阅读说明：本技术 一种基于电力传输系统的变压单元 (Transformation unit based on power transmission system ) 是由 朱文廷 周观金 王俊 于 2020-08-12 设计创作，主要内容包括：本发明涉及电力计量技术领域,尤其涉及一种基于电力传输系统的变压单元,包括：整流电路,用以将交流电转化为直流电输出；滤波电路,连接所述整流电路,用以对所述直流电做滤波处理以形成一滤波信号；降压电路,用以接收所述滤波信号,并将所述滤波信号降压至预定信号输出；其中,所述降压电路包括：第一集成装置；第四二极管,所述第四二极管的正向端接地,所述第四二极管的反向端连接所述第一集成装置的源极；第二电感,输入端连接所述第一集成装置的源极,输出端连接所述变压单元的输出端。(The invention relates to the technical field of electric power measurement, in particular to a transformation unit based on a power transmission system, which comprises: the rectifying circuit is used for converting alternating current into direct current and outputting the direct current; the filter circuit is connected with the rectifying circuit and is used for filtering the direct current to form a filter signal; the voltage reduction circuit is used for receiving the filtering signal and reducing the voltage of the filtering signal to a preset signal for output; wherein, the step-down circuit includes: a first integrated device; a fourth diode, a forward end of which is grounded and a reverse end of which is connected to the source of the first integrated device; and the input end of the second inductor is connected with the source electrode of the first integrated device, and the output end of the second inductor is connected with the output end of the voltage transformation unit.)

1. A transformation unit based on a power transmission system, comprising:

the rectifying circuit is used for converting alternating current into direct current and outputting the direct current;

the filter circuit is connected with the rectifying circuit and is used for filtering the direct current to form a filter signal;

the voltage reduction circuit is used for receiving the filtering signal and reducing the voltage of the filtering signal to a preset signal for output; wherein the content of the first and second substances,

the step-down circuit includes:

a first integrated device;

a fourth diode, a forward end of which is grounded and a reverse end of which is connected to the source of the first integrated device;

and the input end of the second inductor is connected with the source electrode of the first integrated device, and the output end of the second inductor is connected with the output end of the voltage transformation unit.

2. The transformation unit based on the power transmission system according to claim 1, further comprising a feedback unit, specifically comprising:

one end of the first resistor is connected with the output end of the voltage transformation unit,

one end of the third resistor is connected with the output end of the voltage transformation unit, the other end of the third resistor is connected with the other end of the first resistor to form a feedback connecting end, and the feedback connecting end is connected with the feedback pin end of the first integrated device.

3. The transformation unit based on the power transmission system as claimed in claim 2, wherein the resistance of the first resistor is 5.6K Ω, and the resistance of the third resistor is 4.99K Ω.

4. The power transmission system-based transformation unit according to claim 1, wherein the filter circuit is formed by a first inductor, a fourth capacitor and a fifth capacitor, a positive terminal of the fourth capacitor is connected to one end of the first inductor, a negative terminal of the fourth capacitor is connected to a negative terminal of the fifth capacitor, and a positive terminal of the fifth capacitor is connected to the other end of the first inductor.

5. The power transmission system-based voltage transformation unit according to claim 4, wherein the capacitance value of the fourth capacitor is 2.2uf, and the capacitance value of the fifth capacitor is 4.7 uf.

6. The power transmission system-based voltage transformation unit according to claim 4, wherein the capacitance value of the fourth capacitor is 4.7uf, and the capacitance value of the fifth capacitor is 4.7 uf.

7. The transformation unit based on the power transmission system according to claim 4, further comprising a fifth resistor, wherein the fifth resistor is disposed between the negative terminal of the fourth capacitor and the negative terminal of the fifth capacitor.

8. The transformation unit based on the power transmission system according to claim 7, further comprising a sixth resistor, wherein one end of the sixth resistor is connected to the negative terminal of the fourth capacitor, and the other end of the sixth resistor is connected to the second type ground terminal.

9. The transformation unit based on the power transmission system of claim 1, further comprising an electrostatic protection circuit, wherein the electrostatic protection circuit is connected to the power input terminal.

Technical Field

The invention relates to the technical field of electric power measurement, in particular to a transformation unit based on a power transmission system.

Background

In the internet era, more and more electronic products tend to be more functional and intelligent, and a socket with on-off timing power consumption measurement becomes standard configuration of intelligent equipment. Generally, in the product design for realizing the above functions, the device for measuring the electric energy generally comprises a voltage reduction unit, most of the existing voltage reduction units adopt a transformer for reducing the voltage, but the volume of the transformer is relatively large, so that the following problems generally exist in the integration process: firstly, the volume or area of the circuit board or PCB is relatively large due to the volume of the transformer, especially, the layout of the circuit device is difficult to be compact, and the design of the product structure and appearance is inconvenient. In addition, the transformer is adopted for voltage reduction, the transformer in a working state and external noise are relatively large, the influence on voltage sampling and current sampling is large, the accuracy of sampling data is low, the voltage output based on the sampling data is usually in an unstable state, and the working precision of the metering device is reduced.

