CN106130021B - T-shaped hybrid flexible tuning device - Google Patents
T-shaped hybrid flexible tuning device Download PDFInfo
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- CN106130021B CN106130021B CN201610462950.5A CN201610462950A CN106130021B CN 106130021 B CN106130021 B CN 106130021B CN 201610462950 A CN201610462950 A CN 201610462950A CN 106130021 B CN106130021 B CN 106130021B
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- 230000001052 transient effect Effects 0.000 claims abstract description 31
- 230000001939 inductive effect Effects 0.000 claims abstract description 26
- 230000001629 suppression Effects 0.000 claims abstract description 23
- 239000003990 capacitor Substances 0.000 claims description 14
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—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
- H02J3/01—Arrangements for reducing harmonics or ripples
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—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
- H02J3/1835—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control
- H02J3/1842—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control wherein at least one reactive element is actively controlled by a bridge converter, e.g. active filters
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- 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
- Y02E40/10—Flexible AC transmission systems [FACTS]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- 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
- Y02E40/40—Arrangements for reducing harmonics
Abstract
The invention provides a T-shaped hybrid flexible tuning device, which comprises a static synchronous compensator STATCOM and/or a static synchronous series compensator SSSC; the static synchronous compensator STATCOM is connected in parallel to the power transmission line between the two inductive compensation units, and the static synchronous series compensator SSSC is connected in series to the power transmission line at one side of the inductive compensation units. Compared with the prior art, the T-shaped hybrid flexible tuning device provided by the invention can flexibly adjust output to adapt to the changes of the structure, parameters and operation modes of the power transmission line, ensures that the power transmission line presents the characteristic of a half-wavelength power transmission system, and simultaneously has the functions of power factor compensation, flexible grid-connected control, transient overvoltage suppression, steady-state voltage control and the like.
Description
Technical Field
The invention relates to the technical field of half-wavelength alternating current transmission, in particular to a T-shaped hybrid flexible tuning device.
Background
Half-wave ac transmission (Half Wavelength AC Transmission, HWACT) refers to ultra-long three-phase ac transmission with an electrical distance of approximately 1 power frequency half-wave, i.e., 3000km (50 Hz) or 2600km (60 Hz). With the increasing demand for ultra-long-distance and high-power transmission, half-wavelength ac transmission technology, especially ultra-high voltage half-wavelength ac transmission, is receiving much attention and research again. The half-wavelength alternating current circuit under the lossless condition is similar to an ideal transformer with the transformation ratio of-1.0, and the head end voltage and the tail end voltage are the same in size and opposite in phase. Meanwhile, the half-wavelength alternating current transmission technology has the following advantages: firstly, the power factor of the half-wavelength alternating current transmission line is relatively high, and under the condition that the transmission distance is equal to or slightly more than half wavelength, the structure of the half-wavelength alternating current transmission line is simpler than that of the existing ultra-long-distance alternating current and direct current transmission system; furthermore, the manufacture of ac transmission equipment is simpler and more economical for developing countries than the introduction, operation and maintenance of the converter devices.
The half-wavelength alternating current transmission line is limited by objective conditions, and the natural length of an actual line is difficult to be exactly half wavelength. When the length of the line is less than half wavelength, a tuning circuit or a compensation circuit is needed to manually compensate the electrical length of the transmission line so as to achieve the purpose of the artificial half-wavelength alternating current transmission line. Currently, the existing half-wavelength ac transmission compensation scheme is based on passive network to perform transmission line tuning, such as the T-type tuning device shown in fig. 1 and the pi-type tuning device shown in fig. 2. However, the two tuning schemes limit the development and application of half-wavelength alternating current transmission technology to a certain extent, firstly, the adaptability of the passive tuning circuit to system structure, operation mode or parameter change is relatively poor, and the half-wavelength characteristic is easy to lose; secondly, when a short circuit fault occurs in the passive tuning circuit, resonance is easy to occur, overvoltage with high amplitude is generated, and the line and equipment are required to be improved in corresponding insulation requirements, or corresponding overvoltage limiting measures are required to be installed to restrain the overvoltage of the line.
Disclosure of Invention
Aiming at the defects of a passive tuning circuit in the prior art, the invention provides a T-shaped hybrid flexible tuning device.
The technical scheme of the invention is as follows:
the tuning device is arranged in an alternating current transmission system and comprises a capacitive compensation unit and two inductive compensation units; one end of the capacitive compensation unit is connected between the two inductive compensation units in series, and the other end of the capacitive compensation unit is grounded;
the tuning device comprises a static synchronous compensator STATCOM and/or a static synchronous series compensator SSSC;
and the static synchronous compensator STATCOM is connected in parallel to the transmission line between the two inductive compensation units, and the static synchronous series compensator SSSC is connected in series to the transmission line at one side of the inductive compensation units.
