five states according to the charge level of the energy storage device:
[SOC_max,1]: overcharge region, to be avoided in operation, theta3Setting to be H;
[SOC_opt,SOC_max]: optimum operating region, θ3Setting to be O;
[SOC_pro,SOC_opt]: SOC protection zone, θ3Setting as P;
[SOC_reg,SOC_pro]: SOC adjustment region, θ3Is set as R;
[SOC_far,SOC_max]: SOC buffer, θ3Setting as B;
[0,SOC_min]: over-discharge zone, to be avoided in operation, theta3Is set to L.
In addition, the invention also provides a light storage type virtual synchronous machine energy coordination management system, which comprises:
the selection strategy module is used for selecting the working modes of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine on the upper layer;
the control strategy module is used for controlling the power output of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine at the lower layer;
the photovoltaic power supply and the energy storage device are connected with an external power grid through a light storage type virtual synchronous machine, and the light storage type virtual synchronous machine coordinates the photovoltaic power supply and the energy storage device through a selection strategy module and a control strategy module.
As a preferred scheme of the present invention, the selection policy module selects the operating modes of the optical storage type virtual synchronous machine, the photovoltaic power supply and the energy storage device by analyzing the power output requirement of the optical storage type virtual synchronous machine, the photovoltaic power supply output condition and the energy storage device state, dynamically adjusts the virtual characteristics of the photovoltaic power supply output and the optical storage type virtual synchronous machine, and realizes the power balance of the photovoltaic power supply, the energy storage and the inverter.
The embodiment of the invention has the following advantages:
according to the invention, the output characteristics of photovoltaic, energy storage and VSG are dynamically adjusted by analyzing the power output requirement of VSG, the output condition of the photovoltaic power supply and the SOC state of the energy storage device, so that the photovoltaic, the energy storage and the virtual synchronous machine all participate in the power balance process, and the dependence of VSG on the energy storage capacity is effectively improved;
the invention adopts asymmetric control on the SOC of the energy storage device, so that the SOC of the energy storage can be maintained at a higher level, and the VSG always has enough spare capacity to ensure the characteristic of the virtual synchronous machine;
the invention preferentially ensures the inertia of the virtual synchronous machine, so that the optical storage type synchronous generator can not lose the function completely due to insufficient energy storage capacity.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.
FIG. 1 is a block diagram of a light storage type virtual synchronous machine according to the present invention;
FIG. 2 is a block diagram of the upper level strategy of the present invention;
FIG. 3 is a SOC partition diagram of the energy storage device of the present invention;
FIG. 4 is a control frame diagram of the inverter of the present invention;
FIG. 5 is a control frame diagram of a photovoltaic module of the present invention;
FIG. 6 is a control frame diagram of the energy storage device of the present invention;
FIG. 7 is a graph of the output power of the virtual synchronous machine of the present invention;
FIG. 8 is the output power of a photovoltaic module of the present invention;
FIG. 9 is a SOC of the energy storage device of the present invention;
FIG. 10 is a flow chart of the management method of the present invention.
Detailed Description
The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 10, the present invention provides a method for energy coordination management of an optical storage type virtual synchronous machine, including:
the photovoltaic power supply, the energy storage device and the light storage type virtual synchronous machine on the upper layer are subjected to a working mode selection strategy;
and the power output control strategy of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine on the lower layer.
Also provided is a light storage type virtual synchronous machine energy coordination management system, including:
the selection strategy module is used for selecting the working modes of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine on the upper layer;
the control strategy module is used for controlling the power output of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine at the lower layer;
the photovoltaic power supply and the energy storage device are connected with an external power grid through a light storage type virtual synchronous machine, and the light storage type virtual synchronous machine coordinates the photovoltaic power supply and the energy storage device through a selection strategy module and a control strategy module.
An embodiment of the present invention is shown in fig. 1 to 9. On the direct current side of the light storage distributed power generation system, a photovoltaic array and an energy storage device are respectively connected in parallel on a direct current bus through a DC/DC converter; the direct current is converted into alternating current through an inverter controlled by a virtual synchronous strategy and then is output to a local load and a power grid through a filter circuit; the output side of the inverter is connected with the power grid through a grid-connected switch.
