CN207543061U - A kind of DC switchgear and photovoltaic generating system - Google Patents
A kind of DC switchgear and photovoltaic generating system Download PDFInfo
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- CN207543061U CN207543061U CN201721082408.3U CN201721082408U CN207543061U CN 207543061 U CN207543061 U CN 207543061U CN 201721082408 U CN201721082408 U CN 201721082408U CN 207543061 U CN207543061 U CN 207543061U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- 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
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Abstract
The utility model provides a kind of DC switchgear and photovoltaic generating system, pass through the input terminal voltage and output end voltage of voltage detection unit acquisition switch, then control unit receives the input terminal voltage and output end voltage of switch, judge whether the output end voltage of the input terminal voltage and switch of switch meets the first preset relation, if, generate switch close command, so that switch is closed, if not, generate voltage regulating command, with the input terminal voltage and output end voltage of regulating switch, until the input terminal voltage of switch and the output end voltage of switch meet the first preset relation.It can be seen that, this programme is by comparing switch input terminal and the voltage of output terminal, when input voltage and output voltage meet preset condition, combined floodgate work could be triggered, it is avoided from root since switch input terminal and output end voltage difference are excessive, heavy current impact damage device is led to the problem of when closing a floodgate, improves the reliability of photovoltaic generating system.
Description
Technical field
The utility model is related to field of photovoltaic power generation more particularly to a kind of DC switchgears and photovoltaic generating system.
Background technology
With the continuous development of society, photovoltaic generation has obtained quick development, in general, in photovoltaic generating system, it is more
A photovoltaic module is combined by connection in series-parallel, the photovoltaic module array with high current or voltage is formed, then using direct current
Switching device is connected to the DC side of photovoltaic DC-to-AC converter, and the converting direct-current power into alternating-current power after summarizing is transported to by photovoltaic DC-to-AC converter
In power grid.
At present, DC switchgear needs to carry out closing by hand, however, before combined floodgate, the voltage of photovoltaic module array
Different from the input terminal voltage of inverter direct-flow side, also, the capacitance of inverter dc bus is larger, therefore, when combined floodgate, can go out
Existing larger rush of current and the impact of dc loop circuit resonance potential, can cause to close a floodgate fails, and results even in DC fuse and melts
Disconnected, DC capacitor and other device overcurrent damages.
Therefore, how a kind of DC switchgear is provided, the over-current shock when closing a floodgate can be avoided to burn device, be this
A field technology personnel big technical barrier urgently to be resolved hurrily.
Utility model content
In view of this, the utility model provides a kind of DC switchgear and photovoltaic generating system, can avoid
Over-current shock is big during combined floodgate, burns the phenomenon that device, improves the reliability of photovoltaic generating system.
In view of this, the utility model provides a kind of DC switchgear, including：
Switch, described switch one end are connected with photovoltaic array, and the other end is connected with the DC side of photovoltaic DC-to-AC converter；
Voltage detection unit, the voltage detection unit are connected with the switch, acquire the input terminal voltage of the switch
And output end voltage,
Control unit is connected with the voltage detection unit, receives the input terminal voltage of the switch and output terminal electricity
Pressure, judges whether the input terminal voltage of the switch meets the first preset relation with the output end voltage of the switch, if so,
Switch close command is generated, so that the switch is closed, if not, voltage regulating command is generated, to adjust the defeated of the switch
Enter terminal voltage and output end voltage, until the output end voltage of input terminal voltage and the switch of the switch meet it is described
First preset relation.
Optionally, the voltage detection unit includes：
Input voltage measurement unit, the input voltage measurement unit is connected with the input terminal of the switch, described in acquisition
The input terminal voltage of switch；
Output voltage detection unit, the output voltage detection unit is connected with the output terminal of the switch, described in acquisition
The output end voltage of switch.
Optionally, when the switch is electric-controlled switch, the control terminal of the electric-controlled switch and described control unit it is defeated
Outlet is connected, and receives the switch close command, and the electric-controlled switch is controlled to perform closed action；
When the switch is mechanical switch, further include instruction device, the instruction device and described control unit it is defeated
Outlet is connected, and receives the switch close command, generates indication signal.
