TWM592190U - Active filter transformer with elimination of power harmonic - Google Patents

Abstract

This invention creates an active filter transformer with power harmonic elimination, coupled between a power system and a load. The active filter transformer includes at least: a transformer with a high voltage side and a low voltage side, the high voltage side coupling Connected to the power system, the low-voltage side is coupled to the load to convert the high voltage of the power system into a low voltage for the load; and an active filter with a monitoring terminal and a compensation output terminal, the The monitoring terminal is used to monitor the current waveform of the load in real time. When a harmonic current is detected on the detection side, a compensation current equal to the harmonic current and opposite in phase is generated through operation, and output to the transformer through the compensation output terminal. Low-voltage side to eliminate the harmonic current, so that the power system contains only the fundamental wave, to achieve the purpose of eliminating power harmonics.

Description

Active filter transformer with power harmonic elimination

This creation is about an active filter transformer with the elimination of power harmonics, especially a combination of active filters and transformers to form a new type of active filter transformer, which can eliminate power harmonics and Power pollution such as power spikes (surge).

Power quality pollution in power systems includes: power spikes (surges) and power harmonics. Power spikes (surges) can cause insulation damage or insulation breakdown of transformers in the power system, causing short-circuiting of transformer windings, so traditional power technicians will use Surge-resistant transformers to solve the problem of power spikes (surges).

Harmonic power is caused by non-linear loads in the power distribution system, such as harmonic currents generated by variable-frequency loads such as motors and compressors. Harmonic voltages are generated after the return system, which deforms the sine wave of the power system , Resulting in the increase of virtual work and noise caused by the conversion of cable wires, power distribution components or electrical equipment into heat loss, and serious damage to the equipment.

Harmonic filters can be used in power systems to filter out harmonics in power systems. Harmonic filters are divided into passive filters (passive filters) and active filters (active filters). The filter is composed of an inductor and a capacitor. The LC filter, and the active filter includes active electronic components such as transistor switches or operational amplifiers in addition to the inductor and capacitor. Due to the use of an independent power supply, the signal source is better isolated from the load circuit .

The principle of Active Harmonic Filter (AHF) is to detect the harmonics on the power grid and the voltage and current of the compensation object in real time, calculate the compensation current signal through the arithmetic unit, and control the power electronic components to generate and harmonic current magnitude Compensation currents that are equal and opposite in phase are fed back into the power system with harmonic current components to filter out harmonics on the power system. Generally, the filtering effect of the active filter is better than that of the passive filter, and it also has the virtual power compensation effect of current feedback.

However, the current power distribution system uses harmonic resistant, surge type (SK type) transformer 10 combined with passive filter 20, as shown in the schematic diagram of FIG. 1, to solve the problem of power pollution, but passive filter 20 can only absorb the load 30 is about 60~70% of power harmonics, so 30~40% of power harmonics of load 30 will be fed back to the power system, and harmonic resistant, surge type (SK type) transformer 10 is expensive, and passive filtering The device 20 can only protect the transformer in a limited manner, and cannot protect the entire power system. Therefore, the power quality of the power system is unstable, and the configuration cost of the power system is increased, so there is still room for improvement.

In order to solve the above-mentioned lack of knowledge, the purpose of this writing is to propose an active filter transformer with the elimination of power harmonics. It does not require the use of harmonic resistant, surge (SK type) transformers, but directly uses active filtering The transformer eliminates power pollution caused by power spikes (suds) and power harmonics. Not only is the price more economical, but also the power harmonics of the power supply system can be lower than 5%~10% to protect the power system lines and equipment Stable power quality.

To achieve the above objective, the main technical feature of this creation is to provide an active filter transformer with power harmonic elimination coupled between a power system and a load. The active filter transformer includes at least a transformer with A high-pressure side and a low-pressure side, the high The low voltage side is coupled to the power system, and the low voltage side is coupled to the load to convert the high voltage of the power system into a low voltage for the load; and an active filter with a monitoring terminal and a compensation output The monitoring terminal is used to monitor the current waveform of the load in real time. When a harmonic current is detected, a compensation current equal to the harmonic current and opposite in phase is generated through operation, and output to the compensation output through the compensation output terminal. The low-voltage side of the transformer eliminates the harmonic current, so that the power supply system contains only the fundamental wave, and the purpose of eliminating power harmonics is achieved.

In order to achieve the above purpose, the secondary technical feature of this creation is to provide the above active filter transformer with power harmonic elimination, wherein the active filter further includes: a current transformer with a primary winding group and a secondary side Winding set, the low-voltage side line of the transformer runs through the primary winding set to the load, and is used to induce a high current flowing through the load to induce a low current in the secondary winding set and couple it to the monitoring end of the active filter. .

In order to achieve the above purpose, yet another technical feature of this creation is to provide the above active filter transformer with power harmonic elimination, which further includes: a fuseless switch (NFB) and a surge absorber, a fuseless switch It is coupled between the low-voltage side of the transformer and the compensation output of the active filter to protect the active filter; the surge absorber is coupled between the low-voltage side of the transformer and a ground to absorb power Power spikes (bursts) on the system.

10‧‧‧Harmonic resistance, surge type (SK type) transformer

20‧‧‧passive filter

30‧‧‧load

40‧‧‧Transformer

41‧‧‧High pressure side

42‧‧‧Low pressure side

50‧‧‧Flower

51‧‧‧ Primary side winding group

52‧‧‧Secondary side winding group

60‧‧‧Active filter

61‧‧‧Monitor

62‧‧‧Compensation output

70‧‧‧ No fuse switch

80‧‧‧Surge absorber

100‧‧‧filter transformer

Figure 1 is a schematic diagram of a harmonic resistant, surge type (SK type) transformer combined with a passive filter.

Figure 2 is a schematic diagram of the system architecture for creating an active filter transformer.

Figure 3 is a block diagram of the creation of an active filter transformer.

Figure 4 is a schematic diagram of the combination of the creation of the active filter transformer.

Please refer to FIGS. 2 to 4 together. FIG. 2 is a schematic diagram of the system architecture of the active filter transformer, FIG. 3 is a block diagram of the active filter transformer, and FIG. 4 is a view of the active filter transformer. Schematic diagram of disk combination. As shown in FIGS. 2 and 4, the active filter transformer 100 with power harmonic elimination of the present invention is connected to the power line between the high-voltage disk of the power system and the low-voltage disk of the user load. The load 30 on the user side may include devices such as an inverter, a motor, a transformer, a motor, a compressor, etc., and a filter function is further connected between the filter transformer 100 and the load 30 Because of the improved disk, the passive filter 20.

As shown in FIG. 3, the filter transformer 100 of the present invention includes a transformer 40, a current transformer 50, an active filter 60, a fuseless switch 70 and a surge absorber 80, wherein the transformer 40 has a A high voltage side 41 and a low voltage side 42. The high voltage side 41 is coupled to the high voltage disk of the power system. The low voltage side 42 is coupled to the voltage disk of the load 30. The transformer 40 is used to convert the high voltage of the power system into Low voltage for load 30.

The current transformer 50 has a primary winding group 51 (not shown in the figure) and a secondary winding group 52 (not shown in the figure). The low-voltage side 42 of the transformer 40 passes through the primary side of the current converter 50 The winding 51 is grouped to the load 30 to induce a high current flowing through the load 30 to induce a low current on the secondary winding group 52. The active filter 60 has a monitoring terminal 61 and a compensating output terminal 62. The monitoring terminal 61 is coupled to the secondary winding 52 of the current comparator for real-time monitoring of the current waveform of the load 30 When a harmonic current is detected on the monitoring end 61, the active filter 60 generates a compensation current equal to the harmonic current and opposite in phase, and then outputs it to the transformer 40 through the compensation output 62 Low-voltage side 42 to eliminate the harmonic current, so that the power system contains only There is a fundamental wave to achieve the purpose of eliminating power harmonics.

The non-fuse switch (NFB) 70 is coupled between the low voltage side 42 of the transformer 40 and the compensation output 62 of the active filter 60 to protect the active filter 60. The surge absorber 80 is coupled between the low-voltage side 42 of the transformer 40 and a ground terminal to absorb the power spike (surge) wave on the power system and avoid the use of an expensive surge-resistant type (SK type) )transformer.

As shown in FIG. 2 again, the active filter transformer 100 of the present invention combined with the filter power improvement disk (passive filter 20) can absorb 100% of the power harmonics from the load by the passive filter 20 to absorb about 60% ~70% harmonics, then the remaining 30%~40% harmonics are filtered by the active filter 60 on the filter transformer 100, so the power harmonics flowing into the power system will not exceed 5%~10%, reaching The purpose of eliminating power harmonics so that the power system contains only the fundamental wave.

In summary, the active filter transformer with harmonic current elimination does not need to use harmonic resistant, surge type (SK type) transformers, but the use of the filter transformer with the filter power improvement disk can eliminate power spikes. (Suddenly) Power pollution that affects power harmonics is not only innovative in terms of technical ideas, but also can improve the above-mentioned multiple effects compared to conventional items. It should be based on the legal patent requirements that fully meet the novelty and progress. Your bureau approves this new type of patent case, to encourage creation, and feel virtuous.

30‧‧‧load

40‧‧‧Transformer

41‧‧‧High pressure side

42‧‧‧Low pressure side

50‧‧‧Flower

51‧‧‧ Primary side winding group

52‧‧‧Secondary side winding group

60‧‧‧Active filter

61‧‧‧Monitor

62‧‧‧Compensation output

70‧‧‧ No fuse switch

80‧‧‧Surge absorber

Claims (6)

An active filter transformer with power harmonic elimination is coupled between a power system and a load. The active filter transformer includes at least: A transformer having a high-voltage side and a low-voltage side, the high-voltage side is coupled to the power system, and the low-voltage side is coupled to the load for converting the high voltage of the power system into a low voltage for use by the load; and An active filter has a monitoring terminal and a compensation output terminal. The monitoring terminal is used to monitor the current waveform of the load in real time. A compensation current with opposite phase is output to the low-voltage side of the transformer through the compensation output terminal to eliminate the harmonic current, so that the power supply system contains only the fundamental wave, and the purpose of eliminating power harmonics is achieved. The active filter transformer with power harmonic elimination according to claim 1, wherein the active filter further includes: A current transformer with a primary side winding set and a secondary side winding set, the low-voltage side line of the transformer penetrates the primary side winding set to the load, used to pass the high current flowing through the load, in The secondary winding group induces a low current to be coupled to the monitoring end of the active filter. The active filter transformer with power harmonic elimination as described in claim 1 further includes: A fuseless switch (NFB) is coupled between the low voltage side of the transformer and the compensation output of the active filter to protect the active filter. The active filter transformer with power harmonic elimination as described in claim 1 further includes: A surge absorber is coupled between the low-voltage side of the transformer and a ground terminal to absorb power spikes (surges) on the power system. The active filter transformer with power harmonic elimination according to claim 1, wherein the active filter is further coupled to a filter power improvement disk for absorbing power harmonics from the load. An active filter transformer with power harmonic elimination as described in claim 5, wherein the filter power improvement disk can absorb about 60% to 70% of the harmonics, and then filter out about 30% by the active filter ~40% harmonics make the harmonics flowing into the power system lower than 5%~10%.

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