The DC/DC converter connected with the photovoltaic module adopts a Boost circuit and is used for realizing maximum power tracking control or constant power control; and the bidirectional DC/DC circuit is connected with the energy storage and used for realizing constant voltage control and maintaining the voltage of the direct current bus by balancing the difference between the photovoltaic power generation and the output power of the inverter through charging and discharging.
The VSG is adopted by the inverter to control the mechanical property and the electromagnetic property of the analog synchronous generator, so that the inverter has the frequency modulation capability and inertia of the synchronous generator. The invention mainly considers the active power control of the virtual synchronous machine, so the excitation characteristic simulation of the synchronous machine is omitted.
The inertia of a synchronous generator is determined by its mechanical characteristics, represented by its rotor equation of motion. The present embodiment employs a classical second-order model, as shown in the following equation.
In the formula: omegagIs the angular velocity of the system; j is the virtual inertia of the rotor; d is a damping coefficient; p is the output active power of VSG; pmIs mechanical power; delta is the output power angle.
The virtual synchronous machine also needs to simulate the frequency modulation process of the synchronous machine. The speed regulation process of the synchronous generator is simplified, and only the static characteristic of the speed regulator is introduced, namely:
Pref-P＝Kω(ω-ω0)
in the formula: prefIs a reference power; omega0Is a reference angular velocity; kωIs the adjustment coefficient of the prime motor.
Let the synchronous resistance of VSG be RsSynchronous reactance of LsThen, the electromagnetic characteristic equation of the synchronous generator can be obtained as follows:
in the formula idAnd iqAre the dq-axis components of the current, u, respectivelydAnd uqRespectively, the dq-axis components of the voltage.
The energy coordination management method of the light storage type virtual synchronous power generation system is divided into an upper layer and a lower layer.
The upper-layer power distribution working mode selection strategy selects the working modes of the virtual synchronous machine, the photovoltaic and the energy storage by analyzing the power output requirement of the VSG, the output condition of the photovoltaic power supply and the SOC state of the energy storage device, and a control block diagram of the strategy is shown in FIG. 2 and comprises the following five steps:
firstly, collecting system frequency change, and calculating an output power photovoltaic module of the virtual synchronous machine according to a characteristic equation of the virtual synchronous machineSG；
Secondly, calculating the power difference value of the photovoltaic and the virtual synchronous machine as a first index parameter theta1：θ1＝PVSG-PPVIn the formula, PVSGFor virtual synchronous machine output power, PPVThe photovoltaic output power;
thirdly, calculating the difference value between the photovoltaic real-time output power and the maximum output power as a second index theta2：θ2＝PPV_mmp-PPV，[068]In the formula, PPV_mmpMaximum output power for the photovoltaic;
fourthly, according to the invention, the state of charge of the stored energy is divided (as shown in fig. 3), and a third index theta is obtained3；
And fifthly, selecting the working modes of the photovoltaic, energy storage and virtual synchronous machine according to the three calculated index parameters and the following principles:
when theta is1>At 0, it indicates that the VSG output power is greater than the photovoltaic module power. To theta2Make a determination if theta2<0, the photovoltaic module is in power standby, the photovoltaic module works to enter a power adjustment mode, and the energy storage device does not work; if theta2With 0, the photovoltaic module is shown without power backup. The photovoltaic module works in a constant power mode, the energy storage device discharges electricity, and the photovoltaic module works in a stable direct current bus voltage mode;
when theta is1<At 0, it indicates that the VSG output power is less than the photovoltaic module power. To theta3Make a determination if theta3If the voltage is H, the energy storage nuclear power state is too high, the photovoltaic module works in a power adjustment mode, and the energy storage device does not work; whether or notThen, the photovoltaic module works in a constant power mode, the energy storage device is charged, and the photovoltaic module works in a stable direct current bus voltage mode;
at the same time, to theta3Make a determination if theta3When the number is P, the virtual synchronous machine enters a frequency modulation characteristic adjustment mode 1, partial frequency modulation functions are abandoned, and the nuclear power state of energy storage is maintained; if theta3When the frequency modulation characteristic is A, the virtual synchronous machine enters a frequency modulation characteristic adjustment mode 2, the frequency modulation function is abandoned, the output power is changed, and the energy storage device is charged;
and the power output control strategy of the lower layer controls the power output of the virtual synchronous machine, the photovoltaic and the energy storage device according to the working mode of each module selected by the upper layer strategy.
