TWI481173B - An isolated power factor corrector - Google Patents

Description

Isolated power factor corrector

The present invention relates to a power factor circuit, and more particularly to an isolated power factor corrector.

The power factor refers to the relationship between the effective power and the total power consumption (apparent power), that is, the ratio of the effective power divided by the total power consumption (apparent power). Basically, the power factor can measure the degree to which power is effectively utilized. When the value of the power factor is larger, it means that the power utilization rate is higher. The power factor corrector on the power supply operates on the principle of controlling the time and waveform of the AC current input so that it is as consistent as possible with the DC voltage waveform, bringing the power factor closer to one. This is important for electronic devices that require a certain amount of power, otherwise the power consumed by the power system may exceed its specifications and is likely to interfere with other electronic devices. Under normal circumstances, when the electronic device does not have Power Factor Correction (PFC), its PF value is only about 0.5.

Benefits of power factor correction include: increasing power system capacity and stabilizing current. The low power factor represents low power efficiency. The lower the power factor value represents the higher proportion of power consumed in the distribution network. If the lower power factor is not corrected, the power company must provide The unrelated work of work, which leads to the need for larger generators, converters, conveyors, cables and additional distribution systems, can be omitted to compensate for the lack of wear and tear. PFC-enabled electronic devices can help improve energy usage and reduce electricity bills. PFC is also a Environmental protection technology can effectively reduce the harmonics that cause power pollution, and is a useful function for all of society.

Nowadays, due to the advancement of technology, a large number of electrical appliances are used differently. Most of the AC-to-DC circuits in the power factor correction circuit use bridge rectifier circuits, but the bridge voltage is too large, so the bridge is too large. In view of the fact that the power consumption of the rear circuit is too large, it is necessary to study a circuit with low power consumption.

Therefore, the object of the present invention is to provide one, including: thus, the effect of the present invention lies in

The details of the related patents and the technical contents of the present invention will be apparent from the following detailed description of a preferred embodiment of the drawings.

Referring to FIG. 1 , a preferred embodiment of the present invention is an isolated power factor corrector comprising: a controller 10, a first diode D1, a first transistor M1, a third diode D3, and a first inductor. L1, second diode D2, second transistor M2, second transistor M2, fourth diode D4, first capacitor C1, second inductor L2, fifth diode D5, second capacitor C2 Transformer T1, sixth diode D6, third capacitor C3 and resistive load RL. The controller 10 generates a first pulse wave and a second pulse wave. The first end of the first transistor M1 is connected to the first end (N-type) of the first diode D1, and the second end of the first transistor M1 is connected to the first pulse of the controller 10, the first transistor The third end of M1 is connected to the second side of an alternating current. Third diode D3 The first end (N-type) is connected to the first end of the first transistor M1, and the second end (P-type) of the third diode D3 is connected to the third end of the first transistor M1. The first end of the first inductor L1 is connected to the second end (P type) of the first diode D1, and the second end of the first inductor L1 is connected to the first side of the alternating current. The first end (N-type) of the second diode D2 is connected to the second end (P-type) of the first diode D1. The first end of the second transistor M2 is connected to the third end of the second transistor M2, the second end of the second transistor M2 is connected to the second pulse of the controller 10, and the third end of the second transistor M2 Connected to the second end (P-type) of the second diode D2. The first end of the fourth diode D4 (N-type) is connected to the first end of the second transistor M2, and the second end of the fourth diode D4 (P-type) is connected to the third end of the second transistor M2 end. The first end of the first capacitor C1 is connected to the first end of the first transistor M1. The first end of the second inductor L2 is connected to the first end of the first capacitor C1. The first end (P type) of the fifth diode D5 is connected to the second end of the first capacitor C1, and the second end (N type) of the fifth diode D5 is connected to the second end of the first inductor L1 . The first end of the second capacitor C2 is connected to the second end (N-type) of the fifth diode D5, and the second end of the second capacitor C2 is connected to the third end of the second transistor M2. The transformer T1 has a first side and a second side, a first end of the first side of the transformer T1 is connected to the second end of the first capacitor C1, and a second end of the first side of the transformer T1 is connected to the second transistor The third end of M2. The first end (P-type) of the sixth diode D6 is connected to the first end of the second side of the transformer T1. The first end of the third capacitor C3 is connected to the second end (N-type) of the sixth diode D6, and the second end of the third capacitor C3 is connected to the second end of the second side of the transformer T1. The first end of the resistive load RL is connected to the second end of the sixth diode D6, and the resistance load RL is The second end is connected to the second end of the second side of the transformer T1.

