Redundant lighting driver system

Abstract

A redundant lighting driver system includes a primary driver and a backup driver. The primary and backup drivers are electrically coupled to receive alternating current (AC) power from a power source. Either the primary or backup driver supplies power to the light source sequentially. The primary driver is configured to provide primary power to the light source, and the backup driver is configured to provide backup power to the light source when the primary power source is unavailable. The backup driver is designed to withstand larger power surges than the primary driver.

Description

Technical Field

[0001] This invention relates generally to lighting solutions, and more specifically to redundant lighting driver systems. Background Technology

[0002] Drivers are typically used to supply power to one or more light sources in a lighting fixture. For example, a light-emitting diode (LED) driver can power one or more LED light sources in one or more lighting fixtures. Typically, an LED driver can receive AC (alternating current) power (e.g., mains power) and generate DC (direct current) power to supply one or more light sources. U.S. Patent Publication No. 2014 / 0252948 discloses an elevator interior lighting assembly having a main LED driver that provides regulated DC power to a main LED and a backup LED, and the backup LED receives DC power from a backup power supply when the main power supply is not providing AC power. Drivers are generally desirable to have a good power factor and low harmonic distortion for efficient operation. However, drivers for outdoor or other types of luminaires can be damaged by power surges, preventing the driver from supplying sufficient power to the luminaire. This damage can cause the luminaire to fail to provide light. In some cases, surge protection units can be placed before or integrated into the luminaire's driver. However, many surge protection modules typically prevent initial power surge exposure but are susceptible to failure due to subsequent power surges. In cases where luminaires are installed in public places (e.g., stadiums) and other situations, a complete interruption of light can be very inconvenient. Therefore, a solution is needed that allows luminaires to continue providing light even after the luminaire's driver fails. Summary of the Invention

[0003] This disclosure generally relates to lighting solutions, and more specifically to redundant lighting driver systems. In an example embodiment, the redundant lighting driver system includes a primary driver and a backup driver. The primary driver and the backup driver are electrically coupled to receive alternating current (AC) power from a power source. Either the primary driver or the backup driver supplies power to a light source. The primary driver is configured to provide primary power to the light source, and the backup driver is configured to provide backup power to the light source when the primary power source is unavailable. The backup driver is designed to withstand larger power surges than the primary driver.

[0004] In another example embodiment, the lighting system includes a primary driver and a backup driver, wherein the primary driver and the backup driver are electrically coupled to receive alternating current (AC) power from a power source. The lighting system also includes a light source, wherein either the primary driver or the backup driver supplies power to the light source. The primary driver is configured to provide primary power to the light source, and the backup driver is configured to provide backup power to the light source when primary power is unavailable. The backup driver is designed to withstand larger power surges than the primary driver.

[0005] These and other aspects, objects, features, and embodiments will be apparent from the following description and the appended claims. Attached Figure Description

[0006] Referring now to the accompanying drawings, which are not necessarily drawn to scale, and in which:

[0007] Figure 1 A lighting system including a redundant lighting driver system is shown according to an example embodiment;

[0008] Figure 2 It shows Figure 1 The lighting system illustrates some details of a redundant lighting driver system according to an example embodiment;

[0009] Figure 3 An example embodiment is shown. Figure 2 A graph of the input voltage at the input of the backup driver in a redundant lighting driver system;

[0010] Figure 4 A graph of a direct current (DC) voltage according to an example embodiment is shown, the DC voltage being generated by... Figure 3 The transient voltage surge shown indicates an increase in the output voltage of the standby driver.

[0011] Figure 5 The example embodiment is shown in the corresponding Figure 2 The inductor of the inductor unit; and

[0012] Figure 6 The example embodiment is shown in the corresponding Figure 2 The transformer of the inductor unit.

[0013] The accompanying drawings illustrate only exemplary embodiments and should not be considered as limiting the scope. The elements and features shown in the drawings are not necessarily drawn to scale, but rather the focus is on clearly illustrating the principles of the exemplary embodiments. Additionally, certain dimensions or positions may be exaggerated to aid in visual communication of these principles. In the drawings, the same reference numerals used in different figures may denote similar or corresponding elements, but do not necessarily represent the same elements. Detailed Implementation

[0014] In the following paragraphs, exemplary embodiments will be described in more detail with reference to the accompanying drawings. Well-known components, methods, and / or processing techniques are omitted or briefly described in this specification. Furthermore, references to various features of the embodiments do not imply that all embodiments must include the referenced features(s).