The complete control strategy block diagram of the inverter is shown in fig. 4. And when the system runs stably, the frequency modulation capability adjusting module in the control block diagram does not work. When the enable signal is received, the frequency modulation capability adjusting module reduces the reference power value PrefThe frequency modulation characteristic of the system is shifted to the left, the output power of the VSG is reduced at the moment, and part of the load is transferred to other power supplies in the system. The specific implementation method comprises the following steps: when the inverter receives an enabling signal 1 of an upper-layer mode selection strategy, the frequency modulation characteristic adjusting module adjusts the output of the VSG, abandons part of frequency modulation capacity, enables the SOC of the energy storage device to be stable in a P area, uses the difference between (SOC _ opt + SOC _ pro)/2 and the SOC of the energy storage device as input, and adds the input to P after passing through a PI controllerrefThe above step (1); when the virtual synchronous machine receives an enabling signal 2 of an upper-layer mode selection strategy, the frequency modulation characteristic adjusting module starts to work, the output of the VSG is adjusted, the energy storage device is charged, the SOC of the energy storage device can return to a P area, the difference between the SOC _ opt and the SOC of the energy storage device is used as input, and the input is added to the P area after passing through the PI controllerrefThe above. I.e. the control block will charge the energy storage device to a SOC greater than SOC _ opt.
The control block diagram of the photovoltaic module is shown in fig. 5. When the photovoltaic power supply operates stably, the photovoltaic module works in a maximum power mode, when the photovoltaic module receives an enabling signal of an upper mode selection strategy, the photovoltaic module enters a power adjustment mode to change the direct-current voltage of the photovoltaic module, and the output power of the photovoltaic module is output according to the power-voltage characteristic of the photovoltaic power supplyIt will adjust accordingly. The specific implementation method comprises the following steps: using UdcR < f > and UdcIs added to the voltage command value U of the photovoltaic module after passing through the PI controller as an inputPV_ref. In order to ensure that the photovoltaic module operates on the right half side of the P-V characteristic curve, the lower limit of the PI module is 0, and the upper limit is the photovoltaic open-circuit voltage UopAnd UmmpThe difference of (a).
A control block diagram of the energy storage device is shown in fig. 6. When the energy storage device receives an enabling signal of the upper-layer mode selection strategy, the energy storage device works in a mode of maintaining the direct-current bus voltage. The control block uses the difference between Udc _ ref and Udc as input, and adds to the stored current reference value IES _ ref after passing through the PI controller.
The light storage type virtual synchronous power generation system was simulated for 10 seconds. In the simulation, 0-1s, the system is in a balanced state; 1-4s, increasing the load level so that the system frequency is reduced to 48.7 Hz; 4-10S, the load level continues to increase, causing the system frequency to drop to 49.6 hHz.
VSG output power P is obtained through simulationVSGPhotovoltaic output power PPVThe energy storage device SOC is shown in fig. 7 to 9.
As can be seen from fig. 7 to 9, at 1 to 4s, the load level increases, the system frequency decreases, and the photovoltaic module has spare capacity, and the photovoltaic module is controlled to increase the output power.
And at 4-7.1s, the load level continues to increase, the power output by the VSG according to the frequency modulation characteristic is already greater than the output power of the photovoltaic module, the energy storage device makes up the power difference, and the SOC of the energy storage device is rapidly reduced at the moment.
And at 7.1s-10s, the SOC level of the energy storage device is reduced to be below 0.5, and the SOC protection state of the energy storage device is reached, and the frequency modulation characteristic of the VSG is adjusted, so that the output power of the VSG is reduced. So that the SOC of the energy storage device can not be further reduced, and the inertia of the VSG is ensured.
Although the invention has been described in detail above with reference to a general description and specific examples, it will be apparent to one skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (8)
1. A method for energy coordination management of a light storage type virtual synchronous machine is characterized by comprising the following steps:
selecting a working mode according to a working mode selection strategy of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine on the upper layer;
and carrying out power output control according to power output control strategies of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine at the lower layer.
