A UPS power cabinet for smart grid security defense

Abstract

The application discloses a UPS power cabinet for smart grid security and defense, and relates to the technical field of UPS emergency power cabinets.The UPS power cabinet comprises a UPS emergency power cabinet and a DC busbar connected with a battery pack and an inverter in the UPS emergency power cabinet, and a power buffer assembly is arranged on the side of the DC busbar.The power buffer assembly comprises a cabinet which is installed on the side of the DC busbar in a bypass mode, and the cabinet and the DC busbar do not form a power node in series;the cabinet and all the circuits in the cabinet are not connected to the current path of the DC busbar and are not connected to the DC busbar in series, the cabinet and all the circuits in the cabinet are completely physically isolated from the main power circuit in a normal state, no conduction loss and heat are generated, and the inherent defect that a traditional series compensation module itself becomes a single-point fault source is reduced.

Description

Technical Field

[0001] This invention relates to the field of UPS emergency power supply cabinet technology, specifically a UPS power supply cabinet for smart grid security defense. Background Technology

[0002] In critical infrastructure such as smart grid dispatch centers and substations, UPS emergency power cabinets serve as the last line of defense to ensure the continuous operation of core loads such as dispatch automation master stations, relay protection devices, and communication equipment during mains power outages. When extreme natural disasters or large-scale grid disconnection accidents cause prolonged mains power outages, dispatchers need to rely on battery power to complete critical operations such as grid fault isolation, black start scheme formulation, and remote distribution of protection settings. At this time, the continuity of battery power supply is directly related to whether the grid can avoid evolving from a local fault to a large-scale collapse.

[0003] The UPS emergency power cabinet contains a DC busbar connecting the battery pack and the inverter. The battery pack consists of multiple individual cells connected in series via a rigid copper busbar. Its usable capacity follows the "weakest link" principle, meaning the discharge capacity of the entire battery pack depends on the weakest cell. At the end of a deep discharge, the weakest cell will discharge first, causing its internal resistance to increase sharply and its terminal voltage to drop rapidly. This leads to a sudden drop in the output voltage of the entire battery pack, potentially triggering the inverter's DC undervoltage protection and causing a shutdown, resulting in a blackout in the dispatch system.

[0004] Currently, to address the issue of battery pack voltage dips, existing technologies include connecting a power compensation module in series between the battery pack and the inverter. This primarily uses supercapacitors and DC / DC converters to provide compensation during voltage dips. However, this series-connected compensation scheme has a long-overlooked structural flaw: the power compensation module, connected in series in the main power circuit, becomes a new single point of failure. If a fault occurs within the compensation module, the entire power supply circuit from the battery pack to the inverter will be interrupted. Furthermore, under normal conditions, the series-connected module still receives all load current flowing through its internal components, continuously generating conduction losses and heat, thus reducing the overall system efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a UPS power supply cabinet for smart grid security defense, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a UPS power supply cabinet for smart grid security defense, including a UPS emergency power supply cabinet and a DC busbar connected to a battery pack and an inverter installed inside the UPS emergency power supply cabinet. A power buffer assembly is installed on the side of the DC busbar, and the power buffer assembly includes:

[0008] It has a chassis mounted on the side of the DC bus, and the chassis and the DC bus do not form a power node in series;

[0009] The chassis is divided into three chambers horizontally: a front chamber, a middle chamber, and a rear chamber.

[0010] The rear chamber is equipped with an energy storage battery for storing compensating energy;

[0011] The interior of the middle chamber is equipped with a power switching tube for power conversion, and its input terminal is electrically connected to the energy storage battery.

[0012] A primary magnetic core assembly and a secondary magnetic core assembly, which constitute a separable magnetic coupling structure, wherein the primary magnetic core assembly is installed inside the rear chamber and electrically connected to the output terminal of the power switch tube, and the secondary magnetic core assembly is fixedly installed on the DC busbar, which passes through the window of the secondary magnetic core assembly to serve as a single-turn secondary winding of the separable magnetic coupling structure;

[0013] A drive mechanism, which is connected to the U-shaped high-frequency ferrite core in the primary core assembly, is used to drive the U-shaped high-frequency ferrite core to move between a first position and a second position.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] In this invention, a non-series intrusive side-mounted installation structure is adopted between the power buffer component and the DC bus. The chassis and all internal circuits do not interrupt the DC bus or allow current to enter the DC bus. Under normal conditions, it is completely physically isolated from the main power circuit, generating no conduction losses or heat, thus reducing the inherent defect of traditional series-type compensation modules becoming single-point fault sources. Through a separable magnetic coupling structure composed of primary and secondary magnetic core components, the DC bus itself serves as a single-turn secondary winding of the magnetic coupling transformer. When the voltage drops, the drive mechanism pushes the primary and secondary magnetic core components to fit together, forming a closed magnetic circuit. The compensation energy released by the energy storage battery is injected into the DC bus in a non-contact manner, achieving power compensation without altering the electrical continuity of the original main power circuit. The series connection structure of the secondary windings of the upper and lower magnetic cores allows the DC bias flux in the DC bus to cancel each other out in the series circuit, solving the problem of bias saturation during high-frequency magnetic coupling of a high-current bus. Attached Figure Description

[0016] Figure 1 This is a perspective view of the main structure in this invention;

[0017] Figure 2 In this invention Figure 1 Internal sectional view of the structure;

[0018] Figure 3 This is a schematic diagram of the anterior chamber, middle chamber, and posterior chamber in this invention;

[0019] Figure 4 In this invention Figure 3 Enlarged structural diagram at point A in the middle;

[0020] Figure 5 This is a schematic diagram of the secondary magnetic core assembly in this invention;

[0021] Figure 6 This is a schematic diagram showing the position and structure of the battery pack, inverter, and DC bus in this invention;

[0022] Figure 7 This is a schematic diagram of the installation position of the secondary magnetic core assembly in this invention.

