CN210430907U - Protection circuit, converter and photovoltaic equipment of contravariant module - Google Patents
Protection circuit, converter and photovoltaic equipment of contravariant module Download PDFInfo
- Publication number
- CN210430907U CN210430907U CN201921472127.8U CN201921472127U CN210430907U CN 210430907 U CN210430907 U CN 210430907U CN 201921472127 U CN201921472127 U CN 201921472127U CN 210430907 U CN210430907 U CN 210430907U
- Authority
- CN
- China
- Prior art keywords
- bridge arm
- circuit
- protection circuit
- module
- groups
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Inverter Devices (AREA)
Abstract
The utility model provides a protection circuit, converter and photovoltaic equipment of contravariant module. The first protection circuit of the inverter module is connected between an upper bridge arm and a lower bridge arm of a single-phase circuit of the inverter module; the first protection circuit is used for switching off an electric connection path between any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm in the three-phase circuit of the inverter module when any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm of the single-phase circuit are simultaneously conducted. Through the utility model discloses, solved and to have carried out the technical problem of current protection to the contravariant module among the correlation technique, avoided the switch tube misconnection to lead to the contravariant module damage, strengthened the stability and the safety of contravariant module.
Description
Technical Field
The utility model relates to a converter field particularly, relates to a protection circuit, converter and photovoltaic equipment of contravariant module.
Background
Traditional power generation technology is mostly thermal power, hydroelectric power, and thermal power needs consume a large amount of primary energy to along with the production of many environmental problems, in order to solve this problem, neotype clean energy has appeared, for example photovoltaic solar energy, wind energy, tidal energy.
The traditional power generation is centralized power generation, and power transmission lines are distributed in each corner of the country and mostly adopt alternating current; new types of energy, such as photovoltaic electricity, belong to the direct current. At present, the use of direct current is still in the starting stage, and alternating current and direct current power grids are interwoven together in life, and alternating current and direct current loads are accompanied. In order to realize the conversion of alternating current and direct current energy, a converter generates an alternating current and direct current conversion module, and the quality of the inversion module directly determines whether the converter can stably operate, but the converter in the related technology has the following problems: the problem of error conduction of upper and lower bridge arms of an Insulated Gate Bipolar Transistor (IGBT); the IGBT is damaged by overcurrent and cannot work normally; the delay problem of the control signal cannot cut off the line in time. And further, the converter and the photovoltaic system cannot operate stably.
In view of the above problems in the related art, no effective solution has been proposed.
SUMMERY OF THE UTILITY MODEL
The utility model provides a protection circuit, converter and photovoltaic equipment of contravariant module to solve at least in the correlation technique and can not carry out the technical problem of current protection to the contravariant module.
In a first aspect, an embodiment of the present invention provides a protection circuit of an inverter module, the circuit includes: the first protection circuit is connected between an upper bridge arm and a lower bridge arm of a single-phase circuit of the inverter module; the first protection circuit is used for switching off an electric connection path between any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm in the three-phase circuit of the inverter module when any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm of the single-phase circuit are simultaneously conducted.
Optionally, the circuit further includes: and the second protection circuit is connected with all the switching tubes of the inverter module through a bus, and is used for switching off all the switching tubes of the inverter module when any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm of the single-phase circuit are simultaneously switched on.
Optionally, the second protection circuit is connected to the first protection circuit, and the second protection circuit is further configured to turn off all switching tubes of the inverter module when any two of the upper bridge arm, the lower bridge arm, and the middle bridge arm of the single-phase circuit are simultaneously turned on and the first protection circuit does not turn off the electrical connection path.
Optionally, the first protection circuit includes two relays and a digital circuit control unit, one of the relays is connected in series between the upper bridge arm and the middle bridge arm, the other relay is connected in series between the lower bridge arm and the middle bridge arm, and the digital circuit control unit is connected in parallel between a drain of the upper bridge arm switching tube and a source of the lower bridge arm switching tube, where the digital circuit control unit is configured to determine whether any two of the upper bridge arm, the lower bridge arm, and the middle bridge arm of the single-phase circuit are simultaneously turned on, and when turned on, trigger a first control signal through a rising edge of the signal, and the two relays are turned off in response to the first control signal.
