Active filtering device

Abstract

The utility model relates to an active filtering device, and relates to the field of active filters. Comprising an active filtering compensator main body A, an active filtering compensator main body B and a single-door cabinet body, the active filtering compensator main body is installed in the single-door cabinet body, and two sets of supporting cross beams arranged at intervals are arranged in the single-door cabinet body. The front ends of the active filtering compensator main body A and the active filtering compensator main body B are respectively arranged on the upper side and the lower side of the supporting cross beam through the same connecting piece A, and the tail ends of the active filtering compensator main body A and the active filtering compensator main body B are respectively arranged on the upper side and the lower side of the supporting cross beam through the same connecting piece B. The utility model has the following beneficial effects: two groups of active filter compensator main bodies can share one supporting cross beam, the installation number of the supporting cross beams is reduced, the occupied space of the supporting cross beams is reduced, and the arrangement and installation of a plurality of active filter compensator main bodies are satisfied.

Description

Technical Field

[0001] This utility model relates to an active filtering device, and relates to the field of active filters. Background Technology

[0002] Due to the widespread application of power electronics technology in coal mine electrical equipment, especially the recent widespread adoption of permanent magnet synchronous motors and permanent magnet drums as a novel driving method in coal mines, frequency converters are being used extensively as controllers for permanent magnet motors (drums). However, the operating characteristics of frequency converters have led to severe harmonic pollution in the local power grid of mines. The harmonic pollution problem in the distribution network is becoming increasingly serious, reducing the power supply quality of power lines and even altering the performance of some power supply and consumption equipment, thus endangering the safe and economical operation of the power grid and the equipment itself. In an ideal AC power grid, the voltage of each phase changes periodically over time and exhibits a sinusoidal waveform. Coal mining enterprises and other power-consuming enterprises all desire to maintain an ideal sinusoidal voltage waveform. However, in reality, the increasingly widespread use of frequency converters in coal mine power supply and distribution networks causes the grid voltage to deviate from a sinusoidal waveform. The voltage and current waveforms are actually non-sinusoidal waves with varying degrees of distortion, resulting in severe harmonic pollution in the local power grid.

[0003] The hazards caused are as follows: ①. Seriously affects the leakage protection of the local power supply system; ②. Damages the insulation of the motor, causing the motor core to overheat; ③. Interferes with the communication quality of the mine; ④. Affects the transmission network of the mine.

[0004] A search of patent application number 202421196132.1 reveals a low-energy active filter device, comprising a low-energy active filter body for supporting and mounting components of the active filter device, and fixing bolts extending through the exterior of the low-energy active filter body for connecting a pre-installation cover. This invention includes an inner filter frame, an internal filter screen, a drive controller, a heat dissipation vent, cooling fan blades, a connecting rod, and a miniature telescopic air pump. In the off-state, the cooling fan blades of the low-energy active filter vent are closed, preventing external dust from entering the low-energy active filter body. After the low-energy active filter is activated, the drive controller controls the miniature telescopic air pump to extend and retract the connecting rod, causing the cooling fan blades to unfold within the heat dissipation vent. This opens the vent, allowing the heat accumulated inside the low-energy active filter body to dissipate smoothly through the heat dissipation vents on both sides.

[0005] Although the aforementioned patent can achieve dynamic tracking compensation and can compensate for both harmonics and reactive power, the current technology is not comprehensive and has the following drawbacks: it cannot realize that the main body of two sets of active filter compensators can share a single support beam, it cannot save the number of support beams installed, and the support beam occupies the limited space inside the single-door cabinet.

[0006] To solve one of the above problems, an active filtering device is urgently needed. Utility Model Content

[0007] Based on the shortcomings of the prior art, the technical problem to be solved by this utility model is: how to realize that two sets of active filter compensators share a single support beam, thereby saving the number of support beams installed, reducing the space occupied by the support beams, and satisfying the arrangement and installation of multiple active filter compensators. To this end, an active filter device is provided.

[0008] The active filter device of this utility model includes an active filter compensator body A, an active filter compensator body B, and a single-door cabinet. The active filter compensator body is installed in the single-door cabinet. The single-door cabinet is characterized by having two sets of spaced-apart support beams. The front ends of the active filter compensator body A and the active filter compensator body B are respectively installed on the upper and lower sides of the support beams via the same connector A. The rear ends of the active filter compensator body A and the active filter compensator body B are respectively installed on the upper and lower sides of the support beams via the same connector B.

[0009] It allows two sets of active filter compensators to share a single support beam, saving on the number of support beams required, reducing the space occupied by the support beams, and accommodating the arrangement and installation of multiple active filter compensators.

[0010] Preferably, the cross section of the supporting beam is H-shaped, including a front side plate and a rear side plate that are parallel to each other. A web plate is vertically connected between the front side plate and the rear side plate. The bottom end of the active filter compensator body A is provided with a left connecting foot A and a right connecting foot A, respectively. The top end of the active filter compensator body B is provided with a left connecting foot B and a right connecting foot B, respectively. The connecting piece A includes an upper pressure plate pressed against the left connecting foot A and a lower support plate pressed against the left connecting foot B. The other end of the upper pressure plate has a positioning bend A. The front side plate and the rear side plate are provided with positioning slots A that cooperate with the positioning bend A. The other end of the lower support plate has a positioning bend B. The front side plate and the rear side plate are provided with positioning slots B that cooperate with the positioning bend B. It also includes a threaded rod that passes through the upper pressure plate, the web plate, and the lower support plate. The upper end of the threaded rod is threaded with an upper nut, and the bottom end of the threaded rod is threaded with a lower nut.

[0011] The active filter compensator body A and active filter compensator body B are placed on the upper and lower sides of the support beam, respectively. First, place the two sets of active filter compensator bodies in position, then press the upper pressure plate and lower support plate onto the left connecting foot A and the left connecting foot B, respectively. Finally, use the threaded rod, upper nut, and lower nut to connect the upper pressure plate and lower support plate to the support beam. At the same time, the upper pressure plate and lower support plate can fix the left connecting foot A and the left connecting foot B to the support beam.

[0012] Preferably, the connector B has the same structure as the connector A.

[0013] Preferably, the active filter compensator body A is used to be connected in parallel to the three-phase power grid transmission line between the sampling and detection system and the three-phase AC power supply. It includes a control system and an external control system, a PWM modulation circuit, and a sampling and detection system electrically connected to the control system. It also includes an LC filter circuit. The LC filter circuit is connected to the three-phase AC power supply through wires. The LC filter circuit, the PWM modulation circuit, and the high-frequency absorption unit are connected in sequence through wires. The external control system, the charging circuit, and the controllable switch are connected in sequence through wires. A controllable switch is installed on the wire between the charging circuit and the LC filter circuit.

[0014] Preferably, the sampling and detection system is connected to the three-phase power grid transmission line to measure the load current or grid current and send it to the control system for processing. The control system completes the calculation of load harmonic current and closed-loop control of harmonic current compensation, and generates a PWM drive signal to the PWM modulation circuit. The PWM modulation circuit drives the inverter's IGBT to output the required compensation current to the grid, thus completing the harmonic filtering function.

[0015] Preferably, it further includes a high-frequency absorption unit connected to the transmission line, wherein the high-frequency absorption unit is subsequently connected to the control system.

[0016] Preferably, the charging circuit includes an IGBT module and a charging capacitor.

[0017] Preferably, the LC filter circuit includes capacitors C1, C2, and C3 connected in parallel.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The active filter device described in this utility model can realize two sets of active filter compensator bodies sharing a single support beam, saving the number of support beams required, reducing the space occupied by the support beams, and satisfying the arrangement and installation of multiple active filter compensator bodies.

[0020] The active filter device described in this utility model measures the load current or grid current through a sampling and detection system and sends it to the signal board for processing. The main controller completes the calculation of load harmonic current and closed-loop control of harmonic current compensation, and generates a PWM drive signal to the drive board. The drive board drives the inverter's IGBT to output the required compensation current to the grid, thus completing the harmonic filtering function. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0022] Figure 1 This is a diagram of the internal structure of the present invention;

[0023] Figure 2 for Figure 1 A partial view;

[0024] Figure 3 The structural principle of this active filter compensator Figure 1 ;

[0025] Figure 4 The structural principle of this active filter compensator Figure 2 ;

[0026] In the diagram: 1. Control system; 2. External control system; 3. Charging circuit; 4. Controllable switch; 5. Three-phase AC power supply; 6. LC filter circuit; 7. PWM modulation circuit; 8. DC filter circuit; 9. High-frequency absorption unit; 10. Sampling and detection system; 11. Nonlinear integrated load; 12. Single-door cabinet; 13. Support beam; 14. Active filter compensator body A; 15. Left connecting foot A; 16. Left connecting foot B; 17. Upper pressure plate; 18. Positioning bend A; 19. Lower support plate; 20. Positioning bend B; 21. Positioning slot A; 22. Positioning slot B; 23. Threaded rod; 24. Upper nut; 25. Lower nut. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings: The present invention will be further described below through specific embodiments, but it is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0028] Example 1, such as Figure 1-2 As shown, the active filter device includes an active filter compensator body A, an active filter compensator body B, and a single-door cabinet. The active filter compensator body is installed in the single-door cabinet. The single-door cabinet 13 is provided with two sets of spaced-apart support beams 14. The front ends of the active filter compensator body A 15 and the active filter compensator body B are respectively installed on the upper and lower sides of the support beams 14 through the same connector A. The rear ends of the active filter compensator body A and the active filter compensator body B are respectively installed on the upper and lower sides of the support beams 14 through the same connector B.

[0029] This allows two sets of active filter compensators to share a single support beam 14, saving on the number of support beams 14 required, reducing the space occupied by the support beams 14, and accommodating the arrangement and installation of multiple active filter compensators.

[0030] Example 2, as Figure 1-2 As shown, the active filter device includes an active filter compensator body A, an active filter compensator body B, and a single-door cabinet. The active filter compensator body is installed in the single-door cabinet. The single-door cabinet 13 is provided with two sets of spaced-apart support beams 14. The front ends of the active filter compensator body A 15 and the active filter compensator body B are respectively installed on the upper and lower sides of the support beams 14 through the same connector A. The rear ends of the active filter compensator body A and the active filter compensator body B are respectively installed on the upper and lower sides of the support beams 14 through the same connector B.

[0031] Furthermore, the cross section of the supporting beam 14 is H-shaped, including a front side plate and a rear side plate that are parallel to each other. A web plate is vertically connected between the front side plate and the rear side plate. The bottom end of the active filter compensator body A is respectively provided with a left connecting foot A16 and a right connecting foot A. The top end of the active filter compensator body B is respectively provided with a 17 and a right connecting foot B. The connecting piece A includes an upper pressure plate 18 pressed against the left connecting foot A16 and a lower support plate 20 pressed against the left connecting foot B17. The other end of the plate 18 has a positioning bend A19. The front and rear side plates are provided with positioning slots A22 that cooperate with the positioning bend A19. The other end of the lower support plate 20 has a positioning bend B21. The front and rear side plates are provided with positioning slots B23 that cooperate with the positioning bend B21. It also includes a threaded rod 24 that passes through the upper pressure plate 18, the web plate, and the lower support plate 20. The upper end of the threaded rod 24 is threaded with an upper nut 25, and the bottom end of the threaded rod 24 is threaded with a lower nut 26.

[0032] The active filter compensator body A15 and the active filter compensator body B are placed on the upper and lower sides of the support beam 14, respectively. First, the two sets of active filter compensator bodies are placed in place. Then, the upper pressure plate 18 and the lower support plate 20 are pressed onto the left connecting foot A16 and the left connecting foot B17, respectively. Finally, the upper pressure plate 18 and the lower support plate 20 are connected to the support beam 14 using the threaded rod 24, the upper nut 25, and the lower nut 26. At the same time, the upper pressure plate 18 and the lower support plate 20 can fix the left connecting foot A16 and the left connecting foot B17 to the support beam 14.

[0033] Furthermore, the connector B has the same structure as the connector A.

[0034] Furthermore, referring to Figure 3-4 The active filter compensator body A is used to be connected in parallel to the three-phase power grid transmission line between the sampling and detection system 10 and the three-phase AC power supply 11. It includes a control system 1 and an external control system 2, a PWM modulation circuit 7, and a sampling and detection system 10 that are electrically connected to the control system 1. The LC filter circuit 6 is connected to the three-phase AC power supply 5 through wires. The LC filter circuit 6, the PWM modulation circuit 7, and the high-frequency absorption unit 9 are connected in sequence through wires. The external control system 2, the charging circuit 3, and the controllable switch 4 are connected in sequence through wires. The controllable switch 4 is installed on the wire between the charging circuit 3 and the LC filter circuit 6.

[0035] Furthermore, the sampling and detection system 10 is connected to the three-phase power grid transmission line to measure the load current or grid current and send it to the control system 1 for processing. The control system 1 completes the calculation of load harmonic current and closed-loop control of harmonic current compensation, and generates a PWM drive signal to the PWM modulation circuit 7. The PWM modulation circuit 7 drives the inverter's IGBT to output the required compensation current to the power grid, thus completing the harmonic filtering function.

[0036] Furthermore, it also includes a high-frequency absorption unit 12 connected to the transmission line, wherein the high-frequency absorption unit 9 is subsequently connected to the control system 1.

[0037] Furthermore, the charging circuit 3 includes an IGBT module and a charging capacitor.

[0038] Furthermore, the LC filter circuit 6 includes capacitors C1, C2, and C3 connected in parallel.

[0039] After the switch is closed, the active power filter (APF) first charges the capacitor through a current-limiting resistor to limit the instantaneous inrush current upon power-up. Once the capacitor voltage reaches its rated value, the contactor automatically closes, and the device begins operation. The capacitor, acting as an energy storage element, provides energy for the compensation current output through the IGBT inverter and internal reactor.

[0040] Meanwhile, the capacitor provides operating power to the control and monitoring system through the power board.

[0041] The APF measures the load current or grid current through the sampling and detection system 10 and sends it to the signal board for processing. The main controller completes the calculation of load harmonic current and closed-loop control of harmonic current compensation, and generates a PWM drive signal to the drive board. The drive board drives the inverter's IGBT to output the required compensation current to the grid, thus completing the harmonic filtering function.

[0042] Active power filters (APFs) extract harmonics from the grid current using harmonic current detection technology and invert them to generate an anti-harmonic current. This anti-harmonic current, generated by the inverter main circuit, is injected into the grid to cancel out the harmonic currents. With current tracking technology, the generated anti-harmonic current is stably and rapidly input into the grid to cancel out the harmonic components. Modern digital signal acquisition and processing technologies, along with advanced IGBT conversion technology, enable the active injection of anti-harmonic current. A single unit can filter out 2-50th order full-spectrum harmonic currents without resonance risks. Even when the system harmonic current exceeds the APF capacity, the filter maintains full-load output without overload damage. There are no load change lags; it quickly follows changes, with a response time as low as 1 millisecond. It is suitable for complex systems with frequent load changes and diverse load types posing harmonic source loads. Active power filters (APFs) use harmonic current detection technology to extract harmonics from the grid current and invert them to generate "anti-harmonic currents." These "anti-harmonic currents" are then generated by the inverter main circuit and injected into the grid to cancel out the harmonic currents in the grid. With the help of current tracking technology, the generated anti-harmonic current is stably and quickly input into the grid to cancel out the harmonic components of the grid.

[0043] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

[0044] Any aspects of this invention not described in detail are well-known to those skilled in the art.

Claims

1. An active filter device, comprising an active filter compensator body A, an active filter compensator body B, and a single-door cabinet, wherein the active filter compensator body is installed within the single-door cabinet, characterized in that: The single-door cabinet is equipped with two sets of spaced-apart support beams. The front ends of the active filter compensator body A and the active filter compensator body B are respectively installed on the upper and lower sides of the support beams through the same connector A. The rear ends of the active filter compensator body A and the active filter compensator body B are respectively installed on the upper and lower sides of the support beams through the same connector B.

2. The active filter device according to claim 1, characterized in that, The supporting beam has an H-shaped cross-section and includes a front side plate and a rear side plate that are parallel to each other. A web plate is vertically connected between the front side plate and the rear side plate. The bottom of the active filter compensator body A is provided with a left connecting foot A and a right connecting foot A, respectively. The top of the active filter compensator body B is provided with a pressing foot B on the left side connecting foot B and a pressing foot B on the right side connecting foot B, respectively. The connecting piece A includes an upper pressure plate pressing on the left connecting foot A and a lower support plate pressing on the left connecting foot B. The other end of the upper pressure plate has a positioning bend A. The front side plate and the rear side plate have positioning slots A that cooperate with the positioning bend A. The other end of the lower support plate has a positioning bend B. The front side plate and the rear side plate have positioning slots B that cooperate with the positioning bend B. It also includes a threaded rod that passes through the upper pressure plate, the web plate, and the lower support plate. The upper end of the threaded rod is threaded with an upper nut, and the bottom end of the threaded rod is threaded with a lower nut.

3. The active filter device according to claim 2, characterized in that, The active filter compensator body A is used to be connected in parallel to the three-phase power grid transmission line between the sampling and detection system and the three-phase AC power supply. It includes a control system and an external control system, a PWM modulation circuit, and a sampling and detection system electrically connected to the control system. It also includes an LC filter circuit. The LC filter circuit is connected to the three-phase AC power supply through wires. The LC filter circuit, the PWM modulation circuit, and the high-frequency absorption unit are connected in sequence through wires. The external control system, the charging circuit, and the controllable switch are connected in sequence through wires. A controllable switch is installed on the wire between the charging circuit and the LC filter circuit.

4. The active filter device according to claim 3, characterized in that, The sampling and detection system is connected to the three-phase power grid transmission line to measure the load current or grid current and send it to the control system for processing. The control system completes the calculation of load harmonic current and closed-loop control of harmonic current compensation, and generates a PWM drive signal to the PWM modulation circuit. The PWM modulation circuit drives the inverter's IGBT to output the required compensation current to the grid, thus completing the harmonic filtering function.

5. The active filter device according to claim 4, characterized in that, It also includes a high-frequency absorption unit connected to the power transmission line, which is subsequently connected to the control system.

6. The active filter device according to claim 5, characterized in that, The charging circuit includes an IGBT module and a charging capacitor.

7. The active filter device according to claim 6, characterized in that, The LC filter circuit includes capacitors C1, C2, and C3 connected in parallel.

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