[0023] In the diagram: 100, Power buffer assembly; 110, Front chamber; 111, Auxiliary power module; 112, Control main board; 113, Heat dissipation semiconductor grille; 120, Middle chamber; 121, Power switching transistor; 122, Energy storage inductor; 123, Output filter capacitor; 124, Input filter capacitor; 125, Aluminum-based heat sink; 130, Rear chamber; 131, Energy storage battery; 132, Charging current limiting resistor; 133, Charging... 134. Electrical contactor; 140. Discharge contactor; 141. Primary magnetic core assembly; 143. Drive mechanism; 144. Sliding connecting seat; 145. U-shaped high-frequency ferrite core; 156. Secondary magnetic core assembly; 157. Upper magnetic core; 158. Lower magnetic core; 159. Upper arm; 150. Lower arm; 151. Window; 152. Positioning hole; 153. DC bias flux; 200. Guide rail groove; 210. L-shaped cross-section slide rail. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] To address the problems identified in the background section of the prior art, this invention discloses a UPS power supply cabinet for smart grid security defense, comprising a UPS emergency power supply cabinet and a DC busbar connecting the battery pack and the inverter installed within the cabinet. A power buffer component 100 is installed on the side of the DC busbar. Due to these features, when the voltage of the battery pack experiences a sudden drop due to individual cell failure, the invention can inject compensation power into the DC busbar non-contactly via a non-series intrusive bypass structure of the power buffer component 100 and the DC busbar using a separable magnetic coupling method. This maintains a constant inverter input voltage without altering the electrical continuity of the original main power circuit or introducing new series fault points, ensuring uninterrupted power supply to the core loads.

[0026] The following describes in detail the specific implementation methods for achieving the above-mentioned technical features and the further effects they can produce.

[0027] In one specific implementation, such as Figures 1 to 7 As shown, the power buffer assembly 100 includes: a chassis mounted sideways on the side of a DC bus, wherein the chassis and the DC bus do not form a series power node; the interior of the chassis is divided into three chambers horizontally, namely a front chamber 110, a middle chamber 120, and a rear chamber 130; a storage battery 131 is installed inside the rear chamber 130 for storing compensation energy; a power switch 121 for power conversion is installed inside the middle chamber 120, and its input terminal is electrically connected to the storage battery 131; a primary magnetic core assembly 140 and a secondary magnetic core assembly 150. The primary magnetic core assembly 140 and the secondary magnetic core assembly 150 constitute a separable magnetic coupling structure. The primary magnetic core assembly 140 is installed inside the rear chamber 130 and electrically connected to the output terminal of the power switch tube 121. The secondary magnetic core assembly 150 is fixedly installed on the DC bus. The DC bus passes through the window of the secondary magnetic core assembly 150 to serve as a single-turn secondary winding of the separable magnetic coupling structure. The drive mechanism 141 is connected to the U-shaped high-frequency ferrite core 144 in the primary magnetic core assembly 140 and is used to drive the U-shaped high-frequency ferrite core 144 to move between a first position and a second position.

[0028] Specifically, the overall architecture of the power buffer assembly 100 adopts a non-series intrusive design. The chassis is mounted side-mounted on the side of the DC bus, arranged parallel to the DC bus. The side-mounted method means that the chassis and the DC bus do not form a series power node; that is, the chassis and all its internal circuits do not interrupt the DC bus or introduce current into the DC bus. The DC bus remains a continuous, integrated copper bus structure, with no electrical breaks in the mounting area of ​​the power buffer assembly 100, whether plugged in or bolted. This side-mounted installation method ensures that the power buffer assembly 100 is completely physically isolated from the main power circuit under normal conditions, generating no conduction losses or heat, and not increasing the risk of failure in the main circuit. This reduces the problem of traditional series-type compensation modules becoming single points of failure.

[0029] The chassis is horizontally divided into a front chamber 110, a middle chamber 120, and a rear chamber 130 from front to back. The front chamber 110, located near the front panel, houses the control circuitry and auxiliary power supply. The middle chamber 120, situated in the central area, houses the power conversion circuitry. The rear chamber 130, located near the rear panel and facing the DC bus, houses the energy storage devices and the primary side of the magnetic coupling unit. The three chambers are separated by metal partitions, achieving both functional zoning and electromagnetic shielding to prevent high-frequency electromagnetic interference from the power conversion circuitry from affecting the control circuitry. The energy storage battery 131 pre-stores compensation energy under normal conditions and releases energy for power conversion during voltage dips. The power switch 121 and its surrounding circuitry constitute the power conversion unit, responsible for converting the DC energy released from the energy storage battery 131 into high-frequency AC power suitable for magnetic coupling transmission. The primary magnetic core assembly 140 and the secondary magnetic core assembly 150 together form a separable magnetic coupling structure.

[0030] It should be noted that, for example, 6 and Figure 7 As shown, M is the front-end battery pack, K is the middle DC bus, P is the end inverter, and T is the UPS emergency power cabinet, which is the overall structure installed inside the UPS emergency power cabinet. Following the power flow direction, the front-end battery pack, the middle DC bus, and the end inverter are connected sequentially to form the main power supply circuit.

