CN101420811B - Ballast for automotive HID lamps based on digital control to realize soft-switching PWM technology - Google Patents

Abstract

The invention discloses a vehicle HID lamp ballast which realizes a soft-switching PWM technology based on digital control, comprising a power management module, a flyback DC converter, a main core module, a current auxiliary network, a DC-AC converter and a voltage booster circuit; the vehicle HID lamp ballast is characterized in that the main core module comprises a single chip microcomputer, an I/O interface and an A/D conversion module which are respectively connected with input terminals of the single chip microcomputer and a digital PWM module which is connected with the output terminal of the single-chip microcomputer; the vehicle HID lamp ballast further comprises the flyback DC converter which is connected between the power management module and the current auxiliary network and a drain-source voltage sampling circuit which is connected between a MOS switch tube of the flyback DC converter and the I/O interface; the output terminals of the digital PWM module are respectively connected with a gate of the MOS switch tube of the flyback DC converter and the control input terminal of the DC-AC converter. A drive signal of the flyback DC converter is controlled in an MCU digital control method, thereby realizing the use of the soft-switching PWM technology to control an HID lamp. The vehicle HID lamp ballast can effectively simplify the hardware structure of the vehicle HID ballast and reduce the overall power consumption and the heat value; and the vehicle HID lamp ballast can maintain the very high conversion efficiency within a wide change range of the voltage of a vehicle power supply.

Description

Ballast for automotive HID lamps based on digital control to realize soft-switching PWM technology

technical field

The invention relates to an electronic ballast for HID lamps for vehicles which realizes soft switching PWM (pulse width modulation) technology based on digital control.

Background technique

Xenon HID (High Intensity Discharge) high-pressure gas discharge lamp has the advantages of high luminous efficiency, good color rendering, and long life. The 35W HID lamp has received great attention and application in the automotive field.

The electronic ballast usually used in automotive HID lamps has a structure as shown in Figure 1, which mainly includes a power management module 10, a DC-DC converter 11, a boost circuit 12, a DC-AC converter 13, an MCU 14, and a HID Lighting device 15. Among them, the power management module 10 is connected with the car battery 12V, including filtering and reverse polarity protection of the input battery voltage; the DC-DC converter 11 converts the battery voltage into 85V DC voltage; The kilovolt voltage is used as the input of the high-voltage ignition device; the DC-AC converter 13 converts the 85V DC voltage into a low-frequency alternating square wave, which is provided to the HID lamp; the MCU 14 is the monitoring and management center of the entire system.

The above electronic ballast for HID lamps for vehicles does not use soft-switching PWM technology, so that the switching tube has a lot of noise, the calorific value of the ballast device increases, and the conversion efficiency of the circuit is low. The harsh operating environment has extremely high requirements on the conversion efficiency and calorific value of the ballast device; in addition, this type of HID ballast uses a large number of components, which has the problems of large volume and high cost.

In addition, some developed soft-switching PWM technologies are implemented based on hardware, and it is difficult to maintain high conversion efficiency in a wide range of vehicle power supply voltage changes.

Contents of the invention

The object of the present invention is to solve the above-mentioned problems existing in the prior art and provide an electronic ballast for HID lamps for vehicles based on digital control to realize soft-switching PWM technology, so that the temperature rise of the electronic ballast is low and the voltage of the vehicle power supply is low. The conversion efficiency is high and the reliability is good within a wide variation range, and it is beneficial to reduce volume and cost.

In order to achieve the above object, the present invention provides a HID lamp ballast for vehicles based on digital control to realize soft switching PWM technology, including a power management module, a DC-DC converter, a main core module, a current auxiliary network, and a DC-AC converter , boost circuit; its characteristics are,

It also includes a MOS switch tube drain-source voltage sampling circuit;

The DC-DC converter is composed of a flyback DC converter; the flyback DC converter is connected between the power management module and the current auxiliary network;

Described main core module comprises a MCU or DSP single-chip microcomputer, an I/O interface, an A/D conversion module and a digital PWM module; Described I/O interface and A/D conversion module are respectively connected with the input of single-chip microcomputer Terminal connection, the input terminal of described A/D conversion module is connected with flyback type DC converter output terminal; The output terminal of described single-chip microcomputer is connected with the input terminal of digital PWM module; The output terminal of described digital PWM module respectively connected to the control input terminals of the flyback DC converter and the DC-AC converter;

The MOS switch tube drain-source voltage sampling circuit is connected between the flyback DC converter and the I/O interface of the main core module;

The output end of the current auxiliary network is connected to the input end of the DC-AC converter, and the output end of the DC-AC converter is respectively connected to the high-voltage ignition device and the high-pressure gas discharge lamp;

The input end of the boost circuit is connected to the output end of the flyback DC converter, and the output end of the boost circuit is connected to the input end of the high voltage ignition device.

The above-mentioned automotive HID lamp ballast based on digital control to realize soft-switching PWM technology, wherein the flyback DC converter is mainly composed of a transformer and a MOS switch tube connected to one end of the primary coil of the transformer; One end of the primary coil of the transformer and the connection point of the MOS switch tube are connected to the input end of the drain-source voltage sampling circuit through wires; one end of the secondary coil of the transformer is connected to the input end of the booster circuit.

The above-mentioned HID lamp ballast for vehicles based on digital control to realize soft-switching PWM technology, wherein, an output terminal of the digital PWM module of the main core module is connected with the MOS switch tube of the flyback DC converter the gate connection.

The aforementioned HID lamp ballast for vehicles based on digital control to realize soft-switching PWM technology, wherein the input terminal of the drain-source voltage sampling circuit of the MOS switch tube is connected to the drain of the MOS switch tube in the flyback DC converter. The source has two poles, and its output terminal is connected to the I/O interface.

The above-mentioned automotive HID lamp ballast based on digital control to realize soft-switching PWM technology, wherein the drain MOS switching tube source voltage sampling circuit is composed of two resistors connected in series, and the connection point of the two resistors is connected by a wire and The I/O interface connection of the main core module.

The above-mentioned HID lamp ballast for vehicles based on digital control to realize soft-switching PWM technology, wherein the MOS switching tube drain-source voltage sampling circuit is composed of two resistors connected in series and an operational amplifier, and the connection of the two resistors The point is connected with the input terminal of the operational amplifier through wires, and the output terminal of the operational amplifier is connected with the I/O interface of the main core module.

The aforementioned HID lamp ballast for vehicles based on digital control and realizing soft-switching PWM technology, wherein, the input terminal of the power management module is connected to the storage battery.

The present invention is based on digital control to realize the soft-switching PWM technology of the automotive HID lamp ballast because the above technical scheme is adopted. The technology has the following advantages:

1. The realization of digital settable and intelligent control: Through program parameter setting, the zero-crossing detection point of the drain-source voltage of the main MOS switch tube in the flyback DC converter under different input voltages can be set, so as to be able to Enables soft switching over a wider range, enabling electronic ballast systems to achieve higher efficiency over a wider range of input battery voltages.

2. Simplify the hardware structure and reduce the overall power consumption. The hardware circuit of the soft-switching PWM technology based on digital control is simple, which reduces the number of components on the PCB board, reduces the size of the electronic ballast, and reduces the cost of the ballast. The power consumption and heat generation of the system; the headlight system of the car is close to the engine compartment. This extremely harsh working environment has very strict requirements on the electronic ballast system of the HID lamp used in the car. The reduction of the size and heat generation of the electronic ballast is the It is very advantageous, and the simplification of the hardware also reduces the cost.

3. Realize the soft switching operation of the main switching tube on the primary side and the rectifying diode on the secondary side of the transformer in the DC-DC converter, reduce the noise of the switching tube, effectively avoid magnetic flux saturation, and keep the HID lamp within the fluctuation range of the battery voltage Stable work; the temperature rise of the entire ballast system is reduced, the energy consumption is reduced, the conversion efficiency is increased, and the circuit is more reliable; the efficiency can reach 87%.

Description of drawings

Concrete features and performances of the present invention are further described by the following examples and accompanying drawings.

FIG. 1 is a structural block diagram of an electronic ballast commonly used in a vehicle HID lamp in the prior art.

Fig. 2 is an electrical block diagram of the HID lamp ballast for vehicles which realizes soft switching PWM technology based on digital control according to the present invention.

Fig. 3 is an overall electrical block diagram of an embodiment of a drain-source voltage sampling circuit in a vehicle HID lamp ballast that realizes soft-switching PWM technology based on digital control in the present invention.

Fig. 4 is an overall electrical block diagram of another embodiment of the drain-source voltage sampling circuit in the vehicle HID lamp ballast for realizing soft-switching PWM technology based on digital control in the present invention.

Detailed ways

Please refer to FIG. 2 , which is an electrical block diagram of the HID lamp ballast for vehicles implementing soft-switching PWM technology based on digital control according to the present invention. The electronic ballast for vehicle HID lamps based on digital control to realize soft switching PWM technology in the present invention includes a power management module 20, a flyback DC converter 21, a boost circuit 22, a current auxiliary network 23, a DC-AC converter 24, A drain-source voltage sampling circuit 25 and a main core module 26 .

The input end of the power management module 20 is connected to the storage battery. Its function is to sample, filter and monitor the battery voltage.

The main core module 26 includes an MCU or DSP microcontroller 261 , an I/O interface 262 , an A/D conversion module 263 , and a digital PWM module 264 . The I/O interface 262 and the A/D conversion module 263 are respectively connected to the input end of the single-chip microcomputer 261, and the output end of the single-chip microcomputer 261 is connected to the input end of the digital PWM module 264; Processing is carried out to control the switching frequency and duty cycle of the MOS switching tube of the flyback DC converter to control the HID lamp.

The flyback DC converter 21 is connected between the power management module 20 and the current auxiliary network 23; in a steady state, the function of this circuit module is to raise the battery voltage to 85V.

The output end of the current auxiliary network 23 is connected to the input end of the DC-AC converter 24, and the output end of the DC-AC converter 24 is respectively connected to the high-voltage ignition device 271 of the load 27 and the high-pressure gas discharge lamp 272; The function of the circuit module is to provide extra current to the lamp after the lamp is started, so as to ensure that the temperature of the lamp electrode can rise rapidly, so as to prevent the lamp from working in the glow discharge state or extinguishing for a long time after the lamp is started; Provide energy to the lamp for a period of time, and do not participate in the work during normal operation.

The input end of the booster circuit 22 is connected with the output end of the flyback DC converter 21, and the output end of the booster circuit 22 is connected with the input end of the high-voltage ignition device 271; it will generate a high voltage of about 800V, output To the high-voltage ignition device 271, the high-voltage ignition device 271 generates a voltage of several thousand volts to tens of thousand volts to light the HID lamp.

Described drain-source voltage sampling circuit 25 is connected between the source-drain end of the MOS switching tube in flyback DC converter 21 and the I/O interface 262 of main core module; The effect of drain-source voltage sampling circuit 25 is to obtain The drain-source voltage sampling signal is output to the main core module.

The input end of the A/D conversion module 263 of the main core module is connected with the output end of the flyback DC converter 21;

The output terminals of the digital PWM module 264 of the main core module are respectively connected to the gate of the MOS switch in the flyback DC converter 21 and the control input terminal of the DC-AC converter 24 .

In an electronic ballast for a xenon gas high-pressure discharge lamp (HID) for a vehicle of the present invention, the flyback DC converter 21 is mainly composed of a transformer T1 and a MOS switch tube Q1 connected to one end of the primary coil of the transformer; One end of the transformer primary coil and the connection point of the MOS switch tube are connected to the input terminal of the drain-source voltage sampling circuit through a wire. In this embodiment, the input terminal of the drain-source voltage sampling circuit is connected to the flyback DC The drain and source poles of the switching tube in the converter are connected to the output terminal of the I/O interface; one terminal of the secondary coil of the transformer is connected to the input terminal of the boost circuit. An output end of the digital PWM module of the main core module is connected to the gate of the MOS switch tube of the flyback DC converter.

The present invention uses the drain-source voltage sampling circuit 25 to sample the voltage of the drain-source poles of the switching tube in the flyback DC converter 21, and introduces the sampling signal into the I/O port or the A/D port of the main core module 26, and passes the The digital control method is used to control the driving signal of the switching tube in the module 21 to realize the soft switching PWM technology.

Please refer to FIG. 3 , which is an overall electrical block diagram of an embodiment of a drain-source voltage sampling circuit in a vehicle HID lamp ballast that implements soft-switching PWM technology based on digital control in the present invention. The electronic ballast for vehicle HID lamps based on digital control to realize soft switching PWM technology in the present invention includes a power management module 30, a flyback DC converter 31, a boost circuit 32, a current auxiliary network 33, a DC-AC converter 34, A drain-source voltage sampling circuit 35 and a main core module 36 .

The main core module 36 includes a microcontroller 361 , an I/O interface 362 , an A/D conversion module 363 , and a digital PWM module 364 . The I/O interface 362 and the A/D conversion module 363 are respectively connected to the input end of the single-chip microcomputer 361 , and the output end of the single-chip microcomputer 361 is connected to the input end of the digital PWM module 364 . The drain-source voltage sampling circuit 35 described in this embodiment is composed of a resistor R1 and a resistor R2 connected in series. One end of the resistor R1 is connected to one end of the resistor R2 and then connected to the I/O port of the main core module 36. The resistor R1 The other end of the resistor R2 is connected to the drain of the switch tube of the flyback DC converter 31, and the other end of the resistor R2 is connected to the source of the switch tube.

Please refer to FIG. 4 , which is an overall electrical block diagram of another embodiment of the drain-source voltage sampling circuit in the vehicle HID lamp ballast for realizing soft-switching PWM technology based on digital control in the present invention. The electronic ballast for vehicle HID lamps based on digital control to realize soft switching PWM technology in the present invention includes a power management module 40, a flyback DC converter 41, a boost circuit 42, a current auxiliary network 43, a DC-AC converter 44, A drain-source voltage sampling circuit 45 and a main core module 46 .

The main core module 46 includes a microcontroller 461 , an I/O interface 462 , an A/D conversion module 463 , and a digital PWM module 464 . The I/O interface 462 and the A/D conversion module 463 are respectively connected to the input end of the single-chip microcomputer 461 , and the output end of the single-chip microcomputer 461 is connected to the input end of the digital PWM module 464 .

The drain-source voltage sampling circuit 45 described in this embodiment includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, and an operational amplifier OP1. One end of the resistor R1 is connected to one end of the resistor R2 and then connected to one end of the resistor R3. The other end of the resistor R1 is connected to the drain of the switch tube of the flyback DC converter 41, the other end of the resistor R2 is connected to the source of the switch tube of the flyback DC converter 41, and the other end of the resistor R3 is connected to the operational amplifier OP1 The positive input terminal of the resistor R4 is connected to the negative input terminal of the operational amplifier OP1, and the other terminal of the resistor R4 is connected to the output terminal of the operational amplifier OP1 (resistor R4 can also be a short circuit), and the output terminal of the operational amplifier OP1 is connected to 46 I/O port or A/D port.

