Single-phase outgoing line power distribution cabinet capable of realizing inter-phase balance

Abstract

The invention relates to a single-phase outgoing line power distribution cabinet capable of realizing inter-phase balance, which comprises a box body, a voltage collector, a phase selection switch, a UPS (Uninterrupted Power Supply) power supply unit, a phase angle measurer and a control unit, the phase selection switch comprises a shell, a switching bus and a driving assembly, terminals of live wires of all phases are evenly distributed at the position of the shell along the center line, and the driving assembly drives the switching bus to enable the terminals at the position of the switching bus to be communicated with the terminals of the live wires of the corresponding phases. The UPS power supply unit comprises a power supply and an inverter, and the voltage collector, the phase selection switch, the UPS power supply unit and the phase angle measurer are electrically connected with the control unit. The single-phase outgoing line power distribution cabinet capable of realizing inter-phase balance has the beneficial effects of automatically realizing inter-phase switching and uninterruptible power supply.

Description

Technical Field

[0001] The present invention relates to the technical field of distribution cabinets, and particularly to a single-phase outgoing line distribution cabinet capable of achieving phase balance. Background Art

[0002] In the operation and maintenance of low-voltage distribution networks, the unbalance of three-phase loads is a relatively prominent problem. If the three-phase loads of a distribution transformer are unbalanced for a long time, the output currents of each phase will be different, resulting in different three-phase voltage drops inside the distribution transformer, causing unqualified power quality, and at the same time, it will also cause zero-point drift of the distribution transformer.

[0003] Traditional methods for solving three-phase imbalance are as follows: one is to manually cut off the power supply to redistribute the single-phase loads in the areas with serious three-phase loads. However, due to the volatility and non-simultaneity of single-phase loads in the areas, the problem cannot be fundamentally solved; the other is that the reactive power compensation devices in some areas transfer part of the active power by inserting inter-phase capacitors to suppress a small amount of three-phase imbalance problems, but the effect is limited. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a single-phase outgoing line distribution cabinet capable of achieving phase balance, which can automatically realize inter-phase switching and uninterrupted power supply.

[0005] The technical solution of the present invention is as follows:

[0006] A single-phase outgoing line distribution cabinet capable of achieving phase balance includes a cabinet body, and also includes a voltage collector, a phase selection switch, a UPS power supply unit, a phase angle measurer, and a control unit;

[0007] The voltage collector is used to collect the voltage between each phase of the live wire and the neutral wire;

[0008] The phase selection switch includes a housing, a switching busbar, and a driving component. The housing is evenly provided with connection terminals for each phase of the live wire along the center line. The driving component drives the switching busbar so that the connection terminal at the switching busbar is connected to the connection terminal of the corresponding phase of the live wire;

[0009] The UPS power supply unit includes a power supply and an inverter. The inverter is used to convert the power supply into commercial power with the same parameters as any phase, and is used to supply power to the single-phase output terminal of the cabinet body when inter-phase switching occurs;

[0010] The phase angle measurer is respectively used to measure the phase angles of each phase of the live wire and the inverted alternating current;

[0011] The voltage collector, the phase selection switch, the UPS power supply unit, and the phase angle measurer are respectively electrically connected to the control unit.

[0012] Preferably, the driving component is an electromagnet, a ferromagnetic suction block cooperating with the electromagnet is arranged at the switching busbar, and a first spring for making the switching busbar located at the center line position of the housing in the natural state is arranged inside the housing.

[0013] Preferably, a connecting seat is arranged at the switching busbar located inside the phase selection switch. The connecting seat includes a base, a gland, a first joint and a second joint. The first joint is spherical, a groove adapted to the first joint is arranged at the second joint, the second joint is fixedly connected to the base, and the end face of the first joint contacts the second joint through the gland.

[0014] Preferably, a second spring is arranged between the first joint and the gland.

[0015] Preferably, an annular groove for accommodating the second spring is arranged at the end face of the gland facing the first joint.