[0031] The battery pack consists of multiple individual batteries connected in series via rigid copper busbars and is installed at the bottom of the UPS emergency power supply cabinet. The inverter is installed at the top of the UPS emergency power supply cabinet, with its positive and negative DC input terminals connected to the DC busbars respectively. The inverter's output terminals are connected to the output distribution unit via AC busbars, and the output distribution unit then distributes power to each load branch.

[0032] The DC busbar includes a positive busbar and a negative busbar, arranged side by side and separated by an insulating partition. Both busbars are made of silver-plated copper with a rectangular cross-section, the dimensions of which are determined according to the rated power of the UPS. The DC busbar extends vertically along the UPS emergency power cabinet, passing through the battery pack compartment at the bottom, through the power buffer assembly 100 installation area in the middle, and extending to the inverter input port at the top.

[0033] It should be noted that the chassis material used in this solution can be any one of aluminum alloy, stainless steel, galvanized steel sheet or engineering plastic.

[0034] like Figure 7 As shown, the narrow front face of the DC busbar is K3, and the wide rear face is K4. The front-to-back direction of the cabinet is defined as the X-axis, the left-to-right direction as the Y-axis, and the vertical direction as the Z-axis. The wide face of the DC busbar faces the Y-axis direction, i.e., the left and right sides of the UPS emergency power supply cabinet, while the narrow face, i.e., the thicker side, faces the X-axis direction, i.e., the front-to-back direction of the UPS emergency power supply cabinet.

[0035] The DC busbar has an integrated structure with no breaks in the middle, whether plugged in or bolted, ensuring that the electrical continuity of the main power circuit is not affected by any external equipment connection.

[0036] Furthermore, the upper end K1 of the positive busbar is fixedly connected to the copper busbar interface of the inverter's DC input positive terminal P1 by bolts, and the upper end K2 of the negative busbar is fixedly connected to the copper busbar interface of the inverter's DC input negative terminal P2 by bolts. The inverter output is connected to the output power distribution unit via an AC busbar, and the output power distribution unit then distributes the power to each load branch.

[0037] In this solution, the power buffer component 100 is not connected in series to the main power circuit. Instead, it is mounted on the side of the DC busbar in the form of an independent drawer-type chassis, forming a non-intrusive structure in parallel with the main circuit.

[0038] In one specific implementation, such as Figures 1 to 7 As shown, in the first position, the primary magnetic core assembly 140 and the secondary magnetic core assembly 150 are separated, the magnetic circuit is broken, and there is no power transmission between the power buffer assembly 100 and the DC bus. In the second position, the primary magnetic core assembly 140 and the secondary magnetic core assembly 150 are bonded together to form a closed magnetic circuit. The power buffer assembly 100 converts the energy released by the energy storage battery 131 and injects it into the DC bus non-contactly through the separable magnetic coupling structure to compensate for the voltage drop of the DC bus.

[0039] Specifically, the first position corresponds to the normal standby state. In this state, the primary magnetic core assembly 140 is retracted into the chassis, and a significant air gap is maintained between the mating surface of its U-shaped high-frequency ferrite core 144 and the mating surface of the secondary magnetic core assembly 150. Since the permeability of air is much lower than that of the ferrite core material, this air gap completely disconnects the magnetic circuit. Even if the power switch 121 unexpectedly operates and outputs a high-frequency current to the primary winding, the generated magnetic flux cannot effectively couple to the secondary magnetic core assembly 150 across this gap. Therefore, in the first position, there is no electrical or electromagnetic coupling between the power buffer assembly 100 and the DC bus. The battery discharge current carried on the DC bus flows normally and is not affected by the power buffer assembly 100. The energy storage battery 131 is in a fully charged standby state, the power switch 121 is not operating, and the entire power buffer assembly 100 is in a zero-power cold backup state.

[0040] The second position corresponds to the voltage drop compensation state. When the control motherboard 112 detects an abnormal drop in the DC bus voltage, it issues a compensation start command. The drive mechanism 141 drives the primary magnetic core assembly 140 to extend from inside the chassis, and the first contact surface of the U-shaped high-frequency ferrite core 144 is tightly attached to the second contact surface of the secondary magnetic core assembly 150, closing the magnetic circuit. At the same time, the energy storage battery 131 begins to release energy, and the power switch 121 performs high-frequency switching, converting DC energy into high-frequency AC power and delivering it to the primary winding. The high-frequency alternating magnetic flux is conducted along the closed magnetic circuit, inducing a compensation voltage on the DC bus, which is a single-turn secondary winding. This compensation voltage is superimposed on the current output voltage of the battery pack, jointly maintaining the stability of the inverter input voltage.

[0041] In one specific implementation, such as Figure 5 As shown, the secondary core assembly 150 includes an upper core 151 and a lower core 152. The upper core 151 and the lower core 152 are respectively clamped and installed on the upper and lower sides of the DC bus. The DC bus passes through the window 155 formed by the upper core 151 and the lower core 152. Secondary windings are wound on the upper core 151 and the lower core 152 respectively. The two secondary windings are connected in series, and the series direction is such that the DC bias flux 157 generated by the DC current in the DC bus in the upper core 151 and the lower core 152 cancels each other out in the series circuit.

[0042] Specifically, the secondary core assembly 150 adopts a symmetrical dual-core clamping structure. Both the upper core 151 and the lower core 152 are toroidal high-frequency ferrite cores, and their inner windows together form window 155, through which the DC bus passes. The installation of the secondary core assembly 150 can be completed without any processing or modification to the DC bus, making it suitable for non-stop retrofitting of existing UPS power cabinets.