When it is detected that the drain-source voltage of the switching tube in the flyback DC converter 41 drops to almost zero, the main core module 46 controls the digital PWM module to output a high level to turn on the switching tube.

The present invention is an electronic ballast for HID lamps for vehicles based on digital control to realize soft-switching PWM technology. The digital control method of MCU is used to control the driving signal of the flyback DC converter, and the soft-switching PWM technology is used to control the HID lamp. It can effectively simplify the hardware structure of the automotive HID ballast, and reduce the overall power consumption and heat generation; it can maintain a high conversion efficiency within a wide range of vehicle power supply voltage. And it is beneficial to reduce volume and cost.

Claims (7)

1. the Vehicular HID lamp ballast based on digital control realization soft switch PWM technique comprises power management module, DC-DC converter, main nucleus module, current auxiliary network, direct-current-alternating-current converter, booster circuit; It is characterized in that,

Also comprise a MOS switching tube drain-source voltage sample circuit;

Described DC-DC converter is made up of the inverse-excitation type DC converter; Described inverse-excitation type DC converter is connected between power management module and the current auxiliary network;

Described main nucleus module comprises a MCU or DSP single-chip microcomputer, an I/O interface, an A/D modular converter and a digital PWM module; Described I/O interface is connected with the input of single-chip microcomputer respectively with the A/D modular converter, and the input of described A/D modular converter is connected with inverse-excitation type DC converter output; The output of described single-chip microcomputer is connected with the input of digital PWM module; The output of described digital PWM module is connected with the control input end of inverse-excitation type DC converter and direct-current-alternating-current converter respectively;

Described MOS switching tube drain-source voltage sample circuit is connected between the I/O interface of inverse-excitation type DC converter and main nucleus module;

The output of described current auxiliary network is connected with the input of direct-current-alternating-current converter, and the output of this direct-current-alternating-current converter is connected with high-voltage gas discharging light with high-voltage ignition device respectively;

The input of described booster circuit is connected with the output of inverse-excitation type DC converter, and the output of this booster circuit is connected with the input of high-voltage ignition device.

2. a kind of Vehicular HID lamp ballast according to claim 1 based on digital control realization soft switch PWM technique; It is characterized in that described inverse-excitation type DC converter mainly is made up of the MOS switching tube that a transformer and is connected this transformer one end; Described transformer one end and MOS switching tube tie point are wired to the input of drain-source voltage sample circuit; Described transformer secondary output coil one end connects the input of booster circuit.

3. a kind of Vehicular HID lamp ballast according to claim 2 based on digital control realization soft switch PWM technique; It is characterized in that an output of the digital PWM module of described main nucleus module is connected with the grid of the MOS switching tube of described inverse-excitation type DC converter.

4. a kind of Vehicular HID lamp ballast according to claim 1 based on digital control realization soft switch PWM technique; It is characterized in that; Described its input of MOS switching tube drain-source voltage sample circuit is connected on drain-source the two poles of the earth of MOS switching tube in the inverse-excitation type DC converter, and its output is connected with the I/O interface.

5. according to claim 1 or 4 described a kind of Vehicular HID lamp ballasts based on digital control realization soft switch PWM technique; It is characterized in that; Described MOS switching tube drain-source voltage sample circuit is made up of the resistance of two series connection, and the tie point of this two resistance is connected with the I/O interface of main nucleus module through lead.

6. according to claim 1 or 4 described a kind of Vehicular HID lamp ballasts based on digital control realization soft switch PWM technique; It is characterized in that; Described MOS switching tube drain-source voltage sample circuit is made up of the resistance and an operational amplifier of two series connection; The tie point of this two resistance is connected with the input of operational amplifier through lead, and the output of this operational amplifier is connected with the I/O interface of main nucleus module.

7. a kind of Vehicular HID lamp ballast based on digital control realization soft switch PWM technique according to claim 1 is characterized in that the input of described power management module is connected with storage battery.

Images