A high-voltage alternating electric field energy harvesting system based on switched capacitor mode

Abstract

The application discloses a high-voltage alternating electric field energy-taking system based on a switched capacitor mode, wherein a high-voltage conductor is connected with a first input end of a high-voltage rectifying unit; a positive output end of the high-voltage rectifying unit is connected with one end of an energy storage capacitor, one end of a starting resistor, a negative electrode of a freewheeling diode and one end of a main winding in a pre-stage inductor; the other end of the main winding in the pre-stage inductor is connected with one end of a switching transistor, a positive electrode of a first diode and a negative electrode of a second diode; the positive electrode of the second diode is connected with one end of an output capacitor; the other end of the output capacitor and the negative electrode of the first diode are connected with a series-parallel capacitor branch; the same-named end of a driving winding in the pre-stage inductor is connected with a driving end of the switching transistor through a driving capacitor and a driving resistor; the other end of the starting resistor is connected with the driving end of the switching transistor; and the system has high reliability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of online monitoring of power system, and relates to a high-voltage alternating electric field energy extraction system based on switched capacitor mode. BACKGROUND

[0002] With the development of online monitoring technology of smart grid, when the high potential end equipment in the power system needs to be monitored, how to solve the power supply problem of the front-end monitoring equipment becomes a technical difficulty. The high-voltage transmission line alternating electric field and the distributed capacitance to the ground are used to directly charge the energy extraction capacitor. Due to the low power conversion efficiency, the power provided by the power supply cannot meet the real-time collection and transmission tasks of the relevant monitoring signals. If the energy extraction capacitor and its control unit are directly connected in series to improve the energy extraction power, the volume and power consumption of the control system will be increased, and the reliability of the power supply system will be reduced due to the increase of system complexity. SUMMARY

[0003] The present application aims to overcome the shortcomings of the prior art and provides a high-voltage alternating electric field energy extraction system based on switched capacitor mode, which has high reliability.

[0004] To achieve the above-mentioned purpose, the high-voltage alternating electric field energy extraction system based on switched capacitor mode comprises a high-voltage conductor, a high-voltage rectifier unit, an energy storage capacitor, a freewheeling diode, a starting resistor, a front-stage inductor, a switching transistor, a first diode, a second diode, an output capacitor, a driving capacitor, a driving resistor and a series-parallel capacitor branch.

[0005] The high-voltage conductor is connected with the first input end of the high-voltage rectifier unit. The positive output end of the high-voltage rectifier unit is connected with one end of the energy storage capacitor, one end of the starting resistor, the negative electrode of the freewheeling diode and one end of the main winding of the front-stage inductor. The other end of the main winding of the front-stage inductor is connected with one end of the switching transistor, the positive electrode of the first diode and the negative electrode of the second diode. The positive electrode of the second diode is connected with one end of the output capacitor. The other end of the output capacitor and the negative electrode of the first diode are connected with the series-parallel capacitor branch. The same end of the driving winding of the front-stage inductor is connected with the driving end of the switching transistor through the driving capacitor and the driving resistor. The other end of the starting resistor is connected with the driving end of the switching transistor. The other end of the energy storage capacitor, the positive electrode of the freewheeling diode, the other end of the switching transistor and the non-same end of the driving winding of the front-stage inductor are all grounded.

[0006] The high-voltage rectifier unit comprises a rectifier bridge and a capacitor.

[0007] The high-voltage conductor is connected with the first input end of the rectifier bridge. The second input end of the rectifier bridge is connected with the ground through the ground distribution capacitor. The positive output end of the rectifier bridge is connected with the energy storage capacitor, the starting resistor, the freewheeling diode and the main winding of the front-stage inductor.

[0008] The front-stage inductor comprises a magnetic core and a main winding and a driving winding wound on the magnetic core.

[0009] The present application has the following advantages:

[0010] The high-voltage alternating electric field energy-taking system based on the switched capacitor mode has the advantages that the switching transistor does not need to bear the flyback voltage, so the maximum input voltage allowed by the power supply can be greatly improved, thereby improving the input power. In the switched capacitor mode, voltage conversion is realized through the conversion of the circuit topology, and a transformer is not involved, so the loss can be reduced and the power supply efficiency can be improved. It should be noted that the control and adjustment of the power supply are in a self-excitation mode, and complex control circuits and components are not needed, so the design of the power supply system is simplified, and the reliability of the power supply system is improved. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 The present application has the following advantages: DETAILED DESCRIPTION

[0012] In order for those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments, and are not intended to limit the scope of the present application. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed in the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the scope of the present application.

[0013] The structural schematic diagram according to the disclosed embodiments of the present application is shown in the drawings. These drawings are not drawn to scale, in which certain details are exaggerated for the purpose of clear expression, and certain details can be omitted. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are only exemplary, and in actuality, there can be deviations due to manufacturing tolerances or technical limitations, and regions / layers with different shapes, sizes and relative positions can be additionally designed by those skilled in the art according to actual needs.

[0014] Reference Figure 1 The high-voltage alternating electric field energy-taking system based on the switched capacitor mode comprises a high-voltage conductor, a rectifier bridge B, a capacitor Cg, an energy storage capacitor Cin, a freewheeling diode D1, a starting resistor Rs, a front-stage inductor L, a switching transistor Q, a first diode D2, a second diode D3, an output capacitor Co, a driving capacitor Cb, a driving resistor Rb and a series-parallel capacitor branch.

[0015] The high-voltage conductor is connected with the first input end of the rectifier bridge B, the second input end of the rectifier bridge B is connected with the ground through the capacitor Cg, the positive output end of the rectifier bridge B is connected with one end of the energy storage capacitor Cin, one end of the starting resistor Rs, the negative electrode of the freewheeling diode D1 and one end of the main winding of the pre-stage inductor L, the other end of the main winding of the pre-stage inductor L is connected with one end of the switching transistor Q, the positive electrode of the first diode D2 and the negative electrode of the second diode D3, the positive electrode of the second diode D3 is connected with one end of the output capacitor Co, the other end of the output capacitor Co and the negative electrode of the first diode D2 are connected with the series-parallel capacitor branch, the same end of the driving winding of the pre-stage inductor L is connected with the driving end of the switching transistor Q through the driving capacitor Cb and the driving resistor Rb, the other end of the starting resistor Rs is connected with the driving end of the switching transistor Q, the other end of the energy storage capacitor Cin, the positive electrode of the freewheeling diode D1, the other end of the switching transistor Q and the non-same end of the driving winding of the pre-stage inductor L are all connected with the ground.

[0016] The series-parallel capacitor branch is composed of n capacitors and 2n-2 parallel branch diodes, and the connection mode of the parallel mode is that: except the first and the n parallel branches, the second to the n-1 parallel branches are all composed of one capacitor and two diodes in series; the two diodes are respectively located at the upper and lower ends of the branch capacitor, the positive electrode of the upper end diode is connected with the high-voltage end of the branch capacitor, and the negative electrode of the upper end diode is connected with the parallel high-voltage end H of the circuit; the negative electrode of the lower end diode of the branch capacitor is connected with the low-voltage end of each branch capacitor, and the positive electrode is connected with the power supply ground.

[0017] For the first and the n parallel branches, they are all composed of one capacitor and one parallel branch diode in series; the high-voltage end of the capacitor of the first parallel branch is connected with H, the low-voltage end of the capacitor is connected with the negative electrode of the diode, and the positive electrode of the diode is connected with the power supply ground; the high-voltage end of the capacitor of the n parallel branch is connected with the positive electrode of the diode, the negative electrode of the diode is connected with H, and the low-voltage end of the branch capacitor is connected with the power supply ground.

[0018] The series connection mode of the series-parallel branch is that: on the basis of the connection mode of the parallel mode, n-1 series diodes are added, and according to the order from the first to the n branch, the low-voltage end of the capacitor of the previous branch is connected with the positive electrode of the series diode, the K level of the series diode is connected with the high-voltage end of the capacitor of the next branch; the collector of the switching transistor Q is connected with the positive electrode of the high-voltage diode, and the negative electrode of the diode is connected with the H point of the series-parallel branch.

[0019] The specific working process of the application is as follows:

[0020] The high-voltage conductor charges the energy storage capacitor Cin through the rectifier bridge B, and the input power of the energy source is increased by adding the capacitor Cg, and in actual application, the area of the ground electrode connected with the second input end of the rectifier bridge B can be appropriately increased.

[0021] The capacitors of the series-parallel capacitor branch are connected in series through diodes and in parallel through a discharge circuit. Taking 3 series and 3 parallel capacitors as an example, as shown in Figure 1 , the series charging path is ch1 and the parallel discharge path is ch2.

[0022] The power supply startup process is as follows: in the initial state, the switch transistor Q is off, and the high-voltage conductor charges the energy storage capacitor Cin through the rectifier bridge B. When the voltage of the energy storage capacitor Cin reaches the startup threshold, a current is injected to the drive end of the switch transistor Q through the startup resistor Rs, causing the switch transistor Q to turn on. At this time, according to Figure 1 , a positive voltage is generated in the drive winding, which is a positive feedback voltage. The positive voltage is loaded on the drive end of the switch transistor Q through the drive resistor Rb and the drive capacitor Cb, causing the switch transistor Q to further saturate and turn on.

[0023] In the above process, the current in the main winding of the front-stage inductor L gradually increases and reaches a maximum to complete the energy storage of the inductor. On the other hand, due to the turn-on of the switch transistor Q, the potential of point A in the circuit is pulled down to the power supply ground, causing the parallel discharge of the rear-stage circuit to start, as shown in Figure 1 , the discharge process charges the output capacitor Co. In the present application, the parallel discharge voltage is 1 / 3 of the charging voltage.

[0024] When the drive current starts to decrease after passing the peak value, the current in the main winding of the front-stage inductor L decreases, and a reverse voltage is generated in the drive winding, which causes the drive current of the switch transistor Q to quickly return to zero, and the switch transistor Q quickly turns off. When the switch transistor Q turns off, the polarity of the front-stage inductor L reverses, and the potential of point A in the circuit returns to high, so the first diode D2 turns off, and the parallel discharge process through the ch2 circuit ends, and the energy stored in the front-stage inductor L charges the series-parallel branch in series through the freewheeling diode D1 and the first diode D2, as shown in Figure 1 .

[0025] With the release of electrical energy and the rise of the rear-stage series charging voltage, the series charging current gradually decreases to zero, preparing for the next startup of the power supply.

Claims

1. A switched-capacitor-mode-based high-voltage alternating electric field power harvesting system, characterized by, The high-voltage conductor, a high-voltage rectifying unit, an energy storage capacitor (Cin), a freewheeling diode (D1), a starting resistor (Rs), a front-stage inductor (L), a switching transistor (Q), a first diode (D2), a second diode (D3), an output capacitor (Co), a driving capacitor (Cb), a driving resistor (Rb), and a series-parallel capacitor branch; The high-voltage conductor is connected with a first input end of the high-voltage rectifying unit, a positive output end of the high-voltage rectifying unit is connected with one end of the energy storage capacitor (Cin), one end of the starting resistor (Rs), a negative electrode of the freewheeling diode (D1), and one end of a main winding of the front-stage inductor (L), the other end of the main winding of the front-stage inductor (L) is connected with one end of the switching transistor (Q), a positive electrode of the first diode (D2), and a negative electrode of the second diode (D3), the positive electrode of the second diode (D3) is connected with one end of the output capacitor (Co), the other end of the output capacitor (Co) and the negative electrode of the first diode (D2) are connected with the series-parallel capacitor branch, the same-named end of a driving winding of the front-stage inductor (L) is connected with the driving end of the switching transistor (Q) through the driving capacitor (Cb) and the driving resistor (Rb), the other end of the starting resistor (Rs) is connected with the driving end of the switching transistor (Q), the other end of the energy storage capacitor (Cin), the positive electrode of the freewheeling diode (D1), the other end of the switching transistor (Q), and the non-same-named end of the driving winding of the front-stage inductor (L) are grounded. The series-parallel capacitor branch is composed of n capacitors and 2n-2 parallel branch diodes, and further includes n-1 series diodes, the capacitors of the series-parallel capacitor branch are connected through diodes to form a series charging circuit and a parallel discharging circuit.

2. The switched-capacitor-based high-voltage AC electric field power harvesting system of claim 1, wherein, The high-voltage rectifying unit includes a rectifying bridge (B) and a capacitor (Cg). The high-voltage conductor is connected with a first input end of the rectifying bridge (B), a second input end of the rectifying bridge (B) is connected with the ground through a ground distribution capacitor (Cg), and a positive output end of the rectifying bridge (B) is connected with the energy storage capacitor (Cin), the starting resistor (Rs), the freewheeling diode (D1), and the main winding of the front-stage inductor (L).

3. The switched-capacitor-based high-voltage AC electric field power harvesting system of claim 1, wherein, The front-stage inductor (L) includes a magnetic core and a main winding and a driving winding wound on the magnetic core.

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