CN208386163U - Photovoltaic power station user side three-phase imbalance counter-flow-preventing device - Google Patents
Photovoltaic power station user side three-phase imbalance counter-flow-preventing device Download PDFInfo
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- CN208386163U CN208386163U CN201821106707.0U CN201821106707U CN208386163U CN 208386163 U CN208386163 U CN 208386163U CN 201821106707 U CN201821106707 U CN 201821106707U CN 208386163 U CN208386163 U CN 208386163U
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Abstract
The utility model discloses a kind of photovoltaic power station user side three-phase imbalance counter-flow-preventing device, anti-backflow device is made of rectified three-phase circuit, bidirectional DC-DC converter circuit, energy-storage battery and the microprocessor for being connected in parallel on load-side；The end of incoming cables of rectified three-phase circuit is connect with photovoltaic DC-to-AC converter leading-out terminal, and leading-out terminal successively connects and composes the charging major loop of out-of-balance current with bi-directional DC-DC circuit, energy-storage battery；The leading-out terminal of rectified three-phase circuit is connect with the end of incoming cables of inverter by contactless contactor simultaneously, forms battery discharge circuit.Microprocessor realizes the charge and discharge control to battery by driving rectified three-phase circuit, contactless contactor and DC-DC circuit switching tube.The system combines distributed photovoltaic power generation with battery energy storage system, while by load-side parallel connection energy-storage system, solving the problems, such as electric current adverse current power grid caused by user side threephase load is uneven, safe and stable, the economical operation of effective safeguards system.
Description
Technical field
The utility model belongs to photovoltaic power station technical field, and in particular to one kind is suitable for photovoltaic power station
The counter-flow-preventing device based on battery energy storage under the conditions of user side threephase load is uneven.
Background technique
Photovoltaic array, the header box that distributed photovoltaic power generation is made of multiple photovoltaic modulies through series-parallel connection appropriate
And inverter is constituted, it is a kind of new energy power generation technology with broad development space, can convert the solar into electricity
It can be used for load.Distributed photovoltaic power generation is generated power for their own use by user side, is run in a manner of the online of extra electricity, it advocates nearest
Power generation, nearby grid-connected, nearest conversion, the principle used nearby.Due to the unpredictable and fluctuation of photovoltaic power generation output power,
Make it generate maximum photovoltaic output power frequently with maximum power point tracking technology to be connected to the grid, photovoltaic power generation makes for low-voltage customer
Used time, there is no the actual consumption situations in view of load, when bearing power is less than photovoltaic generation power or three-phase when grid-connected
When the bearing power of certain phase is less than photovoltaic generation power in load, it will lead to photovoltaic generating system to power grid loopback energy, occur
Backflow phenomena.
Low-voltage customer supply network is usually three-phase productive power and single-phase load mixing electricity consumption, in actual moving process
Uncontrollable increase-volume, the asynchronism of single-phase load electricity consumption and the access of great power single phase load of single-phase user will lead to three
The imbalance of phase load.For threephase load imbalance problem, most of research is all by installing compensation device additional to it not
Balance component compensates, since load is determined by the electricity consumption actual conditions of user, unbalanced load be always existing for,
Compensation device can only guarantee that grid-connected grid side voltage and current is in equilibrium state to a certain extent.Since distributed photovoltaic is sent out
The inverter of electricity forces the three-phase electricity of balance to will lead to load when laod unbalance occurs in user side with maximum power output
The a certain phase in side or biphase current reversely flow back towards power grid and generate energy loss, while impacting to the safe and stable operation of system.
Based on the above thinking, by backflow phenomena caused by uneven to threephase load in load-side parallel connection energy storage device into
Row is effective to be inhibited, in general, energy storage device includes battery pack, DC-DC converter, charge-discharge control circuit etc..Make in load-side
It is realized with SCR rectification circuit connection energy storage device and the dynamic memory of out-of-balance current is controlled, increase the spirit of system control
Activity；Cache station of the energy storage device as energy, realizes the flow of power of each phase, thus achieve the purpose that each phase current of balance,
While improving system performance, system entirety utilizability is improved.For laod unbalance problem, how to prevent
While adverse current adversely affects system, photovoltaic energy is utilized to greatest extent, ensures the safe, steady of photovoltaic generating system
Fixed, economical operation, is present urgent problem.