The first transistor M1 and the first transistor M2 are selected from the group consisting of: a junction field effect transistor and a gold oxide half field effect transistor. The first transistor M1 has three ends, the first end of the first transistor M1 is a drain, the second end is a gate, and the third end is a source. The second transistor M2 has three ends, the first end of the second transistor M2 is a drain, the second end is a gate, and the third end is a source.

The controller 10 is selected from the group consisting of: a microcontroller (Micro-controller), an ARM (ARM) controller, and a digital signal processing (DSP) controller.

Next, referring to FIG. 2, the primary side equivalent model 50 of the transformer T1 of the present invention includes: a leakage inductance Lleak, a first magnetizing inductance Lm1 and a second magnetizing inductance Lm2. The first end of the leakage inductance Lleak is connected to the first end of the first capacitor C1. The first end of the first magnetizing inductance Lm1 is connected to the second end of the leakage inductance Lleak, and the second end of the first magnetizing inductance Lm1 is connected to the third end of the second transistor M2. The first end of the second magnetizing inductance Lm2 is connected to the second end of the leakage inductance Lleak, and the second end of the second magnetizing inductance Lm2 is connected to the third end of the second transistor M2.

The present invention operates in the case of an alternating current, wherein the alternating current can be divided into a positive half cycle and a negative half cycle, and FIGS. 3 and 4 operate in a positive half cycle, while FIGS. 4 and 5 operate in a negative half cycle.

Next, referring to FIG. 3, when the first pulse of the controller 10 is at a high potential and the second pulse of the controller 10 is at a high potential, at this time, the first transistor M1 switches and the second transistor M2. When the switch is turned on, the alternating current stores energy (path1) to the first inductor L1 via the first diode D1. Second capacitor C2 stores energy to the second inductor L2 (path 3). The current of the transformer T1 flows out from the first end of the first side of the transformer T1, and flows through the first capacitor C1, the first transistor M1, the second transistor M2, and the second end (path2) of the first side of the transformer T1. The primary side of the transformer T1 generates a first induced voltage, and the secondary side of the transformer T1 generates a second induced voltage. The polarity of the second induced voltage is different from the polarity of the sixth diode D6. At this time, the third capacitor C3 is opposite to the resistive load. RL discharge (path4).

Next, referring to FIG. 4, when the first pulse of the controller 10 is low and the second pulse of the controller 10 is low, at this time, the first transistor M1 switch and the second transistor M2 are switched. When turned off, the current on the primary side of the alternating current flows out through the first inductor L1, the first diode D1, the first capacitor C1, the fifth diode D5, the second capacitor C2, and the fourth diode D4 to the alternating current Secondary side (path5). The second inductor L2 charges the first capacitor C1 (path 6). The first terminal current of the first side of the transformer T1 flows out to charge the second capacitor C2 via the fifth diode D5 (path 7), and causes the first side of the transformer T1 to generate a third induced voltage. At this time, the transformer T1 The second side generates a fourth induced voltage. Since the fourth induced voltage has the same polarity as the sixth diode D6, the second induced voltage charges the third capacitor C3 (path 8).

Next, referring to FIG. 5, when the first pulse of the controller 10 is at a high potential and the second pulse of the controller 10 is at a high potential, at this time, the first transistor M1 switch and the second transistor M2 are turned on. At the time, the alternating current stores energy to the first inductor L1 via the second diode D2 (path 11). The second capacitor C2 stores energy to the second inductor L2 (path 13). Transformer T1 current by transformer The first end of the first side of T1 flows out, through the first capacitor C1, the first transistor M1, the second transistor M2, and flows into the second end (path 12) of the first side of the transformer T1, and the primary side of the transformer T1 is generated. The fifth induced voltage, and the secondary side of the transformer T1 generates a sixth induced voltage, and the sixth induced voltage is different from the sixth diode D6. At this time, the third capacitor C3 discharges the resistance load RL (path 14).

Next, referring to FIG. 6, when the first pulse of the controller 10 is low and the second pulse of the controller 10 is low, at this time, the first transistor M1 switch and the second transistor M2 are switched to When closed, the secondary side of the alternating current flows out through the third diode D3, the first capacitor C1, the fifth diode D5, the second capacitor C2, the second diode D2, the first inductor L1 to the alternating current Secondary side (path15). The second inductor L2 charges the first capacitor C1 (path 16). The first terminal current of the first side of the transformer T1 flows out to charge the second capacitor C2 via the fifth diode D5 (path 17), and causes the first side of the transformer T1 to generate a seventh induced voltage. At this time, the transformer T1 The second side generates an eighth induced voltage. Since the polarity of the eighth induced voltage is the same as the sixth diode D6, the eighth induced voltage charges the third capacitor C3 (path 18).

