CN206259694U - The protection device of inversion system - Google Patents
The protection device of inversion system Download PDFInfo
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- CN206259694U CN206259694U CN201621362560.2U CN201621362560U CN206259694U CN 206259694 U CN206259694 U CN 206259694U CN 201621362560 U CN201621362560 U CN 201621362560U CN 206259694 U CN206259694 U CN 206259694U
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- inversion system
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Abstract
The utility model provides a kind of protection device of inversion system.Including：Controller, and the AD sample circuits and digital output modul circuit being connected with controller respectively；AD sample circuits gather DC voltage, DC side electric current, AC voltage and the ac-side current of inversion system；Controller according to DC voltage, DC side electric current, AC voltage and the ac-side current for collecting, and setting power threshold and impedance threshold, it is determined whether send control signal；After the controller determines to send control signal, DC side breaker and AC breaker according to the control signal control inversion system for receiving disconnect digital output modul circuit.The utility model realizes the insulation impedance that can simply and rapidly obtain DC side, while being protected for inversion system provides security in time, reliably when breaking down.
Description
Technical field
The utility model is related to power electronics control technology field, more particularly to a kind of protection device of inversion system.
Background technology
In inversion system, easily broken down between DC side input.For example, short circuit between DC side input, it will produce
The larger immediate current of life, thus occurs damaging the danger such as component, fire.In the prior art, it is general by setting protection dress
Put to avoid the generation of above-mentioned danger.
Generally, existing protection device uses bridge measurement or leakage current sensor, respectively to input positive pole over the ground
Insulation impedance and input negative pole insulation impedance over the ground are detected, are carried out calculating acquisition direct current input according to the data for detecting
Insulation impedance between the both positive and negative polarity of side, and the alternating current-direct current breaker of control inverter disconnects on this basis, so as to realize to inverse
The protection of change system.
However, above-mentioned existing protection device has following weak point：One is exhausted between direct current input side both positive and negative polarity
The calculating process of edge impedance is complex；Two is the change speed degree due to being limited by the insulation impedance of DC side, for example,
In photovoltaic system, the DC side input of photovoltaic DC-to-AC converter is photovoltaic battery panel, even if cell panel there occurs short circuit, is produced larger
Immediate current, insulation impedance is reduced rapidly, and the short circuit current can not allow dc circuit breaker to disconnect；Thus, can not be in failure
When in time, reliably for inversion system provide security protect.
Utility model content
The purpose of the utility model embodiment is, there is provided a kind of protection device of inversion system, with realize can simply,
While rapidly obtaining the insulation impedance of DC side, as basis for estimation, so as to be in time, reliably when breaking down
Inversion system provides security protection.
To realize above-mentioned utility model purpose, the protection that embodiment of the present utility model provides a kind of inversion system is filled
Put, including：Controller, and the AD sample circuits and digital output modul circuit being connected with the controller respectively：The AD is adopted
Sample circuit is used to gather DC voltage, DC side electric current, AC voltage and the ac-side current of inversion system；The control
Device is used for according to the DC voltage, the DC side electric current, the AC voltage and AC electricity for collecting
Stream, and setting power threshold and impedance threshold, it is determined whether send control signal；The digital output modul circuit is used for
After the controller determines to send control signal, according to the DC side open circuit of the control signal control inversion system for receiving
Device and AC breaker disconnect.
Preferably, the controller is used for according to the DC voltage, the DC side electric current, the friendship for collecting
Stream side voltage and the ac-side current calculate the power difference between DC side and AC, and according to the power difference with
The power threshold and impedance threshold of the setting, it is determined whether send control signal.
Preferably, the controller is used for when power threshold of the power difference more than setting, according to the power
Difference and the DC voltage calculate the insulation impedance of DC side, also, when impedance threshold of the insulation impedance less than setting
When, it is determined that sending control signal.
Preferably, the controller is additionally operable to when power threshold of the power difference less than setting, or, when described
When power difference is more than the impedance threshold of setting more than the power threshold for setting, and the insulation impedance, it is determined that not sending control
Signal.