2. The method according to claim 1, wherein the selection strategy is used for dynamically adjusting the virtual characteristics of the photovoltaic power output and the optical storage type virtual synchronous machine to achieve power balance of the photovoltaic power supply, the energy storage and the inverter by analyzing the power output requirement of the optical storage type virtual synchronous machine, the photovoltaic power output condition and the energy storage device state, selecting the operating modes of the optical storage type virtual synchronous machine, the photovoltaic power supply and the energy storage device.
3. The method for energy coordination management of the light storage type virtual synchronous machine according to claim 2, wherein the specific steps of selecting the policy are as follows:
firstly, collecting system frequency change, and calculating the output power of the optical storage type virtual synchronous machine:
in the formula, ωgIs the angular velocity of the system, J is the virtual inertia of the rotor, D is the damping coefficient, PmFor inputting mechanical power, P is the reference value of output active power of the virtual synchronous machine, delta is the angle of output power, PrefFor input of reference power, ω0For reference angular velocity, KωIs the difference coefficient of the prime mover, E is the power supply potential, UXIs the system voltage;
secondly, calculating the power difference value of the photovoltaic power supply and the light storage type virtual synchronous machine as a first index parameter theta1：
θ1＝PVSG-PPV，
In the formula, POptical storage type virtual synchronous machineFor the output power, P, of a virtual synchronous machine of the optical storage typePVThe photovoltaic output power;
thirdly, calculating the difference value between the photovoltaic real-time output power and the maximum output power as a second index theta2：
θ2＝PPV_mmp-PPV，
In the formula, PPV_mmpMaximum output power for the photovoltaic;
fourthly, according to the state of charge of the stored energy and the division of the state of charge area of the stored energy, the third index theta of the mode selection is used3：
And fifthly, selecting the working modes of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine according to the three calculated indexes and the judgment principle.
4. The method according to claim 3, wherein the determination principle specifically includes:
when theta is1>When 0, the output power of the optical storage type virtual synchronous machine is greater than the power of the photovoltaic power supply, and the output power is equal to theta2Make a determination if theta2<0, the photovoltaic power supply has power standby, the photovoltaic power supply enters a power adjustment mode when working, and the energy storage device does not work; if theta2When the voltage of the photovoltaic power supply is equal to 0, the photovoltaic power supply is not powered for standby, the photovoltaic power supply works in a constant power mode, the energy storage device discharges electricity, and the photovoltaic power supply works in a stable direct current bus voltage mode;
when theta 1<When 0, the output power of the optical storage type virtual synchronous machine is less than the power of the photovoltaic power supply, and the output power is equal to theta3Make a determination if theta3H indicates that the energy storage nuclear power state is too high, the photovoltaic power supply works in a power adjustment mode, and the energy storage device does not work; otherwise, photovoltaic electricityThe source works in a constant power mode, the energy storage device is charged, and the source works in a stable direct current bus voltage mode;
at the same time, to theta3Make a determination if theta3When the number is P, the optical storage type virtual synchronous machine enters a frequency modulation characteristic adjustment mode 1, partial frequency modulation functions are abandoned, and the nuclear power state of energy storage is maintained; if theta3And when the voltage is A, the optical storage type virtual synchronous machine enters a frequency modulation characteristic adjustment mode 2, gives up the frequency modulation function, changes the output power and charges the energy storage device.