Utility model content
In order to solve adverse effect caused by electric current adverse current power grid caused by user side threephase load imbalance, this is practical new
Type proposes a kind of photovoltaic power station user side three-phase imbalance counter-flow-preventing device based on battery energy storage, utilizes controllable device
The mode that part is combined with energy storage device is connected in parallel on load-side, is realized to the electricity of imbalance caused by three-phase imbalance load
The dynamic regulation of stream effectively avoids a certain phase of load-side caused by three characteristics of the middle term laod unbalance or biphase current adverse current power grid
Caused by the adverse effect such as energy loss.
It is as follows that the utility model solves technical solution used by its technical problem:
A kind of photovoltaic power station user side three-phase imbalance counter-flow-preventing device, including it is negative with photovoltaic power station
Carry rectified three-phase circuit, bidirectional DC-DC converter circuit, energy-storage battery and the microprocessor of side parallel connection；The distributed photovoltaic electricity
It stands and keeps maximum power output, force output three-phase equilibrium alternating current to load for low-voltage customer through inverter and use；The three-phase
The leading-out terminal of rectification circuit successively connects and composes the charging major loop of out-of-balance current with bi-directional DC-DC circuit, energy-storage battery；Three
The leading-out terminal of commutating phase circuit is connect with the end of incoming cables of inverter by contactless contactor simultaneously, forms battery discharge circuit；Institute
The microprocessor stated is connect with detection module, for detecting the three-phase current of inverter outlet side current value and load-side respectively
The relevant informations such as value drive the switching tube of rectification circuit thyristor, contactless contactor and DC-DC circuit by calculation process
Realize control function.
The rectified three-phase circuit is made of six thyristors, wherein thyristor VT1 and thyristor VT4, thyristor VT3 with
Thyristor VT6 and thyristor VT5 and thyristor VT2 respectively constitutes three groups of upper and lower bridge arms, two arm alternatings up and down of same half-bridge
It is conductive.
The bi-directional DC-DC circuit is formed by BUCK circuit and BOOST circuit inverse parallel.
The battery energy storage unit is nickel hydrogen storage battery, lithium-ions battery or fuel cell.
The output end of the detection circuit connection inverter is used to detect the three-phase equilibrium electric current of inverter output, detection electricity
The input terminal of road connection load is used to detect the three phase unbalance current of load-side, and detection circuit connection energy-storage battery is for detecting
Its end voltage.
The microprocessor is connect with man-machine interface, or is connect by telecommunication circuit with remote monitoring system.
By above technical scheme, the utility model has the following beneficial effects:
The photovoltaic power station user side three-phase imbalance counter-flow-preventing device of the utility model, using controllable devices with
The mode that energy storage device combines is connected in parallel on load-side, is realized to out-of-balance current caused by three-phase imbalance load
Dynamic regulation efficiently solves energy caused by a certain phase of load-side caused by threephase load imbalance or biphase current adverse current power grid
The adverse effects such as amount loss；It, will by being detected to inverter output current, load-side three-phase current and battery terminal voltage
Detection signal is transmitted to microprocessor, and corresponding trigger pulse is exported by the control algolithm of microprocessor and realizes imbalance
The storage of phase current, under the conditions of solving laod unbalance, a certain phase of load-side or biphase current reversely flow back towards power grid and pacify to system
Adverse effect caused by full stable operation, while avoiding the loss of uneven phase energy.The system is cleverly by distributed light
Overhead utility is combined with battery energy storage system, by control rectified three-phase circuit respective thyristor conducting, contactless contactor and
The on-off of switching tube realizes the charge and discharge control of energy storage device.It simultaneously also can be effectively by light under threephase load equilibrium condition
It lies prostrate extra generated energy to store in time, at night or cloudy photovoltaic power generation deficiency, release is used for load, to alleviate power grid confession
Voltage force.Solve user side threephase load imbalance cause reflux problem while, effective safeguards system it is safe, steady
Fixed, economical operation.
Further, balancing transformer is integrated in inverter, and output three-phase equilibrium electricity can be forced to make for low-voltage customer load
With.
