Extensible and movable AC / DC transformer station

Abstract

A modular scalable AC / DC substation (102A) converts an AC voltage to a DC voltage to drive high voltage, high current loads, such as heavy duty work machines. A substation (102A) sized to be accommodated within a standard high cube ISO container, the substation comprising a main transformer (214) attached at the center of a rectangular base (104), a pair of controlled rectifiers (230, 232) located on the base (104) downstream of the main transformer (214) arranged in alignment parallel to a transverse axis of the base (104), and is substantially symmetrical about the longitudinal axis of the base (104). The arrangement of these components on the base (104) along with low pass filters (234) and switching devices (216, 236, 238) achieves a high power density of the substation (102), provides a balanced mass to ensure stability during shipping and seating, and helps protect personnel from unexpected arcing.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a scalable, mobile AC / DC substation for supplying high voltage DC power. More particularly, the present disclosure relates to a modular substation for AC / DC power conversion having transformers and controlled rectifiers configured to achieve high power density within the footprint of a standard shipping container. BACKGROUND

[0002] Heavy duty work machines, such as earthmoving vehicles or haul trucks, require significant power to perform their functions. These machines can themselves be of considerable weight, and their loads require significant power to move. Diesel engines typically provide this power. As the work machine moves, electric power is delivered from overhead wires on the transport route to a pantograph on the work machine as a supplement to the diesel power. However, overhead wires cannot reliably provide enough power to power heavy duty work machines over long distances of travel, nor can they simultaneously charge the backup batteries of electrically powered machines. To completely replace diesel power, a power rail can provide high voltage direct current (DC) power to a sliding contact on the machine as it moves along the transport route.

[0003] Equipment that delivers DC power to a conductor, such as a power rail, for heavy duty work machines must typically be mobile. For example, mine sites are often located in remote, rugged environments that have access to alternating current (AC) voltage only through high voltage distribution lines. Therefore, equipment for converting high voltage AC power to low voltage DC power that work machines can use must be transported to the work site to form a power plant or substation. As the site is mined, logged, or otherwise worked, the substation can need to be relocated. Substations designed for a particular site and involving high voltage, high current cabling can require complex commissioning and decommissioning when relocation is required.

[0004] Substations also need to prevent accidental arcing between high voltage equipment and personnel. Modular substations for remote locations often contain electrical equipment, such as switchgear and transformers, that are aligned in a planar layout along the back wall of a rectangular structure. A corridor extends along the front wall of the substation from which personnel can access the equipment and potentially be exposed to arcing during equipment operation. This arrangement also concentrates heavy electrical equipment in one portion of the substation, resulting in an unstable structure that is difficult to transport.

[0005] U.S. Patent No. 8,872,366 (“the ‘366 patent”) describes an arrangement for a mobile containerized substation for deployment in remote areas. The ‘366 patent describes a modular and scalable power facility for generating and distributing power at disaster sites. The substation module within the power facility contains two transformers mounted at opposite ends of the substation, with gas insulated cabinets disposed between the transformers along the back wall of the substation. Personnel can access the gas insulated cabinets from a control room located in the middle portion of the substation. In addition to this, the substation in the ‘366 patent is geared towards AC power distribution, cannot accommodate the equipment required to generate DC power, and its equipment poses an electrical arc discharge risk to personnel in the control room. Thus, the substation in the ‘366 patent is not suitable as a mobile substation for transmitting high voltage DC power.

[0006] Examples of the present disclosure are directed to overcoming the deficiencies of such systems. SUMMARY

[0007] In one aspect of this disclosure, a system for transmitting electrical energy in the form of DC voltage includes: a modular substation configured to receive AC input and provide DC voltage output; and a conductive rail electrically coupled to the modular substation and configured to transmit the DC voltage output to a load connected to the conductive rail. The modular substation includes a base having a generally planar rectangular shape, the top surface of which extends longitudinally from a first end to a second end and laterally from a front side to a rear side. A longitudinal axis extends along the top surface and is generally centered between the front and rear sides; and a transverse axis extends along the top surface and is generally centered between the first and second ends. The substation includes an AC voltage switching device configured to receive the AC voltage input from an external power source; and an auxiliary transformer configured to be electrically coupled to the AC voltage switching device. The auxiliary transformer and the AC voltage switching device are aligned on the top surface of the base, generally parallel to the transverse axis, and located between the transverse axis and the first end. The substation also includes a main transformer located at the intersection of the longitudinal and transverse axes, having a primary winding and a secondary winding electrically coupled to the AC voltage switching device. A pair of controlled rectifiers are electrically coupled to at least the secondary winding of the main transformer and configured to generate the DC voltage output. The pair of controlled rectifiers are aligned on the base, generally parallel to the transverse axis, and located between the main transformer and the second end. One or more low-pass filters are electrically coupled to the pair of controlled rectifiers and positioned generally parallel to the transverse axis, and symmetrical about the longitudinal axis between the pair of controlled rectifiers and the second end. The substation also includes a DC voltage switching device electrically coupled to the one or more low-pass filters and configured to receive the DC voltage output from the one or more low-pass filters. The DC voltage switching device is positioned near the second end of the base, generally parallel to the transverse axis, and symmetrical about the longitudinal axis.

[0008] In another aspect of this disclosure, a mobile substation includes a rectangular platform having a top surface whose geometric center is located between an upstream end and a downstream end, and between a first side and a second side. A longitudinal axis passes through the geometric center and is generally parallel to the first and second sides along the top surface, and a transverse axis passes through the geometric center and is generally parallel to the upstream and downstream ends along the top surface. The substation includes a main high-voltage transformer attached to the top surface, symmetrical about the longitudinal axis and about the transverse axis; and an AC voltage switching device attached to the top surface, upstream of the main high-voltage transformer and generally parallel to the transverse axis. A pair of controlled rectifiers are attached to the top surface, downstream of the main high-voltage transformer, and aligned together, generally parallel to the transverse axis. One or more low-pass filters are attached to the top surface, downstream of the pair of controlled rectifiers, and symmetrical about the longitudinal axis. The substation also includes a DC voltage switching device attached to the top surface, near the downstream end, generally parallel to the transverse axis, and symmetrical about the longitudinal axis.