Optionally, it further includes：
Voltage regulation unit, the voltage regulation unit are connected with the input terminal of described control unit, are arranged on described open
The input terminal or output terminal of pass or the both ends for being connected across the switch, receive the voltage regulating command, adjust the switch
Input terminal voltage and/or output end voltage so that the input terminal voltage of the switch and the output end voltage of the switch are expired
Foot first preset relation.
Optionally, the voltage regulation unit is switched including at least one, and voltage regulation unit is adjusted certainly by switching
The output voltage of body.
Optionally, when the voltage regulation unit is arranged on the input terminal of the switch, in the input terminal of the switch
Photovoltaic array at least 1 piece of photovoltaic module on voltage regulation unit is set, the output terminal of the voltage regulation unit and its
The output terminal of his photovoltaic module or voltage regulation unit is connected in series with, and is formed after photovoltaic string formation and is connected to the input of the switch
End.
Optionally, it further includes：
Communication unit, the communication unit is communicated to connect with the switch or the voltage regulation unit, by the switch
Close command or the voltage regulating command are sent to the switch or the voltage regulation unit.
Optionally, first preset relation includes：
The input terminal voltage of the switch and the absolute value of the difference of the output end voltage of the switch are less than or equal to first
Predetermined threshold value voltage；
Or,
The input terminal voltage of the switch not higher than the second predetermined threshold value voltage and/or, the output end voltage of the switch
Not higher than third predetermined threshold value voltage；
Or,
The voltage of equivalent smaller one end of shunt capacitance is not in the input terminal voltage of the switch and the output end voltage
The voltage of one end larger less than equivalent parallel capacitance.
A kind of photovoltaic generating system, including the above-mentioned DC switchgear of any one.
Optionally, it further includes：
Direct current conflux case, the direct current conflux case are connected with photovoltaic module array, the output to the photovoltaic module array
Electric current converges, and the DC switchgear is integrated in direct current conflux case.
By said program it is found that the utility model provides a kind of DC switchgear, including：Switch, voltage detecting list
Member and control unit, wherein, described switch one end is connected with photovoltaic array, the DC side phase of the other end and photovoltaic DC-to-AC converter
Even.Voltage detection unit is connected with the switch, acquires the input terminal voltage and output end voltage of the switch.Control unit
It is connected with the voltage detection unit, receives the input terminal voltage and output end voltage of the switch, judge the switch
Whether the output end voltage of input terminal voltage and the switch meets the first preset relation, if so, switch close command is generated,
So that the switch is closed, if not, voltage regulating command is generated, to adjust the input terminal voltage of the switch and output terminal
Voltage, until the input terminal voltage of the switch and the output end voltage of the switch meet first preset relation.As it can be seen that
This programme is by comparing switch input terminal and the voltage of output terminal, when input voltage meets preset condition with output voltage,
Combined floodgate work can be triggered, is avoided from root since switch input terminal and output end voltage difference are excessive, is generated when closing a floodgate
Heavy current impact damages the problem of device, improves the reliability of photovoltaic generating system.
Description of the drawings
It in order to illustrate the embodiment of the utility model or the technical proposal in the existing technology more clearly, below will be to embodiment
Or attached drawing needed to be used in the description of the prior art is briefly described, it should be apparent that, the accompanying drawings in the following description is only
It is some embodiments of the utility model, for those of ordinary skill in the art, in the premise not made the creative labor
Under, it can also be obtained according to these attached drawings other attached drawings.
Fig. 1 is a kind of structure diagram of DC switchgear provided by the utility model；
Fig. 2 is a kind of another structure diagram of DC switchgear provided by the utility model；
Fig. 3 is a kind of another structure diagram of DC switchgear provided by the utility model；
Fig. 4 is a kind of another structure diagram of DC switchgear provided by the utility model；
Fig. 5 is a kind of another structure diagram of DC switchgear provided by the utility model；
Fig. 6 is a kind of another structure diagram of DC switchgear provided by the utility model；
Fig. 7 is a kind of another structure diagram of DC switchgear provided by the utility model；
Fig. 8 is a kind of another structure diagram of DC switchgear provided by the utility model；
Fig. 9 is a kind of another structure diagram of DC switchgear provided by the utility model；
Figure 10 is a kind of equivalent capacity figure of DC switchgear provided by the utility model；
Figure 11 is the combined floodgate resonant voltage waveforms figure of Traditional DC switching device；
Figure 12 is the another combined floodgate resonant voltage waveforms figure of Traditional DC switching device.
