CN101715271A - Emergency ballast system - Google Patents

Abstract

An emergency ballast system is provided. The emergency ballast system includes a ballast unit with a DC/AC inverter. The system also includes a signal preparation unit and an emergency unit. The ballast unit is used to supply power to loads connected to the emergency ballast system by using the common power supply when the normal power supply is working normally. The signal preparation unit is connected to the normal power supply for detecting the working condition of the normal power supply, generating a detection signal reflecting the working condition of the normal power supply and outputting the detection signal to the emergency unit. The emergency unit includes an emergency power supply module. When the normal power source fails, the emergency unit is configured to supply power to the DC/AC inverter using the emergency power source connected to the emergency unit in response to a detection signal reflecting the failure.

Description

Emergency Ballast System

technical field

The present invention relates to emergency ballast systems.

Background technique

Current ballast systems for emergency lighting, such as that of fluorescent lighting fixtures, are often very complex. These systems often include an emergency ballast in addition to the normal ballast. FIG. 1 shows a prior art emergency ballast system 1 . As shown in FIG. 1 , the emergency ballast system 1 includes an emergency ballast 10 and an ordinary ballast 20 . The wiring of the emergency ballast 10 and the normal ballast 20 on the output side allows the lamp to be fully switched from being powered by the normal ballast 20 to being powered by the emergency ballast 10 or from being powered by the emergency ballast 10 To be powered by common ballast 20 . In an emergency, the emergency ballast 10 utilizes the battery 30 to drive the lamp. In most cases, relays are used to achieve the above switching.

In the scheme shown in Figure 1, the wiring from the two ballasts to the lamp is very complicated, resulting in a high probability of miswiring. Furthermore, the varying capacitance of the output wiring to the lamp unit can cause electromagnetic interference. Also, each type of lamp requires a dedicated emergency ballast to keep the lamp operating within its specifications (general purpose emergency ballasts generally do not keep the lamp working properly and cause the lamp to fail more quickly). In addition, the emergency ballast and the general ballast each require an inverter for high-frequency operation of the lamp, thereby making the system cost high. Furthermore, in this solution it is almost impossible to use an emergency ballast in parallel with a dimmable ballast due to the high sensitivity to the capacitance of the wiring in the dimmable application.

Contents of the invention

The present invention provides an emergency ballast system that solves one or more of the problems of prior art solutions or other problems.

According to one embodiment of the present invention, an emergency ballast system is provided. The emergency ballast system includes a ballast unit with a DC/AC inverter. The system also includes a signal preparation unit and an emergency unit. The ballast unit is used to supply power to loads connected to the emergency ballast system by using the common power supply when the normal power supply is working normally. The signal preparation unit is connected to the normal power supply for detecting the working condition of the normal power supply, generating a detection signal reflecting the working condition of the normal power supply and outputting the detection signal to the emergency unit. The emergency unit includes an emergency power supply module. When the normal power source fails, the emergency unit is configured to supply power to the DC/AC inverter using the emergency power source connected to the emergency unit in response to a detection signal reflecting the failure.

Some embodiments of the present invention will be described below with reference to the accompanying drawings. The objects, features and advantages of the present invention will be better understood from the following description.

Description of drawings

FIG. 1 is a schematic diagram showing a prior art emergency ballast system;

Figure 2 is a schematic diagram illustrating an emergency ballast system according to one embodiment of the present invention;

FIG. 3 is a schematic diagram showing an emergency ballast system according to another embodiment of the present invention; and

FIG. 4 is a schematic diagram showing an emergency ballast system according to another embodiment of the present invention.

Detailed ways

Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the interest of clarity and conciseness, not all features of an actual implementation are described in the specification. However, it should be understood that in proceeding with any such actual implementation, a number of implementation-specific decisions must be made in order to achieve the developer's goals, such as compliance with various system-related and business-related constraints , and these constraints vary across implementations. Moreover, it will be appreciated that such an implementation effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art, given the present disclosure.

FIG. 2 illustrates an emergency ballast system 100 according to one embodiment of the present invention. The emergency ballast system 100 includes an emergency unit 110 , a ballast unit 120 and a signal preparation unit 130 . The ballast unit 120 includes a DC/AC inverter 121 , while the emergency unit 110 includes an emergency power module 111 .

As shown, the ballast unit 120 is connected to a common power source via wires L1 and N. The ballast unit 120 utilizes the normal power supply to power one or more loads (one load is illustrated in the figure) connected to the emergency ballast system when the normal power supply is operating normally.

The signal preparation unit 130 is connected to a common power source through a wire L2, and is used to detect the working condition (for example, voltage) of the power source. In addition, the signal preparation unit 130 may generate a detection signal reflecting the working condition of the common power supply, and output the detection signal to the emergency unit 110 and/or the ballast unit 120 .

The detailed structure of the signal preparation unit 130 is omitted here. Those skilled in the art can understand that any structure capable of detecting the working condition (such as voltage) of the power supply, generating and outputting a signal reflecting the working condition can be used in the signal preparation unit. For example, the signal preparation unit may be a conversion unit for converting a high voltage line signal into a small signal, preferably a direct current DC signal, used as a drive signal for logic in an AC/DC inverter. In one embodiment, the signal preparation unit may be a voltage divider with rectification and output filter. Of course, those skilled in the art can understand that the signal preparation unit according to the present invention is not limited to the above examples and embodiments.

In a normal operating condition in which the inverter 121 of the ballast unit 120 supplies power to a load connected to the emergency ballast system using power from a common power source, in response to a detection signal generated by the signal preparation unit 130 reflecting the normal operating condition, The emergency power supply module 111 is turned off, and the output of the DC/AC inverter 121 is regulated to a rated value.

When a general power source fails, the signal preparation unit 130 detects the failure, and generates a detection signal reflecting the failure. In response to the detection signal reflecting the fault, the emergency power module 111 of the emergency unit 110 is turned on, so that the emergency unit 110 can use the emergency power connected to the emergency unit 110 to supply power to the inverter 121 . Additionally, in response to the detection signal reflecting the fault, the output of the DC/AC inverter 121 may optionally be adjusted to a lower value in order to reduce consumption of energy provided by the emergency power supply. At the same time, the emergency power supply module 11 can charge the bus voltage capacitor 122 connected between the input terminals of the DC/AC inverter 121 to a level required for normal operation of the DC/AC inverter 121 .

The bus voltage capacitor 122 is part of the ballast to which energy from an external source must be supplied to keep the inverter running in an emergency.

When the general power supply recovers from the failure, the signal preparation unit 130 detects the recovery, and generates a signal reflecting the recovery. In response to this signal, the emergency power supply module 111 is turned off, and the output of the DC/AC inverter 121 is regulated to a nominal value.

It can be seen that the emergency unit 110 in this embodiment is different from the emergency ballast 10 shown in FIG. 1 in that the emergency unit 110 does not include an inverter for lamp operation. That is, in the event of failure of the normal power supply, the inverter 121 in the normal ballast unit 120 is still used to drive the load (such as a lamp).

This technical solution requires no special wiring or switches on the output side of the emergency ballast system. The basic idea is that the emergency unit shares useful circuit parts in common ballasts for common operation.

FIG. 3 shows an emergency ballast system 200 according to another embodiment of the present invention.

As shown in FIG. 3 , the emergency ballast system 200 includes an emergency unit 210 and a ballast unit 220 . The ballast unit 220 includes an APFC (Active Power Factor Correction) or PPFC (Passive Power Factor Correction) module 223 , a DC/AC inverter 221 and a signal preparation module 230 . The emergency unit 210 includes a DC/DC power supply module 211 and a DC/DC battery charger 212 .

In some embodiments, both the DC/DC power module 211 and the DC/DC battery charger 212 can use known DC/DC circuit topologies, such as boost converter, flyback converter, single-ended primary inductance converter (SEPIC) or buck-boost converter, etc. For the DC/DC power module 211, preferably a boost converter is used, alternatively, a SEPIC may be used. For the DC/DC battery charger 212, preferably a flyback converter or a buck-boost converter can be used. Although some examples of the above two modules are described herein, those of ordinary skill in the art will recognize that any structure capable of performing the functions of the two modules described herein may be used. That is, the two modules according to the invention are not limited to the specific embodiments and examples described herein.

In this embodiment, the function of the signal preparation module 230 is the same as that of the signal preparation module 130 shown in FIG. 2 . The structure of the emergency ballast system 200 is similar to the structure of the emergency ballast system 100 shown in FIG. 2 , the difference is that in the embodiment shown in FIG. . Additionally, a switch S is used on line L1 to switch the ballast unit on or off.

In this embodiment, the emergency power source connected to the emergency unit is a battery. The emergency unit 210 maintains the energy of the battery and supplies power to the inverter 221 of the ballast unit 220 in an emergency situation independently of the normal power source (such as the power line). Of course, those of ordinary skill in the art should realize that the emergency power supply can also be other types of available power supplies other than batteries.

In the ballast unit 220, the bus voltage capacitor 222 is the most suitable component for charging the battery. This capacitor 222 is in turn adapted to store energy for the inverter in the ballast. As shown in Figure 3, the bus voltage capacitor 222 is connected between the two input terminals of the inverter in the ballast. Additionally, one pole of the bus voltage capacitor 222 is connected to the emergency unit 210 and the other pole is connected to the ground of the ballast.

Additionally, the bus voltage capacitor 222 is one component of the ballast that must be powered from an external source to keep the inverter running in an emergency. In this embodiment, the bus voltage capacitor (also known as the Bus E-cap) may be charged by the APFC or PPFC to a relatively stable specific voltage (e.g., typically 200-500V for power line applications), whereby the capacitor Can store energy for DC/AC inverters. Additionally, the bus voltage capacitor can also be used as an energy source for a DC/DC battery charger as described above.

Similarly, under normal operating conditions in which the inverter 221 of the ballast unit 220 powers the lamp with power from the power line, the DC/DC battery charger 212 responds to a signal generated by the signal preparation module reflecting the normal operating condition L2i is turned on so that the battery charger 212 uses the energy available in the bus voltage capacitor 222 to charge the battery. At the same time, in response to the signal L2i reflecting the normal working condition, the DC/DC power module 211 is turned off, and the output of the DC/AC inverter 221 is adjusted to a rated value.

In the case of failure of the common power source (power line in this embodiment), for example, when the power line loses voltage, the signal preparation module 230 detects the failure and generates a signal L2i reflecting the failure. In response to the signal L2i reflecting the failure, the DC/DC battery charger 212 is turned off, the DC/DC power supply module 211 is turned on, and the output of the DC/AC inverter 221 is lowered to a lower level, In order to reduce the consumption of energy provided by the battery. By reducing the output power of the inverter, the working time of the emergency ballast system can be greatly extended. At the same time, the DC/DC power module 211 charges the bus voltage capacitor 222 to a level required for the normal operation of the DC/AC inverter 211 .

When the power line recovers from the fault, the signal preparation module 230 detects the recovery and generates a signal reflecting the recovery. In response to a signal reflecting this restoration, the DC/DC power supply module 211 is turned off, and the output of the DC/AC inverter 221 is adjusted to a rated value.

FIG. 4 shows an emergency ballast system 300 according to another embodiment of the present invention. The structure of the emergency ballast system 300 is similar to the emergency ballast system 200 shown in FIG. 3 , the difference is that in this embodiment, the signal preparation module is integrated in the emergency unit. In this case, the signal preparation module must be connected directly to the common power source (power line in this embodiment) without any switches. The operation of the emergency ballast system 300 is the same as that of the emergency ballast system 200 shown in FIG. 3 , and will not be repeated here.

In the above embodiments, the ballast unit is an electronic ballast.

It can be seen that in the above embodiments, the wiring between the emergency ballast system and the load (such as a lamp) is very simple, and there is no need to change the original wiring between the ballast and the load. This simple output wiring reduces electromagnetic interference compared to the prior art solution shown in FIG. 1 .

Additionally, with an emergency ballast system according to an embodiment of the present invention, no dedicated emergency ballast is required.

In addition, the emergency unit in the emergency ballast system according to the embodiment of the present invention does not include an inverter, thereby reducing the cost of the system.

In addition, in the technical solution of the present invention, the output level of the inverter of the ballast can be adjusted in response to the signal reflecting the working condition of the common power supply.

Also, dimmable ballasts can be used in the present invention.

Although the present invention has been described based on some preferred embodiments, those skilled in the art should understand that these embodiments should not be construed as limiting the scope of the present invention. Without departing from the spirit and scope of the present invention, any changes or modifications to the described embodiments within the understanding of those skilled in the art fall within the scope of the present invention defined by the appended claims .

Claims (13)

1. An emergency ballast system (100, 200, 300) comprising a ballast unit (120, 220, 320) having a DC/AC inverter (121, 221, 321), the ballast unit Used to supply power to loads connected to the emergency ballast system by using the common power supply when the normal power supply is working normally, the system is characterized by further comprising a signal preparation unit (130, 230, 330) and an emergency unit (110, 210 , 310), The signal preparation unit (130, 230, 330) is connected to the common power supply, and is used for detecting the working condition of the common power supply, generating a detection signal reflecting the working condition of the common power supply and outputting the detection signal to the emergency unit, The emergency unit (110, 210, 310) includes an emergency power supply module (111, 211, 311), wherein when the normal power supply fails, the emergency power supply module utilizes a connection An emergency power source to the emergency unit powers the DC/AC inverter. 2. The emergency ballast system according to claim 1, characterized in that the output of the DC/AC inverter (121, 221, 321) is The level is adjusted to a rated level, and the output level of the DC/AC inverter (121, 221, 321) is adjusted to be less than the rated level in response to a detection signal reflecting a failure of the common power supply. flat level. 3. The emergency ballast system according to claim 1 or 2, characterized in that, the ballast unit (120, 220, 320) further comprises a bus voltage capacitors (122, 222, 322), said emergency power supply module (111, 211, 311) being adapted to charge said bus voltage capacitors to said DC/AC inverter in the event of failure of said normal power supply level required for proper operation. 4. The emergency ballast system according to claim 1 or 2, characterized in that, the signal preparation unit (130, 230, 330) is also used to detect the voltage on the common power supply, so as to detect the normal power supply working status. 5. The emergency ballast system according to claim 1 or 2, characterized in that the emergency power source is a battery. 6. The emergency ballast system according to claim 5, characterized in that, the emergency unit (110, 210, 310) further comprises a battery charger module (112, 212, 312), which is used for The battery is charged in response to a detection signal reflecting a normal operating condition of the common power supply, and charging of the battery is stopped in response to a detection signal reflecting a failure of the common power supply. 7. The emergency ballast system according to claim 1 or 2, characterized in that the signal preparation unit (130, 230, 330) is integrated with the emergency unit (110, 210, 310). 8. The emergency ballast system according to claim 1 or 2, characterized in that the signal preparation unit (130, 230, 330) is integrated with the ballast unit (120, 220, 320). 9. The emergency ballast system according to claim 1 or 2, characterized in that the ballast unit (120, 220, 320) is an electronic ballast. 10. The emergency ballast system according to claim 1 or 2, characterized in that the load is a lamp. 11. The emergency ballast system according to claim 1 or 2, characterized in that the common power source is a power line. 12. The emergency ballast system according to claim 1 or 2, characterized in that, the emergency power module (111, 211, 311) is a DC/DC power module, and the power module is a boost converter, a flyback converter, single-ended primary inductor converter, or buck-boost converter. 13. The emergency ballast system of claim 6, wherein the battery charger module (112, 212, 312) is a boost converter, a flyback converter, a single-ended primary inductance converter or One of the buck-boost converters.

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