Alternating current anti-reflux method

Abstract

The invention relates to the technical field of alternating current grid-connected operation countercurrent prevention, in particular to an alternating current countercurrent prevention method which has the advantages that the structure is simple, and countercurrent can be completely prevented; comprising alternating current positive and negative half-cycle phase sampling driving control, a power switch tube and an ideal diode or a universal diode. An alternating current input is connected to the alternating current positive and negative half-cycle phase sampling driving control part for sampling and is connected to the power switch tubes for providing power input, and the alternating current positive and negative half-cycle phase sampling driving control part outputs two paths of signals to respectively drive and control the corresponding power switch tubes. The output of the switching tube passes through the ideal diode or the universal diode and then outputs respective positive half-cycle and negative half-cycle alternating current in parallel.

Description

Technical Field

[0001] The present invention relates to the technical field of preventing reverse current in the grid connection operation of alternating current, and particularly to an alternating current reverse current prevention method. Background Art

[0002] With the popularization of new energy power generation and self-use energy storage devices, in order to make up for the insufficient self-generated power from the power grid when needed, it is necessary to connect to the grid for power generation and have a complete reverse current prevention function to achieve the functions of grid-connected operation for power consumption and off-grid operation for power generation. Currently, the mainstream method is to use dynamic adjustment of the power of the self-generated power equipment to achieve reverse current prevention. This reverse current prevention technology has a drawback that when the user load suddenly shuts down, the self-generated power equipment requires an automatic power control process of several milliseconds to reduce the power generation, and a surge reverse current will be generated during this process and flow back to the power grid.

[0003] To solve the above problems, the present invention proposes an alternating current reverse current prevention method, which can achieve complete alternating current reverse current prevention and has the advantages of simple structure and easy implementation. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides an alternating current reverse current prevention method with a simple structure and complete reverse current prevention.

[0005] The alternating current reverse current prevention method of the present invention includes alternating current positive and negative half-cycle phase sampling drive control, power switching tubes, ideal diodes or general diodes;

[0006] The alternating current input is connected to the alternating current positive and negative half-cycle phase sampling drive control part for sampling, and at the same time is connected to the power switching tubes to provide power input. The alternating current positive and negative half-cycle phase sampling drive control part outputs two signals to respectively drive and control the corresponding power switching tubes. The outputs of the switching tubes are connected in parallel after passing through the ideal diodes or general diodes to output the positive and negative half-cycle alternating currents respectively.

[0007] In the alternating current reverse current prevention method of the present invention, the working steps of the alternating current positive and negative half-cycle phase sampling drive control include: sampling the input alternating current, separating the positive and negative half-cycles, generating two drive signals for the positive and negative half-cycles. The logic of the two signals is: one is that the corresponding drive power switching tube is turned on during the positive half-cycle and turned off during the negative half-cycle, and the other is that the corresponding drive power switching tube is turned on during the negative half-cycle and turned off during the positive half-cycle.

[0008] In the alternating current reverse current prevention method of the present invention, the power switching tubes include: field effect transistors and related MOS tubes, IGBTs, triodes, thyristors.

[0009] In the alternating current reverse current prevention method of the present invention, the ideal diodes or general diodes include: circuits constructed by circuits with diode functions, general diodes, Schottky diodes.

[0010] The AC anti-counterflow method of the present invention utilizes three sets of the above AC anti-counterflow method structures and is applied to three-phase alternating current to achieve anti-counterflow of three-phase alternating current.

[0011] The beneficial effects of the present invention are: simple structure and complete anti-counterflow can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 AC anti-counterflow block diagram system;

[0013] Figure 2 Topological structure of three-phase alternating current constructed by the AC anti-counterflow system. DETAILED DESCRIPTION OF THE INVENTION

[0014] The following combines the drawings and embodiments to further describe in detail the specific implementation manners of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0015] As Figure 1 and Figure 2 shown, the AC anti-counterflow method of the present invention includes AC positive and negative half-cycle phase sampling drive control, power switching tubes, ideal diodes or general diodes;

[0016] The AC input is connected to the AC positive and negative half-cycle phase sampling drive control part for sampling, and at the same time is connected to the power switching tubes to provide power input. The AC positive and negative half-cycle phase sampling drive control part outputs two signals to respectively drive and control the corresponding power switching tubes. The outputs of the switching tubes are connected in parallel after passing through ideal diodes or general diodes to output the positive and negative half-cycle alternating currents respectively.

[0017] For the AC anti-counterflow method of the present invention, the working steps of the AC positive and negative half-cycle phase sampling drive control include: sampling the input AC, separating the positive and negative half-cycles, generating two drive signals for the positive and negative half-cycles. The logic of the two signals is: one is that the corresponding drive power switching tube is turned on during the positive half-cycle and turned off during the negative half-cycle, and the other is that the corresponding drive power switching tube is turned on during the negative half-cycle and turned off during the positive half-cycle.

[0018] For the AC anti-counterflow method of the present invention, the power switching tubes include: field effect tubes and related MOS tubes, IGBTs, triodes, thyristors.

[0019] For the AC anti-counterflow method of the present invention, the ideal diodes or general diodes include: circuits with diode functions constructed by circuits, general diodes, Schottky diodes.

[0020] The AC anti-counterflow method of the present invention utilizes three sets of the above AC anti-counterflow method structures and is applied to three-phase alternating current to achieve anti-counterflow of three-phase alternating current.

[0021] When there is grid-connected power generation equipment connected to the AC output terminal, if synchronization with the input AC power is generated and the voltage of this AC power is higher than the input voltage.

[0022] In the first case when working in the positive half cycle, the corresponding positive half cycle diode has unidirectional conductivity, preventing the positive half cycle voltage at the output terminal from flowing into the power switch tube. The negative half cycle diode conducts through this positive half cycle voltage and flows into the power switch tube. Also, since it is working in the positive half cycle at this time, the switch tube in this negative cycle is in the off state, blocking the flow of the high voltage in the positive half cycle to the input terminal.

[0023] In the second case when working in the negative half cycle, it is the same as above.

[0024] The above realizes the prevention of reverse flow of alternating current.

[0025] The method for preventing reverse flow of alternating current, its topology structure and control process include the combination in the appendix Figure 2 to realize the prevention of reverse flow in the case of three-phase alternating current.

[0026] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An AC anti-counterflow method, characterized in that, It includes the phase sampling drive control for the positive and negative half-cycles of alternating current, power switching tubes, ideal diodes or general diodes; The alternating current input is connected to the phase sampling drive control section for the positive and negative half-cycles of alternating current for sampling, and at the same time is connected to the power switching tubes to provide power input. The phase sampling drive control section for the positive and negative half-cycles of alternating current outputs two signals to respectively drive and control the corresponding power switching tubes. After the outputs of the switching tubes pass through the ideal diodes or general diodes, the positive and negative half-cycles of alternating current are output in parallel respectively.

2. The AC anti-counterflow method according to claim 1, wherein The working steps of the phase sampling drive control for the positive and negative half-cycles of alternating current include: sampling the input alternating current, separating the positive and negative half-cycles, generating two drive signals for the positive and negative half-cycles. The logic of the two signals is: one is that the corresponding drive power switching tube is turned on during the positive half-cycle and turned off during the negative half-cycle, and the other is that the corresponding drive power switching tube is turned on during the negative half-cycle and turned off during the positive half-cycle.

3. The AC anti-counterflow method according to claim 1, wherein, The power switching tubes include: field effect transistors and related MOS tubes, IGBTs, triodes, thyristors.

4. The AC anti-counterflow method according to claim 1, wherein The ideal diodes or general diodes include: circuits with diode functions constructed by circuits, general diodes, Schottky diodes.

5. The AC anti-counterflow method according to claim 1, characterized in that, It includes using three sets of the above AC anti-counterflow method structures and applying them to three-phase alternating current to achieve anti-counterflow of three-phase alternating current.

Images