An ultra-high-speed hybrid electromagnetic tripping device and its control method

Abstract

The present invention relates to an ultra-high-speed hybrid electromagnetic tripping device, wherein the additional winding circuit includes an additional winding, a capacitor, and multiple groups of thyristor modules. The present invention also relates to a control method for an ultra-high-speed hybrid electromagnetic tripping device, wherein under normal operating conditions, the thyristor module is in an 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 direction of the magnetic flux induced in the iron core by the additional winding current and the current-carrying bus current is consistent, thereby enhancing the iron core magnetic field strength, increasing the electromagnetic force acting on the moving iron core, and achieving ultra-high-speed tripping. Compared with existing tripping devices, the present invention is scientifically and rationally designed, and has the advantages of rapid action, small dispersion of tripping time, and high reliability.

Description

Technical Field

[0001] The present 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 busbar current on the moving iron core to achieve tripping. After a short circuit occurs, the current carrying busbar current I1 increases, 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 achieve tripping.

[0003] However, the tripping time t of the existing overcurrent tripping device is act The current rise rate dI1 / dt of the current-carrying busbar exhibits severe dispersion. In the event of a remote fault or a high-resistance fault, the current rise rate dI1 / dt of the current-carrying busbar is low, and the overcurrent trip device cannot operate quickly. This causes the system to experience fault current for a long time, shortening the life of the system equipment and increasing the risk of equipment overheating and damage, which is detrimental to reliable system operation. Existing overcurrent trip devices suffer from insufficient tripping speed and large dispersion in tripping time. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an ultra-high-speed hybrid electromagnetic tripping device and a control method thereof, which realize ultra-high-speed tripping and have the advantages of rapid action, small tripping time dispersion 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 includes a static iron core, a current-carrying busbar, a reaction spring device and a shift fork. The shift fork, moving iron core, current-carrying busbar and reaction spring device are arranged on the static iron core in order from top to bottom. The static iron core is also provided with an adjustment block. It is characterized in that an additional winding circuit is provided at the bottom end of the static iron core, and the additional winding circuit is composed of an additional winding, a capacitor and multiple groups of thyristor modules.

[0007] Moreover, the multiple groups of thyristor modules include positive thyristor module 1, positive thyristor module 4, negative thyristor module 2 and negative thyristor module 3. The positive thyristor module 1, positive thyristor module 4, negative thyristor module 2 and negative thyristor module 3 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 is 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 busbar and compare whether the value of I1 exceeds the preset current trigger value I th ;

[0012] 2) The current I1 of the carrying bus exceeds 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 based on 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 iron 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 I1 of the carrying bus increases rapidly. When the current I1 of the carrying bus 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 to multiple groups of thyristor modules and capacitors to form an additional winding circuit. Under normal operating conditions, the thyristor modules are in the off state, and no current flows 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 conduct; 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 conduct, causing the capacitor to discharge into the additional winding and ensuring that the direction of the magnetic flux induced in the iron core by the additional winding current and the current-carrying bus current is consistent, thereby enhancing the iron core magnetic field strength and increasing the electromagnetic force acting on the moving iron core, achieving ultra-high-speed tripping, with the advantages of rapid action, small tripping time dispersion, and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural diagram of an existing overcurrent tripping 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 will be further described in detail below through specific examples. The following examples are only illustrative and not restrictive, and the scope of protection of the present invention cannot be limited thereto.

[0026] An ultra-high-speed hybrid electromagnetic tripping device includes a static iron core, a current-carrying busbar, a reaction spring device and a shift fork. The shift fork, moving iron core, current-carrying busbar and reaction spring device are arranged on the static iron core in order from top to bottom. The static iron core is also provided with an adjustment block. Its innovation lies in: an additional winding circuit is provided at the bottom end of the static iron core, and the additional winding circuit is composed of an additional winding, a capacitor and multiple groups of thyristor modules.

[0027] Moreover, the multiple groups of thyristor modules include positive thyristor module 1, positive thyristor module 4, negative thyristor module 2 and negative thyristor module 3. The positive thyristor module 1, positive thyristor module 4, negative thyristor module 2 and negative thyristor module 3 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 a thyristor alone; or the thyristor module is composed of a thyristor and a diode connected in anti-parallel.

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

[0030] 2) The current I1 of the carrying bus exceeds 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 based on 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 iron core.

[0033] 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;

[0034] After the fault occurs, the current I1 of the carrying bus increases rapidly. When the current I1 of the carrying bus 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 2.1mF, 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, and the thyristors in thyristor module 1 and 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 iron 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 in a specific embodiment of the present invention is shown as follows: m , spring reaction force F k , waveforms 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 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, the actual tripping time of the ultra-high-speed hybrid electromagnetic tripping device is t act The tripping time of the existing overcurrent tripping device is 1.7ms, and the tripping time of the existing overcurrent tripping 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 provides an ultra-high-speed hybrid electromagnetic tripping device and control method. An additional winding is installed on the static iron core, and the lead-out end of the additional winding is indirectly connected to multiple groups of thyristor modules and capacitors to form an additional winding circuit. Under normal operating 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 direction of the magnetic flux induced in the iron core by the additional winding current and the current-carrying bus current is consistent, thereby enhancing the iron core magnetic field strength and increasing the electromagnetic force acting on the moving iron core, thereby achieving ultra-high-speed tripping, which 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 understand 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. A control method for an ultra-high-speed hybrid electromagnetic tripping device, characterized in that: The ultra-high-speed hybrid electromagnetic tripping device includes a static iron core, a current-carrying busbar, a reaction spring device, and a shift fork. The shift fork, moving iron core, current-carrying busbar, and reaction spring device are sequentially arranged on the static iron core from top to bottom. The static iron core is also provided with an adjustment block. The device is characterized in that an additional winding circuit is provided at the bottom end of the static iron core, and the additional winding circuit is composed of an additional winding, a capacitor, and multiple groups of thyristor modules. The multiple groups of thyristor modules include a positive thyristor module 1, a positive thyristor module 4, a negative thyristor module 2, and a negative thyristor module 3. The positive thyristor module 1, the positive thyristor module 4, the negative thyristor module 2, and the negative thyristor module 3 are connected via a capacitor to form a bridge circuit, and the bridge circuit completes bidirectional control of the current in the additional winding; The thyristor module is composed of thyristors alone; The thyristor module is composed of a thyristor and a diode connected in anti-parallel; The steps of the control method are: 1) Continuously monitor the current I1 of the current-carrying busbar and compare whether the value of I1 exceeds the preset current trigger value I th ; 2) The current I1 of the carrying bus exceeds 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 based on 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 iron core.

2. The control method of the ultra-high-speed hybrid electromagnetic tripping device according to claim 1, characterized in that: 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; After the fault occurs, the current I1 of the carrying bus increases rapidly. When the current I1 of the carrying bus 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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