Disclosure of Invention

The invention aims to solve the defects in the prior art and provides a transformation unit for a power transmission system.

The invention provides a transformation unit based on a power transmission system, which comprises:

the rectifying circuit is used for converting alternating current into direct current and outputting the direct current;

the filter circuit is connected with the rectifying circuit and is used for filtering the direct current to form a filter signal;

the voltage reduction circuit is used for receiving the filtering signal and reducing the voltage of the filtering signal to a preset signal for output; wherein the content of the first and second substances,

the step-down circuit includes:

a first integrated device;

a fourth diode, a forward end of which is grounded and a reverse end of which is connected to the source of the first integrated device;

and the input end of the second inductor is connected with the source electrode of the first integrated device, and the output end of the second inductor is connected with the output end of the voltage transformation unit.

Preferably, the above voltage transformation unit based on the power transmission system further includes a feedback unit, and specifically includes:

one end of the first resistor is connected with the output end of the voltage transformation unit,

one end of the third resistor is connected with the output end of the voltage transformation unit, the other end of the third resistor is connected with the other end of the first resistor to form a feedback connecting end, and the feedback connecting end is connected with the feedback pin end of the first integrated device.

Preferably, in the transformation unit based on the power transmission system, a resistance value of the first resistor is 5.6K Ω, and a resistance value of the third resistor is 4.99K Ω.

Preferably, in the above voltage transformation unit based on the power transmission system, the filter circuit is formed by a first inductor, a fourth capacitor, and a fifth capacitor, a positive terminal of the fourth capacitor is connected to one end of the first inductor, a negative terminal of the fourth capacitor is connected to a negative terminal of the fifth capacitor, and a positive terminal of the fifth capacitor is connected to the other end of the first inductor.

Preferably, in the above voltage transformation unit based on the power transmission system, a capacitance value of the fourth capacitor is 2.2uf, and a capacitance value of the fifth capacitor is 4.7 uf.

Preferably, in the above voltage transformation unit based on the power transmission system, a capacitance value of the fourth capacitor is 4.7uf, and a capacitance value of the fifth capacitor is 4.7 uf.

Preferably, the above voltage transformation unit based on the power transmission system further includes a fifth resistor, and the fifth resistor is disposed between the negative terminal of the fourth capacitor and the negative terminal of the fifth capacitor.

Preferably, the above transformation unit based on the power transmission system further includes a sixth resistor, one end of the sixth resistor is connected to the negative terminal of the fourth capacitor, and the other end of the sixth resistor is connected to the second-type ground terminal.

Preferably, the above voltage transformation unit based on the power transmission system further includes an electrostatic protection circuit, and the electrostatic protection circuit is connected to the power input end.

Compared with the prior art, the invention has the advantages that:

in the invention, the linear non-isolated AD voltage reduction circuit is formed by the first integrated device, the first integrated device has smaller size, and simultaneously, the pins of the first integrated device are relatively fewer, and the peripheral circuit is simple. In addition, the current overload capacity of the first integrated device is strong, and the selection range of the internal resistance input into the first integrated device is wide. The PCB has larger layout space, the design of the power supply is greatly improved in size compared with the design of the isolated power supply, and convenience is brought to the reduction of the structural space.

Drawings

Fig. 1 is a circuit diagram of a transformation unit based on a power transmission system according to the present invention;

fig. 2 is a circuit diagram of a transformation unit based on a power transmission system according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

As shown in fig. 1, the present invention provides a transformation unit based on a power transmission system, wherein the transformation unit comprises:

the rectifying circuit is used for converting alternating current into direct current and outputting the direct current; further, the rectifier circuit is formed by a diode, the reverse end of the diode is connected with the electric energy input end, the forward end of the diode is connected with the filter circuit, and the diode is single-side rectification. The front end of the diode further comprises an overload protection device.

The filter circuit is connected with the rectifying circuit and is used for filtering the direct current to form a filter signal; further, the filter circuit is formed by a first inductor, a fourth capacitor and a fifth capacitor, wherein the positive terminal of the fourth capacitor is connected with one end of the first inductor, the negative terminal of the fourth capacitor is connected with the negative terminal of the fifth capacitor, and the positive terminal of the fifth capacitor is connected with the other end of the first inductor.

Further, in the above voltage transformation unit based on the power transmission system, a capacitance value of the fourth capacitor is 4.7uf, and a capacitance value of the fifth capacitor is 4.7 uf. Under the condition that the capacitance values of the fourth capacitor and the fifth capacitor are the same, a symmetrical circuit based on the first inductor is formed, wherein the resistance value of the first inductor is 1 mH.

When the fourth capacitor is a capacitor of 4.7uf, the volume of the capacitor is large, and based on this, further, the voltage transformation unit based on the power transmission system is described above, wherein a capacitance value of the fourth capacitor is 2.2uf, and a capacitance value of the fifth capacitor is 4.7 uf. A small volume capacitance of 2.2uf is used to facilitate circuit layout.

The voltage reduction circuit is used for receiving the filtering signal and reducing the voltage of the filtering signal to a preset signal for output; wherein the content of the first and second substances,

the voltage-reducing circuit comprises a voltage-reducing circuit,

a first integrated device; the first integrated device may be formed from a chip. The first integrated device current overload capability reaches 350 ma.

A fourth diode, a forward end of which is grounded and a reverse end of which is connected to the source of the first integrated device;

and the input end of the second inductor is connected with the source electrode of the first integrated device, and the output end of the second inductor is connected with the output end of the voltage transformation unit.

The working principle of the invention is that 220V voltage is input to a rectifying circuit through an overload protection device, the rectifying circuit converts 220V alternating current voltage information into 99V direct current signals for output, the direct current signals are filtered through a filter circuit to form direct current signals with stable voltage, the direct current signals are transmitted to a voltage reduction circuit, and elements inside the voltage reduction circuit, a fourth diode and a second inductor are combined with PWM waves formed inside a first integrated device to reduce the voltage of the direct current signals.

In the invention, the linear non-isolated AD voltage reduction circuit is formed by the first integrated device, the first integrated device has smaller size, and simultaneously, the pins of the first integrated device are relatively fewer, and the peripheral circuit is simple. In addition, the current overload capacity of the first integrated device is strong, and the selection range of the internal resistance input into the first integrated device is wide. The PCB has larger layout space, the design of the power supply is greatly improved in size compared with the design of the isolated power supply, and convenience is brought to the reduction of the structural space.

As a further preferred embodiment, the above voltage transformation unit based on a power transmission system further includes a feedback unit, specifically including:

one end of the first resistor is connected with the output end of the voltage transformation unit,

one end of the third resistor is connected with the output end of the voltage transformation unit, the other end of the third resistor is connected with the other end of the first resistor to form a feedback connecting end, and the feedback connecting end is connected with the feedback pin end of the first integrated device. And a third capacitor is connected between the feedback connection end and the source electrode, and the capacitance value of the third capacitor is 470 pf. In a simulation circuit, the third capacitor is not generally needed, but in actual use, the resistance of the first integrated device itself cannot be ignored, and in order to reduce the influence of the first integrated device itself on the circuit, the influence is eliminated by the third capacitor.

The resistance value of the first resistor is 5.6K omega, and the resistance value of the third resistor is 4.99K omega.

The capacitance value of the first capacitor is 220nf, one end of the first capacitor is connected with one end of the first resistor, the other end of the first capacitor is connected with one end of the third resistor, the first capacitor is connected with the first resistor and the third resistor in parallel to form an RC filter circuit, the value of the first capacitor is generally matched with the first resistor and the third resistor, and the first resistor and the third resistor are matched with the feedback connection end. The first capacitor is used for filtering the resistors at the two ends of the first resistor and the third resistor again so as to further filter the alternating current harmonic waves of the output voltage.

In use, the N terminal of the 220V voltage is connected to the ground terminal, which generates much noise. As a further preferred embodiment, the above-mentioned transformer unit based on a power transmission system further includes a fifth resistor, and the fifth resistor is disposed between the negative terminal of the fourth capacitor and the negative terminal of the fifth capacitor. The fifth resistor is a zero-ohm resistor, the electric energy stored in the fourth capacitor and the fifth capacitor can be rapidly released through the fifth resistor in the discharging process of the fourth capacitor and the fifth capacitor, and in addition, the N end is separated from the grounding end through the fifth resistor, so that the influence of noise on each functional circuit can be effectively reduced.

As shown in fig. 2, as a further preferred embodiment, the above-mentioned transformer unit based on a power transmission system further includes a sixth resistor, one end of the sixth resistor is connected to the negative terminal of the fourth capacitor, and the other end of the sixth resistor is connected to the second-type ground terminal. The N terminal is further isolated from the second-type ground terminal by a sixth resistor.

As a further preferred embodiment, the above-mentioned voltage transformation unit based on a power transmission system further includes an electrostatic protection circuit, and the electrostatic protection circuit is connected to the power input terminal.

The electrostatic protection circuit comprises an L-end electrostatic protection branch circuit and an N-end electrostatic protection branch circuit, wherein the L-end electrostatic protection branch circuit is formed by connecting a pair of diodes, one diode is connected between the L output end and the ground in parallel in the forward direction, the other diode is connected between the L output end and the ground in parallel in the reverse direction, four 510K omega resistors are arranged between the L output end and the diodes, and the four 510K omega resistors are used for carrying out voltage division processing on L voltage. When the static electricity of KV is input from the input end, the diode is broken down in the reverse direction, and meanwhile, the charges are discharged to the ground or the power supply rapidly. The positive static electricity is mostly discharged to the power source, and the negative static electricity is mostly discharged to the ground. The purposes of reducing signal noise and protecting the circuit are achieved.

Similarly, the N-terminal electrostatic protection branch at least includes an N-terminal electrostatic protection input branch and an N-terminal electrostatic protection output branch, and the N-terminal electrostatic protection input/output branch is formed by connecting a pair of diodes.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.