A DC grid bidirectional current blocking circuit based on series switches
A DC power grid and blocking circuit technology, applied in the direction of emergency protection circuit devices, electrical components, etc., can solve the problems that cannot fully meet the needs of quickly blocking two-way short-circuit current, and achieve modularization, reduced response time, and simple control Effect
Active Publication Date: 2021-03-02
HUBEI UNIV OF TECH
View PDF6 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
In order to overcome these shortcomings, a variety of new power electronic devices are applied to this occasion. However, the existing DC short-circuit fault current limiter can only limit the short-circuit current and needs to be used with a circuit breaker, which cannot fully meet the needs of rapid detection of power grid faults. The need to block bidirectional short-circuit current
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment
[0069] by Figure 9 In order to implement the scene, the circuit of the present invention plays a protective role in the power grid and solar power station. It can not only protect the grid to transmit electric energy to the solar power station, but also protect the solar energy to transmit grid-connected electric energy to the grid. In this embodiment, the power transmission of 600V DC voltage after AC-DC conversion through the power grid is taken as an example. During the normal operation period of the line, the power transmission is performed by the main switch. Assuming that a short-circuit fault occurs at 0.2s, the current at the main port of the blocking circuit rises linearly at a certain rate. When the short-circuit current exceeds the set threshold, the detection signal triggers the thyristor Q1 to conduct, and the capacitor starts to charge. At the same time, the line current decays to zero, and the blocking time is only 2-3ms. After that, the thyristor is naturally...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention relates to a DC grid bidirectional current blocking circuit based on series switches. The circuit includes two switch tubes S1 and S2, two diodes D1 and D2, two thyristors Q1 and Q2, a bidirectional thyristor Q3, a capacitor C, a resistor R, and a varistor MOV. The circuit of the present invention is connected in series in the DC power grid. When no short-circuit fault occurs, the switch tube S1 is turned on and the switch tube S2 is turned on to turn on the current from P1 to P2; the switch tube S2 is turned on and the switch tube S1 is turned off to When the current from P2 to P1 is turned on, the switch tubes S1 and S2 basically do not produce a voltage drop; when a short-circuit fault occurs, by controlling the switch off of the switch tube S1 or S2, the capacitor from P1 to P2 or P2 to P1 can be blocked quickly. short-circuit current. Compared with the previous power electronic fault current limiter, the circuit of the present invention not only has low cost, but also has simple control, fast response speed, can completely block bidirectional short-circuit current, and can be used as a circuit breaker.
Description
technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a DC grid bidirectional current blocking circuit based on a series switch. Background technique [0002] With the continuous development of DC transmission technology and high-power power electronic devices, DC transmission projects are increasing day by day. However, the impedance of DC lines is low. When a short-circuit fault occurs, the circuit current increases rapidly and reaches the level that the grid cannot bear in a short period of time. At this point, DC circuit breakers, as the key equipment of DC transmission, can quickly isolate faults, and are increasingly concerned by people. [0003] The grid-connected structure in the power grid needs to be applied to DC circuit breakers. Here, traditional fuses and circuit breakers are used to block the short-circuit current. If the fuse is blown, it needs to be replaced. The circuit breaker cannot act in ...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): H02H7/26
CPCH02H7/268
Inventor 王鹿军冯博宇王钰吴铁洲周传建李拥军
Owner HUBEI UNIV OF TECH