CN209982093U - Unbalanced fault ride-through control device of photovoltaic inverter - Google Patents
Unbalanced fault ride-through control device of photovoltaic inverter Download PDFInfo
- Publication number
- CN209982093U CN209982093U CN201921363202.7U CN201921363202U CN209982093U CN 209982093 U CN209982093 U CN 209982093U CN 201921363202 U CN201921363202 U CN 201921363202U CN 209982093 U CN209982093 U CN 209982093U
- Authority
- CN
- China
- Prior art keywords
- power
- current
- signal
- unit
- photovoltaic inverter
- 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
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/50—Arrangements for eliminating or reducing asymmetry in polyphase networks
Landscapes
- Inverter Devices (AREA)
Abstract
The utility model discloses an unbalanced fault ride-through control device of a photovoltaic inverter, which comprises a signal acquisition unit, a direct current voltage control unit, a power support calculation unit, a power-current conversion unit and a current control unit which are connected in sequence from the signal input to the output direction; the direct-current voltage control unit is used for obtaining an output active power reference value meeting maximum power tracking; the power support calculation unit is used for correcting the output active power reference value when the phase voltage exceeds a fault voltage threshold value so as to obtain active power and reactive power which are required to be provided by the photovoltaic inverter for fault ride-through; the power-current conversion unit is used for converting the power value calculated by the power support calculation unit into a corresponding current reference value; the current control module is used for generating modulation pulses for controlling the on-off of the photovoltaic inverter. The utility model provides an among the prior art can not control the photovoltaic power supply when the electric wire netting trouble and carry out the technical problem that the trouble crossed.
Description
Technical Field
The utility model relates to a photovoltaic power control field.
Background
Distributed power sources connected to medium and low voltage distribution networks play a core role in future power distribution systems. With a suitably integrated configuration, distributed power supplies present two advantages: the power transmission efficiency of the system is improved by avoiding long-distance power transmission; most distributed power supplies are based on renewable energy sources such as wind energy, solar energy and the like, and the emission amount is reduced. Therefore, their integration with power distribution systems is one of the major challenges the power industry will face in the coming years. Up to now, the access standards for distributed power are mostly defensive, with emphasis on safe operation. For example, IEEE-1547 specifies that in the event of a fault anomaly, the distributed power supply should be disconnected from the grid as quickly as possible. As the amount of distributed power access increases, grid operating rules are also gradually modified to provide ancillary services to the power system, such as: active power output control, steady state voltage management and fault ride through capability. The latter requires not only that the distributed power supply remain connected in the event of a fault, but also that it support the grid by injecting reactive power. With the continuous decline of production cost of photovoltaic panels, solar power generation is more competitive than other forms of renewable energy sources and is therefore deployed on a large scale. Most of existing photovoltaic power supply control devices adopt a current control method, and the problem of electric energy quality of a certain aspect is optimized by injecting reference current. The reference current is usually unbalanced distortion current, and the prior method usually adopts a plurality of PI controllers based on d-q rotation coordinate transformation to track each sequence and each subharmonic injection current. The method needs to extract current feedback quantity in a direct current mode through rotation conversion, so that the dynamic characteristic of a photovoltaic system is limited when fault ride-through occurs, and sufficient reactive support cannot be provided for a power grid, so that off-grid operation is caused.
SUMMERY OF THE UTILITY MODEL
Not enough to above-mentioned prior art, the utility model provides a photovoltaic inverter's unbalanced fault passes through controlling means solves and can not control the photovoltaic power supply when the electric wire netting trouble among the prior art and carries out the technical problem that the trouble passed through.