[0016] Preferably, the housing is of a split type and includes a front housing and a rear housing. A guide seat is clamped between the front housing and the rear housing, and guide grooves are distributed along the center at the guide seat.

[0017] Preferably, a buffer pad is arranged at the position where the base is located at the center and intersects with two adjacent guide grooves.

[0018] Preferably, the housing is of a closed shape, and the internal space of the housing is filled with an insulating gas.

[0019] Preferably, a pressure indicator is arranged on the housing. The pressure indicator includes a guide sleeve, a flexible sealing cover is sleeved on the guide sleeve, a window for observing the position of the flexible sealing cover is arranged on the guide sleeve, one end of the guide sleeve is connected to the housing, the open end of the flexible sealing cover is clamped between the guide sleeve and the housing through the flange where it is located, the other end of the guide sleeve communicates with the outside, and a third spring is arranged between the end of the other end of the guide sleeve communicating with the outside and the flexible sealing cover.

[0020] Preferably, the flexible sealing cover is of a corrugated shape.

[0021] Compared with the prior art, for the single-phase outgoing power distribution cabinet capable of achieving phase balance in the present invention, the phase selection switch and the UPS power supply unit work together. When it is detected that the three-phase load is unbalanced, the control unit can quickly drive the phase selection switch to connect different-phase live wires by switching the busbar, thereby adjusting the load distribution and achieving phase balance. At the same time, during the switching process, the inverter of the UPS power supply unit converts the power into commercial power with the same parameters as any one phase to continuously supply power to the single-phase output end of the cabinet body, ensuring the uninterrupted operation of the electrical equipment. Therefore, it has the beneficial effects of automatically realizing phase switching and uninterrupted power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 FIG. is a schematic diagram of an embodiment of the single-phase outgoing power distribution cabinet capable of achieving phase balance in the present invention.

[0023] Figure 2 FIG. is an exploded view of an embodiment of the phase selection switch of the single-phase outgoing power distribution cabinet capable of achieving phase balance in the present invention.

[0024] Figure 3 FIG. is an exploded view of an embodiment of the connection seat and the switching busbar cooperating with each other of the single-phase outgoing power distribution cabinet capable of achieving phase balance in the present invention.

[0025] Figure 4 FIG. is a schematic cross-sectional view taken along the A-A line after the connection seat of the shown embodiment is assembled.

[0026] Figure 5 FIG. is an exploded view of an embodiment of the pressure indicator and the rear housing cooperating with each other of the single-phase outgoing power distribution cabinet capable of achieving phase balance in the present invention.

[0027] Figure 6 FIG. is a schematic circuit connection diagram of the single-phase outgoing power distribution cabinet capable of achieving phase balance in the present invention.

[0028] Description of the reference numerals in the figures:

[0029] 101 - cabinet body; 102 - wiring terminal; 103 - first spring; 104 - front housing; 105 - electromagnet; 106 - ferromagnetic suction block; 107 - switching busbar; 108 - guide seat; 109 - guide groove; 110 - rear housing; 111 - gland; 112 - first joint; 113 - second joint; 114 - base; 115 - annular groove; 116 - second spring; 117 - flexible sealing cover; 118 - third spring; 119 - guide sleeve; 120 - mounting seat. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] In the description of the present invention, terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In addition, terms such as "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0032] Embodiment 1:

[0033] As Figure 1 shown, the box body 101 is used to install each functional component and at the same time provide basic protection for each functional component. Among them, the box body 101 can be made of stainless steel.

[0034] The voltage collector is used to collect the voltage values between each phase live wire and the neutral wire at the three-phase four-wire incoming line of the box body 101. When in use, the ideal live wire phase can be obtained through the voltage collector. The specific working principle of the voltage collector is as follows: Signal conditioning stage: First, the high voltage is proportionally transformed into a low voltage signal suitable for the control unit to process through a voltage transformer, and then the high-frequency noise is filtered through a filter circuit. Then, the signal is amplified to a suitable amplitude range through an amplifier to adapt to the subsequent analog-to-digital conversion. Analog-to-digital conversion stage: The control unit is built-in or externally connected with an analog-to-digital conversion module (ADC), and samples and quantifies the conditioned analog voltage signal at a certain sampling frequency to convert it into a digital signal. Data processing stage: The control unit processes the converted digital signal, such as calculating the effective value, average value, etc. of the voltage.