Preferably, the controller includes：AD control modules, calculating and judge module and the digital output being sequentially connected
Control module, the AD control modules are connected with the AD sample circuits, and the digital output control module is opened with described
Amount control circuit is closed to be connected.
Preferably, the controller also includes the fault alarm module being connected with the calculating and judge module.
Preferably, also including the display being connected with the fault alarm module and warning circuit, for showing the insulation
The value of impedance, and when the insulation impedance is less than impedance threshold, show that the DC side for characterizing the inversion system occurs
The warning message of failure.
Preferably, the controller is micro-control unit MCU or field programmable gate array FPGA.
The protection device of the inversion system that the utility model embodiment is provided, inversion system is gathered by AD sample circuits
DC voltage, DC side electric current, AC voltage and ac-side current, controller is according to the data and setting for collecting
Power threshold and impedance threshold, it is determined whether send control signal to digital output modul circuit, further it is determined that sending control
After signal, digital output modul circuit controls the DC side breaker and AC breaker of inversion system equal according to the control signal
Disconnect, while realizing the insulation impedance that can simply and rapidly obtain DC side, as basis for estimation, so as in hair
Protected for inversion system provides security in time, reliably during raw failure.
Brief description of the drawings
Fig. 1 is the structured flowchart of the protection device of the inversion system of the utility model embodiment one；For convenience of understanding, in figure
Show PV arrays, DC side breaker, DC side Support Capacitor, inverter, three pole reactor, AC relay, three-phase filtering
Electric capacity, AC breaker, transformer and power network；
The structured flowchart that Fig. 2 launches for controller in the protection device of the utility model embodiment two.
Drawing reference numeral explanation
S1- DC sides breaker, C- DC sides Support Capacitor, DC/AC- inverters, L1~L3- three pole reactors, R- exchanges
Relay, C1~C3- three-phases filter capacitor, S2- ACs breaker, 110- controllers, 120-AD sample circuits, 130- switches
Amount control circuit, 140- show and warning circuit, 210-AD control modules, 220- are calculated and judge module, 230- digital quantities are defeated
Go out control module, 240- fault alarm modules.
Specific embodiment
The protection device to the utility model embodiment inversion system is described in detail below in conjunction with the accompanying drawings.Hereinafter implement
Example is not limited to scope of the present utility model for illustrating the utility model.
It will be understood by those skilled in the art that the term such as " first ", " second " in the utility model embodiment is only used for
Difference different step, equipment or module etc., neither represent any particular technology implication, also do not indicate that the inevitable logic between them
Sequentially.
Embodiment one
Fig. 1 is the structured flowchart of the protection device of the inversion system of the utility model embodiment one.Reference picture 1, contravariant system
The protection device of system includes：Including controller 110, and the AD sample circuits 120 that are connected with controller 110 respectively and switching value
Control circuit 130；AD sample circuits 120 be used to gathering the DC voltage of inversion system, DC side electric current, AC voltage and
Ac-side current；Controller 110 is used for according to DC voltage, DC side electric current, AC voltage and the AC for collecting
Electric current, and setting power threshold and impedance threshold, it is determined whether send control signal；Digital output modul circuit 130 is used for
After controller 110 determines to send control signal, the DC side breaker of inversion system is controlled according to the control signal for receiving
Disconnected with AC breaker.
Further, controller 110 be used for according to collect DC voltage, DC side electric current, AC voltage and
Ac-side current calculates the power difference between DC side and AC, and the power threshold with setting and resistance according to power difference
Anti- threshold value, it is determined whether send control signal.
Specifically, when power threshold of the power difference more than setting, calculate straight according to power difference and DC voltage
The insulation impedance of side is flowed, also, when impedance threshold of the insulation impedance less than setting, controller 110 determines to send control signal.
When power threshold of the power difference less than setting, or, when power threshold of the power difference more than setting, and insulation impedance is big
When the impedance threshold of setting, controller 110 determines not send control signal.
The protection device of the inversion system of the present embodiment is described in detail below in conjunction with Fig. 1.