In order to solve the technical problem, the utility model discloses a following technical scheme: an unbalanced fault ride-through control device of a photovoltaic inverter is characterized in that: the device comprises a signal acquisition unit, a direct-current voltage control unit, a power support calculation unit, a power-current conversion unit and a current control unit which are sequentially connected from the signal input direction to the signal output direction;
the signal acquisition unit comprises a signal input unit, a signal conditioning module and an A/D analog-to-digital conversion module; the signal input unit is used for monitoring three-phase voltage and three-phase current sequence of the power distribution network in real time; the signal conditioning module is used for converting the bipolar signal monitored by the signal input unit into a unidirectional sinusoidal signal and outputting the unidirectional sinusoidal signal to the A/D analog-to-digital conversion module; the A/D analog-to-digital conversion module is used for converting the unidirectional sinusoidal signal into a digital signal and outputting the digital signal to the direct-current voltage control unit;
the direct current voltage control unit is used for outputting a voltage reference value which is calculated according to a maximum power point tracking algorithm and meets maximum power tracking and a real-time voltage value which is acquired through the signal acquisition unit to the PI controller so as to obtain an output active power reference value which meets maximum power tracking;
the power support calculation unit is used for correcting the output active power reference value by combining the real-time phase voltage monitored by the signal acquisition unit when the phase voltage exceeds a fault voltage threshold value so as to obtain active power and reactive power required by the photovoltaic inverter to perform fault ride-through;
the power-current conversion unit is used for converting the power value calculated by the power support calculation unit into a corresponding current reference value;
the current control module is used for generating a modulation pulse for controlling the on-off of the photovoltaic inverter according to the deviation between the current reference value and the real-time phase current monitored by the signal acquisition unit.
Compared with the prior art, the utility model discloses following beneficial effect has:
1. the utility model discloses gather voltage and current signal simultaneously, form and support calculation module, power-current conversion unit to current control unit's signal flow from direct current voltage control unit, power in proper order, voltage control unit, power support calculation module, power-current conversion unit to current control unit's hardware connection relation is the basis that forms this signal flow.
2. And each unit processes corresponding signals in the signal flow, and the loops are buckled with each other to finally obtain the modulation pulse capable of meeting the fault ride-through control. Wherein, the correction of the output power reference value by the power support calculation unit is the key for realizing the fault ride-through control. In addition, it is to be stated that: the signal processing method or procedure of each unit is prior art, and does not relate to the improvement to signal processing method, the technical scheme of the utility model is that the technical problem that the prior art can not carry out fault ride-through control is solved through establishing above-mentioned signal flow direction on the whole.
3. The utility model discloses gather three-phase voltage, current signal simultaneously to can provide the trouble respectively to the three-phase of distribution network and pass through control, make each looks homoenergetic tend to the same control target, pass through control with the trouble that realizes symmetrical trouble and asymmetric trouble.
Drawings
Fig. 1 is a circuit block diagram of an unbalanced fault ride-through control apparatus of a photovoltaic inverter;
fig. 2 is a circuit block diagram of a signal acquisition unit.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and preferred embodiments.
Referring to fig. 1, an unbalanced fault ride-through control apparatus for a photovoltaic inverter includes a signal acquisition unit, a dc voltage control unit, a power support calculation unit, a power-current conversion unit, and a current control unit, which are sequentially connected from a signal input direction to an output direction;
referring to fig. 2, the signal acquisition unit includes a signal input unit, a signal conditioning module, and an a/D analog-to-digital conversion module; the signal input unit is used for monitoring three-phase voltage and three-phase current sequence of the power distribution network in real time; the signal conditioning module is used for converting the bipolar signal monitored by the signal input unit into a unidirectional sinusoidal signal and outputting the unidirectional sinusoidal signal to the A/D analog-to-digital conversion module; the A/D analog-to-digital conversion module is used for converting the unidirectional sinusoidal signal into a digital signal and outputting the digital signal to the direct-current voltage control unit;
the direct current voltage control unit is used for outputting a voltage reference value which is calculated according to a maximum power point tracking algorithm and meets maximum power tracking and a real-time voltage value which is acquired through the signal acquisition unit to the PI controller so as to obtain an output active power reference value which meets maximum power tracking;
the power support calculation unit is used for correcting the output active power reference value by combining the real-time phase voltage monitored by the signal acquisition unit when the phase voltage exceeds a fault voltage threshold value so as to obtain active power and reactive power required by the photovoltaic inverter to perform fault ride-through;
the power-current conversion unit is used for converting the power value calculated by the power support calculation unit into a corresponding current reference value;
the current control module is used for generating a modulation pulse for controlling the on-off of the photovoltaic inverter according to the deviation between the current reference value and the real-time phase current monitored by the signal acquisition unit.
The power support calculation unit presets a voltage threshold range, when the voltage threshold range is not detected to exceed the fault voltage threshold, the fault ride-through control is not required to be provided at the moment, the active power reference value of the direct current voltage control unit is not corrected, and the output power reference value is directly sent to the power-current conversion unit.
In this embodiment, the signal input unit includes 4 voltage transformers for respectively monitoring three-phase voltage and zero-sequence voltage and 4 current transformers for respectively monitoring three-phase current and zero-sequence current.
In this embodiment, the signal conditioning module is an NSA2300 chip. The A/D analog-to-digital conversion module is a MAX1320 chip. The direct-current voltage control unit adopts an SST89E/V554RC chip with a built-in PI controller. The power support computing unit employs an ADE7754 chip. The power-current conversion unit adopts an HLW8012 chip. The current control unit adopts an ARM processor with the model number of LPC 2136.
The utility model provides a photovoltaic inverter's trouble passes through required reactive support that provides of photovoltaic when controlling means priority has considered outside electric wire netting trouble, guarantees the trouble and passes through the ability. When an external fault occurs, the photovoltaic system needs to provide reactive support for the system in addition to active power in order to realize fault ride-through. And the power support calculation unit corrects the active power reference value given by the direct current voltage control unit according to the voltage drop condition obtained by the signal acquisition unit to obtain active and reactive supports which are required to be provided for the system by the photovoltaic system to keep the non-off-line operation. And finally, generating a modulation pulse for controlling the on-off of the photovoltaic inverter by a current control unit according to the deviation of the reference current and the actual grid-connected point current, thereby realizing the photovoltaic fault ride-through control.
Claims (8)
1. An unbalanced fault ride-through control device of a photovoltaic inverter is characterized in that: the device comprises a signal acquisition unit, a direct-current voltage control unit, a power support calculation unit, a power-current conversion unit and a current control unit which are sequentially connected from the signal input direction to the signal output direction;
the signal acquisition unit comprises a signal input unit, a signal conditioning module and an A/D analog-to-digital conversion module; the signal input unit is used for monitoring three-phase voltage and three-phase current sequence of the power distribution network in real time; the signal conditioning module is used for converting the bipolar signal monitored by the signal input unit into a unidirectional sinusoidal signal and outputting the unidirectional sinusoidal signal to the A/D analog-to-digital conversion module; the A/D analog-to-digital conversion module is used for converting the unidirectional sinusoidal signal into a digital signal and outputting the digital signal to the direct-current voltage control unit;
the direct current voltage control unit is used for outputting a voltage reference value which is calculated according to a maximum power point tracking algorithm and meets maximum power tracking and a real-time voltage value which is acquired through the signal acquisition unit to the PI controller so as to obtain an output active power reference value which meets maximum power tracking;
the power support calculation unit is used for correcting the output active power reference value by combining the real-time phase voltage monitored by the signal acquisition unit when the phase voltage exceeds a fault voltage threshold value so as to obtain active power and reactive power required by the photovoltaic inverter to perform fault ride-through;
the power-current conversion unit is used for converting the power value calculated by the power support calculation unit into a corresponding current reference value;
the current control module is used for generating a modulation pulse for controlling the on-off of the photovoltaic inverter according to the deviation between the current reference value and the real-time phase current monitored by the signal acquisition unit.
2. The apparatus for controlling unbalanced fault ride-through of a photovoltaic inverter according to claim 1, wherein: the signal input unit comprises 3 voltage transformers for respectively monitoring three-phase voltage and 3 current transformers for respectively monitoring three-phase current.
3. The apparatus for controlling unbalanced fault ride-through of a photovoltaic inverter according to claim 1, wherein: the signal conditioning module is an NSA2300 chip.
4. The apparatus for controlling unbalanced fault ride-through of a photovoltaic inverter according to claim 1, wherein: the A/D analog-to-digital conversion module is a MAX1320 chip.
5. The apparatus for controlling unbalanced fault ride-through of a photovoltaic inverter according to claim 1, wherein: the direct-current voltage control unit adopts an SST89E/V554RC chip with a built-in PI controller.