5. The method for energy coordination management of a light storage type virtual synchronous machine according to claim 4, wherein the control policy specifically includes:
when the optical storage type virtual synchronous machine receives an enabling signal 1 of an upper-layer mode selection strategy, the frequency modulation characteristic adjusting module starts to work, adjusts the output of the optical storage type virtual synchronous machine, abandons part of frequency modulation capability, enables the SOC of the energy storage device to be stable in a P area, and the control block uses the difference between (SOC _ opt + SOC _ pro)/2 and the SOC of the energy storage device as input and adds the input to Pref after passing through a PI controller;
when the optical storage type virtual synchronous machine receives the enabling signal 2 of the upper-layer mode selection strategy, the frequency modulation characteristic adjusting module starts to work, the output of the optical storage type virtual synchronous machine is adjusted, the energy storage device is charged, the SOC of the energy storage device can return to a P area, and the control block uses the difference between the SOC _ opt and the SOC of the energy storage device as input and adds the input to Pref after passing through the PI controller. That is, the control block will charge the energy storage device to a SOC greater than SOC _ opt;
when the photovoltaic receives an enabling signal of an upper-layer mode selection strategy, the photovoltaic power supply module enters a power adjustment mode to maintain the voltage of a current bus, the energy storage device does not work at the moment, the control block uses the difference between Udc _ ref and Udc as input, and the input is added to a voltage instruction value UPV _ ref of the photovoltaic power supply after passing through a PI controller, so that the photovoltaic power supply is ensured to operate on the right half side of a P-V characteristic curve, the lower limit of the PI module is 0, and the upper limit is the difference between photovoltaic open-circuit voltage Uop and Ummp;
when the energy storage device receives an enabling signal of an upper-layer mode selection strategy, the energy storage device works in a mode of maintaining a direct-current bus voltage, and the control block uses the difference between Udc _ ref and Udc as input, and adds the input to the energy storage current reference value IES _ ref after passing through the PI controller.
6. The energy coordination management method for the optical storage type virtual synchronous machine according to claim 1, wherein the state of the energy storage device is divided into the following five states according to the charge level of the energy storage device:
[SOC_max,1]: overcharge region, to be avoided in operation, theta3Setting to be H;
[SOC_opt,SOC_max]: optimum operating region, θ3Setting to be O;
[SOC_pro,SOC_opt]: SOC protection zone, θ3Setting as P;
[SOC_reg,SOC_pro]: SOC adjustment region, θ3Is set as R;
[SOC_far,SOC_max]: SOC buffer, θ3Setting as B;
[0,SOC_min]: over-discharge zone, to be avoided in operation, theta3Is set to L.
7. An optical storage type virtual synchronous machine energy coordination management system applied to the method of claim 1, characterized by comprising:
the selection strategy module is used for selecting the working modes of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine on the upper layer;
the control strategy module is used for controlling the power output of the photovoltaic power supply, the energy storage device and the optical storage type virtual synchronous machine at the lower layer;
the photovoltaic power supply and the energy storage device are connected with an external power grid through a light storage type virtual synchronous machine, and the light storage type virtual synchronous machine coordinates the photovoltaic power supply and the energy storage device through a selection strategy module and a control strategy module.
8. The system according to claim 7, wherein the selection policy module dynamically adjusts the virtual characteristics of the photovoltaic power output and the optical storage type virtual synchronous machine to achieve power balance among the photovoltaic power, the energy storage and the inverter by analyzing the power output requirement, the photovoltaic power output condition and the energy storage device state of the optical storage type virtual synchronous machine, selecting the operating modes of the optical storage type virtual synchronous machine, the photovoltaic power and the energy storage device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911261554.6A CN111030170B (en) | 2019-12-10 | 2019-12-10 | Energy coordination management method and system for optical storage type virtual synchronous machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911261554.6A CN111030170B (en) | 2019-12-10 | 2019-12-10 | Energy coordination management method and system for optical storage type virtual synchronous machine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111030170A true CN111030170A (en) | 2020-04-17 |
| CN111030170B CN111030170B (en) | 2023-01-20 |
Family
ID=70208647
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911261554.6A Active CN111030170B (en) | 2019-12-10 | 2019-12-10 | Energy coordination management method and system for optical storage type virtual synchronous machine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111030170B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114498763A (en) * | 2022-01-10 | 2022-05-13 | 新源智储能源发展(北京)有限公司 | Control method of optical storage virtual synchronous generator for limiting energy storage charging and discharging power |