The first inductor L1 and the second inductor L2 are selected from the group consisting of: a hollow inductor, a core inductor and a core inductor.

The first capacitor C1, the second capacitor C2 and the third capacitor C3 are selected from the group consisting of: a paper capacitor, a ceramic capacitor, an aluminum electrolytic capacitor, a plastic film capacitor, a tantalum capacitor, a titanium capacitor and a Mica capacitors.

Wherein, the transformer T1 is selected from the group consisting of: a magnetic saturation transformer and a leakage magnetic transformer.

Wherein, the resistive load RL is selected from the group consisting of: a chip resistor, a carbon film resistor, a metal film resistor, a metal oxide film resistor, a wire wound resistor, a power type wire wound resistor, a cement resistor, and a thick film array resistor. With a fuse type metal film resistor.

Therefore, the object of the present invention is to provide a power factor correction circuit, which has not used a good high power factor correction circuit for converting AC to DC, and provides a new power factor correction circuit, which can obtain a high power factor. It also improves the problem of large power loss of the bridge circuit in the past, and makes the voltage and current in phase and reduce harmonics. In addition, the power loss required by the present invention is relatively small compared to the prior art, so that the power consumption can be reduced.

In summary, the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

10‧‧‧ Controller

50‧‧‧One-side equivalent model of transformer

M1‧‧‧first transistor

M2‧‧‧second transistor

D1‧‧‧First Diode

D2‧‧‧ second diode

D3‧‧‧ third diode

D4‧‧‧ fourth diode

D5‧‧‧ fifth diode

D6‧‧‧ sixth diode

T1‧‧‧ transformer

C1‧‧‧First Capacitor

C2‧‧‧second capacitor

C3‧‧‧ third capacitor

L1‧‧‧First Inductor

L2‧‧‧second inductor

Lleak‧‧‧Leakage inductance

Lm1‧‧‧first magnetizing inductance

Lm2‧‧‧second magnetizing inductance

RL‧‧‧resistive load

1 is an isolated power factor corrector of the present invention; FIG. 2 is a first side equivalent model diagram of the transformer of the isolated power factor corrector of the present invention; FIG. 3 is the first of the isolated power factor corrector of the present invention; Path map 4 is a second path diagram of the isolated power factor corrector of the present invention; FIG. 5 is a third path diagram of the isolated power factor corrector of the present invention; and FIG. 6 is an isolated power factor corrector of the present invention. The fourth path map.

10‧‧‧ Controller

M1‧‧‧first transistor

M2‧‧‧second transistor

D1‧‧‧First Diode

D2‧‧‧ second diode

D3‧‧‧ third diode

D4‧‧‧ fourth diode

D5‧‧‧ fifth diode

D6‧‧‧ sixth diode

T1‧‧‧ transformer

C1‧‧‧First Capacitor

C2‧‧‧second capacitor

C3‧‧‧ third capacitor

L1‧‧‧First Inductor

L2‧‧‧second inductor

RL‧‧‧resistive load

Claims (10)

