CN105048430B - Micro-grid connection switch auxiliary arc extinction device with control device of releasing automatically - Google Patents

Abstract

The invention discloses an auxiliary arc extinguishing device for a grid-connected switch of a microgrid with an automatic discharge control device, including a current transformer, an uncontrollable rectification circuit, a discharge circuit and a damping resistor; the primary side of the current transformer is connected to a PCC, The secondary side is connected to the input end of the uncontrollable rectification circuit, the output end of the uncontrollable rectification circuit is connected to the input end of the discharge circuit, the output end of the discharge circuit is connected to a damping resistor, and the damping resistor is grounded. The present invention will not lose the electric energy of the power grid when the micro-grid is in normal operation, and will automatically return to the state of the normal operation of the power grid after the arc is extinguished, so as to meet the needs of energy saving. Low maintenance.

Description

Auxiliary arc extinguishing device for grid-connected switch of microgrid with automatic discharge control device

technical field

The invention relates to an auxiliary arc extinguishing device for a grid-connected switch of a micro-grid with an automatic discharge control device, and belongs to the field of arc extinguishing when power electronics technology is applied to a grid-connected micro-grid or when a fault is removed.

Background technique

Existing arc extinguishing methods include liquid or gas arc blowing, multi-fracture arc extinguishing, vacuum arc extinguishing, and special medium arc extinguishing.

Now it is more common to use a multi-oil type arc extinguishing device, but this device consumes a lot of steel, oil, and volume; the oil-less type is easy to deteriorate, and often needs maintenance or oil replacement, and requires a set of oil treatment methods, which are not suitable for frequent operation; Compression The air-type structure is complex, the process and material requirements are high, the noise is loud when breaking, the maintenance cycle is long, and a compressed air device is required; the special medium type has strict requirements for technology and sealing, and has high requirements for materials; the process and materials of the vacuum type interrupter High standard. Generally speaking, the cost of traditional arc extinguishing devices is high, the technical requirements are strict, and the maintenance costs are high.

Contents of the invention

In order to solve the above technical problems, the present invention provides an auxiliary arc extinguishing device for a grid-connected switch of a microgrid with an automatic discharge control device.

In order to achieve the above object, the technical scheme adopted in the present invention is:

The microgrid grid-connected switch auxiliary arc extinguishing device with automatic discharge control device includes a current transformer, an uncontrollable rectification circuit, a discharge circuit and a damping resistor; the primary side of the current transformer is connected to the PCC, and the secondary side is connected to the PCC. The input end of the uncontrollable rectification circuit is connected, the output end of the uncontrollable rectification circuit is connected to the input end of the discharge circuit, the output end of the discharge circuit is connected to a damping resistor, and the damping resistor is grounded.

The uncontrollable rectification circuit is mainly composed of diodes.

The discharge circuit includes a capacitor, an IGBT, and a first resistor; one end of the first resistor is respectively connected to one end of the capacitor and the gate of the IGBT, and the collector of the IGBT is connected to the other end of the first resistor. The emitter of the IGBT is externally connected with a damping resistor, and the other end of the capacitor and the connection point between the first resistor and the IGBT collector are externally connected with an uncontrollable rectification circuit.

The beneficial effect achieved by the present invention: the present invention will not lose the electric energy of the power grid when the micro-grid is in normal operation, and will automatically return to the state of the normal operation of the power grid after the arc is extinguished, meeting the demand for energy saving. At the same time, compared with the traditional device, Low cost, low technical requirements, low maintenance costs.

Description of drawings

Fig. 1 is a circuit block diagram of the present invention.

Figure 2 is a circuit diagram of the bleeder circuit.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention.

As shown in Figure 1, the microgrid grid-connected switch auxiliary arc extinguishing device with automatic discharge control device includes a current transformer, an uncontrollable rectifier circuit, a discharge circuit and a damping resistor R.

The connection structure is as follows: the primary side of the current transformer is connected to PCC, the meaning of PCC is the common coupling point, the secondary side is connected to the input end of the uncontrollable rectification circuit, the output end of the uncontrollable rectification circuit is connected to the input of the discharge circuit The terminal is connected, the output terminal of the discharge circuit is connected to the damping resistor R, and the damping resistor R is grounded.

The above-mentioned uncontrollable rectification circuit is mainly composed of diodes, which is an existing circuit and will not be described in detail here.

The above discharge circuit is shown in Figure 2, including a capacitor C, an IGBT and a first resistor R1; one end of the first resistor R1 is respectively connected to one end of the capacitor C and the gate of the IGBT, and the collector of the IGBT is connected to the first resistor R1 The other end is connected, the emitter of the IGBT is externally connected to a damping resistor R, and the other end of the capacitor C and the connection point between the first resistor R1 and the IGBT collector are externally connected to an uncontrollable rectification circuit.

The working process of the above-mentioned device is as follows:

After the PCC is disconnected, the current I on the transmission line suddenly increases. When I>Im (Im is the operating current), the current transformer generates a higher voltage on the secondary side, which is discharged through the uncontrolled rectification circuit The capacitor C of the circuit generates a higher voltage that reaches or exceeds the turn-on voltage of the IGBT, so that the IGBT is turned on, so that the current flows through the damping resistor R, and finally achieves the shunt effect, so that the current in the transmission line is quickly reduced to achieve the purpose of arc extinguishing. When the current in the line is less than Im, the IGBT is automatically turned off without loss of grid energy.

The above-mentioned device will not lose the power of the grid when the micro-grid is in normal operation, and will automatically return to the state of the normal operation of the grid after the arc is extinguished, meeting the needs of energy saving. Low maintenance.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and modifications can also be made. It should also be regarded as the protection scope of the present invention.

Claims (3)

1. the micro-grid connection switch auxiliary arc extinction device with control device of releasing automatically, it is characterised in that：It is mutual including electric current Sensor, can not control rectifying circuit, leadage circuit and damping resistance；

The primary side of the current transformer is connected with PCC, secondary side with can not the input of control rectifying circuit be connected, it is described not The output end of controlled rectification circuit and the input of leadage circuit are connected, and output end and the damping resistance of the leadage circuit connect Connect, the damping resistance ground connection.

2. the micro-grid connection with control device of releasing automatically according to claim 1 switchs auxiliary arc extinction device, its It is characterised by：It is described can not control rectifying circuit mainly be made up of diode.

3. the micro-grid connection with control device of releasing automatically according to claim 1 switchs auxiliary arc extinction device, its It is characterised by：The leadage circuit includes electric capacity, IGBT and first resistor；One end of the first resistor respectively with electric capacity one End and IGBT gate pole connection, the colelctor electrode of the IGBT and the other end of first resistor are connected, the emitter stage of the IGBT External damping resistance, the other end and first resistor of the electric capacity and the external uncontrollable rectified current of the tie point of IGBT colelctor electrodes Road.