A novel frequency converter control dual power switching device

Abstract

The utility model relates to electrical automation control technical field discloses a novel frequency converter control dual power switching device, contain UPS power supply, external power supply, switching control, power distribution, protection and state indicating module, realize dual power automatic switching through electrical circuit connection, UPS power module supplies power to PLC board etc. through independent DC circuit breaker, external power supply module supplies power for signal conditioning board etc. through control air switch, transformer, switching control module borrows relay, voltage sensor signal switching main spare power, triggers external supply and alarm when power failure, protection module is circuit with circuit breaker, lightning arrester, fuse protection, state indicating module uses indicating lamp to show power state, UPS energy storage maintains power supply when power failure, trouble light and output alarm, guarantee frequency converter control power stable, the utility model constructs dual power switching and protection, indication system, realizes frequency converter control power's automatic switching, stable power supply and trouble early warning, guarantees frequency converter and industrial production reliable operation.

Description

Technical Field

[0001] This utility model relates to the field of electrical automation control technology, specifically to a novel frequency converter control dual power supply switching device. Background Technology

[0002] In industrial production, frequency converters are critical electrical equipment, and the stability of their control power supply directly affects the reliability of system operation. When the external power supply suddenly fails or trips, an interruption in the control power supply will cause the frequency converter to be unable to output power, leading to production stoppages or even safety accidents. Especially for automatic bypass cabinet equipment such as fan frequency converters, a tripping of the control power circuit breaker can cause a complete loss of power within the control cabinet, severely affecting production continuity. Therefore, there is an urgent need for a technical solution that can ensure a continuous supply of control power.

[0003] Traditional frequency converter control power supplies typically use a single power supply method, meaning they are directly powered by an external AC power source without a backup power supply or automatic switching device. The advantages of this approach are its simple structure and low cost; however, its disadvantages are significant. When the external power supply fails (such as tripping or power loss), the control power supply is immediately interrupted, causing the frequency converter to stop. Furthermore, it cannot automatically restore power, heavily relying on manual intervention, impacting production efficiency, and making it poorly suited for scenarios with high continuity requirements.

[0004] In existing technologies, while some solutions introduce the concept of dual power supplies, they mostly employ manual switching or have simple switching logic. For example, some solutions only switch between primary and backup power supplies manually, or although relay switching is used, automatic detection and intelligent switching of power status are not implemented. The advantage is the addition of a backup power interface compared to a single-power-supply solution; however, manual switching cannot respond promptly to sudden power failures, and automatic switching solutions, if flawed in their logic, can suffer from switching delays and malfunctions. Furthermore, most existing technologies do not feature separate circuits for the control power supply, leaving the risk of a single-circuit failure leading to overall power loss. Utility Model Content

[0005] Based on the above-mentioned technical problems, this application discloses a novel inverter control dual power supply switching device, including a UPS power supply module, an external power supply module, a switching control module, a power distribution module, a protection module and a status indication module. The modules are connected by electrical lines to realize automatic switching control of dual power supplies.

[0006] The output terminal of the UPS power module is electrically connected to the DC power input terminal of the power distribution module through an independent DC circuit breaker, supplying power to the DC power interfaces of the PLC board, rectifier board, and cooling fan in the inverter control cabinet.

[0007] The AC power input terminal of the external power supply module is electrically connected to the AC power input terminal of the power distribution module through the external power supply control circuit breaker. After the external power supply is converted into the required voltage by the control transformer, it supplies power to the signal conditioning board of the control module, the AC power interface of the cooling fan and the drive circuit module.

[0008] The switching control module includes main switching relays KA0 and KA1 and intermediate relay KA2. The coil of the main switching relay is connected to the voltage sensor detection terminal of the UPS power module and the external power supply module through electrical lines. Its normally open contacts are connected in series with the DC power supply circuit from the UPS power module to the power distribution module and the AC power supply circuit from the external power supply module to the power distribution module, respectively. The normally closed contacts are used for backup power status indication.

[0009] The coil of intermediate relay KA2 is connected to the status signal terminal of the UPS power module, and its contacts are connected to the power supply control circuit and alarm interface of the external power supply module.

[0010] The independent DC circuit breaker QF0, external power supply control circuit breaker QF1 and QF2 in the protection module are connected in series in the power supply circuit, the surge arresters Z1 and Z0 are connected in parallel to the power input terminal, and the fuses FU1 and FU2 are connected in series in the primary coil circuit of the control transformer.

[0011] The status indication module includes a UPS power indicator HL1, an external power indicator HL2, and a fault alarm light HL3, which are respectively connected to the signal output terminal of the power distribution module through relay contacts. During normal operation, the UPS power supply takes priority. When power is lost, the power supply is switched to the external power supply through a relay. When both power sources fail, the UPS energy storage maintains power supply, and at the same time, the fault light is lit and a signal is output through the alarm interface.

[0012] Preferably, the UPS power module includes a UPS device, an independent DC circuit breaker QF0, a voltage sensor PT1, and a UPS power indicator HL1. The output terminals L+ and L- of the UPS device are electrically connected to the input terminals of the independent DC circuit breaker QF0 via wires. The voltage sensor PT1 is connected in parallel at the UPS output terminal to detect the power status. The output terminal of the independent DC circuit breaker QF0 is electrically connected to the DC power input terminals DC+ and DC- of the power distribution module via wires. The UPS power indicator HL1 is connected in parallel in the DC power supply circuit via wires, forming a power supply circuit and status detection and indication structure from the output terminal of the UPS device through the voltage sensor PT1 and the independent DC circuit breaker QF0 to the power distribution module.

[0013] Preferably, the external power supply module includes external AC power input terminals L1, L2, N, external power supply control circuit breakers QF1 and QF2, control transformers TM1 and TM2, voltage sensor PT2, and external power supply indicator light HL2. The external AC power input terminals are connected to the input terminals of the external power supply control circuit breakers QF1 and QF2 via electrical lines. The voltage sensor PT2 is connected in parallel between the input terminals to detect the external power supply status. The output terminals of the external power supply control circuit breakers QF1 and QF2 are connected to the primary coils of the control transformers TM1 and TM2 via electrical lines. Fuse FU1 and FU2 are connected in series in the primary coil circuit. The secondary coils of the control transformers TM1 and TM2 are connected to the AC power input terminals of the power distribution module via electrical lines. The external power supply indicator light HL2 is connected in parallel in the AC power supply circuit via wires, forming a complete external power supply circuit that includes power detection, overload protection, voltage conversion, and status indication.

[0014] Preferably, the main switching relays of the switching control module include main switching relays KA0 and KA1, a time relay KT1, and a relay base. The coils of the main switching relays KA0 and KA1 are connected to the signal output terminals of the voltage sensor PT1 of the UPS power module and the voltage sensor PT2 of the external power supply module through electrical circuits. The normally open contact of the main switching relay KA0 is connected in series in the DC power supply circuit from the UPS power module to the power distribution module, and the normally closed contact is connected to the external power supply status indication circuit. The normally open contact of the main switching relay KA1 is connected in series in the AC power supply circuit from the external power supply module to the power distribution module, and the normally closed contact is connected to the UPS power supply status indication circuit. The coil of the time relay KT1 is connected in parallel with the coil of KA0, and the delay contact is connected to the coil circuit of KA1, forming a control structure with a delay switching function to prevent power fluctuations from causing erroneous switching.

[0015] Preferably, the intermediate relay of the switching control module includes an intermediate relay KA2, an alarm buzzer HA, and a terminal block. The coil of the intermediate relay KA2 is connected to the fault signal output terminal of the voltage sensor PT1 of the UPS power module through an electrical circuit. The normally open contact of the intermediate relay KA2 is connected to the power supply control circuit of the external power supply module, the control circuit of the fault alarm light HL3, and the alarm buzzer HA through an electrical circuit. The terminal block is used to connect the various electrical circuits to form a logic structure that triggers the external power supply to start when the UPS power supply fails, and simultaneously activates the audible and visual alarm.

[0016] Preferably, the power distribution module includes DC power input terminals DC+ and DC-, AC power input terminals L and N, a PLC board, a rectifier board, a signal conditioning board, a drive circuit module, a cooling fan power interface, and a terminal block. The DC power input terminals DC+ and DC- are connected to the output terminals of the independent DC circuit breaker QF0 of the UPS power module through electrical lines, and are branched to the PLC board, the rectifier board, and the cooling fan DC power interface. The AC power input terminals L and N are connected to the secondary coils of the control transformers TM1 and TM2 through electrical lines, and are branched to the signal conditioning board, the drive circuit module, and the cooling fan AC power interface. The terminal block is used for connecting and branching the various load branches, forming a power distribution network covering all control loads and auxiliary equipment in the inverter control cabinet.

[0017] Preferably, the protection module includes an independent DC circuit breaker QF0, external power supply control circuit breakers QF1 and QF2, surge arresters Z1 and Z0, fuses FU1 and FU2, and a grounding terminal PE. The independent DC circuit breaker QF0 is connected in series between the output terminal of the UPS power module and the DC input terminal of the power distribution module. The external power supply control circuit breakers QF1 and QF2 are connected in series between the external power supply input terminal and the primary coil of the control transformer. The fuses FU1 and FU2 are connected in series in the primary coil circuit of the control transformer. The surge arrester Z1 is connected in parallel to the output terminal of the UPS power supply, and the surge arrester Z0 is connected in parallel between the external power supply input terminals. The grounding terminal PE is connected to the metal casing of each module and the protection devices through wires, forming a multi-layer protection structure that includes overload protection, short circuit protection, surge protection, and grounding protection.

[0018] Preferably, the novel inverter control dual power supply switching device further includes terminal blocks XT1 and XT2. Terminal block XT1 is disposed between the UPS power supply module and the power distribution module, and is used to connect the output terminals L+ and L- of the UPS equipment to the input wires of the independent DC circuit breaker QF0, as well as the DC power supply lines branched to the PLC board and the rectifier board. Terminal block XT2 is disposed between the external power supply module and the power distribution module, and is used to connect the secondary coils of the control transformers TM1 and TM2 to the AC power input terminals L and N, as well as the AC power supply lines branched to the signal conditioning board and the drive circuit module. The terminal blocks realize the standardized connection and branch management of the wires between the modules.

[0019] Preferably, the control power supply schematic also includes a temperature sensor RT1 for detecting the temperature inside the inverter control cabinet. It is connected to the analog input port of the PLC board via a wire. The PLC board controls the start and stop of the cooling fan according to the temperature signal. The power supply terminal of the temperature sensor RT1 obtains power through the DC power input terminals DC+ and DC- of the power distribution module, and the signal output terminal is connected to the AI0 port of the PLC board via a shielded twisted pair cable, forming a temperature detection and cooling control loop. When the temperature inside the cabinet exceeds the threshold, the cooling fan is automatically started to ensure the stable operating temperature of the device.

[0020] Preferably, the control power supply schematic includes a grounding busbar EB1 for system grounding, which is connected to the grounding terminal PE via a copper wire and is electrically connected to the metal casing of the UPS power module, the metal casing of the control transformer of the external power supply module, the metal base of the PLC board of the power distribution module, and the grounding terminal of the surge arrester of the protection module. The cross-sectional area of ​​the grounding busbar EB1 is not less than 16mm². 2 This forms a unified grounding protection network to prevent equipment leakage and electromagnetic interference from affecting the control circuit.

[0021] Compared with the prior art, the technical solution of this application has the following technical effects:

[0022] This invention significantly improves the reliability of the inverter control power supply through a dual-power independent circuit design and automatic switching logic. The UPS power module and the external power supply module are connected to the power distribution module through independent circuit breakers. When the UPS power supply fails, the main switching relay and intermediate relay of the switching control module automatically activate, seamlessly switching to the external power supply. This avoids the complete loss of control power due to a single power supply failure, and solves the problem of shutdown when the external power supply trips during traditional single power supply. It ensures that the inverter can continue to operate when the power supply is abnormal, effectively reducing the risk of production interruption.

[0023] This invention achieves comprehensive protection and real-time monitoring of the power supply system through the coordinated operation of a multi-layer protection module and a status indication module. The circuit breakers, fuses, surge arresters, and other devices in the protection module provide protection against overload, short circuit, and surge faults, preventing equipment damage due to abnormal power supply. The indicator lights and alarm devices in the status indication module display the power supply status in real time and issue audible and visual alarms in case of faults, facilitating timely detection and handling of problems by maintenance personnel. Compared to the simple protection configurations in existing technologies, this solution offers a more comprehensive protection system and more timely fault warnings.

[0024] This invention optimizes the operating environment and anti-interference capability of the device by introducing a temperature sensor and a grounding busbar. The temperature sensor monitors the temperature inside the control cabinet in real time, and automatically starts the cooling fan when the temperature exceeds the threshold, ensuring that each module operates at a suitable temperature and extending the service life of the equipment. The unified grounding network constructed by the grounding busbar can effectively prevent the impact of equipment leakage and electromagnetic interference on the control circuit, improving the stability of system operation. These auxiliary designs, together with the core power switching function, enable the device to maintain reliable operation in complex industrial environments, overcoming the shortcomings of poor environmental adaptability in existing technologies.

[0025] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the preferred embodiments of this application are described in detail below with reference to the accompanying drawings.

[0026] The above and other objects, advantages and features of this application will become more apparent to those skilled in the art from the following detailed description of specific embodiments in conjunction with the accompanying drawings. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0028] Figure 1 This is a structural diagram of a novel frequency converter control dual power supply switching device according to the present invention;

[0029] Figure 2 This is a circuit diagram of a novel frequency converter control dual power supply switching device according to the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. In the following description, specific details such as specific configurations and components are provided merely to help fully understand the embodiments of this application. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. In addition, for clarity and brevity, descriptions of known functions and structures are omitted in the embodiments.

[0031] It should be understood that the phrase "an embodiment" or "this embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "an embodiment" or "this embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0032] Furthermore, reference numerals and / or letters may be repeated in different examples within this application. Such repetition is for the purpose of simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or settings discussed.

[0033] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. The term " / and" in this article describes another type of relationship between related objects, indicating that two relationships can exist. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " in this article generally indicates that the related objects before and after it are in an "or" relationship.

[0034] In this article, the term "at least one" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, "at least one of A and B" can mean: A exists alone, A and B exist simultaneously, or B exists alone.

[0035] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion.

[0036] Example 1

[0037] This embodiment mainly describes a novel inverter-controlled dual-power switching device, such as... Figure 1 As shown, it includes a UPS power supply module, an external power supply module, a switching control module, a power distribution module, a protection module, and a status indicator module. The modules are connected by electrical lines to achieve automatic switching control between the two power supplies.

[0038] The output terminal of the UPS power module is electrically connected to the DC power input terminal of the power distribution module through an independent DC circuit breaker, supplying power to the DC power interfaces of the PLC board, rectifier board, and cooling fan in the inverter control cabinet.

[0039] The AC power input terminal of the external power supply module is electrically connected to the AC power input terminal of the power distribution module through the external power supply control circuit breaker. After the external power supply is converted into the required voltage by the control transformer, it supplies power to the signal conditioning board of the control module, the AC power interface of the cooling fan and the drive circuit module.

[0040] The switching control module includes main switching relays KA0 and KA1 and intermediate relay KA2. The coil of the main switching relay is connected to the voltage sensor detection terminal of the UPS power module and the external power supply module through electrical lines. Its normally open contacts are connected in series with the DC power supply circuit from the UPS power module to the power distribution module and the AC power supply circuit from the external power supply module to the power distribution module, respectively. The normally closed contacts are used for backup power status indication.

[0041] The coil of intermediate relay KA2 is connected to the status signal terminal of the UPS power module, and its contacts are connected to the power supply control circuit and alarm interface of the external power supply module.

[0042] The independent DC circuit breaker QF0, external power supply control circuit breaker QF1 and QF2 in the protection module are connected in series in the power supply circuit, the surge arresters Z1 and Z0 are connected in parallel to the power input terminal, and the fuses FU1 and FU2 are connected in series in the primary coil circuit of the control transformer.

[0043] The status indication module includes a UPS power indicator HL1, an external power indicator HL2, and a fault alarm light HL3, which are respectively connected to the signal output terminal of the power distribution module through relay contacts. During normal operation, the UPS power supply takes priority. When power is lost, the power supply is switched to the external power supply through a relay. When both power sources fail, the UPS energy storage maintains power supply, and at the same time, the fault light is lit and a signal is output through the alarm interface.

[0044] Furthermore, the UPS power module includes a G7 model UPS device, an independent DC circuit breaker QF0, a voltage sensor PT1, and a UPS power indicator HL1. The output terminals L+ and L- of the UPS device are electrically connected to the input terminals of the independent DC circuit breaker QF0 via wires. The voltage sensor PT1 is connected in parallel at the UPS output terminal to detect the power status. The output terminal of the independent DC circuit breaker QF0 is electrically connected to the DC power input terminals DC+ and DC- of the power distribution module via wires. The UPS power indicator HL1 is connected in parallel in the DC power supply circuit via wires, forming a power supply circuit and status detection and indication structure from the output terminal of the UPS device through the voltage sensor PT1 and the independent DC circuit breaker QF0 to the power distribution module.

[0045] Furthermore, the external power supply module includes external AC power input terminals L1, L2, N, external power supply control circuit breakers QF1 and QF2, control transformers TM1 and TM2, voltage sensor PT2, and external power supply indicator light HL2. The external AC power input terminals are connected to the input terminals of external power supply control circuit breakers QF1 and QF2 via electrical lines. The voltage sensor PT2 is connected in parallel between the input terminals to detect the external power supply status. The output terminals of external power supply control circuit breakers QF1 and QF2 are connected to the primary coils of control transformers TM1 and TM2 via electrical lines. The primary coil circuit is connected in series with fuses FU1 and FU2. The secondary coils of control transformers TM1 and TM2 are connected to the AC power input terminals of the power distribution module via electrical lines. The external power supply indicator light HL2 is connected in parallel in the AC power supply circuit via wires, forming a complete external power supply circuit that includes power detection, overload protection, voltage conversion, and status indication.

[0046] Furthermore, the main switching relays of the switching control module include main switching relays KA0 and KA1, a time relay KT1, and a relay base. The coils of the main switching relays KA0 and KA1 are connected to the signal output terminals of the voltage sensor PT1 of the UPS power module and the voltage sensor PT2 of the external power supply module through electrical circuits. The normally open contact of the main switching relay KA0 is connected in series in the DC power supply circuit from the UPS power module to the power distribution module, and the normally closed contact is connected to the external power supply status indication circuit. The normally open contact of the main switching relay KA1 is connected in series in the AC power supply circuit from the external power supply module to the power distribution module, and the normally closed contact is connected to the UPS power supply status indication circuit. The coil of the time relay KT1 is connected in parallel with the coil of KA0, and the delay contact is connected to the coil circuit of KA1, forming a control structure with a delay switching function to prevent power fluctuations from causing erroneous switching.

[0047] Furthermore, the intermediate relay of the switching control module includes an intermediate relay KA2, an alarm buzzer HA, and a terminal block. The coil of the intermediate relay KA2 is connected to the fault signal output terminal of the voltage sensor PT1 of the UPS power module through an electrical circuit. The normally open contact of the intermediate relay KA2 is connected to the power supply control circuit of the external power supply module, the control circuit of the fault alarm light HL3, and the alarm buzzer HA through an electrical circuit. The terminal block is used to connect the various electrical circuits to form a logic structure that triggers the external power supply to start when the UPS power supply fails, and simultaneously activates the audible and visual alarm.

[0048] Furthermore, the power distribution module includes DC power input terminals DC+ and DC-, AC power input terminals L and N, a PLC board, a rectifier board, a signal conditioning board, a drive circuit module, a cooling fan power interface, and a terminal block. The DC power input terminals DC+ and DC- are connected to the output terminals of the independent DC circuit breaker QF0 of the UPS power module through electrical lines, and are branched to the PLC board, the rectifier board, and the cooling fan DC power interface. The AC power input terminals L and N are connected to the secondary coils of the control transformers TM1 and TM2 through electrical lines, and are branched to the signal conditioning board, the drive circuit module, and the cooling fan AC power interface. The terminal block is used for connecting and branching the various load branches, forming a power distribution network covering all control loads and auxiliary equipment in the inverter control cabinet.

[0049] Furthermore, the protection module includes an independent DC circuit breaker QF0, external power supply control circuit breakers QF1 and QF2, surge arresters Z1 and Z0, fuses FU1 and FU2, and a grounding terminal PE. The independent DC circuit breaker QF0 is connected in series between the output terminal of the UPS power module and the DC input terminal of the power distribution module. The external power supply control circuit breakers QF1 and QF2 are connected in series between the external power supply input terminal and the primary coil of the control transformer. The fuses FU1 and FU2 are connected in series in the primary coil circuit of the control transformer. The surge arrester Z1 is connected in parallel to the UPS power output terminal, and the surge arrester Z0 is connected in parallel between the external power supply input terminals. The grounding terminal PE is connected to the metal casing of each module and the protection devices through wires, forming a multi-layer protection structure that includes overload protection, short circuit protection, surge protection, and grounding protection.

[0050] Furthermore, the novel inverter control dual power supply switching device also includes terminal blocks XT1 and XT2. Terminal block XT1 is located between the UPS power module and the power distribution module, and is used to connect the output terminals L+ and L- of the UPS equipment to the input wires of the independent DC circuit breaker QF0, as well as the DC power supply lines branched to the PLC board and rectifier board. Terminal block XT2 is located between the external power supply module and the power distribution module, and is used to connect the secondary coils of the control transformers TM1 and TM2 to the AC power input terminals L and N, as well as the AC power supply lines branched to the signal conditioning board and drive circuit module. The terminal blocks enable standardized connection and branch management of the wires between the modules.

[0051] Furthermore, the control power supply schematic also includes a temperature sensor RT1 for detecting the temperature inside the inverter control cabinet. It is connected to the analog input port of the PLC board via a wire. The PLC board controls the start and stop of the cooling fan based on the temperature signal. The power supply terminal of the temperature sensor RT1 obtains power through the DC power input terminals DC+ and DC- of the power distribution module, and the signal output terminal is connected to the AI0 port of the PLC board via a shielded twisted pair cable, forming a temperature detection and cooling control loop. When the temperature inside the cabinet exceeds the threshold, the cooling fan is automatically started to ensure the stable operating temperature of the device.

[0052] Furthermore, the control power supply schematic diagram includes a grounding busbar EB1 for system grounding, which is connected to the grounding terminal PE via a copper wire. It is also electrically connected to the metal casing of the UPS power module, the metal casing of the control transformer of the external power supply module, the metal base of the PLC board of the power distribution module, and the grounding terminal of the surge arrester of the protection module. The cross-sectional area of ​​the grounding busbar EB1 is not less than 16 mm². 2 This forms a unified grounding protection network to prevent equipment leakage and electromagnetic interference from affecting the control circuit.

[0053] This embodiment details the dual-power independent circuit system constructed in this application, which includes a UPS power supply module and an external power supply module. Fully automatic intelligent switching is achieved through a switching control module. The UPS power supply is designated as the primary power source, and the external power supply serves as a backup. A voltage sensor monitors the power status in real time, and the coordinated action of the main switching relay and intermediate relays enables millisecond-level automatic switching in the event of a power failure. Furthermore, the circuit design prevents single-circuit failures from affecting the overall power supply. Compared to existing technologies, its advantages lie in more intelligent switching, faster response, and more reliable power supply. It effectively solves problems such as switching delays and manual intervention in existing solutions, significantly improving the stability of the inverter control power supply and the continuity of the production system.

[0054] Based on Embodiment 1, this embodiment describes in detail the circuit of the novel inverter control dual power supply switching device, such as... Figure 2 As shown, specifically:

[0055] The power input section first completes the independent branch wiring of the UPS power module and the external power supply module; the output terminals L+ and L- of the G7UPS equipment are connected to the input terminals of the independent DC circuit breaker QF0 through cables, and then wires are led out from the output terminals of QF0 to the DC power input terminals DC+ and DC- of the power distribution module to form the UPS main power supply circuit; the external power supply is connected from the input terminals L1, L2, and N, and after passing through the external power supply control circuit breakers QF1 and QF2, it is connected to the primary coil of the control transformers TM1 and TM2. The output terminals of the secondary coils are connected to the AC power input terminals L and N of the power distribution module. It is important to strictly follow the wiring according to the "L and N markings" in the schematic diagram to avoid polarity errors. At the same time, a voltage sensor PT1 is connected in parallel at the UPS output terminal and PT2 is connected in parallel between the external power supply input terminals to detect the status of the two power supplies in real time and provide a signal basis for the subsequent switching logic;

[0056] The switching control module completes the wiring and logic configuration of the relays and time relays. The coils of the main switching relays KA0 and KA1 are connected to the signal output terminals of the UPS power module PT1 and the external power supply module PT2, respectively. The normally open contact of KA0 is connected in series in the DC circuit from the UPS to the power distribution module, and the normally closed contact is connected to the external power supply status indication circuit. The normally open contact of KA1 is connected in series in the AC circuit from the external power supply, and the normally closed contact is connected to the UPS status indication circuit. Simultaneously, the coil of the time relay KT1 is connected in parallel with the coil of KA0, and its delay contact is connected to the coil circuit of KA1 to prevent incorrect switching due to power fluctuations. The coil of the intermediate relay KA2 is connected to the fault signal output terminal of PT1, and its normally open contacts are connected to the circuits of the external power supply control circuit, the fault alarm light HL3, and the alarm buzzer HA, respectively. When the UPS power fails, KA2 activates, triggering the external power supply to start and activating the alarm. After the entire relay group is fixed by the base, the electrical connection between the coil and the contact is completed, ensuring accurate switching logic.

[0057] The power distribution module distributes DC and AC power to each load device. The DC power input terminals DC+ and DC-, after connecting to the QF0 output, are routed to the DC power interfaces of the PLC board, rectifier board, and cooling fan. The AC power input terminals L and N, after connecting to the secondary coil of the control transformer, are routed to the AC power interfaces of the signal conditioning board, drive circuit module, and cooling fan. All routes must be standardized using terminal blocks, such as XT1 between the UPS and the power distribution module, and XT2 between the external power supply and the distribution module, facilitating wiring branching and maintenance. Furthermore, the temperature sensor RT1 draws power from the DC power input, and its signal output is connected to the AI0 port of the PLC board via a shielded twisted-pair cable. When the cabinet temperature exceeds a threshold, the PLC board controls the cooling fan to start and stop, ensuring a stable operating environment for each module. The entire distribution process must be completed according to the load interfaces marked on the schematic diagram to avoid misconnections that could cause equipment malfunctions.

[0058] The protection module connects protection devices in series in each power supply circuit and completes the grounding network construction. An independent DC circuit breaker QF0 is connected in series between the UPS power output and DC input terminals. QF1 and QF2 are connected in series between the external power supply input terminals and the primary coil of the control transformer. Fuses FU1 and FU2 are connected in series in the primary coil circuit of the control transformer. Simultaneously, a surge arrester Z1 is connected in parallel at the UPS output terminal, and Z0 is connected in parallel between the external power supply input terminals to achieve overload, short circuit, and surge protection. In the grounding system, the grounding busbar EB1 is connected to the grounding terminal PE via a copper wire, and then electrically connected to the UPS metal casing, the control transformer TM1 / TM2 casing, the PLC board metal base, and the surge arrester grounding terminal, respectively. The cross-sectional area of ​​EB1 is not less than 16mm². 2 This forms a unified grounding network. Finally, the UPS power indicator HL1, external power indicator HL2, and fault alarm light HL3 of the status indicator module are connected to the signal output terminal of the power distribution module through the contacts of relays KA0, KA1, and KA2, respectively. After completion, the operating threshold and grounding resistance of each protection device need to be tested to ensure the reliable operation of the protection system.

[0059] This embodiment describes in detail the novel dual-power switching circuit for inverter control. Through independent dual-power branching, automatic switching logic, a complete protective grounding system, and intelligent load distribution, it achieves millisecond-level automatic switching in the event of a power failure, avoiding inverter shutdown caused by power outage. It also features overload, short-circuit, surge protection, and temperature monitoring functions, improving system reliability. The status indication and alarm devices facilitate real-time operation and maintenance, ensuring the continuity and safety of industrial production.

[0060] The above are merely preferred embodiments of the present utility model, and are not intended to limit the scope of protection of the present utility model. For those skilled in the art, the present utility model can have various modifications and variations. Any changes, modifications, substitutions, integrations, and parameter changes made to these embodiments within the spirit and principles of the present utility model, without departing from the principles and spirit of the present utility model, through conventional substitutions or to achieve the same function, shall fall within the scope of protection of the present utility model.

Claims

1. A novel frequency converter-controlled dual-power switching device, characterized in that, It includes a UPS power supply module, an external power supply module, a switching control module, a power distribution module, a protection module, and a status indicator module. The modules are connected by electrical lines to achieve automatic switching control between the two power supplies. The output terminal of the UPS power module is electrically connected to the DC power input terminal of the power distribution module through an independent DC circuit breaker, supplying power to the DC power interfaces of the PLC board, rectifier board, and cooling fan in the inverter control cabinet. The AC power input terminal of the external power supply module is electrically connected to the AC power input terminal of the power distribution module through the external power supply control circuit breaker. After the external power supply is converted into the required voltage by the control transformer, it supplies power to the signal conditioning board of the control module, the AC power interface of the cooling fan and the drive circuit module. The switching control module includes main switching relays KA0 and KA1 and intermediate relay KA2. The coil of the main switching relay is connected to the voltage sensor detection terminal of the UPS power module and the external power supply module through electrical lines. Its normally open contacts are connected in series with the DC power supply circuit from the UPS power module to the power distribution module and the AC power supply circuit from the external power supply module to the power distribution module, respectively. The normally closed contacts are used for backup power status indication. The coil of intermediate relay KA2 is connected to the status signal terminal of the UPS power module, and its contacts are connected to the power supply control circuit and alarm interface of the external power supply module. The independent DC circuit breaker QF0, external power supply control circuit breaker QF1 and QF2 in the protection module are connected in series in the power supply circuit, the surge arresters Z1 and Z0 are connected in parallel to the power input terminal, and the fuses FU1 and FU2 are connected in series in the primary coil circuit of the control transformer. The status indication module includes a UPS power indicator HL1, an external power indicator HL2, and a fault alarm light HL3, which are respectively connected to the signal output terminal of the power distribution module through relay contacts. During normal operation, the UPS power supply takes priority. When power is lost, the power supply is switched to the external power supply through a relay. When both power sources fail, the UPS energy storage maintains power supply, and at the same time, the fault light is lit and a signal is output through the alarm interface.

2. The novel inverter control dual power supply switching device according to claim 1, characterized in that, The UPS power module includes a UPS device, an independent DC circuit breaker QF0, a voltage sensor PT1, and a UPS power indicator HL1. The output terminals L+ and L- of the UPS device are electrically connected to the input terminals of the independent DC circuit breaker QF0 via wires. The voltage sensor PT1 is connected in parallel at the UPS output terminal to detect the power status. The output terminal of the independent DC circuit breaker QF0 is electrically connected to the DC power input terminals DC+ and DC- of the power distribution module via wires. The UPS power indicator HL1 is connected in parallel in the DC power supply circuit via wires, forming a power supply circuit and status detection and indication structure from the output terminal of the UPS device through the voltage sensor PT1 and the independent DC circuit breaker QF0 to the power distribution module.

3. The novel inverter control dual power supply switching device according to claim 1, characterized in that, The external power supply module includes external AC power input terminals L1, L2, and N, external power supply control circuit breakers QF1 and QF2, control transformers TM1 and TM2, voltage sensor PT2, and external power supply indicator light HL2. The external AC power input terminals are connected to the input terminals of external power supply control circuit breakers QF1 and QF2 via electrical circuits. Voltage sensor PT2 is connected in parallel between the input terminals to detect the external power supply status. The output terminals of external power supply control circuit breakers QF1 and QF2 are connected to the primary coils of control transformers TM1 and TM2 via electrical circuits. Fuse FU1 and FU2 are connected in series in the primary coil circuit. The secondary coils of control transformers TM1 and TM2 are connected to the AC power input terminals of the power distribution module via electrical circuits. External power supply indicator light HL2 is connected in parallel in the AC power supply circuit via wires, forming a complete external power supply circuit.

4. A novel inverter control dual power supply switching device according to claim 1, characterized in that, The main switching relays of the switching control module include main switching relays KA0 and KA1, a time relay KT1, and a relay base. The coils of the main switching relays KA0 and KA1 are connected to the signal output terminals of the voltage sensor PT1 of the UPS power module and the voltage sensor PT2 of the external power supply module through electrical circuits. The normally open contact of the main switching relay KA0 is connected in series in the DC power supply circuit from the UPS power module to the power distribution module, and the normally closed contact is connected to the external power supply status indication circuit. The normally open contact of the main switching relay KA1 is connected in series in the AC power supply circuit from the external power supply module to the power distribution module, and the normally closed contact is connected to the UPS power supply status indication circuit. The coil of the time relay KT1 is connected in parallel with the coil of KA0, and the delay contact is connected to the coil circuit of KA1 to prevent power fluctuations from causing erroneous switching.

5. A novel inverter control dual power supply switching device according to claim 1, characterized in that, The intermediate relay of the switching control module includes an intermediate relay KA2, an alarm buzzer HA, and a terminal block. The coil of the intermediate relay KA2 is connected to the fault signal output terminal of the voltage sensor PT1 of the UPS power module through an electrical circuit. The normally open contact of the intermediate relay KA2 is connected to the power supply control circuit of the external power supply module, the control circuit of the fault alarm light HL3, and the alarm buzzer HA through an electrical circuit. The terminal block is used to connect the various electrical circuits to form a logic structure that triggers the external power supply to start when the UPS power supply fails, and at the same time activates the audible and visual alarm.

6. A novel inverter control dual power supply switching device according to claim 1, characterized in that, The power distribution module includes DC power input terminals DC+ and DC-, AC power input terminals L and N, a PLC board, a rectifier board, a signal conditioning board, a drive circuit module, a cooling fan power interface, and a terminal block. The DC power input terminals DC+ and DC- are connected to the output terminal of the independent DC circuit breaker QF0 of the UPS power module through electrical lines, and are branched to the PLC board, the rectifier board, and the cooling fan DC power interface. The AC power input terminals L and N are connected to the secondary coils of the control transformers TM1 and TM2 through electrical lines, and are branched to the signal conditioning board, the drive circuit module, and the cooling fan AC power interface. The terminal block is used for connecting and branching the various load branches to form a power distribution network.

7. A novel inverter control dual power supply switching device according to claim 1, characterized in that, The protection module includes an independent DC circuit breaker QF0, external power supply control circuit breakers QF1 and QF2, surge arresters Z1 and Z0, fuses FU1 and FU2, and a grounding terminal PE. The independent DC circuit breaker QF0 is connected in series between the output terminal of the UPS power module and the DC input terminal of the power distribution module. The external power supply control circuit breakers QF1 and QF2 are connected in series between the external power supply input terminal and the primary coil of the control transformer. The fuses FU1 and FU2 are connected in series in the primary coil circuit of the control transformer. The surge arrester Z1 is connected in parallel to the UPS power output terminal, and the surge arrester Z0 is connected in parallel between the external power supply input terminals. The grounding terminal PE is connected to the metal casing of each module and the protection devices through wires.

8. A novel inverter control dual power supply switching device according to claim 1, characterized in that, The novel inverter control dual power switching device also includes terminal blocks XT1 and XT2. The terminal block XT1 is located between the UPS power module and the power distribution module and is used to connect the output terminals L+ and L- of the UPS equipment with the input wires of the independent DC circuit breaker QF0, as well as the DC power supply lines branched to the PLC board and the rectifier board. The terminal block XT2 is located between the external power supply module and the power distribution module. It is used to connect the wires of the secondary coils of the control transformers TM1 and TM2 to the AC power input terminals L and N, as well as the AC power supply lines branched to the signal conditioning board and drive circuit module. The terminal block enables standardized connection and branch management of the wires between the modules.

9. A novel inverter control dual power supply switching device according to claim 1, characterized in that, The dual power supply switching device also includes a temperature sensor RT1 for detecting the temperature inside the inverter control cabinet. It is connected to the analog input port of the PLC board via a wire. The PLC board controls the start and stop of the cooling fan based on the temperature signal. The power supply terminal of the temperature sensor RT1 obtains power through the DC power input terminals DC+ and DC- of the power distribution module, and the signal output terminal is connected to the AI0 port of the PLC board via a shielded twisted pair cable, forming a temperature detection and cooling control loop. When the temperature inside the cabinet exceeds the threshold, the cooling fan is automatically started to ensure the stable operating temperature of the device.

10. A novel inverter control dual power supply switching device according to claim 1, characterized in that, The dual power supply switching device is equipped with a grounding busbar EB1 for system grounding. It is connected to the grounding terminal PE through a copper wire and is electrically connected to the metal casing of the UPS power module, the metal casing of the control transformer of the external power supply module, the metal base of the PLC board of the power distribution module, and the grounding terminal of the surge arrester of the protection module. The cross-sectional area of ​​the grounding busbar EB1 is not less than 16mm², forming a unified grounding protection network to prevent equipment leakage and electromagnetic interference from affecting the control circuit.

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