The invention further provides a preferable technical scheme that: the combined configuration mode of the static synchronous compensator STATCOM and the static synchronous series compensator SSSC in the tuning device comprises the following steps:
the first combined configuration mode: the tuning means comprise only one set of static synchronous series compensators SSSC;
the second combination configuration mode: the tuning device only comprises a group of static synchronous compensators STATCOM;
third combined configuration mode: the tuning device comprises a group of static synchronous series compensators SSSC and a group of static synchronous compensators STATCOM;
fourth combined configuration mode: the tuning device comprises two groups of static synchronous series compensators SSSCs;
fifth combination configuration mode: the tuning means comprise two sets of static synchronous series compensators SSSC and a set of static synchronous compensators STATCOM.
The invention further provides a preferable technical scheme that: the parallel connection mode of the static synchronous compensator STATCOM connected to the power transmission line comprises the following steps:
the static synchronous compensator STATCOM is directly connected in parallel to the power transmission line; or,
the static synchronous compensator STATCOM is connected in parallel to the power transmission line through a transformer, and the capacity output quantity of the static synchronous compensator STATCOM is increased.
The invention further provides a preferable technical scheme that: the serial connection mode of the static synchronous serial compensator SSSC to the power transmission line comprises the following steps:
the SSSC is directly connected in series with the power transmission line; or,
the SSSC is connected in series with the power transmission line through a transformer, and the inductive output quantity of the SSSC is reduced.
The invention further provides a preferable technical scheme that: when the tuning device is installed in an alternating current transmission system, the configuration mode comprises the following steps:
a transmitting end arranged on the alternating current circuit; or,
the receiving end is configured on the alternating current circuit; or,
the power supply device is arranged at a transmitting end and a receiving end of the alternating current circuit; or,
is arranged in the middle section of the alternating current circuit.
The invention further provides a preferable technical scheme that:
when the tuning device is configured at the transmitting end of the alternating current line, flexible tuning control, flexible grid-connected control, power factor compensation, transient overvoltage suppression and steady-state voltage control are carried out on the alternating current transmission system;
when the tuning device is configured at the receiving end of the alternating current line, flexible tuning control, flexible grid-connected control, transient overvoltage suppression and steady-state voltage control are carried out on the alternating current transmission system;
when the tuning device is configured in the middle section of the alternating current line, flexible tuning control, transient overvoltage suppression and steady-state voltage control are performed on the alternating current transmission system.
The invention further provides a preferable technical scheme that: the tuning device carries out flexible tuning control on the alternating current transmission system to enable the alternating current transmission system to meet the requirements of the half-wavelength alternating current transmission system, and the tuning device comprises:
equivalent the output of the static synchronous series compensator SSSC to a series inductance/series reactance of the ac transmission system; equivalent the output of the static synchronous compensator STATCOM as a parallel capacitor of the alternating current transmission system;
controlling the static synchronous series compensator SSSC and the inductive compensation unit to jointly output an inductance value required by the half-wavelength alternating current transmission system; and controlling the static synchronous compensator STATCOM and the capacitive compensation unit to jointly output a capacitance value required by the half-wavelength alternating current transmission system.
The invention further provides a preferable technical scheme that: when the line structure, parameters and/or operation modes of the alternating current transmission system are changed, the inductance value and the capacitance value of the alternating current transmission system are enabled to meet the requirements of the half-wavelength alternating current transmission system by adjusting the equivalent inductance value output by the static synchronous series compensator SSSC and the equivalent capacitance value output by the static synchronous compensator STATCOM.
The invention further provides a preferable technical scheme that: after the tuning device flexibly tunes the alternating current power transmission system to meet the requirement of the half-wavelength alternating current power transmission system, flexible grid-connected control, power factor compensation, transient overvoltage suppression and steady-state voltage control are performed on the alternating current power transmission system.
The invention further provides a preferable technical scheme that: the tuning device comprises two groups of static synchronous series compensators SSSC and a group of static synchronous compensators STATCOM, and the device for flexibly controlling grid connection of an alternating current transmission system comprises the following steps:
the output of the static synchronous series compensator SSSC far away from the grid connection is equivalent to a series inductance/series reactance, the output of the static synchronous series compensator SSSC close to the grid connection is equivalent to a series voltage, and the equivalent voltage value output by the static synchronous series compensator SSSC is controlled so that the voltages of two AC power supplies connected in the grid are identical and the phases are identical;
when the equivalent voltage value output by the static synchronous series compensator SSSC close to the grid connection position reaches the maximum value, the output of the static synchronous series compensator SSSC far away from the grid connection position is adjusted to be equivalent to one series voltage, and the two static synchronous series compensatorSSSCs jointly control the AC power supply to grid connection.
The invention further provides a preferable technical scheme that: in the process of flexible grid-connected control of the alternating current transmission system by the tuning device, the tuning device comprises the following steps:
when the grid connection of the alternating current transmission system is completed and the transient operation is transited to the steady operation, the output of the static synchronous series compensator SSSC is equivalent to a series inductance/series reactance, and the static synchronous series compensator SSSC and the inductive compensation unit are controlled to jointly output the inductance value required by the half-wavelength alternating current transmission system;
and in the process of grid connection of the alternating current transmission system and transition from transient operation to steady operation, adjusting an equivalent capacitance value output by the static synchronous compensator STATCOM so as to reduce disturbance at the grid connection.
The invention further provides a preferable technical scheme that: the flexible grid connection mode of the tuning device comprises the following steps:
after the transmitting end alternating current power supply is connected with the alternating current power transmission system, the alternating current power transmission system is connected with the receiving end alternating current power supply in a grid mode;
or,
after the receiving end alternating current power supply is connected into the alternating current power transmission system, the alternating current power transmission system is connected with the transmitting end alternating current power supply in a grid mode.
The invention further provides a preferable technical scheme that: the tuning device is arranged at the transmitting end of the alternating current line, and the power factor compensation of the alternating current transmission system comprises the following steps:
and (3) equivalent output of the static synchronous compensator STATCOM is equivalent to a parallel capacitor, and the equivalent capacitance value of the output of the static synchronous compensator STATCOM is controlled to compensate reactive power of an alternating current transmission system.
The invention further provides a preferable technical scheme that: the tuning device for performing transient overvoltage suppression on an alternating current transmission system comprises the following steps:
and (3) equivalent the output of the static synchronous compensator STATCOM to be a parallel reactance, and controlling the static synchronous compensator STATCOM to absorb reactive power of an alternating current transmission system so as to inhibit power frequency overvoltage of a line.
The invention further provides a preferable technical scheme that: the tuning device for steady-state voltage control of an alternating current transmission system comprises:
when the line voltage of the alternating current transmission system is lower, the output of the static synchronous compensator STATCOM is equivalent to a parallel capacitor, and the equivalent capacitance value output by the static synchronous compensator STATCOM is controlled to compensate reactive power of the alternating current transmission system so as to support the line voltage;
when the line voltage of the alternating current transmission system is higher, the output of the static synchronous compensator STATCOM is equivalent to a parallel capacitor with a smaller capacitance value or equivalent to a parallel inductor/reactance, and the equivalent capacitance value or equivalent inductance value output by the static synchronous compensator STATCOM is controlled to compensate the reactive power of the alternating current transmission system so as to support the line voltage.
The invention further provides a preferable technical scheme that: the output quantity of the static synchronous compensator STATCOM comprises a basic output quantity and an additional output quantity;
determining the basic output quantity according to the requirement of the static synchronous compensator STATCOM on flexible tuning control of the alternating current transmission system and the parallel connection mode of the static synchronous compensator STATCOM to the alternating current transmission system;
and determining the additional output quantity according to the requirements of the static synchronous compensator STATCOM on flexible grid-connected control, power factor compensation, transient overvoltage suppression and steady-state voltage control of the alternating current transmission system.
The invention further provides a preferable technical scheme that: the output of the static synchronous series compensator SSSC includes a base output and an additional output;
determining the basic output quantity according to the requirement of the static synchronous series compensator SSSC on flexible tuning control of the alternating current transmission system and the series connection mode of the static synchronous series compensator SSSC connected to the alternating current transmission system;
and carrying out flexible grid connection control on the alternating current transmission system according to the SSSC to control the additional output quantity.
The invention further provides a preferable technical scheme that: when the tuning means comprise two sets of static synchronous series compensators SSSC, the outputs of the two sets are identical or different.
Compared with the closest prior art, the invention has the beneficial effects that:
1. the T-shaped hybrid flexible tuning device provided by the invention has the advantages that the static synchronous compensator STATCOM and the static synchronous series compensator SSSC can flexibly adjust respective outputs so as to adapt to the changes of the structure, parameters and operation modes of a power transmission line, ensure that the power transmission line presents the characteristics of a half-wavelength power transmission system, and simultaneously have the functions of power factor compensation, flexible grid-connected control, transient overvoltage suppression, steady-state voltage control and the like;
2. compared with a common grid-connected mode of a power system, the T-shaped hybrid flexible tuning device provided by the invention has the advantages that the voltage and the phase of a half-wavelength power transmission line can be flexibly adjusted through the static synchronous series compensator SSSC and the static synchronous compensator STATCOM, so that the flexible grid-connection only needs to pay attention to the voltage phase sequence and the frequency, the workload of increasing the voltage and the phase of two alternating current systems/alternating current power supplies to be grid-connected is reduced, and the technical requirement of grid connection is reduced.
Drawings
Fig. 1: a T-tuner schematic;
fig. 2: a pi-type tuning device schematic;
fig. 3: the embodiment of the invention discloses a schematic diagram of a T-shaped hybrid flexible tuning device;
fig. 4: in the embodiment of the invention, the T-shaped hybrid flexible tuning device is configured on a schematic diagram of a transmitting end and a receiving end of an alternating current circuit;
fig. 5: in the embodiment of the invention, the T-shaped hybrid flexible tuning device is configured in the middle section of the alternating current circuit.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. 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.
The following describes a T-shaped hybrid flexible tuning device according to an embodiment of the present invention with reference to the accompanying drawings.
Fig. 3 is a schematic diagram of a T-type hybrid flexible tuning device according to an embodiment of the present invention, where the tuning device includes a capacitive compensation unit, two inductive compensation units, a static synchronous compensator STATCOM and/or a static synchronous series compensator SSSC, and one end of the capacitive compensation unit is connected between the two inductive compensation units connected in series, and the other end is grounded. Wherein,
the capacitive compensation unit comprises a parallel capacitor, and the inductive compensation unit comprises a series inductor;
the static synchronous compensator STATCOM is connected in parallel to a power transmission line between the two inductive compensation units;
the static synchronous series compensator SSSC is connected in series into the transmission line at one side of the inductive compensation unit.
The static synchronous compensator STATCOM and the static synchronous series compensator SSSC in the tuning device comprise five combination configuration modes, and the combination configuration modes specifically comprise:
the first combined configuration mode: the tuning means comprise only one set of static synchronous series compensators SSSC;
the second combination configuration mode: the tuning means comprise only one set of static synchronous compensators STATCOM;
third combined configuration mode: the tuning device comprises a group of static synchronous series compensators SSSC and a group of static synchronous compensators STATCOM;
fourth combined configuration mode: the tuning device comprises two groups of static synchronous series compensators SSSCs;
fifth combination configuration mode: the tuning means comprise two sets of static synchronous series compensators SSSC and a set of static synchronous compensators STATCOM.
The parallel connection mode of the static synchronous compensator STATCOM in the invention comprises the following steps:
(1) The static synchronous compensator STATCOM is directly connected in parallel to the power transmission line.
(2) The static synchronous compensator STATCOM is connected in parallel to the power transmission line through a transformer, and the capacity output quantity of the static synchronous compensator STATCOM is increased. In this embodiment, the voltage class of the half-wavelength transmission line is higher, the static synchronous compensator STATCOM is connected to the transmission line through the step-up transformer, and meanwhile, after the static synchronous compensator STATCOM is connected to the transmission line through the transformer, the short-circuit impedance of the transformer is equivalent to a value of reducing the parallel capacitance, so that the capacity output of the static synchronous compensator STATCOM needs to be correspondingly increased.
The serial connection mode of the SSSC of the static synchronous serial compensator in the invention comprises the following steps:
(1) The static synchronous series compensator SSSC is directly connected in series to the transmission line.
(2) The static synchronous series compensator SSSC is connected in series to the power transmission line through a transformer, and the inductive output quantity of the static synchronous series compensator SSSC is reduced. In this embodiment, the line current of the half-wavelength transmission line is larger, the SSSC is connected to the transmission line through the transformer, and when the SSSC is connected to the transmission line through the transformer, the leakage inductance of the transformer increases the value of the series inductance, so that the inductive output of the SSSC can be reduced correspondingly.
The tuning device is arranged in an alternating current transmission system and comprises five configuration modes, and the configuration modes are as follows:
(1) Is disposed at the transmitting end of the AC line.
In this embodiment, when the tuning device is configured at the transmitting end of the ac line, flexible tuning control, flexible grid-connected control, power factor compensation, transient overvoltage suppression, and steady-state voltage control are performed on the ac power transmission system.
(2) Is disposed at the receiving end of the AC line.
Fig. 4 is a schematic diagram of a T-type hybrid flexible tuning device configured at a transmitting end and a receiving end of an ac line in an embodiment of the present invention, where in the embodiment, when the tuning device is configured at the receiving end of the ac line, flexible tuning control, flexible grid-connected control, transient overvoltage suppression, and steady-state voltage control are performed on an ac power transmission system.
(3) Is disposed at the transmitting end and the receiving end of the AC line.
(4) Is arranged in the middle section of the alternating current circuit.
Fig. 5 is a schematic diagram of a T-type hybrid flexible tuning device configured in the middle section of an ac line according to an embodiment of the present invention, where flexible tuning control, transient overvoltage suppression, and steady-state voltage control are performed on an ac power transmission system when the tuning device is configured in the middle section of the ac line as shown in the drawing.
After the tuning device flexibly tunes the alternating current transmission system to meet the requirement of the half-wavelength alternating current transmission system, the flexible grid-connected control, the power factor compensation, the transient overvoltage suppression and the steady-state voltage control are performed on the alternating current transmission system. The following describes flexible tuning control, flexible grid-connected control, power factor compensation, transient overvoltage suppression and steady-state voltage control, respectively.
1. Flexible tuning control
In this embodiment, the tuning device performs flexible tuning control on the ac power transmission system to make the ac power transmission system meet the requirement of the half-wavelength ac power transmission system, and specifically includes:
step S11: performing inductive regulation on the SSSC, and enabling the output of the SSSC to be equivalent to a series inductance/series reactance of an AC transmission system; performing capacitive adjustment on a static synchronous compensator STATCOM, and enabling output of the STATCOM to be equivalent to a parallel capacitor of an alternating current transmission system;
step S12: controlling a static synchronous series compensator SSSC and an inductive compensation unit to jointly output an inductance value required by the half-wavelength alternating current transmission system; and controlling the static synchronous compensator STATCOM and the capacitive compensation unit to jointly output a capacitance value required by the half-wavelength alternating current transmission system.
It should be noted that:
when the line structure, parameters and/or operation modes of the alternating current transmission system are changed, the total capacitance and inductance meet the tuning of the changed half-wavelength alternating current transmission system by adjusting the equivalent inductance value output by the static synchronous series compensator SSSC and the equivalent capacitance value output by the static synchronous compensator STATCOM, and finally the whole system presents the characteristic of the half-wavelength alternating current transmission system, namely flexible tuning is realized.
2. Flexible grid-connected control
The grid connection of the power system mainly comprises four conditions, specifically:
(1) The frequency of the two ac systems/ac sources connected to the grid is the same.
(2) The voltage of the two AC systems/AC power supplies connected in the grid is the same, and the maximum deviation is within 5%.
(3) The phase sequences of the two ac systems/ac power supplies connected in the grid are the same.
(4) The voltage phases of the two ac systems/ac power sources connected in the grid are the same.
The flexible grid-tie control will be described below with reference to the tuning device shown in fig. 3. The ac power transmission system in this embodiment is set to satisfy the grid-connected conditions (1) and (3) of the power system, and the tuning device includes two sets of static synchronous series compensators SSSC and one set of static synchronous compensators STATCOM. The device carries out flexible grid-connected control on an alternating current transmission system, and specifically comprises the following steps:
and performing inductive regulation on the SSSC far away from the grid connection position, and equivalently converting the output of the SSSC into a series inductance/series reactance, wherein the output of the SSSC close to the grid connection position is equivalently a series voltage, and controlling the equivalent voltage value output by the SSSC so that the voltages of the two AC power supplies connected in the grid are identical and the phases are identical. In this embodiment, after an equivalent voltage output by the static synchronous series compensator SSSC is added to one ac system/ac power supply to be connected, the voltage phases of the two ac systems/ac power supplies to be connected are identical, so that four conditions of grid connection of the power system are satisfied.
The flexible grid connection mode of the tuning device in this embodiment includes:
after the transmitting end alternating current power supply is connected with the alternating current power transmission system, the alternating current power transmission system is connected with the receiving end alternating current power supply in a grid mode; or after the receiving end alternating current power supply is connected into the alternating current power transmission system, the alternating current power transmission system is connected with the transmitting end alternating current power supply in a grid mode.
It should be noted that:
(1) When the equivalent voltage value of the SSSC output by the SSSC close to the grid connection position reaches the maximum value, the SSSC output by the SSSC far away from the grid connection position is adjusted to be equivalent to a series voltage, and the SSSC of the two SSSs jointly control the grid connection of the AC power supply.
(2) When the grid connection of the alternating current transmission system is completed and the transient operation is transited to the steady operation, the output of the static synchronous series compensator SSSC is equivalent to a series inductance/series reactance, and the static synchronous series compensator SSSC and the inductance compensation unit are controlled to jointly output an inductance value required by the half-wavelength alternating current transmission system;
and in the process of grid connection of the alternating current transmission system and transition from transient operation to steady operation, adjusting an equivalent capacitance value output by a static synchronous compensator STATCOM so as to reduce disturbance at the grid connection.
In the embodiment, compared with a common grid-connected mode of a power system, the flexible grid-connected control can flexibly adjust the voltage and the phase of the half-wavelength power transmission line through the static synchronous series compensator SSSC and the static synchronous compensator STATCOM. Therefore, the flexible grid connection only needs to pay attention to the voltage phase sequence and the frequency, thereby reducing the workload increased by adjusting the same voltage and consistent phase of two alternating current systems/alternating current power supplies to be connected, and reducing the technical requirement of grid connection.
3. Power factor compensation
Next, the flexible grid-connected control will be described with reference to the tuning device shown in fig. 3, and the tuning device is set to be mounted on the transmitting end of the ac line. The device for carrying out power factor compensation on the alternating current transmission system comprises the following steps:
and (3) the output of the static synchronous compensator STATCOM is equivalent to a parallel capacitor, and the equivalent capacitance value of the output of the static synchronous compensator STATCOM is controlled to compensate the reactive power of the alternating current transmission system.
It should be noted that: when the power factor of the transmitting end alternating current power supply changes, the output of the static synchronous compensator STATCOM can be adjusted, so that the parallel capacitor and the static synchronous compensator STATCOM simultaneously meet the requirements of flexible tuning and power factor compensation.
4. Transient overvoltage suppression
The flexible grid-tie control will be described below with reference to the tuning device shown in fig. 3. The device for suppressing the transient overvoltage of the alternating current transmission system comprises the following steps:
and (3) equivalent the output of the static synchronous compensator STATCOM as a parallel reactance, and controlling the static synchronous compensator STATCOM to absorb reactive power of the alternating current transmission system so as to inhibit power frequency overvoltage of the line.
For example, when the power frequency overvoltage is caused by single-phase grounding fault of the alternating-current power transmission system or three-phase load shedding and other working conditions at the tail end, the transient overvoltage can be restrained through the tuning device.
5. Steady state voltage control
The flexible grid-tie control will be described below with reference to the tuning device shown in fig. 3. The device for controlling the steady-state voltage of the alternating-current power transmission system comprises the following steps:
when the line voltage of the alternating current transmission system is lower, the output of the static synchronous compensator STATCOM is equivalent to a parallel capacitor, and the equivalent capacitance value output by the static synchronous compensator STATCOM is controlled to compensate reactive power of the alternating current transmission system so as to support the line voltage;
when the line voltage of the alternating current transmission system is higher, the output of the static synchronous compensator STATCOM is equivalent to a parallel capacitor with a smaller capacitance value or equivalent to a parallel inductor/reactance, and the equivalent capacitance value or equivalent inductance value output by the static synchronous compensator STATCOM is controlled to compensate the reactive power of the alternating current transmission system so as to support the line voltage.
The output quantity of the static synchronous compensator STATCOM in the invention includes a basic output quantity and an additional output quantity, wherein:
and determining the basic output quantity according to the requirement of the static synchronous compensator STATCOM on flexible tuning control of the alternating current transmission system and the parallel connection mode of the alternating current transmission system.
And determining the additional output quantity according to the requirements of the static synchronous compensator STATCOM on flexible grid-connected control, power factor compensation, transient overvoltage suppression and steady-state voltage control of the alternating current transmission system. The additional output may be determined, for example, by the requirements of any one, two, three, or four of flexible grid-tie control, power factor compensation, transient overvoltage suppression, and steady-state voltage control.
It should be noted that: the two sets of static synchronous series compensators SSSC of the tuning arrangement shown in fig. 3 have the same or different outputs.
The output of the static synchronous series compensator SSSC in the present invention includes a base output and an additional output, wherein:
and determining the basic output quantity according to the requirement of the static synchronous series compensator SSSC on flexible tuning control of the alternating current transmission system and the series connection mode of the static synchronous series compensator SSSC connected to the alternating current transmission system.
And carrying out flexible grid connection control on the alternating current transmission system according to the SSSC to control the additional output quantity.
The static synchronous compensator STATCOM and the static synchronous series compensator SSSC of the T-shaped hybrid flexible tuning device provided by the invention can flexibly adjust respective outputs to adapt to the changes of the structure, parameters and operation modes of a power transmission line, ensure that the power transmission line presents the characteristics of a half-wavelength power transmission system, and simultaneously can also be provided with passive tuning circuits such as power factor compensation, flexible grid-connected control, transient overvoltage suppression, steady-state voltage control and the like.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
Claims (15)
1. A T-shaped hybrid flexible tuning device which is arranged in an alternating current transmission system; the tuning device comprises a capacitive compensation unit and two inductive compensation units; one end of the capacitive compensation unit is connected between the two inductive compensation units in series, and the other end of the capacitive compensation unit is grounded; it is characterized in that the method comprises the steps of,
the tuning device comprises a static synchronous compensator STATCOM and/or a static synchronous series compensator SSSC;
the static synchronous compensator STATCOM is connected in parallel to a power transmission line between the two inductive compensation units, and the static synchronous series compensator SSSC is connected in series to the power transmission line at one side of the inductive compensation units;
after the tuning device flexibly tunes the alternating current power transmission system to meet the requirement of the half-wavelength alternating current power transmission system, the alternating current power transmission system is subjected to flexible grid-connected control, power factor compensation, transient overvoltage suppression and steady-state voltage control;
the tuning device comprises two groups of static synchronous series compensators SSSC and a group of static synchronous compensators STATCOM, and the device for flexibly controlling grid connection of an alternating current transmission system comprises the following steps:
the output of the static synchronous series compensator SSSC far away from the grid connection is equivalent to a series inductance/series reactance, the output of the static synchronous series compensator SSSC close to the grid connection is equivalent to a series voltage, and the equivalent voltage value output by the static synchronous series compensator SSSC is controlled so that the voltages of two AC power supplies connected in the grid are identical and the phases are identical;
when the equivalent voltage value output by the static synchronous series compensator SSSC close to the grid connection position reaches the maximum value, the output of the static synchronous series compensator SSSC far away from the grid connection position is adjusted to be equivalent to one series voltage, and the two static synchronous series compensatorSSSCs jointly control the AC power supply to grid connection.
2. A T-hybrid flexible tuning device as claimed in claim 1, wherein the parallel connection of the static synchronous compensator STATCOM to the transmission line comprises:
the static synchronous compensator STATCOM is directly connected in parallel to the power transmission line; or,
the static synchronous compensator STATCOM is connected in parallel to the power transmission line through a transformer, and the capacity output quantity of the static synchronous compensator STATCOM is increased.
3. A T-hybrid flexible tuning device as defined in claim 1, wherein the serial connection of the static synchronous serial compensator SSSC to the transmission line comprises:
the SSSC is directly connected in series with the power transmission line; or,
the SSSC is connected in series with the power transmission line through a transformer, and the inductive output quantity of the SSSC is reduced.
4. A T-hybrid flexible tuning device as defined in claim 1, wherein said tuning device is configured for installation in an ac power transmission system in a manner comprising:
a transmitting end arranged on the alternating current circuit; or,
the receiving end is configured on the alternating current circuit; or,
the power supply device is arranged at a transmitting end and a receiving end of the alternating current circuit; or,
is arranged in the middle section of the alternating current circuit.
5. A T-hybrid flexible tuning device as defined in claim 4, wherein,
when the tuning device is configured at the transmitting end of the alternating current line, flexible tuning control, flexible grid-connected control, power factor compensation, transient overvoltage suppression and steady-state voltage control are carried out on the alternating current transmission system;
when the tuning device is configured at the receiving end of the alternating current line, flexible tuning control, flexible grid-connected control, transient overvoltage suppression and steady-state voltage control are carried out on the alternating current transmission system;
when the tuning device is configured in the middle section of the alternating current line, flexible tuning control, transient overvoltage suppression and steady-state voltage control are performed on the alternating current transmission system.
6. The T-hybrid flexible tuning device of claim 1, wherein the tuning device flexibly tunes the ac power transmission system to meet the requirements of the half-wavelength ac power transmission system, comprising:
equivalent the output of the static synchronous series compensator SSSC to a series inductance/series reactance of the ac transmission system; equivalent the output of the static synchronous compensator STATCOM as a parallel capacitor of the alternating current transmission system;
controlling the static synchronous series compensator SSSC and the inductive compensation unit to jointly output an inductance value required by the half-wavelength alternating current transmission system; and controlling the static synchronous compensator STATCOM and the capacitive compensation unit to jointly output a capacitance value required by the half-wavelength alternating current transmission system.
7. A T-hybrid flexible tuning device as claimed in claim 6, wherein when the line structure, parameters and/or operation mode of the ac power transmission system are changed, the inductance value and capacitance value of the ac power transmission system are made to meet the requirement of the half-wavelength ac power transmission system by adjusting the equivalent inductance value output by the SSSC and the equivalent capacitance value output by the STATCOM.
8. The T-type hybrid flexible tuning device of claim 1, wherein during flexible grid-tie control of the ac power transmission system by the tuning device:
when the grid connection of the alternating current transmission system is completed and the transient operation is transited to the steady operation, the output of the static synchronous series compensator SSSC is equivalent to a series inductance/series reactance, and the static synchronous series compensator SSSC and the inductive compensation unit are controlled to jointly output the inductance value required by the half-wavelength alternating current transmission system;
and in the process of grid connection of the alternating current transmission system and transition from transient operation to steady operation, adjusting an equivalent capacitance value output by the static synchronous compensator STATCOM so as to reduce disturbance at the grid connection.
9. The T-hybrid flexible tuning device of claim 1, wherein the flexible grid-tie of the tuning device comprises:
after the transmitting end alternating current power supply is connected with the alternating current power transmission system, the alternating current power transmission system is connected with the receiving end alternating current power supply in a grid mode; or after the receiving end alternating current power supply is connected into the alternating current power transmission system, the alternating current power transmission system is connected with the transmitting end alternating current power supply in a grid mode.
10. The T-hybrid flexible tuning device of claim 1, wherein the tuning device is mounted at a feed end of an ac line, and wherein power factor compensation of the ac power transmission system comprises:
and (3) equivalent output of the static synchronous compensator STATCOM is equivalent to a parallel capacitor, and the equivalent capacitance value of the output of the static synchronous compensator STATCOM is controlled to compensate reactive power of an alternating current transmission system.
11. A T-hybrid flexible tuning device as defined in claim 1, wherein said tuning device for transient overvoltage suppression of an ac power transmission system comprises:
and (3) equivalent the output of the static synchronous compensator STATCOM to be a parallel reactance, and controlling the static synchronous compensator STATCOM to absorb reactive power of an alternating current transmission system so as to inhibit power frequency overvoltage of a line.
12. A T-hybrid flexible tuning device as defined in claim 1, wherein said tuning device for steady state voltage control of an ac power transmission system comprises:
when the line voltage of the alternating current transmission system is lower, the output of the static synchronous compensator STATCOM is equivalent to a parallel capacitor, and the equivalent capacitance value output by the static synchronous compensator STATCOM is controlled to compensate reactive power of the alternating current transmission system so as to support the line voltage;
when the line voltage of the alternating current transmission system is higher, the output of the static synchronous compensator STATCOM is equivalent to a parallel capacitor with a smaller capacitance value or equivalent to a parallel inductor/reactance, and the equivalent capacitance value or equivalent inductance value output by the static synchronous compensator STATCOM is controlled to compensate the reactive power of the alternating current transmission system so as to support the line voltage.
13. A T-hybrid flexible tuning device as in claim 1, wherein the output of the static synchronous compensator STATCOM comprises a base output and an additional output;
determining the basic output quantity according to the requirement of the static synchronous compensator STATCOM on flexible tuning control of the alternating current transmission system and the parallel connection mode of the static synchronous compensator STATCOM to the alternating current transmission system;
and determining the additional output quantity according to the requirements of the static synchronous compensator STATCOM on flexible grid-connected control, power factor compensation, transient overvoltage suppression and steady-state voltage control of the alternating current transmission system.
14. A T-hybrid flexible tuning device as in claim 1, wherein the output of the static synchronous series compensator SSSC comprises a base output and an additional output;
determining the basic output quantity according to the requirement of the static synchronous series compensator SSSC on flexible tuning control of the alternating current transmission system and the series connection mode of the static synchronous series compensator SSSC connected to the alternating current transmission system;
and carrying out flexible grid-connected control on the alternating current transmission system according to the static synchronous series compensator SSSC to determine the additional output quantity.
15. A T-hybrid flexible tuning device as claimed in claim 1, wherein the tuning device comprises two sets of static synchronous series compensators SSSC, the outputs of which are the same or different.
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| CN106849118A (en) * | 2017-01-16 | 2017-06-13 | 许继集团有限公司 | A kind of half-wave power transmission mixing tuning system based on power electronics commutation technique |
| CN107947140B (en) * | 2017-10-31 | 2022-07-08 | 中国电力科学研究院有限公司 | Control method and device for power fluctuation overvoltage of half-wavelength power transmission line |
| CN112398140B (en) * | 2020-09-23 | 2022-09-02 | 国网浙江省电力有限公司湖州供电公司 | Power equivalent simulation method for static synchronous series compensator of power grid |
| CN113595076A (en) * | 2021-07-31 | 2021-11-02 | 华北电力大学（保定） | Novel long-distance power transmission method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB873250A (en) * | 1957-04-16 | 1961-07-19 | Tesla Np | Multi-waveband line trap for carrier systems operating on high voltage transmission lines |
| CN101183791A (en) * | 2007-12-19 | 2008-05-21 | 湖南大学 | Static reactive compensator and active power filter combined operation system and control method thereof |
| CN201430444Y (en) * | 2009-06-23 | 2010-03-24 | 华研国电(北京)科技发展有限公司 | Compensation device |
| CN104578069A (en) * | 2014-12-05 | 2015-04-29 | 国家电网公司 | Flexible half-wave power transmission system based on power electronic commutation technology and tuning method of system |
| CN204464995U (en) * | 2015-01-09 | 2015-07-08 | 上海英同电气有限公司 | A kind of harmonic compensation circuit |
| CN205724902U (en) * | 2016-06-23 | 2016-11-23 | 全球能源互联网研究院 | A kind of flexible tuner of T-shaped mixing |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9270008B2 (en) * | 2011-01-28 | 2016-02-23 | The University Of Electro-Communications | Transmission line resonator, bandpass filter using transmission line resonator, multiplexer, balanced-to-unbalanced transformer, power divider, unbalanced-to-balanced transformer, frequency mixer, and balance-type filter |
-
2016
- 2016-06-23 CN CN201610462950.5A patent/CN106130021B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB873250A (en) * | 1957-04-16 | 1961-07-19 | Tesla Np | Multi-waveband line trap for carrier systems operating on high voltage transmission lines |
| CN101183791A (en) * | 2007-12-19 | 2008-05-21 | 湖南大学 | Static reactive compensator and active power filter combined operation system and control method thereof |
| CN201430444Y (en) * | 2009-06-23 | 2010-03-24 | 华研国电(北京)科技发展有限公司 | Compensation device |
| CN104578069A (en) * | 2014-12-05 | 2015-04-29 | 国家电网公司 | Flexible half-wave power transmission system based on power electronic commutation technology and tuning method of system |
| CN204464995U (en) * | 2015-01-09 | 2015-07-08 | 上海英同电气有限公司 | A kind of harmonic compensation circuit |
| CN205724902U (en) * | 2016-06-23 | 2016-11-23 | 全球能源互联网研究院 | A kind of flexible tuner of T-shaped mixing |
Non-Patent Citations (2)
| Title |
|---|
| 半波长交流输电技术的研究现状与展望;王冠等;电力系统自动化;第34卷(第16期);14-15 * |
| 半波长输电线路故障暂态过电压特性研究;师伟;孙秋芹;李庆民;王冠;吕鑫昌;李庆余;;电网技术;36(2);43-37 * |
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