CN201302946Y - Permanent magnetic actuator for vacuum circuit breaker supplied with power by super capacitor - Google Patents

Abstract

The permanent magnet operating mechanism of the vacuum circuit breaker powered by a supercapacitor includes an opening-closing coil operating unit, a power supply and a power control module. The opening-closing coil operating unit is the actuator of the permanent magnet operating mechanism, and the power is supplied to the permanent magnet The operating mechanism branch-closing coil operation unit provides power, and the power control module controls the power supply to supply and cut off the coil of the branch-closing coil operation unit; the feature is that the power supply adopts a super capacitor bank, and the super capacitor bank includes multiple series The supercapacitor monomer; the power control module includes a controller composed of a programmable element FPGA, a controllable power electronic switch and a freewheeling diode, and the controller, a controllable power electronic switch and a freewheeling diode are electrically connected in sequence; opening-closing The coil operation unit includes a moving iron core, a static iron core, a permanent magnet, a closing coil, an operating link, and an opening coil; the upper part of the permanent magnet is the opening coil, the lower part is the closing coil, and the moving iron core passes through the permanent magnet to separate The central hole of the brake coil and the closing coil, the operating connecting rod is connected with the moving iron core.

Description

Permanent magnet operating mechanism of vacuum circuit breaker powered by supercapacitor

technical field

The utility model relates to a permanent magnet operating mechanism of a vacuum circuit breaker, in particular to a permanent magnet operating mechanism of a vacuum circuit breaker used for energy supply by a low-voltage large-capacity supercapacitor in a power distribution and power supply system.

Background technique

In power distribution and power supply systems, vacuum circuit breakers are widely used. The permanent magnet operating mechanism is an important part of the vacuum circuit breaker. There is only one moving part during operation, and there is no need for a mechanical release and locking device. There are few fault sources and high reliability.

There are two kinds of power sources for existing vacuum circuit breakers, one is to use electrolytic capacitors, and the other is to use batteries. Battery as a power source needs to consider overcharging, overdischarging and other issues. The charging circuit and protection circuit are relatively complicated. In addition, the battery has low power density, short life, high maintenance costs, and mostly uses heavy metals or acid-base materials, which is not conducive to environmental protection. ; The energy storage density of electrolytic capacitors is low, and the capacity of a single capacitor is mostly at the mF level. In practical applications, the electrolytic capacitors that supply energy to permanent magnet mechanisms are generally DC 220V. The industry generally believes that the most significant defect of permanent magnet mechanisms is the storage capacity. The quality problem of the energy capacitor, the leakage current of the electrolytic capacitor is relatively large, and it must be connected to the grid for real-time charging during use to ensure the stability of the terminal voltage of the electrolytic capacitor, otherwise its stored electric energy will not be able to complete a complete opening, closing and opening operation Circulation, for the vacuum circuit breaker on the outdoor pole, the on-site power supply is not easy to solve.

Contents of the invention

The purpose of this utility model is to provide a permanent magnet operating mechanism of a vacuum circuit breaker powered by a supercapacitor. The supercapacitor is an energy storage element whose performance is between that of a battery and an electrolytic capacitor. The energy density is greater than that of electrolytic capacitors, and has the characteristics of long service life, maintenance-free and environmental protection.

In order to achieve the above purpose, the permanent magnet operating mechanism of the vacuum circuit breaker powered by the supercapacitor of the present invention includes an opening-closing coil operating unit, a power supply and a power control module, and the opening-closing coil operating unit is a permanent magnet operating unit. For the actuator of the mechanism, the power supply provides power to the opening-closing coil operating unit of the permanent magnet operating mechanism, and the power control module controls the power supply to supply and cut off the coil of the opening-closing coil operating unit; its characteristics are:

The power supply adopts a supercapacitor bank, and the supercapacitor bank includes multiple supercapacitor monomers connected in series;

The power supply control module includes a controller composed of a programmable element FPGA, a controllable power electronic switch and a freewheeling diode, and the controller, the controllable power electronic switch and the freewheeling diode are electrically connected in sequence;

The opening-closing coil operation unit includes a moving iron core, a static iron core, a permanent magnet, a closing coil, an operating link, and an opening coil; the upper part of the permanent magnet is the opening coil, the lower part is the closing coil, and the moving iron core wears Through the central hole of the permanent magnet opening coil and the closing coil, the operating connecting rod is connected with the moving iron core.

The permanent magnet operating mechanism of a vacuum circuit breaker powered by a supercapacitor as described above is characterized in that the supercapacitor bank is composed of 18 DC 48V supercapacitor monomers with a terminal voltage of 2.7V connected in series.

The permanent magnet operating mechanism of the vacuum circuit breaker powered by a supercapacitor as described above is characterized in that the opening and closing coils are a structure in which multiple strands of thin wires are transposed and wound.

In order to change the capacitor that had to use 220V power supply into a 48V low-voltage supercapacitor, and keep the external dimensions of the existing permanent magnet mechanism unchanged, that is, to keep the diameter of the coil, in order to maintain a certain number of ampere turns, by reducing the voltage, At the same time increase the diameter of the coil to achieve. The selection of the coil wire diameter takes into account both the flow rate and the volume of the mechanism. In order to reduce the eddy current loss of thick wires, multiple thin wires can be transposed and wound. The voltage of a single supercapacitor is low and the capacitance is large.

The power supply of the permanent magnet operating mechanism of the permanent magnet operating mechanism of the supercapacitor-powered vacuum circuit breaker of the present utility model adopts a supercapacitor bank, and the currently widely used DC 48V supercapacitor bank is selected, and 18 supercapacitors with a terminal voltage of 2.7V The capacitor monomers are connected in series.

The power supply control module of the permanent magnet operating mechanism of the vacuum circuit breaker powered by a supercapacitor of the utility model includes a controller composed of a programmable element FPGA, a controllable power electronic switch and a freewheeling diode. The controller composed of programmable elements FPGA, through the set preset program, cooperates with the controllable power electronic switch to realize the constant voltage of energy storage capacitor charging, over-charge cut-off protection, local closing and remote closing and opening, Closing and opening remote signal output, combined with the automatic comprehensive protection of the power system to implement various protection closing and reclosing operations and other functions. When the opening and closing coil loses power suddenly, since the opening and closing coil is an inductive element, the sudden change of current will generate overvoltage, and the freewheeling diode can be used to solve the overvoltage problem.

The permanent magnet operating mechanism of the vacuum circuit breaker powered by the supercapacitor of the utility model can use a low-voltage large-capacity supercapacitor as the energy supply power supply of the permanent magnet operating mechanism of the vacuum circuit breaker. Due to the high energy storage density of the supercapacitor, the leakage current is small , can reliably guarantee the power supply of the permanent magnet mechanism, and is easier to maintain. By optimizing the coil structure parameters and reducing the voltage of the supercapacitor bank, the cost of using supercapacitors can be greatly reduced.

Description of drawings

Fig. 1 is a schematic diagram of a permanent magnet operating mechanism of a vacuum circuit breaker powered by a supercapacitor according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view of a multi-strand wire wound opening and closing coil of a permanent magnet operating mechanism of a vacuum circuit breaker powered by a supercapacitor according to the present invention.

Detailed ways

Description of the marks in Figure 1: moving iron core 1, static iron core 2, permanent magnet 3, closing coil 4, operating connecting rod 5, opening coil 6.

Explanation of the marks in Fig. 2: incoming wire terminal 7, wire 8, wire 9, wire 10, wire outlet 11.

As shown in Figure 1, in the opening-closing coil operating unit of the permanent magnet operating mechanism described in the utility model, when the circuit breaker is in the opening position, the moving iron core 1 is in the upper part, and the moving iron core 1 and the upper static The gap between the iron cores 2 is small, and most of the magnetic lines of force formed by the permanent magnets 3 are concentrated on the upper part, thereby generating a great upward attractive force, and the moving iron core 1 is tightly adsorbed on it. When the circuit breaker is about to close, the closing coil 4 generates an induced magnetic field through the closing current, and the magnetic field generates a downward attraction to the moving iron core 1, making the moving iron core 1 start to move downward, and at the same time drives the operating connecting rod 5 actions. When the moving iron core 1 reaches the lower part, the magnetic field generated by the permanent magnet 3 keeps the moving iron core 1 in the lower position. The contacts in the interrupter chamber of the circuit breaker are closed by operating the connecting rod 5 . So far, the circuit breaker completes the closing operation. Based on the same principle, when the opening coil 6 is energized, the moving iron core 1 moves upwards, and is also kept in the opening position by the permanent magnet 3 . Reasonable selection of the wire diameter and the number of turns of the closing coil 4 and the opening coil 6 can optimize the parameters of the coil itself, reduce the voltage of the supercapacitor bank, and greatly reduce the cost of using supercapacitors.

The opening and closing of the vacuum circuit breaker mainly depends on the excitation ampere-turns in the opening and closing coils. The ampere-turns of the coil is proportional to the product of the power supply voltage and the square of the coil diameter, and inversely proportional to the diameter of the coil. In order to change the capacitor that originally had to use 220V working power to a 48V low-voltage supercapacitor, if the external dimensions of the existing permanent magnet mechanism remain unchanged, that is, the diameter of the coil winding is maintained, in order to maintain a certain number of ampere turns, the voltage can be reduced , while increasing the coil diameter to achieve. The selection of the coil wire diameter should take into account the flow rate and the volume of the mechanism. In order to reduce the eddy current loss of thick wires, multiple thin wires can be transposed and wound together. Take three wires wound in parallel as an example, 7 is the incoming wire end, 11 is the outgoing wire end, and 8, 9, and 10 are three wires respectively. . Since the positions of the parallel wires in the leakage magnetic field are different, the induced electromotive force is not equal, which will cause a circulating current between the parallel wires, thereby increasing the loss of the wires. If the circulating current in the parallel wires is eliminated, the parallel wires The wires must be transposed.

The voltage of a single supercapacitor is low and the capacitance is large. In the case of a certain application voltage, the number of series connections is certain. At this time, the capacity of a single supercapacitor can be selected taking into account both the flow rate and the cost.

The controllable power electronic switching tube in the power control module can be any one of insulated gate bipolar thyristor, gate turn-off thyristor, and integrated gate commutation thyristor. In the utility model, a large-capacity supercapacitor is used as the working power supply, and its discharge current is two to three times that of the conventional permanent magnet mechanism power supply. For low-voltage and high-current control power switch tube selection, both flow and cost should be considered.

Claims (3)

1. A permanent magnet operating mechanism of a vacuum circuit breaker powered by a supercapacitor, comprising an opening-closing coil operating unit, a power supply and a power control module, the opening-closing coil operating unit being the actuator of the permanent magnet operating mechanism, The power supply provides power to the opening-closing coil operating unit of the permanent magnet operating mechanism, and the power control module controls the power supply to supply and cut off the coil of the opening-closing coil operating unit; its characteristics are: The power supply adopts a supercapacitor bank, and the supercapacitor bank includes multiple supercapacitor monomers connected in series; The power supply control module includes a controller composed of a programmable element FPGA, a controllable power electronic switch and a freewheeling diode, and the controller, the controllable power electronic switch and the freewheeling diode are electrically connected in sequence; The opening-closing coil operation unit includes a moving iron core, a static iron core, a permanent magnet, a closing coil, an operating link, and an opening coil; the upper part of the permanent magnet is the opening coil, the lower part is the closing coil, and the moving iron core wears Through the central hole of the permanent magnet opening coil and the closing coil, the operating connecting rod is connected with the moving iron core. 2. The permanent magnet operating mechanism of a vacuum circuit breaker powered by a supercapacitor according to claim 1, wherein the supercapacitor bank is composed of 18 DC 48V supercapacitor monomers connected in series with a terminal voltage of 2.7V. become. 3. The permanent magnet operating mechanism of a vacuum circuit breaker powered by a supercapacitor according to claim 1 or 2, characterized in that the opening and closing coils are multi-strand thin wires transposed and wound.

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