Further, microprocessor is connected by controlling respective thyristor and DC-DC circuit respective switch pipe is cooperated to make its work
Make to realize the charge control to load three phase unbalance current in decompression state；It is switched by control contactor and cooperates DC-DC
Circuit respective switch pipe makes its work in pressure-increasning state, realizes the control of discharge of energy storage device.
Detailed description of the invention
Fig. 1 is the overall system architecture figure using the utility model method；
Fig. 2 is the energy-storage battery charge-discharge control circuit figure using the counter-flow-preventing device of the utility model method；
Fig. 3 is the microprocessor control system schematic diagram using the utility model method；
Fig. 4 is the energy-storage battery charge and discharge control process signal using the utility model method under the conditions of unbalanced load
Figure.
Specific embodiment
It is practical to this with reference to the accompanying drawing in order to keep the working principle, technical solution of the utility model more clear intuitive
Novel preferred embodiment elaborates.Obvious, described specific example only to explain the utility model, does not limit
The utility model.
The example of the utility model provides a kind of photovoltaic power station user side three-phase imbalance counter-flow-preventing device, system
Overall structure block diagram as shown in Figure 1, since laod unbalance exists always, load-side by controllable devices in conjunction with energy-storage system
Form anti-backflow device.The device includes the rectified three-phase circuit in parallel with photovoltaic power station user load side, two-way DC-
DC translation circuit, energy-storage battery and microprocessor；The direct current that the photovoltaic power station issues is kept by booster converter
Enter DC power distribution cabinet after maximum power output after header box summarizes, DC power distribution cabinet obtains three-phase equilibrium through inverter and exchanges
Electricity is used for load；Inverter is connect with three-phase controllable silicon rectification circuit simultaneously, and the leading-out terminal of the rectified three-phase circuit is successively
The charging major loop of out-of-balance current is connected and composed with bi-directional DC-DC circuit, energy-storage battery；The leading-out terminal of rectified three-phase circuit is same
When and inverter end of incoming cables pass through contactless contactor connect, formed battery discharge circuit；The bi-directional DC-DC circuit is by BUCK
Circuit and BOOST circuit inverse parallel form, and are realized by the on-off and combination rectification circuit of control switch pipe to energy-storage battery
Charge and discharge mode control；The microprocessor connect driving rectified three-phase circuit, contactless contactor and DC- with detection module
The switching tube of DC circuit realizes the charge and discharge control to energy storage device.
Balancing transformer is integrated in the inverter, and output three-phase equilibrium electricity can be forced to load for low-voltage customer and used.
It is connect by bi-directional DC-DC circuit with energy-storage battery after the output end of inverter is connect with rectified three-phase circuit simultaneously, constitutes storage
The charging major loop of energy battery；The input terminal of inverter is connect by contactless contactor with energy storage device, and energy-storage battery is constituted
Discharge loop.
The energy storage device includes bidirectional DC-DC converter circuit and energy-storage battery unit, and the energy-storage battery unit can
To be the energy-storage systems such as nickel hydrogen storage battery, lithium-ions battery, fuel cell.
For the anti-backflow device based on battery energy storage of three-phase imbalance load design, charge-discharge control circuit figure is such as
Shown in Fig. 2, inverter output end is connect with rectified three-phase circuit, the leading-out terminal of the rectified three-phase circuit successively with two-way DC-
DC circuit, energy-storage battery unit connect the charging major loop to form out-of-balance current；The leading-out terminal of rectified three-phase circuit simultaneously with
The end of incoming cables of inverter is connected by contactless contactor, forms the discharge loop of energy-storage battery unit.
The rectified three-phase circuit is using thyristor device and cooperates the switching tube of DC-DC conversion circuit that load can be realized
The energy storage of the corresponding phase in side controls.Rectified three-phase circuit uses thyristor, constitutes six bridge arms altogether, wherein thyristor VT1 and VT4,
Thyristor VT3 and VT6 and thyristor VT5 and VT2 respectively constitutes three groups of upper and lower bridge arms, and two arms up and down of same half-bridge are alternately led
Electricity.The rectified three-phase circuit uses thyristor device, and it is more to loading to control respective thyristor conducting realization by microprocessor
The energy storage of remaining phase controls.
The bi-directional DC-DC circuit is formed by BUCK circuit and BOOST circuit inverse parallel, passes through the on-off of control switch pipe
And it combines rectification circuit to realize and the charge and discharge mode of energy-storage battery is controlled.
The three-phase equilibrium electric current of the output end detection inverter output of the detection circuit connection inverter, connects load
Input terminal detects the three phase unbalance current of load-side respectively, and connection energy-storage battery detects its end voltage etc.；The detection module
It relies primarily on microprocessor and corresponding detection circuit is designed to realize coherent detection function by voltage-current sensor.
The three phase unbalance current of three-phase equilibrium electric current i, load-side that the microprocessor real-time detection inverter exports
ij' (j=a, b, c) and energy-storage battery end voltage Uc, made the difference by the output electric current to inverter with load-side three-phase current
It calculates, and by difference result and zero comparative analysis, according to comparison result and the battery terminal voltage size detected is combined to control
The conducting of respective thyristor and switching tube realizes that the energy storage charge control of the extra phase electric energy of load-side or control contactor are closed
Close the control of discharge for realizing energy storage device supplement photovoltaic generation deficiency.The working principle of specific control system is as shown in Figure 3.
The photovoltaic power station user side three-phase imbalance counter-flow-preventing device, by load-side controllable device in parallel
Part and energy storage device are to solve laod unbalance current problems, for the energy storage device charge and discharge control implementation process of the system
As shown in figure 4, the parameter information arrived according to real-time detection, such as inverter output current value, threephase load current value, by micro-
Processor internal analysis comparison, obtains the charge and discharge control state of energy storage device under the conditions of different parameters.
The microprocessor passes through the parameter information detected, realizes charging control of the energy storage device to laod unbalance electric current
System, specifically: microprocessor real-time detection relevant parameter, when detecting inverter outlet side current value and load-side three-phase current
Difference in there is the case where being greater than zero, illustrate to exist in load-side three-phase and need the extra electric energy that stores.When detecting inversion
The case where being all larger than zero there are three-phase in the difference of device outlet side current value and load-side three-phase current, illustrates load-side three-phase electricity
There is residue, scr rectification circuit needs to complete the rectification of extra three-phase electricity at this time, and microprocessor is with inverter outlet side electricity
Stream completes each mutually extra electricity with opening for corresponding thyristor is controlled subject to the maximum phase of load-side three-phase current difference
Rectification and storage；It is greater than zero when only existing two-phase in the difference for detecting inverter outlet side current value and load-side three-phase current
The case where, illustrate that load-side has two-phase electric energy to have residue, microprocessor is with inverter outlet side electric current and load-side three-phase current
Another extra corresponding thyristor is controlled subject to the maximum phase of difference opens the rectification and storage for completing extra phase electricity；
When only exist a phase in the difference for detecting inverter outlet side current value and load-side three-phase current greater than zero the case where, explanation
Load-side only has a phase electric energy to have residue, and microprocessor is by controlling the extra corresponding turn on thyristors of phase current, remaining phase
Corresponding thyristor cooperates the thyristor of the extra phase to complete the rectification and storage of extra phase electric energy.Microprocessor is examined in real time simultaneously
The end voltage for surveying energy-storage battery, when detecting the end voltage of battery in the chargeable range of permission, microprocessor control is accordingly
Switching tube makes DC-DC circuit work be depressured charged state in BUCK；When microprocessor detects that the end voltage of battery is permitted beyond it
Perhaps maximum charging voltage then stops charging.
The microprocessor passes through the parameter information detected, realizes the electric discharge control of the energy storage device in photovoltaic power generation deficiency
System, specifically: microprocessor real-time detection relevant parameter, when detecting inverter outlet side current value and load-side three-phase current
Difference there is no any phase be greater than zero the case where, illustrate photovoltaic power generation be not enough to for load use, microprocessor control at this time
The control of discharge that contactless contactor processed cooperates DC-DC circuit respective switch pipe that its work is made to realize energy storage device in BOOST state,
Supplement the deficiency of photovoltaic power generation；The end voltage of microprocessor real-time detection energy-storage battery simultaneously, when the end voltage for detecting battery
Lower than the minimum discharge voltage that it allows, then stop discharging；If battery discharge is not able to satisfy loading demand still, insufficient electric energy can
It is supplied by power grid.
The microprocessor both can by man-machine interface realize information exchange, can with real-time detecting system relevant parameter,
Adjusting corresponding device manually or automatically cut-offs the charge and discharge control for realizing energy-storage battery unit；Also telecommunication circuit can be relied on
It realizes the real-time upload of data state info, realizes long-range monitoring.
The example of the utility model provides a kind of control of photovoltaic power station user side three-phase imbalance counter-flow-preventing device
Method processed, this method are as follows: design corresponding current detection circuit using Hall current sensor, detect inverter outlet side respectively
The three-phase electricity flow valuve i of balanced balanced current value i and load-sidej' (j=a, b, c), and corresponding current signal is sent to microprocessor；
The microprocessor internal carries out out-of-balance current analysis, is respectively specifically that threephase load electric current is done to inverter outlet side electric current
Difference calculates, difference ij=i-ij' (j=a, b, c), and by its difference ijIt is compared with zero, according to comparison result and ties
It closes the battery terminal voltage size detected and the corresponding turn on thyristors realization of rectification circuit is controlled by pulse-triggered driving circuit
Storage control to extra phase electricity is loaded, or by the realization of control contactor switch to the control of discharge of energy-storage battery.Institute
State what control method was mainly realized by microprocessor, the working principle of specific control system is as shown in Figure 3.
The photovoltaic power station user side three-phase imbalance counter-flow-preventing device, by load-side controllable device in parallel
Part and energy storage device are to solve laod unbalance current problems, for the energy storage device charge and discharge control state process of the system
Schematic diagram is as shown in figure 4, the parameter information arrived according to real-time detection is passed through such as inverter output current value, threephase load current value
It crosses to analyze in microprocessor internal and compare, obtain the charge and discharge control state of energy storage device under the conditions of different parameters.
The charge control for being decided whether to carry out energy-storage battery according to comparison result, specifically: microprocessor is examined in real time
Voltage and current relevant parameter is surveyed, when detecting inverter outlet side current value i and load-side three-phase current ij' (j=a, b, c)
Difference ijThere is the case where being greater than zero in (j=a, b, c), that is, there is ij> 0, then illustrate there is what needs stored in load-side three-phase
Extra electric energy.When detecting inverter outlet side current value i and load-side three-phase current ij' (j=a, b, c) difference ij(j=
A, b, c) in the case where being all larger than zero there are three-phase, i.e. ia> 0, ib> 0 and ic> 0, then illustrate that load-side three-phase electricity has residue, this
When scr rectification circuit need to complete the rectification of extra three-phase electricity, microprocessor is with inverter outlet side electric current and load-side three
Corresponding thyristor is controlled subject to the maximum phase of phase current difference opens the rectification and storage for completing each mutually extra electricity；When
Detect inverter outlet side current value i and load-side three-phase current ij' (j=a, b, c) difference ijIt is only deposited in (j=a, b, c)
The case where two-phase is greater than zero, i.e. ia> 0, ib> 0 and ic≦0、ia> 0, ic> 0 and ib≤ 0 or ib> 0, ic> 0 and ia≤ 0, explanation
Load-side has two-phase electric energy to have residue, and microprocessor is with inverter outlet side electric current and load-side three-phase current difference maximum one
Another extra corresponding thyristor is controlled subject to phase opens the rectification and storage for completing extra phase electricity；When detecting inverter
Outlet side current value i and load-side three-phase current ij' (j=a, b, c) difference ijA phase is only existed in (j=a, b, c) greater than zero
The case where, i.e. ia> 0, ib≤ 0 and ic≦0、ib> 0, ia≤ 0 and ic≤ 0 or ic> 0, ia≤ 0 and ib≤ 0, illustrate that load-side only has
One phase electric energy has residue, and microprocessor is by controlling the extra corresponding turn on thyristors of phase current, remaining corresponding brilliant lock
Pipe cooperates the thyristor of the extra phase to complete the rectification and storage of extra phase electric energy.Microprocessor real-time detection energy-storage battery simultaneously
End voltage Uc, when detecting the end voltage of battery in the chargeable range of permission, microprocessor, which controls corresponding switching tube, to be made
DC-DC circuit work is in decompression charged state；When microprocessor detects the end voltage U of batterycIt is filled beyond its maximum allowed
Piezoelectric voltage Umax, then stop charging.
The control of discharge for being decided whether to carry out energy-storage battery according to comparison result, specifically: microprocessor is examined in real time
Voltage and current relevant parameter is surveyed, when detecting inverter outlet side current value i and load-side three-phase current ij' (j=a, b, c)
Difference ijThe case where (j=a, b, c) is greater than zero there is no any phase, i.e. ia≤ 0, ib≤ 0 and ic≤ 0, illustrate photovoltaic power generation not
It is enough to use for load, microprocessor control contactor switch and DC-DC circuit respective switch pipe are rising its work at this time
Electricity condition is pressed, realizes to the control of discharge of energy-storage battery, supplements the deficiency of photovoltaic power generation；Microprocessor real-time detection storage simultaneously
The end voltage U of energy batteryc, when the end voltage for detecting battery is lower than its minimum discharge voltage U allowedmin, then stop discharging；
If battery discharge is not able to satisfy loading demand still, insufficient electric energy can be supplied by power grid.
The situation being likely to occur:
(1) load-side three-phase current has residue
The three phase unbalance current i of three-phase equilibrium electric current i, load-side that microprocessor real-time detection inverter exportsj’(j
=a, b, c) and energy-storage battery end voltage Uc, then calculate inverter outlet side current value i and load-side three-phase current ij’
The difference i of (j=a, b, c)j(j=a, b, c), and its size of the difference is compared with zero, if difference ijIn (j=a, b, c)
The case where being all larger than zero there are three-phase, i.e. ia> 0, ib> 0 and ic> 0, then illustrate that load-side three-phase electricity has residue, at this time thyristor
Rectification circuit needs to complete the rectification of extra three-phase electricity, and microprocessor is poor with inverter outlet side electric current and load-side three-phase current
Be worth control corresponding thyristor subject to a maximum phase open the rectification and storage for completing each mutually extra electricity.
For said circumstances, inverter outlet side electric current and load-side three-phase current are made the difference calculating respectively by microprocessor,
The charge value that its difference needs to store as exchange side, i.e. A phase can store ia=i-ia', B phase can store ib=i-ib', C
It mutually can store ic=i-ic', and be subject to the maximum phase of difference and control opening for corresponding thyristor and complete each mutually extra electricity
The rectification of amount；If the difference of A phase is maximum, i.e. ia=imax=max [ia,ib,ic], then passed through first according to the polarity of A phase current
A corresponding thyristor VT1 or VT4 conducting is triggered, successively successively triggers crystalline substance according to the turn-on sequence of three phase controlled rectifier circuit
Three phase rectifier is completed in brake tube conducting, and is controlled its work in conjunction with DC-DC circuit and realized in the case where being depressured charge mode to energy-storage battery
Charge control.The end voltage U of microprocessor real-time detection energy-storage battery simultaneouslyc, when detecting battery terminal voltage UcPermit beyond it
Perhaps maximum charging voltage Umax, i.e. Uc>Umax, then stop charging.
(2) any biphase current of load-side has residue
The three phase unbalance current i of three-phase equilibrium electric current i, load-side that microprocessor real-time detection inverter exportsj’(j
=a, b, c) and energy-storage battery end voltage Uc, then calculate inverter outlet side current value i and load-side three-phase current ij’
The difference i of (j=a, b, c)j(j=a, b, c), and its size of the difference is compared with zero, if difference ijIn (j=a, b, c)
Only exist the case where two-phase is greater than zero, i.e. ia> 0, ib> 0, ic≤ 0 or ia> 0, ic> 0, ib≤ 0 or ib> 0, ic> 0, ia≤ 0,
Illustrate that load-side has two-phase electric energy to have residue, microprocessor is maximum with inverter outlet side electric current and load-side three-phase current difference
A phase subject to control another extra corresponding thyristor and open the rectification and storage for completing extra phase electricity；
For said circumstances, it is assumed that ib> 0, ic> 0, ia≤ 0, i.e. B, C biphase current has residue, and microprocessor respectively will be inverse
Become device outlet side electric current and load-side B, C biphase current and make the difference calculatings, difference is as the charge value for exchanging side needs and storing, i.e.,
B phase can store i-ib', C phase can store i-ic', and be subject to the maximum phase of difference and control the open-minded of corresponding thyristor
Complete the rectification of the extra electricity of two-phase；If the difference of B phase is maximum, need to be connected according to the judgement of the polarity of B phase current first
Thyristor, when the work of B phase current is in positive half cycle, successively triggering VT3, VT2 realizes rectification；When B phase current works in negative half period
When, it successively triggers VT6, VT5 and realizes rectification；It combines DC-DC circuit to control the work of its switching tube while rectification to charge in decompression
Realize extra phase electric energy to the charge control of energy-storage battery under mode.The end voltage of microprocessor real-time detection energy-storage battery simultaneously
Uc, when detecting battery terminal voltage UcThe maximum charging voltage U allowed beyond itmax, i.e. Uc>Umax, then stop charging.
(3) any one phase current of load-side has residue
The three phase unbalance current i of three-phase equilibrium electric current i, load-side that microprocessor real-time detection inverter exportsj’(j
=a, b, c) and energy-storage battery end voltage Uc, then calculate inverter outlet side current value i and load-side three-phase current ij’
The difference i of (j=a, b, c)j(j=a, b, c), and its size of the difference is compared with zero, if difference ijIn (j=a, b, c)
Only exist a case where phase is greater than zero, i.e. ia> 0, ib≤ 0 and ic≦0、ib> 0, ia≤ 0 and ic≤ 0 or ic> 0, ia≤ 0 and ib≦
0, illustrate that load-side only has a phase electric energy to have residue, microprocessor, which passes through, controls the extra corresponding turn on thyristors of phase current,
Remaining corresponding thyristor cooperates the thyristor of the extra phase to complete the rectification and storage of extra phase electric energy.
For said circumstances, it is assumed that ic> 0, ia≤ 0 and ib≤ 0, i.e. load-side C phase current has residue, and microprocessor then needs
The storage of the extra electric energy of C phase is completed, microprocessor triggers corresponding thyristor VT5 or VT2 according to the polarity of C phase current first
Conducting, remaining corresponding thyristor cooperate the thyristor of the extra phase complete extra phase electric energy rectification control, rectification it is same
When so that its work is realized the charge control to energy-storage battery in the case where being depressured charge mode in conjunction with DC-DC circuit.Microprocessor simultaneously
The end voltage U of real-time detection energy-storage batteryc, when detecting battery terminal voltage UcThe maximum charging voltage U allowed beyond itmax, i.e.,
Uc>Umax, then stop charging.
(4) photovoltaic power generation is not enough to use for threephase load
Microprocessor real-time detection relevant parameter, when detecting inverter outlet side current value i and load-side three-phase current
ij' (j=a, b, c) difference ijThe case where (j=a, b, c) is greater than zero there is no any phase, i.e. ia≤ 0, ib≤ 0, ic≤ 0,
Illustrate that photovoltaic power generation is not enough to use for load, at this time microprocessor control contactor switch and DC-DC circuit respective switch
Pipe makes its work in step-up discharge state, realizes to the control of discharge of energy-storage battery, supplements the deficiency of photovoltaic power generation.
For said circumstances, it is assumed that ic< 0, ia< 0 and ib< 0, i.e. photovoltaic power generation has not load-side A, B, C three-phase
Foot, microprocessor control contactor switch and DC-DC circuit respective switch pipe make its work in step-up discharge state at this time, in fact
Now to the control of discharge of energy-storage battery, to supplement the deficiency of photovoltaic power generation.The end of microprocessor real-time detection energy-storage battery simultaneously
Voltage Uc, when the end voltage for detecting battery is lower than its minimum discharge voltage U allowedmin, then stop discharging；If battery discharge
It is not able to satisfy loading demand still, then insufficient electric energy can be supplied by power grid.
The example of the utility model is directed to the work that the situation analysis of one of the situation being likely to occur illustrates the control method
Principle specifically assumes that load-side A, B, C three-phase have residue respectively；Load-side B, C two-phase has residue；Load-side C phase has surplus
Remaining and load-side A, B, C three-phase has insufficient situation expansion explanation, and the treating method of remaining various situation is similar.
Microprocessor by continuous real-time detection, analytical judgment, can realize that the auto charge and discharge of system controls to adjust, effective anti-
The only reflux problem of the extra phase current of load-side.
The embodiments of the present invention are described in conjunction with attached drawing above, only the embodiments of the present invention, and
The scope of patent protection of non-limiting the utility model.Those skilled in the art are done direct using the content of the present specification
Or indirect conversion is used in correlative technology field, belongs to the column of scope of protection of the utility model.
Claims (6)
1. a kind of photovoltaic power station user side three-phase imbalance counter-flow-preventing device, which is characterized in that including with distribution
Rectified three-phase circuit, bidirectional DC-DC converter circuit, energy-storage battery and the microprocessor of photovoltaic plant load-side parallel connection；Described point
Cloth photovoltaic plant exports three-phase equilibrium alternating current through inverter and loads use for low-voltage customer；The rectified three-phase circuit goes out
Line end successively connects and composes the charging major loop of out-of-balance current with bi-directional DC-DC circuit, energy-storage battery；Rectified three-phase circuit
Leading-out terminal is connect with the end of incoming cables of inverter by contactless contactor simultaneously, forms battery discharge circuit；The microprocessor
It connect with detection module, for detecting the three-phase electricity flow valuve of inverter outlet side current value and load-side respectively, and then drives
The switching tube of rectification circuit thyristor, contactless contactor and DC-DC circuit.
2. photovoltaic power station user side three-phase imbalance counter-flow-preventing device according to claim 1, feature exist
In the rectified three-phase circuit is made of six thyristors, wherein thyristor VT1 and thyristor VT4, thyristor VT3 and brilliant lock
Pipe VT6 and thyristor VT5 and thyristor VT2 respectively constitute three groups of upper and lower bridge arms, two arm alternating conductives up and down of same half-bridge.
3. photovoltaic power station user side three-phase imbalance counter-flow-preventing device according to claim 1, feature exist
In the bi-directional DC-DC circuit is formed by BUCK circuit and BOOST circuit inverse parallel.
4. photovoltaic power station user side three-phase imbalance counter-flow-preventing device according to claim 1, feature exist
In the battery energy storage unit is nickel hydrogen storage battery, lithium-ions battery or fuel cell.
5. photovoltaic power station user side three-phase imbalance counter-flow-preventing device according to claim 1, feature exist
In, it further include detection circuit, the three-phase equilibrium that the output end of the detection circuit connection inverter is exported for detecting inverter
The input terminal of electric current, detection circuit connection load is used to detect the three phase unbalance current of load-side, and detection circuit connects energy storage
Battery is for detecting its end voltage.
6. photovoltaic power station user side three-phase imbalance counter-flow-preventing device according to claim 1, feature exist
In the microprocessor is connect with man-machine interface, or is connect by telecommunication circuit with remote monitoring system.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821106707.0U CN208386163U (en) | 2018-07-12 | 2018-07-12 | Photovoltaic power station user side three-phase imbalance counter-flow-preventing device |
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|---|---|---|---|
| CN201821106707.0U CN208386163U (en) | 2018-07-12 | 2018-07-12 | Photovoltaic power station user side three-phase imbalance counter-flow-preventing device |
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| CN208386163U true CN208386163U (en) | 2019-01-15 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108616135A (en) * | 2018-07-12 | 2018-10-02 | 陕西科技大学 | Photovoltaic power station user side three-phase imbalance counter-flow-preventing device and method |
| CN115954902A (en) * | 2023-03-08 | 2023-04-11 | 杭州芯云半导体技术有限公司 | Device and method for eliminating three-phase load unbalance of semiconductor test equipment |
-
2018
- 2018-07-12 CN CN201821106707.0U patent/CN208386163U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108616135A (en) * | 2018-07-12 | 2018-10-02 | 陕西科技大学 | Photovoltaic power station user side three-phase imbalance counter-flow-preventing device and method |
| CN108616135B (en) * | 2018-07-12 | 2023-11-24 | 陕西科技大学 | Device and method for preventing three-phase imbalance countercurrent of user side of distributed photovoltaic power station |
| CN115954902A (en) * | 2023-03-08 | 2023-04-11 | 杭州芯云半导体技术有限公司 | Device and method for eliminating three-phase load unbalance of semiconductor test equipment |
| CN115954902B (en) * | 2023-03-08 | 2023-05-16 | 杭州芯云半导体技术有限公司 | Device and method for eliminating three-phase load unbalance of semiconductor test equipment |
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