CN100517543C - Self-generated power supply for power circuit breaker - Google Patents

Abstract

The invention provides a kind of autogeny power for a control device. The power can be constructed under to small inductive current, thus the range of the breaker can be enlarged, thus it can work normally even with current which is 50%, even 16% of the normal current. The power includes several current mutual-inductors, switch power, energy-saving capacitance, there adds a first-grade resistance converter between the input end of the switch power and the energy-saving capacitance, it reduces the output resistance of the current mutual-conductor, and thus the inductive current can be outputted fully. The output resistance of the converter is high; it can supply power to the switch and the energy-saving capacitance.

Description

Self-generated power supply for power circuit breaker

technical field

The invention belongs to the field of electrical appliances, and relates to an electronic detection control device for tripping of a power circuit breaker, in particular to a self-generated power supply of the control device.

Background technique

In the electronic release of the power circuit breaker, also known as the electronic controller, the power cannot be obtained directly from the relevant power grid, so as not to provide normal power for the controller when these power grids fail, which will cause the controller to fail. For this reason, the controller needs to self-generate and de-induce energy from the fault overcurrent to establish a power supply for itself, which is called self-generated power supply. At the same time, in normal operation, it is also necessary to sense the self-generated power directly from the load of the circuit breaker, that is, the mains current. Because the current intensity at this time is too small, the working range of the circuit breaker is limited, such as the circuit breakers of large companies in the world. The setting current range is between 50% and 100% of the rated current.

The general structure of the self-generated power supply of the electronic controller is that the current transformer induces the current from the main line current, and enters the general switching power supply mode to work. After charging an energy storage capacitor, the power supply voltage is established. component power.

When the mains current is small, the induction current of the current transformer is too small to supply power for the switching power supply and the energy storage capacitor. At this time, there is energy, but the input and output impedances of the two do not match, so it is difficult to establish a self-generated power supply. .

Contents of the invention

The purpose of the present invention is to provide a self-generated power supply that can be established even under a small induced current, thereby expanding the setting range of the circuit breaker so that it can work normally under 50% or even 16% of the rated current value.

The scheme design of the present invention is: a self-generated power supply for a power circuit breaker, including several current transformers, switching power supplies, and energy storage capacitors. A first-stage impedance converter is added between the capacitors to fully reduce the output impedance of the current transformer so that the induced current can be fully output. The output of the impedance converter has a higher output impedance and a higher output voltage, which can supply power for the switching voltage and the energy storage capacitor.

According to an embodiment of the present invention: the impedance converter is a DC-DC converter, which is generally called a DC-DC converter.

According to an embodiment of the present invention: the impedance converter is an integrated voltage boosting chip.

According to an embodiment of the present invention: the impedance converter has a signal terminal that can be closed, and the impedance converter is shorted when the induced current is large. The signal terminal that can be turned off is a comparator; when the induced current is large, the impedance converter is short-circuited through a short-circuit switch tube.

The invention has the advantage of adopting an impedance converter, which solves the problem of input and output impedance matching. Therefore, when the mains current is very small, the induced current of the current transformer is small and a self-generated power supply can also be established. Completed the invention task better.

Detailed ways

The technical solution of the present invention will be further described below in conjunction with the embodiments.

The impedance converter is a DC-DC converter, which is generally called a DC-DC converter with high efficiency.

The impedance converter is an integrated voltage boost chip. The chip is widely used in mobile phone circuits, so that when the voltage of the mobile phone battery decreases, the voltage can be raised to the required voltage, so as to make full use of the residual energy of the battery.

The impedance converter has a signal terminal that can be turned off, so that the impedance converter is shorted when the induced current is large. So there is a comparator, and there is a shorted switch. Unnecessary overvoltage generated by the self-generated power supply can be avoided.

Embodiment 1: A self-generated power supply for a power circuit breaker, including several current transformers, switching power supplies, and energy storage capacitors, is characterized in that it is between the output power supply of the current transformer, the switching power supply, and the input end of the energy storage capacitor Add a first-stage impedance converter to fully reduce the output impedance of the current transformer, so that the induced current can be fully output. The output of the impedance converter has a higher output impedance and a higher output voltage, which can supply power for the switching voltage and the energy storage capacitor.

Embodiment 2: In this embodiment, the impedance converter is a DC-DC converter, which is generally called a DC-DC converter, and the efficiency of the DC-DC converter is relatively high.

Embodiment 3: In this embodiment, the impedance converter is an integrated voltage boosting chip. The chip is widely used in mobile phone circuits, so that when the voltage of the mobile phone battery decreases, the voltage can be raised to the required voltage, so as to make full use of the residual energy of the battery.

Embodiment 4: In this embodiment, the impedance converter has a signal terminal that can be turned off, so that the impedance converter is shorted when the induced current is large. The signal terminal that can be closed can be a comparator; when the induced current is large, the impedance converter is short-circuited through a short-circuit switch tube. When the induced current is large, the impedance converter can be short-circuited to avoid unnecessary overvoltage generated by the self-generated power supply.

The embodiments described herein can be combined without conflicting with each other to better accomplish the inventive task.

The above-mentioned embodiments are provided for those who are familiar with the field to implement or use the present invention, and those who are familiar with the art can make various modifications or changes to the above-mentioned embodiments without departing from the inventive idea of the present invention. The scope of protection of the present invention is not limited by the above-mentioned embodiments, but should be the maximum scope consistent with the innovative features mentioned in the claims.

Claims (6)

1. A self-generated power supply for a power circuit breaker, comprising several current transformers, switching power supplies, and energy storage capacitors, characterized in that: add a stage between the current transformers, the switching power supply, and the energy storage capacitors An impedance transformer that reduces the output impedance of the current transformer. 2. The self-generated power supply for a power circuit breaker according to claim 1, wherein the impedance converter is a DC-DC converter. 3. The self-generated power supply for power circuit breakers according to claim 1, characterized in that: said impedance converter is an integrated voltage boosting chip. 4. The self-generated power supply for a power circuit breaker according to claim 1, characterized in that: said impedance converter has a signal terminal that can be closed, and the impedance converter is shorted when the induced current is large. 5. The self-generated power supply for a power circuit breaker as claimed in claim 4, wherein the signal terminal of the impedance converter that can be closed is a comparator. 6. The self-generated power supply for a power circuit breaker as claimed in claim 4, characterized in that: when the induced current is large, the impedance converter is short-circuited through a short-circuit switch tube.