阅读说明：本技术 一种数字式发电机调压控制电路 (Digital generator voltage regulation control circuit ) 是由 王美靖 张学铭 孙铭礁 张宏超 李晓多 闫智洲 于 2020-12-16 设计创作，主要内容包括：本发明属于重型车辆电子控制单元中的发电机控制技术领域,涉及一种数字式发电机调压控制电路。该调压控制电路包括电容C-1、MOS管Q1、MOS管Q2、续流二极管D1、续流二极管D2、开关导通电阻R2、开关导通电阻R3、滤波上拉电阻R1、励磁绕组。本发明通过设计数字式发电机调压控制电路,解决以往单纯依靠模拟器件搭建的模拟调压电路不能实现发电机准确调压及器件工作可靠性低等问题,从而将发电控制器向数字化、可视化等技术方向引领,从而达到产品更新换代；依据GJB298等相关标准规定,为满足后端低压负载设备可靠工作,低压28V三相整流发电机输出电压就必须满足在28±0.7V范围内。(The invention belongs to the technical field of generator control in an electronic control unit of a heavy vehicle, and relates to a digital generator voltage regulation control circuit. The voltage regulation control circuit comprises a capacitor C 1 The power supply comprises a MOS transistor Q1, a MOS transistor Q2, a freewheeling diode D1, a freewheeling diode D2, a switch on-resistance R2, a switch on-resistance R3, a filter pull-up resistance R1 and an excitation winding. According to the invention, by designing the digital generator voltage regulation control circuit, the problems that the accurate voltage regulation of the generator cannot be realized by the traditional analog voltage regulation circuit which is built by only depending on an analog device, the working reliability of the device is low and the like are solved, so that the power generation controller is led to the technical directions of digitization, visualization and the like, and the product is updated and updated; according to the relevant standards such as GJB298 and the like, in order to meet the requirement of reliable operation of rear-end low-voltage load equipment, the output voltage of a low-voltage 28V three-phase rectification generator is required to be within the range of 28 +/-0.7V.)

1. A voltage regulation control circuit of a digital generator is characterized by comprising a capacitor C₁The power supply comprises an MOS tube Q1, an MOS tube Q2, a freewheeling diode D1, a freewheeling diode D2, a switch on-resistance R2, a switch on-resistance R3, a filter pull-up resistance R1 and an excitation winding;

capacitor C₁Is connected with the first end of the filter pull-up resistor R1 and is commonly grounded, the second end of the filter pull-up resistor R1 and the second end of the freewheeling diode D2 are connected with the positive pole of the storage battery and the positive pole of the exciter, and a capacitor C is connected with the second end of the filter pull-up resistor R1 and the second end of the freewheeling diode D2₁The second end of the transistor Q2 is connected with the drain electrode of a MOS tube Q1, the source electrode of the MOS tube Q1 is connected with the first end of the excitation winding and is connected with the second end of a switch on-resistance R2 and the second end of a freewheeling diode D1, the gate electrode of the MOS tube Q1 is connected with the PWM pin of the single chip microcomputer, and the drain electrode of the MOS tube Q2 is connected with the second end of the excitation winding and is connected with the first end of a freewheeling diode D2. The gate of the transistor Q2 is connected with the PWM pin of the single chip, the source of the transistor Q2 is connected with the second end of the switch on-resistance R3 and the first end of the freewheeling diode D1, and the two ends are connected to the ground. Meanwhile, the first end of the switch on-resistance R2 is connected with the PWM pin of the single chip microcomputer, and the first end of the switch on-resistance R3 is connected with the PWM pin of the single chip microcomputer.

2. The voltage-regulating control circuit of the digital generator according to claim 1, wherein the MOS transistor Q1 is controlled by a single-chip microcomputer IO port, and when the feedback voltage exceeds the upper limit voltage set value, the single-chip microcomputer IO port controls the MOS transistor Q1 to be turned off; when the feedback voltage is lower than the upper limit voltage set value, the IO port of the single chip microcomputer controls the MOS tube Q1 to be switched on.

3. The voltage regulation control circuit of claim 2, wherein the turn-off delay time of the MOS transistor Q1 is not more than 1 PWM switching period.

4. The voltage regulation control circuit of the digital generator as claimed in claim 1, wherein the MOS transistor Q2 is controlled by a single chip capture comparison unit.

Technical Field

The invention belongs to the technical field of generator control in an electronic control unit of a heavy vehicle, and relates to a digital generator voltage regulation control circuit.

Background

With the gradual increase of the informatization degree and the digitization degree of the vehicle, the load power of the vehicle is continuously increased. The vehicle-mounted auxiliary power supply is an independent control power supply which is set up for meeting requirements of high-power electric equipment and an upper weapon system, and the traditional vehicle-mounted power supply generally comprises an engine, a generator and a power generation controller. The composition diagram is shown in fig. 1.

The low-voltage three-phase rectifier generator has the technical advantages of low price, reliable work, mature technology, high power density and the like, and the low-voltage three-phase rectifier generator and the vehicle-mounted power supply product of the analog generation controller are assembled on a large scale in the current real vehicle project. However, as the degree of vehicle informatization and digitization is continuously improved, the power generation controller formed by the analog circuit cannot meet the requirements, and some necessary functions of acquisition, communication and overload protection are lacked. The important point is that the analog device has poor working stability, the voltage regulating range is too wide and is not easy to control, which may cause abnormal working of the back-end load.

Disclosure of Invention

In order to solve the problems, the invention provides a voltage regulation control circuit of a digital generator, which can well solve the defects of too wide voltage regulation range, difficult control and the like of an analog device by combining with the digital control of a single chip microcomputer.

The technical scheme of the invention is as follows:

the invention builds a digital generator voltage regulation control circuit, and can well solve the defects of too wide voltage regulation range, difficult control and the like of an analog device by combining with the digital control of a single chip microcomputer. The control circuit is simple in thought, high in practicability and universality, realizes digital control of power generation, and improves accuracy, safety, reliability and digital design of a voltage regulating function of the power generation controller to a certain extent.

The invention provides a voltage regulation control circuit of a digital generator, which comprises a capacitor C₁MOS transistor Q1, MOS transistor Q2, freewheeling diode D1,A freewheeling diode D2, a switch on-resistance R2, a switch on-resistance R3, a filter pull-up resistance R1 and an excitation winding;

capacitor C₁Is connected with the first end of the filter pull-up resistor R1 and is commonly grounded, the second end of the filter pull-up resistor R1 and the second end of the freewheeling diode D2 are connected with the positive pole of the storage battery and the positive pole of the exciter, and a capacitor C is connected with the second end of the filter pull-up resistor R1 and the second end of the freewheeling diode D2₁The second end of the transistor Q2 is connected with the drain electrode of a MOS tube Q1, the source electrode of the MOS tube Q1 is connected with the first end of the excitation winding and is connected with the second end of a switch on-resistance R2 and the second end of a freewheeling diode D1, the gate electrode of the MOS tube Q1 is connected with the PWM pin of the single chip microcomputer, and the drain electrode of the MOS tube Q2 is connected with the second end of the excitation winding and is connected with the first end of a freewheeling diode D2. The gate of the MOS transistor Q2 is connected with the PWM pin of the singlechip, and the source of the MOS transistor Q2 is connected with the second end of the switch on-resistance R3 and the first end of the freewheeling diode D1 and is commonly connected to the ground. Meanwhile, the first end of the switch on-resistance R2 is connected with the PWM pin of the single chip microcomputer, and the first end of the switch on-resistance R3 is connected with the PWM pin of the single chip microcomputer.

Further, the MOS tube Q1 is controlled by an IO port of the single chip microcomputer, and when the feedback voltage exceeds an upper limit voltage set value, the IO port of the single chip microcomputer controls the MOS tube Q1 to be turned off; when the feedback voltage is lower than the upper limit voltage set value, the IO port of the single chip microcomputer controls the MOS tube Q1 to be switched on.

Further, the turn-off delay time of the MOS transistor Q1 is not more than 1 PWM switching period.

Further, the MOS tube Q2 is controlled by the single chip capture comparison unit.

The invention takes the output voltage regulation control of a low-voltage 28V three-phase rectification generator in a vehicle-mounted auxiliary engine power supply as the background, solves the problems that the accurate voltage regulation of the generator cannot be realized and the working reliability of the device is low by designing a digital generator voltage regulation control circuit which is built by only depending on an analog device in the prior art, and the like, and leads a power generation controller to the technical direction of digitization, visualization and the like, thereby achieving the update and the replacement of products. According to the relevant standards such as GJB298 and the like, in order to meet the requirement of reliable operation of rear-end low-voltage load equipment, the output voltage of a low-voltage 28V three-phase rectification generator is required to be within the range of 28 +/-0.7V.

Drawings

FIG. 1 is a functional relationship diagram of an engine, a generator, and a power generation controller;

fig. 2 shows an excitation power circuit, (a) in a single-diode freewheeling state, and (b) in a dual-diode freewheeling state.

Fig. 3 is a block diagram of a driving algorithm of the switching tube, and (a) a PWM control flow of the Q1 tube, and (b) a PWM control flow of the Q2 tube.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The digital generator voltage regulation control circuit is integrated on a main power board of the power generation controller and is mainly used for realizing direct-current voltage detection, load current detection, exciting current detection and switching tube PWM driving output. The PWM control of the switching tube is the most main function of the voltage regulation control circuit of the generator, two PWM outputs are designed according to the scheme, two switching tubes of the excitation circuit are respectively controlled, and a power circuit is shown in figure 2.

The digital generator voltage regulation control circuit includes: capacitor C1, MOS pipe Q1, MOS pipe Q2, freewheeling diode D1, freewheeling diode D2, switch on-resistance R3, filter pull-up resistance R1 and excitation winding. The capacitor C1 and the filter pull-up resistor R1 filter the excitation power supply, the MOS tube Q1 and the MOS tube Q2 play a role in switching regulation, the output voltage of the generator is guaranteed to be within a range of 28 +/-0.7V, the diode D1 and the diode D2 play a role in follow current protection, and meanwhile, the voltage regulation process is accelerated.

Connection relation: the first end of the capacitor C1 is connected with the first end of the filter pull-up resistor R1 and is commonly grounded, and the second end of the capacitor C1 is connected with the second end of the filter pull-up resistor R1 and the second end of the freewheeling diode D2 and is also connected with the positive pole of the storage battery and the positive pole of the exciter. The second end of the capacitor C1 is connected with the drain of a MOS tube Q1, the source of the MOS tube Q1 is connected with the first end of the excitation winding and is connected with the second end of a switch on-resistance R2 and the second end of a freewheeling diode D1, and the gate of the MOS tube Q1 is connected with the PWM pin of the single chip microcomputer. The drain electrode of the MOS tube Q2 is connected with the second end of the excitation winding and is also connected with the first end of the freewheeling diode D2. The gate of the MOS transistor Q2 is connected with the PWM pin of the singlechip, and the source of the MOS transistor Q2 is connected with the second end of the switch on-resistance R3 and the first end of the freewheeling diode D1 and is commonly connected with the ground. Meanwhile, the first end of the switch on-resistance R2 is connected with the PWM pin of the single chip microcomputer, and the first end of the switch on-resistance R3 is connected with the PWM pin of the single chip microcomputer.

When the voltage regulator normally works, MOS pipe Q1 switches on, and the current is through MOS pipe Q1 chopper control, and when MOS pipe Q2 switched on, on the direct current voltage loading excitation winding after the exciter rectification, exciting current rose, and the current trend: the storage battery or exciter is Q1-the excitation winding is Q2-ground; when the MOS transistor Q2 is turned off, the exciting current diode D2 continues to flow, and the current trend is: the battery or exciter-MOS tube Q1-field winding-freewheeling diode D2-battery or exciter-as shown in FIG. 2(a), since the short voltage from the field winding is zero, the field current is reduced due to the internal resistance of the field winding and the self-inductance of the field winding.

When the output voltage overshoot exceeds the upper limit, it is required to rapidly reduce the exciting current to reduce the overshoot of the system output voltage. At this time, the method of reducing the exciting current by only turning off the MOS transistor Q2 may not meet the requirement, if the MOS transistor Q1 and the MOS transistor Q2 are both turned off, the exciting current freewheels through the diode D1\ D2, as shown in fig. 2(b), at this time, the voltage applied to the exciting winding is negative and positive, the exciting current is rapidly reduced under the action of the reverse voltage, until the voltage is reduced to a set value, the Q1 is turned on again, and the Q2 transistor enters the PWM state. The current trend is as follows: ground-MOS transistor Q1-field winding-field current passes through diode D2-battery or exciter.

According to the functional requirements, the driving logic of two switching tubes is designed as shown in fig. 3.

The MOS tube Q1 is controlled by an IO port of the single chip microcomputer, and is turned off only after the voltage exceeds an upper limit set value, and the turn-off delay time is not more than 1 PWM switching period. The MOS transistor Q1 is controlled by comparing the upper limit voltage value with the feedback voltage, and is turned off when the upper limit voltage value is greater than a set value and turned on when the upper limit voltage value is less than the set value, and the control block diagram is shown in fig. 3 (a). The MOS tube Q2 is controlled by the single chip capture comparison unit, the duty ratio is updated in each PWM period, and the calculation of the Q2 tube duty ratio is shown in figure 3 (b). The given voltage and the feedback voltage are subjected to difference to obtain error voltage, the error voltage is output through a PI regulator and is added with a proportional or differential result of a load current feedback value to obtain an exciting current given value; and after subtracting the feedback value from the given exciting current value, performing PI regulation, wherein the output of the PI regulator is a timer comparison value corresponding to the duty ratio of a Q1 tube. And then waiting for the corresponding PWM port output level change after the timer reaches the value. And updating the comparison value of the timer by each control period to realize pulse width modulation.

Effects of the invention

The circuit design is subjected to strict environment and electromagnetic compatibility tests, a control algorithm is fully tested in a rack debugging process, the voltage regulation control requirement of the current three-phase rectification generator is met, the digital design and overload overvoltage protection control of the vehicle-mounted power supply are well realized, the complexity of the circuit design is reduced, the hardware resource and the production cost of a CPU (Central processing Unit) are saved, and the serialization, the generalization and the modularization of the design are realized.