[0043] Furthermore, because the direction of the DC operating current in the DC busbar is unique, this current generates a DC bias flux in one direction within the window of the upper magnetic core 151, and similarly in the window of the lower magnetic core 152. However, since the upper magnetic core 151 and the lower magnetic core 152 are spatially located on the upper and lower sides of the busbar, respectively, and their spatial orientations relative to the busbar are different, the DC bias flux induced by the busbar current in the same direction in the two magnetic cores circulates in opposite directions in the magnetic circuit. When the two secondary windings are connected in series in a specific direction, the DC voltage components induced by these two approximately equal but opposite DC bias fluxes in the series circuit cancel each other out. Therefore, regardless of the magnitude of the DC operating current flowing in the busbar, no DC bias saturation effect will occur in the magnetically coupled transformer, ensuring that the separable magnetic coupling structure can still operate stably under full-load or even overload DC bias conditions on the busbar, without coupling failure caused by magnetic core saturation.

[0044] It should be noted that, in the actual manufacturing process, to ensure the parameter symmetry of the two magnetic cores, a pairing screening method can be adopted: from the same batch of high-frequency ferrite magnetic cores, two magnetic cores with inductance deviations within a preset range and similar temperature coefficients of permeability are selected for pairing. Simultaneously, during the installation of the secondary magnetic core assembly, the clamping positions of the upper magnetic core 151 and the lower magnetic core 152 relative to the busbar can be finely adjusted by adjusting the fine-tuning screws on the insulating clamping bracket, ensuring that the window centers of the two magnetic cores are precisely aligned with the geometric center of the busbar, maximizing the symmetrical cancellation effect of the DC bias flux.

[0045] In one specific implementation, such as Figure 4 and Figure 5 As shown, a primary winding is wound on a U-shaped high-frequency ferrite core 144. The two arm ends of the U-shaped high-frequency ferrite core 144 are first contact surfaces. The upper core 151 and the lower core 152 are each provided with a second contact surface on the side facing the primary core assembly 140. In the second position, the two first contact surfaces are tightly contacted with the two second contact surfaces respectively. The U-shaped high-frequency ferrite core 144, the upper core 151 and the lower core 152 together form a closed magnetic circuit. A positioning pin is provided on the first contact surface, and a positioning hole 156 that cooperates with the positioning pin is provided on the second contact surface to ensure the precise alignment of the first contact surface and the second contact surface in the second position. The connecting ends of the upper core 151 and the lower core 152 are respectively provided with an upper arm 153 and a lower arm 154.

[0046] Specifically, the U-shaped high-frequency ferrite core 144, together with the upper core 151 and the lower core 152, constitutes a three-piece separable magnetically coupled transformer. The U-shaped high-frequency ferrite core 144 serves as the primary-side core of the transformer, with multiple turns of primary winding wound on it. The primary winding uses multi-strand stranded high-frequency Litz wire to reduce skin effect losses at high frequencies. The upper core 151 and the lower core 152 serve as the secondary-side cores of the transformer, with a DC busbar passing through the window 155 between them as a single-turn secondary winding. When in the second position, the first contact surfaces of the two arms of the U-shaped high-frequency ferrite core 144 are tightly contacted with the second contact surfaces of the upper core 151 and the lower core 152, respectively, closing the magnetic circuit. This allows the alternating magnetic flux to be conducted along the closed loop from the U-shaped high-frequency ferrite core 144, the upper core 151, the window 155, the lower core 152 back to the U-shaped high-frequency ferrite core 144.

[0047] The first mating surface is provided with a tapered positioning pin, and the second mating surface is provided with a tapered positioning hole 156 that precisely matches the positioning pin. As the primary magnetic core assembly 140 moves from the first position to the second position, the positioning pin first enters the guide tapered surface of the positioning hole 156. As the drive mechanism 141 continues to advance, the tapered surface automatically corrects minor positional deviations, ultimately achieving precise alignment of the two mating surfaces.

[0048] Furthermore, depending on the actual situation, an extremely thin layer of magnetically conductive silicone grease can be applied to the bonding surface to fill any remaining microscopic unevenness after mirror polishing, further reducing the equivalent air gap and maximizing magnetic coupling efficiency. The upper arm 153 extends from the body of the upper magnetic core 151 towards the primary magnetic core assembly 140, and the lower arm 154 extends from the body of the lower magnetic core 152 towards the primary magnetic core assembly 140. The arrangement of the upper arm 153 and lower arm 154 increases the cross-sectional area of ​​the magnetic circuit, reduces magnetic resistance, and provides sufficient space for the second bonding surface and the positioning hole 156.

[0049] In one specific implementation, such as Figure 4 As shown, a sliding connecting seat 143 is installed at the connection end of the drive mechanism 141 and the U-shaped high-frequency ferrite core 144. The drive mechanism 141 drives the primary core assembly 140 to move linearly between the first position and the second position by driving the sliding connecting seat 143. A high conductivity metal foil layer is applied to the surface of a local area on the DC bus that is clamped by the secondary core assembly 150. The thickness of the metal foil layer is one to two times the skin depth of the current at the output frequency of the power switch tube 121. It is used to constrain the high-frequency induced current and reduce eddy current loss. The drive mechanism 141 is installed on the bottom plate of the rear chamber 130. The direction of movement of the drive mechanism 141 is perpendicular to the plane direction of the DC bus.

[0050] Specifically, the drive mechanism 141 adopts a linear slide structure, consisting of a guide rail, a slider, a lead screw, and a motor. The guide rail is fixedly mounted on the base plate of the rear chamber 130 along a direction perpendicular to the DC bus plane. The slider engages with the lead screw via a lead screw nut, and the motor is connected to one end of the lead screw via a coupling. A sliding connecting seat 143 is fixedly mounted on the slider, and the bottom of the U-shaped high-frequency ferrite core 144 is fixed to the sliding connecting seat 143 via an insulating clamp in the sliding connecting seat 143. When the motor rotates forward, the lead screw drives the slider to move along the guide rail towards the DC bus, causing the primary core assembly 140 to move from the first position to the second position; when the motor rotates in the reverse direction, the slider moves away from the DC bus, causing the primary core assembly 140 to move from the second position back to the first position.

[0051] A high-conductivity metal foil layer is applied to a localized area on the DC busbar surface held by the secondary magnetic core assembly 150. This metal foil layer is made of silver-plated copper foil and is integrated with the busbar body through a low-temperature diffusion welding process to form a conductive structure. Its thickness is designed to match the skin depth of the current at the output frequency of the power switch 121, effectively confining the high-frequency induced current within this high-conductivity thin layer. This avoids the high equivalent resistance and eddy current losses caused by the skin effect when the high-frequency current flows deeper within the busbar body, significantly improving the magnetic coupling power transmission efficiency. Furthermore, the metal foil layer is only applied locally in the core-holding area, without affecting the overall DC high-current carrying capacity of the busbar.

[0052] It should be noted that the drive mechanism 141 used in this solution, in addition to the linear slide structure in which the motor drives the lead screw and nut pair to drive the slider to move linearly as described in the preferred embodiment above, can also adopt any of the following structures that can achieve linear reciprocating motion.

[0053] To ensure a stable and reliable fit between the primary magnetic core assembly 140 and the secondary magnetic core assembly 150 in the second position, an anti-loosening locking structure is further provided in the drive mechanism 141. This anti-loosening locking structure includes an electromagnetic locking pin and a corresponding locking hole. The electromagnetic locking pin is installed inside the rear panel of the chassis, and the locking hole is located at the corresponding position of the sliding connector. When the drive mechanism 141 pushes the primary magnetic core assembly 140 to the second position, the control motherboard 112 energizes the coil of the electromagnetic locking pin. The locking pin extends and inserts into the locking hole of the sliding connector, locking the sliding connector 143 and the primary magnetic core assembly 140 in the second position. Even if the motor is de-energized, the primary magnetic core assembly 140 will not loosen due to vibration or external force. When compensation is complete and retraction is required, the control motherboard 112 first de-energizes the coil of the electromagnetic locking pin. The locking pin retracts under the action of the return spring, and then the motor rotates in the opposite direction to pull the primary magnetic core assembly 140 back to the first position. The anti-loosening locking structure ensures the reliability of the magnetic core fit and prevents magnetic circuit breakage and arcing caused by accidental loosening during power transmission.

[0054] In addition, a flexible dustproof sealing ring is provided around the rectangular window on the rear panel of the chassis. This sealing ring is made of silicone rubber or fluororubber and fits in a ring shape against the inner edge of the window. When the drive mechanism 141 pushes out the primary magnetic core assembly 140, the arm end of the U-shaped high-frequency ferrite core 144 passes through the sealing ring, and the sealing ring fits tightly against the outer wall of the U-shaped high-frequency ferrite core 144, preventing external dust and moisture from entering the chassis through the window 155. When the drive mechanism 141 retracts the primary magnetic core assembly 140 into the chassis, the window 155 is closed by a spring-loaded dustproof baffle that automatically returns to its original position. The dustproof baffle is hinged to the upper edge of the window, and a return spring is provided on one side inside the chassis. Under normal conditions, the dustproof baffle remains closed under the action of the spring force, further ensuring the cleanliness of the chassis interior.

[0055] In one specific implementation, such as Figure 3 As shown, the front chamber 110 is close to the front panel. The control main board 112 and the auxiliary power module 111 are installed inside the front chamber 110. The control main board 112 is fixed to the bottom plate of the front chamber 110 by copper pillars. The auxiliary power module 111 is fixed to the side of the control main board 112 by screws. The front panel of the front chamber 110 has a heat dissipation semiconductor grille 113.

[0056] Specifically, the control motherboard 112 uses an embedded processor to be responsible for the acquisition and processing of voltage signals, real-time analysis of voltage change rate, motion control of drive mechanism 141, pulse width modulation control of power switch 121, and on / off control of charging contactor 133 and discharging contactor 134.

[0057] The control motherboard 112 is mounted on the base plate of the front chamber 110 via copper pillars. These pillars provide mechanical support and maintain an air gap between the control motherboard 112 and the base plate, facilitating heat dissipation and preventing direct heat transfer from the base plate to the circuit board. The auxiliary power module 111 converts the input voltage from the AC bus or independent auxiliary power supply within the UPS cabinet into multiple isolated DC output voltages, supplying power to the control motherboard 112, the motor driver of the drive mechanism 141, the coil of the charging contactor 133, the coil of the discharging contactor 134, and the drive circuit of the power switching transistor 121. The input of the auxiliary power module 111 is equipped with a fuse and an electromagnetic interference filter circuit to ensure power supply safety and electromagnetic compatibility. A heat dissipation semiconductor grille 113 on the front panel of the front chamber 110 forms a natural convection airflow channel. External cool air enters from the bottom of the grille, absorbs heat from inside the front chamber 110, and is then exhausted from the top of the grille, providing effective heat dissipation for the control motherboard 112 and the auxiliary power module 111.

[0058] In one specific implementation, such as Figure 3As shown, the power switch 121 is mounted on an aluminum-based heat sink 125 in the middle chamber 120. The bottom of the aluminum-based heat sink 125 is attached to the bottom plate of the middle chamber 120 with thermal grease, and heat dissipation is carried out by the bottom plate of the middle chamber 120. An energy storage inductor 122 is mounted on the side of the power switch 121 by a bracket. The energy storage inductor 122 is a toroidal magnetic core inductor. An input filter capacitor 124 and an output filter capacitor 123 are arranged at the front and rear ends of the power switch 121, respectively.

[0059] Specifically, the power switching transistor 121 in the intermediate chamber 120 is the main structure for power conversion and generates significant heat during high-frequency switching. The aluminum-based heat sink 125, with its high thermal conductivity, rapidly diffuses the heat generated by the power switching transistor 121 laterally, and then conducts it to the bottom plate of the intermediate chamber 120 via the thermally conductive silicone grease layer. The bottom plate of the intermediate chamber 120, which serves as the chassis base plate, is made of aluminum alloy or stainless steel and has a large heat dissipation area. Utilizing the entire chassis shell as the heat dissipation surface eliminates the need for an additional cooling fan, reducing power consumption and noise, and improving the reliability of the device.

[0060] The energy storage inductor 122 is a toroidal core inductor, a key passive component in the power conversion stage that stores and transfers magnetic field energy. The toroidal core inductor uses high-frequency, low-loss ferrite or amorphous nanocrystalline materials, and the winding is made of multi-strand Litz wire to reduce high-frequency copper losses. The energy storage inductor 122 is fixed to the side of the power switch 121 by an insulating bracket, minimizing the length of the connection line between it and the power switch 121 to reduce parasitic inductance and improve switching waveform quality.

[0061] The input filter capacitor 124 is located on the side of the power switch 121 used for power conversion near the rear chamber 130. It is used to smooth the DC voltage released by the energy storage battery 131 and filter out the ripple current in the discharge circuit. The output filter capacitor 123 is located on the side of the power conversion unit near the front chamber 110. It is used to smooth the high-frequency AC voltage output by the power switch 121, filter out the switching frequency and its harmonic components, and provide stable high-frequency AC power for the primary core assembly 140. Both the input filter capacitor 124 and the output filter capacitor 123 are metal film capacitors with low equivalent series resistance to reduce heat generation under high-frequency ripple.

[0062] In one specific implementation, such as Figure 3As shown, the energy storage battery 131 is composed of multiple cylindrical supercapacitor cells connected in series. Each cylindrical supercapacitor cell is connected in series via nickel strips or copper braided strips. The positive terminal of the first cell leads out a positive bus, and the negative terminal of the last cell leads out a negative bus. The positive bus of the cylindrical supercapacitor cells is connected to the positive terminal of the DC bus inside the module through the normally open contact of the charging contactor 133, and the negative bus is directly connected to the negative terminal of the internal DC bus. The coil of the charging contactor 133 is electrically connected to the charging control output terminal of the control main board 112. A charging current limiting resistor 132 is connected in series between the charging contactor 133 and the internal DC bus to limit the charging current. The positive bus of the cylindrical supercapacitor cells is connected to the positive input terminal of the power switch tube 121 through the normally open contact of the discharge contactor 134, and the negative bus is directly connected to the negative input terminal of the power switch tube 121. The coil of the discharge contactor 134 is electrically connected to the discharge control output terminal of the control main board 112. A reverse protection diode is connected in series between the discharge contactor 134 and the power switch 121 to prevent reverse current flow.

[0063] In other words, the energy storage battery 131 actually uses a supercapacitor module rather than a chemical battery. Supercapacitors have the characteristics of high power density, fast charging and discharging speed, extremely long cycle life, and maintenance-free operation. They can release large currents in a short time, making them extremely suitable as an energy source for voltage drop transient compensation. Multiple cylindrical supercapacitor cells are connected in series by nickel sheets or copper braided strips. The nickel sheets or copper braided strips are directly spot-welded or laser-welded to the end face of the cells, resulting in low contact resistance and reliable connection. A voltage equalization resistor is connected in parallel across each cell, and the voltage equalization resistor is directly welded to the series connection piece to ensure that the voltage of each cell remains consistent during charging, preventing overcharging or undercharging due to differences in cell parameters.

[0064] The energy management of the supercapacitor module is achieved through two independent electrical paths: a charging circuit and a discharging circuit. In normal standby mode, the normally open contact of the charging contactor 133 is closed, and the auxiliary power module 111 performs trickle charging of the supercapacitor module through the charging current-limiting resistor 132. The charging current-limiting resistor 132 limits the charging current amplitude to prevent damage to the supercapacitor from large current surges. The supercapacitor module remains in a fully charged standby state. At this time, the normally open contact of the discharging contactor 134 remains open, and the supercapacitor module is electrically isolated from the input terminal of the power switch 121. When compensation is required, the control motherboard 112 sends a closing command to the coil of the discharging contactor 134, causing the normally open contact of the discharging contactor 134 to close. The supercapacitor module is then connected to the input terminal of the power switch 121 and begins to release energy. The anti-reverse diode is connected in series between the discharge contactor 134 and the power switch 121, with its anode facing the supercapacitor module side and its cathode facing the power switch 121 side, to prevent current from flowing back from the power switch 121 to the supercapacitor module and to protect the supercapacitor from reverse charging damage.

[0065] In one specific implementation, such as Figure 1 and Figure 2 As shown, each side of the base plate of the power buffer assembly 100 is provided with an L-shaped section slide rail 210. The L-shaped section slide rail 210 is fixed to the base plate of the chassis by screws. Inside the UPS emergency power cabinet, there is a guide rail groove 200 that cooperates with the L-shaped section slide rail 210. The guide rail groove 200 is fixedly installed on the mounting beam on the side wall of the UPS emergency power cabinet.

[0066] Specifically, the power buffer assembly 100 adopts a drawer-type pluggable installation structure. The L-shaped cross-section slide rail 210 is arranged along the longitudinal direction of the chassis, and its L-shaped cross-section provides high bending stiffness and guiding accuracy. The guide rail groove 200 is fixedly installed on the mounting beam on the inner side wall of the UPS emergency power cabinet. The mounting beam is part of the cabinet's structural frame and has sufficient load-bearing capacity. During installation, the L-shaped cross-section slide rails 210 on both sides of the chassis are aligned with the entrance of the guide rail groove 200 and pushed in. The L-shaped cross-section slide rails 210 slide and guide within the guide rail groove 200. After being pushed into place, they are locked and fixed to the front cross beam of the cabinet by the locking screws on the front panel to prevent loosening during transportation and operation. For disassembly, loosening the locking screws allows the entire power buffer assembly 100 to be pulled out of the cabinet via the L-shaped cross-section slide rail 210 for offline inspection or replacement. Since the power buffer component 100 and the DC busbar do not form a series power node, the DC busbar always maintains electrical continuity during installation and disassembly, and the UPS emergency power cabinet can continue to operate without being affected, realizing true online non-stop installation and maintenance.

[0067] In another implementation, such as Figure 2 As shown, the DC busbar is electrically connected to a voltage sampling circuit at its input end. The output end of the voltage sampling circuit is electrically connected to the control main board 112 to detect the voltage change rate of the DC busbar in real time. The DC busbar is an integral continuous copper busbar with no electrical breaks in the installation area of ​​the power buffer assembly 100, whether plugged or bolted.

[0068] It should be noted that the voltage sampling circuit is the key front-end circuit for voltage drop detection. Its input is connected to a sampling point on the DC busbar near the inverter input via a fuse to reflect the actual voltage received by the inverter as accurately as possible. The fuse provides overcurrent protection to prevent short circuits in the sampling line from affecting the busbar. Internally, the voltage sampling circuit includes a resistor divider network and an isolation operational amplifier. The resistor divider network proportionally reduces the high voltage on the busbar to a voltage range suitable for the analog-to-digital converter input. The isolation operational amplifier provides electrical isolation to prevent high voltage or transient interference on the busbar from being conducted to the control board 112. The divided analog voltage signal is sent to the analog-to-digital converter input interface of the control board 112 via a shielded signal line. The control board 112 continuously calculates the sampled voltage using a built-in voltage change rate detection algorithm, monitoring the rate of change of the busbar voltage in real time. When the voltage drop rate exceeds a preset threshold, it is determined to be an abnormal voltage drop event in the battery pack, and a compensation program is initiated. Using the rate of change of voltage instead of the absolute value of voltage as the trigger criterion can effectively distinguish between normal load fluctuations and abnormal drops caused by battery failure, thus avoiding false triggering.

[0069] It should be noted that during the magnetic coupling power injection process, the alternating magnetic flux is mainly concentrated in the closed magnetic circuit formed by the U-shaped high-frequency ferrite core 144, the upper core 151, the window 155, and the lower core 152. However, since the actual magnetic circuit cannot achieve an ideal complete closure, a small portion of leakage magnetic flux will still pass through the space around the busbar, inducing eddy currents in the metal components near the busbar. To avoid heating of adjacent metal components caused by leakage magnetic flux, the following protective measures are taken on the cabinet structural components around the installation area of ​​the secondary core assembly 150: First, the busbar mounting beam and cabinet sidewalls in the magnetic coupling area are made of non-magnetic stainless steel or aluminum alloy to reduce hysteresis loss and eddy current loss; Second, an aluminum foil or copper foil electromagnetic shielding layer is set between the secondary core assembly 150 and the adjacent metal components. The shielding layer is grounded to effectively absorb and reflect the leakage magnetic field, reducing the induced influence on surrounding components; Third, the edges of the metal components in the magnetic coupling area are rounded to avoid local electric field concentration and discharge caused by the sharp point effect. The above measures can be used to jointly ensure the temperature stability and electrical safety of the cabinet structure during power injection.

[0070] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A UPS power supply cabinet for smart grid security defense, comprising a UPS emergency power supply cabinet and a DC busbar connected to a battery pack and an inverter installed inside the UPS emergency power supply cabinet, wherein a power buffer assembly (100) is installed on the side of the DC busbar, characterized in that, The power buffer assembly (100) includes: It has a chassis mounted on the side of the DC bus, and the chassis and the DC bus do not form a power node in series; The chassis is divided into three chambers along the horizontal direction: a front chamber (110), a middle chamber (120), and a rear chamber (130). The rear chamber (130) is equipped with an energy storage battery (131) for storing compensation energy; The interior of the middle chamber (120) is equipped with a power switching tube (121) for power conversion, and its input terminal is electrically connected to the energy storage battery (131); A primary magnetic core assembly (140) and a secondary magnetic core assembly (150) are provided, which together form a separable magnetic coupling structure. The primary magnetic core assembly (140) is installed inside the rear chamber (130) and electrically connected to the output terminal of the power switch tube (121). The secondary magnetic core assembly (150) is fixedly installed on a DC busbar, which passes through the window of the secondary magnetic core assembly (150) to serve as a single-turn secondary winding of the separable magnetic coupling structure. A drive mechanism (141), which is connected to a U-shaped high-frequency ferrite core (144) in a primary core assembly (140), is used to drive the U-shaped high-frequency ferrite core (144) to move between a first position and a second position.