By taking the inversion system of photovoltaic generation as an example, reference picture 1, main circuit topology is three-phase bridge circuit to Fig. 1, main circuit
Structure specifically include be sequentially connected DC side breaker S1, DC side Support Capacitor C, inverter DC/AC, three pole reactor L1~
L3, AC relay R and AC breaker S2, and the three-phase filter capacitor C1~C3 in parallel with AC breaker S2.
Additionally, the inverter in Fig. 1 is applied to, but it is not limited to the electrical structure shown in Fig. 1.
The protection device of AD sampling A/D chips, the inversion system is used to control AD by controller 110 in AD sample circuits 120
Sampling A/D chip reads AD data, and AD data include DC voltage Udc, DC side electric current Idc, AC voltage Ua, Ub and Uc,
And ac-side current Ia, Ib and Ic.Compares figure 1, AD sampling A/D chips can gather straight at DC side breaker S1 positions
Stream side voltage Udc, the DC side electric current Idc at DC side Support Capacitor C positions, at three pole reactor L1~L3 positions
Ac-side current Ia, Ib and Ic, and AC voltage Ua, Ub and Uc at AC breaker S2 positions.
The power difference Δ P between DC side and AC is calculated using Udc, Idc, Ua, Ub, Uc, Ia, Ib and Ic, and
Compare the size of Δ P and power threshold Δ P*, Δ P be more than Δ P* when calculate DC side insulation impedance Rx, and compare Rx with
The size of impedance threshold Rx*, the order for disconnecting DC side breaker and AC breaker is sent when Rx is less than Rx*.Switch
Amount control circuit 130 receives the order, and exports the control letter for controlling DC side breaker and AC breaker to disconnect
Number DC side breaker and AC breaker are given, so that controlling DC side breaker and AC breaker to perform disconnects behaviour
Make.
The protection device of the inversion system described further below operation principle in actual applications, it is specific as follows：
Step 1：Inversion system power-up initializing, is input into Rx* and Δ P*.Here, Rx* is can running for default
Minimum insulation resistance value, Δ P* is the threshold value of the power difference between the DC side and AC of setting, can be by host computer
Software is modified and flexible configuration；
Step 2：When inversion system detects DC input voitage in normal range of operation, direct current input current is 0, and three
When cross streams voltage is normal, S1 and S2 is closed, inverter is started working.
Step 3：During grid-connected inverters power output, the protection device of the inversion system reads AD data in real time, calculates straight
Stream side input power and AC power output.
Specifically, DC side input power is calculated by following formula (1), AC power output is calculated by following formula (2)：
Pdc=Udc × Idc ... ... ... ... ... ... ... ... ... ... ... formulas (1)
Wherein, Pdc is DC side input power, and Udc is DC voltage, and Idc is DC side electric current.
P=UaIa+UbIb+UcIc ... ... ... ... ... ... ... ... ... formulas (2)
Wherein, P is AC power output, and Ua is AC A phase voltages, and Ia is AC A phase currents, and Ub is AC
B phase voltages, Ib is AC B phase currents, and Uc is AC C phase voltages, and Ic is AC C phase currents.
Step 4：According to DC side input power and AC power output that step 3 is calculated, counted by following formula (3)
Calculate the power difference Δ P between DC side and AC.
Δ P=P-Pdc ... ... ... ... ... ... ... ... ... ... ... formulas (3)
Wherein, P is AC power output, and Pdc is DC side input power, and Δ P is between DC side and AC
Power difference.
Step 5：The relation of Δ P and Δ P* is judged, if Δ P is less than or equal to Δ P*, then it is assumed that Rx values, can be with more than Rx*
Without calculating Rx values, inversion system normally runs, and return to step 3.If Δ P is more than Δ P*, into step 6.
Step 6：Rx is calculated according to following formula (4).
Rx=Udc2/ΔP
Wherein, Rx is the insulation impedance of DC side, and Udc is DC voltage, and Δ P is the work(between DC side and AC
Rate difference.