Optionally, the circuit further includes an internal current sensor for detecting a drain current of the upper bridge arm switching tube, a middle zero potential current of the middle bridge arm, and a source current of the lower bridge arm switching tube, and the digital circuit control unit includes a comparison module and a trigger module, where the comparison module is configured to compare whether any two groups of the drain current, the middle zero potential current, and the source current are the same, and the trigger module is configured to determine that the corresponding two groups of bridge arms are turned on and trigger the first control signal when any two groups of currents are the same.
Optionally, the protection circuit includes three first protection circuits, and the three first protection circuits are respectively connected to each phase circuit of the three-phase circuit of the inverter module.
Optionally, the second protection circuit is a CPU arranged outside the inverter module, and the CPU is configured to determine that two corresponding sets of bridge arms are turned on and send a second control signal for controlling the switching of the switching tubes to all the switching tubes of the inverter module when any two sets of currents of the drain current of the upper bridge arm switching tube, the middle zero potential current of the middle bridge arm, and the source current of the lower bridge arm switching tube are the same.
Optionally, the second control signal is a pulse width modulation PWM wave.
In a second aspect, an embodiment of the present invention provides a converter, which includes the protection circuit of the inverter module of the first aspect.
In a third aspect, an embodiment of the present invention provides a photovoltaic device, which includes the protection circuit of the inverter module of the first aspect.
Through the protection circuit of the inverter module, the current transformer and the photovoltaic equipment provided by the embodiment of the utility model, the protection circuit of the inverter module comprises the first protection circuit, the first protection circuit is connected between the upper bridge arm and the lower bridge arm of the single-phase circuit of the inverter module, when any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm of the single-phase circuit are simultaneously conducted, the electric connection path between any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm in the three-phase circuit of the inverter module is cut off, by controlling the electric connection path between the bridge arms, the over-current and short-circuit protection of the inverter module is realized, therefore, the technical problem that current protection cannot be carried out on the inversion module in the related technology is solved, the inversion module damage caused by misconduction of the switching tube is avoided, and the stability and the safety of the inversion module are enhanced.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without undue limitation to the invention. In the drawings:
fig. 1 is an internal circuit topology diagram of an inverter module according to an embodiment of the present invention;
fig. 2 is a topology diagram of a protection circuit of an inverter module according to an embodiment of the present invention;
fig. 3 is a preferred circuit topology of the protection circuit of the embodiment of the present invention;
fig. 4 is a logic flow diagram for implementing an embodiment of the present invention.
Detailed Description
The features and exemplary embodiments of various aspects of the present invention will be described in detail below, and in order to make the objects, technical solutions, and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention. It will be apparent to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
Fig. 1 is an internal circuit topology diagram of an inverter module according to an embodiment of the present invention, which is also called an IGBT module, and is a circuit configuration of a three-phase three-level 12-arm (three-phase circuit is indicated by a dotted line), three switching tubes (Q1, Q5, and Q9) located on a positive side of a dc bus serving as an upper arm, three switching tubes (Q2, Q6, and Q10) located on a negative side of the dc bus serving as a lower arm, and six switching tubes (Q3 to Q4, Q7 to Q8, and Q11 to Q12) located at a midpoint potential serving as a path for zero-level output, and serving as a middle arm.
In the present embodiment, a protection circuit of an inverter module is provided for protecting the inverter module shown in fig. 1. Fig. 2 is a topology diagram of a protection circuit of an inverter module according to an embodiment of the present invention, and fig. 2 is only illustrated in a left one-phase circuit, and as shown in fig. 2, the protection circuit of the inverter module includes:
the first protection circuit 1 is connected between an upper bridge arm and a lower bridge arm of a single-phase circuit of the inverter module;
the first protection circuit is used for switching off an electric connection path between any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm in the three-phase circuit of the inverter module when any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm of the single-phase circuit are simultaneously conducted (including the simultaneous conduction of the upper bridge arm and the lower bridge arm, the simultaneous conduction of the middle bridge arm and the lower bridge arm and the simultaneous conduction of the middle bridge arm and the lower bridge arm).
In the protection circuit of the inverter module shown in fig. 2, the first protection circuit is connected between an upper bridge arm and a lower bridge arm of a single-phase circuit of the inverter module, and when any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm of the single-phase circuit are simultaneously turned on, the first protection circuit turns off an electric connection path between any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm of a three-phase circuit of the inverter module, and realizes overcurrent and short-circuit protection of the inverter module by controlling the electric connection path between the bridge arms, thereby solving the technical problem that current protection cannot be performed on the inverter module in the related art, avoiding damage of the inverter module caused by misconduction of a switching tube, and enhancing the stability and safety of the inverter module.
In an implementation manner of this embodiment, the protection circuit of the inverter module further includes: and the second protection circuit is connected with all the switching tubes of the inverter module through a bus, and is used for switching off all the switching tubes of the inverter module when any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm of the single-phase circuit are simultaneously switched on. The second protection circuit can be based on the secondary protection of the first protection circuit, namely when the first protection circuit is invalid, the second protection circuit takes effect, and the stability of the inverter module can be protected doubly.
The second protection circuit of this embodiment is connected to the first protection circuit, and the second protection circuit is further configured to turn off all the switching tubes of the inverter module when any two of the upper bridge arm, the lower bridge arm, and the middle bridge arm of the single-phase circuit are simultaneously turned on and the first protection circuit does not turn off the electrical connection path.
The first protection circuit is used for protecting the inverter module for the first time, and the second protection circuit is used for protecting the inverter module for the second time.
In an optional implementation manner of this embodiment, the first protection circuit includes two relays and a digital circuit control unit, one of the relays is connected in series between the upper arm and the middle arm, the other relay is connected in series between the lower arm and the middle arm, and the digital circuit control unit is connected in parallel between a drain of the upper arm switching tube and a source of the lower arm switching tube, where the digital circuit control unit is configured to determine whether any two of the upper arm, the lower arm, and the middle arm of the single-phase circuit are simultaneously turned on, trigger a first control signal through a rising edge of a signal when turned on, and turn off the two relays in response to the first control signal. The problem that a circuit cannot be cut off timely due to delay of an external control signal is solved through a high-speed low-delay digital circuit control unit.
In this embodiment, the circuit further includes an internal current sensor configured to detect a drain current of the upper bridge arm switching tube, a middle zero potential current of the middle bridge arm, and a source current of the lower bridge arm switching tube, and the digital circuit control unit includes a comparison module and a trigger module, where the comparison module is configured to compare whether any two groups of the drain current, the middle zero potential current, and the source current are the same, and the trigger module is configured to determine that the corresponding two groups of bridge arms are turned on and trigger the first control signal when any two groups of currents are the same.
In this embodiment, the protection circuit includes three first protection circuits, which are respectively connected to each phase circuit of the three-phase circuits of the inverter module.
Optionally, the second protection circuit is a CPU arranged outside the inverter module, and the CPU is configured to determine that two corresponding sets of bridge arms are turned on and send a second control signal for controlling the switching of the switching tubes to all the switching tubes of the inverter module when any two sets of currents of the drain current of the upper bridge arm switching tube, the middle zero potential current of the middle bridge arm, and the source current of the lower bridge arm switching tube are the same. Optionally, the second control signal is a Pulse Width Modulation (PWM) wave.
Fig. 3 is a preferred circuit topology diagram of the protection circuit according to the embodiment of the present invention, wherein two relays K are connected in series between the upper bridge arm and the lower bridge arm, a digital circuit control unit is connected in parallel between the drain of the switching tube of the upper bridge arm and the source of the lower bridge arm, corresponding digital circuit control units are also added to the six switching tubes of the midpoint potential, and the output signal of each digital circuit control circuit is subjected to logic operation, so as to output turn-off signals to all relays, thereby performing a short circuit protection at the fastest speed; the CPU collects the current in the analysis circuit, controls the turn-off of the switching tube through the control signal, and cuts off the circuit under the condition that the primary protection fails to form the secondary protection of the inversion unit module.
The whole topological circuit is provided with 12 switching tubes (Q1-Q12), wherein A1-A12 are respectively internal current sensors corresponding to the switching tubes and used for detecting current, six switching tubes of an upper bridge arm and a lower bridge arm are provided with anti-parallel diodes (not shown in the figure) and used as current leakage loops of the switching tubes, and residual charges in the switching tubes are released after the switching tubes are turned off; six switching tubes with midpoint potential are not provided with anti-parallel diodes, two relays (K1-K2, K3-K4 and K5-K6) are connected in series between the upper bridge arm and the lower bridge arm, and control signals of the relays are sent out by a power electronic digital circuit logic unit; the control signal of the switching tube is sent by the CPU.