[0015] Figure 1A lighting system 100 including a redundant lighting driver system 102 is shown according to an example embodiment. For example, the lighting system 100 may be an outdoor luminaire 100 that provides illumination to areas where light interruption is inconvenient (e.g., stadiums, parking lots, etc.). As another example, the lighting system 100 may be an indoor luminaire 100 that provides illumination to areas such as, for example, an indoor stadium. In some exemplary embodiments, the lighting system 100 includes a redundant lighting driver system 102 and a light source 110. For example, the light source 110 may be a light-emitting diode (LED) light source including a plurality of LEDs having a forward voltage V across them. F For example, if light source 110 has five LEDs arranged in series, then the forward voltage V F This can be the total forward voltage across the five LEDs. The current I supplied to the light source 110 by the redundant lighting driver system 102 is... DC It must be sufficient to make the light source 110 emit light.

[0016] In some example embodiments, the redundant lighting driver system 102 receives AC power from an AC source 108 (e.g., a utility power supply or AC mains power). For example, the AC source 108 may provide an AC voltage V to the redundant lighting driver system 102. IN It can include AC voltage V. IN Input voltage V I Provided to redundant lighting driver system 102. For example, input voltage V. I Transient voltage surges may be included, which can be introduced into the power line connecting the AC power supply 108 and the redundant lighting driver system 102. Typically, transient voltage surges are characterized by very short-duration, very large voltage spikes. For example, transient voltage surges can have durations between 10 μs and 1000 μs and can reach peak voltages of 40 kV or higher. Transient voltage surges are typically caused by heavy load switching or lightning strikes. When no other voltage is introduced into the line connection between the AC power supply 108 and the redundant lighting driver system 102, the input voltage V... I Basically related to AC voltage V IN same.

[0017] In some example embodiments, the redundant lighting driver system 102 includes a primary driver 104 and a backup driver 106. Both the primary driver 104 and the backup driver 106 are electrically coupled to an AC power supply 108. The input voltage V supplied to the redundant lighting driver system 102 is... I It is supplied to the main driver 104 and the backup driver 106. The main driver 104 is designed to receive input power V. I The main power is supplied to the light source 110, while the backup power 106 is designed to draw power from the input power V.I Backup power is provided to the light source 110. The redundant lighting driver system 102 is designed such that the backup power is less than the main power.

[0018] For illustration, the main driver 104 is designed to provide a main current I to the light source 110. DC1 The backup driver 106 is designed to provide backup current I to the light source 110. DC2 For example, the main driver 104 can be a constant current driver, which is designed to operate based on the input voltage V. I The corresponding level provides a specific amount of current I. DC1 Input voltage V I Without input power surge / transient voltage surge, and with AC voltage V IN The same. The redundant lighting driver system 102 is designed such that the primary driver 104 or the standby driver 106 sequentially supplies current I to the light source 110. DC That is, the main driver 104 and the standby driver 106 do not supply power to the light source 110 at the same time, except during the transition time when switching between drivers 104 and 106.

[0019] In some example embodiments, the redundant lighting driver system 102 may include power diodes 112 and 114. The anode of power diode 112 is coupled to the output of the primary driver 104, while the anode of power diode 114 is coupled to the output of the standby driver 106. The cathodes of power diodes 112 and 114 are electrically connected to each other, for example, at node 116, where the current I... DC1 or current I DC2 Simultaneously, power is supplied to the light source 110 through node 116. To illustrate, when the main driver 104 supplies power to the light source 110, the current I supplied to the light source 110 is... DC Corresponding to the current I provided by the main driver 104 DC1 When the standby driver 106 supplies power to the light source 110, the current I... DC Corresponding to the current I provided by the backup driver 106 DC2 .