[0035] As Figure 1 、 2As shown, a phase selection switch is used to switch the live wire of the outgoing line end of the box body 101 to the ideal live wire position of the incoming line end of the box body 101. Specifically, the phase selection switch includes a housing, a switching busbar 107 and a driving component. For the convenience of installing the internal components of the phase selection switch, the housing is arranged in a split type and includes a front housing 104 and a rear housing 110. The front housing 104 and the rear housing 110 are connected by lugs. Screws are provided at the connection terminals 102 of the three-phase live wires at the incoming line end of the box body 101. Each connection terminal 102 of the three-phase live wires at the incoming line end of the box body 101 is fixedly installed at the end face of the front housing 104 by using nuts through the respective screws. The body of the switching busbar 107 is fixed at the rear housing 110. By using the toughness of the switching busbar 107 itself, the switching busbar 107 is collinear with the center line of the housing in the natural state. One end of the switching busbar 107 is connected with the connection terminal 102 by welding or threading, and the other end of the switching busbar 107 is connected with the live wire of the outgoing line end at the box body 101. The driving component is used to drive the switching busbar 107 so that the connection terminal 102 at the switching busbar 107 can be connected with the connection terminals 102 at each phase of the live wire. To leave a larger travel space for the connection terminal 102 of the switching busbar 107 when it is connected with the live wire connection terminal 102 at the incoming line end of the box body 101, the live wire connection terminals 102 at the incoming line end of the box body 101 are evenly distributed along the center line of the housing.

[0036] An optional form of the driving component is that the driving component adopts the form of electromagnets 105. Three electromagnets 105 are provided, and each electromagnet 105 is arranged on the outer wall of the housing. When each electromagnet 105 is arranged, it should be ensured that they are evenly distributed along the center line of the housing. The relative angles between each electromagnet 105 and the center line of the housing are the same as the angles between the connection terminals 102 of the three-phase live wires and the center line of the housing. Ferromagnetic suction blocks 106 are provided at the switching busbar 107 to cooperate with each electromagnet 105. A first spring 103 is arranged inside the housing to make the switching busbar 107 located at the center line position of the housing in the natural state. Among them, at least three first springs 103 are arranged and evenly distributed along the center line of the housing. Both ends of each first spring 103 are respectively hung on the switching busbar 107 and the lugs on the inner wall of the housing.

[0037] As Figure 1 、 2 As shown, when the switching busbar 107 needs to be switched between the three-phase live wires, the electromagnet 105 on the side of the current-phase live wire is powered off. At this time, under the combined action of the resultant force of each first spring 103, the switching busbar 107 is pulled to the center position, and at this time, the live wire on the outgoing line end side of the box body 101 is in an open circuit state. Then the electromagnet 105 on the side of the live wire to be connected is powered on. By attracting the ferromagnetic suction block 106 at the switching busbar 107, the switching busbar 107 is driven to move towards this phase of the live wire. At this time, the live wire on the outgoing line end side of the box body 101 is connected with the live wire to be connected.

[0038] As Figure 2 , 6 shown, during the process of switching the bus 107 between phases, the UPS power supply continuously supplies power to the outgoing end of the cabinet 101, so that the single-phase output end of the cabinet 101 does not lose power. Specifically, the UPS power supply unit includes a power supply and an inverter, and the inverter is used to convert the power supply into commercial power with the same parameters as any one. Among them, the working principle of the inverter is that the control unit generates a corresponding PWM signal, and simulates the amplitude change of the sine wave by changing the duty cycle of the PWM signal. This signal drives the power switch device in the inverter to make it conduct and turn off according to a specific rule, and converts the DC power supply into a high-frequency pulsed AC signal. Then, the signal passes through the filter circuit to filter out the high-frequency harmonics and obtain an approximate sine alternating current.