Step 7：Judge the relation of Rx and Rx*, if Rx is less than Rx*, disconnect S1 and S2, system-down；If Rx be more than or
During equal to Rx*, inversion system normally runs, and return to step 3, and circulation performs the treatment of above-mentioned steps 3- steps 7.
The protection device of the inversion system of the utility model embodiment, the direct current of inversion system is gathered by AD sample circuits
Side voltage, DC side electric current, AC voltage and ac-side current, controller is according to the data for collecting and the power of setting
Threshold value and impedance threshold, it is determined whether send control signal to digital output modul circuit, further it is determined that sending control signal
Afterwards, digital output modul circuit controls the DC side breaker and AC breaker of inversion system to break according to the control signal
Open, while realizing the insulation impedance that can simply and rapidly obtain DC side, as basis for estimation, so as to occur
Protected for inversion system provides security in time, reliably during failure.
Embodiment two
The structured flowchart that Fig. 2 launches for controller in the protection device of the utility model embodiment two.Can be considered shown in Fig. 1
A kind of specific implementation of device embodiment, shows the concrete structure of controller in Fig. 2, and increased display and alarm
Circuit.
As shown in Fig. 2 controller 110 can include：AD control modules 210, calculating and the judge module 220 being sequentially connected
With digital quantity output control module 230, AD control modules 210 are connected with AD sample circuits 120, digital output control module
230 are connected with digital output modul circuit 130.
Specifically, the AD data that AD sample circuits 120 will be collected are transferred to AD control modules 210, AD control modules 210
The control signal for controlling AD sample circuits 120 to gather AD data is sent, AD data are transferred to calculating and judge module
220, and complete to calculate Δ P, judge Δ P and Δ P* size, calculating Rx, judge Rx and Rx* size treatment, will be final
Judged result is sent to digital output control module 230, and digital output control module 230 is generated according to judged result and is used for
The control signal for controlling the DC side breaker and AC breaker of inversion system to disconnect or close, and it is sent to switch
Amount control circuit 130.
Further, the controller 110 can also include and the fault alarm module for calculating and judge module 220 is connected
240。
Further, the protection device of the inversion system can also include the display being connected with fault alarm module 240
And warning circuit 140, the value for showing insulation impedance, and when insulation impedance is less than impedance threshold, show inverse for characterizing
The warning message that the DC side of change system breaks down.
That is, calculating and judge module 220 judge whether to need alarm by comparing the magnitude relationship of Rx and Rx*.
When needing alarm, calculate and the value and fault data of Rx are sent to fault alarm module 240, fault alarm by judge module 220
The control of module 240 display and the value and warning message of the display of warning circuit 140 Rx.
Preferably, controller 110 can be micro-control unit MCU or field programmable gate array FPGA.
It should be noted that the application is the conventional treatment function of make use of MCU or FPGA, the core of the application is
Controller, AD sample circuits, digital output modul circuit and display and the whole framework of warning circuit composition, and inside controller
Frame structure.
The protection device of the inversion system of the utility model embodiment, on the basis of embodiment illustrated in fig. 1, also with such as
Lower technique effect：
On the one hand, in the present embodiment, controller is by AD control modules, calculating and judge module and digital quantity output control mould
Block, and peripheral circuit (such as AD sample circuits, digital output modul circuit) is joined directly together with modules in controller, it is thus, complete
Into the treatment that data acquisition and calculating judge, so that the insulation impedance of DC side is accurately and quickly obtained, and then in insulation
Impedance be less than impedance threshold when, by digital output control module generate for control inversion system DC side breaker and
The control signal that AC breaker disconnects, drastically increases the safety and reliability of inversion system；
On the other hand, by fault alarm module and connected display and warning circuit, realize exhausted to what is obtained
Edge impedance shown, and when insulation impedance is less than impedance threshold, the display to warning message.Also, the present embodiment knot
Structure is simple, low cost.
