KR101169738B1 - Power Supply Equipped with Electric Safety Function for Lighting System - Google Patents

Abstract

According to a power supply device of a preferred embodiment of the present invention, in order to prevent an accident such as a malfunction or a fire due to overheating of an illumination light source such as an LED, an electrical safety that prevents the illumination light source from overheating by using temperature information by a temperature sensor. It is possible to supply a power supply with a function. In addition, according to the present invention can detect a leakage current and ground fault of the power supply for the illumination light source to provide a power supply with an electrical safety function that can prevent electric fire and electric shock.
According to an embodiment of the present invention, a power supply device includes: a power supply unit for receiving an AC signal, converting the signal into a DC signal, and supplying the DC signal to an illumination light source; At least one of a temperature signal from a temperature sensor for contacting the illumination light source or a predetermined distance from the illumination light source and measuring a temperature of the illumination light source, an output voltage signal of the power supply unit, and an output current signal; A PWM controller for controlling an output voltage and an output current of the power supply unit to be supplied to the illumination light source to adjust a duty ratio of the output signal of the PWM controller; .

Description

Power Supply Equipped with Electric Safety Function for Lighting System

The present invention relates to a power supply having an electrical safety function, and more particularly to a power supply having an electrical safety function for a lighting system using a pulse width modulation (PWM) control method.

In order to reduce environmental pollution, power consumption can be reduced by using LED elements (packages, modules, etc.) instead of sodium, metal halides, mercury lamps, incandescent lamps, and halogen lamps, which are widely used as light sources of existing lighting equipment. . LEDs have many advantages, such as long life, low power consumption, and high reliability, but there are also many disadvantages. In particular, the urgent task to be developed in LED lighting technology is to complement heat dissipation technology. The LED itself is vulnerable to heat, and if the circuit board made of plastic is exposed to hot air for a long time, it may be easily damaged, which may cause damage due to insulation deterioration.

In general, the LED lighting equipment receives AC 220V power and converts it into DC power through an AC-DC converter, and then supplies the LED lamp (LED module) to light the lamp (but, AC power supply). Some LED lamps have been developed).

AC-DC converters, a common component of LED lighting installations, mainly use Switched Mode Power Supply (SMPS), which has advantages of high energy efficiency and small size and light weight. As shown in Fig. 2, the SMPS system is a DC-DC converter which converts a DC input voltage obtained from an AC input power source through an input rectification smoothing circuit to a DC output voltage, and a feedback control circuit that stabilizes the output voltage, an overvoltage, an overcurrent system, and the like. It consists of a protection circuit to protect. The feedback control circuit is composed of an error amplifier which amplifies the error of the output voltage again, a comparator which compares the amplified error with a triangular wave to generate a driving pulse, and a driving circuit which drives the main switch of the DC-DC converter. The DC converter consists of a main switch, a freewheeling diode, and an LC filter, a secondary low pass filter.

Among the components of SMPS, DC-DC converter is the main part responsible for power conversion, and it is classified into many kinds of converters according to the size of input / output change ratio and circuit configuration. SMPS circuit can be divided into non-isolated (Buck, Boost, Buck-boost, C'uk, etc.) and isolated (Flyback, Forward, Full-bridge, Half-bridge, etc.) depending on the presence of high frequency transformer. have. However, insulated type and non-isolated type have the difference of electrical insulation between input and output to protect the user from accidents due to high voltage or leakage current in SMPS application, but the basic characteristics have the same constant voltage characteristics. have. In addition, in recent years, an effective control technique has been applied to increase the efficiency and life of the LED lamp through the constant current control instead of the constant voltage control for driving the LED lamp.

  However, if power is supplied by a normal SMPS, there is no problem. However, when overpower is supplied, the LED module emits brighter light, but the lifespan is drastically reduced and there is a risk of fire. Because of these shortcomings, SMPS has been recently applied to the constant current and constant voltage controller methods.However, if an error occurs in the variable resistor or output port for setting the output voltage of the SMPS, the SMPS does not cause much damage, but the voltage supplied to the LED module may increase. In this case, since a fire accident frequently occurs due to the supply current or heat generation from the LED lamp, a countermeasure is required (see FIG. 3).

In addition, in case of SMPS, when leakage current and ground fault occur, an electric fire and an electric shock may occur. In the case of LED power supply, such leakage current and ground state should be detected and appropriately controlled.

The present invention has an object to solve the technical problem as described above, the illumination light source using the temperature information by the temperature sensor in order to prevent an accident such as malfunction and fire due to overheating of the illumination light source such as LED Its purpose is to provide a power supply with an electrical safety function that does not overheat.

It is also an object of the present invention to provide a power supply having an electric safety function capable of detecting leakage currents and ground faults of the power supply for an illumination light source and preventing an electric fire and an electric shock.

Power supply device having an electrical safety function for a lighting system according to an embodiment of the present invention includes a power supply for receiving an AC signal converted to a DC signal to supply to the illumination light source; And a temperature signal from a temperature sensor for contacting the illumination light source or within a predetermined distance from the illumination light source and measuring a temperature of the illumination light source, an output voltage signal of the power supply unit, and an output current signal. A PWM controller which receives a signal and controls an output voltage and an output current of the power supply unit to be supplied to the illumination light source to adjust a duty ratio of an output signal of the PWM controller; It includes.

In addition, the power supply apparatus according to the present invention, the constant voltage control unit for controlling the output voltage of the power supply to a constant level by detecting the output voltage of the power supply and input to the PWM control unit; Or a constant current controller for controlling the output current of the power supply to a predetermined level by detecting the output current of the power supply and inputting the output current to the PWM controller.

Specifically, the PWM control unit; an overheat control module for determining whether the illumination light source is overheated by the temperature signal from the temperature sensor.

The overheat control module according to an exemplary embodiment, when the temperature signal is less than a predetermined temperature, receives the output voltage signal and the output current signal of the power supply unit and adjusts the output signal by a pulse width modulation method. The output voltage signal and the output current signal of the supply unit is controlled, but when the temperature signal is above a predetermined temperature, the temperature signal is controlled to be below a predetermined temperature by adjusting the output signal by a pulse width modulation method. .

The PWM control unit may further include a temperature signal preprocessing module configured to perform signal processing and control of the temperature signal from the temperature sensor in the overheat control module.

In addition, the temperature signal preprocessing module according to a preferred embodiment, the signal amplifier for amplifying the temperature signal from the temperature sensor; A reference temperature setter for setting a reference temperature for judging whether to overheat; And a comparator for determining whether a temperature signal from the temperature sensor is equal to or higher than a reference temperature set by the reference temperature setter. And a control unit.

The PWM controller may further include a leakage and ground fault control module configured to detect and control a leakage current and a ground fault state of the power supply by an output voltage signal or an output current signal from the power supply.

Specifically, the output control of the power supply unit according to the detection and detection of the leakage current and the ground fault state of the power supply device by the leakage and ground control module is proportional control, proportional-integral control, proportional-derived control, proportional-integrated- One of the derivative control techniques may be used, and the four control techniques measure an output value of an object to be controlled in the form of a feedback controller, and compare the measured output value with a preset reference value to obtain an error value. It calculates and uses the calculated error value.

The leakage and ground fault control module according to an exemplary embodiment may include a first error value preset by comparing a signal level of a negative terminal of an output voltage signal or an output current signal of the power supply unit with a first preset reference value. A first determiner for determining whether the above difference occurs; The difference between the signal level of the positive terminal and the negative terminal of the output voltage signal or the output current signal of the power supply unit is different from the preset second error value by comparing with the preset second reference value. A second determiner for determining whether to perform; And comparing a signal level of the positive terminal of the output voltage signal or the output current signal of the power supply unit with a third reference value set in advance, and calculating a third error value that is a difference value, and outputting the output voltage signal of the power supply unit or The fourth error value is calculated by comparing the signal level of the negative terminal of the output current signal with the preset fourth reference value, and the fourth error value is compared by comparing the third error value with the fourth error value. A third determiner that calculates a fifth error value, and determines whether a difference greater than or equal to the sixth preset error value occurs by comparing the fifth error value with a preset fifth reference value; It characterized in that it comprises any one or more of the components.

The leakage and ground fault control module determines that a leakage current and a ground fault state of the power supply device have occurred, if a difference greater than the first error value, the second error value, or the sixth error value occurs, and then outputs the power supply part. It is characterized by controlling the voltage to '0'V.

The output signal of the PWM controller of the preferred embodiment is input to the switching element included in the power supply is characterized in that for controlling the output of the power supply.

The PWM controller may further include an alarm function to warn the user when an abnormality occurs in the temperature of the illumination light source, the output voltage from the power supply, and the output current.

According to a power supply device of a preferred embodiment of the present invention, in order to prevent an accident such as a malfunction or a fire due to overheating of an illumination light source such as an LED, an electrical safety that prevents the illumination light source from overheating by using temperature information by a temperature sensor. It is possible to supply a power supply with a function.

In addition, according to the present invention can detect a leakage current and ground fault of the power supply for the illumination light source to provide a power supply with an electrical safety function that can prevent electric fire and electric shock.

1 shows a general configuration diagram of an LED lighting fixture.
2 shows a configuration diagram of an SMPS.
3 shows an example of the burnout of the LED module due to overheating due to the voltage rise.
4 is a block diagram of a power supply having an electric safety function for a lighting system according to an embodiment of the present invention.
5 shows a configuration diagram of a PWM control unit.
6 illustrates an embodiment of an SMPS to which a flyback converter is applied.
7 is a view for explaining the overheat prevention function by the power supply according to an embodiment of the present invention.
8 is a configuration diagram of a temperature signal preprocessing module.
9 is an explanatory diagram of a power supply having a leakage current and ground fault detection and control function according to an embodiment of the present invention.
10 is a configuration diagram of a leakage and ground fault control module.

Hereinafter, a power supply device having an electrical safety function for a lighting system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The following examples of the present invention are intended to embody the present invention, but not to limit or limit the scope of the present invention. What can be easily inferred by those skilled in the art from the detailed description and the embodiments of the present invention is interpreted as belonging to the scope of the present invention.

In addition, in the following description of the present invention, the LED lighting is an embodiment of the illumination light source, and of course, it can be applied to other kinds of illumination light sources as well as LED lighting.

First, Figure 4 shows a block diagram of a power supply equipped with an electrical safety function for a lighting system according to an embodiment of the present invention.

As can be seen from Figure 4, the power supply device 1000 with an electrical safety function for a lighting system according to an embodiment of the present invention is a power supply unit 100, PWM control unit 200, constant voltage control unit ( 300 and the constant current controller 400.

The power supply unit 100 receives an AC signal and converts the signal into a DC signal to supply the illumination light source.

In addition, the PWM control unit 200 is installed in contact with the illumination light source or within a predetermined predetermined distance with the illumination light source, the temperature signal from the temperature sensor for measuring the temperature of the illumination light source, the output of the power supply unit 100 At least one of a voltage signal and an output current signal is input and supplied to the illumination light source by adjusting the duty ratio of the output signal of the PWM controller 200, that is, modulating a pulse width. It characterized in that for controlling the output voltage and output current of the power supply unit 100 to be.

The constant voltage controller 300 and the constant current controller 400 detect the output voltage and the output current of the power supply unit 100 and input the same to the PWM controller 200 to maintain a constant level of the power supply unit 100. It controls the output voltage and output current.

Specifically, the configuration of the PWM control unit 200 will be described. Understanding the configuration of the PWM control unit 200 will be very helpful in understanding the function of the power supply device 1000 of the present invention.

5 shows a configuration diagram of the PWM control unit 200.

As can be seen from Figure 5 PWM control unit 200 according to an embodiment of the present invention is the overheat control module 210 to determine whether the illumination light source is overheated by the temperature signal from the temperature sensor, the temperature Power is supplied by an output voltage signal or an output current signal from the temperature signal preprocessing module 220 and the power supply unit 100 to enable the signal processing and control of the temperature signal from the sensor to the overheat control module 210. And a leakage and ground fault control module 230 for detecting and controlling leakage current and ground fault conditions of the device.

As can be seen from the components of FIG. 5, the power supply device 1000 according to the preferred embodiment of the present invention has two functions of preventing overheating of the illumination light source, leakage current and ground fault detection and control of the power supply device. Equipped.

First, the overheat prevention function of the illumination light source will be described.

Overheating protection of lighting source

The power supply for LED lighting depends on the type of internal DC-DC converter. Types of DC-DC converters include non-isolated Buck, Boost, Buck-boost, and C'uk methods, and the isolated types include Flyback, Forward, Full-bridge, and Half-bridge. Among these various schemes, FIG. 6 shows an SMPS circuit to which a flyback converter, which is commonly used for LED lighting, is applied.

7 is a view for explaining the overheat prevention function by the power supply device 1000 according to an embodiment of the present invention.

As can be seen from Figure 7, the power supply device 1000 according to the present invention is a temperature sensor irrespective of the type of the DC-DC converter inside the SMPS while maintaining the function of the SMPS shown in Figure 6 which is a conventional power supply When an abnormality occurs inside and outside of SMPS by using over power, and the temperature rises due to overpower applied to LED lighting, it detects this and lowers the SMPS output voltage and current to prevent temperature rise. SMPS was designed.

Specifically, for the constant voltage control and the constant current control, the output voltage signal and the output current signal from the constant voltage controller 300 and the constant current controller 400 are input to the PWM controller 200 and fed back to the power supply unit 100.

In addition, the temperature signal of the LED light is also input to the PWM control unit 200 from the outside of the power supply unit 100.

When the temperature signal is less than a predetermined temperature, the overheat control module 210 receives the output voltage signal and the output current signal of the power supply unit 100 and adjusts the output signal by a pulse width modulation method. While controlling the output voltage signal and the output current signal of (100), if the temperature signal is above a certain temperature, by controlling the output signal by a pulse width modulation method, the temperature signal is controlled to be below a certain temperature It is done.

That is, the PWM controller 200 modulates the duty ratio by the voltage signal, current signal, and temperature signal input to the PWM controller 200 and inputs the duty ratio to the switching element 110 of the power supply unit 100.

As can be seen from FIG. 7, in the exemplary embodiment of the present invention, a field effect transistor (FET) is used as the switching element 110, and the output of the PWM controller 200 is input as a drain voltage of the FET.

In addition, the temperature signal preprocessing module 220 may include a signal amplifier 221 for amplifying a temperature signal from the temperature sensor and a reference temperature setter for setting a reference temperature for determining whether overheated. 222, and a comparator 223 for determining whether the temperature signal from the temperature sensor is equal to or higher than the reference temperature set by the reference temperature setter 222.

The setting of temperature data and limit temperature depends on the type of temperature sensor. In the case of the commonly used contact temperature sensor K-Type, since the electromotive force generated according to the temperature is 40 μV / ° C., if the limit temperature of about 100 ° C is set, the input of the signal amplifier 221 of FIG. 8 is 4 mV input. The circuit may be configured as much as possible. However, since a 4mV voltage may not be received as an input in a TTL or CMOS series IC, the signal amplifier 221 is required because the input signal needs to be amplified.

Hereinafter, leakage current and ground fault detection and control functions of the power supply device 1000 according to an exemplary embodiment of the present invention will be described.

Leakage current and ground fault detection and control

In order to design a power supply device for supplying a constant current and a constant voltage, a reference value (or a set value) for the current and voltage to be output and a value for the current and voltage being output are fed back and controlled. In order to control, PID control is generally performed.

The PID controller is a proportional-integral-differential controller and is a representative type of control technique that is most used in practical applications. The PID controller basically has the form of a feedback controller, and measures an output value of an object to be controlled and compares it with a reference value or a setpoint desired to obtain an error. Is calculated and the control value required for control is calculated using this error value.

The standard type PID controller is configured to calculate a control value (MV) by adding three terms as shown in [Equation 1].

Each term in Equation 1 has a name of proportional-integral-derivative controller because it is proportional to an error value, an integral of an error value, and a derivative of an error value. . The intuitive meaning of these three terms is as follows.

-Proportional term: Controls proportional to the magnitude of the error value in the current state.

-Integral term: Eliminates steady-state error.

Derivative term: Braking on abrupt changes in the output value reduces overshoot and improves stability.

The PID controller is used in the form of a standard equation such as [Equation 1], but in some cases, it is used in a slightly modified form. For example, it may be used simply in the form of a controller having only proportional terms, or only proportional-integral and proportional-differential terms, which are called P, PI, and PD controllers, respectively.

9 is an explanatory diagram of a power supply device 1000 having a leakage current and ground fault detection and control function according to an embodiment of the present invention having the PID control function described above. As can be seen from FIG. 9, in contrast to feeding back and controlling information on one output power, it is controlled by feeding back information about a positive output terminal and a negative output terminal of the output power. .

Of the two types of information, like the conventional power supply, the information of the positive output terminal is used for the constant current (constant voltage) control. However, the information on the negative output terminal, together with the information on the positive output terminal, detects the leakage current and the ground state of the power supply 1000 in the leakage and ground control module 230. Used.

10 is a block diagram of the leakage and ground fault control module 230 according to an embodiment of the present invention.

As can be seen from Figure 10 the leakage and ground fault control module 230 according to a preferred embodiment of the present invention, the signal of the negative terminal of the output voltage signal or output current signal of the power supply unit 100 A first determiner 231 for comparing a level with a preset first reference value to determine whether a difference greater than or equal to a preset first error value occurs; The difference value between the signal level of the positive terminal and the negative terminal of the output voltage signal or the output current signal of the power supply unit 100 is greater than or equal to a preset second error value in comparison with a preset second reference value. A second determiner 232 that determines whether a difference occurs; And calculating a third error value that is a difference value by comparing the signal level of the positive terminal of the output voltage signal or the output current signal of the power supply unit 100 with a third reference value preset. Comparing the signal level of the negative terminal of the output voltage signal or the output current signal with the fourth reference value preset, a fourth error value that is a difference value is calculated, and the third error value and the fourth error value are compared. A third determiner 233 that calculates a fifth error value that is a difference value and determines whether a difference greater than or equal to a sixth preset error value occurs by comparing the fifth error value with a preset fifth reference value; It characterized in that it comprises any one or more of the components.

The leakage and ground fault control module 230 determines that a leakage current and a ground fault have occurred in the power supply device, if a difference greater than the first error value, the second error value, or the sixth error value occurs, and then, The output voltage of the supply unit 100 is controlled to '0'V. The method of controlling the output voltage of the power supply unit 100 to '0' V may be performed by inputting the output signal of the PWM controller 200 to the switching element 110 included in the power supply unit 100. have.

In addition, the PWM control unit 200 according to an embodiment of the present invention, when an abnormality occurs in the output voltage and output current due to the temperature of the illumination light source, the leakage current and ground fault from the power supply unit 100, It may include an alarm function to warn the user. In addition, the PWM control unit 200 may perform a function of detecting the abnormality of each module constituting the LED lighting through the analysis of the current signal.

Street lights, security lamps, landscape lights, etc. using LED lighting are composed of several modules in one lamp. An abnormality occurs in one module among these modules, and may cause inconvenience to pedestrians, etc., due to poor illumination, and may interfere in performing an original role of lighting. In addition, if one module among several modules is operated continuously and may cause damage due to overloading the remaining modules, the current data input to the PWM control unit 200 is analyzed to analyze the current data per component module of the LED lighting. The manager can easily check whether the LED module is damaged by analyzing the current consumption, so the manager can check the current abnormality alarm lamp configured in the SMPS by using the current data analysis result. It is designed to.

1000: power supply according to the present invention
100: power supply unit 200: PWM control unit
300: constant voltage control unit 400: constant current control unit
110: switching element
210: overheat control module 220: temperature signal preprocessing module
230: leakage and ground fault control module
221: signal amplifier 222: reference temperature setter
223: comparator
231: first judge 232: second judge
233: third judge

Claims (10)

In the power supply,
A power supply unit which receives an AC signal and converts the signal into a DC signal to supply the illumination light source; And
At least one of a temperature signal from a temperature sensor for contacting the illumination light source or a predetermined distance from the illumination light source and measuring a temperature of the illumination light source, an output voltage signal of the power supply unit, and an output current signal; A PWM controller configured to control an output voltage and an output current of the power supply unit to be supplied to the illumination light source by adjusting a duty ratio of an output signal of the PWM controller; Including,
The PWM control unit,
And a leakage and ground fault control module configured to detect and control a leakage current and a ground fault state of the power supply by an output voltage signal or an output current signal from the power supply.
The leakage and ground fault control module,
A first determiner for comparing a signal level of a negative terminal of an output voltage signal or an output current signal of the power supply unit with a preset first reference value to determine whether a difference greater than or equal to a preset first error value occurs;
The difference between the signal level of the positive terminal and the negative terminal of the output voltage signal or the output current signal of the power supply unit is different from the preset second error value by comparing with the preset second reference value. A second determiner for determining whether to perform; And
Comparing the signal level of the positive terminal of the output voltage signal or the output current signal of the power supply unit and the third reference value set in advance to calculate a third error value that is a difference value, the output voltage signal or output of the power supply unit A fourth error value that is a difference value is calculated by comparing the signal level of the negative terminal of the current signal with a preset fourth reference value, and the fifth error value that is a difference value by comparing the third error value and the fourth error value. A third determiner that calculates an error value and determines whether a difference greater than or equal to a preset sixth error value occurs by comparing the fifth error value with a preset fifth reference value; A power supply with an electrical safety function for a lighting system, characterized in that it comprises any one or more components.
The method of claim 1,
The power supply device,
A constant voltage controller for controlling the output voltage of the power supply to a predetermined level by detecting an output voltage of the power supply and inputting the same to the PWM controller; or
And a constant current controller for controlling the output current of the power supply unit to a predetermined level by detecting an output current of the power supply unit and inputting the output current to the PWM control unit. Power supply.
The method of claim 1,
The PWM control unit,
And an overheat control module configured to determine whether the illumination light source is overheated by the temperature signal from the temperature sensor.
The overheat control module,
When the temperature signal is below a predetermined temperature, the output voltage signal and the output current signal of the power supply unit are input to control the output voltage signal and the output current signal by adjusting the output signal by a pulse width modulation method. ,
When the temperature signal is above a certain temperature, the power supply device with an electrical safety function for a lighting system, characterized in that the control by controlling the output signal by a pulse width modulation method so that the temperature signal is below a certain temperature. .
The method of claim 3, wherein
The PWM control unit,
And a temperature signal preprocessing module that enables signal processing and control of the temperature signal from the temperature sensor in the overheat control module.
The temperature signal preprocessing module,
A signal amplifier for amplifying a temperature signal from the temperature sensor;
A reference temperature setter for setting a reference temperature for judging whether to overheat; And
A comparator for determining whether a temperature signal from the temperature sensor is equal to or greater than a reference temperature set by the reference temperature setter; Power supply with an electrical safety function for a lighting system comprising a.
delete The method of claim 1,
Output control of the power supply unit according to the detection and detection of the leakage current and the ground fault state of the power supply device by the leakage and ground fault control module,
Any one of proportional control, proportional-integral control, proportional-differential control and proportional-integral-derived control techniques may be used, and the four control techniques are output values of an object to be controlled in the form of a feedback controller. And measuring the output value and comparing the measured output value with a preset reference value to calculate an error value, and using the calculated error value.
delete The method of claim 1,
The leakage and ground fault control module determines that a leakage current and a ground fault state of the power supply device have occurred, if a difference greater than the first error value, the second error value, or the sixth error value occurs, and then outputs the power supply part. Power supply with electrical safety for lighting systems, characterized in that the voltage is controlled to '0'V.
The method of claim 1,
The output signal of the PWM control unit is input to the switching element included in the power supply unit is a power supply device with an electrical safety function for a lighting system, characterized in that for controlling the output of the power supply unit.
The method of claim 1,
The PWM control unit,
Power supply with an electrical safety function for the lighting system, characterized in that it comprises an alarm function to warn the user when the temperature of the illumination light source, the output voltage and output current from the power supply is abnormal. Device.

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