Grounding full-compensation arc extinguishing device based on YNyn6 type transformer
Through the grounding fully compensated arc suppression device based on the YNyn6 type transformer, the YY type wiring form of the transformer is used to output a voltage signal opposite to the fault, which solves the problems of complex ground fault handling structure and low reliability in the existing technology, and achieves Efficient full compensation and stability improvement for single-phase ground faults.
Patent Information
- Application Number
- CN202421090139.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-20
- Publication Date
- 2025-01-24
- Estimated Expiration
- 2034-05-20
AI Technical Summary
The existing active fully compensated devices for grounding faults have problems such as complex structure and low reliability. Especially when dealing with single-phase grounding faults, they need to rely on power electronic equipment for inverter output, resulting in large losses and poor reliability.
Adopt a full compensation arc anti -elimination device based on the ground -based transformer, and outputs through the yy -type wiring form output through the yyn6 transformer, which is the same as the fault value and the opposite voltage signal. Compensation.
There is no need to use an inverter power supply. Full compensation of single-phase ground faults can be achieved only through the YNyn6 transformer and phase selection switch group. The design has a simple structure, high reliability, good stability, and avoids phase deviation.
Smart Images
Figure CN222395450U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of single-phase grounding protection devices for distribution networks, in particular to a grounding full-compensation arc extinguishing device. Background Art
[0002] The active full compensation device for ground fault is generally composed of a power transformer, a step-up transformer, a vacuum contactor, an active power compensator (APC), a controller, etc. When a single-phase ground fault occurs, the controller adjusts the output voltage of the active power compensator, which can compensate the voltage and current at the single-phase ground fault point to close to 0, completely eliminate the arc when a single-phase ground fault occurs, and can also use the disturbance method to accurately select the line, which is a better solution to the single-phase ground fault. The advantage of using active equipment is that the output voltage is output through a high-power power electronic device inverter, which has the characteristics of no step difference in output voltage and high adjustment accuracy; but power electronic equipment also has other problems, such as large losses and low reliability of power electronic equipment. Utility Model Content
[0003] The technical problem to be solved by the utility model is to provide a grounding full-compensation arc-extinguishing device based on a YNyn6 type transformer with simple structure and high reliability.
[0004] In order to solve the above technical problems, the technical solutions adopted by the present utility model are as follows.
[0005] A grounding full-compensation arc-extinguishing device based on a YNyn6 transformer comprises a controller, a YNyn6 transformer, an analog quantity acquisition unit, a phase selection switch group, and an intervention unit for preventing the system from resonating and capable of switching capacitors into the system to calculate the system capacitance and current. The primary winding of the YNyn6 transformer is connected to the three-phase bus in a Y-type connection manner, and a voltage regulating tap is provided, and the voltage regulating tap changes the connection position under the drive of a driving mechanism; the secondary winding of the YNyn6 transformer is connected in a Y-type connection manner, and the secondary winding is connected to the neutral point of the primary winding of the YNyn6 transformer via the phase selection switch group; the input end of the controller is connected to the output end of the analog quantity acquisition unit for collecting bus voltage, neutral point voltage and neutral point current, and the output end of the controller is respectively connected to the controlled end of the phase selection switch group, the driving mechanism and the intervention unit.
[0006] The above-mentioned grounding full-compensation arc-extinguishing device based on the YNyn6 type transformer, the analog quantity acquisition unit includes a voltage transformer respectively connected between each phase line of the busbar and the ground and between the neutral point of the primary winding of the YNyn6 type transformer and the ground, and a current transformer connected in series between the common terminal of the phase selection switch group and the neutral point of the primary winding of the YNyn6 type transformer.
[0007] The above-mentioned grounded full-compensation arc-extinguishing device based on the YNyn6 type transformer, the phase selection switch group includes an A-phase switch, a B-phase switch and a C-phase switch arranged in parallel, wherein one end of the A-phase switch, the B-phase switch and the C-phase switch are respectively connected to the three phases of the secondary winding of the YNyn6 type transformer, and the other end is commonly connected to the neutral point of the primary winding of the YNyn6 type transformer; the controlled end of each phase switch is respectively connected to the output end of the controller.
[0008] The above-mentioned grounding full-compensation arc-extinguishing device based on the YNyn6 type transformer, the intervention unit includes a capacitor switching branch and a resistor switching branch arranged in parallel, the capacitor switching branch includes a capacitor and a first switch connected in series, the resistor switching branch includes a resistor and a second switch connected in series, the controlled ends of the first switch and the second switch are respectively connected to the output ends of the controller, and the common end of the first switch and the second switch is grounded.
[0009] Due to the adoption of the above technical scheme, the technical progress achieved by the present invention is as follows.
[0010] The utility model does not need to use an inverter with a power electronic device. It can fully compensate for the single-phase grounding fault of the distribution network only through the cooperation of the YNyn6 transformer and the phase selection switch group. The transformer adopts a YY type wiring form, and outputs a voltage signal with the same amplitude and opposite phase as the fault phase and injects it into its own neutral point, forcing the fault phase voltage to drop to 0V, thereby achieving the purpose of full compensation for single-phase grounding faults, without phase shift, good stability, simple overall design structure and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 This is the system wiring diagram of the utility model;
[0012] Figure 2 This is an electrical schematic diagram of the intervention unit of the utility model.
[0013] Among them: BYQ. YNyn6 type transformer, PT1-PT4. voltage transformer, LH. current transformer, KA. A phase switch, KB. B phase switch, KC. C phase switch, KZQ. controller, R. resistor, C. capacitor, K1. first switch, K2. second switch. DETAILED DESCRIPTION
[0014] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0015] A grounding full compensation arc extinguishing device based on a YNyn6 transformer comprises a controller KZQ, a YNyn6 transformer BYQ, an analog quantity acquisition unit, a phase selection switch group and an intervention unit, wherein the phase selection switch group comprises an A-phase switch KA, a B-phase switch KB and a C-phase switch KC arranged in parallel, the analog quantity acquisition unit comprises a voltage transformer group and a current transformer LH, the intervention unit comprises a capacitor switching branch and a resistor switching branch arranged in parallel, and the connection relationship between the above electrical devices is as follows Figure 1 shown.
[0016] The primary winding of the YNyn6 transformer BYQ is connected to the three-phase bus in a Y-type connection mode, and a voltage-regulating tap is provided. The voltage-regulating tap changes its connection position under the drive of a driving mechanism. The controlled end of the driving mechanism is connected to the output end of the controller. The driving mechanism drives the voltage-regulating tap to move under the instruction of the controller. The secondary winding of the YNyn6 transformer BYQ is connected in a Y-type connection mode. The secondary winding is connected to the neutral point of the primary winding of the YNyn6 transformer BYQ through a phase selection switch group. In the utility model, the driving mechanism can be a load regulating switch, etc.
[0017] The analog quantity acquisition unit is mainly used to collect system voltage and current values. The voltage transformer group includes voltage transformers PT1-PT4. Voltage transformers PT1-PT3 are respectively connected between each phase line of the busbar and the ground to collect the real-time voltage of each phase line; voltage transformer PT4 is connected between the neutral point of the primary winding of the YNyn6 transformer BYQ and the ground to collect the voltage change of the neutral point of the primary winding of the YNyn6 transformer BYQ; current transformer LH is connected in series between the common terminal of the phase selection switch group and the neutral point of the primary winding of the YNyn6 transformer BYQ to collect the current value of the neutral point of the primary winding of the YNyn6 transformer BYQ. The signal ends of the above-mentioned current transformers and each voltage transformer are respectively connected to the input end of the controller to send the collected analog signals to the controller.
[0018] One end of the A-phase switch KA, the B-phase switch KB, and the C-phase switch KC in the phase selection switch group are respectively connected to the three phases of the secondary winding of the YNyn6 transformer BYQ, and the other end is commonly connected to the neutral point of the primary winding of the YNyn6 transformer BYQ, and is used to select the compensation signal to be injected into the faulty phase under the instruction of the controller; the controlled end of each phase switch is respectively connected to the output end of the controller.
[0019] The intervention unit is used to switch capacitors to the system to calculate the system capacitance when the system is operating normally, and to prevent the system from resonating after the system grounding disappears. The capacitor switching branch includes a capacitor C and a first switch K1 connected in series, and the resistor switching branch includes a resistor R and a second switch K2 connected in series. The controlled ends of the first switch K1 and the second switch K2 are respectively connected to the output end of the controller, and the common end of the first switch K1 and the second switch K2 is grounded. Figure 2 shown.
[0020] The working principle of the utility model is as follows.
[0021] When the system is operating normally, the controller monitors the system bus voltage information in real time, controls the switching of capacitor C through the first switch K1 according to the collected value, and then calculates the system capacitor current. According to the calculation result, the controller adjusts the primary side voltage regulating tap position of YNyn6 transformer BYQ to the appropriate gear by controlling the driving mechanism to realize the transformation ratio adjustment of YNyn6 transformer and fine-tune the output voltage.
[0022] When a single-phase grounding fault occurs in the system, the controller KZQ judges the phase and closes the phase switch KA, KB or KC corresponding to the fault at the same time. The YNyn6 transformer BYQ outputs a voltage signal with the same amplitude and opposite phase as the fault phase, forcing the fault phase voltage to drop to 0V, thereby achieving full compensation for the single-phase grounding fault.
[0023] When the single-phase grounding of the system disappears, the controller KZQ controls the phase switch KA, KB or KC to exit, and at the same time controls the second switch K2 in the intervention unit to input the resistor R to clamp the neutral point voltage to prevent system resonance.
[0024] The utility model can fully compensate for the single-phase grounding fault of the distribution network by using only one YNyn6 transformer, without phase shift and with good stability; the switch combination form is optimized and the control logic is concise; the overall design structure is simple and the reliability is high.
Claims
1. A grounding full compensation arc extinguishing device based on a YNyn6 transformer, including a controller (KZQ), characterized in that: It also includes a YNyn6 transformer (BYQ), an analog quantity acquisition unit, a phase selection switch group, and an intervention unit for preventing the system from resonating and being able to switch capacitors to the system to calculate the system capacitance. The primary winding of the YNyn6 transformer (BYQ) is connected to the three-phase bus in a Y-type connection manner, and a voltage regulating tap is provided, and the voltage regulating tap changes its connection position under the drive of a driving mechanism; the secondary winding of the YNyn6 transformer (BYQ) is connected in a Y-type connection manner, and the secondary winding is connected to the neutral point of the primary winding of the YNyn6 transformer (BYQ) via the phase selection switch group; the input end of the controller (KZQ) is connected to the output end of the analog quantity acquisition unit for collecting bus voltage, neutral point voltage and neutral point current, and the output end of the controller (KZQ) is respectively connected to the controlled end of the phase selection switch group, the driving mechanism and the intervention unit.
2. According to claim 1, a grounding full compensation arc extinguishing device based on a YNyn6 type transformer is characterized in that: The analog quantity acquisition unit includes a voltage transformer respectively connected between each phase line of the busbar and the ground and between the neutral point of the primary winding of the YNyn6 transformer (BYQ) and the ground, and a current transformer (LH) connected in series between the common terminal of the phase selection switch group and the neutral point of the primary winding of the YNyn6 transformer (BYQ).
3. A grounding full compensation arc extinguishing device based on a YNyn6 type transformer according to claim 1, characterized in that: The phase selection switch group includes an A-phase switch (KA), a B-phase switch (KB) and a C-phase switch (KC) arranged in parallel, wherein one end of the A-phase switch (KA), the B-phase switch (KB) and the C-phase switch (KC) are respectively connected to the three phases of the secondary winding of the YNyn6 transformer (BYQ), and the other end is commonly connected to the neutral point of the primary winding of the YNyn6 transformer (BYQ); the controlled end of each phase switch is respectively connected to the output end of the controller.
4. A grounding full compensation arc extinguishing device based on a YNyn6 type transformer according to claim 1, characterized in that: The intervention unit comprises a capacitor switching branch and a resistor switching branch arranged in parallel, the capacitor switching branch comprises a capacitor (C) and a first switch (K1) connected in series, the resistor switching branch comprises a resistor (R) and a second switch (K2) connected in series, the controlled ends of the first switch (K1) and the second switch (K2) are respectively connected to the output ends of the controller, and the common end of the first switch (K1) and the second switch (K2) is grounded.