Fig. 4 is a logic flow chart of the embodiment of the present invention, in which the digital logic operation module acts faster and is used as a protection to cut off the circuit in the fastest time; the CPU control is used as secondary protection, is triggered when the primary protection does not act, ensures the comprehensive protection of the IGBT module, and is used for detecting and controlling each phase and the protection circuit in parallel when the control signal of the turn-off relay (K1-K6) is triggered. Respectively judging whether a1 | | a1 | | a2| | A3, a4 | | A5| | a4 | A6| | A5| | A6, A7 | A8| A7 | | A9| | A8| | A9 are true, if one of them is true, triggering a control signal to disconnect the relays K1 to K6, which is explained in detail below:
the first scheme is as follows: if the upper bridge arm and the lower bridge arm are simultaneously conducted, the drain electrode of the upper bridge arm switching tube and the source electrode of the lower bridge arm switching tube are equal in current (for example, A1 is A3, A4 is A6, and A7 is A9), and the digital circuit logic unit is used for triggering by the rising edge of a signal to control the relay to be turned off, so that the inverter module is protected; and outside the inversion module, the CPU acquires electrical parameters and outputs PWM (pulse-width modulation) waves to control the disconnection of the switching tube, so that the switching tube is used as secondary protection of the IGBT inversion module.
Scheme II: if the upper bridge arm and the middle bridge arm are simultaneously conducted, the currents of the drain electrode of the switching tube of the upper bridge arm and the middle zero potential are equal (for example, A1 is A2, A4 is A5, and A7 is A8), and the currents are triggered by the rising edge of a signal through the current sensor and the digital circuit logic unit to control the relay to be switched off, so that the inverter module is protected; and outside the inversion module, the CPU acquires electrical parameters and outputs PWM (pulse-width modulation) waves to control the disconnection of the switching tube, so that the switching tube is used as secondary protection of the IGBT inversion module.
The third scheme is as follows: if the lower bridge arm and the middle bridge arm are simultaneously conducted, the source of the switch tube of the lower bridge arm is equal to the current at the middle zero potential (for example, A2 is A3, A5 is A6, and A8 is A9), and the current is triggered by the rising edge of a signal through a current sensor and a digital circuit logic unit to control the relay to be turned off, so that the inverter module is protected to serve as primary protection of the IGBT inverter module; and outside the inversion module, the CPU acquires electrical parameters and outputs PWM (pulse-width modulation) waves to control the disconnection of the switching tube, so that the switching tube is used as secondary protection of the IGBT inversion module.
The embodiment also provides a converter, which comprises an inversion module and the protection circuit of the inversion module. The converter carries out stability protection on the inversion module through a protection circuit of the inversion module.
The embodiment also provides a photovoltaic device, and the photovoltaic device comprises an inverter module and the protection circuit of the inverter module. Through the contravariant module of protection converter, the converter can the steady operation, and then has guaranteed the steady operation of the photovoltaic equipment who sets up the converter.
To sum up, through the embodiment of the utility model provides a protection circuit, converter and photovoltaic equipment of contravariant module increases two-stage overcurrent short-circuit protection in the contravariant topology of traditional three-phase three-level 12 bridge arm, utilizes relay and power electronics digital control unit module to constitute primary protection, utilizes CPU's control signal, and the shutoff of control switch pipe is as secondary protection to the security performance and the stability performance of contravariant module have been strengthened greatly. By increasing the safety protection performance of the IGBT module, the phenomenon that the module is burnt due to misconduction of a pipe caused by inaccurate sampling is avoided, and the stability and the safety of the alternating current-direct current conversion system are enhanced.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A protection circuit for an inverter module, comprising:
the first protection circuit is connected between an upper bridge arm and a lower bridge arm of a single-phase circuit of the inverter module;
the first protection circuit is used for switching off an electric connection path between any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm in the three-phase circuit of the inverter module when any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm of the single-phase circuit are simultaneously conducted.
2. The circuit of claim 1, further comprising:
and the second protection circuit is connected with all the switching tubes of the inverter module through a bus, and is used for switching off all the switching tubes of the inverter module when any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm of the single-phase circuit are simultaneously switched on.
3. The circuit of claim 2,
the second protection circuit is connected with the first protection circuit, and is further used for switching off all the switching tubes of the inverter module when any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm of the single-phase circuit are simultaneously switched on and the first protection circuit does not switch off the electric connection path.