An isolated power factor corrector comprising: a controller for generating a first pulse and a second pulse; a first diode; a first transistor, the first of the first transistor The end is connected to the first end of the first diode, the second end of the first transistor is connected to the first pulse of the controller, and the third end of the first transistor is connected to an alternating current a second diode; a first end of the third diode is connected to the first end of the first transistor, and a second end of the third diode is connected to the first transistor a third end; a first inductor, the first end of the first inductor is connected to the second end of the first diode, and the second end of the first inductor is connected to the first side of the alternating current; a second diode, the first end of the second diode is connected to the second end of the first diode; a second transistor, the first end of the second transistor is connected to the second a third end of the transistor, the second end of the second transistor is connected to the second pulse of the controller, and the third end of the second transistor is connected to the second diode a second end; a fourth diode, the first end of the fourth diode is connected to the first end of the second transistor, and the second end of the fourth diode is connected to the second a third end of the crystal; a first capacitor, the first end of the first capacitor being connected to the a first end of the first transistor; a second inductor having a first end connected to the first end of the first capacitor; a fifth diode, the fifth dipole One end is connected to the second end of the first capacitor, the second end of the fifth diode is connected to the second end of the first inductor; a second capacitor is connected to the first end of the second capacitor a second end of the second diode, the second end of the second capacitor is connected to the third end of the second transistor; a transformer having a first side and a second side, the transformer a first end of one side is connected to the second end of the first capacitor, and a second end of the first side of the transformer is connected to a third end of the second transistor; a sixth diode, the sixth a first end of the diode is connected to the first end of the second side of the transformer; a third capacitor, the first end of the third capacitor is connected to the second end of the sixth diode, the third capacitor a second end is connected to the second end of the second side of the transformer; and a resistive load, the first end of the resistive load is connected to the sixth a second end of the resistor, the second end of the resistive load is coupled to the second end of the second side of the transformer; wherein, when the first pulse of the controller is at a high potential and the second pulse of the controller When the wave is at a high potential, when the first transistor switch is turned on and the second transistor switch is turned on, the alternating current is passed through the first diode The second inductor stores energy for the second inductor, and the current of the transformer flows out of the first end of the first side of the transformer, via the first capacitor, the first a transistor, the second transistor and flowing into the second end of the first side of the transformer, the primary side of the transformer generates a first induced voltage, and the secondary side of the transformer generates a second induced voltage, the second induced voltage The polarity of the sixth diode is different from the polarity of the sixth diode. At this time, the third capacitor discharges the resistance load; when the first pulse of the controller is low and the second pulse of the controller is When the potential is low, the first transistor switch and the second transistor switch are turned off, and the primary side of the alternating current flows out through the first inductor, the first diode, the first capacitor, and the fifth diode The second capacitor and the fourth diode are connected to the secondary side of the alternating current, the second inductor charges the first capacitor, and the first end current of the first side of the transformer flows out through the fifth The pole body charges the second capacitor, and The first side of the transformer generates a third induced voltage. At this time, the second side of the transformer generates a fourth induced voltage. Since the polarity of the fourth induced voltage is the same as the polarity of the sixth diode, the first The fourth induced voltage charges the third capacitor; when the first pulse of the controller is at a high potential and the second pulse of the controller is at a high potential, the first transistor switch and the second transistor When the switch is turned on, the alternating current stores energy to the first inductor via the second diode, and the second capacitor stores energy to the second inductor, the current of the transformer is first by the first side of the transformer End flowing out through the first capacitor, the first transistor, the second transistor And flowing into the second end of the first side of the transformer, the primary side of the transformer generates a fifth induced voltage, and the secondary side of the transformer generates a sixth induced voltage, the sixth induced voltage being different from the sixth diode Body, at this time, the third capacitor discharges the resistive load; when the first pulse of the controller is low and the second pulse of the controller is low, the first transistor switch The second transistor switch is turned off, and the secondary side of the alternating current flows out through the third diode, the first capacitor, the fifth diode, the second capacitor, the second diode, and the first An inductor is connected to the secondary side of the alternating current, the second inductor charges the first capacitor, and the first end current of the first side of the transformer flows out to charge the second capacitor via the fifth diode, and The first side of the transformer generates a seventh induced voltage. At this time, the second side of the transformer generates an eighth induced voltage. Since the polarity of the eighth induced voltage is the same as the sixth diode, the eighth Inductive voltage is charged to the third capacitor . The isolated power factor corrector according to claim 1, wherein the first electro-crystalline system is selected from the group consisting of: a junction field effect transistor and a gold oxide half field effect transistor. The isolated power factor corrector according to claim 1, wherein the second electro-crystalline system is selected from the group consisting of: a junction field effect transistor and a gold oxide half field effect transistor. The isolated power factor corrector according to claim 1, wherein the controller is selected from the group consisting of: a microcontroller, a security controller, and a digital signal processing controller. The isolated power factor corrector according to claim 1, wherein the first inductor is selected from the group consisting of: a hollow inductor, a core inductor and a core inductor. The isolated power factor corrector according to claim 1, wherein the second inductor is selected from the group consisting of: a hollow inductor, a core inductor and a core inductor. The isolated power factor corrector according to claim 1, wherein the first capacitor is selected from the group consisting of: a paper capacitor, a ceramic capacitor, an aluminum electrolytic capacitor, a plastic film capacitor, and a tantalum capacitor. , a titanium capacitor and a mica capacitor. The isolated power factor corrector according to claim 1, wherein the second capacitor is selected from the group consisting of: a paper capacitor, a ceramic capacitor, an aluminum electrolytic capacitor, a plastic film capacitor, and a tantalum capacitor. , a titanium capacitor and a mica capacitor. The isolated power factor corrector according to claim 1, wherein the third capacitor is selected from the group consisting of: a paper capacitor, a ceramic capacitor, an aluminum electrolytic capacitor, a plastic film capacitor, and a tantalum capacitor. , a titanium capacitor and a mica capacitor. The isolated power factor corrector according to claim 1, wherein the transformer is selected from the group consisting of: a magnetic saturation transformer and a magnetic flux leakage transformer.