Another further aspect, power cell controller is realized by MCU or FPGA, thereby, it is possible to actively be held in the very first time
Row protection act, disconnects AC-DC switch (DC side breaker and AC breaker).So as to further for inversion system is carried
For comprehensive, quick, reliable defencive function.
The above, specific embodiment only of the present utility model, but protection domain of the present utility model do not limit to
In this, any one skilled in the art can readily occur in change in the technical scope that the utility model is disclosed
Or replace, should all cover within protection domain of the present utility model.Therefore, protection domain of the present utility model should be with the power
The protection domain that profit is required is defined.
Claims (8)
1. a kind of protection device of inversion system, it is characterised in that including controller, and be connected with the controller respectively
AD sample circuits and digital output modul circuit：
The AD sample circuits are used to gather DC voltage, DC side electric current, AC voltage and the AC of inversion system
Electric current；
The controller be used for according to collect the DC voltage, the DC side electric current, the AC voltage and
The ac-side current, and setting power threshold and impedance threshold, it is determined whether send control signal；
The digital output modul circuit is used for after the controller determines to send control signal, according to the control for receiving
The DC side breaker and AC breaker of signal control inversion system disconnect.
2. protection device according to claim 1, it is characterised in that the controller is used for described straight according to what is collected
Stream side voltage, the DC side electric current, the AC voltage and the ac-side current are calculated between DC side and AC
Power difference, and according to the power threshold and impedance threshold of the power difference and the setting, it is determined whether send control
Signal.
3. protection device according to claim 2, it is characterised in that the controller is used to be more than when the power difference
During the power threshold of setting, the insulation impedance of DC side is calculated according to the power difference and the DC voltage, also, work as institute
When stating insulation impedance less than the impedance threshold for setting, it is determined that sending control signal.
4. protection device according to claim 3, it is characterised in that the controller is additionally operable to when the power difference is small
When the power threshold of setting, or, when power threshold of the power difference more than setting, and the insulation impedance is more than setting
During fixed impedance threshold, it is determined that not sending control signal.
5. protection device according to claim 3, it is characterised in that the controller includes：The AD controls being sequentially connected
Module, calculating and judge module and digital quantity output control module, the AD control modules are connected with the AD sample circuits,
The digital output control module is connected with the digital output modul circuit.
6. protection device according to claim 5, it is characterised in that the controller also includes and the calculating and judgement
The fault alarm module of module connection.
7. protection device according to claim 6, it is characterised in that aobvious also including what is be connected with the fault alarm module
Show and warning circuit, the value for showing the insulation impedance, and when the insulation impedance is less than impedance threshold, showing is used for
Characterize the warning message that the DC side of the inversion system breaks down.
8. the protection device according to any one of claim 1-7, it is characterised in that the controller is micro-control unit
MCU or field programmable gate array FPGA.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621362560.2U CN206259694U (en) | 2016-12-12 | 2016-12-12 | The protection device of inversion system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621362560.2U CN206259694U (en) | 2016-12-12 | 2016-12-12 | The protection device of inversion system |
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| Publication Number | Publication Date |
|---|---|
| CN206259694U true CN206259694U (en) | 2017-06-16 |
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ID=59029487
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| CN201621362560.2U Active CN206259694U (en) | 2016-12-12 | 2016-12-12 | The protection device of inversion system |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111740392A (en) * | 2020-07-28 | 2020-10-02 | 阳光电源股份有限公司 | Fault protection method, intelligent combiner box and photovoltaic inversion system |
| CN117457436A (en) * | 2023-11-28 | 2024-01-26 | 浙江鲁高电力科技有限公司 | Breaking method, equipment and medium of vacuum circuit breaker for new energy occasion |
-
2016
- 2016-12-12 CN CN201621362560.2U patent/CN206259694U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111740392A (en) * | 2020-07-28 | 2020-10-02 | 阳光电源股份有限公司 | Fault protection method, intelligent combiner box and photovoltaic inversion system |
| CN117457436A (en) * | 2023-11-28 | 2024-01-26 | 浙江鲁高电力科技有限公司 | Breaking method, equipment and medium of vacuum circuit breaker for new energy occasion |
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