[0039] The phase angle measuring device is respectively used to measure the phase angles of the current phase, the phase to be switched, and the inverted alternating current. Among them, the phase angle measuring device can adopt the zero-crossing detection method to measure the phase angle of the phase to be detected.

[0040] As Figure 1 , 2 , 6 shown, the voltage collector, the phase selection switch, the UPS power supply unit, and the phase angle measuring device are respectively electrically connected to the control unit. Specifically, several I / O interfaces are provided at the control unit, and the measuring circuits of the voltage collector and the phase angle measuring device are respectively electrically connected to the corresponding I / O interfaces at the control unit. Each driving component of the phase selection switch is connected in parallel with the power supply through the first relay, and each of the first relays is electrically connected to the corresponding I / O interface at the control unit. The control unit controls each driving component by controlling each first relay. The signal line of the inverter of the UPS power supply unit is electrically connected to the corresponding I / O interface at the control unit. The inverted alternating current is connected in parallel with the outgoing end of the cabinet 101 through the second relay, and the second relay is electrically connected to the corresponding I / O interface at the control unit. The control unit realizes the conduction between the UPS power supply unit and the outgoing end of the cabinet 101 by controlling the opening and closing of the second relay.

[0041] During specific use, the control unit collects the voltage values between each phase live wire and the neutral wire in real time through a voltage collector. When phase - to - phase switching is required, the control unit detects the phase angle of the current phase and the phase angle of the inverted alternating current, and adjusts the PWM signal through the signal line of the inverter until the parameters of the inverted alternating current are consistent with the current phase parameters. The control unit is connected to the output end of the box body 101 through the second relay. At the same time, the control unit opens the drive assembly through the first relay, so that the switching bus 107 is separated from the current phase. The control unit detects the phase angle of the phase to be switched. At the same time, the control unit adjusts the PWM signal through the signal line of the inverter according to the phase angle of the phase to be switched. After the phase angle and frequency of the inverted alternating current are consistent with the phase to be switched, the control unit makes the drive assembly work through the first relay, and the switching bus 107 is connected to the phase to be switched.

[0042] Among them, according to the requirements of the "Technical Management Regulations on Power System Power Quality", to ensure electrical safety, when the switching bus 107 is separated from the current phase and not connected to the phase to be connected, when the control unit adjusts the phase angle of the inverted alternating current, it is advisable to ensure that the frequency deviation does not exceed ±0.2 Hz.

[0043] It can be understood that the functions of the control unit are realized depending on the control unit hardware itself and the program installed in the control unit. It should be noted that the writing of the program is based on the above - mentioned working principle description of the single - phase outgoing power distribution cabinet that can achieve phase - to - phase balance. Among them, when writing the program, the specific assembly language, the called functions, and the data debugging methods, etc. are all existing technologies, and the program installed in the control unit of this application is not the content protected by this solution.

[0044] Among them, the chip of the control unit can use a single - chip microcomputer.

[0045] Embodiment 2:

[0046] On the basis of Embodiment 1, as Figure 3 、 4 shown in the embodiments, to prevent the switching bus 107 from frequently operating and breaking when the phase - selection switch performs phase - to - phase switching. At the same time, to prevent the switching bus 107 from having too much toughness, resulting in too much resistance during phase - to - phase switching. A connecting seat is provided at the switching bus 107 located in the phase - selection switch. Specifically, the connecting seat includes a base 114, a gland 111, a first connector 112, and a second connector 113. To increase the contact area between the first connector 112 and the second connector 113 and prevent the current density from being too large, the first connector 112 is spherical, and a groove adapted to the first connector 112 is provided at the second connector 113.

[0047] The first connector 112 and the second connector 113 are made of the same material with excellent conductivity.

