CN111525583B - Voltage regulating transformer and power flow control system - Google Patents
Voltage regulating transformer and power flow control systemInfo
- Publication number
- CN111525583B CN111525583B CN202010550443.3A CN202010550443A CN111525583B CN 111525583 B CN111525583 B CN 111525583B CN 202010550443 A CN202010550443 A CN 202010550443A CN 111525583 B CN111525583 B CN 111525583B
- Authority
- CN
- China
- Prior art keywords
- transformer
- voltage
- phase
- voltage regulating
- converter
- 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
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
- H02J3/12—Arrangements for adjusting voltage in AC networks by changing a characteristic of the network load
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
- H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
- H02J3/1821—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators
-
- 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
- Y02E40/30—Reactive power compensation
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Supply And Distribution Of Alternating Current (AREA)
- Inverter Devices (AREA)
Abstract
本发明公开了一种调压变压器及潮流控制系统，调压变压器包括：变压器及至少一个调压电路，其中，变压器一次侧绕组与交流系统连接，其二次侧绕组的一端与至少一个调压电路串联连接，二次侧绕组另一端与交流系统连接；调压电路包括至少一个开关模块，通过控制开关模块的通断状态，控制调压电路输出电压。本发明将变压器二次侧绕组与至少一个调压电路连接，通过改变开关模块通断状态，调整调压电路输出端电压，并且通过改变调压绕组全部接入变压器时输出端电压幅值，从而实现多档调压，以及对交流系统输电线路电压幅值的控制。
The present invention discloses a voltage-regulating transformer and power flow control system. The voltage-regulating transformer comprises a transformer and at least one voltage-regulating circuit. The transformer's primary winding is connected to an AC system, one end of its secondary winding is connected in series with the at least one voltage-regulating circuit, and the other end of the secondary winding is connected to the AC system. The voltage-regulating circuit comprises at least one switch module, and the output voltage of the voltage-regulating circuit is controlled by controlling the on-off state of the switch module. The present invention connects the transformer's secondary winding to the at least one voltage-regulating circuit, adjusts the voltage at the output of the voltage-regulating circuit by changing the on-off state of the switch module, and changes the output voltage amplitude when all the voltage-regulating windings are connected to the transformer, thereby achieving multi-level voltage regulation and controlling the voltage amplitude of the AC system's transmission line.
Description
Technical Field
The invention relates to the technology of power equipment, in particular to a voltage regulating transformer and a power flow control system.
Background
With the rapid development of economy, the continuous increase of social electricity consumption and increasingly complex and flexible power grid structures bring higher requirements for safe and economic operation of a power system. In order to ensure safe and economical operation of the power grid, the power flow control system is indispensable for flexible control of power flow. A Flexible Alternating Current Transmission System (FACTS) utilizes a power electronic device to adjust the operation parameters of a power grid, so that the line power flow is effectively regulated. The unified power flow controller (Unified Power Flow Controller, UPFC) is the most powerful device in FACTS, can adjust line terminal voltage and line parameters, has fast and independent power flow regulation and control capability, and has good performance in the aspects of dynamic reactive power compensation, power grid stability maintenance and the like. However, UPFC is mainly composed of high-voltage high-power electronic devices, which are expensive, and the switching loss is much higher than that of the traditional electric devices such as transformers, and the reliability is inferior to that of the traditional devices. In view of economic factors and the like, the UPFC is not widely applied to high-voltage power networks. The traditional transformer tapping switch is slow in action speed, has arcing risk, and influences the service life of the transformer tapping switch through multiple actions. Meanwhile, the system has no capability on the conditions of system oscillation and the like, and the dynamic flexible support target of the power grid voltage cannot be realized.
Disclosure of Invention
Therefore, the technical problem to be solved by the invention is to overcome the defect that the transformer in the prior art cannot realize dynamic flexible support on the power grid voltage, so as to provide a voltage regulating transformer and a power flow control system.
In order to achieve the above purpose, the present invention provides the following technical solutions:
In a first aspect, an embodiment of the invention provides a voltage regulating transformer, which comprises a transformer and at least one voltage regulating circuit, wherein a primary side winding of the transformer is connected with an alternating current system, one end of a secondary side winding of the transformer is connected with the at least one voltage regulating circuit in series, the other end of the secondary side winding is connected with the alternating current system, the voltage regulating circuit comprises at least one switch module, and the output voltage of the voltage regulating circuit is controlled by controlling the on-off state of the switch module.
In an embodiment, the voltage regulating circuit comprises a voltage regulating winding, two output ends and four switch modules, wherein one ends of a first switch module and a third switch module are connected with one end of the voltage regulating winding, the other end of the first switch module is connected with one end of a second switch module, the first output end is led out at the first connection point, the other end of the third switch module is connected with one end of a fourth switch module, the second output end is led out at the second connection point, and the other ends of the second switch module and the fourth switch module are both connected with the other end of the voltage regulating winding.
In one embodiment, when the secondary winding of the transformer is connected to a plurality of voltage regulating circuits, the outputs of all the voltage regulating circuits are interconnected in series.
In one embodiment, the transformer is a single-phase transformer or a three-phase transformer.
In an embodiment, when the voltage regulating transformer includes a transformer and a voltage regulating circuit, the voltage regulating circuit is connected in series with a secondary winding of the transformer, and by controlling the on-off state of the switch module, the output voltages of two output ends of the voltage regulating circuit are three-level voltages.
In an embodiment, when the voltage regulating transformer includes a transformer and two voltage regulating circuits, the two voltage regulating circuits are connected in series and then connected in series with a secondary winding of the transformer, and by controlling the on-off state of the switch module, the output voltages of the two output ends after the two voltage regulating circuits are connected in series are nine-level voltages.
In an embodiment, when the voltage regulating transformer includes a transformer and three voltage regulating circuits, the three voltage regulating circuits are connected in series and then connected in series with a secondary winding of the transformer, and by controlling the on-off state of the switch module, the output voltages of the two output ends after the three voltage regulating circuits are connected in series are twenty-seven levels of voltage.
In a second aspect, the embodiment of the invention provides a power flow control system, which comprises a voltage regulating transformer in the first aspect, a controller and at least one converter, wherein the input side of the converter is connected with a primary side winding of the voltage regulating transformer, the output side of the converter is connected with the output end of a voltage regulating circuit on a secondary side of the voltage regulating transformer, the converter is used for regulating the voltage amplitude and the phase of an alternating current system, and the controller is arranged on a power line of the alternating current system and used for collecting the voltage and the current of a mounting point, a node and a branch in a preset adjacent range or receiving an upper-level dispatching instruction and changing the voltage and the power flow of the alternating current system by coordinating the voltage regulating circuit and the output voltage amplitude and the phase of the converter.
In one embodiment, the power flow control system further comprises at least one bypass switch module, wherein the voltage regulating circuit and the current converter are connected in parallel with one bypass switch, the bypass switch module is used for rapidly cutting off fault points when any one of the voltage regulating circuit or the current converter breaks down, or the output end of the voltage regulating circuit is connected with the current converter through the bypass switch module, and the bypass switch module is used for cutting off current loops of the voltage regulating circuit and the current converter when the voltage regulating circuit or the current converter breaks down.
In an embodiment, when the voltage regulating transformer is a single-phase transformer, one end of a primary winding of the single-phase transformer is connected with any one phase transmission line of the ac system, the other end of the primary winding of the single-phase transformer and the self-coupling output end are connected with the input side of the converter, and one end of the output side of the converter is connected with the output end of the voltage regulating circuit of the secondary side of the single-phase transformer.
In an embodiment, when the voltage regulating transformer is a three-phase transformer and the converter is a single-phase converter, the autotransformer output end of the primary winding of each phase of the three-phase transformer is connected with one end of the input side of one converter, the other ends of the input sides of the three converters are connected with each other, and one end of the output side of each converter is connected with the output end of the voltage regulating circuit of the corresponding secondary side of the three-phase transformer.
In one embodiment, the power flow control system further comprises at least one additional transformer, when the voltage regulating transformer is a three-phase transformer and the converter is a three-phase converter, the autotransformer output end of each phase primary side winding of the three-phase transformer is correspondingly connected with each converter input side, each phase of the converter output side is connected with one end of each phase primary side winding of the additional transformer, the other end of each phase primary side winding of the additional transformer is connected with each other, one end of each secondary side winding of the additional transformer is respectively connected with the low potential output end or the high potential output end of the voltage regulating circuit of the corresponding phase secondary side of the three-phase transformer, and the other ends of the secondary side windings of the three additional transformers are connected with each other.
In an embodiment, when one end of each secondary winding of the additional transformer is connected to the high-potential output end of the voltage regulating circuit of the corresponding phase secondary side of the three-phase transformer, one end of each secondary winding of the three-phase transformer is connected to ground, the other end of each secondary winding of the three-phase transformer is connected to the corresponding secondary winding of the additional transformer, and the low-potential output end of the voltage regulating circuit of the corresponding phase secondary side of the three-phase transformer is connected to the corresponding ac system power transmission line.
In an embodiment, when one end of each secondary winding of the additional transformer is connected to the low-potential output end of the voltage regulating circuit of the corresponding phase secondary side of the three-phase transformer, one end of each secondary winding of the three-phase transformer is connected to the corresponding ac system power transmission line, the other end of each secondary winding of the three-phase transformer is connected to the voltage regulating circuit, and the high-potential output end of the voltage regulating circuit of the corresponding phase secondary side of the three-phase transformer is connected to the corresponding ac system power transmission line.
The technical scheme of the invention has the following advantages:
1. The voltage regulating transformer provided by the invention has the advantages that the secondary side winding of the transformer is connected with at least one voltage regulating circuit, the voltage of the output end of the voltage regulating circuit is regulated by changing the on-off state of the switch module, and the voltage amplitude of the output end is regulated by changing the voltage amplitude of the voltage regulating winding when all the voltage regulating windings are connected into the transformer, so that the multi-gear voltage regulation and the control of the voltage amplitude of the transmission line of an alternating current system are realized.
2. The power flow control system provided by the invention introduces the energy taking of the parallel connection of the converter and the primary side of the transformer on the basis of the voltage regulating transformer, the output end of the converter is connected with the secondary side of the transformer in series, the parallel reactive compensation of the alternating current system and the control of the voltage amplitude and the phase of the transmission line of the alternating current system are realized by controlling the running state of the converter, the power flow control capability of the alternating current system is enhanced, when the voltage regulating transformer is a three-phase transformer, the converter can be a single-phase transformer or a three-phase transformer, when the voltage regulating transformer is a single-phase transformer, the converter can be a single-phase transformer, so that the flexibility adaptability of the power flow control system is improved, and the running state of the converter is controlled by the controller, so that the stability of the power flow control system and the power flow control capability are improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic diagram of a specific example of a voltage regulating transformer according to an embodiment of the present invention;
Fig. 2 is a schematic diagram of a specific example of a voltage regulating circuit according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a specific example of a bypass switch module according to an embodiment of the present invention;
fig. 4 is a schematic diagram of a specific example of a power flow control system according to an embodiment of the present invention;
Fig. 5 is a voltage regulation range of the voltage regulating transformer and the converter for matching voltage regulation according to the embodiment of the present invention;
fig. 6 is a schematic diagram of another specific example of a voltage regulating circuit according to an embodiment of the present invention;
Fig. 7 is a schematic diagram of another specific example of a power flow control system according to an embodiment of the present invention;
Fig. 8 is a schematic diagram of another specific example of a power flow control system according to an embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the description of the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected via an intermediate medium, and in communication with each other between two elements, and wirelessly connected, or wired. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
In addition, the technical features of the different embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.
Example 1
The embodiment of the invention provides a voltage regulating transformer 1, which is applied to occasions needing to regulate the voltage of a power transmission line, as shown in fig. 1, and comprises a transformer 11 and at least one voltage regulating circuit 12.
In the embodiment of the invention, a primary side winding of the transformer is connected with an alternating current system, one end of a secondary side winding of the transformer is connected with at least one voltage regulating circuit in series, and the other end of the secondary side winding is connected with the alternating current system. The voltage regulating circuit comprises at least one switch module, the output voltage of the voltage regulating circuit is controlled by controlling the on-off state of the switch module, the primary side of the transformer can be a primary side or a secondary side, and the secondary side is the opposite side of the primary side.
The transformer in fig. 1 is a single-phase transformer, the primary side of which is connected to a phase transmission line of an ac system, one end of a secondary winding (one end of a normal winding) of which is connected to at least one series-connected voltage regulating circuit (fig. 2 illustrates that one end of the secondary winding is connected to two series-connected voltage regulating circuits), and the other end of the normal winding is connected to a corresponding phase transmission line of the ac system.
When the transformer is a three-phase transformer, the primary side of the three-phase transformer is connected with an alternating current system, one end of each phase winding (one end of a conventional winding) of the secondary side of the three-phase transformer is connected with at least one voltage regulating circuit, and the other end of each phase conventional winding of the secondary side of the three-phase transformer is connected with a power transmission line corresponding to the alternating current system.
As shown in fig. 2, the voltage regulating circuit includes a voltage regulating winding 121, two output terminals, and four switch modules 122. One end of the first switch module S1 and one end of the third switch module S3 are connected with one end of the voltage regulating winding, the other end of the first switch module S1 and one end of the second switch module S2 are connected to a first connecting point, a first output end is led out at the first connecting point, the other end of the third switch module S3 and one end of the fourth switch module S4 are connected to a second connecting point, a second output end is led out at the second connecting point, and the other end of the second switch module S2 and the other end of the fourth switch module S4 are connected with the other end of the voltage regulating winding.
Fig. 2 shows a voltage regulating circuit comprising a voltage regulating winding and four controllable switch modules, wherein the voltage regulating circuit comprises two output ends, and a plurality of voltage regulating circuits are connected in series through the output ends. In fig. 2, four controllable switch modules S1, S2, S3, S4 form an H-bridge structure, each controllable switch module may be formed by an anti-parallel thyristor, or a bi-directional conducting IGBT and an anti-parallel diode connected in series to each other, and the switch module in fig. 2 is formed by a bi-directional conducting IGBT and an anti-parallel diode thereof, which is not limited thereto.
It should be noted that, the number of voltage regulating circuits and the number of turns of the voltage regulating windings connected in series can be set according to practical situations, and when the secondary side conventional winding of the transformer is connected with a plurality of voltage regulating circuits, the number of turns of each voltage regulating winding can be different.
In fig. 2, one ends of S1 and S3 are connected to a first end of the voltage-regulating winding, the other end of S1 is connected to one end of S2, and then connected together to and led out of the first output end, the other end of S3 is connected to one end of S4, and then connected together to and led out of the second output end, and the other ends of S2 and S4 are both connected to a second end of the voltage-regulating winding.
It should be noted that, in the embodiment of the present invention, the number of the switch modules may be not only 4, but also other numbers, and the plurality of switch modules may not only form an H-bridge structure, and meanwhile, according to the practical situation of the application site of the voltage regulating transformer, the plurality of switch modules may form a plurality of H-bridge structures, or the switch modules are connected with the first end, the second end and the self-coupling output end of the voltage regulating winding, and by changing the on-off state of the switch modules, all forward access, or reverse access, or incomplete forward access and incomplete reverse access of the voltage regulating winding may be enabled to be connected with the secondary side winding of the transformer, so as to change the total voltage output after the secondary side of the transformer is connected with the voltage regulating circuit in series.
In a specific embodiment, the voltage regulating transformer further comprises at least one bypass switch module, the voltage regulating circuits are all connected in parallel with one bypass switch, the bypass switch module is used for rapidly cutting off all the voltage regulating circuits when any one voltage regulating circuit is arranged, as shown in fig. 3, two ends of the bypass switch module are respectively connected with two output ends of the voltage regulating circuits after the two ends of the bypass switch module are connected in series, and one end of the bypass switch module is grounded. The bypass switch module in fig. 3 is a controllable thyristor switch for rapid bypass fault point, and may further comprise a mechanical switch for reliable bypass fault point, and a lightning arrester for end-to-end overvoltage protection. When the voltage regulating circuit is positioned at the low potential end of the transformer, one end of the bypass switch module can be directly grounded, so that the bypass switch module is conducted to the transformer to have a stable and reliable grounding point.
In the embodiment of the invention, the output voltage amplitude of the two output ends of the voltage regulating winding after being fully connected to the secondary side of the transformer can be changed by changing the number of turns of the voltage regulating winding.
In the embodiment of the invention, when the voltage regulating transformer comprises a transformer and a voltage regulating circuit, the voltage regulating circuit is connected in series with a secondary side winding of the transformer, and the output voltages of two output ends of the voltage regulating circuit are three-level voltages by controlling the on-off state of the switch module.
The embodiment of the invention can realize three states of forward winding voltage, reverse winding voltage and zero voltage output by the module by controlling the on-off state of the switch module in the H-bridge structure. As shown in fig. 2, when the primary side current and the secondary side current of the transformer flow into the windings from the same-name terminals, assuming that the voltage between the first output terminal and the second output terminal is U1 when the voltage regulating winding is connected to the transformer in the forward direction, the voltage between the first output terminal and the second output terminal is-U1 when the voltage regulating winding is connected to the transformer in the reverse direction, the voltage between the two ends of the conventional winding of the transformer is U, and the voltage regulating circuit is controlled as follows:
① By controlling the on state of the S1 and the S4 and the off state of the S2 and the S3, the forward voltage of the voltage regulating winding is output between the first output end and the second output end of the voltage regulating circuit, and the voltage output after the conventional winding of the transformer is connected with the voltage regulating circuit in series is U+U1;
② By controlling the on state of the S2 and the S3 and the off state of the S1 and the S4, negative voltage of the voltage regulating winding is output between the first output end and the second output end of the voltage regulating circuit, and the voltage output after the conventional winding of the transformer is connected with the voltage regulating circuit in series is U-U1;
③ And controlling the conduction of the S1 and the S3 or the conduction of the S2 and the S4, wherein the voltage of the voltage regulating winding output between the first output end and the second output end of the voltage regulating circuit is 0, and the voltage output after the conventional winding of the transformer is connected with the voltage regulating circuit in series is U.
In the embodiment of the invention, when the voltage regulating transformer comprises a transformer and two voltage regulating circuits, the two voltage regulating circuits are connected in series and then connected in series with a secondary side winding of the transformer, and the output voltages of the two output ends after the two voltage regulating circuits are connected in series are nine-level voltages by controlling the on-off state of the switch module and the on-off state of the switch module.
As shown in figure 1, when the secondary side regular winding of the transformer is connected with two voltage regulating circuits, the two voltage regulating circuits form a double H-bridge structure, if the voltage at two ends of the secondary side regular winding of the transformer is U, when the A voltage regulating circuit in the two voltage regulating circuits is connected with the transformer in the forward direction, the voltage between the first output end and the second output end of the A voltage regulating circuit is U1, when the voltage regulating winding is connected with the transformer in the reverse direction, the voltage between the first output end and the second output end of the A voltage regulating circuit is-U1, the voltage between the first output end and the second output end of the A voltage regulating circuit is U1, -U1 and 0;B voltage regulating circuits are connected with the transformer in the forward direction, and when the voltage regulating winding is connected with the transformer in the reverse direction, the voltage between the first output end and the second output end of the B voltage regulating circuit is-U2, the voltage between the first output end and the second output end of the B voltage regulating circuit is-U1, the B voltage regulating circuit is-U2, the on-off state of the switching module in the two voltage regulating circuits is changed, the first output end and the B voltage regulating circuit is-U1, the voltage between the first output end and the second output end of the B voltage regulating circuit is-U2, the U2 is changed, the voltage between the first output end and the U2 is connected with the U2 in the voltage regulating circuit in the reverse direction, and the voltage between the first output end and the U2 is changed, the voltage between the U2 and the first output end of the U2 and the voltage regulating circuit is connected with the U2.
Further, when voltages between the first output end and the second output end of the voltage regulating circuit A of the two voltage regulating circuits shown in FIG. 1 are U1, -U1 and 0, and voltages between the first output end and the second output end of the voltage regulating circuit B are 3U1, -3U1 and 0, voltages output after the conventional winding on the secondary side of the transformer is connected with the two voltage regulating circuits in series can be continuously regulated between nine stages of voltages, and the output states of the multi-stage voltage output combination of the double H-bridge are shown in the following table.
In the embodiment of the invention, when the voltage regulating transformer comprises a transformer and three voltage regulating circuits, the three voltage regulating circuits are connected in series and then connected in series with a secondary side winding of the transformer, and the output voltage of two output ends after the three voltage regulating circuits are connected in series is twenty-seven-level voltage by controlling the on-off state of the switch module and the on-off state of the switch module.
When the voltage regulating transformer comprises three voltage regulating circuits, assuming that the voltages at two ends of a conventional winding at the secondary side of the transformer are U, when the A voltage regulating circuit in the three voltage regulating circuits is connected to the transformer in the forward direction, the voltage between the first output end and the second output end of the A voltage regulating circuit is U1, when the voltage regulating winding is connected to the transformer in the reverse direction, the voltage between the first output end and the second output end of the A voltage regulating circuit is-U1, by changing the on-off state of a switch module in the two voltage regulating circuits, the voltage between the first output end and the second output end of the A voltage regulating circuit is U1, -U1 and 0;B voltage regulating circuit is connected to the transformer in the forward direction, when the voltage regulating winding is connected to the transformer in the reverse direction, the voltage between the first output end and the second output end of the B voltage regulating circuit is-U2, and when the voltage between the first output end and the second output end of the B voltage regulating circuit is-U2 is changed, and the voltage between the first output end and the second output end of the C voltage regulating circuit is-U3 when the switch module in the two voltage regulating circuits is changed, and the voltage between the first output end and the first output end of the C3 is connected to the voltage regulating circuit is changed; the voltage output by the two output ends after the three voltage regulating circuits are connected in series can be U1+U2+U3、U2+U3、U2+U3-U1、U1+U3、U3、U3-U1、U3+U1-U2、U3-U2、U3-U2-U1、U1+U2、U2、U2-U1、U1、0、–(U1+U2+U3)、-(U2+U3)、-(U2+U3-U1)、-(U1+U3)、-U3、-(U3-U1)、-(U3+U1-U2)、-(U3-U2)、-(U3-U2-U1)、-(U1+U2)、-U2、-(U2-U1)、-U1,, so that by changing the on-off state of the switch modules in the three voltage regulating circuits, the voltage output after the secondary side conventional winding of the transformer is connected with the three voltage regulating circuits in series can be rapidly switched between twenty-seven voltage levels.
When the number of the voltage regulating circuits is three or more, the voltage amplitude of the two output ends after all the voltage regulating windings are connected to the transformer can be changed by changing the number of turns of each voltage regulating winding, so that voltage regulation of more stages is realized, for example, when the number of the voltage regulating circuits is three, the voltage amplitude ratio of the two output ends after all the voltage regulating windings are connected to the transformer can be 1:1:1 or 1:2:4, and more voltages can be regulated. Taking 3 voltage regulating circuits as an example, when the ratio of the voltage amplitudes of the two output ends after all the voltage regulating windings are connected into the transformer is 1:2:4 and the minimum voltage amplitude of the two output ends after all the voltage regulating windings are connected into the transformer is U, after the three voltage regulating circuits are connected in series, the total output voltage can be 7U, 6U, 5U, 4U, 3U, 2U, U, 0, -U, 2U, 3U, 4U, 5U, 6U and 7U for 15 gears, and when the ratio of the voltage amplitudes of the two output ends after all the voltage regulating windings are connected into the transformer is 1:3:9 and the minimum voltage amplitude of the two output ends after all the voltage regulating windings are connected into the transformer is U, the total output voltage can be 13U、12U、11U、10U、9U、8U、7U、6U、5U、4U、3U、2U、1U、0、-1U、-2U、-3U、-4U、-5U、-6U、-7U、-8U、-9U、-10U、-11U、-12U、-13U for 27 gears. Therefore, as can be seen from the above description, when the voltage regulating windings of the voltage regulating circuit are connected in series with more voltage regulating circuits, and the voltage magnitudes of the two output ends are more rated after all the voltage regulating windings of the voltage regulating circuit are connected to the voltage regulating circuit, the voltage of more rated can be output after the voltage regulating circuit is connected in series with the voltage regulating circuit.
The voltage regulating transformer provided by the embodiment of the invention has the advantages that the secondary side winding of the transformer is connected with at least one voltage regulating circuit, the voltage of the output end of the voltage regulating circuit is regulated by changing the on-off state of the switch module, and the voltage amplitude of the output end is regulated by changing the voltage amplitude of the voltage regulating winding when all the voltage regulating windings are connected into the transformer, so that multi-gear voltage regulation is realized, and the voltage amplitude of the transmission line of an alternating current system is controlled.
Example 2
The embodiment of the invention provides a power flow control system which is applied to occasions needing to carry out power flow control on an alternating current system, wherein the power flow control system comprises a controller 2, at least one converter 3 and a voltage regulating transformer 1 in the embodiment 1, wherein the voltage regulating transformer can be a single-phase voltage regulating transformer or a three-phase voltage regulating transformer, when the voltage regulating transformer is a single-phase transformer and the converter is a single-phase converter, one voltage regulating transformer and one converter are combined and then connected into a phase transmission line of the alternating current system, when the voltage regulating transformer is a three-phase transformer and the converter is a single-phase converter, the power flow control system formed by connecting one voltage regulating transformer and three converters is connected into the transmission line of the alternating current system, and when the voltage regulating transformer is a three-phase transformer and the converter is a three-phase converter, the power flow control system formed by connecting one voltage regulating transformer and one converter is connected into the transmission line of the alternating current system. As shown in fig. 4, when the voltage regulating transformer is a single-phase transformer, the converter is a single-phase converter, and the voltage regulating transformer includes two voltage regulating circuits, the converter is formed by two single-phase converter units, which is only an example, but not limited thereto.
The input side of the converter is connected with the primary side winding of the voltage regulating transformer, the output side of the converter is connected with the output end of the voltage regulating circuit of the secondary side of the voltage regulating transformer, and the converter is used for regulating the voltage amplitude and the phase of the alternating current system.
If the voltage regulating transformer is singly connected in series in the alternating current system, the input side of the current converter is connected with the primary side of the voltage regulating transformer, namely the current converter is connected with the transformer in parallel for taking energy, and the output side of the current converter is connected with the output end of the voltage regulating module of the secondary side of the voltage regulating transformer.
The controller is arranged on a power line of the alternating current system and is used for collecting voltages and currents of nodes and branches of installation points and preset adjacent ranges of the nodes and the branches, or receiving an upper-level dispatching instruction, and changing the voltages and the power flow of the alternating current system by coordinating the output voltage amplitude and the phase of the voltage regulating circuit and the converter.
The controller is used for collecting the voltage and current of the mounting points or nearby nodes (the nodes can comprise balance nodes, PQ nodes, PV nodes and the like), carrying out load flow calculation by utilizing the voltage and the current, and when the load flow calculation is abnormal, changing the voltage and the load flow of the alternating current system by controlling the output voltage amplitude and the phase of the current converter at the abnormal place and combining the output voltage amplitude of the voltage regulating transformer.
In a specific embodiment, as shown in fig. 4, when the voltage regulating transformer is a single-phase transformer, one end of a primary winding of the single-phase transformer is connected with any one phase transmission line of the ac system, the other end of the primary winding of the single-phase transformer and the self-coupling output end are connected with the input side of the converter, and one end of the output side of the converter is connected with the output end of the voltage regulating circuit of the secondary side of the single-phase transformer.
When the voltage regulating transformer is a single-phase transformer, the current converter is a single-phase current converter, the input side of the current converter is connected with the primary side of the voltage regulating transformer in parallel to obtain energy, so that the current converter is an active current converter, the output side of the current converter is connected with the output end of a voltage regulating circuit at the low potential end of the secondary side of the voltage regulating transformer, and one voltage regulating transformer and one current converter are combined and then are connected into a phase transmission circuit of an alternating current system.
The secondary side conventional winding of the transformer in the embodiment of the invention is not only connected in series with at least one voltage regulating module, but also can be connected in series with a converter at the low-voltage output end of the voltage regulating module, the converter at least consists of two converter units sharing buses, at least one converter unit is connected in parallel with the transformer winding to take energy to provide dynamic reactive compensation for the system, the voltage level of a node is stabilized, the alternating current output voltage output by the alternating current side of the converter unit at the output side of the converter is connected in series with the output end of the voltage regulating circuit, the converter has the capacity of quickly regulating the phase of small-capacity voltage amplitude, the capacity of quickly regulating the power flow in a large range can be realized in a point-to-surface combination way with the voltage regulating circuit, the voltage regulating range matched with the two-stage on-load voltage regulating and the active converter is shown as figure 5, in the figure, A is the output voltage amplitude of the power flow control system, and U tap is the output voltage vector of the power flow control system.
In a specific embodiment, the power flow control system further comprises at least one bypass switch module 4, each voltage regulating circuit and each current converter are connected with one bypass switch in parallel, the bypass switch module is used for rapidly cutting off fault points when any voltage regulating circuit or each current converter breaks down, or the output end of the voltage regulating circuit is connected with the current converter through the bypass switch module, and the bypass switch module is used for cutting off current loops of the voltage regulating circuit and the current converter when the voltage regulating circuit or the current converter breaks down.
As shown in fig. 6, the output end of the voltage regulating circuit is connected with the current converter through a bypass switch module 4, and the bypass switch module is used for cutting off the current loop of the voltage regulating circuit and the current converter when the voltage regulating circuit or the current converter fails. The bypass switch module has a specific structure shown in fig. 3, the bypass switch module in fig. 3 is a controllable thyristor switch for rapidly bypassing a fault point, and in addition, the bypass switch module can also comprise a mechanical switch for reliably bypassing the fault point, and a lightning arrester for protecting the overvoltage between the ends. When the voltage regulating circuit is positioned at the low potential end of the transformer, one end of the bypass switch module can be directly grounded, so that the bypass switch module is conducted to the transformer to have a stable and reliable grounding point. In addition, a specific connection mode of parallel connection of the voltage regulating circuit in the voltage regulating transformer in the power flow control system and the bypass switch module is shown in fig. 3.
In a specific embodiment, when the voltage regulating transformer is a three-phase transformer and the converter is a single-phase converter, the autotransformer output end of the primary winding of each phase of the three-phase transformer is connected with one end of the input side of one converter, the other ends of the input sides of the three converters are connected with each other, and one end of the output side of each converter is connected with the output end of the voltage regulating circuit of the corresponding secondary side of the three-phase transformer.
When the voltage regulating transformer is a three-phase transformer and the converter is a single-phase converter, each phase of the primary side of the three-phase transformer is connected with the input side of one converter, one converter is composed of at least two single-phase converter units which are connected back to back, the single-phase converter units can be full-bridge converter circuits, half-bridge converter circuits and other converter circuits, one end of the alternating current side of the single-phase converter unit of each converter input side is connected with one phase of the primary side of the transformer in parallel to take energy, the other end of the alternating current side of the single-phase converter unit of each converter input side is connected with each other to form a neutral point, the output voltage of the alternating current side of one converter unit of each converter output side is connected with the output end of the voltage regulating circuit of the corresponding phase of the secondary side of the three-phase transformer, and the output end of the voltage regulating circuit is connected with an alternating current system circuit when the converter output side is connected with one end of the conventional winding of the three-phase transformer.
In a specific embodiment, as shown in fig. 7, the power flow control system further includes:
When the voltage regulating transformer is a three-phase transformer and the current converter is a three-phase current converter, the self-coupling output end of the primary side winding of each phase of the three-phase transformer is correspondingly connected with the input side of the current converter, each phase of the output side of the current converter is connected with one end of the primary side winding of one additional transformer, the other end of the primary side winding of each additional transformer is interconnected, one end of the secondary side winding of each additional transformer is respectively connected with the low-potential output end or the high-potential output end of the voltage regulating circuit of the corresponding secondary side of the three-phase transformer, and the other ends of the secondary side windings of the three additional transformers are interconnected.
When the voltage regulating transformer is a three-phase transformer and the converter is a three-phase converter, the converter is composed of at least two three-phase converter units connected back to back, and the three-phase converter units can be a three-phase rectifying circuit or a three-phase inverter circuit. As shown in fig. 7, the primary side of the three-phase transformer is connected in parallel to the transmission line of the ac system, and the three-phase secondary side line-in ends of the three-phase transformer are respectively connected in series with the regular windings of the respective phases, the voltage regulating circuit and the adjustable ac voltage output from the output side of the converter.
When one end of each secondary side winding of each additional transformer is connected with the low-potential output end of the voltage regulating circuit of the corresponding phase secondary side of the three-phase transformer, one end of each phase secondary side winding of the three-phase transformer is connected with the corresponding alternating current system transmission line, the other end of each phase secondary side winding of the three-phase transformer is connected with the voltage regulating circuit, and the high-potential output end of the voltage regulating circuit of the corresponding phase secondary side of the three-phase transformer is connected with the corresponding alternating current system transmission line.
The three-phase alternating current end of the input side of the three-phase converter is connected with a transformer in parallel to dynamically compensate reactive power of a system node, the three-phase alternating current voltage output by the output side of the three-phase converter is connected to the primary side of an additional transformer, the additional transformer is an additional three-phase transformer, the secondary winding of the additional transformer is of a three-single-phase structure and is provided with 6 ports, the three-phase alternating current voltage output by the converter is converted into three single-phase voltages, the three single-phase voltages are connected with the high-potential output end or the low-potential output end of the corresponding phase of the three-phase transformer, the additional transformer is connected with the low-potential output end, and when one end of the secondary side of the additional transformer is connected with the corresponding phase low potential of the secondary side of the three-phase transformer, the other end of the secondary side of the additional transformer is connected in a star-shaped or triangle wiring mode.
As shown in fig. 8, when one end of each secondary winding of the additional transformer is connected to the high-potential output end of the voltage regulating circuit of the corresponding secondary side of the three-phase transformer, one end of each secondary winding of the three-phase transformer is connected to the ground, the other end of each secondary winding of the three-phase transformer is connected to the corresponding secondary winding of the additional transformer, the low-potential output end of the voltage regulating circuit of the secondary side of the corresponding phase of the three-phase transformer is connected to the corresponding transmission line of the ac system, and when one end of the secondary side of the additional transformer is connected to the high-potential output end of the corresponding phase of the secondary side of the three-phase transformer, the other ends of the secondary sides of the additional transformers are interconnected in a star-shaped or triangle-shaped connection mode. The secondary sides of the additional transformers in fig. 8 are interconnected in a delta connection, but may also be interconnected in a star connection.
The power flow control system provided by the embodiment of the invention introduces the energy taking of the parallel connection of the converter and the primary side of the transformer on the basis of the voltage regulating transformer, wherein the output end of the converter is connected in series with the secondary side of the transformer, and the parallel reactive compensation of the alternating current system and the control of the voltage amplitude and the phase of the transmission line of the alternating current system are realized by controlling the running state of the converter, so that the power flow control capability of the alternating current system is enhanced.
It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. And obvious variations or modifications thereof are contemplated as falling within the scope of the present invention.
Claims (9)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010550443.3A CN111525583B (en) | 2020-06-16 | 2020-06-16 | Voltage regulating transformer and power flow control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010550443.3A CN111525583B (en) | 2020-06-16 | 2020-06-16 | Voltage regulating transformer and power flow control system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111525583A CN111525583A (en) | 2020-08-11 |
| CN111525583B true CN111525583B (en) | 2025-09-16 |
Family
ID=71909928
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010550443.3A Active CN111525583B (en) | 2020-06-16 | 2020-06-16 | Voltage regulating transformer and power flow control system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111525583B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113497447B (en) * | 2021-01-09 | 2024-01-09 | 华北电力大学（保定） | A three-phase electromagnetic series transmission line bidirectional voltage adaptive adjustment device |
| CN112821408B (en) * | 2021-01-09 | 2024-01-09 | 华北电力大学（保定） | A bidirectional voltage adaptive adjustment method for electromagnetic series transmission lines |
| CN112821407B (en) * | 2021-01-09 | 2024-01-09 | 华北电力大学（保定） | A single-phase or three-phase electromagnetic series bidirectional voltage regulation topology circuit |
| CN113936899B (en) * | 2021-10-15 | 2026-04-17 | 广东电网有限责任公司广州供电局 | A method and apparatus for adjusting large current using a tap changer |
| CN114884071A (en) * | 2022-06-17 | 2022-08-09 | 国网智能电网研究院有限公司 | Flexible power transformer |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017000735A1 (en) * | 2015-07-01 | 2017-01-05 | 全球能源互联网研究院 | Controlled phase shift transmitter with short-circuit current limiting function |
| CN107947173A (en) * | 2017-12-20 | 2018-04-20 | 南京南瑞继保电气有限公司 | A kind of series compensator and control method |
| CN109038606A (en) * | 2018-08-08 | 2018-12-18 | 全球能源互联网研究院有限公司 | A kind of on-load regulator transformer and Unified Power Flow control system |
| CN212518415U (en) * | 2020-06-16 | 2021-02-09 | 全球能源互联网研究院有限公司 | Voltage regulating transformer and power flow control system |
-
2020
- 2020-06-16 CN CN202010550443.3A patent/CN111525583B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017000735A1 (en) * | 2015-07-01 | 2017-01-05 | 全球能源互联网研究院 | Controlled phase shift transmitter with short-circuit current limiting function |
| CN107947173A (en) * | 2017-12-20 | 2018-04-20 | 南京南瑞继保电气有限公司 | A kind of series compensator and control method |
| CN109038606A (en) * | 2018-08-08 | 2018-12-18 | 全球能源互联网研究院有限公司 | A kind of on-load regulator transformer and Unified Power Flow control system |
| CN212518415U (en) * | 2020-06-16 | 2021-02-09 | 全球能源互联网研究院有限公司 | Voltage regulating transformer and power flow control system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111525583A (en) | 2020-08-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111525583B (en) | Voltage regulating transformer and power flow control system | |
| Zhang et al. | Review of modular multilevel converter based multi-terminal HVDC systems for offshore wind power transmission | |
| US20200220355A1 (en) | Chained multi-port grid-connected interface apparatus and control method | |
| CN113726136B (en) | conversion device | |
| US20150029764A1 (en) | Transformer-less unified power flow controller | |
| CN109873568B (en) | A multi-DC port converter and control method | |
| CN106452136A (en) | Multi-port power electronic converter for energy internet | |
| CN113726137B (en) | conversion device | |
| CN118100260B (en) | Flexible alternating current interconnection device and control method | |
| CN112952845B (en) | A low-frequency power transmission system with transformer isolation and control method thereof | |
| CN107039980B (en) | A high-voltage DC power flow controller | |
| EP2781014A1 (en) | Ac/dc multicell power converter for dual terminal hvdc connection | |
| CN101856979A (en) | A common-phase power supply device for electrified railway | |
| Kadandani et al. | Solid state transformer: An overview of circuit configurations and applications | |
| CN105870927B (en) | A unified power flow controller with multiple operation modes | |
| CN119253717B (en) | Multi-port flexible interconnection device, alternating current-direct current hybrid power transmission system and alternating current transformer substation | |
| CN107947222A (en) | DC fan power transmission system | |
| WO2013013858A1 (en) | An apparatus for controlling the electric power transmission in a hvdc power transmission system | |
| CN119543335A (en) | A grid strength support equipment for high-voltage DC busbar direct-mounted energy storage | |
| CN111313424A (en) | Three-phase four-wire system universal power quality controller and control method thereof | |
| CN212518415U (en) | Voltage regulating transformer and power flow control system | |
| CN206908254U (en) | Intensive deicing device constant current, constant pressure modularization dynamic passive compensation part | |
| CN104184356B (en) | A kind of power model group of three-phase power electronic transformer | |
| CN201956688U (en) | Movable static synchronous compensator with modular structure | |
| CN210821908U (en) | High-speed railway load characteristic adjusting device based on modularization multi-level |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |