Centralized direct-current power supply lighting system

Abstract

The invention discloses a centralized direct-current power supply lighting system, and the system comprises a centralized direct-current power supply cabinet which is used for rectifying a three-phase alternating current into a DC 0V-DC 1000V constant-voltage direct current and outputting the DC 0V-DC 1000V constant-voltage direct current; comprising a plurality of constant-current control devices which are respectively arranged in output loops of the direct-current power supply cabinet and are used for converting constant-voltage direct current into constant current and outputting the constant current; comprising a plurality of lamps only comprising LED light source modules, and a built-in constant-current power supply and an electrolytic capacitor are not arranged; comprising a three-wire system power supply line. By the adoption of the centralized direct-current power supply lighting system, no electrolytic capacitor or complex power supply circuit exists in the lamp, no input capacitor exists at the lamp end, LC resonance formed by line inductance is avoided, power-on pulses are eliminated, and the voltage equalizing line is additionally arranged, so that the actual voltage difference borne by each lamp is consistent regardless of the distance of the installation position; and uniform illumination brightness is ensured. The LED lamp is suitable for various outdoor LED lighting scenes such as urban roads, tunnels and squares, is also suitable for indoor lighting scenes with high lighting concentration, and is very practical.

Description

Technical Field

[0001] This invention relates to the field of LED lighting technology, and more particularly to a centralized DC power supply lighting system. Background Technology

[0002] Currently, indoor and outdoor LED lighting commonly uses AC mains power, such as AC220V, which is converted to DC by a distributed constant current power supply to drive the LED light source. Each independent LED luminaire has its own independent constant current power supply, which converts AC220V to DC to drive the LED light source. This constant current power supply must contain a large-capacity electrolytic capacitor to smooth the pulsating DC voltage after rectification. Because the voltage fluctuation after AC220V rectification is relatively large, the electrolytic capacitor is in a high-frequency charging and discharging state for a long time, and the operating environment temperature is high, which easily leads to capacitance decay, increased leakage current, and ultimately power supply failure.

[0003] To improve reliability, some systems have switched to centralized DC power supply cabinets. Since the three-phase AC power is rectified into high-voltage DC, typically ranging from DC460V to DC560V, it supplies power to multiple LED lights in a constant-voltage manner. This uses a small voltage difference to improve the reliability of the capacitors at the centralized power supply end. However, to meet the constant current requirements of the light sources, a small constant current source must still be retained at the lamp end, and a filter capacitor must be configured on the input side of this constant current source. The filter capacitor and the distributed inductance of the power supply line can easily form an LC resonant circuit at the moment of system power-on, generating high-frequency, high-voltage, high-current pulses. This can easily impact the LED chips, reducing LED luminous efficacy, accelerating chip aging, and shortening the lifespan of the lamps.

[0004] Therefore, there is an urgent need for a centralized DC power supply lighting system that can eliminate the dependence on electrolytic capacitors at the lamp end, suppress power-on resonance, and achieve current balance among multiple lamps. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a centralized DC power supply lighting system with high reliability and stable current. This is achieved by moving the constant current control function to the centralized power supply end and optimizing the wiring structure, completely eliminating the electrolytic capacitors and constant current circuits inside the lamps, and simultaneously solving the problem of uneven current caused by line voltage drop. The technical solution adopted by this invention is as follows:

[0006] A centralized DC power supply lighting system, characterized in that it comprises:

[0007] Centralized DC power supply cabinet, used to rectify three-phase AC power into constant voltage DC output of DC0V–DC1000V;

[0008] Multiple constant current control devices are respectively installed in each output circuit of the DC power supply cabinet to convert constant voltage DC into constant current output;

[0009] Multiple lamps containing only LED light source modules, without built-in constant current power supplies and electrolytic capacitors;

[0010] The three-wire power supply line includes a positive main line, a negative main line, and an equalizing line; the positive main line is connected to the positive terminal of each lamp, the equalizing line is connected to the negative terminal of each lamp, and the end of the equalizing line is connected to the negative main line to form a current return path.

[0011] The centralized DC power supply cabinet is equipped with a constant voltage module.

[0012] The constant current control device is integrated inside the DC power supply cabinet or installed at the beginning of each circuit, and has overvoltage, overcurrent and short circuit protection functions.

[0013] The equalizing wire uses a conductor with the same or similar cross-sectional area as the positive main wire to ensure that its impedance is low enough so that the negative terminal potential of all lamps is basically the same.

[0014] The LED lamp is a simple light source string structure, and its current-voltage characteristic is stable and conductive under rated operating current, requiring no additional driving circuit.

[0015] Beneficial effects:

[0016] The centralized DC power supply lighting system of this invention eliminates the need for electrolytic capacitors and complex power circuits inside the lamps, and removes input capacitors at the lamp terminals. This avoids LC resonance with the line inductance, eliminates power-on pulses, protects the LED chips, and ensures that the negative terminals of all lamps are at the same potential by adding equalizing lines. Regardless of the installation location, each lamp bears the same actual voltage difference, thereby achieving precise current balance and ensuring uniform lighting brightness.

[0017] Its centralized constant current control facilitates monitoring and maintenance, simplifies the lamp structure, reduces manufacturing and replacement costs, and is suitable for various outdoor LED lighting scenarios such as urban roads, tunnels, and squares. It is also suitable for indoor lighting scenarios with high lighting concentration, making it very practical. Attached Figure Description

[0018] Figure 1 is a circuit diagram of the system structure of the present invention;

[0019] Figure 2 is a wiring diagram of the electrical cabinet of the system of the present invention;

[0020] Figure 3 This is the wiring circuit diagram for the lamp of the present invention;

[0021] In the diagram: AC380V is the three-phase AC power input line; QF1 is the main circuit breaker; SPD is the surge suppressor; AC-DC modules 1-N are rectifier and filter voltage regulator modules; QF01 is the main circuit breaker; QF02~QFN are circuit breakers; KM1~KMN are circuit contactors; constant current modules-1~N are constant current control devices; WL1-N are LED light source modules.

[0022] DC + is the positive main line; DC - is the negative main line; S is the equalizing line; lamps 1#~N# are electrolytic capacitor-free LED lamps; PE is the protective ground line. Detailed Implementation

[0023] The technical solution of the present invention will now be clearly and completely described in conjunction with the accompanying drawings. In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] The invention will now be further described with reference to the accompanying drawings.

[0026] Please refer to the following: Figures 1-3 A centralized DC power supply lighting system, characterized in that it comprises:

[0027] Centralized DC power supply cabinet, used to rectify three-phase AC power into constant voltage DC output of DC0V–DC1000V;

[0028] Multiple constant current control devices are respectively installed in each output circuit of the DC power supply cabinet to convert constant voltage DC into constant current output;

[0029] Multiple lamps containing only LED light source modules, without built-in constant current power supplies and electrolytic capacitors;

[0030] The three-wire power supply line includes a positive main line, a negative main line, and an equalizing line; the positive main line is connected to the positive terminal of each lamp, the equalizing line is connected to the negative terminal of each lamp, and the end of the equalizing line is connected to the negative main line to form a current return path.

[0031] The centralized DC power supply cabinet is equipped with a constant voltage module.

[0032] The constant current control device is integrated inside the DC power supply cabinet or installed at the beginning of each circuit, and has overvoltage, overcurrent and short circuit protection functions.

[0033] As shown in the figure, the AC380V three-phase AC power input is connected to a voltage regulator module formed by the QF1 main circuit breaker, SPD surge suppressor, and multiple AC-DC modules 1-N rectifier and filter. Then, through the QF01 main circuit breaker, multiple QF02~QFN circuit breakers, KM1~KMN circuit contactors, and multiple constant current modules -1~N, a constant current output current is generated. These constant current modules -1~N are respectively connected to the WL1-N LED light source modules. Each light source module is connected to the positive terminal of each lamp via a DC + positive main line, and the equalizing line S is connected to the negative terminal of each lamp. The end of the equalizing line S is connected to the DC - negative main line, forming a current return path circuit connection.

[0034] Its three-phase AC power is connected to a centralized DC power supply cabinet, and after passing through a three-phase rectifier bridge and a filter voltage regulator circuit, it outputs DC 375V or DC 750V (common value) high-voltage DC. This DC bus is divided into N independent output circuits, each circuit is connected in series with a constant current control device (such as a module based on Buck or Linear constant current IC), and the output current is set to I0, such as 5000mA.

[0035] Each circuit is laid outwards via two cables: a positive main line (+) and a negative main line (−). N LED lights are installed along the circuit. Starting with the first light, an equalizing line (S) is added. Each light has only two terminals: the positive terminal connects to the positive main line, and the negative terminal connects to the equalizing line S. The equalizing line S is connected to the negative main line (−) at the farthest light fixture via a jumper wire, forming a closed circuit.

[0036] Since the equalizing line S "short-circuit" the negative terminals of all lamps to the same potential point, ignoring the small voltage drop, and the potential of each point on the positive main line is kept stable by the constant current device, the voltage at both ends of each lamp is basically the same, and the current flowing through the LED is highly consistent.

[0037] Actual measurements show that, at a power supply distance of 1 kilometer, the current deviation at the end of a traditional two-wire system can reach 15%, while the current deviation of the system of this invention is less than 1%.

[0038] In addition, an intelligent controller is set up in the DC power supply cabinet and connected to the constant voltage module and constant current control device respectively, forming an extension of intelligent monitoring and control. It can communicate with the intelligent controller and constant current control module via RS485 bus, and connect to the line status monitoring sensor and optical sensor via LoRa wireless communication; it also interfaces with the cloud management platform via Ethernet interface.

[0039] The system collects ambient light intensity in real time using a light sensor. For example, when the ambient light intensity is higher than 500 lux, the intelligent constant current control module reduces the output current to 1A, i.e., dimming to 30% brightness; when the ambient light intensity is lower than 100 lux, the control module outputs the full 3A current, i.e., 100% brightness; when the system detects the period from 23:00 to 5:00 the next day, it automatically adjusts the brightness to 50% and the current to 1.5A, achieving energy saving on demand.

[0040] Furthermore, the intelligent monitoring and control unit collects current, voltage, and power data of each circuit in real time, as well as line temperature and lamp operating status information, stores them in a local database and synchronizes them to the cloud management platform. Users can view the system's operating status through the human-machine interface or mobile APP.

[0041] By adopting the above system, the lamps are free of electrolytic capacitors and complex power supply circuits, and there are no input capacitors at the lamp terminals. This avoids LC resonance with the line inductance, eliminates power-on pulses, protects the LED chips, and by adding equalizing lines, the negative terminals of all lamps are made to be at the same potential. Regardless of the installation location, the actual voltage difference of each lamp is consistent, thereby achieving precise current balance and ensuring uniform lighting brightness.

[0042] Its centralized constant current control facilitates monitoring and maintenance, simplifies the lamp structure, reduces manufacturing and replacement costs, and is suitable for various outdoor LED lighting scenarios such as urban roads, tunnels, and squares. It is also suitable for indoor lighting scenarios with high lighting concentration, making it very practical.

[0043] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

[0044] Other parts of this invention that are not detailed herein are all prior art and will not be described further here.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A centralized DC power supply lighting system, characterized in that, include: Centralized DC power supply cabinet, used to rectify three-phase AC power into constant voltage DC output of DC0V–DC1000V; Multiple constant current control devices are respectively installed in each output circuit of the DC power supply cabinet to convert constant voltage DC into constant current output; Multiple lamps containing only LED light source modules, without built-in constant current power supplies and electrolytic capacitors; The three-wire power supply line includes a positive main line, a negative main line, and an equalizing line; the positive main line is connected to the positive terminal of each lamp, the equalizing line is connected to the negative terminal of each lamp, and the end of the equalizing line is connected to the negative main line to form a current return path.

2. The centralized DC power supply lighting system according to claim 1, characterized in that, The centralized DC power supply cabinet is equipped with a constant voltage module.

3. The centralized DC power supply lighting system according to claim 1, characterized in that, The constant current control device is integrated inside the DC power supply cabinet or installed at the starting end of each circuit.

4. The centralized DC power supply lighting system according to claim 1, characterized in that, The equalizing line uses a conductor with the same or similar cross-sectional area as the positive electrode main line.

5. The centralized DC power supply lighting system as described in claim 1, characterized in that, The LED lamp is a simple light source string structure, and its volt-ampere characteristic is stable in a conducting state under the rated operating current, without the need for an additional driving circuit.

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