6. The apparatus for controlling unbalanced fault ride-through of a photovoltaic inverter according to claim 1, wherein: the power support computing unit employs an ADE7754 chip.
7. The apparatus for controlling unbalanced fault ride-through of a photovoltaic inverter according to claim 1, wherein: the power-current conversion unit adopts an HLW8012 chip.
8. The apparatus for controlling unbalanced fault ride-through of a photovoltaic inverter according to claim 1, wherein: the current control unit adopts an ARM processor with the model number of LPC 2136.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921363202.7U CN209982093U (en) | 2019-08-21 | 2019-08-21 | Unbalanced fault ride-through control device of photovoltaic inverter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921363202.7U CN209982093U (en) | 2019-08-21 | 2019-08-21 | Unbalanced fault ride-through control device of photovoltaic inverter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209982093U true CN209982093U (en) | 2020-01-21 |
Family
ID=69251726
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921363202.7U Active CN209982093U (en) | 2019-08-21 | 2019-08-21 | Unbalanced fault ride-through control device of photovoltaic inverter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209982093U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111600336A (en) * | 2020-05-27 | 2020-08-28 | 国网山西省电力公司电力科学研究院 | Photovoltaic inverter control method considering voltage support during unbalanced voltage sag |
-
2019
- 2019-08-21 CN CN201921363202.7U patent/CN209982093U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111600336A (en) * | 2020-05-27 | 2020-08-28 | 国网山西省电力公司电力科学研究院 | Photovoltaic inverter control method considering voltage support during unbalanced voltage sag |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107181274B (en) | Method for accessing new energy into flexible direct current power grid | |
| CN108599200B (en) | Emergency power limit control method for island new energy accessed through true bipolar flexible direct current power grid | |
| CN108718094B (en) | Method for improving low voltage ride through performance of large photovoltaic system | |
| US20180166883A1 (en) | Low voltage ride-through control system and method for multi-inverter grid-connected power converter | |
| CN106786737B (en) | A kind of low voltage traversing control method for collecting and distributing type photovoltaic generating system | |
| CN109347144B (en) | Low voltage ride through method of wind power flexible direct current output system | |
| CN104734191A (en) | Photovoltaic grid-connected inverter low-voltage ride through method based on reactive current injection | |
| CN111509754B (en) | Fault ride-through control method for offshore wind power direct current collecting and conveying system | |
| CN107069809A (en) | A kind of directly driven wind-powered current transformer high voltage crossing control method | |
| CN104124701B (en) | A kind of photovoltaic combining inverter DC component inhibition method | |
| CN110247419B (en) | Control method suitable for multi-end back-to-back flexible straightening | |
| CN107196327B (en) | Feedforward control method for restraining power oscillation of modular voltage source type converter valve | |
| CN112217192B (en) | Direct-current coupling photovoltaic off-grid hydrogen production system and control method thereof | |
| CN109256781B (en) | Method and device for adjusting reactive power of photovoltaic inverter in photovoltaic power station | |
| Quraan et al. | A new control scheme of back-to-back converter for wind energy technology | |
| CN209982093U (en) | Unbalanced fault ride-through control device of photovoltaic inverter | |
| KR101705467B1 (en) | Direct Power Control for Wind Turbine | |
| CN112086988B (en) | Smooth switching method for control strategy of voltage source type converter | |
| CN109066817A (en) | A kind of light storage micro-grid system and reactive power support control method based on Active Disturbance Rejection Control | |
| Phap et al. | Design of novel grid-tied solar—Wind hybrid power plant using photovoltaic cell emulating system | |
| CN103872932A (en) | Grid-side PWM (pulse width modulation) rectifier | |
| CN107994603B (en) | Fault ride-through control method and system based on virtual synchronous generator | |
| Chindamanee et al. | Dual-mode operation of pv power converters for flexible power tracking | |
| Allagui et al. | Grid support capabilities of direct drive wind turbines during faults for uninterrupted operation mode | |
| Raza et al. | Control design strategy to enhance the fault-ride-through capability of vsc-hvdc transmission system interconnecting offshore wind power plant |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |