CN2842983Y - Electronic ballast and hing-intensity gas dicharging lamp controller - Google Patents

Abstract

The electronic ballast and high-intensity gas discharge lamp control device of the utility model adopts different structures in different structural stages, and realizes the scheme of time-divided control. Different control techniques are designed for the different characteristics of the phase and steady-state phase: in the untriggered phase, in order to adapt the electronic ballast to the dispersion of the trigger voltage of the high-intensity gas discharge lamp, automatic scanning is adopted, and the trigger voltage is gradually increased until the high-intensity The control technology of gas discharge lamp triggering adopts real-time control technology in the starting stage; in the steady state stage, in order to make the electronic ballast adapt to the parameter dispersion of high-intensity gas discharge lamp, it adopts constant power control technology. It can drive high-intensity gas discharge lamps of various specifications, types and models, while improving efficiency, reducing electromagnetic interference, improving product reliability, reducing costs, and high output power levels.

Description

An electronic ballast and a high-intensity gas discharge lamp control device

technical field

The utility model relates to the technical field of electronic equipment and its control, in particular to an electronic ballast and a high-intensity gas discharge lamp control device in the technical field of lighting and electric energy control and transformation.

Background technique

High-intensity gas discharge lamps (including high-pressure sodium lamps and metal halide lamps, hereinafter referred to as HID lamps) are an important member of electric light source products. Compared with incandescent lamps, HID lamps have greatly improved their luminous efficiency. However, it is not so easy to maintain the stability and consistency of light color quality. HID lamps have a wide range of applications, such as store lighting, display lighting, commercial street lighting, billboard lighting, and film and television lighting. Due to their large luminous flux and excellent light color performance, they can create the best lighting effect. Excellent color rendering and light color stability can display the natural color of the illuminated object in the best state, so the application prospect of HID lamp is very broad.

In order to facilitate the understanding of the utility model, the electrical characteristics and control rules of the HID lamp are firstly introduced.

The typical electrical characteristics of HID lights are divided into three areas, which are the untriggered stage, the starting stage and the constant power stage, as shown in Figure 1: when t<t1 is the untriggered stage; when t1<t<t2 is the starting stage stage; when t>t2 is a constant power stage. The reasons for the electrical characteristics of each working area and the corresponding control laws are explained below.

1. Untriggered stage

During the untriggered phase, no charge carriers exist between the poles of the bulb because the gas atoms inside the bulb are not ionized. Therefore, in the untriggered stage, the HID lamp is equivalent to an open circuit, the terminal voltage of the lamp is the output voltage of the ballast, and the current and power of the lamp are both zero. When the output voltage of the ballast reaches the trigger voltage Uk of the lamp, the gas atoms in the lamp get enough energy to be ionized and generate many electrons—ion pairs. At this time, the electrons become free electrons, equivalent to a free negative charge , the ion can be equivalent to a positive charge. Therefore, both electrons and ions can participate in conduction, and this electron-ion pair is called a carrier.

Providing the proper trigger voltage is a concern for electronic ballast designers. At the moment of triggering the lamp, if the voltage provided by the ballast is much greater than the trigger voltage Uk of the lamp, the electrodes of the lamp will be damaged at the trigger moment and the service life of the lamp will be shortened; however, if the voltage provided by the ballast is less than Uk, the The gas cannot be ionized, an arc cannot be formed, and the lamp cannot start working. In conclusion, providing an appropriate trigger voltage is an important issue. Ideally, the ballast provides a voltage that is just equal to or slightly greater than the lamp's trigger voltage. But the difficulty encountered by designers is that for HID lamps with the same output power, the trigger voltage is not a fixed electrical parameter. For HID lamps with the same output power and the same type, the trigger voltages of bulbs provided by different manufacturers are quite different; the trigger voltages of the same type of bulbs provided by the same manufacturer are also different; even the same bulb, Its trigger voltage is also affected by factors such as ambient temperature, humidity, and surrounding electric field distribution. Therefore, the voltage provided by the ballast must be properly adjusted anytime and anywhere, that is, the ballast must have the ability to provide a trigger voltage adaptively.

The moment the HID lamp is triggered, its electrical characteristics have the following two notable features:

Feature 1: The terminal voltage of the lamp instantly changes from the trigger voltage (very high voltage) to 20% to 30% of the rated working voltage (low voltage).

Feature 2: The current of the lamp jumps instantly from zero to 140% to 150% of the rated output current.

The combination of the above two features can be used to determine whether the HID lamp is triggered.

2. Start-up phase

When the HID lamp is triggered by the high voltage provided by the ballast, the gas atoms located between the two electrodes are ionized to form free electrons and ion pairs. Since these free electrons have obtained high enough energy, when these free electrons collide with other When the unionized gas atoms are not ionized, the collided atoms are ionized to form new free electrons—ion pairs, and the new free electrons can collide with other atoms to generate more free electrons and ion pairs, thus producing an avalanche effect. Free electrons - ion pairs (collectively referred to as carriers) suddenly increase dramatically. Since all carriers can participate in conduction at this time, a conductive channel with a large cross-sectional area and approximately cylindrical shape centered on the two electrodes is formed, and the lamp presents low resistance characteristics at this time. At this time, the free electron-ion pair is in a saturated state, which can provide enough carriers for the external power supply.

After the lamp is triggered, there are a large number of free electrons and ion pairs in the cylindrical conductive channel centered on the two poles, and these electron-ion pairs will perform diffusion and drift motions. Under the action of the electric field applied to the two electrodes, some electrons-ion pairs will make directional drift along the direction of the two electrodes, forming the discharge current of the lamp. This part of electrons-ion pairs participate in conduction, so they are called carriers. And because a large concentration gradient is formed from the axis of the cylindrical conductive channel to the tube wall of the bulb, another part of electrons—ion pairs diffuse from the axis to the tube wall, and electrons and ions recombine to form in the process of diffusion. atom. (Electrons for diffusion movement——ion pairs, although charged, they cannot conduct current, so they are not carriers). These atoms are concentrated on the tube wall, forming a large atomic concentration gradient difference with the central axis of the conductive channel. The atoms diffuse from the tube wall to the central axis and reach the cylindrical conductive channel. Because the temperature of the central column is relatively high High, the electrons get enough energy to be ionized again. The higher the temperature of the conductive channel, the faster the rate at which atoms are ionized.

During start-up, the rate of ionization is much slower than the rate of electron-ion recombination. There are two reasons for this. The first reason is that in the early stage of lamp starting, the tube wall of the bulb, the surrounding environment, the gas in the bulb, the cylindrical conductive channel, etc. have a relatively low temperature, so the ionization speed is lower; the second reason is that the larger drift movement Makes more electrons-ion pairs participate in conduction, and reduces the number of electrons-ion pairs participating in the diffusion movement. During the starting process, the role of ballast is to limit and gradually reduce the number of electrons participating in the drift - the number of ion pairs, to gradually increase the internal and ambient temperature, increase the number of electrons participating in the diffusion movement - ion pairs and enhance the recombination rate , so that the ionization rate is much lower than the recombination rate. In this working condition, the cross-sectional area of the conductive channel and the concentration of internal carriers are gradually decreasing, the terminal voltage of the lamp is gradually increasing, the current is gradually decreasing, and its equivalent resistance is also gradually increasing, and the lamp The power loss should gradually increase.

From the user's point of view, at the moment when the HID lamp is triggered, the temperature of the tube wall of the lamp is equal to the ambient temperature of the outside world. Although the temperature of the conductive channel is not very high, the temperature of the tube wall is still much lower than that of the conductive channel. temperature. During the starting process of the lamp, due to the thermal radiation of the conductive channel, the temperature of the tube wall should rise evenly. Because the center of the arc will not be exactly at the geometric center of the lamp tube, the temperature distribution on the lamp tube wall will be uneven. If the starting current is too large, the temperature of some parts of the tube wall will rise rapidly, and it will be too late to conduct to the surroundings, resulting in Partial damage to the tube wall. The correct method is that the current of the lamp should not be too large, and should be gradually reduced, and the voltage and lamp power consumption should be gradually increased, and the growth rate of the output power should be smaller than the heat conduction rate of the tube wall. Conversely, if the starting current is too small, the temperature in the cylindrical conductive channel is too low to ionize the atoms, so as time increases, the electron-ion pairs caused by the trigger are exhausted due to recombination, thereby causing arc discharge Unable to maintain, the phenomenon of arc extinguishing occurs. Therefore, it is necessary to study a reasonable starting rule to achieve the purpose of maintaining the arc discharge and uniformly increasing the temperature of the bulb tube wall. The start-up control law proposed in this patent is to limit the maximum current at the start-up moment of the HID lamp, gradually reduce the current and increase the power dissipation of the lamp with an exponential or approximate exponential law. The specific method is to limit the current of the lamp to the rated value (140%~150%) at the moment the lamp is triggered, and at the same time control the dissipation of the lamp to the rated power of (20%~30%). reach a steady state.

During start-up, the power dissipated by the lamp is increasing and the temperature in the conductive channel area will be increasing. As the temperature increases, the rate of ionization increases greatly, while the rate of recombination decreases continuously. It should be noted that the increase in the ionization rate also facilitates the diffusion movement, reduces the electron-ion pairs participating in the drift movement, and gradually reduces the cross-sectional area of the conductive channel. When steady state is reached, the rate of ionization is approximately equal to the rate of recombination. However, since the temperature in the central area of the lamp has not yet reached a steady state, as the temperature of the lamp continues to rise slowly, the rate of ionization is slightly greater than the rate of recombination.

3. The constant power stage is also called the steady state region

When the electrical characteristics of the lamp reach a steady state, because the temperature in the central area of the lamp will increase slowly, the ionization speed may increase; another reason is that the terminal voltage of the lamp is high enough and the temperature in the central area Higher, which also helps to increase the ionization velocity. The common result of the above two reasons is that when the lamp reaches electrical stability, the rate of ionization is still greater than the rate of recombination, so the gas in the lamp tube still has enough electron-ion pairs. The number of carriers participating in conduction is controlled by an external ballast. The larger the current provided by the external ballast, the larger the number of carriers involved in conduction, the smaller the equivalent resistance, and the lower the terminal voltage of the lamp. as shown in picture 2. Therefore, the function of the ballast is that when the lamp reaches a steady state, mainly by controlling the current of the lamp, the diffusion movement and drift movement of the gas in the lamp reach a steady state, and the ionization rate is just equal to the recombination rate, reaching the terminal voltage of the lamp. Basically remain unchanged, to achieve constant power control. At point A, there is a composite relationship between the power supply voltage Vs, the discharge voltage Vd and the discharge current i: Vs=Vd+iR, where R is the equivalent resistance of the electronic ballast.

However, constant power control cannot be achieved by only using the method of stabilizing the current, because the terminal voltage of the lamp is not a fixed constant, even if the current of the lamp is the same. The lamp terminal voltage is not constant for the following reasons:

1. The length of the discharge arc is an important factor in determining the lamp terminal voltage. It can be imagined that the discharge arc is like a rubber ribbon tied to the two electrical terminals. The length of the ribbon is affected by many factors such as the position of the lamp, the gravitational force of the geomagnetic field, the distribution of the gas temperature field in the lamp, and the direction of motion. Therefore, even if a constant current power supply is used, the terminal voltage of the lamp will change accordingly due to different regions of use and different placement positions of the lamp.

2. For the same type of HID lamp produced by different manufacturers, the distance between the two electrodes will be quite different, that is, the distance between the two electrodes of the same type of lamp produced by the same manufacturer also has a certain dispersion.

3. As the service time of the lamp increases, the distance between the two electrodes increases continuously, so the tube pressure also increases.

Therefore, the difference between HID lamps and ordinary incandescent lamps is that HID lamps need to use electronic ballasts in order to work properly during application. At present, electronic ballasts generally have a typical electronic ballast topology and two modulation techniques.

A typical electronic ballast topology is an electronic ballast topology that outputs low-frequency square wave voltage and current, including an active power factor correction circuit, step-down BUCK converter and inverter. The active power factor correction circuit is used to improve the power factor of the input terminal, reduce the high-order harmonics of the input current, and provide a constant voltage of about 400V for the BUCK converter; the BUCK converter acts as a current and power regulator to make its output current , The voltage and power match the electrical characteristics of the lamp; the inverter converts the output of the BUCK converter into the AC signal required by the HID lamp, so this electronic ballast has the following disadvantages: many links, resulting in low efficiency, electromagnetic Great interference. (References are: US Patent, US, 6,278,245B1)

One of the modulation techniques is an intermediate frequency modulation technique. Electronic ballasts work in a frequency range greater than 20kHz and less than 100kHz, using frequency modulation, angle modulation and amplitude modulation. The purpose of using this intermediate frequency modulation technology for electronic ballasts is to distribute the spectrum of the output power in a certain frequency band, so as to avoid the "acoustic resonance" phenomenon of HID lamps due to the excessive concentration of the power spectrum. The main disadvantages of the electronic ballast using this intermediate frequency modulation technology include: the control circuit is complicated, and it cannot be generally applied to HID lamps of various specifications, types and models. (References are: US Patent, US, 6,184,633B1)

The second modulation technique is a high-frequency modulation technique, and the electronic ballast works in a certain frequency band greater than 100kHz. Generally, when the operating frequency of the HID lamp is greater than 100kHz, there will be no "acoustic resonance" phenomenon. The main disadvantages of electronic ballasts using this high-frequency modulation technology are: low efficiency, large electromagnetic interference, and it is difficult to meet the requirements of relevant international and national standards. (References are: US Patent, US, 6,181,076B1)

Currently commonly used control technology, when the output power of the electronic ballast is small, this control technology can basically meet the requirements of the high-intensity discharge lamp and make the system work stably, but the experimental results show that when the output power of the electronic ballast is large , this control technology cannot meet the requirements of high-intensity discharge lamps and the system is difficult to work stably.

This requires a control method for electronic ballasts and HID lamp control devices, which can drive HID lamps of various specifications, types and models, while improving efficiency, reducing electromagnetic interference, improving product reliability, reducing costs, and output High power rating.

Utility model content

In view of the problems existing in the above-mentioned prior art, the purpose of this utility model is to provide an electronic ballast and a high-intensity gas discharge lamp control device, which can drive high-intensity gas discharge lamps of various specifications, types and models, and at the same time improve Efficiency, reduce electromagnetic interference, improve product reliability, reduce cost, high output power level.

The purpose of this utility model is achieved by the following technical solutions:

An electronic ballast comprising:

Rectifier circuit: the input terminal is connected to an AC power supply, and the input terminal is connected to a power factor correction circuit after rectifying the input AC power supply;

Power factor correction circuit: the input terminal is connected to the rectifier circuit, and the power factor correction is performed on the rectified power supply, and the output terminal is connected to the series-parallel resonant inverter circuit;

Series-parallel resonant inverter circuit: the input terminal is connected to a power factor correction circuit, and the power factor corrected power supply is converted into a high-frequency AC power supply suitable for the load through high-frequency resonance, and the output terminal is connected to the load.

The series-parallel resonant inverter circuit includes:

Half-bridge conversion circuit: the input end is connected to the output end of the power factor correction circuit, including the first power switch tube, the second power switch tube, the first power diode, and the second power diode. The two power switch tubes are connected in series, and the first power switch tube The source of the switch tube and the drain of the second power switch tube are connected to the output of the power factor correction circuit. The poles are connected, and the gates of the two power switch tubes are connected to the drive circuit; the output end of the half-bridge conversion circuit is connected to the series-parallel resonant tank circuit;

Series-parallel resonant tank circuit: the input terminal is connected to the half-bridge conversion circuit, and the output terminal is connected to the load. It is composed of the first capacitor, inductor and second capacitor connected in series. The series-parallel resonant tank circuit is connected in parallel to the drain of the second power switch tube. Between the source and the source, one end of the first capacitor is connected to the drain of the second power switch tube, one end of the second capacitor is connected to the source of the second power switch tube, and the load is connected in parallel with the second capacitor.

The first power switch tube and the second power switch tube are IRFP450 type power field effect transistor MOSFET; or

The first power diode and the second power diode are MUR460; or

The inductance is 100μH~200μH; or

The first capacitor and the second capacitor are 1nF~20nF.

A high-intensity gas discharge lamp control device based on the above-mentioned electronic ballast, comprising an electronic ballast and:

Drive circuit: connected with the electronic ballast and the control circuit, and executes the instructions of the control circuit to drive the electronic ballast;

Control circuit: connected with the drive circuit and signal acquisition circuit, generates control signals according to the electronic ballasts and high-intensity gas discharge lamps collected by the signal acquisition circuit, and sends control instructions to the drive circuit;

Signal acquisition circuit: connected with the electronic ballast, high-intensity gas discharge lamp and control circuit, and collects the working conditions of the electronic ballast and high-intensity gas discharge lamp.

The drive circuit includes:

Voltage-controlled oscillator: the input terminal is connected to the control circuit, the output terminal is connected to the T flip-flop, the input voltage signal, and the output proportional frequency signal;

T flip-flop: the input terminal is connected to the voltage-controlled oscillator, the output terminal is connected to the driver, and the signal of the voltage-controlled oscillator is divided by two to form two control signals with opposite phases;

Driver: The input terminal is connected to the driver, and the output terminal is connected to the electronic ballast, including the first driver and the second driver, which control the two power switch tubes of the half-bridge conversion circuit in the electronic ballast according to the control signal output by the T flip-flop .

The control circuit includes:

Control switch: the input end is connected to the selected state controller and the state controller group, and the output end is connected to the voltage-controlled oscillator of the driving circuit; according to the control signal of the selected state controller, the signal of the corresponding state controller in the state controller group is output to voltage controlled oscillator;

Selection state controller: the input terminal is connected to the signal acquisition circuit, and according to the working conditions of the electronic ballast and the high-intensity gas discharge lamp collected by the signal acquisition circuit, corresponding control signals for selecting different state controllers are generated and output to the control switch and state controller group;

State controller group: including one or more state controllers, the input terminal can be connected to the signal acquisition circuit and/or select the state controller, according to the working conditions and selection of electronic ballasts and high-intensity gas discharge lamps collected by the acquisition circuit The control signal of the state controller uses the corresponding output signal of the state controller as an output signal; the output signal is output to the control switch through the output terminal.

The state controller group includes:

Trigger controller: generate a control signal in the untriggered stage, and the output end is connected to an input end of the control switch;

Start controller: generate the control signal in the start phase, the input signal includes the electronic ballast and the working condition signal of the high-intensity gas discharge lamp collected by the acquisition circuit and the control signal of the selection state controller, and the output terminal is connected to an input terminal of the control switch ;

Constant power controller: It generates the control signal in the constant power stage. The input signal includes the electronic ballast and high-intensity gas discharge lamp working condition signal collected by the acquisition circuit and the control signal of the selected state controller. The output terminal is connected to one of the control switches. input.

Described starting controller comprises:

Starter amplifier: it can be an error amplifier, one input terminal is connected to the signal acquisition circuit, the other input terminal is connected to the exponential voltage generator, and the output terminal is connected to the control switch;

Exponential voltage generator: the input terminal is connected to the selection state controller, and the output terminal is connected to the amplifier.

Described constant power controller comprises:

Constant power amplifier: one input divider, the other input is grounded through a reference voltage source, and the output is connected to a control switch;

Multiplier: the input terminal is connected to the signal acquisition circuit, and the output terminal is connected to the divider;

Divider: The input terminal is connected to the multiplier, and the output terminal is connected to the amplifier.

The signal acquisition circuit includes:

Voltage processing circuit: the input terminal is connected with electronic ballast and/or high-intensity gas discharge lamp, the high-frequency AC voltage signal is collected and processed into a DC voltage signal, and the output terminal is connected with the selection state controller and the state controller group;

Current processing circuit: the input terminal is connected with electronic ballast and/or high-intensity gas discharge lamp, the high-frequency AC current signal is collected and processed into a DC voltage signal, and the output terminal is connected with the selection state controller and the state controller group.

It can be seen from the above-mentioned technical solution provided by the utility model that the electronic ballast and the high-intensity gas discharge lamp control device of the utility model adopt different structures at different stages of the structure, and realize the scheme of time-sharing control , different control technologies are designed for the different characteristics of high-intensity discharge lamps in the untriggered phase, starting phase and steady-state phase: In the untriggered phase, in order to adapt the electronic ballast to the dispersion of the trigger voltage of the high-intensity gas discharge lamp, The control technology of automatic scanning, gradually increasing the trigger voltage until the high-intensity gas discharge lamp is triggered, adopts real-time control technology in the starting stage; in the steady state stage, in order to make the electronic ballast adapt to the parameter dispersion of the high-intensity gas discharge lamp , using constant power control technology. It can drive high-intensity gas discharge lamps of various specifications, types and models, while improving efficiency, reducing electromagnetic interference, improving product reliability, reducing costs, and high output power levels.

Description of drawings

Figure 1 is an electrical characteristic diagram of a high-intensity gas discharge lamp;

Figure 2 is a load characteristic diagram of a high-intensity gas discharge lamp;

Fig. 3 is the circuit diagram of the electronic ballast described in the utility model;

Fig. 4 is the circuit principle block diagram of the electronic ballast described in the utility model;

Fig. 5 is the waveform diagram of each key point in the circuit of the electronic ballast described in the utility model;

Fig. 6 is a schematic block diagram 1 of the electronic ballast-based high-intensity discharge lamp control device described in the present invention;

Fig. 7 is a schematic block diagram 2 of the electronic ballast-based high-intensity discharge lamp control device according to the present invention;

Fig. 8 is a graph showing the relationship between output voltage and time of the trigger controller of the electronic ballast-based high-intensity discharge lamp control device described in the present invention;

Fig. 9 is a structural schematic diagram of the starting controller of the electronic ballast-based high-intensity discharge lamp control device described in the present invention;

Fig. 10 is a structural schematic diagram of the constant power controller of the electronic ballast-based high-intensity discharge lamp control device described in the present invention;

Fig. 11 is a control sequence diagram of the control method of the electronic ballast-based high-intensity discharge lamp control device described in the present invention;

Fig. 12 shows the terminal voltage and working of the high-intensity gas discharge lamp before the high-intensity gas discharge lamp is triggered during the control process of the control method of the electronic ballast-based high-intensity gas discharge lamp control device described in the present invention frequency diagram;

Fig. 13 is the terminal voltage and working of the high-intensity gas discharge lamp during the starting process of the high-intensity gas discharge lamp during the control process of the control method of the high-intensity gas discharge lamp control device based on the electronic ballast described in the utility model Frequency diagram.

Detailed ways

The specific implementation of the method for controlling an electronic ballast and a high-intensity gas discharge lamp control device described in the utility model is as follows:

The specific implementation of its electronic ballast——Example 1

As shown in FIG. 3 and FIG. 4 , an electronic ballast includes: a rectifier circuit, a power factor correction circuit, a power factor correction circuit and a series-parallel resonant inverter circuit. The series-parallel resonant inverter circuit includes a half-bridge conversion circuit and a series-parallel resonant tank circuit. The rectifier circuit is sequentially connected to the power factor correction circuit, the half-bridge conversion circuit and the series-parallel resonant tank circuit. in:

The rectifier circuit is composed of a bridge rectifier, the input terminal is connected to the AC power supply, the input terminal is rectified and then the output terminal is connected to the power factor correction circuit; of course, a filter circuit can also be connected between the bridge rectifier and the AC power supply. AC power is filtered before it is rectified.

Power factor correction circuit: It is composed of a power switch tube S and a capacitor C connected in parallel. The source and drain of the power switch tube S are connected to the output terminal of the rectifier circuit at the input terminal, and there is a series connection between the source terminal and the output terminal of the rectifier circuit. The first inductance L1; the node where the source is connected in parallel with the capacitor C is also connected in series with a capacitor C. This circuit performs power factor correction on the rectified power supply, and the output terminal is connected to a series-parallel resonant inverter circuit.

Series-parallel resonant inverter circuit: the input terminal is connected to a power factor correction circuit, and the power factor corrected power supply is converted into a power supply suitable for the load through high-frequency resonance, and the output terminal is connected to the load.

The series-parallel resonant inverter circuit includes a half-bridge conversion circuit and a series-parallel resonant tank circuit. in:

Half-bridge conversion circuit: the input end is connected to the output end of the power factor correction circuit, including the first power switch S ₁ , the second power switch S ₂ , the first power diode D ₁ , the second power diode D ₂ , two The power switch tubes are connected in series, the source of the first power switch tube _S1 and the drain of the second power switch tube _S2 are connected to the output of the power factor correction circuit, the two power diodes are respectively connected in parallel with the two power switch tubes, and the two power The cathodes of the diodes are respectively connected to the drains of the two power switch tubes, and the gates of the two power switch tubes are connected to the drive circuit; the output end of the half-bridge conversion circuit is connected to the series-parallel resonant tank circuit;

Series-parallel resonant tank circuit: the input terminal is connected to the half-bridge conversion circuit, and the output terminal is connected to the load. It is composed of the first capacitor C ₁ , the inductor L and the second capacitor C ₂ in series. The series-parallel resonant tank circuit is connected in parallel with the second power Between the drain and source of the switch tube _S2 , one end of the first capacitor _C1 is connected to the drain of the second power switch tube _S2 , and one end of the second capacitor is connected to the source of _S2 of the second power switch tube The poles are connected, and the load is connected in parallel with the second capacitor _C2 .

The above-mentioned first power switch tube _S1 and second power switch tube _S2 are IRFP450 type power field effect transistor MOSFET;

The above-mentioned first power diode D ₁ and second power diode D ₂ are MUR460;

The aforementioned inductance L and the first inductance _L1 are 100 μH to 200 μH;

The first capacitor _C1 and the second capacitor _C2 are 1nF~20nF.

Fig. 5 is the waveform of each key point in the circuit shown in Fig. 3: _Vg1 and _Vg2 are respectively the drive signal of power switch _S1 and the second power switch _S2 in Fig. 3 among the figure (a); ) in I _D1 and I _D2 are the current waveforms of the power diode _{D1 and} the second power diode _D2 in Fig. 3 respectively; I _S1 and I _S2 in Fig. The current waveform of the power switch tube _S2 ; Figure (d) is the voltage waveform of the power switch tube _S1 ; Figure (e) is the voltage waveform of the second power switch tube _S2 .

Its specific implementation of the high-intensity gas discharge lamp control device based on the above-mentioned electronic ballast——Example 2

As shown in Figure 6 and Figure 7,

A high-intensity gas discharge lamp control device based on the above-mentioned electronic ballast, including an electronic ballast, a drive circuit, a control circuit and a signal acquisition circuit, wherein:

The driving circuit is connected with the electronic ballast and the control circuit, and executes the instructions of the control circuit to drive the electronic ballast; the driving circuit includes a voltage-controlled oscillator VFO, a trigger and a driver, wherein:

Voltage-controlled oscillator VFO: the input terminal is connected to the control circuit, the output terminal is connected to the trigger, the input voltage signal, and the output proportional frequency signal.

Trigger: the input terminal is connected to the voltage-controlled oscillator VFO, the output terminal is connected to the driver, and the signal of the voltage-controlled oscillator VFO is processed into a control signal for control; the trigger uses a T flip-flop, and the output signal of the voltage-controlled oscillator VFO is Divide by two and form two Q and Q sums that are opposite to each other Q signal.

Driver: the input terminal is connected to the driver, and the output terminal is connected to the electronic ballast, including the first driver and the second driver, which control the two power switch tubes of the half-bridge conversion circuit in the electronic ballast according to the signal output by the trigger.

The control circuit is connected with the drive circuit and the signal acquisition circuit, generates control signals according to the working conditions of the electronic ballast and the high-intensity gas discharge lamp collected by the signal acquisition circuit, and sends control instructions to the drive circuit; the control circuit includes control switches, selection State controller and state controller group, where:

Control switch: the input end is connected to the selected state controller and the state controller group, and the output end is connected to the voltage-controlled oscillator VFO of the driving circuit; according to the control signal of the selected state controller, the signal of the corresponding state controller in the state controller group is output To the Voltage Controlled Oscillator VFO.

Selection state controller: the input terminal is connected to the signal acquisition circuit, and according to the working conditions of the electronic ballast and the high-intensity gas discharge lamp collected by the signal acquisition circuit, corresponding control signals for selecting different state controllers are generated and output to the control switch and State controller group. The selection state controller has two input signals U ₀₁ and U ₀₂ , and the two output signals are P ₁ and P ₂ respectively. At the moment of starting up, the switch S is in position ①. When the selection state controller detects a negative transition at the lamp terminal and a negative transition at the equal current, P ₂ sends out a signal to make the index generator in the starting controller B ₂ start to work, and at the same time P ₁ sends out a signal to make the switch S is in the ② position. When the selected state controller detects that the terminal voltage and current of the lamp have reached its rated value, P ₁ sends out a signal to make the switch in position ③.

State controller group: including one or more state controllers, the input terminal can be connected to the signal acquisition circuit and/or select the state controller, according to the working conditions and selection of electronic ballasts and high-intensity gas discharge lamps collected by the acquisition circuit The control signal of the state controller takes the output signal of the corresponding state controller as the output signal; this output signal is output to the control switch through the output terminal; the described state controller group includes trigger controller B1, start controller B2 and constant power Controller B3, where:

Trigger controller B1: generates a control signal for the non-triggered stage, and the output end is connected to an input end of the control switch. The trigger controller U _B1 is a sweep voltage generator. The relationship between its output voltage and time is shown in Figure 8. At the moment of power-on, the trigger controller starts to work, and its output voltage drops linearly, with its maximum value U _H and minimum value U _L . When U _B1 =U _H , the voltage-controlled oscillator VFO outputs the highest frequency, and when U _B1 = _UL , the corresponding voltage-controlled oscillator VFO outputs the lowest frequency. Automatic scanning gradually increases the output voltage until the trigger voltage provided by the electronic ballast is just equal to or slightly greater than the trigger voltage required by the lamp at this time and here, and the high-intensity gas discharge lamp starts to trigger.

Start controller B2: Generate control signals in the start phase, the input signals include electronic ballasts and high-intensity gas discharge lamp working condition signals collected by the acquisition circuit and control signals of the selection state controller, and the output terminal is connected to an input of the control switch end. As shown in Figure 9, the starting controller B2 includes a starting amplifier and an exponential voltage generator wherein:

Starter amplifier: it can be an error amplifier, one input terminal is connected to a signal acquisition circuit, the other input terminal is connected to an exponential voltage generator, and the output terminal is connected to a control switch.

Exponential voltage generator: the input terminal is connected to the selection state controller, and the output terminal is connected to the amplifier.

In Figure 9 A1 is the error amplifier. The control signal _P2 controls whether the exponential voltage generator works. When _P2 is high, the exponential voltage generator decays exponentially and provides a parameter voltage for the error amplifier A1.

Constant power controller B3: Generates control signals in the constant power stage. The input signals include electronic ballasts and high-intensity gas discharge lamp working condition signals collected by the acquisition circuit and control signals of the selected state controller. The output terminal is connected to the control switch. an input terminal. The constant power controller B3 shown in Figure 10 includes a constant power amplifier, a multiplier and a divider, wherein:

Constant power amplifier: one input end divider, the other input end is grounded through a grounding capacitor, and the output end is connected to a control switch;

Multiplier: the input terminal is connected to the signal acquisition circuit, and the output terminal is connected to the divider;

Divider: The input terminal is connected to the multiplier, and the output terminal is connected to the amplifier. The function of the divider is to divide a fixed voltage by the product of U ₀₁ and U ₀₂ , so that the output signal U ₀₃ is proportional to the output power of U ₀₁ and U ₀₂ .

Signal acquisition circuit: connected with the electronic ballast, high-intensity gas discharge lamp and control circuit, and collects the working conditions of the electronic ballast and high-intensity gas discharge lamp. The signal acquisition circuit includes a voltage processing circuit and a current processing circuit, wherein:

Voltage processing circuit: usually includes a voltage sensor, the input terminal is connected to an electronic ballast and/or a high-intensity gas discharge lamp, the high-frequency AC voltage signal is collected and processed into a DC voltage signal, and the output terminal is connected to a selection state controller and a state controller group ; Including lamp terminal voltage sampling network, rectifier, filter, its input signal is lamp terminal voltage U _lamp - high-frequency AC signal, its output voltage U ₀₁ - approximate DC voltage, U ₀₁ is proportional to the effective value of U _lamp .

Current processing circuit: usually includes a current sensor, the input terminal is connected to an electronic ballast and/or a high-intensity gas discharge lamp, the high-frequency AC current signal is collected and processed into a DC voltage signal, and the output terminal is connected to a selection state controller and a state controller group . It includes a current sampling network, a rectifier and a filter _. Its input signal is the lamp current I _lamp - a high-frequency signal, and its output voltage U ₀₂ is proportional to the effective value of I _lamp .

In order to facilitate the in-depth understanding of the present utility model, the specific implementation of the control method of the high-intensity gas discharge lamp control device based on the above-mentioned electronic ballast is introduced below—Example 3

A control method based on the high-intensity discharge lamp control device based on the above-mentioned electronic ballast, comprising:

The first step, the control circuit drives the electronic ballast through the drive circuit according to the working status of the electronic ballast and the high-intensity gas discharge lamp collected by the signal acquisition circuit; it is specifically divided into the following steps:

1. The signal acquisition circuit collects the information of the working status of the electronic ballast and the high-intensity gas discharge lamp, and outputs the control signal to the selection state controller and the state controller group; the specific steps can be divided into the following steps:

(1), the voltage processing circuit of the signal acquisition circuit collects the high-frequency AC voltage signal _UR of the high-intensity gas discharge lamp and processes it to form an approximate DC voltage signal U ₀₁ proportional to the effective value of _UR ;

at the same time,

(2), the current processing circuit of the signal acquisition circuit collects the high-frequency alternating current signal I _R of the high-intensity gas discharge lamp after processing and becomes an approximate DC voltage signal U ₀₂ proportional to the effective value of I _R ;

And U ₀₁ and U ₀₂ are used as the input signals for selecting the state controller and the state controller group.

2. Select the state controller and the state controller group to connect the corresponding state controller output terminal and the drive circuit through the control switch according to the control signal described in step A1; output the control signal of the state controller output terminal to the drive circuit; Specifically, it can be divided into the following steps:

(1), the selection state controller inputs two signals U ₀₁ and U ₀₂ , and outputs two control signals P ₁ and P ₂ ;

(2), when the high-intensity gas discharge lamp just starts to work when the power is turned on, there are no control signals _P1 and _P2 ; the control switch is connected to trigger the controller and the drive circuit;

or,

When the high-intensity gas discharge lamp is triggered, the selected state controller outputs control signals P ₁ and P ₂ , P ₁ makes the control switch connect the starting controller and the driving circuit; P ₂ makes the exponential voltage generator start to work, and the starting amplifier outputs Control signal to drive circuit;

or,

When the high-intensity gas discharge lamp is started, the working state of the high-intensity gas discharge lamp reaches a steady state, and the state controller is selected to output the control signal P ₁ to connect the constant power controller and the driving circuit; the constant power amplifier of the constant power controller Output the control signal to the drive circuit.

3. The driving circuit drives the electronic ballast to work and controls the working process of the high-intensity gas discharge lamp.

In the second step, the electronic ballast outputs corresponding parameter output electrical signals at different stages of the high-intensity gas discharge lamp according to the driving signal to drive the high-intensity gas discharge lamp to work. Specifically divided into the following steps:

1. In the untriggered stage, the trigger drive signal obtained from the trigger controller controls the electronic ballast to output a linearly increased output voltage. When the trigger voltage is reached, the high-intensity gas discharge lamp starts to trigger;

or,

2. In the starting stage, the starting driving signal obtained from the starting controller, the starting driving signal controls the real-time control of the electronic ballast to output the output voltage that adapts to the starting characteristics according to the change of the working current of the high-intensity gas discharge lamp, and the high-intensity gas discharge lamp The discharge lamp starts normally;

or,

3. In the stable working stage, the constant power drive signal is obtained from the constant power controller. This constant power drive signal is controlled by the closed-loop control of the working current and working voltage of the high-intensity gas discharge lamp, and the output of the electronic ballast is constant power. A set of parameters, the high-intensity discharge lamp operates at a constant power in a stable phase.

The specific process of the control process is as follows:

The timing diagram of the control circuit work is shown in Figure 11. Time zone ① corresponds to automatic scanning and gradually increases the output voltage until the output voltage is equal to the trigger voltage of the lamp. Time zone ① ends, time zone ② starts, and so on.

1. The control law of the untriggered stage:

Figure 12 shows the relationship between the electronic ballast output voltage U _lamp and the operating frequency in the non-triggered stage. In Fig. 11, at the moment of power-on, at the time t=0, the switch S is connected to the trigger controller B1, and the output voltage U _B1 of the trigger controller B1 drops linearly from the maximum value U _H at this moment, and the voltage-controlled oscillator VFO The input frequency decreases linearly, that is, the operating frequency of the circuit gradually decreases. At this time, the input voltage of the main circuit gradually increases automatically. When the terminal U _lamp of the lamp is equal to the trigger voltage U _k , the gas in the lamp is broken down and arc discharge begins.

2. The control law in the starting stage:

Figure 13 shows the relationship between the output voltage of the electronic ballast and the operating frequency during the starting phase. At the moment of triggering, the equivalent resistance of the lamp is very small, so it corresponds to a lower output voltage. When the lamp reaches a steady state, its equivalent resistance is larger, corresponding to a larger output voltage. When the lamp is triggered, the selection state controller sends two signals P ₁ and P ₂ . P ₁ puts S at terminal ②, and P ₂ makes the index generator in the starting controller B2 start to work. At this time, the current feedback starts to work, and the operating frequency of the control circuit is f ₂ . As the current of the lamp decreases, the terminal voltage of the lamp increases, and the operating frequency transitions from _f2 to _f3 . If the loop gain of this current-controlled closed-loop loop is infinite, the output current will vary exponentially. In Fig. 11, I _ON and U _ON are the rated current and voltage of the lamp.

3. Constant power control:

When the lamp reaches a steady state, select the output signal _P1 of the state controller to make the switch throw at the position of ③. At this time, both the output voltage and the output current participate in the feedback, forming a closed-loop feedback system. The output power is completely controlled by the internal reference voltage of the constant power controller B3.

The utility model designs different control technologies for the different characteristics of the high-intensity gas discharge lamp in the untriggered stage, the starting stage and the steady state stage: in the untriggered stage, in order to make the electronic ballast adapt to the dispersion of the trigger voltage of the high-intensity gas discharge lamp It adopts the control technology of automatic scanning, gradually increasing the trigger voltage until the high-intensity discharge lamp is triggered, and adopts real-time control technology in the starting stage; in the steady state stage, in order to make the electronic ballast adapt to the parameters of the high-intensity discharge lamp Dispersion, using constant power control technology.

The utility model compares with prior art as shown in table 1:

Table 1 technical indicators existing technology The utility model efficiency 85% 95% cost high Low (about 1/3 less than the existing technology) trigger Additional triggers are required No additional trigger required electromagnetic interference big Small

Since the electronic ballast described in the utility model contains a series-parallel resonant tank with a high Q value, when the system is in a steady state, the output voltage of the series-parallel resonant tank is an approximate sine wave, and the sine wave is not easy to induce HID The acoustic resonance phenomenon of the lamp; in the non-triggered stage, the HID lamp is equivalent to a high resistance resistor, which is used as the load of the series-parallel resonant tank circuit. At this time, the series-parallel resonant tank circuit can provide a high voltage of several thousand volts as a trigger signal, so no external trigger is required.

The above is only a preferred embodiment of the utility model, but the scope of protection of the utility model is not limited thereto, and any person familiar with the technical field can easily think of All changes or replacements should fall within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (10)

1. An electronic ballast, characterized in that it comprises: Rectifier circuit: the input terminal is connected to an AC power supply, and the input terminal is connected to a power factor correction circuit after rectifying the input AC power supply; Power factor correction circuit: the input terminal is connected to the rectifier circuit, and the power factor correction is performed on the rectified power supply, and the output terminal is connected to the series-parallel resonant inverter circuit; Series-parallel resonant inverter circuit: the input terminal is connected to a power factor correction circuit, and the power factor corrected power supply is converted into a high-frequency AC power supply suitable for the load through high-frequency resonance, and the output terminal is connected to the load. 2. The electronic ballast according to claim 1, wherein said series-parallel resonant inverter circuit comprises: Half-bridge conversion circuit: the input end is connected to the output end of the power factor correction circuit, including the first power switch tube, the second power switch tube, the first power diode, and the second power diode. The two power switch tubes are connected in series, and the first power switch tube The source of the switch tube and the drain of the second power switch tube are connected to the output of the power factor correction circuit. The poles are connected, and the gates of the two power switch tubes are connected to the drive circuit; the output end of the half-bridge conversion circuit is connected to the series-parallel resonant tank circuit; Series-parallel resonant tank circuit: the input terminal is connected to the half-bridge conversion circuit, and the output terminal is connected to the load. It is composed of the first capacitor, inductor and second capacitor connected in series. The series-parallel resonant tank circuit is connected in parallel to the drain of the second power switch tube. Between the source and the source, one end of the first capacitor is connected to the drain of the second power switch tube, one end of the second capacitor is connected to the source of the second power switch tube, and the load is connected in parallel with the second capacitor. 3. The electronic ballast according to claim 2, wherein the first power switch tube and the second power switch tube are IRFP450 type power field effect transistor MOSFET; or The first power diode and the second power diode are MUR460; or The inductance is 100μH~200μH; or The first capacitor and the second capacitor are 1nF~20nF. 4. A high-intensity gas discharge lamp control device based on the above-mentioned electronic ballast, characterized in that it includes an electronic ballast and: Drive circuit: connected with the electronic ballast and the control circuit, and executes the instructions of the control circuit to drive the electronic ballast; Control circuit: connected with the drive circuit and signal acquisition circuit, generates control signals according to the electronic ballasts and high-intensity gas discharge lamps collected by the signal acquisition circuit, and sends control instructions to the drive circuit; Signal acquisition circuit: connected with the electronic ballast, high-intensity gas discharge lamp and control circuit, and collects the working conditions of the electronic ballast and high-intensity gas discharge lamp. 5. The high-intensity gas discharge lamp control device based on the electronic ballast according to claim 4, wherein the drive circuit comprises: Voltage-controlled oscillator: the input terminal is connected to the control circuit, the output terminal is connected to the T flip-flop, the input voltage signal, and the output proportional frequency signal; T flip-flop: the input terminal is connected to the voltage-controlled oscillator, the output terminal is connected to the driver, and the signal of the voltage-controlled oscillator is divided by two to form two control signals with opposite phases; Driver: The input terminal is connected to the driver, and the output terminal is connected to the electronic ballast, including the first driver and the second driver, which control the two power switch tubes of the half-bridge conversion circuit in the electronic ballast according to the control signal output by the T flip-flop . 6. The high-intensity gas discharge lamp control device based on the electronic ballast according to claim 4, wherein the control circuit comprises: Control switch: the input end is connected to the selected state controller and the state controller group, and the output end is connected to the voltage-controlled oscillator of the driving circuit; according to the control signal of the selected state controller, the signal of the corresponding state controller in the state controller group is output to voltage controlled oscillator; Selection state controller: the input terminal is connected to the signal acquisition circuit, and according to the working conditions of the electronic ballast and the high-intensity gas discharge lamp collected by the signal acquisition circuit, corresponding control signals for selecting different state controllers are generated and output to the control switch and state controller group; State controller group: including one or more state controllers, the input terminal can be connected to the signal acquisition circuit and/or select the state controller, according to the working conditions and selection of electronic ballasts and high-intensity gas discharge lamps collected by the acquisition circuit The control signal of the state controller uses the corresponding output signal of the state controller as an output signal; the output signal is output to the control switch through the output terminal. 7. The high-intensity gas discharge lamp control device based on the electronic ballast according to claim 6, wherein the state controller group includes: Trigger controller: generate a control signal in the untriggered stage, and the output end is connected to an input end of the control switch; Start controller: generate the control signal in the start phase, the input signal includes the electronic ballast and the working condition signal of the high-intensity gas discharge lamp collected by the acquisition circuit and the control signal of the selection state controller, and the output terminal is connected to an input terminal of the control switch ; Constant power controller: It generates the control signal in the constant power stage. The input signal includes the electronic ballast and high-intensity gas discharge lamp working condition signal collected by the acquisition circuit and the control signal of the selected state controller. The output terminal is connected to one of the control switches. input. 8. The high-intensity gas discharge lamp control device based on the electronic ballast according to claim 7, wherein the starting controller comprises: Starter amplifier: it can be an error amplifier, one input terminal is connected to the signal acquisition circuit, the other input terminal is connected to the exponential voltage generator, and the output terminal is connected to the control switch; Exponential voltage generator: the input terminal is connected to the selection state controller, and the output terminal is connected to the amplifier. 9. The high-intensity gas discharge lamp control device based on the electronic ballast according to claim 7, wherein the constant power controller comprises: Constant power amplifier: one input divider, the other input is grounded through a reference voltage source, and the output is connected to a control switch; Multiplier: the input terminal is connected to the signal acquisition circuit, and the output terminal is connected to the divider; Divider: The input terminal is connected to the multiplier, and the output terminal is connected to the amplifier. 10. The high-intensity gas discharge lamp control device based on the electronic ballast according to claim 4, wherein the signal acquisition circuit comprises: Voltage processing circuit: the input terminal is connected with electronic ballast and/or high-intensity gas discharge lamp, the high-frequency AC voltage signal is collected and processed into a DC voltage signal, and the output terminal is connected with the selection state controller and the state controller group; Current processing circuit: the input terminal is connected with electronic ballast and/or high-intensity gas discharge lamp, the high-frequency AC current signal is collected and processed into a DC voltage signal, and the output terminal is connected with the selection state controller and the state controller group.

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