[0020] In some example embodiments, the redundant lighting driver system 102 is designed such that when the primary driver 104 is operating normally, the primary driver 104, rather than the backup driver 106, powers the light source 110. That is, at a specific AC voltage V supplied to the redundant lighting driver system 102... IN At this point, the current I from the main driver 104 DC1 Greater than current I DC2 This results in power diode 112 being forward biased and power diode 114 being reverse biased, wherein the current I through light source 110...DC It is the current I DC1 When the main driver 104 cannot provide current I DC1 Or a fault occurs causing current I DC1 Less than current I DC2 At this time, power diode 114 is forward biased and power diode 112 is reverse biased, wherein the current I through light source 110 is... DC It is the current I DC2 .

[0021] In some example embodiments, the main driver 104 can provide power factor correction, which can increase energy efficiency and reduce power costs. The main driver 104 can also perform current regulation to provide regulated current to the light source 110. For illustration, current I... DC1 The current may be regulated, which varies meaninglessly due to load variations caused by the light source 110. The main driver 104 may also include other components, such as a rectifier, an output transformer, etc., which will be readily understood by those skilled in the art who benefit from the scope of this disclosure. Different ways of implementing power factor correction, current regulation, and other common functions of the main driver 104 are well known to those skilled in the art. For illustration, the main driver 104 may be a readily available constant current driver. In some example embodiments, the main driver 104 may include a surge protection unit to prevent input voltage V that may occur when supplied to the redundant lighting driver system 102. I Input power surges. Alternatively, the main driver 104 may not include a surge protection unit. In some other alternative embodiments, an external surge protection unit may be positioned to provide surge protection to the main driver 104, as will be readily understood by those skilled in the art who benefit from the scope of this disclosure.

[0022] In some example embodiments, the backup driver 106 may be designed to include robust surge protection against input power surges. For example, the backup driver 106 includes a surge protection unit to prevent input voltage V that may occur when supplied to the redundant lighting driver system 102. I Power surges. To illustrate, even when the main drive 104 includes a power surge protection unit, the standby drive 106 provides more power surge protection than the main drive 104. For example, compared to the main drive 104 or the surge protection unit coupled to the main drive 104, the standby drive 106 can provide protection against higher surge energy and higher power surges.

[0023] In some example embodiments, because the primary purpose of the backup driver 106 is to provide backup power to the light source 110 until the defective main driver (e.g., the main driver 104 that has failed) is repaired or replaced, the quality of the backup power provided by the backup driver 106 may be relatively lower than the quality of the main power provided by the main driver 104. For example, the backup driver 106 may not perform power factor correction and / or output current regulation. Excluding such functions from the backup driver 106 may result in the backup driver 106 being robust and having a lower production cost.

[0024] Because the backup driver 106 has higher power surge protection than the primary driver 104, it is designed to provide power to the light source 110 when the primary driver 104 fails due to an input power surge, even though both the primary driver 104 and the backup driver 106 are exposed to the same input power surge. By using the backup driver 106 to power the light source 110, the redundant lighting driver system 102 enables the lighting system 100 to continue providing light when the primary driver 104 fails or is disabled. The lighting system 100 can continue to provide light after the primary driver 104 fails, even while the primary driver 104 is being repaired or replaced.

[0025] In some example embodiments, the redundant lighting driver system 102 can provide power to one or more other light sources besides light source 110. In some alternative embodiments, one or more components other than diodes 112, 114, capable of automatically switching between primary driver 104 and standby driver 106 to power light source 110, can be used without departing from the scope of this disclosure. In some alternative embodiments, the lighting system 100 may include components different from... Figure 1 The components shown are provided without departing from the scope of this disclosure. In some alternative embodiments, the redundant lighting driver system 102 may include, in addition to Figure 1 Other components shown may be used without departing from the scope of this disclosure. In some alternative embodiments, components of the lighting system 100 may be connected in a different configuration than shown without departing from the scope of this disclosure.

[0026] Figure 2 It shows Figure 1 The lighting system 100 illustrates some details of a redundant lighting driver system 102 according to an example embodiment. (See reference...) Figure 1 and Figure 2 In some example embodiments, the backup driver 106 may include an inductor unit 202, a rectifier 204, and a capacitor 206. The inductor unit 202 is electrically coupled to a power supply 108 to receive an AC voltage V from the power supply 108. INAs described above, when no other voltage is introduced in the line connection between the AC power supply 108 and the redundant lighting driver system 102, the input voltage V I It can be basically related to AC voltage V IN same.

[0027] In some example embodiments, the inductor unit 202 is also coupled to the rectifier 204. For example, the rectifier 204 may be as follows: Figure 2 The bridge rectifier shown may be another type of rectifier without departing from the scope of this disclosure. The reverse rated voltage of rectifier 204 may be, for example, 1000 volts. Rectifier 204 can respond to a voltage V from inductor unit 202. O Rectification is performed, as will be readily understood by those skilled in the art who will benefit from the scope of this disclosure. The rectifier 204 may also be coupled to a capacitor 206. For example, capacitor 206 may be a direct current (DC) capacitor rated at 200% of the forward voltage of the LED(s) of the light source 110. Current I DC2 Provided by the backup driver 106 through node 208 connecting the rectifier 204 and the capacitor 206, as Figure 2 As shown. For illustration, node 208 is coupled to the anode of diode 114, causing current I... DC2 The light source 110 is supplied through diode 114.

[0028] In some example embodiments, the inductor unit 202 is designed to have an inductance L that carries the current I from the backup driver 106. DC2 Limit to a current I below that from the main driver 104 DC1 So that when the current I DC1 When available, diode 114 is reverse biased and diode 112 is forward biased. When current I... DC1 When unavailable, for example, because the main driver 104 is subjected to input voltage V I The transient surge damage caused diode 114 to become forward biased and diode 112 to become reverse biased, resulting in a current I... DC2 It is provided to light source 110.

[0029] To illustrate, the voltage V between inductor unit 202 and rectifier 204... O Related to the forward voltage of the LEDs in light source 110 (i.e., the forward voltage of the (multiple) LEDs in light source 110). The rms current I through inductor unit 202. rms With current I DC2 Regarding the current I, when diode 114 is forward biased and diode 112 is reverse biased, DC2 With the current I passing through the light source 110 DCThey are the same. Equation 1 below illustrates this relationship:

[0030]

[0031] Equation 2 below shows the rms current I through inductor unit 202. rms The relationship between the inductance L of inductor unit 202 and:

[0032]

[0033] For the purpose of equation 2, V IN -V O The voltage V across inductor unit 202 is represented by... L And in the absence of voltage spikes / power surges, the AC voltage V IN It can be determined by the input voltage V I Instead. From equations 1 and 2, it can be seen that the current I through light source 110... DC It is AC voltage V IN The function, when the standby driver 106 supplies power to the light source 110, the current I DC With current I DC2 The same. For example, AC voltage V IN The voltage can vary between 120 volts and 277 volts. The inductor unit 202 can be designed or selected to have an inductance L, which causes a current I when the main driver 202 is operating normally. DC2 Less than the current I provided by the main driver 202 DC1 .

[0034] In some example embodiments, the AC voltage V at its maximum level (e.g., 277 volts) can be used as a basis. IN The value of inductance L is selected / determined relative to equations 1 and 2. An inductor component having an inductance value determined based on equations 1 and 2 can be selected as inductor unit 202, where the AC voltage V... IN It is set to the maximum level (e.g., 277 volts). Although when the input voltage V... IN When the voltage level is lower than the maximum level, based on the AC voltage V IN The maximum level selection / determination of the inductor L value can result in a reduction in the current I. DC2 And the dimmer light, but with reduced current I. DC2 The light source 110 can still emit a sufficient level of light. By automatically supplying power to the light source 110 after exposure to a power surge that has disabled the main driver 104, the backup driver 106 enables the lighting system 100 to continue providing light.

[0035] In some alternative embodiments, the backup drive 106 may include, except for Figure 2 Components other than those shown are included without departing from the scope of this disclosure. In some alternative embodiments, components of the backup driver 106 may be connected in a different configuration than shown without departing from the scope of this disclosure. In some alternative embodiments, the backup driver 106 may be implemented as multiple components without departing from the scope of this disclosure.

[0036] Figure 3 An example embodiment is shown. Figure 2 The input voltage V at the input terminal of the backup driver 106 of the redundant lighting driver system 102 I The curve graph. (Refer to...) Figures 1 to 3 In some example embodiments, the input voltage V at the input terminal of the redundant lighting driver system 102 is... I And therefore the input voltage V at the input terminal of the backup driver 106 I This may include the AC voltage V applied from the AC power supply 108. IN Transient voltage surge 302. For example, transient voltage surge 302 could be the result of a lightning strike hitting the line connection between the municipal power supply and the lighting system 100. Inductor unit 202 (e.g., at AC voltage V) IN The input voltage V at inductor unit 202, which has an inductance L of 167mH at 60Hz, is... I It can reach, for example, approximately 10,000 volts, and can have a duration of, for example, approximately 0.01 milliseconds (ms). Following the duration of the transient voltage surge 302, the input voltage V... I Returning to AC voltage V in the range of approximately 120 volts to 277 volts. IN The voltage level decreases, and the inductor voltage across inductor unit 202 decreases accordingly. Figure 3 In the middle, although the input voltage V I It appears to be zero due to the relatively large voltage spike, but the input voltage V I The amplitude ranges from approximately 120 volts to 277 volts.

[0037] In some alternative embodiments, the peak amplitude of the voltage spike may be greater than or less than the amplitude shown, without departing from the scope of this disclosure. In some alternative embodiments, the duration of the voltage spike may be greater than or less than the duration shown, without departing from the scope of this disclosure. In some alternative embodiments, the AC voltage V IN It can be within a range of greater than 277 volts or less than 120 volts, without departing from the scope of this disclosure.

[0038] Figure 4 The DC voltage V according to an example embodiment is shown. DC The curve of the DC voltage V DC It is by Figure 3 The transient voltage surge shown causes the output voltage V of the backup driver 106 to be... DC2 The increase. In Figure 4 The figure shows the DC voltage V when no load is attached to the standby driver 106. DC (i.e., open-circuit voltage). Reference Figures 1 to 4 In some example embodiments, because the inductor unit 202 will come from Figure 3 The energy of the transient voltage surge 302 shown reaches the output voltage V instantaneously. DC2 Slowed down, so the output voltage V of the backup driver 106... DC2 The increase, that is, Figure 4 The DC voltage V shown DC This is significantly lower than the amplitude of transient voltage surge 302. For example, as Figure 4 As shown, even without a load attached to the standby driver 106, the DC voltage V DC It's also approximately 18.5 volts, which is the output voltage V of the backup driver 106. DC2 Regarding the acceptable voltage increase for component failure, despite relatively large transient voltage surges 302. (e.g.) Figure 2 As shown, when a load (e.g., light source 110) is attached to the standby driver 106, the output voltage V of the standby driver 106 is... DC2 The load (e.g., diode 114 and light source 110) is clamped, thereby limiting the DC voltage V. DC By reducing the output voltage V of the backup driver 106 DC2 With the addition of inductor unit 202, transient voltage surge 302 can prevent damage to light source 110 and other components of lighting system 100.

[0039] exist Figure 3 and Figure 4 In this disclosure, the voltage and time values ​​are illustrative examples and may have other values ​​(i.e., higher or lower values) without departing from the scope of this disclosure. Figure 4 In the present disclosure, without departing from the scope of this disclosure, the forward voltage V F It can stabilize at the normal operating voltage level at a rate that is faster or slower than suggested by the graph.

[0040] Figure 5 The example embodiment is shown in the corresponding Figure 2 The inductor 500 is part of the inductor unit 202. For example, the inductance of inductor 500 is the same as the inductance L of inductor unit 202. In some example embodiments, inductor unit 202 includes inductor 500 and other components. See also Figure 2 and Figure 5In some example embodiments, the inductor 500 may include a coil 502 wound around a magnetic core 504. The turns of the coil 502 may be separated by inter-turn insulators T, and the different layers of the coil 502 may be separated by inter-layer insulators. Inter-turn and inter-layer insulation reduces the risk of discharge within the coil 502, which would otherwise cause a failure. The opposite ends of the coil 502 serve as the input and output connections of the inductor 500. For example, the input voltage V... I It can be provided to the first terminal line In, and Figure 2 The voltage V shown O It can be available and supplied at the other end (line Out) of coil 502. Figure 2 The rectifier 204 is shown. The inductance of inductor 500 can depend on several parameters, including the number of turns of coil 502, the size of coil 502, etc., as will be readily understood by one of ordinary skill in the art who will benefit from the scope of this disclosure. For example, inductor 500 can be designed to withstand transient voltage surges of 40 kV or higher.

[0041] In some alternative embodiments, the inductor 500 may have the same characteristics as... Figure 5 Different structures are shown without departing from the scope of this disclosure. In some alternative embodiments, the inductor 500 may include other elements without departing from the scope of this disclosure.

[0042] Figure 6 The example embodiment is shown in the corresponding Figure 2 The transformer 600 is part of the inductor unit 202. For example, the inductance of the transformer 600 is the same as the inductance L of the inductor unit 202. In some example embodiments, the inductor unit 202 includes the transformer 600 and other components. See also Figure 2 and Figure 6 In some example embodiments, transformer 600 may include a primary coil 602 and a secondary coil 604 wound around respective sections of a magnetic core 608. The primary coil 602 and secondary coil 604 are separated from each other by an air gap, which may be partially occupied by an air gap spacer or a magnetic shunt 606. The resulting leakage inductance serves as the inductance of transformer 600. The leakage inductance can depend on many factors, such as the spacing between the primary coil 602 and secondary coil 604, the air gap spacer, or the magnetic shunt 606, etc., as will be readily understood by those skilled in the art who benefit from the scope of this disclosure. Input voltage V I The input connection line In can be provided to the primary coil 602 of the transformer 600, and Figure 2 The voltage V shown O It can be used and provided at the output connection line Out of the secondary coil 604 of transformer 600. Figure 2 The rectifier 204 shown is shown.

[0043] In some example embodiments, transformer 600 may be a step-up or step-down transformer based on windings of primary coil 602 and secondary coil 604, as will be readily understood by those skilled in the art who benefit from the scope of this disclosure. In some example embodiments, transformer 600 may include taps (not shown) for selecting between different input and output voltage relationships, as will be readily understood by those skilled in the art who benefit from the scope of this disclosure.

[0044] In some alternative embodiments, the transformer 600 may have the same characteristics as... Figure 6 Different structures are shown without departing from the scope of this disclosure. In some alternative embodiments, transformer 600 may include other components without departing from the scope of this disclosure.

[0045] Although specific embodiments have been described in detail herein, these descriptions are by way of example. The features of the exemplary embodiments described herein are representative, and in alternative embodiments, certain features, elements, and / or steps may be added or omitted. Furthermore, those skilled in the art can make modifications to various aspects of the exemplary embodiments described herein without departing from the scope of the appended claims, which are consistent with the broadest interpretation to cover modifications and equivalent structures.

Claims

1. A redundant lighting driver system (102), comprising: Main drive (104); A backup driver (106) includes an inductor unit (202) that limits the current that varies over time, wherein the size of the inductor unit (202) is determined such that the backup driver can withstand a transient surge voltage with a duration of less than 1000 μs when supplying power to the light source (110) and the output voltage provided by the backup driver is less than the output voltage provided by the main driver. The primary driver and the backup driver are each configured to receive AC power from a power supply (108), wherein the inductor unit (202) receives the AC power for the backup driver; and The main driver is configured to provide main power to the light source, and the backup driver is configured to provide backup power to the light source when the main driver is disabled due to a power surge, wherein the backup power is less than the main power.

2. The redundant lighting driver system according to claim 1, wherein the inductor unit comprises a step-up transformer or a step-down transformer.

3. The redundant lighting driver system according to claim 1, wherein the backup driver (106) further includes a capacitor (206) and a rectifier (204).

4. The redundant lighting driver system of claim 3, wherein the rectifier is coupled to the inductor unit and the capacitor at node (208) of the standby driver.

5. The redundant lighting driver system of claim 3, wherein the capacitor has a rated voltage that is at least 200% of the forward voltage of one or more light-emitting diodes (LEDs) of the light source.

6. The redundant lighting driver system according to claim 1, further comprising: A first diode (112) and a second diode (114), wherein the anode of the first diode is coupled to the main driver, wherein the anode of the second diode is coupled to the backup driver, and wherein the cathodes of the main driver and the backup driver are coupled to each other at a node designed to be coupled to the light source (110) to provide the main power or the backup power to the light source, and wherein the backup driver provides power to the light source when the voltage at the anode of the second diode is higher than the voltage at the anode of the first diode.

7. The redundant lighting driver system of claim 1, wherein the backup driver does not include a battery and is not connected to a battery.

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