[0048] When assembling the connection base, fix the base 114 to the inner wall of the housing. Fix the second joint 113 to the base 114 through the card slot at the base 114. Connect the gland 111 and the base 114 through the fixing lugs on the side wall. Press the first joint 112 with the gland 111 so that the end face of the first joint 112 contacts the second joint 113. Finally, connect the first joint 112, the second joint 113 and the switching bus 107.

[0049] In this embodiment, as Figure 4 shown, to prevent the gland 111 from applying too much pressing force on the first joint 112, a second spring 116 is provided between the first joint 112 and the gland 111. During use, the two ends of the second spring 116 contact the gland 111 and the first joint 112 respectively. Through the elastic force provided by the second spring 116, the effective contact between the first joint 112 and the second joint 113 is ensured, and at the same time, the excessive friction between the first joint 112 and the second joint 113 during phase switching is prevented.

[0050] In this embodiment, as Figure 4 shown, to prevent the second spring 116 from sliding at the gland 111 during use, a ring groove 115 for accommodating the second spring 116 is provided at the end face of the gland 111 facing the first joint 112.

[0051] Embodiment 3:

[0052] Based on Embodiment 1 or 2, in the embodiment shown as Figure 2 below, when the phase selection switch performs phase switching, to make the switching bus 107 move along a preset trajectory, the housing is of a split type and includes a front housing 104 and a rear housing 110. A guide seat 108 is clamped between the front housing 104 and the rear housing 110. Guide grooves 109 are distributed along the center at the guide seat 108. Among them, the opening angle of the guide grooves 109 is the same as the setting angle of the connection terminals 102 of the three-phase live wires at the incoming line end of the box body 101.

[0053] When performing phase switching, under the action of the driving component or the first spring 103, the switching bus 107 slides along each guide groove 109 to ensure accurate contact with the phase to be switched.

[0054] In this embodiment, to prevent the switching bus 107 from being damaged when it impacts the intersection of two adjacent guide grooves 109 during the process of the first spring 103 pulling the switching bus 107 to the center line position of the housing during phase switching, a buffer pad is provided at the intersection of two adjacent guide grooves 109.

[0055] Embodiment 4:

[0056] On the basis of any one of Embodiments 1-3, to prevent sparks from being generated during phase-to-phase switching and igniting the surrounding combustible gas, the housing is hermetically arranged, and the internal space of the housing is filled with an insulating gas such as sulfur hexafluoride.

[0057] In this embodiment, as Figure 5 shown, to indicate the pressure of the insulating gas in the housing, so as to ensure the presence of the insulating gas in the housing through pressure indication. A pressure indicator is provided at the housing. Specifically, the pressure indicator includes a guide sleeve 119, a flexible sealing cover 117 is sleeved on the guide sleeve 119, a window for observing the position of the flexible sealing cover 117 is provided on the guide sleeve 119, a mounting seat 120 that is in communication with the inside is provided on the outer wall of the housing, one end of the guide sleeve 119 is threadedly connected to the mounting seat 120 on the housing, the open end of the flexible sealing cover 117 is clamped between the guide sleeve 119 and the housing through the flange where it is located, the other end of the guide sleeve 119 is in communication with the outside, and a third spring 118 is provided between the end of the guide sleeve 119 in communication with the outside and the flexible sealing cover 117.

[0058] After the pressure indicator is installed, as the insulating gas in the housing is introduced, the pressure in the housing increases. Under the action of the pressure, one end of the flexible sealing cover 117 moves outward against the third spring 118 until the insulating gas is filled to an appropriate pressure.

[0059] During use, if the housing leaks air, it will inevitably lead to a decrease in the pressure value. At this time, it can be repaired to ensure safety.

[0060] In this embodiment, to enhance the circumferential bearing capacity of the flexible sealing cover 117, the flexible sealing cover 117 is arranged in a corrugated shape.