[0009] In another aspect of this disclosure, a method of assembling a mobile substation includes: providing a rectangular platform, the geometric center of which is located between an upstream end and a downstream end, and between a first side and a second side; and assembling electrical equipment for converting AC electricity to lower voltage DC electricity onto the rectangular platform. A longitudinal axis passes through the geometric center and is generally parallel to the first and second sides, and a transverse axis passes through the geometric center and is generally parallel to the upstream and downstream ends. The method includes, in any order: attaching a main high-voltage transformer symmetrical about the longitudinal axis and about the transverse axis; attaching an AC voltage switching device upstream of the main high-voltage transformer and generally parallel to the transverse axis; attaching a pair of controlled rectifiers downstream of the main high-voltage transformer; attaching one or more low-pass filters downstream of the pair of controlled rectifiers and symmetrical about the longitudinal axis; and attaching a DC voltage switching device near the downstream end, generally parallel to the transverse axis and symmetrical about the longitudinal axis. Attached Figure Description

[0010] Detailed description is provided with reference to the accompanying drawings. In the drawings, the leftmost numeral of the reference numeral indicates the first figure in which the reference numeral appears. Identical reference numerals indicate similar or identical items.

[0011] Figure 1 This is an isometric view of a general system for transmitting electrical energy in the form of DC voltage, according to an example of this disclosure.

[0012] Figure 2It is based on the example of this disclosure. Figure 1 A top view of a mobile substation.

[0013] Figure 3 It is based on the example of this disclosure. Figure 2 A schematic block diagram of an alternative plan view for a mobile substation.

[0014] Figure 4 It is based on the example of this disclosure. Figure 1 Front view of the mobile substation.

[0015] Figure 5 It is based on the example of this disclosure. Figure 1 Right-side view of the mobile substation in the image.

[0016] Figure 6 This is a flowchart depicting a method for assembling a mobile substation according to an example of this disclosure. Detailed Implementation

[0017] Based on the principles of this disclosure, a modular, scalable AC / DC substation transforms AC voltage into DC voltage to drive high-voltage, high-current loads such as heavy-duty machinery. In some examples, the heavy-duty machinery may be large electric transport trucks configured to move payloads within a work site, such as an open-pit mine. The substation is designed to be housed in a container conforming to standard ISO shipping containers and includes a rectangular platform or base, four walls, and an optional roof. On the rectangular platform, the main transformer is attached approximately at the geometric center where the longitudinal and transverse axes intersect. AC switching equipment that receives and switches AC voltage from an external power source is located on the platform, upstream of the main transformer, while a pair of controlled rectifiers are located downstream of the main transformer. The rectifiers are aligned parallel to the transverse axis and are approximately symmetrical about the longitudinal axis. A low-pass filter and DC switching equipment are also attached to the platform, downstream of the rectifiers, and positioned symmetrically about the longitudinal axis. The arrangement of these components on the base, particularly when receiving medium-voltage AC input in the range of 11kVAC to 33kVAC and producing DC output in the range of + / -1500VDC, enables high power density in the substation, provides balanced mass to ensure stability of the substation during transport and installation, and helps protect personnel from accidental arc discharge. Several examples of implementing the principles of this disclosure are described below.

[0018] Figure 1 This is an isometric view of a general-purpose system 100 for transmitting electrical energy in the form of DC voltage within an XYZ coordinate system, as an example suitable for implementing the principles discussed in this disclosure. Figure 1As illustrated, system 100 typically includes one or more substations 102, such as substation 102A and substation 102B, and conductive paths such as conductive rails 140. The substations receive AC voltage from an external power source (not shown), such as AC distribution, and convert and regulate that AC voltage to DC voltage. The converted DC voltage is then distributed along conductive rails 140 for use by loads (not shown), such as heavy-duty machinery.

[0019] System 100 can be located in any environment requiring DC distribution voltage, particularly where substation 102 (and possibly conductor rail 140) may require periodic commissioning, dismantling, and relocation. Substation 102 is essentially self-contained and suitable for environments where electrical equipment and related resources may be scarce. In some examples, system 100 is located in a remote mine or logging site, and the load is heavy-duty machinery powered by the DC voltage on conductor rail 140 to transport the load. In other implementations, the heavy-duty machinery does not need to transport a load and can be any machinery associated with a variety of industrial applications, including but not limited to mining, agriculture, forestry, construction, and other industrial applications.

[0020] like Figure 1 As illustrated, each of the substations 102 is rectangular in shape, but depending on the implementation, the substation 102 may also adopt other forms. Referring to substation 102A, its external structure includes a base 104, a front wall 106, a rear wall 108, a first end wall 110, a second end wall 112, and a top cover 114. One or more doors exist within the walls of substation 102A leading to the interior of the structure, such as end doors 116 within the first end wall 110. Due to the heat generated by the electrical equipment within substation 102A as described below, several air conditioning units 118 cool the interior; these air conditioning units may form part of one or more walls, as... Figure 1 The rear wall 108. Otherwise, panel 122 forms an external structure within the wall to shield the interior and prevent access. In some examples, substation 102 is lifted off the ground by a support structure that... Figure 1 The block or pier 124 is shown in the diagram. The pier 124 can be of any shape or composition and is used to hold the substation 102 above the ground. In some examples, the pier 124 is about 1.0 meter high and helps to prevent access to the substation 102, as will be discussed further below.

[0021] In some examples, substations 102A and 102B are modular, mobile structures with largely the same structure and composition. For ease of transport, the external dimensions of each substation 102 after assembly are intended to be sufficient to fit within a standard-sized container, i.e., conforming to the internal dimensions of a container. In one example, according to ISO 668:2020, the 1AAA series standard “high cubic” intermodal container is 40 feet (12.19 meters) long, 8 feet (2.44 meters) wide, and 9.6 feet (2.5 meters) high. Therefore, in one example, each substation 102 can be loaded into a container conforming to ISO 668:2020, transported to a location on the work site, and unloaded, requiring minimal additional parts or setup activities to configure and operate. Similarly, as operations progress, substations 102 can be dismantled from that location and relocated intact to a new destination, such as another location within the site. Based on the size and electrical performance of substation 102 and the logistical considerations for moving substation 102 between different locations, containers of other sizes and standards can also be used to transport the equipment.

[0022] In addition to its modular design, the substation 102 within system 100 is also scalable. Therefore, the power capacity delivered to conductor rail 140 can be altered by electrically connecting or disconnecting substations 102A and 102B. In some examples, each substation in substation 102 receives an AC voltage input from an external power source (such as an AC medium-voltage distribution line) at a frequency of 50Hz or 60Hz, typically within the 11.0kV to 33kV three-phase AC voltage range. Each substation in substation 102 can then transform and convert the AC voltage input into a DC voltage output, up to + / -1500VDC, with a nominal value of + / -1400VDC and a power of approximately 7.5MW to 10MW. It should be noted that the AC voltage input range and / or DC voltage output range are merely examples, and other suitable values ​​for the AC voltage input and / or DC voltage output are contemplated in this disclosure.

[0023] If required by the implementation method, multiple substations 102 can be modularly combined in the field via connection 126 to generate a higher level of output power. Combining via connection 126 may involve coupling the DC switching equipment described below at the output of each substation. For example, substations 102A and 102B can be combined via connection 126 as follows: Figure 1The circuit is electrically paired to provide 15MW (2 x 7.5MW) of power at + / - 1500VDC to drive the load on conductor rail 140. Similarly, two additional substations 102 (not shown) can be combined with substations 102A and 102B to generate 30MW (4 x 7.5MW) of DC power. It should be understood that the described voltages and powers are merely exemplary, as various levels of AC voltage and combinations of AC and DC voltages can be used depending on the specific configuration. Furthermore, other variations can be used to implement this modular design and will be known to those skilled in the art.

[0024] Back Figure 1 The diagram illustrates a conductive rail 140 placed on the ground to supply DC power from substation 102 to loads (not shown), such as heavy-duty machinery. Figure 1 In general, the conductive rail 140 is installed as part of a track support module 142, which is an example of a support assembly used to securely position the conductive rail 140 along one side of a transport route. When implemented for an entire transport route, such as within a mine, the track support module 142 will be a component within a series or sequence of structures providing mechanical stability to the conductive rail 140 along the path used for conducting electricity. The track support module 142 typically includes a barrier 144 as a base for retaining a support rod 146 that holds the conductive rail 140 at an elevated position and provides insulation. In one example, the barrier 144 is primarily made of concrete, with reinforcing steel bars (not shown) embedded within the concrete to enhance the robustness of the barrier 144, although other designs are also feasible. Figure 1 Figure 148 illustrates the relative height of the conductive rail 140, which is achieved by support rod 146. By raising the conductive rail 140 above the typical reach of figure 148, support rod 146 helps improve the safety of power transmission from substation 102 within system 100.

[0025] In some examples, the conductive rail 140 has two or more conductors, each providing voltage and current at a different electrode. In an implementation where the conductive rail 140 includes three conductors, one conductor provides a positive DC voltage, a second conductor provides a negative DC voltage, and a third conductor provides 0 volts relative to the other two conductors. In some examples, two energized conductors within the conductive rail 140 provide +1500VDC and -1500VDC received from the substation 102. For example, heavy-duty machinery can obtain DC power to generate traction via a contactor configured to maintain electrical connection with the conductive rail 140 as it slides along its surface.

[0026] Figure 2 to Figure 5The overall layout of substation 102 within system 100 is illustrated for transmitting electrical energy to conductor rail 140 in the form of DC voltage. Figure 2 Different perspectives and components of the representative substation 102A are illustrated. Figure 2 This is a top view of substation 102A, showing a plan view of a construction scheme conforming to the principles of this disclosure. Therefore, Figure 2 The arrangement of electrical components located on base 104 within substation 102A is shown. This base may also be referred to as a floor, platform, support, or other planar horizontal surface at the bottom of the substation.

[0027] The base 104 is roughly rectangular in shape, with two parallel sides and two parallel ends, the length of which is shorter than the length of the parallel sides. That is, in Figure 1 On the left side, the base 104 has a first end or upstream end 202. As will be discussed below, the components are generally arranged from left to right on the base 104 in the direction of the current flowing through the substation 102A, such that the left end of the base 104 may be referred to as the upstream end 202. The upstream end 202 is directly or indirectly connected to the first end wall 110 ( Figure 2 Opposite to the upstream end 202, the downstream end 204 of the base 104 is directly or indirectly connected to the second end wall 112. These lateral ends are connected to the two longer sides or longitudinal sides of the top and bottom of the top view 200. Specifically, the front side 206 and the rear side 208 are directly or indirectly connected to the front wall 106 and the rear wall 108, respectively. For orientation purposes, Figure 2 The diagram shows a transverse axis A–A extending along the top surface 210 of the base 104, equidistantly located between the upstream end 202 and the downstream end 204; while a longitudinal axis B–B extends along the top surface 210, equidistantly located between the front side 206 and the rear side 208. The transverse axis A–A and the longitudinal axis B–B intersect at a point that substantially corresponds to the geometric center 212 of the base 104.

[0028] like Figure 2 As depicted, the main transformer 214 is located at the center 212 of the base 104. In some examples, the main transformer 214 is positioned symmetrically about the longitudinal axis and about the transverse axis. In other words, in some examples, the main transformer 214 is equidistantly located between the upstream end 202 and the downstream end 204, and equidistantly located between the front side 206 and the rear side 208. In some examples, the main transformer 214 may include more than one transformer that operates electrically together and is positioned together as a common unit around the center 212. The main transformer 214 may be considerably heavy compared to other components on the base 104. Positioning the main transformer 214 at or near the center 212 helps balance the mass of the substation 102A, facilitating the transport and installation of the substation, as will be discussed in detail below.

[0029] exist Figure 2 In the example, the main transformer 214 is a step-down transformer with a primary winding and a secondary winding. The primary winding is used to receive three-phase AC voltages ranging from 11kV to 33kV at various primary taps, and the secondary winding is used to generate corresponding three-phase AC voltages at various secondary taps. In one example, the main transformer 214 is configured to generate 1.2kVAC at each secondary winding when the rated continuous power is 6.5MVA. This main transformer is typically capable of operating at a power capacity of approximately 7.5MW to 10MW. Alternatively, the main transformer 214 can be a resin-cast dry-type three-phase transformer weighing 8 to 10 metric tons. The dimensions of the main transformer 214 are generally approximately 2 to 3 meters in length, 1 to 2 meters in width, and 2 to 3 meters in height. To prevent the main transformer 214 from moving during the displacement of substation 102A (such as the transportation, commissioning or dismantling of the substation), the main transformer 214 may be fixed to the top surface 210 of the base 104 by bolts or other attachment devices.

[0030] Upstream of main transformer 214, i.e. Figure 2 On the left side of the substation 102A, there is an AC switchgear 216 and an auxiliary transformer 218. The AC switchgear 216 includes a series of components configured to connect, disconnect, and otherwise switch lines receiving AC input voltage from an external power source (such as AC distribution lines near substation 102A). The AC switchgear 216 provides input-side protection for the system and personnel, for example, detecting ground faults detected on the AC voltage side, responding to potential transformer overheating conditions, and performing other detections and de-energizing of components at the AC input section of the substation. Therefore, the AC switchgear 216 may include multiple safety and relay mechanisms, such as three-phase disconnect switches and / or one or more three-phase AC circuit breakers, electrically located between the AC voltage source and the main transformer 214. When substation 102A is in operation, the AC switchgear 216 provides a closed electrical path for supplying AC voltage from the external power source to the primary winding of the main transformer 214.

[0031] Auxiliary transformer 218 is a three-phase AC transformer, also electrically coupled to AC switchgear 216, and configured to supply power to equipment and installations within the substation after converting the AC input voltage to a DC output voltage. For example, auxiliary transformer 218 can power lighting fixtures, control systems, circulating fans, and other electrical components within the substation. In some examples, auxiliary transformer 218 is a 100kVA three-phase AC transformer. Figure 2As illustrated, the AC switchgear 216 and auxiliary transformer 218 are located on the top surface 210, generally parallel to the transverse axis A–A, and between the transverse axis A–A and the upstream end 202. Although the AC switchgear 216 may be much wider than the auxiliary transformer 218 in the transverse direction (i.e., along the transverse axis A–A), in some examples, the AC switchgear 216 and auxiliary transformer 218 may be arranged as a pair, equidistantly positioned between the front side 206 and the rear side 208. To prevent the AC switchgear 216 and auxiliary transformer 218 from moving during displacement of the substation 102A (such as the transport, commissioning, or dismantling of the substation), bolts or other attachments may be used to secure the AC switchgear 216 and auxiliary transformer 218 to the top surface 210 of the base 104.

[0032] Downstream of main transformer 214, that is Figure 2 On the right side of the image are a pair of controlled rectifiers, labeled as first controlled rectifier 230 and second controlled rectifier 232, respectively. Each of these controlled rectifiers is electrically coupled at least to the secondary winding of the main transformer 214 and is configured to generate a DC voltage output through rectification. In some examples, first controlled rectifier 230 and second controlled rectifier 232 are six-pulse thyristor rectifier units, which, compared to diode rectifiers, provide improved voltage regulation, have AC and DC fault current limiting, and improved parallel operation capability. Therefore, first controlled rectifier 230 is configured to provide rectification to generate a DC voltage of one polarity, such as +DC volts, while second controlled rectifier 232 is configured to provide rectification to generate a DC voltage of the opposite polarity, such as -DC volts. While other types of controlled rectifiers, such as IGBT (Insulated Gate Bipolar Transistor) rectifier units, can be used, thyristor rectifier units offer higher efficiency and lower heat dissipation. This makes it advantageous to achieve high power density within a compact package, such as in substation 102, when operating at high input voltages such as 33kVAC during DC voltage conversion. Specifically, thyristor rectifier units operate more efficiently than other types of controlled rectifiers, thus requiring less cooling equipment within the substation, freeing up space for other equipment on base 104 and increasing the overall power density of the substation. Other methods can also be used to control the rectifier as an alternative to or complement to the thyristor, maximizing efficiency and thus reducing the substation's cooling requirements.

[0033] In some examples, the first controlled rectifier 230 and the second controlled rectifier 232 are aligned on the top surface 210 of the base 104, generally parallel to the transverse axis A–A, and located between the main transformer 214 and the downstream end 204. More specifically, the first controlled rectifier 230 and the second controlled rectifier 232 may be positioned symmetrically in pairs about the longitudinal axis B–B, or equidistantly between the front side 206 and the rear side 208. Like other components on the top surface 210, the first controlled rectifier 230 and the second controlled rectifier 232 may be secured to the top surface 210 using bolts or other attachments to prevent movement during displacement of the substation 102A.

[0034] In the plan view of substation 102A, downstream of the first controlled rectifier 230 and the second controlled rectifier 232 are one or more low-pass filters 234 and a first DC switching device 236 and a second DC switching device 238. In some examples, such as Figure 2 As shown, the low-pass filter 234 is positioned approximately symmetrical about the longitudinal axis. The first DC switching device 236 and the second DC switching device 238 are located on opposite lateral sides of the low-pass filter 234, approximately parallel to the lateral axis and symmetrical about the longitudinal axis. Therefore, in Figure 2 In the example, the first DC switching device 234 handles positive DC voltage, while the second DC switching device 238 handles negative DC voltage. The low-pass filter 234 may be an inductor-capacitor filter, including, among other components, a relatively large inductor and a small capacitor, configured to eliminate residual ripple voltage on the DC voltage generated by the first controlled rectifier 230 and the second controlled rectifier 232. The ripple voltage of a rectifier implemented using thyristors may be higher than that of a diode rectifier. In some examples, the inductance of the low-pass filter 234 may be in the range of 600µH, and the capacitance may be in the range of 10µF. To help improve the power density of the substation, the low-pass filter 234 may include an air-core inductor. Air-core inductors tend to be larger in size than magnetic-core inductors, but they are significantly more efficient and therefore require less cooling. Therefore, as discussed above regarding the use of thyristor-controlled rectifiers, the use of air-core inductors allows for the reduction or miniaturization of the air conditioning unit 118 within the substation, thereby freeing up space on the base 104 to accommodate other equipment within the limited space of a standard container to handle input voltages ranging from 11kVAC to 33kVAC and DC conversion. The low-pass filter 234, the first DC switching device 236, and the second DC switching device 238 can be secured to the top surface 210 with bolts or other attachments to prevent movement during the displacement of the substation 102A.

[0035] The first DC switching device 236 and the second DC switching device 238 include electrical components configured to connect, disconnect, output, and otherwise switch lines receiving DC input voltages from the first controlled rectifier 230 and the second controlled rectifier 232, respectively. Components in the DC switching devices may include fast DC circuit breakers, such as those commonly used in the rail industry. In some examples, where the first DC switching device 236 and the second DC switching device 238 handle different polarities from the first controlled rectifier 230 and the second controlled rectifier 232, the first DC switching device 236 may provide an output voltage of approximately +1500VDC to connection 126 to supply one of the three lines in conductor rail 140. Similarly, the second DC switching device 238 may provide an output voltage of approximately -1500VDC to connection 126 to supply another of the three lines in conductor rail 140, thereby achieving a total output of approximately 3000VDC at a power of approximately 7.5MW to 10MW. Therefore, the substation 102A can provide up to + / -1500VDC in traction mode as a voltage source to drive loads such as heavy-duty machinery on the conductor rail 140.

[0036] Due to the heat generated by the electrical components within substation 102A, particularly the main transformer 214, several air conditioning units 118 are positioned on the top surface 210 of the base 104. The air conditioning units 118 are positioned to provide balanced regulation within substation 102A and to help distribute weight evenly for more stable movement of the substation during transport and deployment. Figure 2 As shown in the example, two air conditioning units 118 are located adjacent to and upstream of the main transformer 214, on opposite sides of the longitudinal axis B–B, near the front 206 and rear 208, respectively. Similarly, two other air conditioning units 118 are located adjacent to and upstream of the low-pass filter 234, on opposite sides of the longitudinal axis B–B, near the front 206 and rear 208, respectively. Figure 1 In the example, the fifth air conditioning unit in air conditioning unit 118 is located upstream of auxiliary transformer 218 along the front side 206. Air conditioning unit 118 can be implemented as any suitable unit type, and the number, size, and capacity of air conditioning units 118 can be minimized based on the selection of electrical components to maximize thermal efficiency as discussed above. For example, the capacity of air conditioning unit 118 is 25kW. Although air conditioning units 118 can also be mounted on base 104, these units require external air exhaust and therefore can be mounted on the corresponding side wall of their mounting location, such as... Figure 2The rear wall 108 is shown. Although not depicted in the figure, the substation may also include one or more positive air boosters to achieve a small pressure difference between the interior of the substation and the surrounding atmosphere. Positive air boosters help prevent dust and moisture from entering the container, depending on the conditions under which the substation may operate. If space permits, the positive air boosters may be located inside the substation or attached to the exterior of the substation after commissioning.

[0037] To electrically connect the various components within substation 102A, cable 240 spans the entire length of the structure. Cable 240 may be a low-gauge cable with conductors made of copper, aluminum, or similar materials, configured to handle medium to high voltages and large currents. As will be understood, according to Figure 2 The compact footprint allows for short and efficient electrical connections when components are arranged on the base 104. For example, compared to a typical planar arrangement of electrical equipment along the rear side 208, a centrally balanced arrangement of equipment along the transverse axis A–A and longitudinal axis B–B allows the main transformer 214 to be connected more directly to the first controlled rectifier 230 and the second controlled rectifier 232. Shortening the span length of the cable 240 and maintaining uniform parallel connection lengths improves the electrical performance of the substation 102A and reduces losses, such as those caused by harmful parasitic events due to unequal parallel cable lengths.

[0038] In some examples, or at least in certain spans of short-distance direct connections within a substation, cable 240 may include one or more busbars. For instance, busbars may be used to directly connect the positive polarity of the secondary winding of the main transformer 214 to the first controlled rectifier 230 and the negative polarity to the second controlled rectifier 232. Since the controlled rectifiers are positioned side-by-side about the longitudinal axis B–B, each set of busbars is of the same length. The rectifiers are positioned end-to-end along the rear 208 as in a typical substation layout, therefore the cables 240 connecting to different rectifiers will require different lengths. Figure 2 The efficiency of connecting the controlled rectifier to the low-pass filter 234 via cable 240 and then to the first DC switch 236 and the second DC switch 238 is similar.

[0039] at last, Figure 1 Several doors leading to the interior of substation 102A are depicted. Besides... Figure 2 Outside the end gate 116 shown, Figure 2 A first side door 242 and a second side door 244 located within the front wall 106 are also shown. While these doors provide access to substation 102A, the ability of personnel to enter or move within substation 102A may be restricted for security reasons, as further described below.

[0040] Figure 3An example of a layout scheme for substation 102A is shown, and Figure 3 This depicts an alternative plan view of the downstream equipment of the first controlled rectifier 230 and the second controlled rectifier 232. Figure 3 This is a general schematic block diagram 300 showing the layout of components on the base 104 in a variant of top view 200. Compared to top view 200, Figure 2 The difference lies in the low-pass filter and DC switching device on the right side of base 104, downstream of main transformer 214. In short, Figure 3 Top view 200 depicts the layout of a substation typically configured to operate as a voltage source to provide traction for heavy-duty machinery; while schematic block diagram 300 provides a substation that can also be configured to act as a current source to charge the batteries of heavy-duty machinery by providing two outputs (each + / - 1500VDC and 3MW) instead of a single output (3000VDC at 7.5MW to 10MW). Therefore, Figure 2 The substation can be configured to provide any of at least four operating modes: 1x3000VDC as a voltage source in traction mode; 1x1500VDC as a voltage source in traction mode; 1x3000VDC as a current source in high-capacity charger mode; and 2x1500VDC as a current source in high-capacity charger mode. In other cases, these two outputs can be reconfigured to provide + / -750VDC, + / -3000VDC, and other DC output levels as needed.

[0041] and Figure 3 Compared to substations, Figure 2 One difference is that the low-pass filter is enlarged. This enlargement is to achieve higher output voltage fidelity when operating as a current source in high-capacity charger mode. In this charging mode, more robust filtering is needed to adequately control the output current to provide the charging capacity for the load, such as heavy-duty work machinery with onboard batteries. In contrast, for substations operating only as a voltage source in traction mode (such as in...),... Figure 3 In the middle), the voltage output remains at a constant set value, and the low-pass filter can be smaller. In one example, Figure 3 The low-pass filter has an inductance of approximately 6mH and a capacitance of approximately 10µF. (As mentioned above regarding...) Figure 2 The first low-pass filter 302 and the second low-pass filter 304 are discussed as having higher efficiency and lower heat dissipation than using magnetic core inductors, thereby reducing the need for additional cooling units in the substation.

[0042] also, Figure 3The low-pass filters in the circuit are separated by positive and negative polarities. Therefore, the first low-pass filter 302 is coupled to the first controlled rectifier 230, while the second low-pass filter 304 is coupled to the second controlled rectifier 232. Due to the increased filter size, the first low-pass filter 302 and the second low-pass filter 304 are located between the controlled rectifier and the DC switching device, i.e., upstream of the DC switching device, instead of being aligned with the DC switching device as shown in top view 200. The DC switching device has also been expanded, with positive and negative switching devices for each half of the output. Therefore, the first positive DC switching device 306 and the first negative DC switching device 308 are electrically coupled to the first low-pass filter 302, while the second positive DC switching device 310 and the second negative DC switching device 312 are electrically coupled to the second low-pass filter 304. Figure 4 As shown, schematic block diagram 300 provides two independent outputs from each of the first DC switching device and the second DC switching device.

[0043] Among other characteristics, such as Figure 5 and Figure 1 As illustrated, the footprint of base 104 increases power density due to the arrangement of electrical components within a fixed space; transport efficiency is improved by housing it in a standardized and commercially available container; and the weight of substation 102A is evenly distributed both laterally and longitudinally. Therefore, substation 102A can be efficiently packaged and transported to remote areas, such as by being lifted by a crane and loaded into a container conforming to ISO high-cubic-meter container dimensions. Upon arrival at its destination, substation 102A is essentially ready for operation without the need for additional equipment or expansion beyond the footprint of base 104. Furthermore, as explained below, the planar layout of the equipment away from walls (such as the front 206 or rear 208) also makes substation 102A safer for operators, preventing accidental arcing.

[0044] Figure 4 and Figure 2 They are shown respectively Figure 1 to Figure 5 The substation 102A is shown in the front view 400 and right view 500 in its deployed layout. As discussed above, a series of piers 124 elevate the substation 102A to a level above ground to protect the structure from elements on the ground and to prevent access to the substation 102A via end door 116, first side door 242, or second side door 244. In some examples, the piers 124 elevate the base 104 to approximately one meter or more above ground. At these heights, personnel (such as...) Figure 6Operator 402 may have to climb into substation 102A or use a ladder or similar lift. Therefore, while still allowing access to substation 102A for maintenance as needed, the pier 124 provides a simple way to restrict access through the door and improve worker safety from accidental arc discharge.

[0045] As an additional security feature, in some examples, end door 116, first side door 242, and second side door 244 may include mechanical fasteners 404 and microswitches (not shown), configured to secure the doors in the closed position. The mechanical fasteners 404 may be bolts, locks, or similar devices arranged to prevent the doors from being opened and are intended to be installed or activated when substation 102A is in operation and poses a risk of arc discharge to personnel. The microswitches may be installed between the doors and door frames of substation 102A and are configured to open or close a circuit when one of end door 116, first side door 242, or second side door 244 is opened. When a door is opened, the microswitches trigger an alarm or alert signaling an intrusion into substation 102A. The alarm may be visual, audible, tactile, or a combination thereof. Other arrangements to prevent entry into substation 102A, such as motion sensors or infrared beam sensors, are also feasible and consistent with the principles of this disclosure.

[0046] To enhance operator safety, while restricting access to substation 102A, substation 102A may include equipment for operator control or configuration of the substation, such as workstation 502 located within the second end wall 112. Figure 6 In some examples, workstation 502 includes computer equipment equipped with a touchscreen display for operator 402 to interact with. Workstation 502 may be installed within the second end wall 112 at a height approximately above ground level, roughly equivalent to the head height of an average person. By being able to monitor and control the operation of substation 102A from workstation 502, operator 402 reduces the need to enter substation 102A when equipment is operating and there is a risk of arcing.

[0047] From such Figure 1 to Figure 5 The architectural shift of the illustrated system 100 and substation 102, Figure 2 This is a flowchart representing process 600 for assembling a mobile substation. Process 600 is illustrated as a logic flowchart, the operation of which represents a series of operations that can be implemented manually or by mobile devices involving hardware, software, or a combination thereof. The order in which the operations are described is not intended to be construed as limiting, and any number of the described operations can be combined in any order and / or in parallel to implement the process.

[0048] exist Figure 6In example method 600, step 602 includes providing a rectangular platform having a longitudinal axis and a transverse axis. For example... Figure 2 As shown in the example, the base 104 has a top surface 210, on which the transverse axis A–A and the longitudinal axis B–B intersect at a center 212. The transverse axis A–A extends through the center 212 between the upstream end 202 and the downstream end 204, while the longitudinal axis B–B extends through the center 212 between the front side 206 and the rear side 208.

[0049] On a rectangular platform, electrical equipment for converting AC power to low-voltage DC power is assembled. Specifically, in the second step 604 of method 600, a main transformer is attached to the rectangular platform, symmetrical about the longitudinal axis and about the transverse axis. In some examples, the main transformer 214 is located near the center 212, such as... Figure 2 As illustrated. In this arrangement, the main transformer 214 is located substantially equidistantly between the front side 206 and the rear side 208 within the substation 102A, and equidistantly between the upstream end 202 and the downstream end 204.

[0050] Figure 3 Step 606 of the method involves attaching an AC voltage switching device upstream of the main transformer, and generally parallel to the transverse axis. Therefore, relative to the main transformer 214, Figure 3 The AC switchgear 216 is located closer to the upstream end 202. In some implementations, the auxiliary transformer 218 is also located upstream of the main transformer 214 and is aligned with the AC switchgear 216 and is generally parallel to the transverse axis A–A.

[0051] In step 608, a pair of controlled rectifiers (converting the AC voltage of the main transformer to DC voltage) are attached to the rectangular platform downstream of the main transformer. Furthermore, the pair of controlled rectifiers are aligned together, approximately parallel to the transverse axis. (Reference) Industrial applicability As discussed above, the first controlled rectifier 230 and the second controlled rectifier 232 are positioned and attached to the base 104, downstream of the main transformer 214. The pair of controlled rectifiers are aligned together, generally parallel to the transverse axis A–A, and are substantially equidistant between the front side 206 and the rear side 208.

[0052] In step 610, one or more low-pass filters are attached downstream of the pair of controlled rectifiers and positioned symmetrically about the longitudinal axis. For example, low-pass filter 234 may be located between the controlled rectifier and the downstream end 204, while being placed along the longitudinal axis B–B so as to be substantially equidistant between the front side 206 and the rear side 208. In other examples, such as Figure 1 to Figure 5As shown, the one or more low-pass filters may be a first low-pass filter 302 and a second low-pass filter 304, which are positioned substantially parallel to the transverse axis A–A, immediately downstream of the first controlled rectifier 230 and the second controlled rectifier 232.

[0053] The final step 612 involves attaching the DC voltage switching devices to one end of the platform, symmetrical about the longitudinal axis. In one example, the first DC switch 236 and the second DC switch 238 are located adjacent to each other at the downstream end 204 and on opposite sides of the longitudinal axis B–B. Therefore, the first DC switch 236 and the second DC switch 238 may be located on opposite sides of the low-pass filter 234. In another example, the DC switching devices may be separate to handle different paths from the controlled rectifier and the low-pass filter, such as… ​ As shown. In this case, the first positive DC switch 306 and the first negative DC switch 308 are located on one side of the base 104, such as closer to the rear wall 108 than the front wall 106, while the second positive DC switch 310 and the second negative DC switch 312 are closer to the front wall 106 than the rear wall 108.

[0054] As discussed elsewhere in this disclosure, after assembling these electrical components on base 104 according to method 600, substation 102A can be lifted and inserted, or otherwise installed into a container constructed to conform to the "high cubic" ISO standard, for transport to its destination. Thus, substation 102A can be moved and transported in a balanced manner and can be commissioned on-site, providing high power density to energy delivery systems to power high-voltage heavy-duty machinery with minimal on-site assembly steps.

[0055] Those skilled in the art will understand that the principles of this disclosure are not limited to the specific examples discussed or illustrated in the figures. For example, while specific voltage and power ratings have been disclosed, the modular substation of this disclosure is applicable to any type of voltage and power rating required for implementation. Furthermore, it should be understood that the order in which components are arranged and attached to the substation base can be any order that facilitates assembly. Moreover, while this disclosure relates to a modular, scalable substation for providing DC power to heavy-duty machinery in locations such as mines, any electrical load using high-voltage DC power can benefit from the disclosed and claimed examples and techniques.

[0056] ​

[0057] This disclosure provides a system and method for a scalable modular substation for transmitting electrical energy in DC voltage to loads on conductive rails, such as mining machinery. The substation is modular and scalable, converting AC voltage to DC voltage to drive high-voltage, high-current DC loads such as heavy-duty machinery transporting loads within a mine. The substation is designed to fit within a standard high-cubic-meter ISO container and includes a main transformer attached at the center of a rectangular base. A pair of controlled rectifiers are located on the base, downstream of the main transformer, aligned parallel to the transverse axis of the base and approximately symmetrical about its longitudinal axis. This arrangement of components along the longitudinal axis on the base, along with low-pass filters and switching equipment, achieves high power density for the substation, provides balanced mass to ensure stability during transport and installation, and helps protect personnel from accidental arcing.

[0058] As mentioned above ​ The example system mentioned, used for transmitting electrical energy in DC voltage form, includes a modular substation and conductive rails. Modular substation 102A is configured to convert AC voltage input to DC voltage output and includes electrical equipment arranged on a rectangular base 104. In some examples, a main transformer 214 is located at the center of the base, an AC switchgear 216 is attached to the base upstream of the main transformer, and a pair of controlled rectifiers are located downstream of the main transformer. A first controlled rectifier 230 and a second controlled rectifier 232 are arranged generally parallel to the transverse axis of the base 104 and are substantially equidistant between the two sides of the base 104. A low-pass filter and DC switchgear are also balanced between the two sides of the base 104, symmetrical about the longitudinal axis of the base 104, and located downstream of the controlled rectifiers. This arrangement on the base 104, and the selection of electrical performance for high efficiency and low heat output, enables the substation 102A to achieve high power density and allows it to be housed within a container conforming to the dimensions of a standard high-cubic-meter ISO shipping container. In addition, the placement of the equipment balanced the mass of the substation, ensuring stability during transportation and installation.

[0059] In the examples of this disclosure, substation 102, together with conductor rail 140, constitutes a modular, scalable system 100 for distributing DC voltage to high-voltage, high-current loads such as heavy-duty machinery. The arrangement of electrical components (particularly the main transformer 214, the first controlled rectifier 230, and the second controlled rectifier 232) is symmetrical with respect to the longitudinal axis B–B, allowing for the use of shorter parallel conductors within cable 240 and helping to avoid cable routing difficulties and potential parasitic events. Its compact form factor and modular design make it easy to transport to the work site and deploy quickly compared to conventional designs that require on-site assembly. This results in greater efficiency and resource utilization at the work site. Additional features such as reduced passage space on base 104, piers 124 for elevating the substation above the step level, and mechanical fasteners 404 and microswitch sensors on doors all work together to improve personnel safety and prevent arc discharge injuries that would otherwise occur to operators inside substation 102A during high-voltage operation.

[0060] Unless explicitly excluded, the use of the singular to describe a component, structure, or operation does not preclude the use of multiple such components, structures, operations, or their equivalents. As used herein, the word "or" refers to any possible permutation of a set of items. For example, the phrase "A, B, or C" refers to at least one of A, B, or C, or any combination thereof, such as A; B; C; A and B; A and C; B and C; A, B, and C; or multiples of any item, such as A and A; B, B, and C; A, A, B, C, and C, etc.

[0061] Approximate terms are intended to include a range of values ​​for a function or result that does not change the disclosed structure or process. For example, the term "approximately" generally refers to a range of values ​​that a person skilled in the art considers equivalent to or to have the same function or result. Similarly, the antecedent "roughly" means largely (but not entirely) the same form, manner, or degree, and that a particular element will have a range of configurations that a person skilled in the art considers to have the same function or result. As an example, "roughly flat" does not need to be exactly flat, but can also include minor variations of a few degrees based on the context.

[0062] While aspects of this disclosure have been specifically shown and described with reference to the above embodiments, those skilled in the art will understand that various additional embodiments can be conceived by modifying the disclosed systems and methods without departing from the spirit and scope of the disclosure. Such embodiments should be understood to fall within the scope of the invention as defined by the claims and any equivalents.

Claims

1. A system (100) for transmitting electrical energy in the form of DC voltage, the system comprising: Modular substations (102A, 102B), configured to receive AC voltage input and provide DC voltage output, comprising: A base (104) having a generally planar rectangular shape, the base (104) comprising: The top surface (210) extends longitudinally from the first end (202) to the second end (204) and laterally from the front side (206) to the rear side (208). Along the longitudinal axis of the top surface (210), the longitudinal axis is approximately centered between the front side (206) and the rear side (208), and Along the transverse axis of the top surface (210), the transverse axis is approximately centered between the first end (202) and the second end (204). AC voltage switching device (216), the AC voltage switching device being configured to receive the AC voltage input from an external power source. An auxiliary transformer (218) is configured to be electrically coupled to the AC voltage switching device (216). The auxiliary transformer (218) and the AC voltage switching device (216) are aligned on the top surface (210) of the base (104), generally parallel to the transverse axis, and located between the transverse axis and the first end (202). The main transformer (214) has a primary winding and a secondary winding, the primary winding being electrically coupled to the AC voltage switching device (216). The main transformer (214) is located on the top surface (210) of the base (104), approximately at the intersection of the longitudinal axis and the transverse axis. A pair of controlled rectifiers (230, 232), electrically coupled at least to the secondary winding of the main transformer (214) and configured to generate the DC voltage output, are aligned on the top surface (210) of the base (104), generally parallel to the transverse axis, and located between the main transformer (214) and the second end (204). One or more low-pass filters (234) electrically coupled to the pair of controlled rectifiers (230, 232), the low-pass filters (234) being positioned substantially parallel to the transverse axis and symmetrical about the longitudinal axis between the pair of controlled rectifiers (230, 232) and the second end (204). DC voltage switching devices (236, 238), electrically coupled to the one or more low-pass filters (234) and configured to receive the DC voltage output from the one or more low-pass filters (234), the DC voltage switching devices being positioned near the second end (204) of the base (104), generally parallel to the transverse axis and symmetrical about the longitudinal axis; and A conductive rail (140), electrically coupled to the DC voltage switching device (236, 238), is configured to transmit the DC voltage output to a load connected to the conductive rail (140).

2. The system (100) according to claim 1, further comprising: The first pair of air conditioning units (118) are respectively positioned close to the front side (206) and the rear side (208), and are located between the transverse axis and the first end (202); and The second air conditioning unit (118) is positioned close to the front side (206) and the rear side (208), respectively, and is located between the transverse axis and the second end (204).

3. The system (100) according to any one of claims 1 or 2, further comprising: A pier (124) is located between the base (104) and the ground, and its structure is designed to provide vertical support to the modular substations (102A, 102B). The pier (124) is configured to raise the base (104) to a height of at least one meter above the ground.

4. The system (100) according to any one of claims 1 to 3, wherein the AC voltage input is at least 11kV three-phase AC, and the DC voltage output is at least + / –1.1kV DC.

5. A mobile substation (102A, 102B), said mobile substation comprising: A rectangular platform (104) having a top surface (210) with a geometric center (212) located between an upstream end (202) and a downstream end (204) and between a first side (206) and a second side (208), wherein a longitudinal axis passes through the geometric center (212) and is generally parallel to the first side (206) and the second side (208) along the top surface (210), and a transverse axis passes through the geometric center (212) and is generally parallel to the upstream end (202) and the downstream end (204) along the top surface (210). A main high-voltage transformer (214) is attached to the top surface (210) and is symmetrical about the longitudinal axis and about the transverse axis; AC voltage switching device (216), the AC voltage switching device is attached to the top surface (210), located upstream of the main high voltage transformer (214), and generally parallel to the transverse axis; A pair of controlled rectifiers (230, 232) are attached to the top surface (210), located downstream of the main high-voltage transformer (214), and are arranged together generally parallel to the transverse axis. One or more low-pass filters (234) are attached to the top surface (210), located downstream of the pair of controlled rectifiers (230, 232), and symmetrical about the longitudinal axis; and DC voltage switching devices (236, 238) are attached to the top surface (210), near the downstream end (204), generally parallel to the transverse axis, and symmetrical about the longitudinal axis.

6. The mobile substation (102A, 102B) according to claim 5, further comprising: An auxiliary high-voltage transformer (218) is attached to the top surface (210) and located upstream of the main high-voltage transformer (214). The auxiliary high-voltage transformer (218) and the AC voltage switching device (216) are arranged approximately parallel to the transverse axis.

7. The mobile substation (102A, 102B) according to any one of claims 5 or 6, wherein the pair of controlled rectifiers (230, 232) are symmetrical about the longitudinal axis.

8. The mobile substation (102A, 102B) according to any one of claims 5 to 7, wherein the one or more low-pass filters (234) and the DC voltage switching devices (236, 238) are arranged together in alignment, substantially parallel to the transverse axis.

9. The mobile substation (102A, 102B) according to any one of claims 5 to 7, wherein the DC voltage switching device (236, 238) is located downstream of the one or more low-pass filters (234).

10. The mobile substation (102A, 102B) according to any one of claims 5 to 9, further comprising: Walls (106, 108, 110, 112) are erected vertically upward from the upstream end (202), the downstream end (204), the first side (206), and the second side (208) of the rectangular platform, respectively, wherein the mobile substation (102B) is suitable for housing in a standard intermodal high cubic container conforming to ISO 668:2020 Series 1AAA.

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