TWI907112B - Power distribution system - Google Patents

Abstract

A power distribution system includes a frame, at least one busbar and a plurality of switch modules. The busbar is disposed on the frame and is configured to couple to at least one input line. Each switch module includes a switch module main body and a control unit. The switch module main body is detachably disposed on the frame and has an input interface and an output interface. The input interface is coupled to the control unit and connected to the busbar, and the output interface is coupled to the control unit and configured to couple to at least one output line. The control unit is disposed in the switch module main body and includes a relay and a control circuit board coupled to each other.

Description

Power distribution system

This invention relates to an electrical system, and more particularly to a power distribution system.

Traditional distribution panels lack intelligent control functions, requiring the separate installation of an intelligent control panel to provide measurement and control capabilities. This configuration, due to the large number of circuits, necessitates the installation of multiple intelligent control panels, making it unsuitable for outdoor or space-constrained installations, and its wiring is complex. Currently, some integrated distribution panels combine the distribution panel and intelligent control panel, eliminating the need for a separate intelligent control panel. However, integrated distribution panels have numerous components and complex assembly; their circuit count cannot be varied, requiring the development of multiple sets of molds to correspond to products with different circuit counts, resulting in low production efficiency and high manufacturing costs. Furthermore, whether it's a traditional distribution panel or an existing integrated distribution panel, its numerous switching and measuring components are not modularly designed but share a single control circuit board. Therefore, when a single channel fails, the entire panel must be disassembled for repair, resulting in low repair efficiency and significantly increased power outage time for users.

This invention provides a power distribution system that improves maintenance efficiency.

The power distribution system of this invention includes a frame, at least one bus, and multiple switching modules. The bus is disposed on the frame and coupled to at least one input line. Each switching module includes a switching module body and a control unit. The switching module body is detachably disposed on the frame and has an input interface and an output interface. The input interface is coupled to the control unit and connected to the bus, and the output interface is coupled to the control unit and coupled to at least one output line. The control unit is disposed within the switching module body and includes a relay and a control circuit board coupled to each other.

In one embodiment of the present invention, each of the aforementioned switching modules further includes a shunt and a voltage measurement unit, the shunt and the voltage measurement unit being disposed within the main body of the switching module and coupled to the control circuit board.

In one embodiment of the present invention, the aforementioned power distribution system further includes multiple connection terminals and multiple circuit breakers. The connection terminals are disposed on the frame and correspond to the switching modules respectively. Each connection terminal is plugged into the output interface of the corresponding switching module. The circuit breakers are detachably disposed on the frame and connected to the connection terminals respectively. Each output interface is coupled to an output line through the corresponding connection terminal and the corresponding circuit breaker.

In one embodiment of the invention, the frame includes a back panel and a base connected together. The base has an opposing load-bearing surface and a bottom surface. An accommodating space exists between the back panel and the bottom surface. Switch modules are disposed within the accommodating space, and circuit breakers are disposed on the load-bearing surface.

In one embodiment of the present invention, the aforementioned switch module body has two locking holes, and the base has multiple openings corresponding to the locking holes of the switch module body. Each switch module further includes two locking attachments, each passing through a corresponding opening to lock onto the corresponding locking holes of the switch module body, and respectively abutting against the busbar and the corresponding connection terminal.

In one embodiment of the invention, the circuit breakers described above are adapted to be detached from the housing to expose portions of these openings.

In one embodiment of the present invention, the aforementioned back panel includes multiple sub-back panels, which are detachably connected in sequence.

In one embodiment of the present invention, the aforementioned base includes multiple sub-bases, which are detachably connected in sequence.

In one embodiment of the present invention, the backplate has a plurality of first slide rails, the base has a plurality of second slide rails, and the switch module body has a plurality of slide grooves, thereby slidingly disposed between a first slide rail and a second slide rail.

In one embodiment of the present invention, the main body of the aforementioned switch module has a latch that engages with the base.

In one embodiment of the invention, the aforementioned base has multiple openings corresponding to the switch modules, and the latches are adapted to be pressed through the corresponding openings to disengage from the base.

In one embodiment of the invention, the aforementioned accommodating space comprises two adjacent sub-accommodating spaces, with some of the switch modules arranged sequentially within one sub-accommodating space and others arranged sequentially within the other sub-accommodating space.

