Power supply control system based on PWM (Pulse Width Modulation) integrated unit

Abstract

The utility model relates to the technical field of power supply control, in particular to a power supply control system based on a PWM (Pulse Width Modulation) integrated unit, which comprises a control unit, the PWM integrated unit, an energy conversion unit and an output unit, and the control unit is in signal connection with the PWM integrated unit through the signal conversion unit. According to the utility model, the control unit and the PWM integrated unit cooperate to control the output of the power supply, and the control unit adopts a programmable controller to cooperate with a GPIO pin and customize input and output ports, so that external user interfaces can be flexibly changed. In the normal operation state, the control unit and the PWM integrated unit sample the output unit and the energy conversion unit, the state of an output signal is adjusted in time, the response speed is high, and control is accurate; when an abnormity occurs, the timely control unit can timely turn off the PWM integration unit, so that the circuit is protected and the reliability of the circuit is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power control, and particularly relates to a power control system based on a PWM integrated unit. Background Art

[0002] Pulse-Width Modulation (PWM) is a technology for controlling analog circuits by changing the duty cycle of a pulse signal (i.e., the ratio of the high-level time to the entire cycle time). It is widely used in many fields from measurement, communication to power control and conversion for voltage regulation and frequency modulation, and is most prominent in various types of motor applications.

[0003] In the prior art, the generation of PWM signals can be achieved through different methods, including using the ordinary GPIO ports of a microcontroller to output, utilizing the hardware PWM output function, and building a PWM circuit with hardware. The following problems exist in the implementation process:

[0004] Using the ordinary GPIO port output method of a microcontroller (General-purpose input / output, GPIO), by programming to control the time ratio of the high and low levels output by the IO port to generate a PWM signal, any IO port can be used to generate a PWM signal, but the frequency and accuracy are limited by the performance of the CPU and the running situation of the program. At the same time, it will also occupy more CPU resources and cannot generate multiple PWM signals simultaneously.

[0005] Using the hardware PWM output function, a PWM signal is generated through a dedicated PWM module. Although it does not depend on the performance and running situation of the CPU, it can generate high-precision and high-frequency PWM signals, and can generate multiple PWM signals simultaneously without occupying too much CPU resources. However, the implementation of hardware PWM usually requires specific hardware support, and only specific IO ports can be used to generate PWM signals.

[0006] Building a PWM circuit with hardware, generating a frequency signal through a timer and a switching signal through a comparator. Although it can achieve PWM signal control, there are more circuit components, the circuit layout occupies a large area, and there is still a large room for improvement in the control accuracy of the pulse signal.

[0007] Based on the problems in the prior art, the utility model provides a power control system based on a PWM integrated unit. Summary of the Utility Model

[0008] The purpose of the utility model is to provide a power control system based on a PWM integrated unit to solve the technical problems that the generation of PWM signals in the prior art is mostly limited by hardware resource support, performance, and specific interfaces.

[0009] The technical solution of the present utility model is: A power control system based on a PWM integrated unit, including a control unit and a PWM integrated unit, with a signal conversion unit provided between the control unit and the PWM integrated unit; the control unit and the PWM integrated unit perform interactive conversion of digital signals and analog signals through the signal conversion unit; the signal conversion unit includes at least three groups of conversion circuits for interactive transmission of digital quantity setting and feedback, and analog quantity setting and feedback.

[0010] Preferably, the signal conversion unit adopts five parallel conversion circuits, namely a digital quantity setting circuit, a digital quantity feedback circuit, a first analog quantity setting circuit, a first analog quantity feedback circuit, and a second analog quantity setting circuit.

[0011] Preferably, the control unit includes a controller, a GPIO pin module, and an analog signal processing module, and the analog signal processing module and the GPIO pin module are respectively electrically connected to the controller;

[0012] Among them, the controller adopts a programmable controller; the GPIO pin module is customized through programming.

[0013] Preferably, the circuits in the PWM integrated unit are integrated and packaged, and the integrated and packaged circuits include a PWM generation circuit, a current inner loop control circuit, a switching circuit, an under-voltage protection circuit, an over-temperature protection circuit, and a feedback circuit.

[0014] Preferably, an energy conversion unit and an output unit are connected to the output end of the PWM integrated unit;

[0015] The output end of the PWM integrated unit is connected to the input end of the energy conversion unit, and the output end of the energy conversion unit is connected to the input end of the output unit to supply energy to the output unit.

[0016] Preferably, the energy conversion unit adopts one of a DC / AC conversion circuit, an AC / DC conversion circuit, a DC / DC conversion circuit, and an AC / AC conversion circuit.

[0017] Preferably, the control unit samples and detects the voltage and current signals output by the output unit.

[0018] Compared with the prior art, the advantages of the present utility model are:

[0019] (1) The utility model cooperates with a control unit and a PWM integration unit to control the power output. The control unit is signal-connected to the PWM integration unit through a signal conversion unit. Both the control unit and the PWM integration unit are provided with voltage and current feedback, and can adjust the state of the output signal in a timely manner according to the feedback, with a fast response speed, precise control, and higher reliability.

[0020] Based on the signal conversion unit for high and low level conversion, in the normal operation state of the power supply system, the control unit can adjust the state and magnitude of the output signal based on the voltage and current sampling feedback results of the output unit, adjust the output of the PWM integration unit, and can also timely turn off and control the PWM integration unit in case of abnormalities to protect the circuit and improve the circuit reliability.

[0021] (2) The control unit uses a programmable controller in cooperation with GPIO pins to customize the input and output ports, can flexibly change the external user interface, and can be customized to meet various usage requirements. Description of the Drawings

[0022] The following further describes the present utility model in conjunction with the drawings and embodiments:

[0023] Figure 1 It is a schematic circuit diagram of the power supply control system described in the present utility model;

[0024] Figure 2 It is a schematic diagram of the signal relationship between the control unit and the PWM integration unit described in the present utility model;

[0025] Figure 3 It is a schematic diagram of an embodiment of the control unit and the PWM integration unit described in the present utility model;

[0026] Figure 4 It is a schematic diagram of an embodiment of the energy conversion unit and the output unit described in the present utility model;

[0027] 1. Control unit; 2. Signal conversion unit; 3. PWM integration unit; 4. Energy conversion unit; 5. Output unit;

[0028] 21. Digital quantity given circuit; 22. Digital quantity feedback circuit; 23. First analog quantity given circuit; 24. First analog quantity feedback circuit; 25. Second analog quantity given circuit. Detailed Embodiment

[0029] The following further describes the content of the present utility model in detail in conjunction with specific embodiments:

[0030] Such as Figure 1As shown in the figure, a power control system based on a PWM integration unit includes a control unit 1, a PWM integration unit 3, an energy conversion unit 4, and an output unit 5.

[0031] The control unit 1 and the PWM integration unit 3 perform interactive conversion and transmission of digital signals and analog signals through a signal conversion unit 2. The output end of the PWM integration unit is connected to the input end of the energy conversion unit, and the output end of the energy conversion unit is connected to the input end of the output unit.

[0032] The signal conversion unit 2 includes at least three groups of conversion circuits, corresponding to performing signal conversion of digital quantity setting and feedback, analog quantity setting and feedback, and transmitting the control signal used by the control unit 1 to control and adjust the output of the PWM integration unit 3.

[0033] The control unit 1 includes a controller, a GPIO pin module, and an analog signal processing module. The analog signal processing module and the GPIO pin module are electrically connected to the controller respectively.

[0034] The controller adopts a programmable controller, including a microprocessor (CPU), a memory (ROM, RAM), a programmer, and a power supply. For example, a PLC controller, with the configured input / output being the GPIO pin module, is used to send and receive signals. Users or software can customize it through programming, and can flexibly modify the external user interface.

[0035] The PWM integration unit 3 internally integrates circuits related to PWM signals and protection circuits. The circuits are integrated and packaged, and used modularly. Existing integrated chips can be used, such as chips with model numbers UC3525, UC1846, and LM5039, or circuits built by customizing integrated packaging. The integrated packaged circuit includes a PWM generation circuit, a current inner loop control circuit, a comparator, a switch circuit, an undervoltage protection circuit, an overvoltage protection circuit, an overtemperature protection circuit, and a feedback circuit.

[0036] In an embodiment, as shown in the appendix Figure 3 As shown in the figure, the signal conversion unit 2 includes five groups of conversion circuits, namely a digital quantity setting circuit 21, a digital quantity feedback circuit 22, a first analog quantity setting circuit 23, a first analog quantity feedback circuit 24, and a second analog quantity setting circuit 25.

[0037] Digital quantity setting circuit 21: includes a first trigger and a first logic circuit. The digital signal output end of the control unit 1 is connected to the input end of the first trigger. The control unit 1 gives a GPIO output of 0 / 1, and the output end of the first trigger is connected to the input end of the first logic circuit;

[0038] Among them, the common forms of the first trigger are: rising edge trigger, falling edge trigger, high level trigger, and low level trigger.

[0039] Common forms of the first logic circuit: It can be a conversion circuit built by several logic gates such as OR gates, AND gates, NAND gates, NOR gates, etc., a logic circuit built by triodes, or a logic chip, such as the CD4072BM chip (a 2-channel 4-input OR gate chip).

[0040] The digital quantity feedback circuit 22 includes a first level conversion circuit. The common form is a level conversion chip, such as a converter of model SN74LVC4245APW, or a hardware circuit composed of triodes.

[0041] Similar to the digital quantity given circuit 21, the PWM integration unit 3 outputs an I / O feedback signal, which is converted into a signal recognizable by the control unit 1 through the first level conversion circuit. For example, the 0 / 15V low / high level signal feedback by the PWM integration unit 3 is converted into a signal with 0 corresponding to the low level and 3V corresponding to the high level, facilitating the recognition by the control unit 1.

[0042] The first analog quantity given circuit 23 includes a comparator, a second trigger, and a second logic circuit. The first analog signal output terminal of the control unit 1 is connected to the input terminal of the comparator, the output terminal of the comparator is connected to the input terminal of the second trigger, and the output terminal of the second trigger is connected to the input terminal of the second logic circuit.

[0043] After the comparator outputs a high level / low level, the analog quantity to digital quantity change is completed. It is commonly used to set the current / voltage protection level. However, when the current sampling is greater than the given analog quantity value, a high level is output, indicating overcurrent, and the control unit 1 is notified to perform a protection action. Similar to the digital quantity given circuit 21, the common form adopted by the second trigger is the same as that of the first trigger, and the common form adopted by the second logic circuit is the same as that of the first logic circuit.

[0044] The first analog quantity feedback circuit 24 includes a second level conversion circuit. The common form of the second level conversion circuit is an amplifier, which is used to sample the analog quantity signal output by the PWM integration unit 3 and perform conversion of the analog quantity signal range. For example, the analog quantity voltage range of 0 - 10V is converted into the analog quantity voltage range of 0 - 3V.

[0045] The second analog quantity given circuit 25 includes a third level conversion circuit. The common form is an amplifier, which performs conversion of the analog quantity signal range. For example, the 0 - 3V given output by the control unit 1 is converted into 0 - 10V and transmitted to the PWM integration unit 3 to control the adjustment of the output of the PWM integration unit 3.

[0046] Based on the signal conversion unit 2, high and low level conversion is performed to enable the control unit 1 to output an analog signal or a digital signal to the PWM integration unit 3, and receive the analog signal or digital signal fed back by the PWM integration unit 3. The signal transmission relationship is as shown in the appendix Figure 2 as follows.

[0047] The switch circuit in the PWM integration unit 3 provides a general-purpose shutdown port. When the power system is running, the PWM integration unit 3 is enabled or disabled by outputting high and low levels to the enable or shutdown pin / port, thereby controlling the PWM integration unit 3 to turn on or off to protect the circuit.

[0048] When the PWM integration unit 3 is working, based on the output signal of the control unit 1, the frequency of the input signal is adjusted, and the duty cycle is configured by adjusting the internal register to output a stable pulse signal. That is to say, the PWM integration unit 3 outputs a pulse signal to the energy conversion unit 4, and the switching element in the energy conversion unit 4 continuously conducts and disconnects under the action of the pulse signal to supply energy to the output unit 5.

[0049] A sampler is provided in the energy conversion unit 4 to sample the voltage and current, and the sampling result is fed back to the PWM integration unit 3. The PWM integration unit 3 determines whether to turn off according to the sampling result to protect the power devices in the circuit.

[0050] The energy conversion unit 4 is a conversion circuit in the power system, and adopts one of the DC / AC conversion circuit, AC / DC conversion circuit, DC / DC conversion circuit, and AC / AC conversion circuit.

[0051] Referring to the appendix Figure 4 , a specific implementation manner of the energy conversion unit 4 and the output unit 5 is given. The energy conversion unit 4 is set as an H-bridge. The switching elements in the H-bridge are alternately turned on or off under the action of the pulse signal, converting the direct current into an alternating current waveform output, realizing energy isolation through an isolation transformer, and transmitting the alternating current signal to the rectifier bridge in the subsequent stage. The rectifier bridge rectifies the alternating current signal into direct current to complete the DC / DC conversion. The capacitor filters the output of the rectifier bridge, making the output at the load end (resistor) close to direct current, and realizing the energy supply to the output unit 5.

[0052] The output unit 5 is a load circuit. For example, the resistive load shown in the appendix Figure 3 . The output unit 5 samples the voltage and current through a current sensor or a proportional amplifier and feeds back to the control unit 1. The control unit 1 adjusts the output signal state based on the sampling result of the output unit 5.

[0053] Compared with the prior art, the advantages of the present utility model include:

[0054] The control unit 1 uses a programmable logic controller and matches GPIO pins, which can flexibly adjust the external user interface to meet the requirements of various usage scenarios; the control unit 1 and the PWM integration unit 3 perform signal conversion and transmission based on the signal conversion unit 2, and perform high and low level conversion through the signal conversion unit 2. The control unit 1 can not only control the working state (on or off) of the PWM integration unit 3 to protect the circuit, but also adjust the state and magnitude of the output signal based on the voltage and current sampling feedback results of the output unit 5.

[0055] The PWM integration unit 3 integrates and packages a PWM generation circuit, a current inner loop control circuit, a switching circuit, and various protection circuits, etc. The internal switching circuit provides a general-purpose shutdown port, which can turn off the PWM integration unit 3 at the control unit 1 end, enabling remote control, with a higher circuit safety factor and more reliable circuit.

[0056] The PWM integration unit 3 has an integrated package setting, which occupies a small circuit layout area, can increase the number according to requirements, and generate multiple PWM signals; an internal switching circuit is provided, which can be turned off in a timely manner (including remote shutdown) in case of an abnormality, reducing the risk of device damage, and is overall precisely controllable; multiple protection circuits are provided inside, which can avoid problems such as overcurrent, overheating, and input interference, effectively improving the reliability and stability of the power supply system.

[0057] The control unit 1 and the PWM integration unit 3 are signal-connected through the signal conversion unit 2. With their cooperation, the power output is controlled, and both are provided with voltage and current feedback, which can adjust the state of the output signal in a timely manner according to the feedback, with a fast response speed, precise control, and higher reliability.

[0058] The above embodiments are only for explaining the technical concept and characteristics of the present invention, and their purpose is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly, and cannot be used to limit the protection scope of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to include all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. A power control system based on a PWM integrated unit, characterized in that, It includes a control unit and a PWM integration unit, and a signal conversion unit is arranged between the control unit and the PWM integration unit; The control unit and the PWM integration unit perform interactive conversion between digital signals and analog signals through the signal conversion unit; The signal conversion unit includes at least three groups of conversion circuits for performing interactive transmission of digital quantity setting and feedback, and analog quantity setting and feedback.

2. The power control system based on a PWM integration unit according to claim 1, wherein The signal conversion unit adopts five parallel conversion circuits, namely a digital quantity setting circuit, a digital quantity feedback circuit, a first analog quantity setting circuit, a first analog quantity feedback circuit, and a second analog quantity setting circuit.

3. The power control system based on a PWM integration unit according to claim 2, characterized in that, The control unit includes a controller, a GPIO pin module, and an analog signal processing module, and the analog signal processing module and the GPIO pin module are respectively electrically connected to the controller; Among them, the controller adopts a programmable controller; the GPIO pin module is customized through programming.

4. A power control system based on a PWM integration unit according to claim 1, characterized in that, The circuits in the PWM integration unit are integrally packaged, and the integrally packaged circuits include a PWM generation circuit, a current inner loop control circuit, a switching circuit, an undervoltage protection circuit, an overtemperature protection circuit, and a feedback circuit.

5. A power control system based on a PWM integrated unit according to claim 1, characterized in that, An energy conversion unit and an output unit are connected to the output end of the PWM integration unit; The output end of the PWM integration unit is connected to the input end of the energy conversion unit, and the output end of the energy conversion unit is connected to the input end of the output unit to supply energy to the output unit.

6. The power control system based on a PWM integrated unit according to claim 5, wherein The energy conversion unit adopts one of a DC / AC conversion circuit, an AC / DC conversion circuit, a DC / DC conversion circuit, and an AC / AC conversion circuit.

7. A power control system based on a PWM integrated unit according to claim 5, characterized in that, The control unit samples and detects the voltage and current signals output by the output unit.

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