2. The UPS power supply cabinet for smart grid security defense according to claim 1, characterized in that: In the first position, the primary magnetic core assembly (140) and the secondary magnetic core assembly (150) are separated, the magnetic circuit is broken, and there is no power transmission between the power buffer assembly (100) and the DC bus. In the second position, the primary magnetic core assembly (140) and the secondary magnetic core assembly (150) are bonded together to form a closed magnetic circuit. The power buffer assembly (100) converts the energy released by the energy storage battery (131) and injects it into the DC bus non-contactly through a separable magnetic coupling structure to compensate for the voltage drop of the DC bus.

3. The UPS power supply cabinet for smart grid security defense according to claim 1, characterized in that: The secondary magnetic core assembly (150) includes an upper magnetic core (151) and a lower magnetic core (152), which are respectively clamped and installed on the upper and lower sides of the DC bus. The DC bus passes through the window (155) formed by the upper magnetic core (151) and the lower magnetic core (152). Secondary windings are wound on the upper magnetic core (151) and the lower magnetic core (152), respectively. The two secondary windings are connected in series, and the series direction is such that the DC bias flux (157) generated by the DC current in the DC busbar in the upper magnetic core (151) and the lower magnetic core (152) cancel each other out in the series circuit.

4. The UPS power supply cabinet for smart grid security defense according to claim 1, characterized in that: The U-shaped high-frequency ferrite core (144) is wound with a primary winding. The two arm ends of the U-shaped high-frequency ferrite core (144) are first contact surfaces. The upper core (151) and the lower core (152) are each provided with a second contact surface on the side facing the primary core assembly (140). In the second position, the two first contact surfaces are tightly attached to the two second contact surfaces respectively. The U-shaped high-frequency ferrite core (144), the upper core (151) and the lower core (152) together form a closed magnetic circuit. The first contact surface is provided with a positioning pin. The second contact surface is provided with a positioning hole (156) that cooperates with the positioning pin, which is used to ensure the precise alignment of the first contact surface and the second contact surface in the second position. The connecting ends of the upper core (151) and the lower core (152) are respectively provided with an upper arm (153) and a lower arm (154).

5. The UPS power supply cabinet for smart grid security defense according to claim 1, characterized in that: The drive mechanism (141) and the U-shaped high-frequency ferrite core (144) are connected by a sliding connection seat (143). The drive mechanism (141) drives the primary core assembly (140) to move linearly between the first position and the second position by driving the sliding connection seat (143). A high conductivity metal foil layer is applied to the surface of the local area on the DC bus held by the secondary core assembly (150). The thickness of the metal foil layer is one to two times the skin depth of the current at the output frequency of the power switch tube (121). It is used to constrain the high-frequency induced current and reduce eddy current loss. The drive mechanism (141) is installed on the bottom plate of the rear chamber (130). The direction of movement of the drive mechanism (141) is perpendicular to the plane direction of the DC bus.

6. The UPS power supply cabinet for smart grid security defense according to claim 1, characterized in that: The front chamber (110) is close to the front panel. The front chamber (110) is equipped with a control motherboard (112) and an auxiliary power module (111). The control motherboard (112) is fixed to the bottom plate of the front chamber (110) by copper pillars. The auxiliary power module (111) is fixed to the side of the control motherboard (112) by screws. The front panel of the front chamber (110) has a heat dissipation semiconductor grille (113).

7. The UPS power supply cabinet for smart grid security defense according to claim 1, characterized in that: The power switch (121) is mounted on an aluminum-based heat sink (125) in the middle chamber (120). The bottom of the aluminum-based heat sink (125) is attached to the bottom plate of the middle chamber (120) with thermal grease, and heat is dissipated by the conduction of the bottom plate of the middle chamber (120). An energy storage inductor (122) is mounted on the side of the power switch (121) by a bracket. The energy storage inductor (122) is a toroidal magnetic core inductor. An input filter capacitor (124) and an output filter capacitor (123) are arranged at the front end and the rear end of the power switch (121), respectively.

8. The UPS power supply cabinet for smart grid security defense according to claim 1, characterized in that: The energy storage battery (131) is composed of multiple cylindrical supercapacitor cells connected in series. Each cylindrical supercapacitor cell is connected in series by a nickel sheet or copper braided strip. The positive electrode of the first cell leads out a positive bus line, and the negative electrode of the last cell leads out a negative bus line.

9. The UPS power supply cabinet for smart grid security defense according to claim 1, characterized in that: The power buffer assembly (100) has an L-shaped section slide rail (210) on each side of its base plate. The L-shaped section slide rail (210) is fixed to the chassis base plate by screws. The corresponding position inside the UPS emergency power cabinet is provided with a guide rail groove (200) that cooperates with the L-shaped section slide rail (210). The guide rail groove (200) is fixedly installed on the mounting beam on the side wall of the UPS emergency power cabinet.

10. The UPS power supply cabinet for smart grid security defense according to claim 1, characterized in that: The DC busbar is electrically connected to a voltage sampling circuit at its input end, and the output end of the voltage sampling circuit is electrically connected to the control motherboard (112) for real-time detection of the voltage change rate of the DC busbar.

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