[0061] The above-described embodiments are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A single-phase outgoing line distribution cabinet capable of achieving phase balance, comprising a box body (101), characterized in that: It also includes a voltage collector, a phase selection switch, a UPS power supply unit, a phase angle measurer and a control unit; The voltage collector is used to collect the voltage between the live wire and the neutral wire of each phase; The phase selection switch comprises a housing, a switching busbar (107) and a driving component, wherein the housing is provided with connection terminals (102) of each phase live wire evenly distributed along a center line, and the driving component drives the switching busbar (107) so that the connection terminals (102) at the switching busbar (107) are connected to the connection terminals (102) of the corresponding phase live wire; The UPS power supply unit comprises a power supply and an inverter, wherein the inverter is used to convert the power supply into a mains power with the same parameters as any other power supply, and is used to supply power to a single-phase output end of the box (101) when switching between phases; The phase angle measuring device is used to measure the phase angle of each phase live wire and the inverter alternating current respectively; The voltage collector, the phase selection switch, the UPS power supply unit, and the phase angle measurer are electrically connected to the control unit respectively.

2. The single-phase outgoing line distribution cabinet capable of achieving phase balance as claimed in claim 1, characterized in that: The driving component is an electromagnet (105), a ferromagnetic suction block (106) cooperating with the electromagnet (105) is arranged at the switching bus (107), and a first spring (103) is arranged inside the shell in a natural state to make the switching bus (107) located at the center line position of the shell.

3. The single-phase outgoing line distribution cabinet capable of achieving phase balance as claimed in claim 1, characterized in that: A connection seat is provided at a switching busbar (107) in a phase selection switch, the connection seat comprising a base (114), a pressure cover (111), a first joint (112) and a second joint (113); the first joint (112) is spherically provided, the second joint (113) is provided with a groove adapted to the first joint (112), the second joint (113) is fixedly connected to the base (114), and the first joint (112) is connected via the pressure cover (111) so that the end surface of the first joint (112) contacts the second joint (113).

4. The single-phase outgoing line distribution cabinet capable of achieving phase balance as claimed in claim 3, characterized in that: A second spring (116) is provided between the first joint (112) and the pressure cover (111).

5. The single-phase outgoing line distribution cabinet capable of achieving phase balance as claimed in claim 4, characterized in that: An annular groove (115) for accommodating a second spring (116) is provided on the end surface of the gland (111) facing the first joint (112).

6. The single-phase outgoing line distribution cabinet capable of achieving phase balance as claimed in claim 3, characterized in that: The housing is arranged in a split type and comprises a front housing (104) and a rear housing (110). A guide seat (108) is clamped between the front housing (104) and the rear housing (110). A guide groove (109) is distributed along the center of the guide seat (108).

7. The single-phase outgoing line distribution cabinet capable of achieving phase balance as claimed in claim 6, characterized in that: A buffer pad is arranged at the center of the base (114) and at the intersection of the base (114) and the two adjacent guide grooves (109).

8. The single-phase outgoing line distribution cabinet capable of achieving phase balance as claimed in claim 1, characterized in that: The shell is arranged in a sealed state, and the inner space of the shell is filled with insulating gas.

9. The single-phase outgoing line distribution cabinet capable of achieving phase balance as claimed in claim 8, characterized in that: The shell is provided with a pressure indicator, which includes a guide sleeve (119), a flexible sealing cover (117) is sleeved on the guide sleeve (119), and a window for observing the position of the flexible sealing cover (117) is provided on the guide sleeve (119). One end of the guide sleeve (119) is connected to the shell, and an open end of the flexible sealing cover (117) is clamped between the guide sleeve (119) and the shell through a flange. The other end of the guide sleeve (119) intersects with the outside world, and a third spring (118) is provided between the end of the guide sleeve (119) intersecting with the outside world and the flexible sealing cover (117).

10. The single-phase outgoing power distribution cabinet capable of achieving phase balance according to claim 9, characterized in that: The flexible sealing cover (117) is arranged in a corrugated shape.

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