4. The circuit of claim 1,
the first protection circuit comprises two relays and a digital circuit control unit, wherein one relay is connected in series between an upper bridge arm and a middle bridge arm, the other relay is connected in series between a lower bridge arm and the middle bridge arm, the digital circuit control unit is connected in parallel between a drain electrode of an upper bridge arm switching tube and a source electrode of a lower bridge arm switching tube, the digital circuit control unit is used for judging whether any two groups of the upper bridge arm, the lower bridge arm and the middle bridge arm of the single-phase circuit are simultaneously conducted or not, a first control signal is triggered through a rising edge of the signal when the upper bridge arm, the lower bridge arm and the middle bridge arm are conducted, and the two relays are turned off in response to the first control.
5. The circuit of claim 4, further comprising:
the digital circuit control unit comprises a comparison module and a trigger module, wherein the comparison module is used for comparing whether any two groups of the drain current, the middle zero potential current and the source current are the same, and the trigger module is used for determining that the corresponding two groups of bridge arms are conducted and triggering the first control signal when any two groups of currents are the same.
6. The circuit of claim 1, wherein the protection circuit comprises three first protection circuits respectively connected to each of the three-phase circuits of the inverter module.
7. The circuit of claim 2,
the second protection circuit is a CPU arranged outside the inversion module, and the CPU is used for determining that two corresponding groups of bridge arms are switched on and sending second control signals for controlling the switching-off of the switching tubes to all the switching tubes of the inversion module when any two groups of currents of the drain current of the upper bridge arm switching tube, the middle zero potential current of the middle bridge arm and the source current of the lower bridge arm switching tube are the same.
8. The circuit of claim 7, wherein the second control signal is a Pulse Width Modulated (PWM) wave.
9. A converter, characterized in that it comprises a protection circuit of an inverter module according to any one of claims 1 to 8.
10. A photovoltaic device characterized in that it comprises a protection circuit of an inverter module according to any one of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921472127.8U CN210430907U (en) | 2019-09-05 | 2019-09-05 | Protection circuit, converter and photovoltaic equipment of contravariant module |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921472127.8U CN210430907U (en) | 2019-09-05 | 2019-09-05 | Protection circuit, converter and photovoltaic equipment of contravariant module |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210430907U true CN210430907U (en) | 2020-04-28 |
Family
ID=70366211
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921472127.8U Active CN210430907U (en) | 2019-09-05 | 2019-09-05 | Protection circuit, converter and photovoltaic equipment of contravariant module |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210430907U (en) |
-
2019
- 2019-09-05 CN CN201921472127.8U patent/CN210430907U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104052026B (en) | For submodule topology and the application thereof of modularization multi-level converter | |
| WO2017024598A1 (en) | Mmc-hvdc system, and direct-current side isolation device and isolation method therefor | |
| CN104067503A (en) | Power converter | |
| JP5730456B1 (en) | Power converter | |
| CN206164112U (en) | A attenuating device is inductiond to anti current potential for photovoltaic power generation system | |
| CN104901410A (en) | UPS circuit | |
| CN112564531A (en) | Switch control method of ANPC type three-level inverter | |
| CN105259500A (en) | Method for detecting fault in relay of three-level grid-connected converter | |
| CN102608468B (en) | Testing system for detecting characteristics of offshore wind power flexible direct current transmission converter | |
| CN106981980A (en) | A kind of full-bridge MMC starts control method and system | |
| TW201338322A (en) | Power generation system and switch device thereof | |
| CN111398772A (en) | Circuit, method and device for converter valve overcurrent turn-off test | |
| CN104796025A (en) | Sub-module topological structure of modular multilevel converter | |
| CN101699699A (en) | Uninterruptible power supply | |
| CN111884244A (en) | Method and system for judging phase of alternating current fault on converter transformer valve side | |
| CN110768233A (en) | Combined high-voltage direct-current circuit breaker applicable to direct-current power grid and having power flow control function and control method thereof | |
| CN110970880B (en) | Converter station containing RL type superconducting current limiter and DC circuit breaker and DC fault processing strategy thereof | |
| CN202563019U (en) | Experimental system for testing characteristics of offshore wind electric flexible direct current transmission converter | |
| CN105186550A (en) | Improved modularized multi-level converter submodule topology | |
| CN210430907U (en) | Protection circuit, converter and photovoltaic equipment of contravariant module | |
| JPWO2016170672A1 (en) | Power converter | |
| CN103762588A (en) | Micro-grid operating inverter grid-connection and off-grid smooth switching circuit and control method thereof | |
| CN204205576U (en) | A kind of T link differential protection | |
| CN214750546U (en) | Direct-current ground insulation impedance detection circuit for bridge arm topology converter | |
| CN212649375U (en) | Silicon carbide driving device and driving system thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |