Power flow control subsystems having multiple configurations

Abstract

A power flow control subsystem having multiple configurations is described. The subsystem is configurable in three ways: a transportable configuration, a deployable configuration, and a transmission line configuration. The transportable configuration includes a set of impedance injection modules and at least one bypass module that are carried on a wheeled vehicle such as a trailer. The deployable configuration is an assembly of the set of impedance injection modules and at least one bypass module that are operable to perform power flow operations. The transmission line configuration includes a connection of the deployable configuration to a phase of a high voltage transmission line for performing power flow control. The deployable configuration can be an open frame or a closed frame. The deployable configuration can be mounted on one or more wheeled vehicles in a mobile subsystem, or semi-permanently mounted at a ground site.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 799,630, filed January 31, 2019, the disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to a power flow control subsystem, and more particularly to a power flow control subsystem having a transportable configuration, a deployable configuration, and a transmission line configuration. Background Technology

[0004] Power flow control systems are complex sets of modules and components that need to be delivered, configured, and tested at the installation site.

[0005] To reduce installation time and make the installation process more efficient, there is a need in the field for multiple configurable subsystems optimized for their transportation, deployment, and power line implementation. Attached Figure Description

[0006] Figure 1 This is a perspective view of a wheeled trailer that transports the power flow control equipment to the installation site.

[0007] Figure 2 It is a perspective view of a collection of standardized power flow control subsystems configured for deployment when mounted on wheeled vehicles.

[0008] Figure 3 This is a cross-sectional view of a power flow control system, which includes a power flow control subsystem in its transmission line configuration.

[0009] Figure 4 This is a front cross-sectional view of a power flow control subsystem installed on a semi-permanent foundation in an open-frame configuration.

[0010] Figure 5 This is a perspective view of the closed-frame configuration of the power flow control subsystem.

[0011] Figure 6 It is a perspective view of an insulating post used to mount multiple power flow control subsystems on a semi-permanent foundation.

[0012] Figure 7 It is a perspective view of a pair of wheeled trailers carrying power flow control equipment.

[0013] Figure 8 This is a perspective view of the power flow control subsystem deployed on the main trailer, with accompanying passenger trailers nearby.

[0014] Figure 9is a flowchart of an exemplary method for deploying a power flow control subsystem on a wheeled vehicle, including connecting to and operating in a high voltage transmission line.

[0015] Figure 10 is a flowchart of an exemplary method for deploying a power flow control subsystem at a ground mounted site, including connecting to and operating in a high voltage transmission line. DETAILED DESCRIPTION

[0016] A power flow control subsystem is described having multiple configurations. The subsystem is configurable in three ways: a transportable configuration, a deployable configuration, and a transmission line configuration. The transportable configuration includes a set of impedance injection modules and at least one bypass module, which are carried on a wheeled vehicle such as a trailer. The deployable configuration is an assembly of the set of impedance injection modules and at least one bypass module, which is operable to perform power flow operations. The transmission line configuration includes a connection of the deployable configuration to a phase of a high voltage transmission line for performing power flow control. The deployable configuration can be an open frame or a closed frame. The deployable configuration can be mounted on one or more wheeled vehicles in a mobile subsystem, or semi-permanently at a ground site.

[0017] During normal operation, each impedance injection module is connected in series to the power transmission line. By injecting a synthesized waveform onto the line, the impedance of the line can be adjusted to provide more efficient routing of current among the available transmission lines in a power distribution system, thus enabling power flow control. The synthesized waveform can be used to inject a capacitive or inductive impedance onto the line that is effective for power flow control, without substantially contributing to losses in the line.

[0018] Each impedance injection module includes voltage and current sensors that provide early warning of a fault condition. Typically, the fault condition is detected by detecting an imbalance of current from one phase to another. When this occurs, the bypass switch connects in a bypass mode to bypass the associated impedance injection module and carry the fault current. This condition of the power flow control system can be described as a "monitoring mode."

[0019] It can be convenient to define an exemplary power flow control subsystem that includes five impedance injection modules and one bypass switch. This exemplary subsystem can be transported and conveniently configured as a deployable subsystem. For example, each subsystem can be used to inject 5 megavar (MVAR) of reactive power, and multiple such power flow control subsystems can be connected in series to achieve higher levels of impedance injection.

[0020] Figure 1A wheeled vehicle 10 carrier apparatus for installing a power flow control system on a high voltage transmission line is depicted. The wheels 11 of the wheeled vehicle are shown. The wheeled vehicle 10 can be a trailer or any other wheeled vehicle capable of carrying the apparatus. A bypass switch module 12 and an impedance injection module 13 are shown. In one embodiment, the impedance injection module 13 can be a transformerless static synchronous series compensator (TSSSC). An insulating column 14 is also shown. A collection of power flow control apparatus 15 is shown, including an exemplary set of 5 impedance injection modules and one bypass switch module, configured as a transportable configuration of the power flow control subsystem of the present disclosure. The power flow control subsystem can have a variety of configurations to be described herein. It will be further described that the power flow control subsystem can include a set of insulating columns 14, in the exemplary configuration containing 4 columns.

[0021] Figure 2 A wheeled vehicle 20 is shown, to which an exemplary set of three power flow control subsystems are attached. Subsystem 21 is in its deployable configuration, which is shown mounted on a set of insulating columns 14. The deployable configuration is operable to perform power flow operations when, for example, connected to a transmission line as appropriate. The separation distance 22 (referred to as "S" in Figure 2

[0022] Figure 3 A transmission line configuration of the power flow control system 30 of the present disclosure is illustrated. A wheeled vehicle 10 is shown, on which a set of power flow control subsystems are carried. Each subsystem is in its deployable configuration. A jumper cable connection 31 is shown, carried by a pole 32, in which a connection is made from the subsystem to a phase 33 of a high voltage transmission line, the connection to the phase 33 being connected to a transmission line tower 34 by an insulator (not shown). As shown, a shielded cable 35 can also be employed. An in-line transmission isolator 36 is also shown. It can be clearly understood that this exemplary configuration of the system 30 can be adapted to use power flow control subsystems connected to semi-permanent ground pads, rather than to a wheeled vehicle.

[0023] Figure 4 ​A power flow control subsystem 40 of the present disclosure is shown in an open frame configuration, including a corona ring 41. An exemplary set of six similarly sized modules 42 are shown, each equipped with lifting attachments 43 suitable for deployment, for example, using a crane. Any lifting device can be used, including hydraulic lifts and screw jack devices. At the bottom of the power flow control subsystem 40, access tubes (not shown) for lifting with a forklift can be provided. Straps 44 between the modules 42 are also shown; they are electrical bus bars that transfer voltage and current. The open frame configuration is carried on insulating posts 45, with interface assemblies 46 shown for connection to semi-permanent foundations such as 47. The semi-permanent foundations 47 can be implemented, for example, as concrete pedestals; other types of foundations and interface assemblies can also be used. The open frame configuration of the subsystem 40 has the advantage of ease of maintenance and ready access to the interior modules.

[0024] Figure 5 A power flow control subsystem 50 of the present disclosure is depicted in a closed frame configuration, with a series of doors 51 open to access the interior modules (such as bypass switch modules and one or more impedance injection modules) in its deployed configuration. In comparison to the open frame configuration of Figure 4 The closed frame configuration 50 can be more compact, smaller in size, lighter in weight, and less prone to damage during transport and installation than the open frame configuration. As shown, a row of cooling fans 52 can be provided. A carrying handle 53 is shown along with a corona ring 54. The corona ring 54 helps reduce arcing to adjacent equipment and ground. Connectors 55 (e.g., National Electrical Manufacturers Association (NEMA) connectors) are shown, providing a standard method of connection to phases of a high voltage transmission line supported, for example, by a tower. The connection can also be made in a substation or any other suitable location, without involving a tower.

[0025] Figure 6 A set of ground pedestals 60 for power flow control systems at an installation site are depicted. The installation site includes semi-permanent foundations 61, provided, for example, for semi-permanent installation of power flow control subsystems. The installation site can include a sufficient number of isolation / insulation posts 62 for installation of several power flow control subsystems. The posts 62 can include a steel portion for lifting energized elements to a minimum height above the ground, plus an insulating portion at the top end of each post.

[0026] An exemplary power flow control subsystem includes five impedance injection modules and one bypass switch module in the power flow control subsystem, and is operable to perform power flow control of at least 5 MVAR (Megavolt-Ampere Reactive) (e.g., up to 15 MVAR).

[0027] Figure 7A pair of companion wheeled vehicles 71 and 72 are illustrated for transporting a power flow control system. The wheeled vehicles can be transported over highways without additional motive power; they can also be carried as cargo by rail, by ship, or by air, and driven over highways near their destination, as examples. In Figure 7 In the middle, wheeled vehicle 72 can be referred to as an "object trailer" or "object vehicle"; it carries power flow control equipment, such as impedance injection modules 74 and insulating posts 14, and can not be well suited to a deployed configuration of the power flow control subsystem. Wheeled vehicle 71 can be referred to as a "subject trailer" or "subject vehicle" because the subsystem can be installed in its deployed configuration, ready for operation in a power flow control system.

[0028] Figure 8 Subject trailer 71b is shown with three power flow control subsystems 21 installed in their deployed configuration, ready for power flow operation. Object trailer 72b is empty. Subject trailer 71b is shown with foldable outrigger beams 81 to stabilize the mobile installation. Load levelers (not shown) can also be provided.

[0029] Figure 9 A flowchart of a method 90 is depicted, which is an exemplary method for installing and operating a power flow control system of the present disclosure. Method 90 includes the following steps:

[0030] At step 91, a power flow control subsystem is defined that includes a plurality of impedance injection modules and at least one bypass module,

[0031] At step 92, the plurality of power flow control subsystems are transported to an installation site on at least one vehicle,

[0032] At step 93, each of the plurality of power flow control subsystems is assembled into a deployable configuration that is operable to perform power flow operations when carried by one of the at least one vehicle,

[0033] At step 94, each deployable configuration is attached to a phase of a high voltage transmission line, and,

[0034] At step 95, each deployable configuration is operated to implement power flow control.

[0035] Figure 10 A flowchart of an alternative exemplary method 100 is depicted, which is for installing and operating a power flow control system of the present disclosure. Method 100 includes the following steps:

[0036] At step 101, a power flow control subsystem is defined that includes a plurality of impedance injection modules and at least one bypass module,

[0037] At step 102, a plurality of power flow control subsystems are transported to an installation site on at least one vehicle,

[0038] At step 103, each of the plurality of power flow control subsystems is assembled into a deployable configuration operable to perform power flow operations,

[0039] At step 104, each deployable configuration is installed on a semi-permanent (or permanent) foundation,

[0040] At step 105, each deployable configuration is attached to a phase of a high voltage transmission line, and,

[0041] At step 106, each deployable configuration is operated to implement power flow control.

[0042] Variations of methods 90 and 100 using various embodiments of power flow control systems and subsystems are readily designed in accordance with the teachings herein.

Claims

1. A subsystem of a power flow control system, the subsystem comprising: a plurality of impedance injection modules, wherein each of the plurality of impedance injection modules is a transformerless static synchronous series compensator (TSSSC); and at least one bypass module; wherein the subsystem is configurable in three configurations: a transportable configuration, wherein the plurality of transformerless static synchronous series compensators (TSSSCs) and the at least one bypass module are attached to and carried by a wheeled vehicle; a deployable configuration, wherein the plurality of transformerless static synchronous series compensators (TSSSCs) and the at least one bypass module are mechanically and electrically connected to form a single unit, the single unit being operable to perform power flow operations; and a transmission line configuration, wherein the deployable configuration is connected to a high voltage transmission line for performing power flow control operations.

2. The subsystem of claim 1, wherein: the deployable configuration comprises an open frame, and the plurality of impedance injection modules and the at least one bypass module are attached to the open frame.

3. The subsystem of claim 1, wherein, the deployable configuration comprises a closed frame, and the plurality of impedance injection modules and the at least one bypass module are contained within the closed frame.

4. The subsystem of claim 1, wherein, power flow control operations are performable when the deployable configuration is carried by the wheeled vehicle.

5. The subsystem of claim 1, wherein, power flow control operations are performable when the deployable configuration is attached to a semi-permanent foundation.

6. The subsystem of claim 1, wherein: the plurality of impedance injection modules comprises five impedance injection modules; the at least one bypass module comprises one bypass module; and the subsystem is operable to perform power flow control of at least 5 megavolt-ampere reactive (MVAR).

7. A method for installing and operating a power flow control system, the method comprising: defining a power flow control subsystem comprising a plurality of impedance injection modules and at least one bypass module, wherein each of the plurality of impedance injection modules is a transformerless static synchronous series compensator (TSSSC); transporting a plurality of such power flow control subsystems on at least one vehicle to an installation site; assembling each of the plurality of such power flow control subsystems into a deployable configuration, the deployable configuration being operable to perform power flow operations when carried by the at least one vehicle; attaching each deployable configuration to a phase of a high voltage transmission line; and, 8. The method of claim 7, wherein, operating each deployable configuration to implement power flow control. the at least one vehicle comprises: a host vehicle on which impedance injection modules and bypass modules are transported and on which a plurality of such deployable configurations are deployable; and 9. The method of claim 7, wherein, a guest vehicle, the guest vehicle being used to transport additional impedance injection modules, additional bypass modules, and additional installation equipment.

10. The method of claim 7, wherein, the deployable configuration comprises an open frame, and the plurality of impedance injection modules and the at least one bypass module are attached to the open frame. the deployable configuration comprises a closed frame, and the plurality of impedance injection modules and the at least one bypass module are contained within the closed frame.

11. The method of claim 7, further comprising: performing power flow control operations when the deployable configuration is carried by the at least one vehicle.

12. The method of claim 7, further comprising: performing power flow control operations when the deployable configuration is attached to the semi-permanent foundation.

13. The method of claim 7, wherein: the plurality of impedance injection modules comprises five impedance injection modules; the at least one bypass module comprises one bypass module; and the method further comprises performing power flow control of at least 5 megavolt-ampere reactive (MVAR).

14. A method for installing and operating a power flow control system, the method comprising: defining a power flow control subsystem comprising a plurality of impedance injection modules and at least one bypass module, wherein each of the plurality of impedance injection modules is a transformerless static synchronous series compensator (TSSSC); transporting a plurality of such power flow control subsystems on at least one vehicle to an installation site; assembling each of the plurality of such power flow control subsystems into a deployable configuration, the deployable configuration being operable to perform power flow operations; installing each deployable configuration on a semi-permanent foundation; attaching each deployable configuration to a phase of a high voltage transmission line; and, operating each deployable configuration to achieve power flow control.

15. The method of claim 14, wherein, the at least one vehicle comprises: a host vehicle on which impedance injection modules and bypass modules are transported and on which a plurality of such deployable configurations can be deployed; and a guest vehicle for transporting additional impedance injection modules, additional bypass modules, and additional installation equipment.

16. The method of claim 14, wherein, the deployable configuration comprises an open frame, and the plurality of impedance injection modules and the at least one bypass module are attached to the open frame.

17. The method of claim 14, wherein, the deployable configuration comprises a closed frame, and the plurality of impedance injection modules and the at least one bypass module are contained within the closed frame.

18. The method of claim 14, wherein: the plurality of impedance injection modules comprises five impedance injection modules; the at least one bypass module comprises one bypass module; and the method further comprises operating the power flow control subsystem to perform power flow control of at least 5 megavolt-ampere reactive (MVAR).

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