Ultrahigh-speed hybrid electromagnetic tripping device and control method thereof

Abstract

The invention relates to an ultra-high-speed hybrid electromagnetic tripping device. An additional winding circuit comprises an additional winding, a capacitor and a plurality of groups of thyristor modules. The invention further relates to a control method of the ultra-high-speed hybrid electromagnetic tripping device, and under the normal working condition, the thyristor module is in a turn-off state, and no current exists in the additional winding; after a fault occurs, when it is detected that the additional winding bears forward voltage, the first forward thyristor module and the fourth forward thyristor module are controlled to be conducted; when it is detected that the additional winding bears reverse voltage, the second negative thyristor module and the third negative thyristor module are controlled to be conducted, the capacitor discharges to the additional winding, it is ensured that the directions of magnetic flows inducted by the current of the additional winding and the current of the current-carrying bus in the iron core are consistent, the magnetic field intensity of the iron core is enhanced, and electromagnetic force acting on the movable iron core is increased; and ultra-high-speed tripping is realized. Compared with an existing tripping device, the tripping device is scientific and reasonable in design and has the advantages of being rapid in action, small in tripping time dispersity and high in reliability.

Description

Technical Field

[0001] The invention belongs to the technical field of electrical equipment, and in particular relates to an ultra-high-speed hybrid electromagnetic tripping device and a control method thereof. Background Art

[0002] Fast DC circuit breakers in DC drive systems are often equipped with overcurrent tripping devices. Existing overcurrent tripping devices rely on the electromagnetic force generated by the bus current on the moving iron core to achieve tripping. After a short circuit occurs, the current carrying bus current I1 rises, the magnetic field strength in the overcurrent tripping device core increases, and an upward electromagnetic force F is induced on the moving iron core. m The current carrying bus current I1 reaches the current trigger value I th After the electromagnetic force F m Exceeds spring reaction force F k and mechanical device resistance F r The moving iron core starts to move until the shift fork is pushed to release.

[0003] However, the tripping time t of the existing overcurrent release device is act Affected by the current rise rate dI1 / dt of the current-carrying busbar, it exhibits serious dispersion. Under remote faults or high-resistance faults, the current rise rate dI1 / dt of the current-carrying busbar is low, and the overcurrent release device cannot act quickly, causing the system to be subjected to fault current for a long time, shortening the life of the equipment in the system and increasing the risk of equipment overheating and damage, which is not conducive to the reliable operation of the system. Existing overcurrent release devices have the defects of insufficient tripping speed and large dispersion of tripping time. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide an ultra-high-speed hybrid electromagnetic tripping device and a control method thereof, so as to achieve ultra-high-speed tripping, and have the advantages of rapid action, small dispersion of tripping time and high reliability.

[0005] The present invention solves the technical problem by the following technical solutions:

[0006] An ultra-high-speed hybrid electromagnetic tripping device comprises a stationary iron core, a current-carrying busbar, a reaction spring device and a shift fork, wherein the shift fork, the moving iron core, the current-carrying busbar and the reaction spring device are sequentially arranged on the stationary iron core from top to bottom, and an adjustment block is also arranged on the stationary iron core, characterized in that an additional winding circuit is arranged at the bottom end of the stationary iron core, and the additional winding circuit is composed of an additional winding, a capacitor and a plurality of thyristor modules.

[0007] Moreover, the multiple groups of thyristor modules include positive thyristor module one, positive thyristor module four, negative thyristor module two and negative thyristor module three. The positive thyristor module one, positive thyristor module four, negative thyristor module two and negative thyristor module three are connected through capacitors to form a bridge circuit, and the bridge circuit completes bidirectional current control of the additional winding circuit.

[0008] Moreover, the thyristor module is composed of thyristors alone.

[0009] Moreover, the thyristor module is composed of a thyristor and a diode connected in anti-parallel.

[0010] A control method for an ultra-high-speed hybrid electromagnetic tripping device, characterized in that: applied to the ultra-high-speed hybrid electromagnetic tripping device, the control method comprises the following steps:

[0011] 1) Continuously monitor the current I1 of the current-carrying bus and compare whether the value of I1 exceeds the preset current trigger value I th ;

[0012] 2) The current carrying bus current I1 is detected to exceed the current trigger value I th After that, measure the induced voltage U2 across the additional winding and determine the direction of U2;

[0013] 3) Determine the direction of the current carrying bus current I1 according to the direction of the additional winding circuit voltage U2;

[0014] 4) Control the conduction state of the thyristors in each group of thyristor modules so that the capacitor starts to discharge into the additional winding circuit, ensuring that the direction of the magnetic flux generated by the additional winding current I2 is consistent with the direction of the magnetic flux in the core.

[0015] Moreover, under normal circumstances, the amplitude of the current carrying bus current I1 is low and does not exceed the current trigger value I th , the thyristors in all thyristor modules remain in the off state, there is no current in the additional winding, and the moving iron core is subjected to the electromagnetic force F m Lower, no displacement occurs;

[0016] After the fault occurs, the current carrying bus current I1 increases rapidly, and it is detected that the current carrying bus current I1 reaches the current trigger value I th After that, measure the induced voltage U2 across the additional winding and determine the direction of U2;

[0017] When the induced voltage U2 is in a positive direction, the thyristors in the forward thyristor module 1 and the forward thyristor module 4 are triggered to conduct, causing the capacitor to discharge to the additional winding to generate a positive current I2;

[0018] When the induced voltage U2 is negative, the thyristors in the negative thyristor module 2 and the negative thyristor module 3 are triggered to conduct, causing the capacitor to discharge to the additional winding to generate a negative current I2;

[0019] The magnetic flux generated by I2 increases the magnetic field strength in the core, increasing the electromagnetic force F borne by the moving core. m , accelerate the movement of the moving iron core and achieve ultra-high-speed tripping.

[0020] The positive effects that the present invention can produce are:

[0021] The present invention installs an additional winding on the static iron core, and the lead-out end of the additional winding is indirectly connected with multiple groups of thyristor modules and capacitors to form an additional winding circuit. Under normal working conditions, the thyristor module is in the off state, and there is no current in the additional winding. After a fault occurs, when it is detected that the additional winding is subjected to a positive voltage, the positive thyristor module 1 and the positive thyristor module 4 are controlled to be turned on; when it is detected that the additional winding is subjected to a reverse voltage, the negative thyristor module 2 and the negative thyristor module 3 are controlled to be turned on, so that the capacitor discharges to the additional winding and ensures that the additional winding current is consistent with the direction of the magnetic flux induced in the iron core by the current-carrying bus current, thereby enhancing the magnetic field strength of the iron core, increasing the electromagnetic force acting on the moving iron core, and realizing ultra-high-speed tripping, which has the advantages of rapid action, small dispersion of tripping time, and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of an existing overcurrent release device;

[0023] Figure 2 Schematic diagram of an ultra-high-speed hybrid electromagnetic tripping device according to an embodiment of the present invention;

[0024] Figure 3 This is a working diagram of the ultra-high-speed hybrid electromagnetic tripping control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below through specific examples. The following examples are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0026] An ultra-high-speed hybrid electromagnetic tripping device comprises a stationary iron core, a current-carrying busbar, a reaction spring device and a shift fork, wherein the shift fork, the moving iron core, the current-carrying busbar and the reaction spring device are arranged on the stationary iron core in order from top to bottom, and an adjustment block is also arranged on the stationary iron core. The innovation thereof lies in that an additional winding circuit is arranged at the bottom end of the stationary iron core, and the additional winding circuit is composed of an additional winding, a capacitor and a plurality of thyristor modules.

[0027] Moreover, the multiple groups of thyristor modules include positive thyristor module one, positive thyristor module four, negative thyristor module two and negative thyristor module three. The positive thyristor module one, positive thyristor module four, negative thyristor module two and negative thyristor module three are connected through capacitors to form a bridge circuit, and the bridge circuit completes bidirectional current control of the additional winding circuit.

[0028] The thyristor module is composed of thyristors alone; or the thyristor module is composed of thyristors and diodes connected in anti-parallel.

[0029] A control method for an ultra-high-speed hybrid electromagnetic tripping device, the innovation of which is: applied to the ultra-high-speed hybrid 1) continuously monitoring the current carrying bus current I1, comparing whether the value of I1 exceeds a preset current trigger value I th ;

[0030] 2) The current carrying bus current I1 is detected to exceed the current trigger value I th After that, measure the induced voltage U2 across the additional winding and determine the direction of U2;

[0031] 3) Determine the direction of the current carrying bus current I1 according to the direction of the additional winding circuit voltage U2;

[0032] 4) Control the conduction state of the thyristors in each group of thyristor modules so that the capacitor starts to discharge into the additional winding circuit, ensuring that the direction of the magnetic flux generated by the additional winding current I2 is consistent with the direction of the magnetic flux in the core.

[0033] Under normal circumstances, the current carrying bus current I1 has a low amplitude and does not exceed the current trigger value I th , the thyristors in all thyristor modules remain in the off state, there is no current in the additional winding, and the moving iron core is subjected to the electromagnetic force F m Lower, no displacement occurs;

[0034] After the fault occurs, the current carrying bus current I1 increases rapidly, and it is detected that the current carrying bus current I1 reaches the current trigger value I th After that, measure the induced voltage U2 across the additional winding and determine the direction of U2;

[0035] When the induced voltage U2 is in a positive direction, the thyristors in the forward thyristor module 1 and the forward thyristor module 4 are triggered to conduct, causing the capacitor to discharge to the additional winding to generate a positive current I2;

[0036] When the induced voltage U2 is negative, the thyristors in the negative thyristor module 2 and the negative thyristor module 3 are triggered to conduct, causing the capacitor to discharge to the additional winding to generate a negative current I2;

[0037] The magnetic flux generated by I2 increases the magnetic field strength in the core, increasing the electromagnetic force F borne by the moving core.m , accelerate the movement of the moving iron core and achieve ultra-high-speed tripping.

[0038] The present invention is simulated, and its parameters are set as follows: the capacitance value C in the additional winding circuit is 2.1 mF, the capacitance pre-charge voltage value U c0 =700V, additional winding turns n2 = 50, adjust the adjustment block and the reaction spring device to set the current trigger value I th =15kA.

[0039] When the current carrying bus current I1 reaches the current trigger value I th When the additional winding voltage U2 is detected and the direction of U2 is determined to be positive, the thyristors in the thyristor module 1 and the thyristor module 4 are triggered to turn on, so that the capacitor starts to discharge and a current I2 is generated in the additional winding. The direction of I2 is consistent with the magnetic flux generated in the core by the current-carrying bus current I1.

[0040] Figure 3 The electromagnetic force F of an ultra-high-speed hybrid electromagnetic tripping device and control method of the present invention in a specific embodiment is shown. m , Spring reaction force F k , waveform of additional winding current I2 and moving iron core displacement.

[0041] Figure 3 (a) shows the electromagnetic force F of the ultra-high-speed hybrid electromagnetic tripping device during the tripping process when the current carrying bus current I1 increases from 0A at a rate of 2kA / ms. m , Spring reaction force F k The waveform of the additional winding current I2 shows that at 7.5ms, the forward thyristor module 1 and the forward thyristor module 4 are triggered to conduct. At 9.2ms, the moving iron core moves to contact the shift fork. The actual tripping time is t act 1.7ms;

[0042] Figure 3 (b) shows the comparison of the action characteristics of the ultra-high-speed hybrid electromagnetic tripping device and the existing overcurrent tripping device. The structure of the existing overcurrent tripping device is as follows: Figure 1 As shown in Figure 2, the actual tripping time of the ultra-high-speed hybrid electromagnetic tripping device is t act The tripping time of the existing overcurrent release device is 1.7ms, and the tripping time of the existing overcurrent release device is 5.2ms.

[0043] It can be seen that the action speed of the ultra-high-speed hybrid electromagnetic tripping device is significantly faster than that of the existing overcurrent tripping device, and can achieve ultra-high-speed tripping.

[0044] The present invention discloses an ultra-high-speed hybrid electromagnetic tripping device and control method. An additional winding is installed on the static iron core. The lead-out end of the additional winding is indirectly connected with multiple groups of thyristor modules and capacitors to form an additional winding circuit. Under normal working conditions, the thyristor module is in the off state, and there is no current in the additional winding. After a fault occurs, when it is detected that the additional winding is subjected to a positive voltage, the positive thyristor module one and the positive thyristor module four are controlled to be turned on; when it is detected that the additional winding is subjected to a reverse voltage, the negative thyristor module two and the negative thyristor module three are controlled to be turned on, so that the capacitor discharges to the additional winding and ensures that the additional winding current is consistent with the direction of the magnetic flux induced in the iron core by the current-carrying bus current, thereby enhancing the magnetic field strength of the iron core, increasing the electromagnetic force acting on the moving iron core, and realizing ultra-high-speed tripping. It has the advantages of rapid action, small dispersion of tripping time, and high reliability.

[0045] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. An ultra-high-speed hybrid electromagnetic tripping device, comprising a stationary iron core, a current-carrying busbar, a reaction spring device and a shift fork, wherein the shift fork, the moving iron core, the current-carrying busbar and the reaction spring device are sequentially arranged on the stationary iron core from top to bottom, and an adjustment block is also arranged on the stationary iron core, characterized in that: An additional winding circuit is arranged at the bottom end of the static iron core, and the additional winding circuit is composed of an additional winding, a capacitor and a plurality of thyristor modules.

2. The ultra-high-speed hybrid electromagnetic tripping device according to claim 1, characterized in that: The multiple groups of thyristor modules include positive thyristor module one, positive thyristor module four, negative thyristor module two and negative thyristor module three. The positive thyristor module one, positive thyristor module four, negative thyristor module two and negative thyristor module three are connected through capacitors to form a bridge circuit, and the bridge circuit completes bidirectional control of the current in the additional winding.

3. The ultra-high-speed hybrid electromagnetic tripping device according to claim 1, characterized in that: The thyristor module is composed of thyristors alone.

4. The ultra-high-speed hybrid electromagnetic tripping device according to claim 1, characterized in that: The thyristor module is composed of a thyristor and a diode connected in anti-parallel.

5. A control method for an ultra-high-speed hybrid electromagnetic tripping device, characterized in that: Applied to the ultra-high-speed hybrid electromagnetic tripping device according to any one of claims 1 to 4, the control method comprises the following steps: 1) Continuously monitor the current I1 of the current-carrying bus and compare whether the value of I1 exceeds the preset current trigger value I th ; 2) The current carrying bus current I1 is detected to exceed the current trigger value I th After that, measure the induced voltage U2 across the additional winding and determine the direction of U2; 3) Determine the direction of the current carrying bus current I1 according to the direction of the additional winding circuit voltage U2; 4) Control the conduction state of the thyristors in each group of thyristor modules so that the capacitor starts to discharge into the additional winding circuit, ensuring that the direction of the magnetic flux generated by the additional winding current I2 is consistent with the direction of the magnetic flux in the core.

6. The control method of the ultra-high-speed hybrid electromagnetic tripping device according to claim 5, characterized in that: Under normal circumstances, the current carrying bus current I1 has a low amplitude and does not exceed the current trigger value I th , the thyristors in all thyristor modules remain in the off state, there is no current in the additional winding, and the moving iron core is subjected to the electromagnetic force F m Lower, no displacement occurs; After the fault occurs, the current carrying bus current I1 increases rapidly, and it is detected that the current carrying bus current I1 reaches the current trigger value I th After that, measure the induced voltage U2 across the additional winding and determine the direction of U2; When the induced voltage U2 is in a positive direction, the thyristors in the forward thyristor module 1 and the forward thyristor module 4 are triggered to conduct, causing the capacitor to discharge to the additional winding to generate a positive current I2; When the induced voltage U2 is negative, the thyristors in the negative thyristor module 2 and the negative thyristor module 3 are triggered to conduct, causing the capacitor to discharge to the additional winding to generate a negative current I2; The magnetic flux generated by I2 increases the magnetic field strength in the core, increasing the electromagnetic force F borne by the moving core. m , accelerate the movement of the moving iron core and achieve ultra-high-speed tripping.

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