| CN114552661A (en) * | 2022-04-22 | 2022-05-27 | 深圳市德兰明海科技有限公司 | Light storage power generation system control method and storage medium |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108418257A (en) * | 2018-04-23 | 2018-08-17 | 华北电力科学研究院有限责任公司 | Photovoltaic virtual synchronous machine light stores up control method for coordinating and device |
| CN108565885A (en) * | 2018-01-16 | 2018-09-21 | 浙江大学 | A kind of mesohigh large capacity cascade type energy storage system control method based on VSG |
| CN109861258A (en) * | 2019-03-06 | 2019-06-07 | 华北电力大学（保定） | A kind of virtual synchronous machine primary frequency modulation performance on-line evaluation method |
| CN109921461A (en) * | 2019-03-06 | 2019-06-21 | 华北电力大学（保定） | The evaluation of virtual synchronous generator primary frequency modulation performance and Parameter Optimization System |
| CN110277803A (en) * | 2019-07-30 | 2019-09-24 | 西安西电电气研究院有限责任公司 | A kind of the virtual synchronous generator control method and control device of energy accumulation current converter |
-
2019
- 2019-12-10 CN CN201911261554.6A patent/CN111030170B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108565885A (en) * | 2018-01-16 | 2018-09-21 | 浙江大学 | A kind of mesohigh large capacity cascade type energy storage system control method based on VSG |
| CN108418257A (en) * | 2018-04-23 | 2018-08-17 | 华北电力科学研究院有限责任公司 | Photovoltaic virtual synchronous machine light stores up control method for coordinating and device |
| CN109861258A (en) * | 2019-03-06 | 2019-06-07 | 华北电力大学（保定） | A kind of virtual synchronous machine primary frequency modulation performance on-line evaluation method |
| CN109921461A (en) * | 2019-03-06 | 2019-06-21 | 华北电力大学（保定） | The evaluation of virtual synchronous generator primary frequency modulation performance and Parameter Optimization System |
| CN110277803A (en) * | 2019-07-30 | 2019-09-24 | 西安西电电气研究院有限责任公司 | A kind of the virtual synchronous generator control method and control device of energy accumulation current converter |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114498763A (en) * | 2022-01-10 | 2022-05-13 | 新源智储能源发展(北京)有限公司 | Control method of optical storage virtual synchronous generator for limiting energy storage charging and discharging power |
| CN114552661A (en) * | 2022-04-22 | 2022-05-27 | 深圳市德兰明海科技有限公司 | Light storage power generation system control method and storage medium |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111030170B (en) | 2023-01-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Mao et al. | Decentralized coordination power control for islanding microgrid based on PV/BES-VSG | |
| CN107196341A (en) | The two-stage type of Variable power point tracking is without energy storage photovoltaic virtual synchronous machine control method | |
| Kotra et al. | Energy management of hybrid microgrid with hybrid energy storage system | |
| CN112398166A (en) | Parameter analysis method for energy storage primary frequency modulation virtual synchronous machine | |
| US9964978B2 (en) | Control systems for microgrid power inverter and methods thereof | |
| CN104578857A (en) | Control method and device of photovoltaic power generation system and photovoltaic power generation system | |
| Virulkar et al. | Integrated battery controller for distributed energy system | |
| CN107482659B (en) | Exchange mixed energy storage system control method for coordinating under micro-capacitance sensor off-network state | |
| CN111030170B (en) | Energy coordination management method and system for optical storage type virtual synchronous machine | |
| CN113472016B (en) | Control method of household energy router | |
| WO2021173136A1 (en) | System and method for control of hybrid renewable energy storage system | |
| CN115864520A (en) | Control method and system for accessing hybrid power grid based on high-proportion photovoltaic energy | |
| Rabhi et al. | Energy management for an autonomous renewable energy system | |
| Wang et al. | SOC balancing method for hybrid energy storage system in microgrid | |
| Akbari et al. | A PSO solution for improved voltage stability of a hybrid ac-dc microgrid | |
| Idan et al. | Optimized proportional-integral controller for a photovoltaic-virtual synchronous generator system | |
| CN210927122U (en) | Optical storage type virtual synchronous machine | |
| Shi et al. | A virtual synchronous generator system control method with battery SOC feedback | |
| CN114552662B (en) | Light storage power generation system control method and storage medium | |
| Eid | Control of hybrid energy systems micro-grid | |
| CN112510751B (en) | Multi-microgrid balance unit system architecture and control coordination method | |
| CN111900749B (en) | Network source coordination virtual synchronous machine control method of optical storage integrated system | |
| Guo et al. | Control strategies for a hybrid PV/battery system with grid-connected and island mode | |
| CN112688356A (en) | Method and system for controlling operation of multi-energy direct-current micro-grid | |
| Saha et al. | Power quality improvement of a self-excited induction generator using nfpi controller based hybrid statcom system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |