Power distribution cabinet capable of eliminating surge current

Abstract

The invention relates to the technical field of power distribution, in particular to a power distribution cabinet capable of eliminating surge current, which comprises a power line, the power line is connected with a plurality of load lines, each phase of the power line is provided with an anti-surge module, and each anti-surge module comprises a PTC (Positive Temperature Coefficient) thermistor, an NTC (Negative Temperature Coefficient) thermistor, a first switch and a second switch, the PTC type thermistor and the first switch are connected in series to form a PTC type thermistor assembly, the NTC type thermistor and the second switch are connected in series to form an NTC type thermistor assembly, and the PTC type thermistor assembly and the NTC type thermistor assembly are connected in parallel. According to the invention, the NTC type thermistor is arranged, so that the resistance value is changed from high to low and the current is changed from small to large after the NTC type thermistor is heated when the electric wire is switched on, and the PTC type thermistor is arranged, so that the resistance value is changed from low to high and the current is changed from large to small after the PTC type thermistor is heated when the electric wire is switched off, and accidents such as fire are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of power distribution, and in particular to a power distribution cabinet capable of eliminating surge current. Background Art

[0002] In the power grid, many loads are motors. These loads have many coils. When a load with a coil is connected or disconnected in the power grid, the coil will generate high voltage due to the sudden change in current. This high voltage can cause other loads to overload or be damaged, such as fire. Some electric bicycles caught fire while charging, and the surge current generated caused the electric bicycle next to it to catch fire. Therefore, eliminating surge current in the power grid has become an important way to prevent fires. Summary of the invention

[0003] In order to solve the problems in the above-mentioned background technology, the present invention provides a distribution cabinet capable of eliminating surge current, which is used in the distribution cabinet and solves the problem of surge current damaging the load when the circuit is disconnected or connected in the prior art.

[0004] The solution adopted by the present invention to solve its technical problem is: a distribution cabinet capable of eliminating surge current, comprising a power line, the power line being connected to a plurality of load lines, the plurality of load lines being connected in parallel, wherein each phase of the load line is provided with an anti-surge module capable of eliminating surge current.

[0005] In the above structure, the surge protection module includes a PTC thermistor, an NTC thermistor, a first switch, and a second switch. The PTC thermistor is connected in series with the first switch to form a PTC thermistor assembly. The NTC thermistor is connected in series with the second switch to form an NTC thermistor assembly. The PTC thermistor assembly in which the PTC thermistor is connected in series with the first switch is connected in parallel with the NTC thermistor assembly in which the NTC thermistor is connected in series with the second switch.

[0006] The above structure also includes a third switch, which is connected in parallel with the PTC thermistor component and the NTC thermistor component.

[0007] The above structure also includes a fourth switch. The third switch, the PTC thermistor assembly, and the NTC thermistor assembly are connected in parallel to form a dual resistor assembly. The fourth switch is connected in series with the dual resistor assembly.

[0008] In the above structure, the third switch is set to be closed after the first switch is closed, and the third switch is set to be opened after the second switch is opened. The first switch and the second switch are both normally open switches, and the time for the first switch and the second switch to be in the closed state is 3 seconds to 10 seconds.

[0009] In summary, the beneficial effects of the present invention are as follows: by setting an NTC thermistor, when the wire is connected, the resistance value of the NTC thermistor changes from high to low after being heated, and the current also changes from small to large to prevent current mutation; by setting a PTC thermistor, when the wire is disconnected, the resistance value of the PTC thermistor changes from low to low high after being heated, and the current also changes from large to small to prevent current mutation, so that the current changes slowly when the load is disconnected or connected, reducing the damage to the power supply and the load caused by the surge formed by the current mutation, reducing the occurrence of accidents such as fire, or reducing the damage to the load.

[0010] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural diagram of the surge protection module of the present invention.

[0012] In the figure: 1. PTC thermistor; 2. NTC thermistor; 3. first switch; 4. second switch; 5. third switch; 6. fourth switch. DETAILED DESCRIPTION

[0013] In order to make the content of the present invention more clearly understood, the present invention is further described below based on specific embodiments in conjunction with the accompanying drawings.

[0014] It should be noted that the terms "center", "upper", "lower", "front", "back", "left", "right", "inner", "outer" and the like used herein to indicate directions or positional relationships are based on directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. Unless otherwise specified, "plurality" means two or more.

[0015] Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0016] Referring to the accompanying drawings, a power distribution cabinet capable of eliminating surge current includes a power line connected to a plurality of load lines connected in parallel, wherein each phase of the load line is provided with an anti-surge module capable of eliminating surge current.

[0017] Furthermore, the surge protection module includes a PTC thermistor 1, an NTC thermistor 2, a first switch 3, and a second switch 4. The PTC thermistor 1 is connected in series with the first switch 3 to form a PTC thermistor assembly, and the NTC thermistor 2 is connected in series with the second switch 4 to form an NTC thermistor assembly. The PTC thermistor assembly formed by the PTC thermistor 1 and the first switch 3 being connected in series is connected in parallel with the NTC thermistor assembly formed by the NTC thermistor 2 and the second switch 4 being connected in series. The PTC thermistor is a typical semiconductor resistor with temperature sensitivity. When a certain temperature (Curie temperature) is exceeded, its resistance value increases stepwise with the increase of temperature. The resistance value of the NTC thermistor 2 decreases with the increase of temperature.

[0018] Furthermore, the device further comprises a third switch 5, which is connected in parallel with the PTC thermistor assembly and the NTC thermistor assembly. The third switch 5 can be turned on when the current is in a normal state, thereby reducing the resistance value in the circuit and reducing energy consumption.

[0019] Further, the third switch 5 is set to be closed after the first switch 3 is closed, and the third switch 5 is set to be opened after the second switch 4 is opened. The first switch 3 and the second switch 4 are both normally open switches, and the time for the first switch 3 and the second switch 4 to be in the closed state is 3 seconds to 10 seconds. The third switch 5 is a normally closed switch.

[0020] Furthermore, it also includes a fourth switch 6, the third switch 5, the PTC thermistor assembly, and the NTC thermistor assembly are connected in parallel to form a dual resistor assembly, and the fourth switch 6 is connected in series with the dual resistor assembly. The fourth switch 6 can disconnect the circuit when the load is disconnected to ensure that the voltage of the load line is zero.

[0021] When the second switch 4 in the circuit is closed and the first switch 3 is opened and the circuit is connected, the resistance of the NTC thermistor 2 is relatively large, so the NTC thermistor 2 will heat up when current passes through it. Since the NTC thermistor 2 will heat up, the resistance of the NTC thermistor 2 will decrease, so that the current in the circuit will gradually increase, and the PTC thermistor 1 will not work.

[0022] When the second switch 4 in the circuit is disconnected and the first switch is closed, the resistance of the PTC thermistor 1 is small, so when current passes through it, the PTC thermistor 1 will also heat up. Since the PTC thermistor 1 will heat up, the resistance of the PTC thermistor 1 will increase, so the current in the circuit will also gradually decrease, and the NTC thermistor 2 will not work. The surge current when the circuit is disconnected is eliminated by the PTC thermistor 1, and the surge current when the circuit is connected is eliminated by the NTC thermistor 2, so that the circuit surge current can be eliminated.

[0023] When the PTC thermistor 1 makes the current in the circuit from the normal load state to very small or the NTC thermistor 2 makes the current change from zero to a large value to the normal state, the third switch 5 can be closed to allow the current to flow through the third switch 5. In this way, power consumption can be reduced. The PTC thermistor 1 and the NTC thermistor 2 will also generate energy consumption in the circuit.

[0024] The present invention sets an NTC thermistor 2 so that when the electric wire is connected, the resistance value of the NTC thermistor 2 changes from high to low after being heated, and the current also changes from small to large to prevent the current mutation. The present invention sets a PTC thermistor 1 so that when the electric wire is disconnected, the resistance value of the PTC thermistor 1 changes from low to low high after being heated, and the current also changes from large to small to prevent the current mutation. In this way, the current changes slowly when the load is disconnected or connected, and the damage to the power supply and the load caused by the surge formed by the current mutation is reduced, and the occurrence of accidents such as fire is reduced.

[0025] The embodiments described above are only preferred implementation modes of the present invention and cannot be used to limit the protection scope of the present invention. Any non-substantial changes and modifications made by those skilled in the art on the basis of the invention shall fall within the protection scope of the present invention.

Claims

1. A power distribution cabinet capable of eliminating surge current, characterized in that: It comprises a power line, which is connected to a plurality of load lines, and the plurality of load lines are connected in parallel, wherein each phase of the load lines is provided with an anti-surge module capable of eliminating surge current.

2. The power distribution cabinet according to claim 1, characterized in that: The anti-surge module includes a PTC thermistor, an NTC thermistor, a first switch, and a second switch. The PTC thermistor is connected in series with the first switch to form a PTC thermistor assembly. The NTC thermistor is connected in series with the second switch to form an NTC thermistor assembly. The PTC thermistor assembly formed by connecting the PTC thermistor in series with the first switch and the NTC thermistor assembly formed by connecting the NTC thermistor in series with the second switch are connected in parallel.

3. The power distribution cabinet according to claim 2, characterized in that: It also includes a third switch, which is connected in parallel with the PTC thermistor component and the NTC thermistor component.

4. The power distribution cabinet according to claim 3, characterized in that: It also includes a fourth switch, the third switch, the PTC thermistor component, and the NTC thermistor component are connected in parallel to form a dual resistor component, and the fourth switch is connected in series with the dual resistor component.

5. The power distribution cabinet according to claim 3, characterized in that: The third switch is configured to be closed after the first switch is closed, and the third switch is configured to be opened after the second switch is opened. The first switch and the second switch are both normally open switches, and the time for which the first switch and the second switch are in the closed state is 3 seconds to 10 seconds.

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