In one embodiment of the present invention, the bus has a plurality of first bus terminals and a plurality of second bus terminals. The first bus terminals are inserted into the switching modules within a sub-accommodating space along a first direction, and the second bus terminals are inserted into the switching modules within another sub-accommodating space along a second direction opposite to the first direction.

In one embodiment of the invention, the aforementioned power distribution system further includes a housing, wherein the dimension of the housing is W in the width direction of the power distribution system, the dimension of each switch module is L, the installation clearance between each switch module and the housing is a, the installation width of the bus is b, and W = 4*L + 2*a + b < 362 mm.

In one embodiment of the present invention, each of the aforementioned connection terminals has a first end and a second end, the first end being connected to a corresponding circuit breaker, and the second end being connected to a corresponding output interface. Each connection terminal passes through a housing such that the housing is positioned between the first end and the second end, the second end portion being within an accommodating space. A bus is disposed on a backplate and positioned between the backplate and the second end.

In one embodiment of the invention, the frame further includes multiple support members that support the backplate and the base, with each support member positioned between two adjacent switch modules.

In one embodiment of the present invention, the aforementioned supporting members are I-beam shaped structures.

In one embodiment of the present invention, the aforementioned bus includes a first phase bus and a second phase bus, and the frame further includes at least one insulating post, which is supported between the back plate and the base and is isolated between the first phase bus and the second phase bus.

In one embodiment of the invention, the aforementioned switch modules are adapted to be independently disassembled and separated from the other switch modules, circuit breakers, and frame.

In one embodiment of the invention, these switching modules are interconnected via a daisy-chain topology.

Based on the above, the power distribution system of this invention comprises multiple independent switching modules, each with its own control circuit board, rather than sharing a single circuit board. Therefore, when a single channel of the power distribution system fails, only the corresponding switching module needs to be removed for repair, instead of dismantling all switching modules as a whole, thereby improving maintenance efficiency.

50:Input line

60:Output line

100: Power Distribution System

110: Shell

120: Frame

122: Backplate

1221: First sliding rail

122S: Sub-backplate

124: Seat

1241: Second sliding rail

1242: Open

124a: Load-bearing surface

124b: Bottom surface

124S: Subsidiary body

126: Support component

128: The Pillar of Severance

130: Cover Body

140: Switch Module

1401: Connection Port

141: Lock Attachments

142: Switch Module Main Body

1421: Slide

1422: Hook

142a: Input Interface

142b: Output Interface

144: Control Unit

1441: Relay

1442: Control Circuit Board

146: Diverter

148: Voltage Measurement Unit

150: Circuit breaker

160A: First Phase Bus

160B: Second Phase Bus

162A, 162B: First bus terminal

164A, 164B: Second bus terminals

170: Connection terminal

170a: First end

170b: Second end

D1: First Direction

D2: Second Direction

H1: Locking hole

H2: Opening

K1: Hook

K2: Clip slot

P1: Pin

P2: Pin Hole

S: Storage space

S1, S2: Sub-accommodation space S1, S2: Sub-accommodation space

Figure 1 is a front view of a power distribution system according to an embodiment of the present invention.

Figure 2 is an exploded view of the power distribution system shown in Figure 1.

Figure 3 is an exploded view of some components of the power distribution system shown in Figure 2.

Figure 4 is a schematic diagram of the power distribution system shown in Figure 1, connecting the input and output lines.

Figure 5 is a partial bottom view of the power distribution system shown in Figure 1.

Figure 6 shows a partial structure of the power distribution system in Figure 3.

Figure 7 shows a partial structure of the power distribution system in Figure 3.

Figure 8 is an exploded view of some components of the power distribution system shown in Figure 7.

Figure 9 illustrates the internal structure of the switch module in Figure 5.

Figures 10 and 11 are perspective views of some components of the power distribution system shown in Figure 7 from different viewpoints.

Figure 12 is a front view of the switching module in Figure 6.

Figure 13 is a front view of a partial structure of the power distribution system shown in Figure 6.

Figure 14 is a side view of a partial structure of the power distribution system shown in Figure 6.

Figure 15 is a cross-sectional view of the power distribution system shown in Figure 13 along line I-I.

Figure 16 is a front view of a partial structure of the power distribution system shown in Figure 15.

Figure 17 is a partial perspective view of some components of the power distribution system shown in Figure 6.

Figure 18 is a partial perspective view of some components of the power distribution system shown in Figure 17.

Figure 19 is a partial perspective view of some components of the power distribution system shown in Figure 6.

Figure 20 is a front view of the power distribution system shown in Figure 19.

Figure 21 is a partial side view of some components of the power distribution system shown in Figure 6.

Figure 22 illustrates part of the structure of the base in Figure 3.

Figure 23 is a partially enlarged view of the base shown in Figure 22.

Figures 24A and 24B illustrate the assembly method of the sub-base of Figure 22.

Figure 25 illustrates part of the structure of the back panel in Figure 3.

Figure 26 illustrates the two switch modules of Figure 5 being moved away from the two sub-accommodation spaces.

Figure 1 is a front view of a power distribution system according to an embodiment of the present invention. Figure 2 is an exploded view of the power distribution system of Figure 1. Figure 3 is an exploded view of some components of the power distribution system of Figure 2. Referring to Figures 1 to 3, the power distribution system 100 of this embodiment includes a housing 110, a frame 120, a cover 130, multiple switch modules 140, and multiple circuit breakers 150. The frame 120 is disposed within the housing 110 and supports the switch modules 140 and the circuit breakers 150. The cover 130 is hinged to the housing 110 and covers the frame 120, switch modules 140, and circuit breakers 150 within the housing 110.

Figure 4 is a schematic diagram of the power distribution system of Figure 1, showing the connection of the input and output lines. Referring to Figure 4, the input line 50 (e.g., an AC line) is used to input power into the switching module 140. Power is then output from the switching module 140 through the circuit breaker 150 to the output line 60 (e.g., an AC line).

Figure 5 is a partial bottom view of the power distribution system of Figure 1, Figure 6 is a partial structure of the power distribution system of Figure 3, and Figure 7 is a partial structure of the power distribution system of Figure 3. For clarity, some switch modules 140 and some circuit breakers 150 in Figures 5 to 7 are shown in a removed state. Figure 8 is an exploded view of some components of the power distribution system of Figure 7. Referring to Figures 5 to 8, specifically, each switch module 140 of this embodiment includes a switch module body 142, which is detachably mounted on the frame 120 and has an input interface 142a and an output interface 142b. The power distribution system 100 further includes at least one bus (shown as a first phase bus 160A and a second phase bus 160B) and a plurality of connection terminals 170. First phase bus 160A and second phase bus 160B are disposed in the housing 120 and coupled to the input line 50 shown in FIG. 2. Input interface 142a of part of the switch module body 142 is connected to the first phase bus 160A, and input interface 142a of another part of the switch module body 142 is connected to the second phase bus 160B.

These connection terminals 170 are disposed on the frame 120 and correspond to the switch modules 140 respectively. Each connection terminal 170 is plugged into the output interface 142b of the corresponding switch module body 142 of the switch module 140. These circuit breakers 150 are detachably disposed on the frame 120 and connected to the connection terminals 170 respectively. The output interface 142b of each switch module body 142 is coupled to the output line 60 shown in FIG. 2 through the corresponding connection terminal 170 and the corresponding circuit breaker 150. Furthermore, these switch modules 140 are coupled to each other, for example, through their connection ports 1401 via a daisy chain topology, for the transmission of signals and power between them.

Figure 9 illustrates the internal structure of the switching module of Figure 5. Referring to Figure 9, each switching module 140 of this embodiment further includes a control unit 144 disposed within the switching module body 142. The input interface 142a and output interface 142b of the switching module body 142 are coupled to the control unit 144. The control unit 144 includes a relay 1441 and a control circuit board 1442 coupled to each other. In addition, each switching module 140 further includes a shunt 146 and a voltage measurement unit 148, which are disposed within the switching module body 142 and coupled to the control circuit board 1442. Specifically, the power enters the switching module 140 from the input interface 142a, reaches the relay 1441, then passes through the control circuit board 1442 to the shunt 146, and then through the control circuit board 1442 to the output interface 142b. The relay 1441 is used to switch the power transmission of the switching module 140, the shunt 146 is used to sense the current, the voltage measurement unit 148 is used to measure the voltage, and the control circuit board 1442 is used to control at least a portion of the switching module 140 including the above-mentioned functions. The detailed functions and operating principles of the control circuit board 1442, the relay 1441, the shunt 146, and the voltage measurement unit 148 are known technologies in the field of distribution panels and will not be elaborated here.

Compared to traditional switchboards, at least one feature of the power distribution system 100 of this embodiment is that, as described above, the power distribution system 100 includes multiple independent switching modules 140, each of which has a control circuit board 1442 integrating a voltage measurement unit 148, instead of sharing a single circuit board. Thus, each switching module 140 can be independently disassembled and separated from other switching modules 140, circuit breakers 150, and the frame 120. Accordingly, when a single channel of the power distribution system 100 fails, only the corresponding switching module 140 can be removed for maintenance, without the need to completely dismantle all switching modules 140, thereby improving maintenance efficiency.

Figures 10 and 11 are perspective views of some components of the power distribution system of Figure 7 from different viewpoints. Referring to Figures 7, 10 and 11, in this embodiment, the frame 120 includes a back plate 122 and a base 124 connected together. The base 124 has a load-bearing surface 124a and a bottom surface 124b facing each other. There is an accommodating space S between the back plate 122 and the bottom surface 124b of the base 124. The switching modules 140 are disposed in the accommodating space S, and the circuit breakers 150 are disposed on the load-bearing surface 124a of the base 124. Furthermore, each connection terminal 170 has a corresponding first end 170a and a second end 170b. The first end 170a is connected to the corresponding circuit breaker 150, and the second end 170b is connected to the output interface 142b of the corresponding switching module 140. Each connection terminal 170 passes through the housing 124, such that the housing 124 is located between the first end 170a and the second end 170b. The second end 170b is located within the accommodating space S. The first phase bus 160A and the second phase bus 160B are disposed on the back plate 122, located between the back plate 122 and the second end 170b.

In this configuration, the frame 120, with its backplate 122 and base 124, forms a double-layered open mounting structure, and the buses (first phase bus 160A and second phase bus 160B) and the first ends 170a and second ends 170b of the connection terminals 170 form a three-layer external terminal block. Thus, the circuit breaker 150 and the switching module 140 can be conveniently installed on the upper and lower layers of the frame 120 respectively and smoothly electrically connected to the connection terminals 170 through the buses (first phase bus 160A and second phase bus 160B).

Furthermore, the accommodating space S of this embodiment includes two adjacent sub-accommodating spaces S1 and S2. Some of the switching modules 140 are arranged sequentially in sub-accommodating space S1, and the other part of the switching modules 140 are arranged sequentially in sub-accommodating space S2. As shown in FIG11, the first phase bus 160A has multiple first bus terminals 162A and multiple second bus terminals 164A. These first bus terminals 162A are inserted into the partial switching modules 140 in sub-accommodating space S1 along a first direction D1, and these second bus terminals 164A are inserted into the partial switching modules 140 in sub-accommodating space S2 along a second direction D2 opposite to the first direction D1. Similarly, as shown in FIG. 11, the second phase bus 160B has multiple first bus terminals 162B and multiple second bus terminals 164B. The first bus terminals 162B are inserted along a first direction D1 into portions of the switching modules 140 within the sub-accommodation space S1, and the second bus terminals 164B are inserted along a second direction D2 into portions of the switching modules 140 within the sub-accommodation space S2. This configuration allows the buses (first phase buses 160A and second phase buses 160B) and the switching modules 140 to be compactly arranged within the accommodation space S, saving space and reducing the overall device size.

Figure 12 is a front view of the switching module of Figure 6. Figure 13 is a front view of a partial structure of the power distribution system of Figure 6. Referring to Figures 6, 7, 12, and 13, each switching module body 142 of this embodiment has two locking holes H1, and the base 124 has multiple openings H2, which correspond to the locking holes H1 of the switching module bodies 142 respectively. Each circuit breaker 150 is adapted to be separated from the base 124 to expose a portion of the openings H2. Each switch module 140 further includes two locking attachments 141 (shown in Figures 12 and 13). The two locking attachments 141 pass through corresponding openings H2 to lock onto corresponding locking holes H1 of the switch module body 142, and as shown in Figure 9, respectively abut against the terminal of the corresponding bus (shown as the first bus terminal 162A of the first phase bus 160A) and the second end 170b of the corresponding connection terminal 170.

Figure 14 is a side view of a partial structure of the power distribution system of Figure 6. Referring to Figures 8 and 14, the backplate 122 of this embodiment has multiple first slide rails 1221, the base 124 has multiple second slide rails 1241, and each switch module body 142 has multiple sliding grooves 1421, which allow it to slide smoothly between a first slide rail 1221 and a second slide rail 1241. Accordingly, each switch module body 142 can be smoothly installed onto the frame 120 by being guided by the first slide rails 1221 and the second slide rails.

Figure 15 is a cross-sectional view of the power distribution system of Figure 13 along line I-I. Figure 16 is a front view of a partial structure of the power distribution system of Figure 15. Referring to Figures 15 and 16, each switch module body 142 has a latch 1422, and the base 124 has multiple openings 1242 corresponding to the switch modules 140. The latches 1422 engage with the openings 1242 of the base 124 to securely mount the switch module body 142 to the frame 120. The latches 1422 are adapted to be pressed through the corresponding openings 1242 to disengage from the base 124, allowing the switch module body 142 to be removed from the frame 120.

Figure 17 is a partial perspective view of some components of the power distribution system of Figure 6. Figure 18 is a partial perspective view of some components of the power distribution system of Figure 17. Referring to Figures 17 and 18, the frame 120 of this embodiment further includes multiple support members 126, which are supported between the back plate 122 and the base 124. As shown in Figure 18, each support member 126 has an I-beam structure and a small thickness, allowing each support member 126 to be positioned between two adjacent switch modules 140 without excessively occupying the configuration space of the switch modules 140.

Figure 19 is a partial perspective view of some components of the power distribution system of Figure 6. Figure 20 is a front view of the power distribution system of Figure 19. Figure 21 is a partial side view of some components of the power distribution system of Figure 6. Referring to Figures 11 and 19 to 21, the frame 120 of this embodiment further includes a plurality of insulating posts 128, which are supported between the back plate 122 and the base 124 and are isolated between the terminals of the first phase bus 160A (first bus terminal 162A and second bus terminal 164A) and the terminals of the second phase bus 160B (first bus terminal 162B and second bus terminal 164B). As described above, the insulating post 128 serves both as structural support and as an isolation point for electrical currents of different phases, thus simplifying the structural design of the frame 120 and saving space.

Figure 22 illustrates a portion of the structure of the base of Figure 3. Figure 23 is a partial enlarged view of the base of Figure 22. Figures 24A and 24B illustrate the assembly method of the sub-bases of Figure 22. Referring to Figures 3 and 22 to 24B, the base 124 of this embodiment includes a plurality of sub-bases 124S, which are detachably connected in sequence. In detail, the pin P1 (indicated in Figure 23) of each sub-base 124S can be inserted into the pin hole P2 (indicated in Figure 23) of another sub-base 124S, and the latch K1 of each sub-base 124S can be engaged with the latch slot K2 of another sub-base 124S as shown in Figures 24A to 24B, so as to quickly complete the engagement of the two sub-bases 124S without the need for other fasteners. Figure 25 illustrates a portion of the backplane structure of Figure 3. Similarly, the backplane 122 of this embodiment includes multiple sub-backplanes 122S, which are detachably connected sequentially. Their connection methods are the same as or similar to those of the sub-base 124S, and will not be repeated here. With this configuration, the user can change the number of sub-bases 124S and sub-backplanes 122S according to the circuit requirements of the power distribution system, flexibly expanding the number of circuits to easily meet customized needs.

Figure 26 illustrates the two switch modules from Figure 5 being moved out of their respective storage spaces. Referring to Figure 26, in the width direction of the power distribution system 100 parallel to the first direction D1 and the second direction D2, the dimension of the housing 110 is W, the dimension of each switch module 140 is L, the installation clearance between each switch module 140 and the housing 110 is a, and the installation width of the busbar is b. Therefore, W = 4*L + 2*a + b < 362mm (a common width for European and American distribution boxes). Accordingly, sufficient space can be provided for the removal of the switch modules 140 while minimizing the width of the housing 110 as much as possible.

In summary, the power distribution system of this invention comprises multiple independent switching modules, each with its own control circuit board, rather than sharing a single circuit board. Therefore, when a single channel of the power distribution system fails, only the corresponding switching module needs to be removed for repair, instead of dismantling all switching modules, thereby improving maintenance efficiency.

120: Frame

122: Backplate

124: Seat

124a: Load-bearing surface

124b: Bottom surface

128: The Pillar of Severance

140: Switch Module

1401: Connection Port

142: Switch Module Main Body

1421: Slide

1422: Hook

142a: Input Interface

142b: Output Interface

160A: First Phase Bus

160B: Second Phase Bus

164A: Second bus terminal

170: Connection terminal

170a: First end

170b: Second end

H2: Opening

Claims (20)

A power distribution system includes: a frame; at least one bus disposed on the frame and coupled to at least one input line; and a plurality of switching modules, each switching module including a switching module body and a control unit. The switching module body is detachably disposed on the frame and has an input interface and an output interface. The input interface is coupled to the control unit and connected to the at least one bus. The output interface is coupled to the control unit and coupled to the at least one output line. The control unit is disposed within the switching module body and includes a relay and a control circuit board coupled to each other. The power distribution system as described in claim 1, wherein each of the switching modules further includes a shunt and a voltage measurement unit, the shunt and the voltage measurement unit being disposed within the main body of the switching module and coupled to the control circuit board. The power distribution system as described in claim 1 further includes a plurality of connection terminals and a plurality of circuit breakers, wherein the connection terminals are disposed on the frame and respectively correspond to the switching modules, each connection terminal is plugged into the output interface of the corresponding switching module, the circuit breakers are detachably disposed on the frame and respectively connected to the connection terminals, and the output interface is coupled to the at least one output line through the corresponding connection terminal and the corresponding circuit breaker. The power distribution system as described in claim 3, wherein the frame includes a backplate and a base body connected together, the base body having an opposing load-bearing surface and a bottom surface, a receiving space between the backplate and the bottom surface, the switching modules being disposed within the receiving space, and the circuit breakers being disposed on the load-bearing surface. The power distribution system as described in claim 4, wherein the switch module body has two locking holes, the base has multiple openings corresponding to the locking holes of the switch module body, and each switch module further includes two locking attachments, each passing through two corresponding openings to lock onto the corresponding two locking holes of the switch module body, and respectively abutting against the at least one busbar and the corresponding connection terminal. The power distribution system as described in claim 5, wherein each of the circuit breakers is adapted to be detached from the housing to expose portions of the openings. The power distribution system as described in claim 4, wherein the backplane includes a plurality of sub-backplanes that are detachably connected in sequence. The power distribution system as described in claim 4, wherein the base includes a plurality of sub-bases that are detachably connected in sequence. The power distribution system as described in claim 4, wherein the backplate has a plurality of first slide rails, the base has a plurality of second slide rails, and the switch module body has a plurality of grooves, and is slidably disposed between one of the first slide rails and one of the second slide rails via the grooves. The power distribution system as described in claim 4, wherein the main body of the switch module has a latch that engages with the base. The power distribution system as described in claim 10, wherein the base has multiple openings corresponding to the switch modules, and the latch is adapted to be pressed through the corresponding opening to disengage from the base. The power distribution system as described in claim 4, wherein the accommodating space comprises two adjacent sub-accommodating spaces, a portion of the switching modules being arranged sequentially in one sub-accommodating space, and another portion of the switching modules being arranged sequentially in the other sub-accommodating space. The power distribution system as described in claim 12, wherein the at least one bus has a plurality of first bus terminals and a plurality of second bus terminals, the first bus terminals being inserted into the switching modules within one of the sub-accommodating spaces along a first direction, and the second bus terminals being inserted into the switching modules within another of the sub-accommodating spaces along a second direction opposite to the first direction. The power distribution system as described in claim 12 further includes a housing, wherein the dimension of the housing is W in the width direction of the power distribution system, the dimension of each switch module is L, the mounting clearance between each switch module and the housing is a, and the mounting width of the at least one busbar is b, where W = 4*L + 2*a + b < 362 mm. The power distribution system as described in claim 4, wherein each of the connection terminals has opposing first and second ends, the first end being connected to a corresponding circuit breaker, and the second end being connected to a corresponding output interface, each connection terminal passing through the housing such that the housing is positioned between the first and second ends, the second end portion being located within the receiving space, and the at least one busbar disposed on the backplate and positioned between the backplate and the second end. The power distribution system as described in claim 4, wherein the frame further includes multiple support members supported between the back plate and the base, each support member being located between two adjacent switch modules. The power distribution system as described in claim 16, wherein each of the supporting members is an I-beam structure. The power distribution system as described in claim 4, wherein the at least one bus includes a first phase bus and a second phase bus, and the frame further includes at least one insulating post supported between the back plate and the base and spaced between the first phase bus and the second phase bus. The power distribution system as described in claim 3, wherein each of the switching modules is adapted to be independently detached and separated from the other switching modules, the circuit breakers, and the frame. The power distribution system as described in claim 1, wherein the switching modules are coupled to each other via a daisy-chain topology.