Specific embodiment
The following is a combination of the drawings in the embodiments of the present utility model, and the technical scheme in the embodiment of the utility model is carried out
It clearly and completely describes, it is clear that the described embodiments are only a part of the embodiments of the utility model rather than whole
Embodiment.Based on the embodiment in the utility model, those of ordinary skill in the art are without making creative work
All other embodiments obtained shall fall within the protection scope of the present invention.
Referring to Fig. 1, Fig. 1 is the structure diagram of a kind of DC switchgear that the utility model embodiment provides,
In, which includes switch, voltage detection unit and control unit.
Specifically, described switch one end is connected with photovoltaic array, the other end is connected with the DC side of photovoltaic DC-to-AC converter.It is described
Voltage detection unit is connected with the switch, acquires the input terminal voltage and output end voltage of the switch.Control unit with
The voltage detection unit is connected, and receives the input terminal voltage and output end voltage of the switch, judges the defeated of the switch
Enter terminal voltage and whether the output end voltage of the switch meets the first preset relation, if so, switch close command is generated, with
It is closed the switch, if not, voltage regulating command is generated, to adjust the input terminal voltage of the switch and output terminal electricity
Pressure, until the input terminal voltage of the switch and the output end voltage of the switch meet first preset relation.
In the present embodiment, the voltage detection unit can include input voltage measurement unit and output voltage detects
Unit, wherein, input voltage measurement unit is connected with the input terminal of the switch, acquires the input terminal voltage of the switch.It is defeated
The output terminal for going out voltage detection unit with the switch is connected, and acquires the output end voltage of the switch.
Specifically, the first preset relation can include：
The input terminal voltage of the switch and the absolute value of the difference of the output end voltage of the switch are less than or equal to first
Predetermined threshold value voltage；
Or,
The input terminal voltage of the switch not higher than the second predetermined threshold value voltage and/or, the output end voltage of the switch
Not higher than third predetermined threshold value voltage；
Or,
The voltage of equivalent smaller one end of shunt capacitance is not in the input terminal voltage of the switch and the output end voltage
The voltage of one end larger less than equivalent parallel capacitance.
Schematically, the inhibition that this programme provides is closed a floodgate the DC switchgear of impact, comprising a double-pole single throw,
1 input voltage measurement unit, 1 output voltage detection unit and 1 control unit.Input voltage measurement unit is used to detect
Switch input terminal voltage, output voltage detection unit are used for detection switch output end voltage, the input terminal voltage signal Vin of detection
It is sent into control unit with output end voltage signal Vout.Control unit judges whether Vin and Vout meets default adjusting, example
Such as, judge | Vin-Vout | whether≤Vth is true, and wherein Vth is preset threshold voltage, if so, it then sends out switch and is closed
Sig_dsp is instructed, if not, voltage regulating command Sig_ctl is then sent out, until | Vin-Vout | after≤Vth is set up, then
Send out switch close command Sig_dsp.
Different according to the triggering mode of switch except this, switch can be divided into electric-controlled switch and machinery in the present embodiment
Switch, wherein, as shown in Fig. 2, when the switch is electric-controlled switch, the control terminal and described control unit of the electric-controlled switch
Output terminal be connected, receive the switch close command, and the electric-controlled switch is controlled to perform closed action.As shown in figure 3, work as
When the switch is mechanical switch, instruction device is further included, the instruction device is connected with the output terminal of described control unit, connects
The switch close command is received, generates indication signal.
Specifically, when switching as electric-controlled switch, such as electric operating switch of relay, contactor, translator etc., control
The pass close command Sig_dsp that unit is sent out is used directly for control switch and is closed.
If switch is mechanical switch, need to be manually operated, for example, breaker, air switch etc., then control unit is sent out
Pass close command Sig_dsp can also be indicated by instruction device, can be closed with prompt switch.Such as buzzer hair
Go out sound, indicator light sends out illumination, liquid crystal display or the display devices such as numeral method character or symbol, can be closed with prompt switch
It closes.
On the basis of above-described embodiment, as shown in figure 4, DC switchgear provided in this embodiment further includes voltage tune
Unit is saved, which is connected with the input terminal of described control unit, is arranged on input terminal or the output of the switch
End, receives the voltage regulating command, adjusts the input terminal voltage and/or output end voltage of the switch, so that the switch
The output end voltage of input terminal voltage and the switch meet first preset relation.
Wherein, the voltage regulation unit includes Buck circuits, Buckboost circuits, flyback circuits or linear transformation
Device.
Specifically, when control unit judges that input terminal voltage signal Vin and output end voltage signal Vout are unsatisfactory for presetting
During condition, voltage regulating command Sig_ctl is sent out, for adjusting the output voltage of voltage regulation unit, so that Vin and Vout expire
Sufficient preset condition.
Voltage regulation unit can also be arranged on the output terminal of dc switch or input terminal is respectively provided with output terminal.Electricity
Pressure adjusts unit to be represented with the DC/DC converters of a Boost type in figure, other have the circuit for adjusting voltage function
, such as other kinds of DC/DC converters such as Buck, Buckboost, flyback, linear quantizer etc..
As shown in figure 5, voltage regulation unit can also use the pre-charge circuit with current-limiting function, it is connected across dc switch
Both ends.Pre-charge circuit in figure is connected by auxiliary switch and current-limiting resistance to be formed, when control unit judges input terminal voltage
When signal Vin and output end voltage signal Vout are unsatisfactory for preset condition, voltage regulating command Sig_ctl, control auxiliary are sent out
Switch is closed, and the input terminal and output terminal of dc switch form electric discharge loop by current-limiting resistance and auxiliary switch, finally make defeated
Enter terminal voltage signal Vin and output end voltage signal Vout meets preset condition.
As shown in fig. 6, voltage regulation unit can also be arranged in the photovoltaic array of DC switchgear input terminal, specifically
To set voltage regulation unit at least one photovoltaic module of photovoltaic array, the output terminal of voltage regulation unit is with other light
Component or the output terminal series connection of other voltage regulation units are lied prostrate, then accesses the input terminal of dc switch.It is arranged on photovoltaic module
On voltage regulation unit can be realized with the power optimization device with MPPT maximum power point tracking function, can also use only realize a component
The switch of turn-off function is realized.
It should be noted that voltage regulation unit may be multiple series-parallel forms, adjusted with reducing single voltage
The power of unit realizes the control more to become more meticulous.For example, there are switch input terminal 16 photovoltaic string formations to input, every 2 string formations
Switch input terminal is intervened again after 1 voltage regulation unit of connection, then needs 8 voltage regulation units, each voltage regulation unit
Output in switch input terminal parallel connection, each voltage regulation unit can adjust 2 photovoltaic string formations；If every 1 string formation connects 1
Switch input terminal is intervened after voltage regulation unit again, then needs 16 voltage regulation units, each voltage regulation unit can be adjusted
Save 1 photovoltaic string formation.
As shown in fig. 7, when photovoltaic array has multiple string formations, it can be in switch input terminal parallel connection；As shown in figure 8,
Can be in parallel again after multigroup switch, it needs to set the input voltage measurement list identical with switching group number in input terminal at this time
Whether member, every group of switch can reach preset condition to determine whether individually to close according to respective input voltage and output voltage
It closes, can also whether preset condition be reached according to the input voltage and output voltage of wherein at least one group switch determine whether can
With whole closures.
Except this, as shown in figure 9, DC switchgear provided in this embodiment, further includes communication unit, the communication unit
It is connected with the switch or the voltage regulation unit, the switch close command or the voltage regulating command is sent to institute
State switch or the voltage regulation unit.
Schematically, in the present embodiment, DC switchgear includes 2 communication units, for by voltage regulating command and
Switch close command is sent to external other equipment.It is PLC (power line carrier) communication unit to send voltage regulating command,
Voltage regulating command is sent to the electronic power conversions devices such as external power optimization device, inverter.It sends switch and is closed and refer to
Order is bluetooth-communication unit, is closely connect and communicated with man-hour manually hand-held equipment (such as smart mobile phone, removable computer),
Display can be with the instruction of closure switch, with operating personnel is notified to carry out closing operation on a handheld device.
Certainly, 2 communication devices can be combined into one, and can also only retain 1, and specific communication unit does not also limit to
In plc communication and Bluetooth communication, the communication mode being connect with PERCOM peripheral communication can be realized, such as RS485, CAN,
Zigbee, WIFI, GPRS, 3G, 4G etc..
As described in background, switch input side connection photovoltaic array, outlet side connection photovoltaic DC-to-AC converter dc bus.
Photovoltaic array has the capacitance that the equipment such as semiconductor junction capacitance, other parasitic capacitances and installation power optimizer introduce, photovoltaic
Inverter dc bus equally has larger capacitance.Inventor has found, when the capacitance voltage of switch ends is inconsistent, closes a floodgate
Larger rush of current is inevitably resulted in, and will be led since there are inductance or cable parasitic inductances, LC series resonances in loop
Cause larger voltage overshoot.The impact of electric current and voltage can influence the operational reliability of photovoltaic system.For example, dash current is excessive
Tripping after switch closes a floodgate is may result in, results in the need for reclosing；Or the overcurrent protection of the equipment in triggering dc loop circuit, example
Inverter direct current overcurrent protection is such as triggered, influences inverter normal operation.
String formation fuse is usually 15A specifications in photovoltaic system, and rush of current is more than that 20A may result in fuse failure；It crosses
High voltge surge can also be in reduction system capacitance, semiconductor devices etc. reliability, when serious can breakdown potential perhaps partly lead
Body device.
In the present solution, control unit judges whether input terminal voltage signal and output end voltage signal meet preset condition,
Switch close command only can be just sent out when meeting preset condition.Closure switch can be greatly reduced after preset condition is met
Even eliminate the impact of electric current and resonance potential.
One of which preset condition is：Difference between the input terminal voltage and output end voltage of switch is the first of setting
In threshold range, then the energy for impact of closing a floodgate can be limited in relatively low range, reduce combined floodgate surge voltage and electric current.
For example, output switching terminal connects photovoltaic DC-to-AC converter, output end voltage Vout=800V, input terminal connection photovoltaic array, input terminal
Voltage Vin=0V, photovoltaic DC-to-AC converter dc-link capacitance C1=5000uF, photovoltaic array side equivalent capacity C2=10uF, it is assumed that
Photovoltaic array lateral capacitance is full of by bus capacitor in a short time after combined floodgate, then the ceiling capacity for impact of closing a floodgate is
By setting Vth as 20V, then control unit control Vin boosts to 780V, then the ceiling capacity for impact of closing a floodgate is
W2=0.5*0.0001*8002-0.5*0.00001*7802=0.158J
Combined floodgate impact energy only has original 0.158/3.2*100%=4.9%, thus surge voltage can be greatly reduced
And electric current.
Another preset condition is：The input terminal voltage of switch is not higher than the second threshold of setting, the output of the switch
Terminal voltage is not higher than the third threshold value of setting.By controlling the voltage of switch ends, not higher than respective settings value, then both sides are electric
The energy for storing storage is smaller, therefore impact energy is also small during combined floodgate, so as to reduce combined floodgate surge voltage and electric current.Such as it opens
Output terminal connection photovoltaic DC-to-AC converter, input terminal connection photovoltaic array are closed, the photovoltaic module in photovoltaic array is equipped with DC/DC transformation
Device (is used to carry out MPPT maximum power point tracking, commonly referred to as power optimization device to component), photovoltaic DC-to-AC converter dc-link capacitance C1
=5000uF, photovoltaic array side equivalent capacity C2=10uF, it is 100V to set second threshold and third threshold value, current switch
Output terminal photovoltaic DC-to-AC converter DC voltage Vout=0V, switch input terminal photovoltaic array output voltage Vin=800V, it is assumed that close a floodgate
Photovoltaic array lateral capacitance is discharged to 0V in a short time afterwards, then the ceiling capacity for impact of closing a floodgate is
W1=0.5*0.0001*8002=3.2J
If control unit control photovoltaic array is depressured within second threshold 100V, the ceiling capacity for impact of closing a floodgate is
W2=0.5*0.00001*1002=0.05J
Combined floodgate impact energy only has original 0.05/3.2*100%=1.6%, thus surge voltage can be greatly reduced
And electric current.
Another preset condition is：The voltage of equivalent smaller one end of shunt capacitance is not in the input terminal and output terminal of switch
The voltage of one end larger less than equivalent parallel capacitance.Switch be closed during, switch both sides capacitance can in loop
Inductance generate resonance, the mains ripple that resonant energy generates on small capacitances will necessarily be more than voltage arteries and veins on bulky capacitor
It is dynamic.Initial voltage before switch is closed on small capacitances then switchs the energy of resonance after being closed higher than the initial voltage on bulky capacitor
Amount can be extracted from small capacitances, and resonance potential carries out partial pressure by two capacitances and shares equally, and the voltage on small capacitances will not surpass always
Overvoltage initial value, the voltage on bulky capacitor can be more than initial voltage, but due to its larger resonance potential of capacity partial pressure not yet
It can be too big；The initial voltage before if switch is closed on small capacitances switchs the energy of resonance after being closed less than the voltage on bulky capacitor
Amount can be extracted from bulky capacitor, and the voltage on bulky capacitor does not exceed Initial Voltage Value, and the voltage on small capacitances can be more than initial
Voltage, and the partial pressure of larger resonance potential is born since capacity is smaller, small capacitances and its parallel connection may finally be caused
Equipment occur excessive pressure damages.Therefore, by controlling the voltage of the smaller one end of equivalent parallel capacitance not less than equivalent parallel electricity
Hold the voltage of larger one end, voltage overshoot endangers caused by can effectively reducing combined floodgate.
It is further illustrated below with a specific sample calculation, as shown in Figure 10, it is assumed that switch input terminal equivalent parallel electricity
Hold Cin=10uF, output terminal equivalent parallel capacitance Cout=5000uF, and inductance is only existed in hypothesis loop, resistance 0, very
LC series resonances can occur after closing a floodgate for apparent switch, and resonance potential peak value will be 2 times of Cin and Cout difference in voltage.
If Cin initial voltages are 800V, the initial voltage of Cout is 500V, then resonance potential peak value is 2* (800V-
500V)=600V, then it is 800V that the maximum voltage after closing a floodgate on Cin is switched at the t0 moment, and the maximum voltage on Cout is 500V
+600V*10uF/(5000uF+10uF)≈500V.It is practical to be damped due to existing in system, combined floodgate resonant voltage waveforms such as Figure 11
It is shown.
If Cin initial voltages are 500V, the initial voltage of Cout is 800V, then resonance potential peak value is 2* (800V-
500V)=600V, then it is 500V+600V*5000uF/ (5000uF+ that the maximum voltage after closing a floodgate on Cin is switched at the t0 moment
Maximum voltage on 10uF) ≈ 1100V, Cout is 800V.Practical to be damped due to existing in system, combined floodgate resonant voltage waveforms are such as
Shown in Figure 12.In this example, if photovoltaic system maximum voltage be 1000V, it is clear that the maximum voltage on Cin have been over be
System maximum voltage, therefore overvoltage harm can be generated to the equipment of capacitance and its parallel connection.
It is noted that the equivalent parallel capacitance of switch input terminal and output terminal is typically from：Photovoltaic DC-to-AC converter
The Switching Power Supply of electricity is taken in DC capacitor, the output capacitance of power optimization device of photovoltaic module installation, photovoltaic system from direct current
Input capacitance, other parasitic capacitances etc..
On the basis of above-described embodiment, the present embodiment additionally provides a kind of photovoltaic generating system, including such as any one
Above-mentioned DC switchgear.Except this, can also include：Direct current conflux case, the direct current conflux case and the photovoltaic module array
It is connected, converges to the output current of the photovoltaic module array.
Schematically, the photovoltaic system of a kind of impact that inhibits to close a floodgate provided in this embodiment, comprising DC switchgear and
Photovoltaic array.
As a kind of preferred embodiment, the input terminal connection photovoltaic array of DC switchgear, the photovoltaic array by
At least two photovoltaic module connection in series-parallel is formed.The series-parallel system of photovoltaic module in photovoltaic array is usually：Multiple photovoltaic modulies
(such as 20) series connection forms photovoltaic string formation, and then multiple photovoltaic string formations are connected in parallel to form photovoltaic array again.
As another preferred embodiment, the output terminal of one or more photovoltaic modulies in photovoltaic array is also connected with 1
Voltage regulation unit, the output terminal of voltage regulation unit form the photovoltaic array using connection in series-parallel, are connected to dc switch
The input terminal of device.In the present embodiment, each voltage regulation unit can receive the voltage tune of DC switchgear transmission
Section instruction, and the output voltage of itself is adjusted, and then be connected to switch input terminal after can controlling connection in series-parallel according to instruction
The output voltage of photovoltaic array.At least one should be included in order to realize the function of adjusting voltage, inside voltage regulation unit to switch
Device, such as MOSFET, IGBT, transistor, relay etc..
As a kind of preferred embodiment, 1 series switching devices is included inside voltage regulation unit, passes through and controls switch
The on, off of device periodically switchs to adjust the output voltage of itself.
As another preferred embodiment, comprising 1 switching device being connected in parallel inside voltage regulation unit, pass through
It controls the on, off of switching device or periodically switchs to adjust the output voltage of itself.In order to which paralleling switch is inhibited to lead
Logical electric current, can also connect on paralleling switch a current limiting device, such as resistance, inductance etc..
As another preferred embodiment, comprising 1 DC/DC converter inside voltage regulation unit, as buck,
The DC/DC converters such as boost, flyback, normal shock, half-bridge, LLC, phase-shifting full-bridge, linear quantizer are adjusted certainly by converter
The output voltage of body.
As another preferred embodiment, photovoltaic system is also comprising 1 photovoltaic DC-to-AC converter, the output of DC switchgear
The direct-flow input end of end connection photovoltaic DC-to-AC converter.The voltage adjusting that photovoltaic DC-to-AC converter can receive DC switchgear transmission refers to
It enables, and according to instruction come the DC voltage of regulating switch output terminal.
As another preferred embodiment, DC switchgear is integrated in photovoltaic DC-to-AC converter, is total to photovoltaic DC-to-AC converter
With a set of dc switch, shell mechanism etc., to improve the integrated level of photovoltaic system, and cost is reduced.
As another preferred embodiment, photovoltaic system is also comprising 1 direct current conflux case, for by the photovoltaic array
In multiple string formations converge, DC switchgear is integrated in direct current conflux case, and a set of direct current is shared with direct current conflux case
Switch, shell mechanism etc. to improve the integrated level of photovoltaic system, and reduce cost.
In summary：The utility model provides a kind of DC switchgear and photovoltaic generating system, passes through voltage detecting
The input terminal voltage and output end voltage of unit acquisition switch, then control unit receive the input terminal voltage and defeated of switch
Go out terminal voltage, judge whether the output end voltage of the input terminal voltage and switch of switch meets the first preset relation, if so, production
Raw switch close command so that switch is closed, if not, generate voltage regulating command, with the input terminal voltage of regulating switch with
And output end voltage, until the input terminal voltage of switch and the output end voltage of switch meet the first preset relation.It is as it can be seen that our
Case, when input voltage meets preset condition with output voltage, could be touched by comparing switch input terminal and the voltage of output terminal
Combined floodgate work is sent out, is avoided from root since switch input terminal and output end voltage difference are excessive, big electricity is generated when closing a floodgate
The problem of flowing impact failure device improves the reliability of photovoltaic generating system.
Each embodiment is described by the way of progressive in this specification, the highlights of each of the examples are with it is other
The difference of embodiment, just to refer each other for same or similar part between each embodiment.
The foregoing description of the disclosed embodiments enables professional and technical personnel in the field to realize or new using this practicality
Type.A variety of modifications of these embodiments will be apparent for those skilled in the art, determine herein
The General Principle of justice can be realized in other embodiments without departing from the spirit or scope of the present utility model.Cause
This, the utility model is not intended to be limited to the embodiments shown herein, and is to fit to and principles disclosed herein
The most wide range consistent with features of novelty.
Claims (10)
1. a kind of DC switchgear, which is characterized in that including：
Switch, described switch one end are connected with photovoltaic array, and the other end is connected with the DC side of photovoltaic DC-to-AC converter；
Voltage detection unit, the voltage detection unit with it is described switch be connected, acquire the switch input terminal voltage and
Output end voltage,
Control unit is connected with the voltage detection unit, receives the input terminal voltage and output end voltage of the switch, sentences
Whether the input terminal voltage of the switch that breaks meets the first preset relation with the output end voltage of the switch, if so, generating
Close command is switched, so that the switch is closed, if not, voltage regulating command is generated, to adjust the input terminal of the switch
Voltage and output end voltage, until the input terminal voltage of the switch and the output end voltage of the switch meet described first
Preset relation.
2. DC switchgear according to claim 1, which is characterized in that the voltage detection unit includes：
Input voltage measurement unit, the input voltage measurement unit are connected with the input terminal of the switch, acquire the switch
Input terminal voltage；
Output voltage detection unit, the output voltage detection unit are connected with the output terminal of the switch, acquire the switch
Output end voltage.
3. DC switchgear according to claim 2, which is characterized in that
When the switch is electric-controlled switch, the control terminal of the electric-controlled switch is connected with the output terminal of described control unit, connects
The switch close command is received, and the electric-controlled switch is controlled to perform closed action；
When the switch is mechanical switch, the output terminal of instruction device, the instruction device and described control unit is further included
It is connected, receives the switch close command, generates indication signal.
4. DC switchgear according to claim 2, which is characterized in that further include：
Voltage regulation unit, the voltage regulation unit are connected with the input terminal of described control unit, are arranged on the switch
Input terminal or output terminal or the both ends for being connected across the switch receive the voltage regulating command, adjust the defeated of the switch
Enter terminal voltage and/or output end voltage, so that the input terminal voltage of the switch and the output end voltage of the switch meet institute
State the first preset relation.
5. DC switchgear according to claim 4, which is characterized in that the voltage regulation unit includes at least one
Switch adjusts the output voltage of voltage regulation unit itself by switching.
6. DC switchgear according to claim 4, which is characterized in that described in being arranged on when the voltage regulation unit
During the input terminal of switch, voltage is set to adjust at least 1 piece of photovoltaic module in the photovoltaic array of the input terminal of the switch
Unit, the output terminal of the voltage regulation unit and the output terminal of other photovoltaic modulies or voltage regulation unit are connected in series with,
The input terminal of the switch is connected to after formation photovoltaic string formation.
7. DC switchgear according to claim 4, which is characterized in that further include：
Communication unit, the communication unit are communicated to connect with the switch or the voltage regulation unit, and the switch is closed
Instruction or the voltage regulating command are sent to the switch or the voltage regulation unit.
8. DC switchgear according to claim 4, which is characterized in that first preset relation includes：
It is default that the input terminal voltage of the switch and the absolute value of the difference of the output end voltage of the switch are less than or equal to first
Threshold voltage；
Or,
The input terminal voltage of the switch not higher than the second predetermined threshold value voltage and/or, the output end voltage of the switch is not high
In third predetermined threshold value voltage；
Or,
The voltage of equivalent smaller one end of shunt capacitance is not less than in the input terminal voltage of the switch and the output end voltage
The voltage of the larger one end of equivalent parallel capacitance.
9. a kind of photovoltaic generating system, which is characterized in that including the dc switch dress as described in any one in claim 1-8
It puts.
10. photovoltaic generating system according to claim 9, which is characterized in that further include：
Direct current conflux case, the direct current conflux case are connected with photovoltaic module array, to the output current of the photovoltaic module array
Converge, the DC switchgear is integrated in direct current conflux case.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721082408.3U CN207543061U (en) | 2017-08-25 | 2017-08-25 | A kind of DC switchgear and photovoltaic generating system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201721082408.3U CN207543061U (en) | 2017-08-25 | 2017-08-25 | A kind of DC switchgear and photovoltaic generating system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207543061U true CN207543061U (en) | 2018-06-26 |
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| CN201721082408.3U Active CN207543061U (en) | 2017-08-25 | 2017-08-25 | A kind of DC switchgear and photovoltaic generating system |
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| Country | Link |
|---|---|
| CN (1) | CN207543061U (en) |
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2017
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