KR20110008786A - Constant power and high power factor typed converter for led lamp - Google Patents

Abstract

PURPOSE: A constant power and high power factor type LED lamp is provided to reduce power loss by remarkably improving a power factor according to the supply current unbalance of an output DC power source by the change of an input voltage when AC power is supplied. CONSTITUTION: An EMI power supply part(1) includes a power fuse in order to prepare the inflow of an abnormal current. A rectifier part(2) includes a diode in order to rectify inputted AC power into DC power through the EMI power supply part. A boosting part(3) generates driving power which is suitable for a lighting LED module part. A current control part(4) is formed to supply a stable current to the LED module part. A high voltage rectification part(10) disconnects a great amount of current value which is provisionally generated in a circuit when an LED lamp is turned on.

Description

Converter for constant power and high power factor LED lamps {CONSTANT POWER AND HIGH POWER FACTOR TYPED CONVERTER FOR LED LAMP}

The present invention relates to a converter for a constant power and high power factor LED lamp, and more particularly, to maintain an electrostatic source and drive supply current as a driving power to drive an LED lamp composed of a plurality of lighting LEDs in series LED Controls the output current by compensating the power factor by stabilizing the output power by stabilizing the output power and supplying a constant current for the change of the input voltage. In order to improve the power factor, maintain a constant current through the current control unit, and supply it to the load LED module to improve the brightness as a lighting lamp, solve the heat problem of the LED lamp, and improve the lamp efficiency. It is to.

LED lighting device is a light source that replaces existing lighting devices such as incandescent lamps and fluorescent lamps, and has received much attention due to its high efficiency and long lifespan. Therefore, technology development is being actively conducted. LED driving power devices used in actual LED lighting lamps are modularized. It is being supplied by each LED device supplier.

The LED driving power supply may be configured in series and in parallel with the LED for illumination, and also may be composed of a combination of these to make an LED lamp and to configure a variety of light sources using the optimal driving power supply. In any case, however, LED lighting lamps can be used safely by using AC 220V, a commonly used power source, and a device that converts the supplied power and supplies suitable power, although it is not used directly from 110V AC power depending on the region. .

In general, a method used to supply driving power to an LED lamp is a switching-mode power conversion supply known as SMPS, which is a flyback-, buck-, and semi-bridge conversion method. It is used in the form of single and plural forms, and the like.

In general, LED module is divided into signal and lighting. In the past, the main power supply method is the constant voltage method which supplies a constant voltage to both ends of LED as a safe LED driving method. In addition, the power consumption is increased, and even when driving at a constant voltage, the phenomenon occurs as the heat generation temperature increases during driving, and an abnormally large current flows, which causes the LED to break down due to an interaction in which the temperature rises again. The method of limiting the current as a way to prevent this has been developed as a safer LED driving method.

Many driving circuits have been proposed for driving LED lamps. In particular, as a major standard of LED lamps, high efficiency through high power factor should be solved. Due to this problem, various integrated circuits and additional circuits are divided into parts converting commercial power into DC voltage of low voltage and processing converted power to achieve current control. There is a disadvantage that the circuit size increases. In addition, the problem of the size of the LED lamp in mass production (for example, the size of the LED fluorescent lamp replacement lamp than the conventional fluorescent lamp size or the size of the replacement LED lamp larger than the conventional incandescent lamp is not applicable to the same luminaire) The most worrisome problem is the thermal problem that is summed up when the LED module, which is the power supply and the load, is integrated, and the size of the circuit and the heat sink increases in terms of the product. In addition, due to complex circuits, there are many disadvantages such as an increase in defect factors and an increase in production cost.

In order to solve this problem, the present invention implements such that the output power of the driving power unit of the lighting LED lamp (or lighting module) as a load is a constant current source regardless of the variation of the input power, and the low power factor due to the phase difference when the power is supplied. The present invention relates to a converter circuit for power factor improvement and constant power supply. Constant power is supplied to the LED module and lamp even if the power supply fluctuates, and accordingly, the power factor of the driving power is continuously improved to maintain the high power factor, and the efficiency is improved through the problem of temperature rise (heating) and THD. And to improve safety.

The present invention for achieving the above object is, as described in Figure 3, in order to supply a stable constant voltage and constant current to the LED module portion of the LED lamp consisting of a plurality of LEDs connected in series, EMI power supply unit, and input power It provides a rectifier, a control unit (IC), a booster, a current control unit and a current control detection unit configured to rectify the high power factor and high power factor LED lighting converter.

The LED lighting converter according to the present invention greatly improves the power factor due to the thermal problem, which is a problem of the LED lamp driving power unit, and the output DC power conversion supply current imbalance due to the change of the input voltage when AC power is supplied, thereby increasing efficiency and reducing power loss. In addition, energy savings can be achieved by extending the life of LED lamps by eliminating heat generation.

Prior to examining the configuration of the power driver of the LED lamp, the concept of power used in the LED lamp is instantaneous power (see FIG. 1) as shown in Equation (1).

 p (t) = v (t) x i (t) equation (1)

In addition, to understand the relationship between power and power factor, the following concept is required, and the composition of power appears in various ways, as shown in equations (2) and (3).

-Complex Power: S [VA]

-Real power: P [W] S = P + jQ equation (2)

Reactive Power: Q [var]

식(3)-Apparent power: | S | =

Equation (3)

Root Mean Square (RMS) or Effective Value (see Figure 2)

P = V _RMS ² / R [W] = P = V _DC ² / R [W] Equation (4)

식(5) _RMS V _{RMS =}

Formula (5)

The effective value of the AC sine wave is shown in the following equations (6) and (7).

v (t) = V _m Sin wt [V] Equation (6)

식(7) _RMS V _RMS = V _m /

Formula (7)

Here, the power factor is as shown in Equation (8) below based on the above formula.

P. F = Average Power / RMS Voltage x RMS Current = P _AV / V _RMS x I _RMS Equation (8)

According to the above formula, the power factor always has a value between 0 and 1, and in order for the power factor to be close to 1, the average power value must be large and the effective value must be small. Also, when the power factor is 1, energy is most efficient from the power supply side to the load side.

If you define the relationship between the power factor and harmonics

-The effective value of sinusoidal wave is shown in equations (5) and (6), and the effective value of non-sinusoidal wave represents the given non-sinusoidal voltage using Fourier series.

식(9)v (t) = V0 + ∑ Vn cos (nwt-ψ) [V] ∴ V _RMS =

Formula (9)

This analysis shows that harmonics increase the effective value, and harmonics are independent of the magnitude of the average power, and the increase in the effective value increases the loss.

Thus, in the present invention, the current control unit and the current control detection unit is added to the PFC circuit based on the buck-boost topology in view of the above problems to maintain the high power factor of the driving power supply and solve the harmonic problem through the power factor correction circuit configuration. To provide a LED drive converter that can drive a more stable high efficiency LED lamp.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

3 is a block diagram showing the configuration of an apparatus according to the present invention, and FIGS. 4 and 5 show specific configuration examples of FIG. 3.

Externally supplied input AC power is supplied through the connector (CN1), which is a power connection, and this AC power is connected to the capacitor (C1) in parallel, and a fuse to protect the power circuit is connected to a series of connection points of C1. Coil 1 is connected to the other connection point of C1, and is connected to the input point of EMI filter (Trans 1) at each rear end, and EMI is a harmonic noise filter composed of capacitor C2 connected in parallel across the output point of EMI filter (Trans 1). It is input to the power supply 1.

The EMI filtered input power is rectified through a full-bridge rectifier 2 composed of diodes D8, 9, 10, and 11 of capacity suitable for load power in order to rectify the EMI power. The booster 3 is composed of an oscillation transformer configured in parallel by receiving the + output power of the rectifier 2 for the purpose of increasing the current effect of heat dissipation, and detecting the zero current using the induced current to control the controller 8 ( Supply to IC1).

The control unit 8 can use a commercial IC1 (for example, Thomson's model number L6561) as shown in FIG. 7, and in other inventions, such a commercially available control IC is often used. As described above, the controller of the present invention can solve reliability problems in mass production by using a commercially available IC. The controller 8 of the present invention additionally configures a zero current detection protection circuit 20 to stably detect and protect the zero current. The zero current detection protection circuit 20 includes a zener diode for supplying a constant voltage. ZD1) and R1, C10, C4 serving as filter circuits for the zero current detection power supply, and D1, R3, R4 for preventing the reverse voltage from being supplied to the zero power supply. In addition, the control unit 8 configures the stabilization circuit 30 as a circuit of the boost oscillation unit and the EMI power supply unit to stably operate the drive. The choke coil of the EMI power supply unit 1 removes AC noise, and the boost oscillation unit 7 The diodes D2, D3 and resistor R7 form a protection circuit of the FET so that the signal output from the terminal 7 of the controller is not reversed so that the current is not interrupted and the FET element is not destroyed.

Step-up oscillator 7 is composed of FET device (Q1) and diodes (D2, D3) and diodes D2 and R7 to improve the reverse current induced on the PWM signal line input to the gate of the FET device through the control unit, The diode D3 is a parasitic diode for preventing device destruction caused by the high potential difference between the drain and source terminals of the FET device. The diode D3 boosts and lowers the stable output voltage through the boost oscillator.

The high voltage rectifier 10 includes diodes D4 and D5, an NTC thermistor, and a capacitor C9. The power boosted by the boost oscillation unit 7 is rectified by a high voltage at the diode D4, and the current is increased through the diode D5 reinforced at the output of the diode D4. And smoothed through a smoothing circuit consisting of an NTC thermistor and a capacitor C9 and supplied to the current regulator 4. The high-voltage rectifier 10 is a large current value generated temporarily in the circuit when the LED lamp is turned on. This inrush current value is used to limit the inrush current by using NTC thermistor and adds various electric resistance such as resistance value and current value suitable for limiting the inrush current and reduces the initial inrush current. The temperature rises due to the heat generated by the applied current, but the NTC thermistor with negative temperature coefficient characteristic It can be lowered to protect the circuit without significant power loss.

The current controller 4 is a circuit configured to supply a stable current to the LED module, which is a load, and adjusts the output current to a stable value by receiving a + electrostatic source composed of the output current of the booster and the controlled constant voltage of the booster oscillator. Then, it is supplied to the LED module part via the output terminal protection circuit 40. In the current regulator 4, the transistors Q2 and Q3 are constituted by a reverse diring tone circuit. The power generated by the booster and the booster oscillator is supplied between the base terminal and the collector terminal of the transistor Q2, and the base terminal of Q2 is bias resistor (R21). ) Is connected to the first current repeating circuit amplified through the emit end of Q2, and the first current repeating stage is input to the base of Q3, and a series of points connected to the base end of Q2 and the bias resistor (R21) is connected to Q3. It becomes a second current repeating circuit which is input to the collector and outputs the collector terminal of Q3 having a bias resistor (R22) connected between the base terminal and the collector terminal of Q3, so that a stable second amplified current is maintained.

The current regulation detection unit 5 feeds back the output power of the current regulation unit 4 so that the comparison unit 6 detects a difference value between the input power and the input power level. The third current value is generated by using the input signal of the comparator 6, and the output value of the comparator 6 is supplied as a data input to the controller IC1, and the value of the + power and the inverter output + of the load side is generated. Is input to the comparator and supplied to the current comparator port to reflect the output level of the controller according to the value of the reference level resistance value R9 for current detection, thereby increasing the voltage current through the boost oscillator 7. The output value is a stable voltage and current is supplied to the LED module unit consisting of a plurality of lighting LEDs connected in series through the current control unit 4 that can control the voltage and current at the same time by controlling the value of the + power side. .

Between the current control unit 4 and the LED module unit includes a plurality of LED lamps and an output protection circuit 40 composed of a diode and a resistor to prevent reverse power between the current control unit.

The concept of the present invention, which is configured as described above and controls the + side power value, is a circuit stabilization method of a concept completely different from that of the existing-side current stabilization circuit, and includes a high voltage rectifying unit 10, a boost oscillation unit 7, and an LED. The protection circuit 40 of the lamp stage, the additional electrical characteristics 20 and 30 of the control unit, the current control unit 4 and the current protection detection unit 5 are characteristic features of the present invention only.

1 is a conceptual equivalent diagram of electric power

2 is an equivalent diagram for RMS

3 is a block diagram of the LED lamp converter of the present invention;

4 is a detailed circuit diagram of FIG.

5 is another detailed circuit diagram of FIG.

6 is a structure for the lamp configuration of the LED module unit

7 is a basic structural diagram of a commercial IC application of the control unit

Explanation of symbols on the main parts of the drawings

1: EMI power supply 2: rectifier

3: boosting unit 4: current adjusting unit

5: Current regulation detecting part 6: Comparison part

7: boost oscillation unit 8: control unit

20: zero current detection protection circuit 40: output stage protection circuit

Claims (6)

As a converter for LED lamps, EMI power unit consisting of a high-frequency noise filtering and a power supply fuse for input of abnormal current, A rectifier configured as a diode to rectify the AC power inputted through the EMI power unit into a DC power source; A boosting unit for generating driving power suitable for the lighting LED module unit which is a load of the DC power generated through the rectifying unit; High-voltage rectifier to prevent the large current value generated temporarily in the circuit when the LED lamp is turned on, Inverse dialling tone circuits Q2 and Q3 are configured to supply a stable current to the lighting LED module part by controlling the power control FET device using the PWM output signal of the controller to the voltage input from the booster part. Current control unit, A current regulation detecting unit configured of a coupling diode to detect a level by feeding back the output current of the load stage to the CPU of the controller so that the current supplied through the current adjusting unit is stably maintained; A comparison unit comparing the level of the current regulation detection unit with the feedback current level of the input terminal of the LED module unit and providing the control unit to the control unit; A controller which receives an electrostatic source for outputting a level signal detected by the comparator and a zero current point from the secondary induction power supply of the booster, and outputs a control level signal to a gate terminal of the FET device; Including the stabilization protection circuit of the power control element (FET) consisting of the diode (D2, D3) and the resistor (R7) to prevent the signal output from the terminal of the control unit to reverse the current is not broken and the FET element is destroyed The converter for the LED lamp, characterized in that it comprises a boost boosting unit. The method of claim 1, wherein the controller prevents the zener diode ZD1 from which the constant voltage is supplied, the elements R1, C10, C4 serving as a filter circuit of the zero current detection power, and the reverse voltage from being supplied to the zero power. Converter for LED lamps comprising a zero current detection protection circuit consisting of the elements (D1, R3, R4). The converter of claim 1, wherein the EMI power supply unit comprises a choke coil circuit. The converter of claim 1, wherein the boosting unit is configured with an oscillation transformer configured in parallel with receiving the + output power of the rectifying unit. The converter of claim 1, wherein the high-voltage rectifier comprises a rectifying diode, a current increasing diode, and a smoothing circuit comprising an NTC thermistor and a capacitor C9. According to any one of claims 1 to 5, characterized in that it further comprises an output stage protection circuit composed of a diode and a resistor for preventing reverse power between the plurality of LED lamps and the current control unit between the current control unit and the LED module unit. Converter for LED lamps.

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